Crossbow with dual track cam assembly

Abstract

A crossbow includes a drawstring including a left loop portion, a right loop portion, and a center portion extending between the left loop portion and the right loop portion, and a cam assembly including a first cam and a second cam. The first cam is rotatable about a first cam axis and includes an upper drawstring journal and a lower drawstring journal configured to receive the right loop portion of the drawstring. The upper drawstring journal of the first cam and the lower drawstring journal of the first cam are vertically offset from each other. The second cam is rotatable about a second cam axis and includes an upper drawstring journal and a lower drawstring journal configured to receive the left loop portion of the drawstring. The upper drawstring journal of the second cam and the lower drawstring journal of the second cam are vertically offset from each other.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Ser. No. 63 / 619,188, filed Jan. 9, 2024, which is incorporated herein by reference in its entirety.BACKGROUND

[0002] This application relates generally to a projectile launcher.SUMMARY

[0003] One embodiment relates to a crossbow. The crossbow includes a frame, a limb assembly coupled to the frame, a drawstring including a left loop portion, a right loop portion, and a center portion extending between the left loop portion and the right loop portion, and a cam assembly rotatably coupled with the limb assembly. The limb assembly includes a first upper limb, a first lower limb, a second upper limb, and a second lower limb. The cam assembly includes a first cam rotatable about a first cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the right loop portion of the drawstring, and a second cam rotatable about a second cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the left loop portion of the drawstring. The upper drawstring journal of the first cam and the lower drawstring journal of the first cam are vertically offset from each other. The upper drawstring journal of the second cam and the lower drawstring journal of the second cam are vertically offset from each other.

[0004] Another embodiment relates to a cam assembly. The cam assembly includes a drawstring including a left loop portion, a right loop portion, and a center portion extending between the left loop portion and the right loop portion, a first cam rotatable about a first cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the right loop portion of the drawstring, and a second cam rotatable about a second cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the left loop portion of the drawstring. The first cam includes a first upper cable guide extending from a top surface of the first cam along the first cam axis, and a first lower cable guide extending from a bottom surface of the first cam along the first cam axis, such that the upper drawstring journal and the lower drawstring journal of the first cam are positioned between the first upper cable guide and the first lower cable guide. The second cam includes a second upper cable guide extending from a top surface of the second cam along the second cam axis, and a second lower cable guide extending from a bottom surface of the second cam along the second cam axis, such that the upper drawstring journal and the lower drawstring journal of the second cam are positioned between the second upper cable guide and the second lower cable guide.

[0005] Another embodiment relates to a method of manufacturing a drawstring. The method includes providing a plurality of inner strings and serving material, twisting the plurality of inner strings to form a core of the drawstring, joining opposite ends of the core to form a continuous loop, twisting the continuous loop such that a center portion of the continuous loop is twisted, a left side of the continuous loop forms a left loop portion, and a right side of the continuous loop forms a right loop portion, serving at least a portion of the left loop portion using the serving material, serving at least a portion of the right loop portion using the serving material, and serving at least a portion of the center portion using the serving material. A first portion of the left loop portion is served in a first direction using the serving material. A second portion of the left loop portion is served in a second direction using the serving material. A first portion of the right loop portion is served in the first direction using the serving material. A second portion of the right loop portion is served in the second direction using the serving material. The first direction is opposite the second direction.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a left side view of a crossbow, according to an exemplary embodiment.

[0007] FIG. 2 is a top view of the crossbow of FIG. 1, according to an exemplary embodiment.

[0008] FIG. 3 is a front view of the crossbow of FIG. 1, according to an exemplary embodiment.

[0009] FIG. 4 is a rear view of the crossbow of FIG. 1, according to an exemplary embodiment.

[0010] FIG. 5 is a rear view of the crossbow of FIG. 1 with a frame and a string cover removed, according to an exemplary embodiment.

[0011] FIG. 6 is a top view of the crossbow of FIG. 1, according to an exemplary embodiment.

[0012] FIG. 7a is a top view of a right cam of a cam assembly of the crossbow of FIG. 1, according to an exemplary embodiment.

[0013] FIG. 7b is a side view of the right cam of the cam assembly of the crossbow of FIG. 1, according to an exemplary embodiment.

[0014] FIG. 8a is a top view of a left cam of the cam assembly of the crossbow of FIG. 1, according to an exemplary embodiment.

[0015] FIG. 8b is a side view of the left cam of the cam assembly of the crossbow of FIG. 1, according to an exemplary embodiment.

[0016] FIG. 9 is a rear view of a drawstring, according to an exemplary embodiment.

[0017] FIGS. 10A-13 are various views of a method of manufacturing the drawstring of FIG. 9, according to an exemplary embodiment.

[0018] FIG. 14 is a detailed view of left and right loop portions of the drawstring of FIG. 9, according to an exemplary embodiment.

[0019] FIG. 15 is a view of the drawstring of FIG. 9 after a first serving step, according to an exemplary embodiment.

[0020] FIG. 16 is a detailed view of a center portion of the drawstring of FIG. 9 after a second serving step, according to an exemplary embodiment.

[0021] FIG. 17 is a right, rear perspective view of the cam assembly coupled with a limb assembly of the crossbow of FIG. 1 and coupled with the drawstring FIG. 9 in a released configuration, according to an exemplary embodiment.

[0022] FIG. 18 is a top view of the cam assembly coupled with the limb assembly of the crossbow of FIG. 1 and coupled with the drawstring FIG. 9 in the released configuration, according to an exemplary embodiment.

[0023] FIG. 19 is a right, rear view of the cam assembly coupled with the limb assembly of the crossbow of FIG. 1 and coupled with the drawstring FIG. 9 in a drawn configuration, according to an exemplary embodiment.

[0024] FIG. 20 is a top view of the cam assembly coupled with the limb assembly of the crossbow of FIG. 1 and coupled with the drawstring FIG. 9 in the drawn configuration, according to an exemplary embodiment.

[0025] FIG. 21 is a block diagram of a method of manufacturing the drawstring of FIG. 9, according to an exemplary embodiment.

[0026] FIG. 22 is a block diagram of a method of manufacturing the drawstring of FIG. 9, according to an exemplary embodiment.DETAILED DESCRIPTION

[0027] Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

[0028] Referring to FIGS. 1-5, a crossbow (e.g., bow, projectile launcher, etc.), shown as crossbow 100, is shown in a released configuration (e.g., de-cocked position, fired position, un-drawn position, etc.). According to an exemplary embodiment, the crossbow 100 includes a frame (e.g., rail, chassis, body, shell, or other frame member), shown as frame 102, a limb assembly 104 coupled to the frame 102 at a distal end 106 (e.g., front end, down-range end) of the crossbow 100, and a cam assembly 108 coupled to the limb assembly 104.

[0029] The frame102 includes a center rail 110 configured to support a projectile (e.g., an arrow, a bolt, etc.) when the crossbow 100 is loaded and guide the projectile during firing operations. A riser 112 is coupled to the frame 102 at the distal end 106 of the crossbow 100 and is configured to couple the limb assembly 104 to the frame 102. In some embodiments, the crossbow 100 includes a stock 114 coupled to the frame 102 at a proximal end 116 (e.g., rear end) of the crossbow 100. The stock 114 may provide a support surface for a user to facilitate stabilizing the crossbow 100 during firing operations. The stock 114 may be removably coupled to the frame 102 to facilitate interchangeability of the stock 114 (e.g., a first stock 114 may be replaced with a second stock 114 having a different shape or configuration than the first stock 114). In some embodiments, the crossbow 100 does not include the stock 114. In some embodiments, the stock 114 is integrally formed with the frame 102.

[0030] As shown in FIGS. 1, 3, and 5, the frame 102 includes a rest (e.g., support), shown as arrow rest 118, configured to support the projectile when the crossbow 100 is loaded and to guide the projectile during firing operations such that the projectile is suspended above the center rail 110 when the crossbow 100 is in a drawn (e.g., cocked) configuration. Generally, the arrow rest 118 supports an end of the projectile such that the projectile is pointed in a down-range direction (e.g., in a direction towards a target positioned down-range from the distal end 106 of the crossbow) such that when the crossbow 100 is fired, the projectile is propelled (e.g., shot, thrust, fired, etc.) from the crossbow 100 in a down-range direction along a projectile axis A (e.g., longitudinal centerline, flight path, etc.). The projectile axis A may be an axis defined by the frame 102, the center rail 110 of the frame 102, or some other portion of the crossbow 100. The projectile axis A is an axis along which the projectile is loaded into the crossbow 100 and along which the projectile travels during operation of the crossbow 100 as the crossbow 100 is fired (e.g., as the crossbow 100 or a drawstring of the crossbow 100 moves from the drawn configuration to the released configuration). The projectile axis A extends in a direction between the distal end 106 and the proximal end 116 of the crossbow 100 and is substantially parallel with the center rail 110.

[0031] In some embodiments, the frame 102 includes multiple portions (e.g., a left and a right side, multiple frame shells, a top portion and a bottom portion, or some other portions) that are fastened together to form the frame 102. In some embodiments, the frame 102 is divided into more than two sections that are removably coupled or may not be divided into any sections. In some embodiments, the frame 102 is provided as a single, integrally formed section or structure. For example, the center rail 110, the riser 112, and the stock 114 may be integrally formed together as a unitary structure. The frame 102 or one or more components thereof (e.g., the center rail 110, the riser 112) may include a plurality of apertures, pockets, recesses, or other voids throughout that reduce weight. In some embodiments, the frame 102 includes no apertures. The frame 102 can be constructed of materials including plastic, carbon fiber composite, fiber glass, polymeric materials, synthetic materials, wood, aluminum, or one or more other materials.

[0032] As shown in FIGS. 1 and 2, the frame 102 includes a string cover 120. The string cover 120 extends over the center rail 110 permitting movement of a string carrier 122 and a drawstring 124 in a space laterally bounded by the center rail 110 and the string cover 120. In some embodiments, the string cover 120 is at least partially transparent to assist the user in loading and unloading a projectile, and to monitor activities of the drawstring 124 and the string carrier 122. As shown in FIG. 1, the string cover 120 includes a plurality of apertures (e.g., holes, gaps, spaces, etc.), shown as cut-outs 126. In some embodiments, the string cover 120 includes no cut-outs 126. In another embodiment, some or all of the string cover 120 may be constructed from a transparent material. The cut-outs 126 may be configured (e.g., spaced, sized, oriented, positioned, etc.) along the string cover 120 such that a user is unable to place their fingers in the drawstring path (e.g., in the space defined by the center rail 110 and the string cover 120, along the projectile axis A, etc.). In some embodiments, the string cover 120 is integrally formed with the frame 102 (e.g., the center rail 110). In other embodiments, the string cover 120 is selectively removable from the frame 102. In other embodiments, the crossbow 100 does not include the string cover 120. In such embodiments, the drawstring 124 is positioned vertically above the center rail 110 and can be exposed or accessible from above.

[0033] The string carrier 122 is configured to translate along the center rail 110 between an extended position and a retracted position to facilitate transitioning the crossbow 100 between released and drawn configurations (e.g., cocking the crossbow 100, de-cocking the crossbow). For example, during cocking (e.g., drawing) operations the string carrier 122 translates (e.g., slides, moves, etc.) forward along the center rail 110 toward the riser 112 to engage the drawstring 124 while the crossbow 100 is in the released configuration. The string carrier 122 selectively may be selectively coupled to the drawstring 124 such that when the string carrier 122 is translated rearward along the center rail 110 toward the proximal end 116 of the crossbow 100, the crossbow 100 transitions from the released configuration to the drawn configuration. The drawstring 124 is in a drawn (e.g., cocked) position or configuration when the crossbow 100 is in the drawn configuration. The drawstring 124 is in a released (e.g., uncocked, undrawn) position or configuration when the crossbow 100 is in the released configuration.

[0034] As shown in FIGS. 1-4, the string cover 120 includes a mount (e.g., a rail, a tactical, picatinny, or weaver mounting rail, etc.), shown as scope mount 128. In some embodiments, the scope mount 128 is integrally formed on a top surface of the string cover 120. In other embodiments, the scope mount 128 is selectively removable from the string cover 120. The scope mount 128 includes a platform on which one or more accessories (e.g., sights, scopes, lasers, etc.), shown as scope 130, may be coupled to the crossbow 100. The scope mount 128 includes a plurality of protrusions and grooves that secure the scope 130 and / or one or more other accessories. In some embodiments, the scope 130 includes a reticle with gradations corresponding to the ballistic drop of projectiles of a particular weight. In some embodiments, the crossbow 100 includes a scope mount rail positioned partially over the center rail 110 via a cantilever arm, a platform that at least partially straddles the projectile axis A, or some other structure other than the string cover 120.

[0035] A grip 132 is positioned between the distal end 106 and the proximal end 116 of the crossbow 100 along a bottom surface of the frame 102. In some embodiments, the grip 132 is integrally formed with the frame 102. The grip 132 includes an opening for a user to rest or place a finger. The grip 132 can have one or more concave indentations that are generally ergonomic. The grip 132 provides a point of support for a user of the crossbow 100. The grip 132 can be held by the user's hand. In some embodiments, the grip 132 is a pistol style grip. In some embodiments, a trigger 134 is positioned in the opening of the grip 132. The trigger 134 may be operatively coupled to a firing mechanism and the string carrier 122 such that actuating the trigger 134 (e.g., pulling the trigger 134) disengages the string carrier 122 from the drawstring 124 to fire the crossbow 100 and the projectile downrange. In some embodiments, the trigger 134 is aesthetic (e.g., the trigger 134 does not engage a firing mechanism).

[0036] According to the exemplary embodiment shown in FIGS. 1-4, the frame 102 includes a mount (e.g., a rail, a tactical, picatinny, or weaver mounting rail, etc.), shown as bottom mount 136. In some embodiments, the bottom mount 136 is integrally formed on a bottom surface of the frame 102. In other embodiments, the bottom mount 136 is selectively removable from the frame 102. The bottom mount 136 includes a platform on which one or more accessories (e.g., grips, cocking handles, quivers, lasers, etc.) may be coupled to the crossbow 100. The platform may be substantially similar to the scope mount 128 in that the platform may include a plurality of protrusions and grooves that secure the one or more other accessories. As shown, a lower grip 138, a quiver 140, and a cocking handle 142 are coupled to the crossbow 100 by way of the bottom mount 136. In some embodiments, the lower grip 138 is integrally formed with a bottom surface of the frame 102.

[0037] As shown in FIGS. 1-5, the riser 112 is configured to couple the limb assembly 104 to the crossbow 100. The limb assembly 104 includes a right limb assembly 104a and a left limb assembly 104b. The crossbow includes components defined as “right” and “left”. The “right” and the “left” components are substantially similar and mirrored as discussed below. The right limb assembly 104a includes a right upper limb 150a (e.g., a first upper limb) and a right lower limb 150b (e.g., a first lower limb). The left limb assembly 104b includes a left upper limb 150c (e.g., a second upper limb) and a left lower limb 150d (e.g., a second lower limb). The right upper limb 150a, the right lower limb 150b, the left upper limb 150c, and the left lower limb 150d may be collectively hereinafter referred to as limbs 150. In other embodiments, the crossbow 100 can include only one limb per side (e.g., rather than an upper and lower limb per side). For example, the right limb assembly 104a can include only a single right limb and the left limb assembly 104b can include only a single left limb. In yet other embodiments, the crossbow 100 can include more than two (e.g., three, four, five, or some other number of) limbs per side. For example, the right limb assembly 104a can include four limbs and the left limb assembly 104b can include four limbs.

[0038] The riser 112 is configured to join one end of each of the right upper limb 150a, the right lower limb 150b, the left upper limb 150c, and the left lower limb 150d to the center rail 110. In the illustrated embodiment, the limbs 150 have a generally concave shape directed at least partially toward the projectile axis A of the center rail 110 and extend from the riser 112 in a direction toward the proximal end 116 of the crossbow 100, ending at free ends 152a, 152b, 152c, and 152d. The limbs 150 are formed from an elastically deformable material shaped to resiliently flex during cocking. Potential energy is stored in the limbs 150 as they flex. The material used to form the limbs 150, the construction of limbs 150, and the shape of limbs 150 are selected to allow the potential energy stored in limbs 150 to be rapidly released during firing.

[0039] The limb assembly 104 includes mounts (e.g., pivots, connectors, etc.), shown as pivot mounts 154a, 154b, 154c, and 154d, coupled to the proximate free ends 152a, 152b, 152c, and 152d of the right upper limb 150a, the right lower limb 150b, the left upper limb 150c, and the left lower limb 150d respectively. The pivot mounts 154 are configured to receive a pivot pin (e.g., axle, shaft, post, etc.), shown as pivot pin 156, to rotatably couple the cam assembly 108 to the limb assembly 104. A right pivot pin 156a is mounted at an upper end to a right upper pivot mount 154a and at a lower end to a right lower pivot mount 154b and extends across a gap formed between the right upper limb 150a and the right lower limb 150b. A right cam 160a (e.g., a first cam) included in the cam assembly 108 is mounted to right pivot pin 156a (e.g., received by the right pivot pin 156a) within the gap formed between the right upper limb 150a and the right lower limb 150b. In some embodiments, the right pivot pin 156a is an independent component from the right cam 160a such that the right pivot pin 156a is fastened to the right cam 160a. In this way, the right pivot pin 156a is detachably coupled to the right cam 160a. Because the right pivot pin 156a is detachably coupled to the right cam 160a, the right pivot pin 156a can include a chamfer, round, fillet, or other feature at an interface between the right pivot pin 156a and the right cam 160a or elsewhere on the right pivot pin 156a that can substantially prevent abrasion or wear of the drawstring 124 coupled to the right cam 160a. In other embodiments, the right pivot pin 156a is integrally formed with the right cam 160a. The right pivot pin 156a may be received by one or more bearings positioned within the right upper pivot mount 154a and the right lower pivot mount 154b such that the right pivot pin 156a and the right cam 160a are configured to rotate relative to the right limb assembly 104a. In some embodiments, the right pivot pin 156a is fixedly coupled to the right limb assembly 104a (e.g., fixed within the right upper pivot mount 154a and the right lower pivot mount 154b) such that the right cam 160a is configured to rotate about the right pivot pin 156a. In some embodiments, the crossbow 100 includes two or more right cams 160a or two or more left cams 160b. For example, two right cams 160a can be coupled to the right limb assembly 104a and can rotate about one or more right pivot pins 156a (e.g., a common pivot pin 156a or separate pivot pins 156a).

[0040] Similarly, a left pivot pin 156b is mounted at an upper end to a left upper pivot mount 154c and at a lower end to a left lower pivot mount 154d and extends across a gap between left upper limb 150c and left lower limb 150d. A left cam 160b (e.g., a second cam) included in the cam assembly 108 is mounted to the left pivot pin 156b (e.g., received by the left pivot pin 156b) within a gap formed between the left upper limb 150c and the left lower limb 150d. In some embodiments, the left pivot pin 156b is an independent component from the left cam 160b such that the left pivot pin 156b is fastened to the left cam 160b. In this way, the left pivot pin 156b is detachably coupled to the left cam 160b. Because the left pivot pin 156a is detachably coupled to the left cam 160b, the left pivot pin 156b can include a chamfer, round, fillet, or other feature at an interface between the left pivot pin 156b and the left cam 160b or elsewhere on the left pivot pin 156b that can substantially prevent abrasion or wear of the drawstring 124 coupled to the left cam 160b. In other embodiments, the left pivot pin 156b is integrally formed with the left cam 160b. The left pivot pin 156b may be received by one or more bearings positioned within the left upper pivot mount 154c and the left lower pivot mount 154d such that the left pivot pin 156b and the left cam 160b are configured to rotate relative to the left limb assembly 104b. In some embodiments, the left pivot pin 156b is fixedly coupled to the left limb assembly 104b (e.g., fixed within the left upper pivot mount 154c and the left lower pivot mount 154d) such that the left cam 160b is configured to rotate about the left pivot pin 156b.

[0041] As shown in FIGS. 5-8, the cam assembly 108 includes the right cam 160a and the left cam 160b that are rotatable about a right cam axis B (e.g., a first cam axis) and a left cam axis C (e.g., a second cam axis), respectively, within a rotation plane P. For example, the right cam 160a and the left cam 160b define a vertically centered horizontal plane that is co-planar with the rotation plane P. The rotation plane P extends in a lateral direction between the right cam 160a and the left cam 160b and in a longitudinal direction between the distal end 106 and the proximal end 116 of the crossbow 100. In some embodiments, the projectile axis A extends within the rotation plane P. For example, the rotation plane P is a substantially horizontal plane parallel to the extension of the center rail 110.

