Reciprocating impact tool with impact control

Abstract

A power tool includes a motor, a spindle defining a first end with a slot, and a crankshaft including a counterweight and a crankpin, the counterweight and crankpin being rotatable about a crank axis by the motor such that at least one of the counterweight and the crankpin rotates through the slot. The spindle includes a second end opposite to the first end and defines a third distance between the first and second ends of the spindle. The spindle further includes an anvil seat portion between the first and second ends and defines a fourth distance between the anvil seat portion and the first end of the spindle. The power tool further includes an anvil received in the spindle, and the anvil seat defines a drill bit seat portion configured to receive a tool drill bit.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Patent Application No. 19 / 199,272, filed May 5, 2025, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0003] Power tools (such as chisels, rotary hammers, pneumatic hammers, drills, air chisels, etc.) can be used to drill or impact workpieces with a drill bit (e.g., to remove material from a workpiece). The output unit of the power tool may include an impact mechanism that provides power to translate the drill bit in an axial (i.e., linear) direction. For example, in some applications, the impact mechanism may include an impact member that translates in the axial direction to transmit the impact to the tool drill bit (e.g., via an anvil). Summary of the Invention

[0004] According to one aspect of this disclosure, a power tool may include a motor, a spindle defining a first end having a slot, and a crankshaft including a counterweight and a crank pin. The crankshaft may be rotated about a crank axis by the motor such that at least one of the counterweight and the crank pin rotates through the slot.

[0005] In some examples, the counterweight may include a first distance and the crank pin may include a second distance greater than the first distance, wherein both the first distance and the second distance are measured in a direction perpendicular to the crank axis.

[0006] In some examples, the spindle may have a second end opposite the first end, and may be defined at a third distance between the first and second ends of the spindle. The spindle may include an anvil seat portion between the first and second ends, and may be defined at a fourth distance between the anvil seat portion and the first end of the spindle.

[0007] In some examples, the ratio of the fourth distance to the third distance can be between 1:1.5 and 1:2.

[0008] In some examples, the power tool may further include a fifth distance between the crank axis and the second end of the spindle, wherein the ratio of the fourth distance to the fifth distance may be between 1:1.5 and 1:2.5.

[0009] In some examples, the power tool may further include an anvil received in the spindle, the anvil defining a drill bit seat configured to receive a tool drill bit. When the anvil contacts the anvil seat, a sixth distance may be defined between the drill bit seat and the crank axis.

[0010] In some examples, the sixth distance can be between 130 mm and 160 mm.

[0011] In some examples, the average impact energy applied to the anvil can be between approximately 7.5 joules and 9 joules.

[0012] In some examples, the ratio of the sixth distance to the total length of the power tool, measured in a direction perpendicular to the crank axis, can be between 1:2 and 1:2.5.

[0013] In some examples, the ratio of the third distance to the sixth distance can be between 3:2 and 5:4.

[0014] In some examples, the ratio of the sixth distance to the fourth distance can be between 9:1 and 6:1.

[0015] In some examples, the power tool may further include a fifth distance between the crank axis and the second end of the spindle, wherein the ratio of the sixth distance to the fifth distance may be between 1:1.5 and 1:1.75.

[0016] In some examples, the motor may define a motor axis, and the spindle may define a spindle axis, wherein the ratio of a seventh distance between the motor axis and the spindle axis to the inner diameter of the spindle may be between 1:2 and 3:5.

[0017] According to another aspect of this disclosure, a power tool may include: a spindle defining an anvil seat portion between a first end and a second end; an anvil defining a drill bit seat portion configured to receive a tool drill bit, and the anvil engaging with the anvil seat portion to define a characteristic length of less than about 175 mm between the drill bit seat portion and the first end of the spindle; and a crankshaft that is rotated about a crank axis by a motor to apply an impact at the anvil with an average impact energy between about 7.5 joules and about 9 joules.

[0018] In some examples, the first end of the spindle may define a slot, and the crankshaft may include a counterweight that rotates through the slot.

[0019] In some examples, the length of the spindle chamber defined between the anvil seat and the first end of the spindle can be between about 100 mm and about 125 mm.

[0020] In some examples, the distance from the crank axis to the first end of the spindle can be between approximately 200 mm and approximately 250 mm.

[0021] In some examples, the maximum radius of the counterweight can be between approximately 20 mm and approximately 25 mm.

[0022] In some examples, the inner diameter of the spindle can be between approximately 25 mm and approximately 35 mm.

[0023] According to another aspect of this disclosure, a power tool may include: a motor; a spindle defining a first end having a slot and an anvil seat spaced apart from the first end; an anvil defining a drill bit seat configured to receive a tool drill bit, and the anvil engaging with the anvil seat to define a characteristic length of less than about 175 mm between the drill bit seat and the first end of the spindle; and a crankshaft including a counterweight and a crank pin, the counterweight and crank pin being rotatable about a crank axis by the motor such that at least one of the counterweight and the crank pin rotates through the slot.

[0024] The summary and abstract of this invention are provided to introduce, in a simplified form, some concepts that will be further described below in the detailed description. The summary and abstract are not intended to identify key or essential features of the claimed subject matter, nor are they intended to help determine the scope of the claimed subject matter. Attached Figure Description

[0025] The following figures are provided to illustrate various features of the non-limiting examples of this disclosure and are not intended to limit the scope of this disclosure or exclude alternative implementations.

[0026] Figure 1 An isometric view of a power tool according to aspects of this disclosure.

[0027] Figure 2 for Figure 1 The output component of the power tool, along Figure 1 A partial sectional view obtained from line 2-2.

[0028] Figure 3 for Figure 1 The output component of the power tool, along Figure 1 The partial sectional view obtained from line 3-3.

[0029] Figure 4 To surround Figure 2 A detailed view of the area obtained by line 4-4, which shows Figure 1 Details of the impact mechanism of the output component of the power tool.

[0030] Figure 5 for Figure 1 The output component of the power tool, along Figure 1 The partial sectional view obtained from line 5-5.

[0031] Figure 6 for Figure 1 Exploded isometric view of the retaining component of the output assembly of the power tool.

[0032] Figure 7 for Figure 1 The output component of the power tool drives the reciprocating drive component along the path. Figure 1 The enlarged sectional view obtained from line 7-7 shows details of the drive piston in the retracted position.

[0033] Figure 8 for Figure 7 A cross-sectional view of the drive piston in its extended position.

[0034] Figure 9 for Figure 1 An isometric view of the transmission device of the output component of a power tool.

[0035] Figure 10 To surround Figure 3 The detailed view obtained by line 10-10 shows the details of the drive piston in its fully extended position.

[0036] Figure 11 for Figure 10 A cross-sectional view of the drive piston in the first intermediate position between the fully extended position and the fully retracted position.

[0037] Figure 12 for Figure 10 A cross-sectional view of the drive piston in the second intermediate position between the fully extended position and the fully retracted position.

[0038] Figure 13 for Figure 10 A cross-sectional view of the drive piston in its fully retracted position.

[0039] Figure 14 for Figure 10 A cross-sectional view of the drive piston in the third intermediate position between the fully extended position and the fully retracted position.

[0040] Figure 15 To surround Figure 7The detailed view obtained from line 15-15 shows... Figure 1 Details of the transmission and motor of the power tool. Detailed Implementation

[0041] The following discussion is presented to enable those skilled in the art to make and use embodiments of the disclosed technology. Various modifications to the illustrated embodiments will be apparent to those skilled in the art upon benefit of this disclosure, and the principles herein can be applied to other embodiments and applications without departing from the embodiments of the disclosed technology. Therefore, the embodiments of the disclosed technology are not intended to be limited to those shown, but are accorded the widest scope consistent with the principles and features disclosed herein.

[0042] Please refer to the accompanying drawings for the following detailed description, in which similar elements in the different drawings have similar reference numerals. The drawings, not necessarily drawn to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the disclosed technology. Those skilled in the art will recognize that the examples provided herein have many useful alternatives and fall within the scope of embodiments of the disclosed technology.

[0043] Before explaining any embodiments of the invention in detail, it should be understood that the invention, in its application, is not limited to the details of the construction and arrangement of the components set forth in the following description or illustrated in the accompanying drawings. The invention can have other embodiments and can be practiced or performed in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting. The use of “comprising,” “including,” or “having,” and variations thereof herein is intended to cover the items listed thereafter and their equivalents and additional items. Unless otherwise specified or limited, the terms “installation,” “connection,” “support,” and “linkage,” and variations thereof, are used extensively and cover direct and indirect installation, connection, support, and linkage. Furthermore, “connection” and “linkage” are not limited to physical or mechanical connections or linkages.