[0042] Referring particularly to FIGS. 7a and 7b, the right cam 160a has a substantially circular profile. An outer circumference of the right cam 160a includes two right drawstring journals, shown as right upper drawstring journal 164a and right lower drawstring journal 164b, sized to receive the drawstring 124 and direct the drawstring 124 in a direction towards the left cam 160b across the projectile axis A. The right upper drawstring journal 164a and the right lower drawstring journal 164b may be spaced (e.g., vertically offset) such that the right upper drawstring journal 164a is positioned directly vertically above the right lower drawstring journal 164b. For example, a center portion of the right cam 160a, shown as lip 168a, forms at least a portion of both the right upper drawstring journal 164a and the right lower drawstring journal 164b. As shown, the right upper drawstring journal 164a and the right lower drawstring journal 164b are substantially parallel (e.g., within 10° of parallel). In other embodiments, the right upper drawstring journal 164a and the right lower drawstring journal 164b are non-parallel.

[0043] The right cam 160a defines a width 170a between a top surface 171a of the right cam 160a and a bottom surface 171b of the right cam 160a. In some embodiments, the width 170a is between 0.25 inches and 0.5 inches (e.g., 0.315 inches, 0.275 inches, 0.4 inches, or some other width). In other embodiments, the width 170a is otherwise suitably sized (e.g., more than 0.5 inches, less than 0.25 inches, or some other dimension) to allow the right upper drawstring journal 164a and the right lower drawstring journal 164b to receive the drawstring 124.

[0044] The right cam 160a defines a distance 172a between a center point of the right upper drawstring journal 164a and a center point of the right lower drawstring journal 164b. In some embodiments, the distance 172a is between 0.1 inches and 0.2 inches (e.g., 0.135 inches, 0.15 inches, or some other distance). In other embodiments, the distance 172a is otherwise suitably dimensioned (e.g., more than 0.2 inches, less than 0.1 inches, or some other dimension).

[0045] The right upper drawstring journal 164a and the right lower drawstring journal 164b define a radius 174a, a radial depth 176a, and an angle of separation 178a sized to receive the drawstring 124. In some embodiments, the radius 174a defined by the right upper drawstring journal 164a and the right lower drawstring journal 164b is equal to a radius of the drawstring 124. In other embodiments, the radius 174a is greater than the radius of the drawstring. In some embodiments, the radius 174a is between 0.05 inches and 0.1 inches (e.g., 0.09 inches, 0.075 inches, or some other dimension). In some embodiments, the radial depth 176a is between 0.1 inches and 0.2 inches (e.g., 0.178 inches, 0.15 inches, or some other dimension). In some embodiments, the angle of separation 178a is between 5 degrees and 7 degrees (e.g., 6.176 degrees, 6 degrees, or some other angle). In other embodiments, the radius 174a, the radial depth 176a, and / or the angle of separation 178a are otherwise suitably dimensioned.

[0046] The right cam 160a includes a right drawstring attachment post 180a (e.g., an anchor, a mounting point) positioned along the outer circumference of the right cam 160a and extends radially from the right cam 160a. In some embodiments, the right drawstring attachment post 180a is vertically centered on an outer radial surface (e.g., an outer circumference) of the right cam 160a within the rotation plane P. The right drawstring attachment post 180a is configured to couple a right end portion (e.g., a right end portion 266 as discussed below, a terminal portion, a looped end, an outermost portion, or some other end portion) of the drawstring 124 to the right cam 160a and is sized and shaped to maintain (e.g., hold, secure) the right end portion of the drawstring 124 around the right drawstring attachment post 180a when the crossbow 100 is in the drawn configuration and the released configuration. For example, the right drawstring attachment post 180a may include a groove sized to maintain the right end portion of the drawstring 124 around the right drawstring attachment post 180a when the crossbow 100 is in the drawn configuration and the released configuration. The right drawstring attachment post 180a is configured to vertically space the drawstring 124 such that the drawstring 124 is directed in a direction toward and received within the right upper drawstring journal 164a and the right lower drawstring journal 164b. In some embodiments, the right drawstring attachment post 180a is an independent component from the right cam 160a such that the right drawstring attachment post 180a is fastened to the right cam 160a. In this way, the right drawstring attachment post 180a is detachably coupled to the right cam 160a. In other embodiments, the right drawstring attachment post 180a is integrally formed with the right cam 160a.

[0047] Referring still to FIGS. 7a and 7b, the right cam 160a includes at least one cable guide 184. As shown, the right cam 160a includes a right upper cable guide 184a (e.g., a first upper cable guide) and a right lower cable guide 184b (e.g., a first lower cable guide). The right upper cable guide 184a and the right lower cable guide 184b each include a journal 186 (e.g., helical journal, spiral journal, a journal having a three-dimensional curvature or path) sized to receive, take-up, let-out, or otherwise engage with at least one power cable (e.g., a power cable 250 as discussed below). The right upper cable guide 184a extends in an upward vertical direction (e.g., substantially perpendicular to) from the top surface 171a of the right cam 160a. Similarly, the right lower cable guide 184b extends in a downward vertical direction (e.g., substantially perpendicular to) from the bottom surface 171b of the right cam 160a. For example, the right upper cable guide 184a and the right lower cable guide 184b extend from the top surface 171a and the bottom surface 171b of the right cam 160a such that the right upper drawstring journal 164a and the right lower drawstring journal 164b are positioned between the right upper cable guide 184a and the right lower cable guide 184b. The right upper cable guide 184a and the right lower cable guide 184b may extend along the right cam axis B. The right cam 160a includes an aperture (e.g., hole, opening, passageway) through which the right pivot pin 156a extends such that the right cam 160a and the right pivot pin 156a are coaxial with and rotate about the right cam axis B when the crossbow 100 is transitioned between the drawn and released configurations. In some embodiments, the journal 186 (e.g., path, groove, slot, notch, or other feature) of the right upper cable guide 184a and the right lower cable guide 184b have the same radius 174a, radial depth 176a, and / or angle of separation 178a as the right upper drawstring journal 164a and the right lower drawstring journal 164b. In other embodiments, the journal 186 is otherwise suitably dimensioned to receive a power cable. In some embodiments, the right cam 160a includes two cable guides, three cable guides, four cable guides, or some other number of cable guides. For example, the right cam 160a can include more than one right upper cable guide 184a, more than one right lower cable guide 184b, or some other cable guide configured to receive, take-up, let-out, or otherwise engage with a power cable. In some embodiments, each cable guide 184 can engage with two or more power cables.

[0048] The right cam 160a includes a right upper power cable post 188a (e.g., an anchor, a mounting point) positioned on the top surface 171a of the right cam 160a that extends in a substantially upward vertical direction from the right cam 160a. The right cam 160a includes a right lower power cable post 188b (e.g., an anchor, a mounting point) positioned on the bottom surface 171b of the right cam 160a that extends in a substantially downward vertical direction from the right cam 160a. The right upper power cable post 188a and the right lower power cable post 188b are configured to couple an end portion (e.g., a terminal portion, a looped end, an outermost portion, or some other end portion) of a power cable (e.g., the power cable 250) to the right cam 160a and is sized and shaped to maintain (e.g., hold, secure) the respective end portion of the power cable around the right upper power cable post 188a or the right lower power cable post 188b when the crossbow 100 is in the drawn configuration and the released configuration. For example, the right upper power cable post 188a and the right lower power cable post 188b may include a groove sized to maintain an end portion (e.g., a terminal portion, a looped end, outermost portion, or other end portion) of a power cable around the right upper power cable post 188a and the right lower power cable post 188b when the crossbow 100 is in the drawn configuration and the released configuration. The right cam 160a can include two power cable posts, three power cable posts, four power cable posts, or some other number of power cable posts. For example, the right cam 160a can include at least one power cable post per cable end portion that is coupled to the right cam 160a. The right cam 160a can include more than one power cable posts per power cable end portion that is coupled to the right cam 160a.

[0049] The right cam 160a defines a height 190a between a top surface of the right upper cable guide 184a and a bottom surface of the right lower cable guide 184b. In some embodiments, the height 190a is between 1 inch and 1.5 inches (e.g., 1.32 inches, 1.25 inches, or some other height). In other embodiments, the height 190a is otherwise suitably sized (e.g., more than 1.5 inches, less than 1 inch, or some other height) to accommodate the right upper cable guide 184a and the right lower cable guide 184b receiving a power cable.

[0050] According to an exemplary embodiment, the right cam 160a includes a plurality of apertures, holes, openings, etc. positioned throughout the right cam 160a to reduce the weight of the right cam 160a. In some embodiments, the right cam 160a includes more or fewer apertures than shown in FIG. 7a. In other embodiments, the right cam 160a does not include any apertures to reduce the weight.

[0051] Referring to FIGS. 8a and 8b, the left cam 160b is substantially similar and operates similarly to the right cam 160a and can be considered a mirror image of the right cam 160a. The left cam 160b includes a left upper drawstring journal 164c and a left lower drawstring journal 164d defining a width 170b, an upper surface 171c, a bottom surface 171d, a distance 172b, a radius 174b, a radial depth 176b, and an angle of separation 178b; a lip 168b; a left drawstring attachment post 180b; a left upper cable guide 184c (e.g., a second upper cable guide) and a left lower cable guide 184d (e.g., a second lower cable guide) defining a height 190b; and a left upper power cable post 188c and a left lower power cable post 188d.

[0052] Referring to FIG. 9, the drawstring 124 is shown, according to an exemplary embodiment. The drawstring 124 includes a center portion 200, a left loop portion 204 that forms a loop (e.g., a hoop, a closed curve) left of the center portion 200 of the drawstring 124, and a right loop portion 208 that forms a loop (e.g., a hoop, a closed curve) right of the center portion 200 of the drawstring 124. It should be understood that the terms “center,”“left,” and “right” are merely used to describe the orientation of various elements in the FIGURES. In other words, the terms “center,”“left,” and “right” used herein are for the purpose of description only and should not be regarded as limiting.

[0053] The center portion 200 may be a connecting portion of the drawstring 124 that connects the left loop portion 204 and the right loop portion 208 to each other. In other words, the center portion 200 is positioned laterally between the left loop portion 204 and the right loop portion 208 such that the left loop portion 204 and the right loop portion 208 are spaced apart from each other. Generally, the left loop portion 204 engages with the left cam 160b and is received within the left upper drawstring journal 164c and the left lower drawstring journal 164d, the right loop portion 208 engages with the right cam 160a and is received within the right upper drawstring journal 164a and the right lower drawstring journal 164b. The center portion 200 of the drawstring 124 extends in a lateral direction across the center rail 110 from the left cam 160b to the right cam 160a. The center portion 200 provides a section of the drawstring 124 to nock (e.g., selectively couple, load) the projectile thereto. For example, during operation of the crossbow 100 after the drawstring 124 is in a drawn (e.g., cocked) position, a user can provide the nock of a projectile over a length (e.g., a portion, an area, a region, a segment) of the center portion 200 such that the nock of the projectile is removably coupled to the center portion 200 of the drawstring 124. As the drawstring 124 moves from the drawn (e.g., cocked) position to the released (e.g., uncocked, undrawn) position and ultimately reaches the released position, the nock will separate from the center portion 200 of the drawstring 124 and the projectile will travel from the distal end 106 of the crossbow 100 (e.g., in a down-range direction toward a target).

[0054] Referring to FIGS. 10A and 10B, the drawstring 124 (e.g., the center portion 200, the left loop portion 204, the right loop portion 208) may be manufactured from a plurality of strings (e.g., strands, fibers, ropes, yarn), shown as inner strings 212. In some embodiments, the drawstring 124 is manufactured from a number of inner strings 212 that is between 10 and 22. In other embodiments, the drawstring 124 is manufactured from fewer than 10 inner strings 212 (e.g., 9 inner strings 212, 7 inner strings 212, 5 inner strings 212, or some other number of inner strings 212) or more than 22 inner strings 212 (e.g., 23 inner strings 212, 25 inner strings 212, 27 inner strings 212, or some other number of inner strings 212). Each inner string 212 has a diameter. Each inner string 212 of the drawstring 124 can include a substantially identical diameter. In other embodiments, the inner strings 212 of the drawstring 124 include two or more different diameters. Further, the diameter of each inner string 212 can remain substantially (e.g., ±95%) continuous over a length of the inner string 212 (e.g., from end to end). In other embodiments, the diameter of each inner string 212 can vary over a length of the inner string 212 (e.g., have a thicker portion and a thinner portion). The number of inner strings 212 may affect the thickness (e.g., diameter) of the drawstring 124. For example, manufacturing the drawstring 124 from a smaller number of inner strings 212 may reduce the thickness of the drawstring 124. The number of inner strings 212 may affect the strength (e.g., deformation resistance, tensile strength, elasticity) of the drawstring 124. For example, manufacturing the drawstring 124 from a larger number of inner strings 212 may increase the strength of the drawstring 124. Further, the diameter of inner strings 212 can affect the thickness (e.g., diameter), strength, or flexibility of the drawstring 124.

[0055] As shown in FIG. 10A, the inner strings 212 are not twisted, but instead form a bundle of inner strings 212 that are substantially aligned in an axial direction. For example, each of the inner strings 212 includes an axis, shown as string axis S, that can be substantially parallel (e.g., ±15° from parallel) with string axes S of each of the other inner strings 212. In particular, before the opposing ends of the inner strings 212 are joined together to create a continuous loop 220 as is discussed in detail below with reference to FIG. 11, among others, each of the inner strings 212 can be a substantially longitudinal string having a string axis S that is substantially parallel to the string axes S of each of the other inner strings 212. When the opposing ends of the inner strings 212 are joined together to form a continuous loop 220, as discussed below with reference to FIG. 11, each individual inner string 212 can extend along a path that is substantially identical in size and shape to paths along which all other inner strings 212 extend. In various embodiments, the inner strings 212 are substantially aligned and not twisted relative to each other or relative to some common axis. For example, the group of inner strings 212 can include an axis (e.g., a central axis running through the entire bundle of inner strings 212, a central axis of the drawstring 124), shown as common axis CA. Likewise, the group of inner strings 212 can extend along a path (e.g., a circular path, an ovular path, a curvilinear path). Each of the individual inner strings 212 of the group of inner strings 212 can have an individual string axis S that is substantially aligned (e.g., substantially parallel) with the common axis CA of the group of inner strings 212. Likewise, each of the individual inner strings 212 extends along a path that is substantially aligned (e.g., substantially identical in size and shape) with the path along which the entire group of inner strings 212 extends. The group of substantially aligned inner strings 212 (e.g., parallel string axes S, extending along a substantially identical shape) collectively form the core 216.

[0056] As shown in FIG. 10B, the inner strings 212 are twisted (e.g., rotated about an axis, coiled around common axis CA, strand twisted, wound, wrapped, plied, etc.) to collectively form a core 216 of the drawstring 124. For example, “twisting” may refer to the inner strings 212 being collectively (e.g., as a bundle or group of inner strings 212) twisted around a central axis of the drawstring 124 (e.g., an axis running axially through a center of the drawstring 124) or the common axis CA of the core 216. More specifically, the inner strings 212 can be twisted helically or according to some other three-dimensional path about a central axis of the drawstring 124. Likewise, the inner strings 212 can be twisted such that the string axis S of each of the inner strings 212 wrap around the common axis CA of the group of inner strings 212 (e.g., around the common axis CA of the core 216) along the length of the core 216. By way of another example, “twisting” may refer to the inner strings 212 being wrapped around each another in a specific pattern (e.g., braided, plied, or some other pattern). In some embodiments, the inner strings 212 are twisted between 7 and 12 twists per foot of core 216. For example, if the length of the core 216 is four feet long, the inner strings 212 may be twisted between 28 and 48 times (e.g., between 28 and 48 revolutions, cycles, twists, etc.). In some embodiments, the inner strings 212 are twisted less than 7 twists per foot (e.g., 6 twists per foot, 5 twists per foot, etc.) or more than 12 twists per foot (e.g., 13 twists per foot, 15 twists per foot, etc.). In some embodiments, to twist the inner strings 212 and form the core 216, a first end of each inner string 212 (e.g., the first end of all inner strings 212 within the core 216) may be held in place while second ends of each inner string 212 (e.g., the second end of all inner strings 212 within the core) are twisted around each other. In some embodiments, one twist is equivalent to one 360° revolution of the second ends of each inner string 212 around a central axis (e.g., a central axis of the core 216 or a central axis of the drawstring 124). The length of each inner string 212 may be substantially similar. In some embodiments, before twisting the inner strings 212 to form the core 216, the inner strings 212 are equally pre-tensioned such that each inner string 212 experiences a substantially similar tension when the drawstring 124 is installed on the crossbow 100 and when the crossbow 100 is in the released configuration, the drawn configuration, and / or any position or configuration therebetween. In such embodiments, the tension applied to the inner strings 212 may affect a torsional force condition (e.g., a torsional bias) between the left loop portion 204 and the right loop portion 208. For example, a decreased tension applied to the inner strings 212 during the formation of the core 216 (e.g., while twisting the inner strings 212. may decrease the induced torsional bias on the drawstring 124. In other embodiments, the inner strings 212 are otherwise joined together to form the core 216. For example, the inner strings 212 may be arranged twisting around each other or twisting around a common axis.

[0057] Referring to FIG. 11, after grouping the inner strings 212 together to form the core 216 (e.g., by twisting the inner strings 212 as shown in FIG. 10B or leaving the inner strings 212 untwisted as shown in FIG. 10A), opposite ends of the core 216 may be joined such that the core 216 forms a continuous loop 220. In some embodiments, the opposite ends of the core 216 are tied (e.g., knotted) together to form the continuous loop 220. In other embodiments, the opposite ends of the core 216 are spliced (e.g. interwoven) together to form the continuous loop 220. In yet other embodiments, the opposite ends of the core 216 are joined together to form the continuous loop 220 by way of another method, such as via some adhesive, some melting or fusing process, or some other process. In some embodiments, the opposite ends of the core 216 that are joined together are served (e.g., circumferentially wrapped by a serving material) to ensure the continuous loop 220 is not come un-done (e.g., the opposite ends of the core 216 separate).

[0058] Referring to FIG. 12, after joining opposite ends of the core 216 to form the continuous loop 220, the continuous loop 220 may be twisted such that a center section (e.g., center portion 200) of the continuous loop 220 is twisted and the left and right sides of the continuous loop 220 form separate loops (e.g., left loop portion 204 and right loop portion 208). For example, a first portion of the continuous loop 220 (e.g., a left-most portion) and a second portion of the continuous loop 220 (e.g., a right-most portion) can rotate about an axis relative to each other (e.g., in opposite directions) such that the remaining portions of the continuous loop 220 (e.g., portions of the continuous loop 220 between the first portion and the second portion) are twisted about an axis. In some embodiments, the continuous loop 220 is twisted between 7 and 12 twists per foot. In other embodiments, the continuous loop 220 is twisted less than 7 twists per foot (e.g., 6 twists per foot, 5 twists per foot, etc.) or more than 12 twists per foot (e.g., 13 twists per foot, 15 twists per foot, etc.). The continuous loop 220 may be twisted such that the center portion 200 is substantially centered between the left end portion (e.g., left end portion 270, terminal portion, looped end, outermost portion, or other end portion) of the left loop portion 204 and the right end portion (e.g., right end portion 266, terminal portion, looped end, outermost portion, or other end portion) of the right loop portion 208. The twisted center portion 200 may be formed when the left and right sides of the continuous loop 220 are twisted. For example, and as shown in FIG. 12, the left side of the continuous loop 220 is twisted clockwise (when viewed from a left side view), and the right side of the continuous loop 220 is twisted clockwise (when viewed from a right side view) to form the center portion 200. In other embodiments, the left side of the continuous loop 220 is twisted counterclockwise (when viewed from a left side view), and the right side of the continuous loop 220 is twisted counterclockwise (when viewed from a right side view) to form the center portion 200. In some embodiments, after joining opposite ends of the core 216 to form the continuous loop 220, the continuous loop 220 can remain untwisted. Put another way, the continuous loop 220 need not be subject to any twisting process or operation. In such embodiments, the step of forming the drawstring 124 shown in FIG. 12 may be omitted such that the center portion 200, the left loop portion 204, and the right loop portion 208 of the untwisted drawstring 124 shown in FIG. 11 are served (discussed below with reference to FIGS. 13-15) in a first serving process and a second serving process.

[0059] Referring to FIG. 13, at least a portion of the center portion 200, the left loop portion 204, and the right loop portion 208 are served (e.g., bound, wrapped, etc.) with a serving material (e.g., strand, fiber, rope, yarn, etc.), shown as serving material 224. The serving material 224 may be made from a material such as polyester, high-strength synthetic fibers, high modulus polyethylene, nylon, etc. In other embodiments, the serving material 224 is made from any other suitable material capable of resisting large and repeated tensions, repeated abrasions, moisture, creep, deformation, etc. The process of serving may include circumferentially wrapping the serving material 224 around an outer surface of the continuous loop 220 (e.g., around the center portion 200, the left loop portion 204, and the right loop portion 208). In some embodiments, the serving material 224 (or a spool holding the serving material 224) is tensioned when the serving material 224 is served around the core 216. In such embodiments, the tension applied to the serving material 224 may affect a torsional force condition (e.g., a torsional bias) between the left loop portion 204 and the right loop portion 208. For example, a decreased tension applied to the serving material 224 during the serving of the core 216 (e.g., while wrapping the serving material 224 around the center portion 200, the left loop portion 204, and the right loop portion 208) may decrease the induced torsional bias on the drawstring 124. After serving, the serving material 224 may substantially cover (e.g., surround, encompass, envelop, etc.) the inner strings 212 comprising the continuous loop 220 (e.g., the core 216).