[0044] Examples of the disclosed technology can be implemented on any kind of power tool that operates using a removable drill bit. In particular, some examples can be used with impact drives, including hammers, rotary hammers, or other known implementations. In this regard, for example, Figures 1-3 The example illustrates a power tool 100 in the form of a hammer-like tool (e.g., a chisel hammer); however, the concepts described herein can also be applied to other types of power tools. The power tool 100 includes a housing 104 and an electric motor 108 disposed within the housing 104. The power tool 100 may further include a reciprocating drive assembly 113 (in... Figure 2As shown in the diagram, the reciprocating drive assembly is coupled to motor 108 to convert torque from motor 108 (e.g., when motor 108 rotates about motor axis 120) into reciprocating motion. In some examples, reciprocating drive assembly 113 may be coupled to motor 108 via transmission 112. Impact mechanism 114 may be coupled to reciprocating drive assembly 113 to apply repeated axial impacts to tool bit 115 (e.g., chisel bit or output tool). Figure 1 As shown, the tool drill bit 115 can be slidably supported by a tool holder 130 coupled to the housing 104, allowing the tool drill bit 115 to translate along its axis to apply axial impact to the workpiece. In the illustrated example, the power tool 100 includes a quick-connect mechanism 138 coupled to the tool holder 130 for quick removal and replacement of different tool drill bits 115. In other applications, other types of chucks can be used instead of the quick-connect mechanism 138, which allows for drill bit changes with or without tools.

[0045] In some cases, housing 104 includes different parts that support different portions of the power tool 100. For example, housing 104 may include a pair of clamshell halves that provide an outer cover for the power tool 100. In some cases, housing 104 may include gearbox 200 that houses one or more of a transmission 112, a reciprocating drive assembly 113, or an impact mechanism 114. In the illustrated example, gearbox 200 includes an upper gearbox cover 204, a central gearbox cover 206, a lower gearbox cover 208, and a gearbox cap 212.

[0046] Continuing with the example illustrated for power tool 100, motor 108 can be configured as a direct current (DC) motor 108 that receives power from an installed power source (e.g., battery pack 118). Housing 104 may define a battery receiver 117 that removably receives battery pack 118. Battery pack 118 may contain any of a variety of different nominal voltages (e.g., 12V, 18V, etc.) and may be configured to have lithium-based chemistry (e.g., lithium, lithium-ion, etc.) or any other suitable chemistry. Alternatively, motor 108 may be powered by a remote power source (e.g., a household power outlet) via a power cord, or motor 108 may be a different type of motor, such as an alternating current (AC) motor. Motor 108 is selectively actuated by a push-button trigger, which in some cases may activate an internal switch. The switch may be electrically connected to motor 108 via a top-level controller or master controller 198 (e.g., a microcontroller) or one or more circuits for controlling the operation of motor 108.

[0047] For details, please refer to the following: Figure 2 and Figure 3 The gearbox 200 includes a spindle housing 214 that supports the spindle 160 (e.g., a cylindrical component). The spindle housing 214 is covered by a protective cover 216. In some cases, the protective cover 216 may be formed of a thermally insulating material (e.g., rubber, fiberglass, mineral wool, cellulose, polyurethane, polystyrene, etc.). In some cases, the protective cover 216 may include a gripping area 220 that can be gripped by a user (e.g., while operating the power tool 100). For example, during operation of the power tool 100, friction, vibration, expansion and contraction of cavitation within the spindle 160, operation of the motor 108, or other factors may generate heat that could raise the temperature of the gearbox 200. Therefore, the protective cover 216 can provide a protective layer to isolate the user's hand from the gearbox 200. In some cases, the protective cover 216 may include a relatively high coefficient of friction in the gripping area 220 and prevent the power tool 100 from slipping from the user's hand during operation.

[0048] Furthermore, the gripping area 220 includes heat dissipation elements. For example, the spindle housing 214 may include a wall 224 and a plurality of ribs 228 extending from the wall 224. In this case, the wall 224 and ribs 228 are configured as a cylindrical wall and circumferential ribs, respectively; however, other wall and rib configurations are also possible. The ribs 228 may project outward from the wall 224 toward the protective cover 216 and are spaced apart from each other in a direction parallel to the reciprocating axis 168 (e.g., the impact axis). Figure 2 and Figure 3 As shown, in the gripping area 220 of the protective cover 216, the rib 228 contacts the protective cover 216 and minimizes the contact area between the protective cover 216 and the gearbox 200. Therefore, the reduced heat can be transferred directly from the gearbox 200 to the protective cover 216, and the user's hand is isolated when positioned on the gripping area 220.

[0049] Continue to refer to Figure 2 and Figure 3A reciprocating drive assembly can be configured to convert the rotational motion of a motor (e.g., via a transmission) into the reciprocating linear motion of a piston. In the illustrated example, the reciprocating drive assembly 113 includes a crankshaft 132, a reciprocating piston 156, and a connecting rod 144. The connecting rod 144 is connected to the crankshaft 132 at a first end 148, and a second end 152 is opposite the first end 148. In some cases, the connecting rod 144 may be pivotally coupled to the crankshaft 132 at each of the first end 148 and the second end 152. The crankshaft 132 is configured to receive torque from the motor 108 and rotate about a crank axis 136 (e.g., the crankshaft axis). In the illustrated example, the crankshaft 132 includes a crank pin 140 coupled to the first end 148 of the connecting rod 144, which may be coupled to the piston 156 at the second end 152. Correspondingly, when the crankshaft 132 rotates about the crank axis 136, the connecting rod 144 drives the piston 156 to reciprocate along the reciprocating axis 168 within the main shaft 160 supported in the housing 104. Figure 3 As shown, the connecting rod 144 includes a length L8 (e.g., the connecting rod length), which is measured between the axis corresponding to the connection with the crank pin 140 and the axis corresponding to the connection with the piston 156. In some cases, the length L8 may be between 35 mm and 65 mm, or between 40 mm and 50 mm, or approximately 45 mm. In the illustrated example, the spindle 160 is fixed. However, in other examples, such as a rotary hammer, the spindle 160 may be rotated by a motor 108 to cause the tool drill bit to rotate.

[0050] In some embodiments, the reciprocating drive assembly 113 may be implemented by other mechanisms, including those known in the art that convert rotary motion into reciprocating motion (e.g., scotch-yoke mechanisms, oscillating drive mechanisms, swashplate mechanisms, etc.). In this regard, although the various tool holders discussed below can be used in conjunction with the reciprocating drive assembly 113 illustrated in the examples, various other implementations are also possible.

[0051] A reciprocating assembly moves to generate an impact on the tool drill bit via an impact mechanism. That is, the impact mechanism moves in response to the movement of the reciprocating assembly to generate an impact on the tool drill bit. In the illustrated example, the impact mechanism 114 includes an impactor 164 and an anvil 172 movably received in a spindle 160. The impactor 164 is positioned between a piston 156 and an anvil 172 and selectively reciprocates within the spindle 160 in response to the reciprocating motion of the piston 156. As the impactor 164 reciprocates toward the tool drill bit 115, the anvil 172 engaging the tool drill bit 115 is impacted by the impactor 164. The impact between the impactor 164 and the anvil 172 can be transmitted to the tool drill bit 115, causing the anvil 172 to reciprocate together with the tool drill bit 115, thereby performing work on the workpiece (e.g., impacting the workpiece). In the illustrated example, the anvil 172 includes an inner bore 174 for receiving the shank 177 of the drill bit 115. Further, in the illustrated configuration of the power tool 100, the spindle 160 is hollow and defines an internal chamber 162 (e.g., a bore) in which an impactor 164 is received. As the piston 156 reciprocates within the spindle 160, an air spring 190 (e.g., a cavitation or air cushion) can be formed between the piston 156 and the impactor 164, whereby the expansion and contraction of the air spring 190 causes the reciprocating motion of the impactor 164. That is, as the piston 156 moves toward the impactor 164, the volume of the air spring 190 decreases, which increases the pressure within the air spring 190. This increase in pressure may be sufficient to cause the impactor 164 to move in the same direction as the piston 156 and to impact the anvil 172 to transmit the impact to the workpiece via the drill bit 115. Conversely, as the piston 156 moves away from the impactor 164, the volume of the air spring 190 can increase, which reduces the pressure within the air spring 190. This reduction in pressure is sufficient to cause the impactor 164 to move in the same direction as the piston 156, thereby causing the impactor 164 to retract and move away from the anvil 172.

[0052] In some cases, the impactor 164 or anvil 172 may form a seal against the inner surface of the spindle 160 via one or more sealing rings (e.g., O-rings 166). In some examples, maintaining the seal between the impactor 164 and the spindle 160 may help retain the air spring 190 formed within the internal chamber 162.

[0053] In some non-limiting cases, the motor 108 may be positioned within the housing 104 (e.g., within a gearbox disposed within the housing 104), and the spindle 160 may be coupled to the housing 104. In some non-limiting cases, the motor 108 may be positioned within the housing 104, and the spindle 160 may be rotatable. For example, a transmission 112 between the motor 108 and the spindle 160 may transmit torque from the motor 108 to the spindle 160, thereby causing the spindle 160 to rotate when the motor 108 is started. The transmission 112 may include a gear train, but other types of transmission systems may also be used, such as belt drives, chain drives, etc.