[0060] According to an exemplary embodiment shown in FIG. 13, the serving material 224 is served around at least a portion of the left loop portion 204 and around at least a portion of the right loop portion 208. The serving material 224 may be served in a first serving direction, shown as first direction 228, and / or in a second serving direction, shown as second direction 232, opposite the first direction 228 around the left loop portion 204 and the right loop portion 208. For example, and as shown in FIG. 13, the left loop portion 204 may be served using the serving material 224 starting at a location proximate the center portion 200, serving in the first direction 228 around the left loop portion 204, and ending at a location proximate the center portion 200. In such an example, the right loop portion 208 may be served using the serving material 224 starting at a location proximate the center portion 200, serving in the second direction 232 around the right loop portion 208, and ending at a location proximate the center portion 200. The left loop portion 204 and the right loop portion 208 are served independently. The first direction 228 in which the serving material 224 is served around the left loop portion 204 may be different (e.g., opposite) the second direction 232 in which the serving material 224 is served around the right loop portion 208. For example, the serving material 224 may be served in a clockwise direction (e.g., the first direction 228) around the left loop portion 204, and the serving material 224 may be served in a counterclockwise direction (e.g., the second direction 232) around the right loop portion 208. By way of another example, the serving material 224 may be served in a counterclockwise direction (e.g., the first direction 228) around the left loop portion 204, and the serving material 224 may be served in a clockwise direction (e.g., the second direction 232) around the right loop portion 208. In some embodiments, a girth hitch knot (e.g., a strap hitch, bale sling hitch, ring hitch) may be located between the left loop portion 204 and the right loop portion 208. For example, a girth hitch knot can be used to alter the serving direction such that the left loop portion 204 can be served in a direction that is opposite a direction that the right loop portion 208 is served while using a continuous strand (e.g., section, piece, etc.) of the serving material 224. The girth hitch knot can be positioned at a center of the center portion 200. In other embodiments, the girth hitch knot is positioned off-center of the center portion 200 (e.g., within less 10 mm to one side of the center of the center portion 200 or more than 10 mm to one side of the center of the center portion 200).

[0061] According to an exemplary embodiment shown in FIGS. 14 and 15, the serving material 224 is served around the core 216 prior to or without twisting the continuous loop 220 such that the center portion 200 is twisted. In other words, the serving material 224 served around the left loop portion 204 and the right loop portion 208 as shown in FIGS. 14 and 15 is served around the core 216 of the drawstring 124 shown in FIG. 11. As shown in FIGS. 14 and 15, the drawstring 124 is arranged such that the left loop portion 204 and the right loop portion 208 are substantially parallel with each other. During the serving process, the drawstring 124 may be arranged in this manner such that the serving material 224 is served around portions of the core 216 that are substantially straight (e.g., flat, not curved) and the center portion 200 is curved (e.g., not straight). For example, the left loop portion 204 and the right loop portion 208 are straight and substantially parallel with each other such that the serving material 224 is not served around the left loop portion 204 and the right loop portion 208 when the left loop portion 204 and the right loop portion 208 are curved (e.g., as shown in FIG. 12), and is rather served around the left loop portion 204 and the right loop portion 208 when the left loop portion 204 and the right loop portion 208 are substantially straight.

[0062] As shown in FIGS. 14 and 15, the serving material 224 is served around at least a portion of the left loop portion 204 and served around at least a portion of the right loop portion 208, such that the left loop portion 204 and the right loop portion 208 include portions (e.g., sections, lengths) that are unserved (e.g., not served with the serving material 224). As shown in FIGS. 14 and 15, the serving material 224 is served around a first served portion (e.g., a portion of the left upper portion 204a), a second served portion (e.g., a portion of the left end portion 270), and a third served portion (e.g., a portion of the left lower portion 204b) of the left loop portion 204, and served around a first served portion (e.g., a portion of the right upper portion 208a), a second served portion (e.g., a portion of the right end portion 266), and a third served portion (e.g., a portion of the right lower portion 208b) of the right loop portion 208. The left loop portion 204 includes a first unserved portion between the first served portion and the second served portion, and a second unserved portion between the second served portion and the third served portion. Similarly, the right loop portion 208 includes a first unserved portion between the first served portion and the second served portion, and a second unserved portion between the second served portion and the third served portion. In some embodiments, the left loop portion 204 and the right loop portion 208 (e.g., the various portions thereof) are served with the serving material 224 in one or more of the first direction 228 or the second direction 232. For example, as shown in FIG. 14, the first served portion of the left loop portion 204 may be served in the first direction 228, the second served portion of the left loop portion 204 may be served in the second direction 232, and the third served portion of the left loop portion 204 may be served in the second direction 232. Similarly, as shown in FIG. 14, the first served portion of the right loop portion 208 may be served in the second direction 232, the second served portion of the right loop portion 208 may be served in the first direction 228, and the third served portion of the right loop portion 208 may be served in the first direction 228. By way of another example, the various portions of the left loop portion 204 and the right loop portion 208 may be served in another combination of serving directions to maintain a neutrally balanced string assembly.

[0063] Referring to FIGS. 14 and 15, the seams (e.g., points) at which the serving material 224 starts or stops being applied to the left loop portion 204 and the right loop portion 208 are shown as serving ends 236. As shown in FIGS. 14 and 15, the left end portion 270 of the left loop portion 204 and the right end portion 266 of the right loop portion 208 are served with the serving material 224 such that the entirety of the left end portion 270 and the right end portion 266 are served (e.g., covered with the serving material 224). In other words, the left end portion 270 is served such that when the drawstring 124 is installed on the crossbow 100, the serving ends 236 of the serving around the left end portion 270 are not inline (e.g., not engaged) with the left drawstring attachment post 180b. Similarly, the right end portion 266 is served such that when the drawstring 124 is installed on the crossbow 100, the serving ends 236 of the serving around the right end portion 266 are not inline (e.g., not engaged) with the right drawstring attachment post 180a. For example, the left end portion 270 and the right end portion 266 may be served with the serving material 224 such that the serving ends 236 do not engage with the right drawstring attachment post 180a or the left drawstring attachment post 180b when the drawstring 124 is installed on the crossbow 100. If the serving ends 236 were to engage with the drawstring attachment posts 180, the rotation of the right cam 160a and the left cam 160b during operation of the crossbow 100 may cause damage to the drawstring 124 (e.g., the serving material 224, the inner strings 212 forming the core 216).

[0064] When serving a core of a bowstring (e.g., a drawstring, a power cable, etc.), a bias (e.g., a rotational biasing force, a torsional force) can be created within the bowstring that biases the bowstring in the direction that the core was served. For example, a bowstring may have a tendency to want to twist (e.g., rotate) in a particular direction, giving the bowstring a preloaded twisted form. By wrapping the serving material 224 around the left loop portion 204 and the right loop portion 208 in opposite directions, a material bias of both the left loop portion 204 and the right loop portion 208 can be in a direction towards the center portion 200 of the drawstring 124, such that any bias (e.g., torsional bias, rotational bias) in the left loop portion 204 created during the serving process counteracts any bias (e.g., torsional bias, rotational bias) in the right loop portion 208 created during the serving process, and vice versa. For example, serving the left loop portion 204 and the right loop portion 208 in opposing directions facilitates a construction of the drawstring 124 having substantially no rotational bias one direction or another. By way of another example, serving (i) a first portion of the left loop portion 204 and a second portion of the left loop portion 204 in opposing directions, and (ii) a first portion of the right loop portion 208 and a second portion of the right loop portion 208 in opposing directions facilitates a construction of the drawstring 124 having substantially no rotational bias one direction or another (e.g., to maintain a neutrally balanced drawstring assembly). In other words, the left loop portion 204 may include a first torsional bias force with a first magnitude and the right loop portion may include a second torsional bias force with a second magnitude that is substantially equal to the first magnitude of the first torsional bias force.

[0065] In some embodiments, the serving material 224 may be served in the first direction 228 around at least a portion of the left loop portion 204 such that the first direction 228 is opposite a direction that the inner strings 212 were twisted to form the core 216. Similarly, the serving material 224 may be served in the second direction 232 around at least a portion of the right loop portion 208 such that the second direction 232 is opposite a direction that the inner strings 212 were twisted to form the core 216. In this manner, serving the left loop portion 204 and the right loop portion 208 in directions that oppose the direction that the inner strings 212 were twisted to form the core 216 counteracts a bias (e.g., torsional bias, rotational bias) formed in the core 216 as a result of twisting the inner strings 212.

[0066] As shown in FIG. 16, after serving one or more portions of the left loop portion 204 and the right loop portion 208 (as discussed above with reference to FIGS. 13-15), the center portion 200 may be served using the serving material 224. As shown in FIG. 16, the drawstring 124 is rotated (e.g., about 90 degrees counterclockwise) after serving one or more portions of the left loop portion 204 and the right loop portion 208 and prior to serving the center portion 200. As such, the top and bottom portions of the center portion 200 are substantially straight (e.g., parallel with each other), and the left loop portion 204 and the right loop portion 208 are curved (e.g., arced, looped) to form left and right loops, respectively. In some embodiments, the serving material 224 used to serve the center portion 200 may at least partially overlap the serving material 224 used to serve the left loop portion 204 and the right loop portion 208. For example, the servings of the center portion 200 may overlap the servings of the left loop portion 204 and the right loop portion 208 by 0.1 inches to 0.25 inches. In other embodiments, the serving of the center portion 200 may overlap the servings of the left loop portion 204 and the right loop portion 208 by less than 0.1 inches (e.g., 0.075 inches, 0.05 inches, etc.) or more than 0.25 inches (e.g., 0.3 inches, 0.5 inches, etc.). In yet other embodiments, the serving of the center portion 200 and the servings of the left loop portion 204 and the right loop portion 208 may not overlap. For example, the center portion 200 may include a first served portion 200a and a second unserved portion 200b positioned (i) between the left loop portion 204 and the first served portion 200a and (ii) between the right loop portion 208 and the first served portion 200a. In such an example, the first served portion 200a may be about 3 inches (e.g., about 3.1 inches, about 3.2 inches, more than 3 inches, about 2.9 inches, about 2.8 inches, less than 3 inches, etc.) and the second unserved portion 200b may be about 1.375 inches (e.g., about 1.4 inches, more than 1.375 inches, about 1.35 inches, less than 1.375 inches, etc.). In some embodiments, after serving the one or more portions of the left loop portion 204 and the right loop portion 208 and prior to serving the center portion 200, the drawstring 124 my be twisted one or more times such that the continuous loop 220 is twisted and the left and right sides of the continuous loop 220 form separate loops (e.g., the left loop portion 204 and the right loop portion 208). For example, a first portion of the continuous loop 220 (e.g., a left-most portion) and a second portion of the continuous loop 220 (e.g., a right-most portion) can rotate about an axis relative to each other (e.g., in opposite directions) such that the remaining portions of the continuous loop 220 (e.g., portions of the continuous loop 220 between the first portion and the second portion) are twisted about an axis. In such embodiments, the twisted portion of the center portion 200 may be served with the serving material 224. In other embodiments, the center portion 200 is not twisted prior to being served.

[0067] According to an exemplary embodiment, the first served portion 200a of the center portion 200 is served such that the drawstring 124 has substantially no rotational bias one direction or another. For example, a left side of the center portion 200 may be served in a direction that is opposite a direction that a right side of the center portion 200 is served. For example, a girth hitch may be located substantially centered (e.g., within 10 mm of center) in a lateral direction along the center portion 200 such that the left side of the center portion 200 is served in a direction that is opposite a direction that the right side of the center portion 200 is served. In some embodiments, serving the left side and the right side of the center portion 200 in opposing directions facilitates a construction of the drawstring 124 (and the center portion 200) having substantially no bias (e.g., torsional bias, rotational bias) one direction or another. For example, the drawstring 124 can be substantially balanced so as to provide a neutral torsional force condition with substantially no torsional bias (e.g., a counteracting torsional bias) between the left loop portion 204 and the right loop portion 208. In some embodiments, the center portion 200 is served entirely in a single direction, thereby creating a bias (e.g., torsional bias, rotational bias) in the serving direction within the center portion 200. In such embodiments, the direction of the bias (e.g., torsional bias, rotational bias) is the same as a direction that the projectile launched from the crossbow 100 (e.g., a projectile nocked to the center portion 200 of the drawstring 124 and fired from the crossbow 100) has a tendency to rotate when launched (e.g., thrust, propelled, fired, released) from the crossbow 100. For example, the projectile launched from the crossbow 100 can include fletching (e.g., one or more vanes, feathers, or other stabilizing attachments) that cause the projectile rotate about a longitudinal axis of the projectile as the projectile is launched from the crossbow 100. In such embodiments, the center portion 200 can be served entirely in a single direction such that the direction of a bias (e.g., a torsional bias, a rotational bias) of the center portion 200 is substantially the same direction as the direction in which the projectile has a tendency to rotate after the projectile is launched from the crossbow 100.

[0068] In some embodiments, the type serving material 224 used to serve the left loop portion 204 and the right loop portion 208 may be different than the type of serving material 224 used to serve the center portion 200. For example, the type serving material 224 used to serve the left loop portion 204 and the right loop portion 208 may be an ultra-high-molecular-weight polyethylene serving having a 0.014 inch diameter. In other embodiments, the type serving material 224 used to serve the left loop portion 204 and the right loop portion 208 is of another suitable type having suitable dimensions. By way of another example, the type serving material 224 used to serve the center portion 200 may be a high modulus polyethylene serving having a 0.026 serving. In other embodiments, the type serving material 224 used to serve the center portion 200 is of another suitable type having suitable dimensions. In some embodiments, a portion of the drawstring 124 that does not contact (e.g., interface, rub, touch, engage with) any component of the crossbow 100 (e.g., a nock of a projectile, a drawstring journal 164, a drawstring attachment post 180, etc.) may not be served. In some embodiments, the type serving material 224 used to serve the left loop portion 204 and the right loop portion 208 is chosen such that an outer diameter of the left loop portion 204 and the right loop portion 208 is equal to or less than the radius 174 of the drawstring journal 164 (e.g., such that the left loop portion 204 and the right loop portion 208 can be received within the drawstring journals 164). In some embodiments, the type serving material 224 used to serve the center portion 200 is chosen such that an outer diameter of the center portion 200 can be received within a nock of the projectile.

[0069] As shown in FIGS. 5, 6, and 17-20, the drawstring 124 and power cables 250 are installed on the crossbow 100. Specifically, the crossbow 100 includes four power cables 250, including a first power cable 250a, a second power cable 250b, a third power cable 250c, and a fourth power cable 250d, with each one corresponding to a respective cable guide 184. In embodiments where the crossbow 100 has greater or fewer cable guides 184, the crossbow 100 can include correspondingly greater or fewer power cables 250. For example, the crossbow 100 may include one cable guide 184 and, correspondingly, one power cable 250. By way of another example, the crossbow 100 may include two cable guides 184 (e.g., a top cable guide 184 and a bottom cable guide 184) and, correspondingly, two power cables 250 (e.g., a top power cable 250 and a bottom power cable 250). Each power cable 250 includes a first end portion 254a, 254b, 254c, and 254d (e.g., terminal portion, looped end, outermost portion, or other end portion) that is configured to be coupled to (e.g., wrapped around, mounted at, etc.) the right cam 160a or the left cam 160b at right upper power cable post 188a, right lower power cable post 188b, left upper power cable post 188c, and left lower power cable post 188d, respectively. The right upper cable guide 184a, the right lower cable guide 184b, the left upper cable guide 184c, and the left lower cable guide 184d provide a path (e.g., a journal) about which a predetermined length of power cables 250a, 250b, 250c, and 250d can wrap about the right cam 160a or the left cam 160b, respectively. In some embodiments, the upper power cables (e.g., the first power cable 250a and the third power cable 250c) extend across the frame 102 and are attached to limb mountings 258c and 258a respectively. Similarly, lower power cables (e.g., the second power cable 250b and the fourth power cable 250d) extend across the frame 102 and are attached to limb mountings 258d and 258b, respectively. In some embodiments, two or more power cables 250 can correspond to each cable guide 184 of the crossbow 100 (e.g., in embodiments where each cable guide 184 receives, takes-up, lets-out, or otherwise engages with two or more power cable end portions 254). In some embodiments, a respective cam 160 (e.g., the right cam 160a and / or the left cam 160b) includes an opening (e.g., gap, aperture, hole) therein. In such embodiments, a respective power cable 250 may be routed through the opening of the respective cam 160 such that the respective power cable 250 engages with both a respective upper cable guide 184 and a respective lower cable guide 184 of the respective cam 160. For example, the right cam 160a may include an opening configured to receive the first power cable 250a such that the first power cable 250a engages with both the right upper cable guide 184a and the right lower cable guide 184b of the right cam 160a. In such an example, the first end portion 254a of the first power cable 250a may be split such that a first split end of the first power cable 250a engages with the right upper cable guide 184a and a second split end of the first power cable 250a engages with the right lower cable guide 184b. In such an example, the crossbow 100 may omit the third power cable 250c. By way of another example, the left cam 160b may include an opening configured to receive the third power cable 250c such that the third power cable 250c engages with both the left upper cable guide 184c and the left lower cable guide 184d of the left cam 160b. By way of yet another example, the right cam 160a may include an opening configured to receive the second power cable 250b such that the second power cable 250b engages with both the right upper cable guide 184a and the right lower cable guide 184b of the right cam 160a. By way of still another example, the left cam 160b may include an opening configured to receive the fourth power cable 250d such that the thi fourth power cable 250d engages with both the left upper cable guide 184c and the left lower cable guide 184d of the left cam 160b.

[0070] The right upper cable guide 184a, the right lower cable guide 184b, the left upper cable guide 184c, and the left lower cable guide 184d are configured to draw a predetermined length of the power cables 250a, 250b, 250c, and 250d onto the right upper cable guide 184a, the right lower cable guide 184b, the left upper cable guide 184c, and the left lower cable guide 184d when the string carrier 122 operates to pull the drawstring 124 to the cocked position (e.g., when the crossbow 100 is transitioned from the released configuration to the drawn configuration). This has the effect of drawing the free ends 152 of the limbs 150 inwardly against the resilient bias of the limbs 150 and stores potential energy in the limbs 150.

[0071] As shown in FIGS. 5, 6, and 17-20, the right and left upper cable guides 184a and 184c are configured such that power cables 250a and 250c cross the center rail 110 within an upper cable slide 260. The upper cable slide 260 is configured to be slidable in a longitudinal direction within an aperture of the string cover 120. Similarly, right and left lower cable guides 184b and 184d are configured such that power cables 250b and 250d cross the center rail 110 within a lower cable slide 262. The lower cable slide 262 is configured to be slidable in a longitudinal direction within an aperture of the frame 102 and positioned below the center rail 110. The upper cable slide 260 and the lower cable slide 262 provide a vertical separation between the upper power cables 250a and 250c and the lower power cables 250b and 250d that enables the power cables 250 to cross over the center rail 110 without interfering with the movement of string carrier 122 or a projectile within the space provided between center rail 110 and the string cover 120. This approach thereby facilitates the crossbow 100 to be more compact while still retaining desired functionality including helping to ensure that a balanced application of force is made.

[0072] Additionally, in this embodiment, by routing the power cables 250 directly from the cable guides 184 to the limb mountings 258, the predetermined length of the power cables 250 that is available for winding on the upper and lower cable guides 184 can be greater. By using a spiral or helical winding of the cable about the cable guides 184, it becomes possible to store a greater length of the power cables 250 on each of the cable guides 184, and to do so with greater radius of winding to reduce the stresses experienced by the power cables 250.

[0073] The drawstring 124 includes a right end portion 266 (e.g., a second end portion, the right end portion of the right loop portion 208, terminal portion, looped end, outermost portion, or other end portion) and a left end portion 270 (e.g., a first end portion, the left end portion of the left loop portion 204, terminal portion, looped end, outermost portion, or other end portion). The right end portion 266 is configured to be coupled to (e.g., wrapped around, mounted at, etc.) the right cam 160a at the right drawstring attachment post 180a. The drawstring 124 (e.g., the right loop portion 208) is configured to be routed along an outer circumference of the right cam 160a within the right drawstring journals 164a and 164b. For example, the right loop portion 208 may include a right upper portion 208a configured to wrap around the right cam 160a within the right upper drawstring journal 164a and a right lower portion 208b configured to wrap around the right cam 160a within the right lower drawstring journal 164b. In such an example, the right upper portion 208a and the right lower portion 208b of the right loop portion 208 may be substantially parallel with each other and with the rotation plane P. The right upper drawstring journal 164a and the right lower drawstring journal 164b provide a path (e.g., a journal) about which a predetermined length of the drawstring 124 can wrap about the right cam 160a.