[0054] Continuing, the power tool 100 includes a retaining feature that guides axial movement of the anvil 172 along the reciprocating axis 168. For example, as Figure 4 As shown, a retainer 176 is disposed at the distal end of the spindle 160. The retainer 176 defines a hole 180 (e.g., a cylindrical hole) for receiving a tool drill bit 115. In the illustrated example, the retainer 176 is coupled to the spindle 160 via a fastener (e.g., a fastener or retaining member). The retainer 176 defines a retainer impact surface 188 that can engage with a corresponding surface of the anvil 172. In the illustrated example, the anvil 172 defines a front anvil impact surface 184 that generally faces the front of the power tool 100 (e.g., towards a tool holder). As the anvil 172 moves along the reciprocating axis 168 toward the front of the power tool 100, the retainer impact surface 188 can engage with the front anvil impact surface 184 and prevent further movement of the anvil 172 toward the front of the power tool 100. In the illustrated example, the profile of the anvil impact surface 184 generally corresponds to the profile of the retainer impact surface 188. For example, each of the impact surfaces 184 and 188 may be a truncated conical shape. In other embodiments, the profiles of the anvil impact surface 184 and the retainer impact surface 188 may be different or include different shapes (e.g., pyramidal, cylindrical, spherical, cubic, cuboid, conical, etc.).

[0055] Furthermore, the anvil 172 is configured to engage with the spindle 160 during the reciprocating motion of the power tool 100. For example, as Figure 4As shown, the anvil 172 defines a rear anvil impact surface 268 located at the rear end of the anvil 172, which is generally opposite to the front anvil impact surface 184. The rear anvil impact surface 268 includes a first rear surface 269 that can engage (directly) with the impact member 164 during reciprocating motion and a second rear surface 270 that can engage with the spindle 160. In some cases, the rear anvil impact surface 268 may be arranged to generally face the rear of the power tool 100 (e.g., towards the impact member 164). In the illustrated example, the second rear surface 270 is generally conical, and the first rear surface 269 protrudes from the second rear surface 270 toward the impact member 164. Further, the second rear surface 270 engages with a corresponding surface of the spindle 160. In particular, the spindle 160 may include ribs 272 that project from the spindle wall 232 of the spindle 160 and extend circumferentially along the inner surface of the spindle wall 232. Rib 272 may define a spindle impact surface 276 arranged toward the second rear surface 270 of the rear anvil impact surface 268. Therefore, as the anvil 172 moves toward the rear of the power tool 100 along the reciprocating axis 168, the spindle impact surface 276 may engage with the second rear surface 270 and prevent further movement of the anvil 172 toward the rear of the power tool 100. In some cases, the profile of the spindle impact surface 276 may substantially correspond to the profile of the second rear surface 270. For example, each of the impact surfaces 270 and 276 may be a truncated conical shape. In other embodiments, the profiles of the rear anvil impact surface 268 and the spindle impact surface 276 may differ or include different shapes (e.g., pyramidal, cylindrical, spherical, cubic, cuboid, conical, etc.).

[0056] In some configurations, when the anvil 172 directly or indirectly contacts the retainer 176 or the spindle 160, the retainer 176 or the spindle 160 can absorb the impact force applied to the anvil 172 by the impactor 164 along the reciprocating axis 168. For example, repeated impacts of the impactor 164 on the anvil 172 can cause the anvil 172 to reciprocate between the retainer 176 and the spindle 160. When the anvil 172 impacts the retainer 176, the impact force can be absorbed by the spindle 160, which is connected to the anvil 172 via the retainer 192.

[0057] In these cases, the retainer 176 and spindle 160 can provide shock-absorbing features that absorb at least a portion of the impact force exerted by the impactor 164 or at least a portion of the reaction force exerted by the workpiece during operation. For example, when the anvil 172 moves rearward toward the spindle 160, the rear anvil impact surface 268 can contact the spindle impact surface 276. The impact force can be transmitted to the spindle 160, thereby dispersing the force through the spindle 160. When the anvil 172 moves forward toward the retainer 176, the front anvil impact surface 184 can contact the retainer impact surface 188. The impact force exerted by the impactor 164 can be transmitted to the anvil 172, and the transmitted impact force can then be transmitted to the retainer 176 and spindle 160 via the retainer 192. Correspondingly, the impact force exerted by the impactor 164 can be dispersed by directing the force to the spindle 160 or other components of the power tool 100.