[0074] The left end portion 270 of the drawstring 124 is configured to be coupled to (e.g., wrapped around, mounted at, etc.) the left cam 160b at the left drawstring attachment post 180b. The drawstring 124 (e.g., the left loop portion 204) is configured to be routed along an outer circumference of the left cam 160b within the left drawstring journals 164c and 164d. For example, the left loop portion 204 may include a left upper portion 204a configured to wrap around the left cam 160b within the left upper drawstring journal 164c and a left lower portion 204b configured to wrap around the left cam 160b within the left lower drawstring journal 164d. In such an example, the left upper portion 204a and the left lower portion 204b of the left loop portion 204 may be substantially parallel with each other and with the rotation plane P. The left upper drawstring journal 164c and the left lower drawstring journal 164d provide a path (e.g., a journal) about which a predetermined length of the drawstring 124 can wrap about the left cam 160b.

[0075] In the released configuration, the right loop portion 208 is let out of the right cam 160a (e.g., the right upper drawstring journal 164a and the right lower drawstring journal 164b) and routed in a lateral direction in a direction towards the frame 102. Similarly, the left loop portion 204 is let out of the left cam 160b (e.g., the left upper drawstring journal 164c and the left lower drawstring journal 164d) and routed in a lateral direction in a direction towards the frame 102. The center portion 200 extends between the right loop portion 208 and the left loop portion 204 in a lateral direction across the frame 102 and the center rail 110. In the released configuration, the center portion 200 a section of the drawstring 124 to nock (e.g., selectively couple, load, etc.) a projectile thereto.

[0076] Referring particularly to FIGS. 6, 19, and 20, the crossbow 100 is shown in the drawn configuration, with substantially a full portion of the predetermined length of the drawstring 124 let out from the right cam 160a and the left cam 160b. In such an embodiment, the center portion 200 may be retained by the string carrier 122 as the string carrier 122 translates in a direction towards the proximal end 116 of the crossbow 100, thereby transitioning the crossbow 100 to the drawn configuration. In the drawn configuration, the drawstring 124 is let out from the right cam 160a and the left cam 160b at tangent points 274a and 274b such that a cam gap 278 extends therebetween.

[0077] In the drawn configuration, the crossbow 100 is configured to fire a projectile, and the drawstring 124 is contained within the lateral boundaries provided by center rail 110 and the string cover 120. The string cover 120 may be sized to accommodate the cam gap 278 at a high end of a range of distances between the tangent points 274, so that the drawstring 124 may be contained within string cover 120. In such an embodiment, the string carrier 122 may capture a segment of the drawstring 124 (e.g., a segment of the center portion 200) that is smaller than the cam gap 278, thereby causing the drawstring 124 to form a V-shaped configuration in the drawn configuration with the narrow portion of the “V” near the proximal end 116. Accordingly, in some embodiments, the string cover 120 may be optionally narrower near the proximal end 116. In the drawn configuration, the tension forces on the drawstring 124 on opposite sides of the string carrier 122 (e.g., the left loop portion 204 and the right loop portion 208) are substantially the same.

[0078] According to an exemplary embodiment, when the crossbow 100 is in the drawn configuration, an angle formed between the left loop portion 204 and the projectile axis A is substantially similar to an angle formed between the right loop portion 208 and the projectile axis A when viewed from the top view.

[0079] When drawstring 124 is released by string carrier 122 (e.g., in response to a user engaging the trigger 134), potential energy is released from the limbs 150 as the limbs 150 separate (e.g., move away from the frame 102). This separation compels the right cam 160a and the left cam 160b to rotate rapidly to let out lengths of the power cables 250 stored along the cable guides 184. This, in turn causes the predetermined lengths of the drawstring 124 to be wound onto the drawstring journals 164. For example, in response to the drawstring 124 being released from the string carrier 122, the right cam 160a rotates in a clockwise direction about the right cam axis B and the left cam 160b rotates in a counterclockwise direction about the left cam axis C (when viewed from FIGS. 18 and 20). In turn, the right upper cable guide 184a lets out the first power cable 250a, the right lower cable guide 184b lets out the second power cable 250b, the left upper cable guide 184c lets out the third power cable 250c, and left lower cable guide 184d lets out the fourth power cable 250d. Additionally, in turn, the right upper portion 208a of the right loop portion 208 is taken up (e.g., received within, wound about, etc.) by the right upper drawstring journal 164a, the right lower portion 208b of the right loop portion 208 is taken up by the right lower drawstring journal 164b, the left upper portion 204a of the left loop portion 204 is taken up by the left upper drawstring journal 164c, and the left lower portion 204b of the left loop portion 204 is taken up by the left lower drawstring journal 164d.

[0080] During firing operations, as the potential energy is released from the limbs 150 as the limbs 150 separate, the cam gap 278 between the tangent point 274 increases. For example, during firing, the right limbs 150a and 150b laterally separate from the left limbs 150c and 150d. Because the right cam 160a and the left cam 160b are mounted to the limbs 150, the right cam 160a and the left cam 160b also laterally separate, thereby laterally displacing the tangent points 274 and increasing the cam gap 278. Substantially simultaneously, the right cam 160a and the left cam 160b rotate to draw portions of drawstring 124 onto the drawstring journal 164. In some embodiments, the inertia and drag of the projectile causes the drawstring 124 to maintain a V shape as this occurs, the distance between the vertex of the V and the tangent points 274 closes as the projectile is thrust along the center rail 110 in a direction downrange toward the distal end 106.

[0081] In some embodiments, the drawstring 124 is engaged with a first pulley assembly (e.g., a right pulley assembly, a first cam assembly, a first lever assembly) and a second pulley assembly (e.g., a left pulley assembly, a second cam assembly, a second lever assembly). The at least one power cables 250 may be engaged with at least one of the pulley assemblies. For example, the crossbow 100 may include one power cable 250 engaged with the first pulley assembly and one power cable 250 engaged with the second pulley assembly. The first pulley assembly and the second pulley assembly may be rotatably mounted (e.g., rotatably coupled, rotatably secured) to the right limbs 150a and 150b and the left limbs 150c and 150d, respectively, and can be configured to rotate about a first pulley assembly axis and a second pulley assembly axis, respectively. The first and second pulley assemblies may each include a pulley coupled to a power cable journal via a lever arm. The pulley of each pulley assembly may be configured to rotate about a pulley axis that is parallel with and spaced apart from the respective pulley assembly axis. The lever arm of the pulley assembly may be configured to rotate about the pulley assembly axis. Each pulley may move along an arc about the respective pulley assembly axis as the lever rotates about the pulley assembly axis, which occurs during operation of the crossbow 100 as the drawstring 124 moves between the released position to the drawn position. As the lever rotates about the pulley assembly axis, the pulley rotates about the pulley axis.

[0082] Referring to FIG. 21, a method of manufacturing a drawstring (e.g., drawstring 124) is shown as method 300, according to an exemplary embodiment. The method 300 includes steps 302-316. Each of steps 302-316 are optional. For example, the method 300 can include some, but not all, of steps 302-316. Further, the steps 302-316 need not be performed in the order depicted in FIG. 21.

[0083] At step 302, a plurality of inner strings (e.g., inner strings 212) and serving material (e.g., serving material 224) are provided. At step 304, the inner strings are grouped together to form a core (e.g., core 216) of the drawstring. For example, the core can be formed by grouping multiple inner strings 212 together to form a core having inner string substantially aligned (e.g., axially aligned or extending along a similar path) as depicted in FIG. 10A and as discussed above. In other embodiments, the inner strings can be twisted to relative to each other or relative to some common axis of the bundle of inner strings, as depicted in FIG. 10B and as discussed above. In various embodiments, each of the plurality of inner strings are substantially the same length. In some embodiments, each of the plurality of inner strings are equally pre-tensioned while being twisted such that each inner string experiences a substantially similar tension when the drawstring is installed on the crossbow and when the crossbow is in the released configuration, the drawn configuration, and / or any position or configuration therebetween. In some embodiments, the inner strings are not twisted relative to each other.

[0084] At step 306, a continuous loop is formed. For example, step 306 can include joining opposite ends of the core to form a continuous loop (e.g., continuous loop 220). The opposite ends of the core may be tied together, spliced together, fused or melted together, joined by some adhesive, or otherwise bonded to form the continuous loop.

[0085] At step 308, a center portion, a left loop portion, and a right loop portion are formed. For example, the continuous loop can be twisted such that a center portion (e.g., center portion 200) of the continuous loop is twisted, a left side of the continuous loop forms a left loop portion (e.g., left loop portion 204), and a right side of the continuous loop forms a right loop portion (e.g., right loop portion 208). In some embodiments, step 308 is omitted such that the continuous loop is untwisted.

[0086] At step 310, the left loop portion is served with a serving material. For example, the left loop portion can be served in a first direction (e.g., first direction 228) using a first serving material.

[0087] At step 312 the right loop portion is served using a serving material. For example, the right loop portion can be served in a second direction (e.g., second direction 232) using a second serving material. The second direction is opposite the first direction. For example, the first serving material may be served around the entirety of the left loop portion in the first direction that is clockwise, and the second serving material may be served around the entirety of the right loop portion in the second direction that is counterclockwise (e.g., clockwise and counterclockwise being opposite directions). The second serving material served on the right loop portion can be the same as or different than the first serving material served on the left loop portion. In some embodiments, step 308 is performed after steps 310 and 312. For example, after serving the left loop portion and the right loop portion, the continuous loop may be twisted such that a left portion of the drawstring forms the left loop portion, a right portion of the drawstring forms the right loop portion, and the twisted portion of the drawstring forms the center portion.

[0088] At step 314, the center portion is served using a third serving material. In some embodiments, the center portion is served such that a left side of the center portion is served in an opposite direction that a right side of the center portion is served in. In some embodiments, the serving of the center portion overlaps at least a portion of the servings of the left and right loop portions. In some embodiments, the first serving material served on left loop portion and the second serving material served on the right loop portion are different than the third serving material used to serve the center portion. In other embodiments, one or more of the first serving material served on left loop portion and the second serving material served on the right loop portion are the same as than the third serving material used to serve the center portion. After completing steps 302-314, a drawstring (e.g., drawstring 124) is created. In some embodiments, serving the left loop portion and the right loop portion in opposing directions facilitates a construction of the drawstring having substantially no rotational bias one direction or another.

[0089] At step 316, the drawstring created after steps 302-314 is operatively coupled to a cam assembly (e.g., cam assembly 108) included in a crossbow (e.g., crossbow 100). The drawstring is coupled to the cam assembly such that drawing the drawstring rotates the cam assembly and transitions the crossbow between a released configuration and a drawn configuration. For example, a left end portion of the left loop portion is wrapped around a left drawstring attachment post (e.g., left drawstring attachment post 180b) of a dual track left cam (e.g., left cam 160b) and routed along an outer circumference of the dual track left cam within each track (e.g., left upper drawstring journal 164c and left lower drawstring journal 164d). The dual track left cam routes the left loop portion in a direction towards a center rail of the crossbow. Similarly, a right end portion of the right loop portion is wrapped around a right drawstring attachment post (e.g., right drawstring attachment post 180a) of a dual track right cam (e.g., right cam 160a) and routed along an outer circumference of the dual track right cam within each track (e.g., right upper drawstring journal 164a and right lower drawstring journal 164b). The dual track right cam routes the right loop portion in a direction towards the center rail of the crossbow. The center portion is configured to extend in a lateral direction across the center rail and between the left and right loop portions.

[0090] Referring to FIG. 22, a method of manufacturing a drawstring (e.g., drawstring 124) is shown as method 350, according to an exemplary embodiment. The method 350 includes steps 352-364. Each of steps 352-364 are optional. For example, the method 350 can include some, but not all, of steps 352-364. Further, the steps 352-364 need not be performed in the order depicted in FIG. 22.

[0091] At step 352, a core material (e.g., the core 216) and serving material (e.g., serving material 224) are provided. For example, the core can be formed by grouping multiple inner strings together to form a core having inner string substantially aligned (e.g., axially aligned or extending along a similar path) as depicted in FIG. 10A and as discussed above. In some embodiments, the inner strings can be twisted to relative to each other or relative to some common axis of the bundle of inner strings, as depicted in FIG. 10B and as discussed above. In other embodiments, the inner strings are not twisted relative to each other.

[0092] At step 354, a continuous loop is formed. For example, step 306 can include joining opposite ends of the core material to form a continuous loop (e.g., continuous loop 220). The opposite ends of the core material may be tied together, spliced together, fused or melted together, joined by some adhesive, or otherwise bonded to form the continuous loop including a center portion (e.g., center portion 200), a left loop portion (e.g., left loop portion 204), and a right loop portion (e.g., right loop portion 208).

[0093] At step 356, the continuous loop is twisted. For example, the continuous loop may be twisted such that the center portion of the continuous loop is twisted, the left loop portion of the continuous loop forms a left loop, and the right loop portion of the continuous loop forms a right loop. In some embodiments, step 356 is omitted such that the continuous loop is not twisted.

[0094] At step 358, at least a portion of the left loop portion is served with the serving material in at least one direction. For example, a first portion of the left loop portion may be served and a second portion of the left loop portion may be served such that the left loop portion includes at least one unserved portion. In such an example, the first portion may be served in a first serving direction (e.g., first direction 228) and the second portion may be served in a second serving direction (e.g., second direction 232) opposite the first direction.

[0095] At step 360, at least a portion of the right loop portion is served with the serving material in at least one direction. For example, a first portion of the right loop portion may be served and a second portion of the right loop portion may be served such that the right loop portion includes at least one unserved portion. In such an example, the first portion may be served in a first serving direction (e.g., first direction 228) and the second portion may be served in a second serving direction (e.g., second direction 232) opposite the first direction.

[0096] At steps 358 and 360, the drawstring may be arranged such that the portions of the drawstring being served (e.g., the left loop portion and the right loop portion) are substantially straight (and the center portion is curved). Further, at steps 358 and 360, the at least one portions of the left loop portion and the right loop portion are served in a manner such that the drawstring has substantially no rotational bias one direction or another. In other words, the drawstring is served to maintain a neutrally balanced string assembly.

[0097] At step 362, the center portion of the drawstring is twisted. By way of example, the center portion may be twisted in addition to the twists applied at step 356. By way of another example, in embodiments where step 356 is omitted, the center portion is twisted for the first time. In some embodiments, step 362 is omitted such that the center portion is not twisted. By way of example, the continuous loop may be twisted at step 356 and the center portion may not be twisted more at step 362. By way of another example, the continuous loop may not be twisted at step 356 and the center portion may not be twisted at step 362 such that the center portion remains entirely not twisted.

[0098] At step 364, at least a portion of the center portion is served with the serving material in at least one direction. The drawstring may be rotated (e.g., about 90 degrees counterclockwise) after serving one or more portions of the left loop portion and the right loop portion and prior to serving the center portion. As such, the top and bottom portions of the center portion may be substantially straight (e.g., parallel with each other), and the left loop portion and the right loop portion may be curved (e.g., arced, looped) to form left and right loops, respectively. The center portion may be served to include a first served portion and a second unserved portion positioned (i) between the left loop portion and the first served portion and (ii) between the right loop portion and the first served portion. In some embodiments, the serving added to the center portion is added in one or more directions to counteract the rotational bias created within the drawstring due to the twists in the core, the serving directions of the left loop portion, the serving directions of the right loop portion, among other factors. Serving the center portion in this manner facilitates providing a drawstring that is substantially balanced so as to provide a neutral torsional force condition with substantially no torsional bias (e.g., a counteracting torsional bias) between the left loop portion and the right loop portion. In some embodiments, the center portion is served (e.g., entirely in a single direction) to create a bias (e.g., torsional bias, rotational bias) in the serving direction within the center portion. In such embodiments, the direction of the bias (e.g., torsional bias, rotational bias) is the same as a direction that the projectile launched from the crossbow (e.g., a projectile nocked to the center portion of the drawstring and fired from the crossbow) has a tendency to rotate when launched (e.g., thrust, propelled, fired, released) from the crossbow. For example, the projectile launched from the crossbow can include fletching (e.g., one or more vanes, feathers, or other stabilizing attachments) that cause the projectile rotate about a longitudinal axis of the projectile as the projectile is launched from the crossbow. In such embodiments, the center portion can be served such that the direction of a bias (e.g., a torsional bias, a rotational bias) of the center portion is substantially the same direction as the direction in which the projectile has a tendency to rotate after the projectile is launched from the crossbow. After completing steps 352-364, a drawstring (e.g., drawstring 124) is created.

[0099] As utilized herein with respect to numerical ranges, the terms “approximately,”“about,”“substantially,” and similar terms generally mean + / −10% of the disclosed values. When the terms “approximately,”“about,”“substantially,” and similar terms are applied to a structural feature (e.g., to describe its shape, size, orientation, direction, etc.), these terms are meant to cover minor variations in structure that may result from, for example, the manufacturing or assembly process and are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.

[0100] It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

[0101] The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using one or more separate intervening members, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.

[0102] References herein to the positions of elements (e.g., “top,”“bottom,”“above,”“below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.

[0103] Although the figures and description may illustrate a specific order of method steps or operations, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above.

[0104] It is important to note that the construction and arrangement of the projectile launcher as shown in the various exemplary embodiments is illustrative only. Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.

Examples

Embodiment Construction

[0027]Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

[0028]Referring to FIGS. 1-5, a crossbow (e.g., bow, projectile launcher, etc.), shown as crossbow 100, is shown in a released configuration (e.g., de-cocked position, fired position, un-drawn position, etc.). According to an exemplary embodiment, the crossbow 100 includes a frame (e.g., rail, chassis, body, shell, or other frame member), shown as frame 102, a limb assembly 104 coupled to the frame 102 at a distal end 106 (e.g., front end, down-range end) of the crossbow 100, and a cam assembly 108 coupled to the limb assembly 104.

[0029]The frame102 includes a center rail 110 configured to support ...

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Ser. No. 63 / 619,188, filed Jan. 9, 2024, which is incorporated herein by reference in its entirety.BACKGROUND

[0002] This application relates generally to a projectile launcher.SUMMARY

[0003] One embodiment relates to a crossbow. The crossbow includes a frame, a limb assembly coupled to the frame, a drawstring including a left loop portion, a right loop portion, and a center portion extending between the left loop portion and the right loop portion, and a cam assembly rotatably coupled with the limb assembly. The limb assembly includes a first upper limb, a first lower limb, a second upper limb, and a second lower limb. The cam assembly includes a first cam rotatable about a first cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the right loop portion of the drawstring, and a second cam rotatable about a second cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the left loop portion of the drawstring. The upper drawstring journal of the first cam and the lower drawstring journal of the first cam are vertically offset from each other. The upper drawstring journal of the second cam and the lower drawstring journal of the second cam are vertically offset from each other.

[0004] Another embodiment relates to a cam assembly. The cam assembly includes a drawstring including a left loop portion, a right loop portion, and a center portion extending between the left loop portion and the right loop portion, a first cam rotatable about a first cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the right loop portion of the drawstring, and a second cam rotatable about a second cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the left loop portion of the drawstring. The first cam includes a first upper cable guide extending from a top surface of the first cam along the first cam axis, and a first lower cable guide extending from a bottom surface of the first cam along the first cam axis, such that the upper drawstring journal and the lower drawstring journal of the first cam are positioned between the first upper cable guide and the first lower cable guide. The second cam includes a second upper cable guide extending from a top surface of the second cam along the second cam axis, and a second lower cable guide extending from a bottom surface of the second cam along the second cam axis, such that the upper drawstring journal and the lower drawstring journal of the second cam are positioned between the second upper cable guide and the second lower cable guide.

[0005] Another embodiment relates to a method of manufacturing a drawstring. The method includes providing a plurality of inner strings and serving material, twisting the plurality of inner strings to form a core of the drawstring, joining opposite ends of the core to form a continuous loop, twisting the continuous loop such that a center portion of the continuous loop is twisted, a left side of the continuous loop forms a left loop portion, and a right side of the continuous loop forms a right loop portion, serving at least a portion of the left loop portion using the serving material, serving at least a portion of the right loop portion using the serving material, and serving at least a portion of the center portion using the serving material. A first portion of the left loop portion is served in a first direction using the serving material. A second portion of the left loop portion is served in a second direction using the serving material. A first portion of the right loop portion is served in the first direction using the serving material. A second portion of the right loop portion is served in the second direction using the serving material. The first direction is opposite the second direction.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a left side view of a crossbow, according to an exemplary embodiment.

[0007] FIG. 2 is a top view of the crossbow of FIG. 1, according to an exemplary embodiment.

[0008] FIG. 3 is a front view of the crossbow of FIG. 1, according to an exemplary embodiment.

[0009] FIG. 4 is a rear view of the crossbow of FIG. 1, according to an exemplary embodiment.

[0010] FIG. 5 is a rear view of the crossbow of FIG. 1 with a frame and a string cover removed, according to an exemplary embodiment.

[0011] FIG. 6 is a top view of the crossbow of FIG. 1, according to an exemplary embodiment.

[0012] FIG. 7a is a top view of a right cam of a cam assembly of the crossbow of FIG. 1, according to an exemplary embodiment.

[0013] FIG. 7b is a side view of the right cam of the cam assembly of the crossbow of FIG. 1, according to an exemplary embodiment.

[0014] FIG. 8a is a top view of a left cam of the cam assembly of the crossbow of FIG. 1, according to an exemplary embodiment.

[0015] FIG. 8b is a side view of the left cam of the cam assembly of the crossbow of FIG. 1, according to an exemplary embodiment.

[0016] FIG. 9 is a rear view of a drawstring, according to an exemplary embodiment.

[0017] FIGS. 10A-13 are various views of a method of manufacturing the drawstring of FIG. 9, according to an exemplary embodiment.

[0018] FIG. 14 is a detailed view of left and right loop portions of the drawstring of FIG. 9, according to an exemplary embodiment.

[0019] FIG. 15 is a view of the drawstring of FIG. 9 after a first serving step, according to an exemplary embodiment.

[0020] FIG. 16 is a detailed view of a center portion of the drawstring of FIG. 9 after a second serving step, according to an exemplary embodiment.

[0021] FIG. 17 is a right, rear perspective view of the cam assembly coupled with a limb assembly of the crossbow of FIG. 1 and coupled with the drawstring FIG. 9 in a released configuration, according to an exemplary embodiment.

[0022] FIG. 18 is a top view of the cam assembly coupled with the limb assembly of the crossbow of FIG. 1 and coupled with the drawstring FIG. 9 in the released configuration, according to an exemplary embodiment.

[0023] FIG. 19 is a right, rear view of the cam assembly coupled with the limb assembly of the crossbow of FIG. 1 and coupled with the drawstring FIG. 9 in a drawn configuration, according to an exemplary embodiment.

[0024] FIG. 20 is a top view of the cam assembly coupled with the limb assembly of the crossbow of FIG. 1 and coupled with the drawstring FIG. 9 in the drawn configuration, according to an exemplary embodiment.

[0025] FIG. 21 is a block diagram of a method of manufacturing the drawstring of FIG. 9, according to an exemplary embodiment.

[0026] FIG. 22 is a block diagram of a method of manufacturing the drawstring of FIG. 9, according to an exemplary embodiment.DETAILED DESCRIPTION

[0027] Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

[0028] Referring to FIGS. 1-5, a crossbow (e.g., bow, projectile launcher, etc.), shown as crossbow 100, is shown in a released configuration (e.g., de-cocked position, fired position, un-drawn position, etc.). According to an exemplary embodiment, the crossbow 100 includes a frame (e.g., rail, chassis, body, shell, or other frame member), shown as frame 102, a limb assembly 104 coupled to the frame 102 at a distal end 106 (e.g., front end, down-range end) of the crossbow 100, and a cam assembly 108 coupled to the limb assembly 104.

[0029] The frame102 includes a center rail 110 configured to support a projectile (e.g., an arrow, a bolt, etc.) when the crossbow 100 is loaded and guide the projectile during firing operations. A riser 112 is coupled to the frame 102 at the distal end 106 of the crossbow 100 and is configured to couple the limb assembly 104 to the frame 102. In some embodiments, the crossbow 100 includes a stock 114 coupled to the frame 102 at a proximal end 116 (e.g., rear end) of the crossbow 100. The stock 114 may provide a support surface for a user to facilitate stabilizing the crossbow 100 during firing operations. The stock 114 may be removably coupled to the frame 102 to facilitate interchangeability of the stock 114 (e.g., a first stock 114 may be replaced with a second stock 114 having a different shape or configuration than the first stock 114). In some embodiments, the crossbow 100 does not include the stock 114. In some embodiments, the stock 114 is integrally formed with the frame 102.

[0030] As shown in FIGS. 1, 3, and 5, the frame 102 includes a rest (e.g., support), shown as arrow rest 118, configured to support the projectile when the crossbow 100 is loaded and to guide the projectile during firing operations such that the projectile is suspended above the center rail 110 when the crossbow 100 is in a drawn (e.g., cocked) configuration. Generally, the arrow rest 118 supports an end of the projectile such that the projectile is pointed in a down-range direction (e.g., in a direction towards a target positioned down-range from the distal end 106 of the crossbow) such that when the crossbow 100 is fired, the projectile is propelled (e.g., shot, thrust, fired, etc.) from the crossbow 100 in a down-range direction along a projectile axis A (e.g., longitudinal centerline, flight path, etc.). The projectile axis A may be an axis defined by the frame 102, the center rail 110 of the frame 102, or some other portion of the crossbow 100. The projectile axis A is an axis along which the projectile is loaded into the crossbow 100 and along which the projectile travels during operation of the crossbow 100 as the crossbow 100 is fired (e.g., as the crossbow 100 or a drawstring of the crossbow 100 moves from the drawn configuration to the released configuration). The projectile axis A extends in a direction between the distal end 106 and the proximal end 116 of the crossbow 100 and is substantially parallel with the center rail 110.

[0031] In some embodiments, the frame 102 includes multiple portions (e.g., a left and a right side, multiple frame shells, a top portion and a bottom portion, or some other portions) that are fastened together to form the frame 102. In some embodiments, the frame 102 is divided into more than two sections that are removably coupled or may not be divided into any sections. In some embodiments, the frame 102 is provided as a single, integrally formed section or structure. For example, the center rail 110, the riser 112, and the stock 114 may be integrally formed together as a unitary structure. The frame 102 or one or more components thereof (e.g., the center rail 110, the riser 112) may include a plurality of apertures, pockets, recesses, or other voids throughout that reduce weight. In some embodiments, the frame 102 includes no apertures. The frame 102 can be constructed of materials including plastic, carbon fiber composite, fiber glass, polymeric materials, synthetic materials, wood, aluminum, or one or more other materials.

[0032] As shown in FIGS. 1 and 2, the frame 102 includes a string cover 120. The string cover 120 extends over the center rail 110 permitting movement of a string carrier 122 and a drawstring 124 in a space laterally bounded by the center rail 110 and the string cover 120. In some embodiments, the string cover 120 is at least partially transparent to assist the user in loading and unloading a projectile, and to monitor activities of the drawstring 124 and the string carrier 122. As shown in FIG. 1, the string cover 120 includes a plurality of apertures (e.g., holes, gaps, spaces, etc.), shown as cut-outs 126. In some embodiments, the string cover 120 includes no cut-outs 126. In another embodiment, some or all of the string cover 120 may be constructed from a transparent material. The cut-outs 126 may be configured (e.g., spaced, sized, oriented, positioned, etc.) along the string cover 120 such that a user is unable to place their fingers in the drawstring path (e.g., in the space defined by the center rail 110 and the string cover 120, along the projectile axis A, etc.). In some embodiments, the string cover 120 is integrally formed with the frame 102 (e.g., the center rail 110). In other embodiments, the string cover 120 is selectively removable from the frame 102. In other embodiments, the crossbow 100 does not include the string cover 120. In such embodiments, the drawstring 124 is positioned vertically above the center rail 110 and can be exposed or accessible from above.

[0033] The string carrier 122 is configured to translate along the center rail 110 between an extended position and a retracted position to facilitate transitioning the crossbow 100 between released and drawn configurations (e.g., cocking the crossbow 100, de-cocking the crossbow). For example, during cocking (e.g., drawing) operations the string carrier 122 translates (e.g., slides, moves, etc.) forward along the center rail 110 toward the riser 112 to engage the drawstring 124 while the crossbow 100 is in the released configuration. The string carrier 122 selectively may be selectively coupled to the drawstring 124 such that when the string carrier 122 is translated rearward along the center rail 110 toward the proximal end 116 of the crossbow 100, the crossbow 100 transitions from the released configuration to the drawn configuration. The drawstring 124 is in a drawn (e.g., cocked) position or configuration when the crossbow 100 is in the drawn configuration. The drawstring 124 is in a released (e.g., uncocked, undrawn) position or configuration when the crossbow 100 is in the released configuration.

[0034] As shown in FIGS. 1-4, the string cover 120 includes a mount (e.g., a rail, a tactical, picatinny, or weaver mounting rail, etc.), shown as scope mount 128. In some embodiments, the scope mount 128 is integrally formed on a top surface of the string cover 120. In other embodiments, the scope mount 128 is selectively removable from the string cover 120. The scope mount 128 includes a platform on which one or more accessories (e.g., sights, scopes, lasers, etc.), shown as scope 130, may be coupled to the crossbow 100. The scope mount 128 includes a plurality of protrusions and grooves that secure the scope 130 and / or one or more other accessories. In some embodiments, the scope 130 includes a reticle with gradations corresponding to the ballistic drop of projectiles of a particular weight. In some embodiments, the crossbow 100 includes a scope mount rail positioned partially over the center rail 110 via a cantilever arm, a platform that at least partially straddles the projectile axis A, or some other structure other than the string cover 120.

[0035] A grip 132 is positioned between the distal end 106 and the proximal end 116 of the crossbow 100 along a bottom surface of the frame 102. In some embodiments, the grip 132 is integrally formed with the frame 102. The grip 132 includes an opening for a user to rest or place a finger. The grip 132 can have one or more concave indentations that are generally ergonomic. The grip 132 provides a point of support for a user of the crossbow 100. The grip 132 can be held by the user's hand. In some embodiments, the grip 132 is a pistol style grip. In some embodiments, a trigger 134 is positioned in the opening of the grip 132. The trigger 134 may be operatively coupled to a firing mechanism and the string carrier 122 such that actuating the trigger 134 (e.g., pulling the trigger 134) disengages the string carrier 122 from the drawstring 124 to fire the crossbow 100 and the projectile downrange. In some embodiments, the trigger 134 is aesthetic (e.g., the trigger 134 does not engage a firing mechanism).

[0036] According to the exemplary embodiment shown in FIGS. 1-4, the frame 102 includes a mount (e.g., a rail, a tactical, picatinny, or weaver mounting rail, etc.), shown as bottom mount 136. In some embodiments, the bottom mount 136 is integrally formed on a bottom surface of the frame 102. In other embodiments, the bottom mount 136 is selectively removable from the frame 102. The bottom mount 136 includes a platform on which one or more accessories (e.g., grips, cocking handles, quivers, lasers, etc.) may be coupled to the crossbow 100. The platform may be substantially similar to the scope mount 128 in that the platform may include a plurality of protrusions and grooves that secure the one or more other accessories. As shown, a lower grip 138, a quiver 140, and a cocking handle 142 are coupled to the crossbow 100 by way of the bottom mount 136. In some embodiments, the lower grip 138 is integrally formed with a bottom surface of the frame 102.

[0037] As shown in FIGS. 1-5, the riser 112 is configured to couple the limb assembly 104 to the crossbow 100. The limb assembly 104 includes a right limb assembly 104a and a left limb assembly 104b. The crossbow includes components defined as “right” and “left”. The “right” and the “left” components are substantially similar and mirrored as discussed below. The right limb assembly 104a includes a right upper limb 150a (e.g., a first upper limb) and a right lower limb 150b (e.g., a first lower limb). The left limb assembly 104b includes a left upper limb 150c (e.g., a second upper limb) and a left lower limb 150d (e.g., a second lower limb). The right upper limb 150a, the right lower limb 150b, the left upper limb 150c, and the left lower limb 150d may be collectively hereinafter referred to as limbs 150. In other embodiments, the crossbow 100 can include only one limb per side (e.g., rather than an upper and lower limb per side). For example, the right limb assembly 104a can include only a single right limb and the left limb assembly 104b can include only a single left limb. In yet other embodiments, the crossbow 100 can include more than two (e.g., three, four, five, or some other number of) limbs per side. For example, the right limb assembly 104a can include four limbs and the left limb assembly 104b can include four limbs.

[0038] The riser 112 is configured to join one end of each of the right upper limb 150a, the right lower limb 150b, the left upper limb 150c, and the left lower limb 150d to the center rail 110. In the illustrated embodiment, the limbs 150 have a generally concave shape directed at least partially toward the projectile axis A of the center rail 110 and extend from the riser 112 in a direction toward the proximal end 116 of the crossbow 100, ending at free ends 152a, 152b, 152c, and 152d. The limbs 150 are formed from an elastically deformable material shaped to resiliently flex during cocking. Potential energy is stored in the limbs 150 as they flex. The material used to form the limbs 150, the construction of limbs 150, and the shape of limbs 150 are selected to allow the potential energy stored in limbs 150 to be rapidly released during firing.

[0039] The limb assembly 104 includes mounts (e.g., pivots, connectors, etc.), shown as pivot mounts 154a, 154b, 154c, and 154d, coupled to the proximate free ends 152a, 152b, 152c, and 152d of the right upper limb 150a, the right lower limb 150b, the left upper limb 150c, and the left lower limb 150d respectively. The pivot mounts 154 are configured to receive a pivot pin (e.g., axle, shaft, post, etc.), shown as pivot pin 156, to rotatably couple the cam assembly 108 to the limb assembly 104. A right pivot pin 156a is mounted at an upper end to a right upper pivot mount 154a and at a lower end to a right lower pivot mount 154b and extends across a gap formed between the right upper limb 150a and the right lower limb 150b. A right cam 160a (e.g., a first cam) included in the cam assembly 108 is mounted to right pivot pin 156a (e.g., received by the right pivot pin 156a) within the gap formed between the right upper limb 150a and the right lower limb 150b. In some embodiments, the right pivot pin 156a is an independent component from the right cam 160a such that the right pivot pin 156a is fastened to the right cam 160a. In this way, the right pivot pin 156a is detachably coupled to the right cam 160a. Because the right pivot pin 156a is detachably coupled to the right cam 160a, the right pivot pin 156a can include a chamfer, round, fillet, or other feature at an interface between the right pivot pin 156a and the right cam 160a or elsewhere on the right pivot pin 156a that can substantially prevent abrasion or wear of the drawstring 124 coupled to the right cam 160a. In other embodiments, the right pivot pin 156a is integrally formed with the right cam 160a. The right pivot pin 156a may be received by one or more bearings positioned within the right upper pivot mount 154a and the right lower pivot mount 154b such that the right pivot pin 156a and the right cam 160a are configured to rotate relative to the right limb assembly 104a. In some embodiments, the right pivot pin 156a is fixedly coupled to the right limb assembly 104a (e.g., fixed within the right upper pivot mount 154a and the right lower pivot mount 154b) such that the right cam 160a is configured to rotate about the right pivot pin 156a. In some embodiments, the crossbow 100 includes two or more right cams 160a or two or more left cams 160b. For example, two right cams 160a can be coupled to the right limb assembly 104a and can rotate about one or more right pivot pins 156a (e.g., a common pivot pin 156a or separate pivot pins 156a).

[0040] Similarly, a left pivot pin 156b is mounted at an upper end to a left upper pivot mount 154c and at a lower end to a left lower pivot mount 154d and extends across a gap between left upper limb 150c and left lower limb 150d. A left cam 160b (e.g., a second cam) included in the cam assembly 108 is mounted to the left pivot pin 156b (e.g., received by the left pivot pin 156b) within a gap formed between the left upper limb 150c and the left lower limb 150d. In some embodiments, the left pivot pin 156b is an independent component from the left cam 160b such that the left pivot pin 156b is fastened to the left cam 160b. In this way, the left pivot pin 156b is detachably coupled to the left cam 160b. Because the left pivot pin 156a is detachably coupled to the left cam 160b, the left pivot pin 156b can include a chamfer, round, fillet, or other feature at an interface between the left pivot pin 156b and the left cam 160b or elsewhere on the left pivot pin 156b that can substantially prevent abrasion or wear of the drawstring 124 coupled to the left cam 160b. In other embodiments, the left pivot pin 156b is integrally formed with the left cam 160b. The left pivot pin 156b may be received by one or more bearings positioned within the left upper pivot mount 154c and the left lower pivot mount 154d such that the left pivot pin 156b and the left cam 160b are configured to rotate relative to the left limb assembly 104b. In some embodiments, the left pivot pin 156b is fixedly coupled to the left limb assembly 104b (e.g., fixed within the left upper pivot mount 154c and the left lower pivot mount 154d) such that the left cam 160b is configured to rotate about the left pivot pin 156b.

[0041] As shown in FIGS. 5-8, the cam assembly 108 includes the right cam 160a and the left cam 160b that are rotatable about a right cam axis B (e.g., a first cam axis) and a left cam axis C (e.g., a second cam axis), respectively, within a rotation plane P. For example, the right cam 160a and the left cam 160b define a vertically centered horizontal plane that is co-planar with the rotation plane P. The rotation plane P extends in a lateral direction between the right cam 160a and the left cam 160b and in a longitudinal direction between the distal end 106 and the proximal end 116 of the crossbow 100. In some embodiments, the projectile axis A extends within the rotation plane P. For example, the rotation plane P is a substantially horizontal plane parallel to the extension of the center rail 110.

[0042] Referring particularly to FIGS. 7a and 7b, the right cam 160a has a substantially circular profile. An outer circumference of the right cam 160a includes two right drawstring journals, shown as right upper drawstring journal 164a and right lower drawstring journal 164b, sized to receive the drawstring 124 and direct the drawstring 124 in a direction towards the left cam 160b across the projectile axis A. The right upper drawstring journal 164a and the right lower drawstring journal 164b may be spaced (e.g., vertically offset) such that the right upper drawstring journal 164a is positioned directly vertically above the right lower drawstring journal 164b. For example, a center portion of the right cam 160a, shown as lip 168a, forms at least a portion of both the right upper drawstring journal 164a and the right lower drawstring journal 164b. As shown, the right upper drawstring journal 164a and the right lower drawstring journal 164b are substantially parallel (e.g., within 10° of parallel). In other embodiments, the right upper drawstring journal 164a and the right lower drawstring journal 164b are non-parallel.

[0043] The right cam 160a defines a width 170a between a top surface 171a of the right cam 160a and a bottom surface 171b of the right cam 160a. In some embodiments, the width 170a is between 0.25 inches and 0.5 inches (e.g., 0.315 inches, 0.275 inches, 0.4 inches, or some other width). In other embodiments, the width 170a is otherwise suitably sized (e.g., more than 0.5 inches, less than 0.25 inches, or some other dimension) to allow the right upper drawstring journal 164a and the right lower drawstring journal 164b to receive the drawstring 124.

[0044] The right cam 160a defines a distance 172a between a center point of the right upper drawstring journal 164a and a center point of the right lower drawstring journal 164b. In some embodiments, the distance 172a is between 0.1 inches and 0.2 inches (e.g., 0.135 inches, 0.15 inches, or some other distance). In other embodiments, the distance 172a is otherwise suitably dimensioned (e.g., more than 0.2 inches, less than 0.1 inches, or some other dimension).

[0045] The right upper drawstring journal 164a and the right lower drawstring journal 164b define a radius 174a, a radial depth 176a, and an angle of separation 178a sized to receive the drawstring 124. In some embodiments, the radius 174a defined by the right upper drawstring journal 164a and the right lower drawstring journal 164b is equal to a radius of the drawstring 124. In other embodiments, the radius 174a is greater than the radius of the drawstring. In some embodiments, the radius 174a is between 0.05 inches and 0.1 inches (e.g., 0.09 inches, 0.075 inches, or some other dimension). In some embodiments, the radial depth 176a is between 0.1 inches and 0.2 inches (e.g., 0.178 inches, 0.15 inches, or some other dimension). In some embodiments, the angle of separation 178a is between 5 degrees and 7 degrees (e.g., 6.176 degrees, 6 degrees, or some other angle). In other embodiments, the radius 174a, the radial depth 176a, and / or the angle of separation 178a are otherwise suitably dimensioned.

[0046] The right cam 160a includes a right drawstring attachment post 180a (e.g., an anchor, a mounting point) positioned along the outer circumference of the right cam 160a and extends radially from the right cam 160a. In some embodiments, the right drawstring attachment post 180a is vertically centered on an outer radial surface (e.g., an outer circumference) of the right cam 160a within the rotation plane P. The right drawstring attachment post 180a is configured to couple a right end portion (e.g., a right end portion 266 as discussed below, a terminal portion, a looped end, an outermost portion, or some other end portion) of the drawstring 124 to the right cam 160a and is sized and shaped to maintain (e.g., hold, secure) the right end portion of the drawstring 124 around the right drawstring attachment post 180a when the crossbow 100 is in the drawn configuration and the released configuration. For example, the right drawstring attachment post 180a may include a groove sized to maintain the right end portion of the drawstring 124 around the right drawstring attachment post 180a when the crossbow 100 is in the drawn configuration and the released configuration. The right drawstring attachment post 180a is configured to vertically space the drawstring 124 such that the drawstring 124 is directed in a direction toward and received within the right upper drawstring journal 164a and the right lower drawstring journal 164b. In some embodiments, the right drawstring attachment post 180a is an independent component from the right cam 160a such that the right drawstring attachment post 180a is fastened to the right cam 160a. In this way, the right drawstring attachment post 180a is detachably coupled to the right cam 160a. In other embodiments, the right drawstring attachment post 180a is integrally formed with the right cam 160a.