[0058] In conventional power tool designs, impacts can occur even when the tool bit is not in contact with the workpiece, resulting in dry-firing. To prevent impacts when the power tool is not in contact with the workpiece (thus reducing operator fatigue and tool wear), conventional designs for impact tools provide parking features that prevent the impactor from reciprocating within the spindle. For example, O-rings are included to restrict anvil movement and prevent contact between the impactor and the anvil. However, such parking features increase the complexity of the manufacturing process and the overall size of the tool. According to aspects of this disclosure, providing a retainer for the anvil and a protruding wall in the spindle can reduce or eliminate the need for parking features (e.g., for preventing dry-firing), which typically increase the length of the power tool. For example, by arranging the anvil between a retainer (e.g., retainer 176) and a protruding wall (e.g., rib 272), the travel length of the anvil between the retainer and the protruding wall can be limited or reduced, and the efficiency of the power tool can be improved.

[0059] Specifically, continue to refer to Figure 4 Distance traveled D T It can be defined as the distance D between the stopped surfaces. S Distance D from the impact surface of the anvil A The difference between them (i.e., D) T =D S –D A Each of the corresponding distances is obtained along the same line extending in the axial direction (e.g., approximately parallel to axis 168). For example, the stop surface distance D S The measurement is taken between the impact surface 188 of the retainer and the impact surface 276 of the spindle, and the distance D between the anvil impact surface and the anvil impact surface is...A It is measured between the front anvil impact surface 184 and the rear anvil impact surface 268. In some cases, the travel distance D T The distance that the anvil 172 can travel along the reciprocating axis 168 between the retainer 176 and the spindle 160 can be either a distance limited by other components of the power tool 100. In the illustrated embodiment, the stop surface distance D... S The distance D between the impact surfaces of the anvil can be compared. A A small distance. Correspondingly, the travel distance D of the anvil 172. T It can be less than the distance D from the stop surface. S For example, in some embodiments, the travel distance D T It can be less than or equal to the distance D between the stopping surfaces. S 50% of the distance traveled. In other embodiments, the distance traveled D... T It can be less than or equal to the distance D between the stopping surfaces. S 25%. In the illustrated embodiment, the travel distance D T It can be less than or equal to the distance D between the stopping surfaces. S 20%. In a further embodiment, the travel distance D T It can be less than or equal to the distance D between the stopping surfaces. S 10%. By dispersing the impact force generated during the operation of the power tool 100 into the retainer 176, retainer 192, and spindle 160, the need for dwell features can be reduced or eliminated, and the travel distance D T The distance D relative to the stop surface S This reduction advantageously allows for a reduction in the overall length of the power tool 100 compared to conventional chisels and hammers.

[0060] Figure 5 and Figure 6 The example illustrates the details of the retainer 176 and surrounding features. Specifically, the spindle 160 may include a spindle wall 232 defining a bore 236 within which the piston 156, impactor 164, and anvil 172 reciprocate. The spindle 160 includes a proximal end 240 near the motor 108 and crank axis 136 (about which the gear 128 rotates) (e.g., as shown in the image). Figure 2 and Figure 3 (as shown in the diagram); and the distal end 244, which is away from the motor 108 and toward the front of the power tool 100. The retainer 176 may include a retainer wall 248. A portion of the retainer wall 248 may be received in the bore 236 at the distal end 244 of the spindle 160 and fit tightly with the spindle wall 232 (e.g., nominal sliding fit).

[0061] The retainer 176 may include features and elements for coupling with the spindle 160. For example, the retainer wall 248 may define a plurality of recesses 252, which are circumferentially spaced apart from each other and axially aligned relative to the reciprocating axis 168. In some cases, the size and shape of the recesses 252 may be designed to receive the retaining member 192. In the illustrated embodiment, the retaining member 192 is cylindrical, and the recesses 252 are correspondingly shaped as cylinders to receive corresponding portions of the retaining member 192. In other embodiments, the retaining member 192 may alternatively include different shapes (e.g., oval, spherical, truncated conical, prismatic, arcuate, etc.), and the recesses 252 may be correspondingly shaped to (closely) receive the retaining member.

[0062] Similarly, the spindle 160 may include features and elements for engagement with the retainer 176. For example, the spindle wall 232 may define a plurality of apertures 256 extending therethrough, allowing access to the bore 236 via the plurality of apertures 256. The apertures 256 may be circumferentially spaced apart from each other and axially aligned relative to the reciprocating axis 168. The size and shape of the apertures 256 may be designed to receive corresponding portions of the retainer 192. In the illustrated embodiment, the retainer 192 is shaped as a cylinder, and the apertures 256 are correspondingly shaped as cylinders to tightly receive corresponding portions of the retainer 192. In other embodiments, the apertures 256 may include different shapes to (tightly) receive corresponding shaped retainers (which may not be shaped as cylinders).