[0047] Referring still to FIGS. 7a and 7b, the right cam 160a includes at least one cable guide 184. As shown, the right cam 160a includes a right upper cable guide 184a (e.g., a first upper cable guide) and a right lower cable guide 184b (e.g., a first lower cable guide). The right upper cable guide 184a and the right lower cable guide 184b each include a journal 186 (e.g., helical journal, spiral journal, a journal having a three-dimensional curvature or path) sized to receive, take-up, let-out, or otherwise engage with at least one power cable (e.g., a power cable 250 as discussed below). The right upper cable guide 184a extends in an upward vertical direction (e.g., substantially perpendicular to) from the top surface 171a of the right cam 160a. Similarly, the right lower cable guide 184b extends in a downward vertical direction (e.g., substantially perpendicular to) from the bottom surface 171b of the right cam 160a. For example, the right upper cable guide 184a and the right lower cable guide 184b extend from the top surface 171a and the bottom surface 171b of the right cam 160a such that the right upper drawstring journal 164a and the right lower drawstring journal 164b are positioned between the right upper cable guide 184a and the right lower cable guide 184b. The right upper cable guide 184a and the right lower cable guide 184b may extend along the right cam axis B. The right cam 160a includes an aperture (e.g., hole, opening, passageway) through which the right pivot pin 156a extends such that the right cam 160a and the right pivot pin 156a are coaxial with and rotate about the right cam axis B when the crossbow 100 is transitioned between the drawn and released configurations. In some embodiments, the journal 186 (e.g., path, groove, slot, notch, or other feature) of the right upper cable guide 184a and the right lower cable guide 184b have the same radius 174a, radial depth 176a, and / or angle of separation 178a as the right upper drawstring journal 164a and the right lower drawstring journal 164b. In other embodiments, the journal 186 is otherwise suitably dimensioned to receive a power cable. In some embodiments, the right cam 160a includes two cable guides, three cable guides, four cable guides, or some other number of cable guides. For example, the right cam 160a can include more than one right upper cable guide 184a, more than one right lower cable guide 184b, or some other cable guide configured to receive, take-up, let-out, or otherwise engage with a power cable. In some embodiments, each cable guide 184 can engage with two or more power cables.

[0048] The right cam 160a includes a right upper power cable post 188a (e.g., an anchor, a mounting point) positioned on the top surface 171a of the right cam 160a that extends in a substantially upward vertical direction from the right cam 160a. The right cam 160a includes a right lower power cable post 188b (e.g., an anchor, a mounting point) positioned on the bottom surface 171b of the right cam 160a that extends in a substantially downward vertical direction from the right cam 160a. The right upper power cable post 188a and the right lower power cable post 188b are configured to couple an end portion (e.g., a terminal portion, a looped end, an outermost portion, or some other end portion) of a power cable (e.g., the power cable 250) to the right cam 160a and is sized and shaped to maintain (e.g., hold, secure) the respective end portion of the power cable around the right upper power cable post 188a or the right lower power cable post 188b when the crossbow 100 is in the drawn configuration and the released configuration. For example, the right upper power cable post 188a and the right lower power cable post 188b may include a groove sized to maintain an end portion (e.g., a terminal portion, a looped end, outermost portion, or other end portion) of a power cable around the right upper power cable post 188a and the right lower power cable post 188b when the crossbow 100 is in the drawn configuration and the released configuration. The right cam 160a can include two power cable posts, three power cable posts, four power cable posts, or some other number of power cable posts. For example, the right cam 160a can include at least one power cable post per cable end portion that is coupled to the right cam 160a. The right cam 160a can include more than one power cable posts per power cable end portion that is coupled to the right cam 160a.

[0049] The right cam 160a defines a height 190a between a top surface of the right upper cable guide 184a and a bottom surface of the right lower cable guide 184b. In some embodiments, the height 190a is between 1 inch and 1.5 inches (e.g., 1.32 inches, 1.25 inches, or some other height). In other embodiments, the height 190a is otherwise suitably sized (e.g., more than 1.5 inches, less than 1 inch, or some other height) to accommodate the right upper cable guide 184a and the right lower cable guide 184b receiving a power cable.

[0050] According to an exemplary embodiment, the right cam 160a includes a plurality of apertures, holes, openings, etc. positioned throughout the right cam 160a to reduce the weight of the right cam 160a. In some embodiments, the right cam 160a includes more or fewer apertures than shown in FIG. 7a. In other embodiments, the right cam 160a does not include any apertures to reduce the weight.

[0051] Referring to FIGS. 8a and 8b, the left cam 160b is substantially similar and operates similarly to the right cam 160a and can be considered a mirror image of the right cam 160a. The left cam 160b includes a left upper drawstring journal 164c and a left lower drawstring journal 164d defining a width 170b, an upper surface 171c, a bottom surface 171d, a distance 172b, a radius 174b, a radial depth 176b, and an angle of separation 178b; a lip 168b; a left drawstring attachment post 180b; a left upper cable guide 184c (e.g., a second upper cable guide) and a left lower cable guide 184d (e.g., a second lower cable guide) defining a height 190b; and a left upper power cable post 188c and a left lower power cable post 188d.

[0052] Referring to FIG. 9, the drawstring 124 is shown, according to an exemplary embodiment. The drawstring 124 includes a center portion 200, a left loop portion 204 that forms a loop (e.g., a hoop, a closed curve) left of the center portion 200 of the drawstring 124, and a right loop portion 208 that forms a loop (e.g., a hoop, a closed curve) right of the center portion 200 of the drawstring 124. It should be understood that the terms “center,”“left,” and “right” are merely used to describe the orientation of various elements in the FIGURES. In other words, the terms “center,”“left,” and “right” used herein are for the purpose of description only and should not be regarded as limiting.

[0053] The center portion 200 may be a connecting portion of the drawstring 124 that connects the left loop portion 204 and the right loop portion 208 to each other. In other words, the center portion 200 is positioned laterally between the left loop portion 204 and the right loop portion 208 such that the left loop portion 204 and the right loop portion 208 are spaced apart from each other. Generally, the left loop portion 204 engages with the left cam 160b and is received within the left upper drawstring journal 164c and the left lower drawstring journal 164d, the right loop portion 208 engages with the right cam 160a and is received within the right upper drawstring journal 164a and the right lower drawstring journal 164b. The center portion 200 of the drawstring 124 extends in a lateral direction across the center rail 110 from the left cam 160b to the right cam 160a. The center portion 200 provides a section of the drawstring 124 to nock (e.g., selectively couple, load) the projectile thereto. For example, during operation of the crossbow 100 after the drawstring 124 is in a drawn (e.g., cocked) position, a user can provide the nock of a projectile over a length (e.g., a portion, an area, a region, a segment) of the center portion 200 such that the nock of the projectile is removably coupled to the center portion 200 of the drawstring 124. As the drawstring 124 moves from the drawn (e.g., cocked) position to the released (e.g., uncocked, undrawn) position and ultimately reaches the released position, the nock will separate from the center portion 200 of the drawstring 124 and the projectile will travel from the distal end 106 of the crossbow 100 (e.g., in a down-range direction toward a target).

[0054] Referring to FIGS. 10A and 10B, the drawstring 124 (e.g., the center portion 200, the left loop portion 204, the right loop portion 208) may be manufactured from a plurality of strings (e.g., strands, fibers, ropes, yarn), shown as inner strings 212. In some embodiments, the drawstring 124 is manufactured from a number of inner strings 212 that is between 10 and 22. In other embodiments, the drawstring 124 is manufactured from fewer than 10 inner strings 212 (e.g., 9 inner strings 212, 7 inner strings 212, 5 inner strings 212, or some other number of inner strings 212) or more than 22 inner strings 212 (e.g., 23 inner strings 212, 25 inner strings 212, 27 inner strings 212, or some other number of inner strings 212). Each inner string 212 has a diameter. Each inner string 212 of the drawstring 124 can include a substantially identical diameter. In other embodiments, the inner strings 212 of the drawstring 124 include two or more different diameters. Further, the diameter of each inner string 212 can remain substantially (e.g., ±95%) continuous over a length of the inner string 212 (e.g., from end to end). In other embodiments, the diameter of each inner string 212 can vary over a length of the inner string 212 (e.g., have a thicker portion and a thinner portion). The number of inner strings 212 may affect the thickness (e.g., diameter) of the drawstring 124. For example, manufacturing the drawstring 124 from a smaller number of inner strings 212 may reduce the thickness of the drawstring 124. The number of inner strings 212 may affect the strength (e.g., deformation resistance, tensile strength, elasticity) of the drawstring 124. For example, manufacturing the drawstring 124 from a larger number of inner strings 212 may increase the strength of the drawstring 124. Further, the diameter of inner strings 212 can affect the thickness (e.g., diameter), strength, or flexibility of the drawstring 124.

[0055] As shown in FIG. 10A, the inner strings 212 are not twisted, but instead form a bundle of inner strings 212 that are substantially aligned in an axial direction. For example, each of the inner strings 212 includes an axis, shown as string axis S, that can be substantially parallel (e.g., ±15° from parallel) with string axes S of each of the other inner strings 212. In particular, before the opposing ends of the inner strings 212 are joined together to create a continuous loop 220 as is discussed in detail below with reference to FIG. 11, among others, each of the inner strings 212 can be a substantially longitudinal string having a string axis S that is substantially parallel to the string axes S of each of the other inner strings 212. When the opposing ends of the inner strings 212 are joined together to form a continuous loop 220, as discussed below with reference to FIG. 11, each individual inner string 212 can extend along a path that is substantially identical in size and shape to paths along which all other inner strings 212 extend. In various embodiments, the inner strings 212 are substantially aligned and not twisted relative to each other or relative to some common axis. For example, the group of inner strings 212 can include an axis (e.g., a central axis running through the entire bundle of inner strings 212, a central axis of the drawstring 124), shown as common axis CA. Likewise, the group of inner strings 212 can extend along a path (e.g., a circular path, an ovular path, a curvilinear path). Each of the individual inner strings 212 of the group of inner strings 212 can have an individual string axis S that is substantially aligned (e.g., substantially parallel) with the common axis CA of the group of inner strings 212. Likewise, each of the individual inner strings 212 extends along a path that is substantially aligned (e.g., substantially identical in size and shape) with the path along which the entire group of inner strings 212 extends. The group of substantially aligned inner strings 212 (e.g., parallel string axes S, extending along a substantially identical shape) collectively form the core 216.

[0056] As shown in FIG. 10B, the inner strings 212 are twisted (e.g., rotated about an axis, coiled around common axis CA, strand twisted, wound, wrapped, plied, etc.) to collectively form a core 216 of the drawstring 124. For example, “twisting” may refer to the inner strings 212 being collectively (e.g., as a bundle or group of inner strings 212) twisted around a central axis of the drawstring 124 (e.g., an axis running axially through a center of the drawstring 124) or the common axis CA of the core 216. More specifically, the inner strings 212 can be twisted helically or according to some other three-dimensional path about a central axis of the drawstring 124. Likewise, the inner strings 212 can be twisted such that the string axis S of each of the inner strings 212 wrap around the common axis CA of the group of inner strings 212 (e.g., around the common axis CA of the core 216) along the length of the core 216. By way of another example, “twisting” may refer to the inner strings 212 being wrapped around each another in a specific pattern (e.g., braided, plied, or some other pattern). In some embodiments, the inner strings 212 are twisted between 7 and 12 twists per foot of core 216. For example, if the length of the core 216 is four feet long, the inner strings 212 may be twisted between 28 and 48 times (e.g., between 28 and 48 revolutions, cycles, twists, etc.). In some embodiments, the inner strings 212 are twisted less than 7 twists per foot (e.g., 6 twists per foot, 5 twists per foot, etc.) or more than 12 twists per foot (e.g., 13 twists per foot, 15 twists per foot, etc.). In some embodiments, to twist the inner strings 212 and form the core 216, a first end of each inner string 212 (e.g., the first end of all inner strings 212 within the core 216) may be held in place while second ends of each inner string 212 (e.g., the second end of all inner strings 212 within the core) are twisted around each other. In some embodiments, one twist is equivalent to one 360° revolution of the second ends of each inner string 212 around a central axis (e.g., a central axis of the core 216 or a central axis of the drawstring 124). The length of each inner string 212 may be substantially similar. In some embodiments, before twisting the inner strings 212 to form the core 216, the inner strings 212 are equally pre-tensioned such that each inner string 212 experiences a substantially similar tension when the drawstring 124 is installed on the crossbow 100 and when the crossbow 100 is in the released configuration, the drawn configuration, and / or any position or configuration therebetween. In such embodiments, the tension applied to the inner strings 212 may affect a torsional force condition (e.g., a torsional bias) between the left loop portion 204 and the right loop portion 208. For example, a decreased tension applied to the inner strings 212 during the formation of the core 216 (e.g., while twisting the inner strings 212. may decrease the induced torsional bias on the drawstring 124. In other embodiments, the inner strings 212 are otherwise joined together to form the core 216. For example, the inner strings 212 may be arranged twisting around each other or twisting around a common axis.

[0057] Referring to FIG. 11, after grouping the inner strings 212 together to form the core 216 (e.g., by twisting the inner strings 212 as shown in FIG. 10B or leaving the inner strings 212 untwisted as shown in FIG. 10A), opposite ends of the core 216 may be joined such that the core 216 forms a continuous loop 220. In some embodiments, the opposite ends of the core 216 are tied (e.g., knotted) together to form the continuous loop 220. In other embodiments, the opposite ends of the core 216 are spliced (e.g. interwoven) together to form the continuous loop 220. In yet other embodiments, the opposite ends of the core 216 are joined together to form the continuous loop 220 by way of another method, such as via some adhesive, some melting or fusing process, or some other process. In some embodiments, the opposite ends of the core 216 that are joined together are served (e.g., circumferentially wrapped by a serving material) to ensure the continuous loop 220 is not come un-done (e.g., the opposite ends of the core 216 separate).

[0058] Referring to FIG. 12, after joining opposite ends of the core 216 to form the continuous loop 220, the continuous loop 220 may be twisted such that a center section (e.g., center portion 200) of the continuous loop 220 is twisted and the left and right sides of the continuous loop 220 form separate loops (e.g., left loop portion 204 and right loop portion 208). For example, a first portion of the continuous loop 220 (e.g., a left-most portion) and a second portion of the continuous loop 220 (e.g., a right-most portion) can rotate about an axis relative to each other (e.g., in opposite directions) such that the remaining portions of the continuous loop 220 (e.g., portions of the continuous loop 220 between the first portion and the second portion) are twisted about an axis. In some embodiments, the continuous loop 220 is twisted between 7 and 12 twists per foot. In other embodiments, the continuous loop 220 is twisted less than 7 twists per foot (e.g., 6 twists per foot, 5 twists per foot, etc.) or more than 12 twists per foot (e.g., 13 twists per foot, 15 twists per foot, etc.). The continuous loop 220 may be twisted such that the center portion 200 is substantially centered between the left end portion (e.g., left end portion 270, terminal portion, looped end, outermost portion, or other end portion) of the left loop portion 204 and the right end portion (e.g., right end portion 266, terminal portion, looped end, outermost portion, or other end portion) of the right loop portion 208. The twisted center portion 200 may be formed when the left and right sides of the continuous loop 220 are twisted. For example, and as shown in FIG. 12, the left side of the continuous loop 220 is twisted clockwise (when viewed from a left side view), and the right side of the continuous loop 220 is twisted clockwise (when viewed from a right side view) to form the center portion 200. In other embodiments, the left side of the continuous loop 220 is twisted counterclockwise (when viewed from a left side view), and the right side of the continuous loop 220 is twisted counterclockwise (when viewed from a right side view) to form the center portion 200. In some embodiments, after joining opposite ends of the core 216 to form the continuous loop 220, the continuous loop 220 can remain untwisted. Put another way, the continuous loop 220 need not be subject to any twisting process or operation. In such embodiments, the step of forming the drawstring 124 shown in FIG. 12 may be omitted such that the center portion 200, the left loop portion 204, and the right loop portion 208 of the untwisted drawstring 124 shown in FIG. 11 are served (discussed below with reference to FIGS. 13-15) in a first serving process and a second serving process.

[0059] Referring to FIG. 13, at least a portion of the center portion 200, the left loop portion 204, and the right loop portion 208 are served (e.g., bound, wrapped, etc.) with a serving material (e.g., strand, fiber, rope, yarn, etc.), shown as serving material 224. The serving material 224 may be made from a material such as polyester, high-strength synthetic fibers, high modulus polyethylene, nylon, etc. In other embodiments, the serving material 224 is made from any other suitable material capable of resisting large and repeated tensions, repeated abrasions, moisture, creep, deformation, etc. The process of serving may include circumferentially wrapping the serving material 224 around an outer surface of the continuous loop 220 (e.g., around the center portion 200, the left loop portion 204, and the right loop portion 208). In some embodiments, the serving material 224 (or a spool holding the serving material 224) is tensioned when the serving material 224 is served around the core 216. In such embodiments, the tension applied to the serving material 224 may affect a torsional force condition (e.g., a torsional bias) between the left loop portion 204 and the right loop portion 208. For example, a decreased tension applied to the serving material 224 during the serving of the core 216 (e.g., while wrapping the serving material 224 around the center portion 200, the left loop portion 204, and the right loop portion 208) may decrease the induced torsional bias on the drawstring 124. After serving, the serving material 224 may substantially cover (e.g., surround, encompass, envelop, etc.) the inner strings 212 comprising the continuous loop 220 (e.g., the core 216).

[0060] According to an exemplary embodiment shown in FIG. 13, the serving material 224 is served around at least a portion of the left loop portion 204 and around at least a portion of the right loop portion 208. The serving material 224 may be served in a first serving direction, shown as first direction 228, and / or in a second serving direction, shown as second direction 232, opposite the first direction 228 around the left loop portion 204 and the right loop portion 208. For example, and as shown in FIG. 13, the left loop portion 204 may be served using the serving material 224 starting at a location proximate the center portion 200, serving in the first direction 228 around the left loop portion 204, and ending at a location proximate the center portion 200. In such an example, the right loop portion 208 may be served using the serving material 224 starting at a location proximate the center portion 200, serving in the second direction 232 around the right loop portion 208, and ending at a location proximate the center portion 200. The left loop portion 204 and the right loop portion 208 are served independently. The first direction 228 in which the serving material 224 is served around the left loop portion 204 may be different (e.g., opposite) the second direction 232 in which the serving material 224 is served around the right loop portion 208. For example, the serving material 224 may be served in a clockwise direction (e.g., the first direction 228) around the left loop portion 204, and the serving material 224 may be served in a counterclockwise direction (e.g., the second direction 232) around the right loop portion 208. By way of another example, the serving material 224 may be served in a counterclockwise direction (e.g., the first direction 228) around the left loop portion 204, and the serving material 224 may be served in a clockwise direction (e.g., the second direction 232) around the right loop portion 208. In some embodiments, a girth hitch knot (e.g., a strap hitch, bale sling hitch, ring hitch) may be located between the left loop portion 204 and the right loop portion 208. For example, a girth hitch knot can be used to alter the serving direction such that the left loop portion 204 can be served in a direction that is opposite a direction that the right loop portion 208 is served while using a continuous strand (e.g., section, piece, etc.) of the serving material 224. The girth hitch knot can be positioned at a center of the center portion 200. In other embodiments, the girth hitch knot is positioned off-center of the center portion 200 (e.g., within less 10 mm to one side of the center of the center portion 200 or more than 10 mm to one side of the center of the center portion 200).

[0061] According to an exemplary embodiment shown in FIGS. 14 and 15, the serving material 224 is served around the core 216 prior to or without twisting the continuous loop 220 such that the center portion 200 is twisted. In other words, the serving material 224 served around the left loop portion 204 and the right loop portion 208 as shown in FIGS. 14 and 15 is served around the core 216 of the drawstring 124 shown in FIG. 11. As shown in FIGS. 14 and 15, the drawstring 124 is arranged such that the left loop portion 204 and the right loop portion 208 are substantially parallel with each other. During the serving process, the drawstring 124 may be arranged in this manner such that the serving material 224 is served around portions of the core 216 that are substantially straight (e.g., flat, not curved) and the center portion 200 is curved (e.g., not straight). For example, the left loop portion 204 and the right loop portion 208 are straight and substantially parallel with each other such that the serving material 224 is not served around the left loop portion 204 and the right loop portion 208 when the left loop portion 204 and the right loop portion 208 are curved (e.g., as shown in FIG. 12), and is rather served around the left loop portion 204 and the right loop portion 208 when the left loop portion 204 and the right loop portion 208 are substantially straight.

[0062] As shown in FIGS. 14 and 15, the serving material 224 is served around at least a portion of the left loop portion 204 and served around at least a portion of the right loop portion 208, such that the left loop portion 204 and the right loop portion 208 include portions (e.g., sections, lengths) that are unserved (e.g., not served with the serving material 224). As shown in FIGS. 14 and 15, the serving material 224 is served around a first served portion (e.g., a portion of the left upper portion 204a), a second served portion (e.g., a portion of the left end portion 270), and a third served portion (e.g., a portion of the left lower portion 204b) of the left loop portion 204, and served around a first served portion (e.g., a portion of the right upper portion 208a), a second served portion (e.g., a portion of the right end portion 266), and a third served portion (e.g., a portion of the right lower portion 208b) of the right loop portion 208. The left loop portion 204 includes a first unserved portion between the first served portion and the second served portion, and a second unserved portion between the second served portion and the third served portion. Similarly, the right loop portion 208 includes a first unserved portion between the first served portion and the second served portion, and a second unserved portion between the second served portion and the third served portion. In some embodiments, the left loop portion 204 and the right loop portion 208 (e.g., the various portions thereof) are served with the serving material 224 in one or more of the first direction 228 or the second direction 232. For example, as shown in FIG. 14, the first served portion of the left loop portion 204 may be served in the first direction 228, the second served portion of the left loop portion 204 may be served in the second direction 232, and the third served portion of the left loop portion 204 may be served in the second direction 232. Similarly, as shown in FIG. 14, the first served portion of the right loop portion 208 may be served in the second direction 232, the second served portion of the right loop portion 208 may be served in the first direction 228, and the third served portion of the right loop portion 208 may be served in the first direction 228. By way of another example, the various portions of the left loop portion 204 and the right loop portion 208 may be served in another combination of serving directions to maintain a neutrally balanced string assembly.

[0063] Referring to FIGS. 14 and 15, the seams (e.g., points) at which the serving material 224 starts or stops being applied to the left loop portion 204 and the right loop portion 208 are shown as serving ends 236. As shown in FIGS. 14 and 15, the left end portion 270 of the left loop portion 204 and the right end portion 266 of the right loop portion 208 are served with the serving material 224 such that the entirety of the left end portion 270 and the right end portion 266 are served (e.g., covered with the serving material 224). In other words, the left end portion 270 is served such that when the drawstring 124 is installed on the crossbow 100, the serving ends 236 of the serving around the left end portion 270 are not inline (e.g., not engaged) with the left drawstring attachment post 180b. Similarly, the right end portion 266 is served such that when the drawstring 124 is installed on the crossbow 100, the serving ends 236 of the serving around the right end portion 266 are not inline (e.g., not engaged) with the right drawstring attachment post 180a. For example, the left end portion 270 and the right end portion 266 may be served with the serving material 224 such that the serving ends 236 do not engage with the right drawstring attachment post 180a or the left drawstring attachment post 180b when the drawstring 124 is installed on the crossbow 100. If the serving ends 236 were to engage with the drawstring attachment posts 180, the rotation of the right cam 160a and the left cam 160b during operation of the crossbow 100 may cause damage to the drawstring 124 (e.g., the serving material 224, the inner strings 212 forming the core 216).

[0064] When serving a core of a bowstring (e.g., a drawstring, a power cable, etc.), a bias (e.g., a rotational biasing force, a torsional force) can be created within the bowstring that biases the bowstring in the direction that the core was served. For example, a bowstring may have a tendency to want to twist (e.g., rotate) in a particular direction, giving the bowstring a preloaded twisted form. By wrapping the serving material 224 around the left loop portion 204 and the right loop portion 208 in opposite directions, a material bias of both the left loop portion 204 and the right loop portion 208 can be in a direction towards the center portion 200 of the drawstring 124, such that any bias (e.g., torsional bias, rotational bias) in the left loop portion 204 created during the serving process counteracts any bias (e.g., torsional bias, rotational bias) in the right loop portion 208 created during the serving process, and vice versa. For example, serving the left loop portion 204 and the right loop portion 208 in opposing directions facilitates a construction of the drawstring 124 having substantially no rotational bias one direction or another. By way of another example, serving (i) a first portion of the left loop portion 204 and a second portion of the left loop portion 204 in opposing directions, and (ii) a first portion of the right loop portion 208 and a second portion of the right loop portion 208 in opposing directions facilitates a construction of the drawstring 124 having substantially no rotational bias one direction or another (e.g., to maintain a neutrally balanced drawstring assembly). In other words, the left loop portion 204 may include a first torsional bias force with a first magnitude and the right loop portion may include a second torsional bias force with a second magnitude that is substantially equal to the first magnitude of the first torsional bias force.

[0065] In some embodiments, the serving material 224 may be served in the first direction 228 around at least a portion of the left loop portion 204 such that the first direction 228 is opposite a direction that the inner strings 212 were twisted to form the core 216. Similarly, the serving material 224 may be served in the second direction 232 around at least a portion of the right loop portion 208 such that the second direction 232 is opposite a direction that the inner strings 212 were twisted to form the core 216. In this manner, serving the left loop portion 204 and the right loop portion 208 in directions that oppose the direction that the inner strings 212 were twisted to form the core 216 counteracts a bias (e.g., torsional bias, rotational bias) formed in the core 216 as a result of twisting the inner strings 212.

[0066] As shown in FIG. 16, after serving one or more portions of the left loop portion 204 and the right loop portion 208 (as discussed above with reference to FIGS. 13-15), the center portion 200 may be served using the serving material 224. As shown in FIG. 16, the drawstring 124 is rotated (e.g., about 90 degrees counterclockwise) after serving one or more portions of the left loop portion 204 and the right loop portion 208 and prior to serving the center portion 200. As such, the top and bottom portions of the center portion 200 are substantially straight (e.g., parallel with each other), and the left loop portion 204 and the right loop portion 208 are curved (e.g., arced, looped) to form left and right loops, respectively. In some embodiments, the serving material 224 used to serve the center portion 200 may at least partially overlap the serving material 224 used to serve the left loop portion 204 and the right loop portion 208. For example, the servings of the center portion 200 may overlap the servings of the left loop portion 204 and the right loop portion 208 by 0.1 inches to 0.25 inches. In other embodiments, the serving of the center portion 200 may overlap the servings of the left loop portion 204 and the right loop portion 208 by less than 0.1 inches (e.g., 0.075 inches, 0.05 inches, etc.) or more than 0.25 inches (e.g., 0.3 inches, 0.5 inches, etc.). In yet other embodiments, the serving of the center portion 200 and the servings of the left loop portion 204 and the right loop portion 208 may not overlap. For example, the center portion 200 may include a first served portion 200a and a second unserved portion 200b positioned (i) between the left loop portion 204 and the first served portion 200a and (ii) between the right loop portion 208 and the first served portion 200a. In such an example, the first served portion 200a may be about 3 inches (e.g., about 3.1 inches, about 3.2 inches, more than 3 inches, about 2.9 inches, about 2.8 inches, less than 3 inches, etc.) and the second unserved portion 200b may be about 1.375 inches (e.g., about 1.4 inches, more than 1.375 inches, about 1.35 inches, less than 1.375 inches, etc.). In some embodiments, after serving the one or more portions of the left loop portion 204 and the right loop portion 208 and prior to serving the center portion 200, the drawstring 124 my be twisted one or more times such that the continuous loop 220 is twisted and the left and right sides of the continuous loop 220 form separate loops (e.g., the left loop portion 204 and the right loop portion 208). For example, a first portion of the continuous loop 220 (e.g., a left-most portion) and a second portion of the continuous loop 220 (e.g., a right-most portion) can rotate about an axis relative to each other (e.g., in opposite directions) such that the remaining portions of the continuous loop 220 (e.g., portions of the continuous loop 220 between the first portion and the second portion) are twisted about an axis. In such embodiments, the twisted portion of the center portion 200 may be served with the serving material 224. In other embodiments, the center portion 200 is not twisted prior to being served.

[0067] According to an exemplary embodiment, the first served portion 200a of the center portion 200 is served such that the drawstring 124 has substantially no rotational bias one direction or another. For example, a left side of the center portion 200 may be served in a direction that is opposite a direction that a right side of the center portion 200 is served. For example, a girth hitch may be located substantially centered (e.g., within 10 mm of center) in a lateral direction along the center portion 200 such that the left side of the center portion 200 is served in a direction that is opposite a direction that the right side of the center portion 200 is served. In some embodiments, serving the left side and the right side of the center portion 200 in opposing directions facilitates a construction of the drawstring 124 (and the center portion 200) having substantially no bias (e.g., torsional bias, rotational bias) one direction or another. For example, the drawstring 124 can be substantially balanced so as to provide a neutral torsional force condition with substantially no torsional bias (e.g., a counteracting torsional bias) between the left loop portion 204 and the right loop portion 208. In some embodiments, the center portion 200 is served entirely in a single direction, thereby creating a bias (e.g., torsional bias, rotational bias) in the serving direction within the center portion 200. In such embodiments, the direction of the bias (e.g., torsional bias, rotational bias) is the same as a direction that the projectile launched from the crossbow 100 (e.g., a projectile nocked to the center portion 200 of the drawstring 124 and fired from the crossbow 100) has a tendency to rotate when launched (e.g., thrust, propelled, fired, released) from the crossbow 100. For example, the projectile launched from the crossbow 100 can include fletching (e.g., one or more vanes, feathers, or other stabilizing attachments) that cause the projectile rotate about a longitudinal axis of the projectile as the projectile is launched from the crossbow 100. In such embodiments, the center portion 200 can be served entirely in a single direction such that the direction of a bias (e.g., a torsional bias, a rotational bias) of the center portion 200 is substantially the same direction as the direction in which the projectile has a tendency to rotate after the projectile is launched from the crossbow 100.

[0068] In some embodiments, the type serving material 224 used to serve the left loop portion 204 and the right loop portion 208 may be different than the type of serving material 224 used to serve the center portion 200. For example, the type serving material 224 used to serve the left loop portion 204 and the right loop portion 208 may be an ultra-high-molecular-weight polyethylene serving having a 0.014 inch diameter. In other embodiments, the type serving material 224 used to serve the left loop portion 204 and the right loop portion 208 is of another suitable type having suitable dimensions. By way of another example, the type serving material 224 used to serve the center portion 200 may be a high modulus polyethylene serving having a 0.026 serving. In other embodiments, the type serving material 224 used to serve the center portion 200 is of another suitable type having suitable dimensions. In some embodiments, a portion of the drawstring 124 that does not contact (e.g., interface, rub, touch, engage with) any component of the crossbow 100 (e.g., a nock of a projectile, a drawstring journal 164, a drawstring attachment post 180, etc.) may not be served. In some embodiments, the type serving material 224 used to serve the left loop portion 204 and the right loop portion 208 is chosen such that an outer diameter of the left loop portion 204 and the right loop portion 208 is equal to or less than the radius 174 of the drawstring journal 164 (e.g., such that the left loop portion 204 and the right loop portion 208 can be received within the drawstring journals 164). In some embodiments, the type serving material 224 used to serve the center portion 200 is chosen such that an outer diameter of the center portion 200 can be received within a nock of the projectile.

[0069] As shown in FIGS. 5, 6, and 17-20, the drawstring 124 and power cables 250 are installed on the crossbow 100. Specifically, the crossbow 100 includes four power cables 250, including a first power cable 250a, a second power cable 250b, a third power cable 250c, and a fourth power cable 250d, with each one corresponding to a respective cable guide 184. In embodiments where the crossbow 100 has greater or fewer cable guides 184, the crossbow 100 can include correspondingly greater or fewer power cables 250. For example, the crossbow 100 may include one cable guide 184 and, correspondingly, one power cable 250. By way of another example, the crossbow 100 may include two cable guides 184 (e.g., a top cable guide 184 and a bottom cable guide 184) and, correspondingly, two power cables 250 (e.g., a top power cable 250 and a bottom power cable 250). Each power cable 250 includes a first end portion 254a, 254b, 254c, and 254d (e.g., terminal portion, looped end, outermost portion, or other end portion) that is configured to be coupled to (e.g., wrapped around, mounted at, etc.) the right cam 160a or the left cam 160b at right upper power cable post 188a, right lower power cable post 188b, left upper power cable post 188c, and left lower power cable post 188d, respectively. The right upper cable guide 184a, the right lower cable guide 184b, the left upper cable guide 184c, and the left lower cable guide 184d provide a path (e.g., a journal) about which a predetermined length of power cables 250a, 250b, 250c, and 250d can wrap about the right cam 160a or the left cam 160b, respectively. In some embodiments, the upper power cables (e.g., the first power cable 250a and the third power cable 250c) extend across the frame 102 and are attached to limb mountings 258c and 258a respectively. Similarly, lower power cables (e.g., the second power cable 250b and the fourth power cable 250d) extend across the frame 102 and are attached to limb mountings 258d and 258b, respectively. In some embodiments, two or more power cables 250 can correspond to each cable guide 184 of the crossbow 100 (e.g., in embodiments where each cable guide 184 receives, takes-up, lets-out, or otherwise engages with two or more power cable end portions 254). In some embodiments, a respective cam 160 (e.g., the right cam 160a and / or the left cam 160b) includes an opening (e.g., gap, aperture, hole) therein. In such embodiments, a respective power cable 250 may be routed through the opening of the respective cam 160 such that the respective power cable 250 engages with both a respective upper cable guide 184 and a respective lower cable guide 184 of the respective cam 160. For example, the right cam 160a may include an opening configured to receive the first power cable 250a such that the first power cable 250a engages with both the right upper cable guide 184a and the right lower cable guide 184b of the right cam 160a. In such an example, the first end portion 254a of the first power cable 250a may be split such that a first split end of the first power cable 250a engages with the right upper cable guide 184a and a second split end of the first power cable 250a engages with the right lower cable guide 184b. In such an example, the crossbow 100 may omit the third power cable 250c. By way of another example, the left cam 160b may include an opening configured to receive the third power cable 250c such that the third power cable 250c engages with both the left upper cable guide 184c and the left lower cable guide 184d of the left cam 160b. By way of yet another example, the right cam 160a may include an opening configured to receive the second power cable 250b such that the second power cable 250b engages with both the right upper cable guide 184a and the right lower cable guide 184b of the right cam 160a. By way of still another example, the left cam 160b may include an opening configured to receive the fourth power cable 250d such that the thi fourth power cable 250d engages with both the left upper cable guide 184c and the left lower cable guide 184d of the left cam 160b.

[0070] The right upper cable guide 184a, the right lower cable guide 184b, the left upper cable guide 184c, and the left lower cable guide 184d are configured to draw a predetermined length of the power cables 250a, 250b, 250c, and 250d onto the right upper cable guide 184a, the right lower cable guide 184b, the left upper cable guide 184c, and the left lower cable guide 184d when the string carrier 122 operates to pull the drawstring 124 to the cocked position (e.g., when the crossbow 100 is transitioned from the released configuration to the drawn configuration). This has the effect of drawing the free ends 152 of the limbs 150 inwardly against the resilient bias of the limbs 150 and stores potential energy in the limbs 150.

[0071] As shown in FIGS. 5, 6, and 17-20, the right and left upper cable guides 184a and 184c are configured such that power cables 250a and 250c cross the center rail 110 within an upper cable slide 260. The upper cable slide 260 is configured to be slidable in a longitudinal direction within an aperture of the string cover 120. Similarly, right and left lower cable guides 184b and 184d are configured such that power cables 250b and 250d cross the center rail 110 within a lower cable slide 262. The lower cable slide 262 is configured to be slidable in a longitudinal direction within an aperture of the frame 102 and positioned below the center rail 110. The upper cable slide 260 and the lower cable slide 262 provide a vertical separation between the upper power cables 250a and 250c and the lower power cables 250b and 250d that enables the power cables 250 to cross over the center rail 110 without interfering with the movement of string carrier 122 or a projectile within the space provided between center rail 110 and the string cover 120. This approach thereby facilitates the crossbow 100 to be more compact while still retaining desired functionality including helping to ensure that a balanced application of force is made.

[0072] Additionally, in this embodiment, by routing the power cables 250 directly from the cable guides 184 to the limb mountings 258, the predetermined length of the power cables 250 that is available for winding on the upper and lower cable guides 184 can be greater. By using a spiral or helical winding of the cable about the cable guides 184, it becomes possible to store a greater length of the power cables 250 on each of the cable guides 184, and to do so with greater radius of winding to reduce the stresses experienced by the power cables 250.

[0073] The drawstring 124 includes a right end portion 266 (e.g., a second end portion, the right end portion of the right loop portion 208, terminal portion, looped end, outermost portion, or other end portion) and a left end portion 270 (e.g., a first end portion, the left end portion of the left loop portion 204, terminal portion, looped end, outermost portion, or other end portion). The right end portion 266 is configured to be coupled to (e.g., wrapped around, mounted at, etc.) the right cam 160a at the right drawstring attachment post 180a. The drawstring 124 (e.g., the right loop portion 208) is configured to be routed along an outer circumference of the right cam 160a within the right drawstring journals 164a and 164b. For example, the right loop portion 208 may include a right upper portion 208a configured to wrap around the right cam 160a within the right upper drawstring journal 164a and a right lower portion 208b configured to wrap around the right cam 160a within the right lower drawstring journal 164b. In such an example, the right upper portion 208a and the right lower portion 208b of the right loop portion 208 may be substantially parallel with each other and with the rotation plane P. The right upper drawstring journal 164a and the right lower drawstring journal 164b provide a path (e.g., a journal) about which a predetermined length of the drawstring 124 can wrap about the right cam 160a.

[0074] The left end portion 270 of the drawstring 124 is configured to be coupled to (e.g., wrapped around, mounted at, etc.) the left cam 160b at the left drawstring attachment post 180b. The drawstring 124 (e.g., the left loop portion 204) is configured to be routed along an outer circumference of the left cam 160b within the left drawstring journals 164c and 164d. For example, the left loop portion 204 may include a left upper portion 204a configured to wrap around the left cam 160b within the left upper drawstring journal 164c and a left lower portion 204b configured to wrap around the left cam 160b within the left lower drawstring journal 164d. In such an example, the left upper portion 204a and the left lower portion 204b of the left loop portion 204 may be substantially parallel with each other and with the rotation plane P. The left upper drawstring journal 164c and the left lower drawstring journal 164d provide a path (e.g., a journal) about which a predetermined length of the drawstring 124 can wrap about the left cam 160b.

[0075] In the released configuration, the right loop portion 208 is let out of the right cam 160a (e.g., the right upper drawstring journal 164a and the right lower drawstring journal 164b) and routed in a lateral direction in a direction towards the frame 102. Similarly, the left loop portion 204 is let out of the left cam 160b (e.g., the left upper drawstring journal 164c and the left lower drawstring journal 164d) and routed in a lateral direction in a direction towards the frame 102. The center portion 200 extends between the right loop portion 208 and the left loop portion 204 in a lateral direction across the frame 102 and the center rail 110. In the released configuration, the center portion 200 a section of the drawstring 124 to nock (e.g., selectively couple, load, etc.) a projectile thereto.

[0076] Referring particularly to FIGS. 6, 19, and 20, the crossbow 100 is shown in the drawn configuration, with substantially a full portion of the predetermined length of the drawstring 124 let out from the right cam 160a and the left cam 160b. In such an embodiment, the center portion 200 may be retained by the string carrier 122 as the string carrier 122 translates in a direction towards the proximal end 116 of the crossbow 100, thereby transitioning the crossbow 100 to the drawn configuration. In the drawn configuration, the drawstring 124 is let out from the right cam 160a and the left cam 160b at tangent points 274a and 274b such that a cam gap 278 extends therebetween.

[0077] In the drawn configuration, the crossbow 100 is configured to fire a projectile, and the drawstring 124 is contained within the lateral boundaries provided by center rail 110 and the string cover 120. The string cover 120 may be sized to accommodate the cam gap 278 at a high end of a range of distances between the tangent points 274, so that the drawstring 124 may be contained within string cover 120. In such an embodiment, the string carrier 122 may capture a segment of the drawstring 124 (e.g., a segment of the center portion 200) that is smaller than the cam gap 278, thereby causing the drawstring 124 to form a V-shaped configuration in the drawn configuration with the narrow portion of the “V” near the proximal end 116. Accordingly, in some embodiments, the string cover 120 may be optionally narrower near the proximal end 116. In the drawn configuration, the tension forces on the drawstring 124 on opposite sides of the string carrier 122 (e.g., the left loop portion 204 and the right loop portion 208) are substantially the same.

[0078] According to an exemplary embodiment, when the crossbow 100 is in the drawn configuration, an angle formed between the left loop portion 204 and the projectile axis A is substantially similar to an angle formed between the right loop portion 208 and the projectile axis A when viewed from the top view.