[0063] Continue to refer to Figure 5 and Figure 6 The recess 252 of the retainer 176 can be aligned with the orifice 256 of the spindle 160. The retainer 192 can be disposed through the recess 252 and the orifice 256. Specifically, a first portion of each retainer 192 can be disposed in a corresponding recess 252, and a second portion (e.g., the remaining portion) of each retainer 192 can be disposed in a corresponding aligned orifice 256. Thus, the retainer 192 can provide a coupling mechanism to connect the retainer 176 to the spindle 160.

[0064] In some cases, the gearbox cap 212 may be disposed at the distal end 244 of the spindle 160, and the retaining member 192 may be held within the recess 252 and the orifice 256. The gearbox cap 212 may include a flange 260 and a cap wall 264 extending axially away from the flange 260. In some cases, the cap wall 264 may be cylindrical, but other shapes are also possible. The cap wall 264 is fitted onto the distal end 244 adjacent to the retaining member 192, and the retaining member 192 is held in place within the recess 252 and the orifice 256. In some cases, the flange 260 may be secured to the gearbox 200 (e.g., via fasteners such as screws or adhesive).

[0065] In some cases, the retaining member 192 may be formed of a first material having a first Young's modulus. The spindle 160 may be formed of a second material having a second Young's modulus. The retaining member 176 may be formed of a third material having a third Young's modulus. In some cases, the first, second, and third materials may each comprise a hard and rigid material (e.g., metal, hardened steel, etc.). In other embodiments, different types of materials with different rigidities may be provided, including elastomers, rubber, wood, plastics, concrete, glass, highly permeable materials, low-permeability materials, ferrous materials, etc. In some embodiments, the first Young's modulus may be equal to or greater than the second Young's modulus, and equal to or greater than the third Young's modulus. In some cases, two or more of the first, second, and third materials may be the same or different.

[0066] Furthermore, in the illustrated embodiment, the power tool 100 includes eight retaining members 192 and eight corresponding recesses 252 and orifices 256, the retaining members, recesses, and orifices being circumferentially spaced at equal intervals around the main axis 160. In other embodiments, the power tool 100 may include fewer retaining members, corresponding recesses, and corresponding orifices (e.g., one, two, three, four, five, six, or seven). In some embodiments, the power tool 100 may include more retaining members, corresponding recesses, and corresponding orifices (e.g., more than eight).

[0067] Figures 7-9The motor 108, transmission 112, and reciprocating drive assembly 113 are illustrated in more detail. Specifically, the crankshaft 132 includes a counterweight 280 and a crank 284 including a crank pin 140. The counterweight 280 may be defined by a distance L1 (e.g., a radial distance, a first distance), measured along the reciprocating axis 168 between the crank axis 136 and a first distal edge of the counterweight 280. The crank 284 may be further defined by a distance L2 (e.g., a radial distance, a second distance), measured along the reciprocating axis 168 between the crank axis 136 and a second distal edge of the counterweight 280 on the side containing the crank 284. In the illustrated example, the distance L1 of the counterweight 280 is shorter than the distance L2 of the crank 284. In some cases, a shorter distance L1 can allow the counterweight 280 to be in the fully retracted position (e.g., at bottom dead center, such as...) when the drive piston 156 is in the fully retracted position. Figure 7 (As shown in the diagram) Avoid contact with the drive piston 156. In some cases, a larger distance L2 of crank 284 can increase the crank radius R1 of crank pin 140. In particular, as shown in the diagram... Figure 7 As shown, the crank radius R1 is the distance between the crank axis 136 and the axis of the crank pin 140. However, the illustrated example provides an arrangement of crank 284 such that crank 284 can be arranged closer to the transmission 112, or rotate away from the drive piston 156 at bottom dead center, without interfering with the drive piston 156, spindle 160, or other components of the transmission 112. In some cases, the crank radius R1 (e.g., as...) Figure 7 The distance L1 (as shown) can be between 10 mm and 25 mm, or between 15 mm and 20 mm, or approximately 17 mm. The distance L2 can be between 13 mm and 23 mm, or between 15 mm and 20 mm, or approximately 18 mm. The distance L2 can be between 15 mm and 30 mm, or between 20 mm and 25 mm, or approximately 23 mm. In some examples, the distance L2 can be configured as the maximum radius of the counterweight 280.