[0079] When drawstring 124 is released by string carrier 122 (e.g., in response to a user engaging the trigger 134), potential energy is released from the limbs 150 as the limbs 150 separate (e.g., move away from the frame 102). This separation compels the right cam 160a and the left cam 160b to rotate rapidly to let out lengths of the power cables 250 stored along the cable guides 184. This, in turn causes the predetermined lengths of the drawstring 124 to be wound onto the drawstring journals 164. For example, in response to the drawstring 124 being released from the string carrier 122, the right cam 160a rotates in a clockwise direction about the right cam axis B and the left cam 160b rotates in a counterclockwise direction about the left cam axis C (when viewed from FIGS. 18 and 20). In turn, the right upper cable guide 184a lets out the first power cable 250a, the right lower cable guide 184b lets out the second power cable 250b, the left upper cable guide 184c lets out the third power cable 250c, and left lower cable guide 184d lets out the fourth power cable 250d. Additionally, in turn, the right upper portion 208a of the right loop portion 208 is taken up (e.g., received within, wound about, etc.) by the right upper drawstring journal 164a, the right lower portion 208b of the right loop portion 208 is taken up by the right lower drawstring journal 164b, the left upper portion 204a of the left loop portion 204 is taken up by the left upper drawstring journal 164c, and the left lower portion 204b of the left loop portion 204 is taken up by the left lower drawstring journal 164d.

[0080] During firing operations, as the potential energy is released from the limbs 150 as the limbs 150 separate, the cam gap 278 between the tangent point 274 increases. For example, during firing, the right limbs 150a and 150b laterally separate from the left limbs 150c and 150d. Because the right cam 160a and the left cam 160b are mounted to the limbs 150, the right cam 160a and the left cam 160b also laterally separate, thereby laterally displacing the tangent points 274 and increasing the cam gap 278. Substantially simultaneously, the right cam 160a and the left cam 160b rotate to draw portions of drawstring 124 onto the drawstring journal 164. In some embodiments, the inertia and drag of the projectile causes the drawstring 124 to maintain a V shape as this occurs, the distance between the vertex of the V and the tangent points 274 closes as the projectile is thrust along the center rail 110 in a direction downrange toward the distal end 106.

[0081] In some embodiments, the drawstring 124 is engaged with a first pulley assembly (e.g., a right pulley assembly, a first cam assembly, a first lever assembly) and a second pulley assembly (e.g., a left pulley assembly, a second cam assembly, a second lever assembly). The at least one power cables 250 may be engaged with at least one of the pulley assemblies. For example, the crossbow 100 may include one power cable 250 engaged with the first pulley assembly and one power cable 250 engaged with the second pulley assembly. The first pulley assembly and the second pulley assembly may be rotatably mounted (e.g., rotatably coupled, rotatably secured) to the right limbs 150a and 150b and the left limbs 150c and 150d, respectively, and can be configured to rotate about a first pulley assembly axis and a second pulley assembly axis, respectively. The first and second pulley assemblies may each include a pulley coupled to a power cable journal via a lever arm. The pulley of each pulley assembly may be configured to rotate about a pulley axis that is parallel with and spaced apart from the respective pulley assembly axis. The lever arm of the pulley assembly may be configured to rotate about the pulley assembly axis. Each pulley may move along an arc about the respective pulley assembly axis as the lever rotates about the pulley assembly axis, which occurs during operation of the crossbow 100 as the drawstring 124 moves between the released position to the drawn position. As the lever rotates about the pulley assembly axis, the pulley rotates about the pulley axis.

[0082] Referring to FIG. 21, a method of manufacturing a drawstring (e.g., drawstring 124) is shown as method 300, according to an exemplary embodiment. The method 300 includes steps 302-316. Each of steps 302-316 are optional. For example, the method 300 can include some, but not all, of steps 302-316. Further, the steps 302-316 need not be performed in the order depicted in FIG. 21.

[0083] At step 302, a plurality of inner strings (e.g., inner strings 212) and serving material (e.g., serving material 224) are provided. At step 304, the inner strings are grouped together to form a core (e.g., core 216) of the drawstring. For example, the core can be formed by grouping multiple inner strings 212 together to form a core having inner string substantially aligned (e.g., axially aligned or extending along a similar path) as depicted in FIG. 10A and as discussed above. In other embodiments, the inner strings can be twisted to relative to each other or relative to some common axis of the bundle of inner strings, as depicted in FIG. 10B and as discussed above. In various embodiments, each of the plurality of inner strings are substantially the same length. In some embodiments, each of the plurality of inner strings are equally pre-tensioned while being twisted such that each inner string experiences a substantially similar tension when the drawstring is installed on the crossbow and when the crossbow is in the released configuration, the drawn configuration, and / or any position or configuration therebetween. In some embodiments, the inner strings are not twisted relative to each other.

[0084] At step 306, a continuous loop is formed. For example, step 306 can include joining opposite ends of the core to form a continuous loop (e.g., continuous loop 220). The opposite ends of the core may be tied together, spliced together, fused or melted together, joined by some adhesive, or otherwise bonded to form the continuous loop.

[0085] At step 308, a center portion, a left loop portion, and a right loop portion are formed. For example, the continuous loop can be twisted such that a center portion (e.g., center portion 200) of the continuous loop is twisted, a left side of the continuous loop forms a left loop portion (e.g., left loop portion 204), and a right side of the continuous loop forms a right loop portion (e.g., right loop portion 208). In some embodiments, step 308 is omitted such that the continuous loop is untwisted.

[0086] At step 310, the left loop portion is served with a serving material. For example, the left loop portion can be served in a first direction (e.g., first direction 228) using a first serving material.

[0087] At step 312 the right loop portion is served using a serving material. For example, the right loop portion can be served in a second direction (e.g., second direction 232) using a second serving material. The second direction is opposite the first direction. For example, the first serving material may be served around the entirety of the left loop portion in the first direction that is clockwise, and the second serving material may be served around the entirety of the right loop portion in the second direction that is counterclockwise (e.g., clockwise and counterclockwise being opposite directions). The second serving material served on the right loop portion can be the same as or different than the first serving material served on the left loop portion. In some embodiments, step 308 is performed after steps 310 and 312. For example, after serving the left loop portion and the right loop portion, the continuous loop may be twisted such that a left portion of the drawstring forms the left loop portion, a right portion of the drawstring forms the right loop portion, and the twisted portion of the drawstring forms the center portion.

[0088] At step 314, the center portion is served using a third serving material. In some embodiments, the center portion is served such that a left side of the center portion is served in an opposite direction that a right side of the center portion is served in. In some embodiments, the serving of the center portion overlaps at least a portion of the servings of the left and right loop portions. In some embodiments, the first serving material served on left loop portion and the second serving material served on the right loop portion are different than the third serving material used to serve the center portion. In other embodiments, one or more of the first serving material served on left loop portion and the second serving material served on the right loop portion are the same as than the third serving material used to serve the center portion. After completing steps 302-314, a drawstring (e.g., drawstring 124) is created. In some embodiments, serving the left loop portion and the right loop portion in opposing directions facilitates a construction of the drawstring having substantially no rotational bias one direction or another.

[0089] At step 316, the drawstring created after steps 302-314 is operatively coupled to a cam assembly (e.g., cam assembly 108) included in a crossbow (e.g., crossbow 100). The drawstring is coupled to the cam assembly such that drawing the drawstring rotates the cam assembly and transitions the crossbow between a released configuration and a drawn configuration. For example, a left end portion of the left loop portion is wrapped around a left drawstring attachment post (e.g., left drawstring attachment post 180b) of a dual track left cam (e.g., left cam 160b) and routed along an outer circumference of the dual track left cam within each track (e.g., left upper drawstring journal 164c and left lower drawstring journal 164d). The dual track left cam routes the left loop portion in a direction towards a center rail of the crossbow. Similarly, a right end portion of the right loop portion is wrapped around a right drawstring attachment post (e.g., right drawstring attachment post 180a) of a dual track right cam (e.g., right cam 160a) and routed along an outer circumference of the dual track right cam within each track (e.g., right upper drawstring journal 164a and right lower drawstring journal 164b). The dual track right cam routes the right loop portion in a direction towards the center rail of the crossbow. The center portion is configured to extend in a lateral direction across the center rail and between the left and right loop portions.

[0090] Referring to FIG. 22, a method of manufacturing a drawstring (e.g., drawstring 124) is shown as method 350, according to an exemplary embodiment. The method 350 includes steps 352-364. Each of steps 352-364 are optional. For example, the method 350 can include some, but not all, of steps 352-364. Further, the steps 352-364 need not be performed in the order depicted in FIG. 22.

[0091] At step 352, a core material (e.g., the core 216) and serving material (e.g., serving material 224) are provided. For example, the core can be formed by grouping multiple inner strings together to form a core having inner string substantially aligned (e.g., axially aligned or extending along a similar path) as depicted in FIG. 10A and as discussed above. In some embodiments, the inner strings can be twisted to relative to each other or relative to some common axis of the bundle of inner strings, as depicted in FIG. 10B and as discussed above. In other embodiments, the inner strings are not twisted relative to each other.

[0092] At step 354, a continuous loop is formed. For example, step 306 can include joining opposite ends of the core material to form a continuous loop (e.g., continuous loop 220). The opposite ends of the core material may be tied together, spliced together, fused or melted together, joined by some adhesive, or otherwise bonded to form the continuous loop including a center portion (e.g., center portion 200), a left loop portion (e.g., left loop portion 204), and a right loop portion (e.g., right loop portion 208).

[0093] At step 356, the continuous loop is twisted. For example, the continuous loop may be twisted such that the center portion of the continuous loop is twisted, the left loop portion of the continuous loop forms a left loop, and the right loop portion of the continuous loop forms a right loop. In some embodiments, step 356 is omitted such that the continuous loop is not twisted.

[0094] At step 358, at least a portion of the left loop portion is served with the serving material in at least one direction. For example, a first portion of the left loop portion may be served and a second portion of the left loop portion may be served such that the left loop portion includes at least one unserved portion. In such an example, the first portion may be served in a first serving direction (e.g., first direction 228) and the second portion may be served in a second serving direction (e.g., second direction 232) opposite the first direction.

[0095] At step 360, at least a portion of the right loop portion is served with the serving material in at least one direction. For example, a first portion of the right loop portion may be served and a second portion of the right loop portion may be served such that the right loop portion includes at least one unserved portion. In such an example, the first portion may be served in a first serving direction (e.g., first direction 228) and the second portion may be served in a second serving direction (e.g., second direction 232) opposite the first direction.

[0096] At steps 358 and 360, the drawstring may be arranged such that the portions of the drawstring being served (e.g., the left loop portion and the right loop portion) are substantially straight (and the center portion is curved). Further, at steps 358 and 360, the at least one portions of the left loop portion and the right loop portion are served in a manner such that the drawstring has substantially no rotational bias one direction or another. In other words, the drawstring is served to maintain a neutrally balanced string assembly.

[0097] At step 362, the center portion of the drawstring is twisted. By way of example, the center portion may be twisted in addition to the twists applied at step 356. By way of another example, in embodiments where step 356 is omitted, the center portion is twisted for the first time. In some embodiments, step 362 is omitted such that the center portion is not twisted. By way of example, the continuous loop may be twisted at step 356 and the center portion may not be twisted more at step 362. By way of another example, the continuous loop may not be twisted at step 356 and the center portion may not be twisted at step 362 such that the center portion remains entirely not twisted.

[0098] At step 364, at least a portion of the center portion is served with the serving material in at least one direction. The drawstring may be rotated (e.g., about 90 degrees counterclockwise) after serving one or more portions of the left loop portion and the right loop portion and prior to serving the center portion. As such, the top and bottom portions of the center portion may be substantially straight (e.g., parallel with each other), and the left loop portion and the right loop portion may be curved (e.g., arced, looped) to form left and right loops, respectively. The center portion may be served to include a first served portion and a second unserved portion positioned (i) between the left loop portion and the first served portion and (ii) between the right loop portion and the first served portion. In some embodiments, the serving added to the center portion is added in one or more directions to counteract the rotational bias created within the drawstring due to the twists in the core, the serving directions of the left loop portion, the serving directions of the right loop portion, among other factors. Serving the center portion in this manner facilitates providing a drawstring that is substantially balanced so as to provide a neutral torsional force condition with substantially no torsional bias (e.g., a counteracting torsional bias) between the left loop portion and the right loop portion. In some embodiments, the center portion is served (e.g., entirely in a single direction) to create a bias (e.g., torsional bias, rotational bias) in the serving direction within the center portion. In such embodiments, the direction of the bias (e.g., torsional bias, rotational bias) is the same as a direction that the projectile launched from the crossbow (e.g., a projectile nocked to the center portion of the drawstring and fired from the crossbow) has a tendency to rotate when launched (e.g., thrust, propelled, fired, released) from the crossbow. For example, the projectile launched from the crossbow can include fletching (e.g., one or more vanes, feathers, or other stabilizing attachments) that cause the projectile rotate about a longitudinal axis of the projectile as the projectile is launched from the crossbow. In such embodiments, the center portion can be served such that the direction of a bias (e.g., a torsional bias, a rotational bias) of the center portion is substantially the same direction as the direction in which the projectile has a tendency to rotate after the projectile is launched from the crossbow. After completing steps 352-364, a drawstring (e.g., drawstring 124) is created.

[0099] As utilized herein with respect to numerical ranges, the terms “approximately,”“about,”“substantially,” and similar terms generally mean + / −10% of the disclosed values. When the terms “approximately,”“about,”“substantially,” and similar terms are applied to a structural feature (e.g., to describe its shape, size, orientation, direction, etc.), these terms are meant to cover minor variations in structure that may result from, for example, the manufacturing or assembly process and are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.

[0100] It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

[0101] The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using one or more separate intervening members, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.

[0102] References herein to the positions of elements (e.g., “top,”“bottom,”“above,”“below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.

[0103] Although the figures and description may illustrate a specific order of method steps or operations, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above.

[0104] It is important to note that the construction and arrangement of the projectile launcher as shown in the various exemplary embodiments is illustrative only. Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.

Examples

Embodiment Construction

[0027]Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

[0028]Referring to FIGS. 1-5, a crossbow (e.g., bow, projectile launcher, etc.), shown as crossbow 100, is shown in a released configuration (e.g., de-cocked position, fired position, un-drawn position, etc.). According to an exemplary embodiment, the crossbow 100 includes a frame (e.g., rail, chassis, body, shell, or other frame member), shown as frame 102, a limb assembly 104 coupled to the frame 102 at a distal end 106 (e.g., front end, down-range end) of the crossbow 100, and a cam assembly 108 coupled to the limb assembly 104.

[0029]The frame102 includes a center rail 110 configured to support ...

Claims

1. A crossbow comprising:a frame;a limb assembly coupled to the frame and including:a first upper limb;a first lower limb;a second upper limb; anda second lower limb;a drawstring including a left loop portion, a right loop portion, and a center portion extending between the left loop portion and the right loop portion; anda cam assembly rotatably coupled with the limb assembly and including:a first cam rotatable about a first cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the right loop portion of the drawstring, wherein the upper drawstring journal of the first cam and the lower drawstring journal of the first cam are vertically offset from each other; anda second cam rotatable about a second cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the left loop portion of the drawstring, wherein the upper drawstring journal of the second cam and the lower drawstring journal of the second cam are vertically offset from each other.

2. The crossbow of claim 1, further comprising:the right loop portion attached to the first cam via a first attachment post, the first attachment post extending from an outer radial surface of the first cam; andthe left loop portion attached to the second cam via a second attachment post, the second attachment post extending from an outer radial surface of the second cam.

3. The crossbow of claim 1, wherein the right loop portion includes a first torsional bias force and the left loop portion includes a second torsional bias force, the first torsional bias force acting in a direction opposite the second torsional bias force.

4. The crossbow of claim 3, wherein the first torsional bias force has a first magnitude that is substantially equal to a second magnitude of the second torsional bias force.

5. The crossbow of claim 1, wherein the drawstring is substantially balanced to provide a neutral condition with substantially no counteracting torsional bias between the left loop portion and the right loop portion.

6. The crossbow of claim 1, wherein the drawstring is configured to move from a drawn position to a released position to launch a projectile from the crossbow, the projectile including a longitudinal axis and a plurality of vanes configured to cause the projectile to rotate in a first direction about the longitudinal axis as the projectile is launched from the crossbow,wherein, during operation of the crossbow as the drawstring moves from the drawn position to the released position, the center portion of the drawstring momentarily rotates in the first direction.

7. The crossbow of claim 1, further comprising:the right loop portion including a first serving twisted at least partially around the right loop portion in a first direction; andthe left loop portion including a second serving twisted at least partially around the left loop portion in a second direction;wherein the second direction is opposite the first direction.

8. The crossbow of claim 1, further comprising:the right loop portion including a first serving twisted at least partially around the right loop portion in a first direction;the left loop portion including a second serving twisted at least partially around the left loop portion in a second direction;wherein the second direction is in the same direction as the first direction.

9. The crossbow of claim 1, wherein:the first cam includes:a first upper cable guide extending from a top surface of the first cam along the first cam axis; anda first lower cable guide extending from a bottom surface of the first cam along the first cam axis;wherein the upper drawstring journal of the first cam and the lower drawstring journal of the first cam are positioned vertically between the first upper cable guide and the first lower cable guide; andthe second cam includes:a second upper cable guide extending from a top surface of the second cam along the second cam axis; anda second lower cable guide extending from a bottom surface of the second cam along the second cam axis;wherein the upper drawstring journal of the second cam and the lower drawstring journal of the second cam are positioned vertically between the second upper cable guide and the second lower cable guide.

10. A cam assembly comprising:a drawstring including a left loop portion, a right loop portion, and a center portion extending between the left loop portion and the right loop portion;a first cam rotatable about a first cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the right loop portion of the drawstring, the first cam including:a first upper cable guide extending from a top surface of the first cam along the first cam axis; anda first lower cable guide extending from a bottom surface of the first cam along the first cam axis,wherein the upper drawstring journal of the first cam and the lower drawstring journal of the first cam are positioned vertically between the first upper cable guide and the first lower cable guide; anda second cam rotatable about a second cam axis and including an upper drawstring journal and a lower drawstring journal configured to receive the left loop portion of the drawstring, the second cam including:a second upper cable guide extending from a top surface of the second cam along the second cam axis; anda second lower cable guide extending from a bottom surface of the second cam along the second cam axis;wherein the upper drawstring journal of the second cam and the lower drawstring journal of the second cam are positioned vertically between the second upper cable guide and the second lower cable guide.

11. The cam assembly of claim 10, further comprising:the right loop portion attached to the first cam via a first attachment post, the first attachment post extending from an outer radial surface of the first cam; andthe left loop portion attached to the second cam via a second attachment post, the second attachment post extending from an outer radial surface of the second cam.

12. The cam assembly of claim 10, wherein the right loop portion includes a first torsional bias force and the left loop portion includes a second torsional bias force, the first torsional bias force acting in a direction opposite the second torsional bias force.

13. The cam assembly of claim 12, wherein the first torsional bias force has a first magnitude that is substantially equal to a second magnitude of the second torsional bias force.

14. The cam assembly of claim 10, wherein the drawstring is substantially balanced to provide a neutral condition with substantially no counteracting torsional bias between the left loop portion and the right loop portion.

15. The cam assembly of claim 10, wherein the drawstring is configured to move from a drawn position to a released position to launch a projectile nocked to the center portion of the drawstring, the projectile including a longitudinal axis and a plurality of vanes configured to cause the projectile to rotate in a first direction about the longitudinal axis as the projectile separates from the center portion of the drawstring,wherein, during operation of a crossbow as the drawstring moves from the drawn position to the released position, the center portion of the drawstring momentarily rotates in the first direction.

16. The cam assembly of claim 10, further comprising:the right loop portion including a first serving twisted at least partially around the right loop portion in a first direction;the left loop portion including a second serving twisted at least partially around the left loop portion in a second direction;wherein the second direction is opposite the first direction.

17. The cam assembly of claim 10, wherein the first cam includes an attachment post detachably coupled to a side of the first cam, wherein the right loop portion of the drawstring is coupled to the first cam via the attachment post.

18. A method of manufacturing a drawstring, the method comprising:providing a plurality of inner strings and serving material;grouping the plurality of inner strings together to form a core of the drawstring;joining opposite ends of the core to form a continuous loop;twisting the continuous loop such that a center portion of the continuous loop is twisted, a left side of the continuous loop forms a left loop portion, and a right side of the continuous loop forms a right loop portion;serving at least a portion of the left loop portion using the serving material;serving at least a portion of the right loop portion using the serving material; andserving at least a portion of the center portion using the serving material,wherein a first portion of the left loop portion is served in a first direction using the serving material, wherein a second portion of the left loop portion is served in a second direction using the serving material, wherein a first portion of the right loop portion is served in the first direction using the serving material, wherein a second portion of the right loop portion is served in the second direction using the serving material, and wherein the first direction is opposite the second direction.

19. The method of claim 18, wherein serving at least the portion of the left loop portion and serving at least the portion of the right loop portion occurs during a first serving step, wherein serving at least the portion of the center portion occurs during a second serving step, and wherein the drawstring is rotated between the first serving step and the second serving step.

20. The method of claim 19, wherein the left loop portion and the right loop portion are substantially straight in the first serving step, and wherein the center portion is substantially straight in the second serving step.

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