[0068] In particular, such as Figure 9 As best illustrated, the proximal end 240 of the spindle 160 may include a plurality of cutouts or slots 292 located on each respective lateral side of the spindle 160. In some cases, each slot 292 may be defined between the upper edge 296 and the lower edge 300 of the spindle 160. In the illustrated example, the spindle 160 is arranged below the gear 128, and when the drive piston 156 is in the fully extended position (e.g., at top dead center position, as shown in the example), the spindle 160 is positioned below the gear 128. Figures 8-10As shown in the illustration, crank 284 can at least partially overlap with the upper edge 296 and lower edge 300 in a direction parallel to the crank axis 136. In other words, at least a portion of crank 284 of crankshaft 132 can pass between the upper edge 296 and lower edge 300 of spindle 160 when drive piston 156 approaches or returns from the fully extended position. Thus, slot 292 can allow crank 284 to rotate about crank axis 136 and provide translational movement to drive piston 156 without interfering with spindle 160 (e.g., which remains stationary in the hammer) or drive piston 156. In the illustrated example, piston 156 can maintain skirt engagement with spindle 160 by contacting upper edge 296 and lower edge 300, and can prevent torsion within spindle 160 during operation. In some examples, maintaining the skirt engagement between the piston 156 and the spindle 160 can help extend tool life by reducing excessive lateral loads on the inner wall of the spindle 160 and keeping the piston aligned within the bore of the spindle 160.

[0069] In some cases, the exemplified configuration of spindle 160 can allow for a compact arrangement of the reciprocating drive assembly 113 or transmission 112 within gearbox 200 and a shortened overall length of power tool 100. For example, the slot 292 of spindle 160 or other types of slotted geometry can allow a distance L2 greater than distance L1 and achieve the desired performance level of power tool 100 (e.g., average impact energy from about 7.5 joules to about 9 joules). Furthermore, the slot 292 of spindle 160 or other types of slotted geometry can allow for a shorter geometry of connecting rod 144. In some examples, the configuration of reciprocating drive assembly 113 can provide a desired length L7 (e.g., impact position length, such as...) between crank axis 136 and rear surface 165 of impact member 164. Figure 2(As shown in the illustration). In some examples, the length L7 can be between 50 mm and 150 mm, or between 75 mm and 125 mm, or approximately 106 mm. In some examples, the ratio of length L7 to crank radius R1 can be less than 6.75, or less than 6.50, or less than 6.25. In the illustrated example, the ratio of length L7 to crank radius R1 is approximately 6.18. In some examples, the ratio of length L7 to length L8 of connecting rod 144 can be greater than 1.80, or greater than 1.90, or greater than 2.00. In the illustrated example, the ratio of length L7 to length L8 of connecting rod 144 is approximately 2.35. In some examples, the ratio of crank radius R1 to length L8 can be greater than 0.24, or greater than 0.30. In the illustrated example, the ratio of crank radius R1 to length L8 is 0.38. In some cases, a higher ratio of crank radius R1 to length L8 can be associated with a smaller angle (e.g., angle A1 or angle A2) between crank 284 and connecting rod 144. In a further example, the ratio of the impact energy of power tool 100 to length L8 can be greater than 0.13, or greater than 0.17, or greater than about 0.20.

[0070] Furthermore, while the illustrated embodiment of the reciprocating drive assembly 113 includes a crank mechanism, the reciprocating drive assembly 113 may include other types of mechanisms, including oscillating bearing mechanisms, Scottish yoke mechanisms, rack and pinion mechanisms, camshaft mechanisms, swashplate mechanisms, etc. For example, in a reciprocating drive assembly 113 including an oscillating bearing mechanism, the crank radius R1 (e.g., the throw distance) may be equal to the length of the piston throw of the oscillating bearing mechanism.

[0071] Figures 10-14 The example illustrates the operating views of the transmission 112 and the reciprocating drive assembly 113 at different locations. As generally described above, the spindle 160 may include features that allow the crank 284 to rotate without interference between the fully extended and fully retracted positions of the drive piston 156.

[0072] Figure 10 The example illustrates the drive piston 156 in its fully extended position (e.g., at top dead center). In the illustrated example, the connecting rod 144 is aligned along the reciprocating axis 168. A portion of the crank 284 and the crank pin 140 are at least partially disposed within the main shaft 160 at the proximal end 240. For example, the crank 284 and the crank pin 140 are at least partially aligned with the upper edge 296 (e.g., as shown in the image). Figures 7-9(as shown in the diagram) and overlap the lower edge 300. The counterweight 280 is arranged toward the rear end of the power tool 100 (e.g., toward the motor 108).

[0073] Figure 11 The example illustrates a fully extended position (e.g., as shown in the image). Figure 10 (as shown) and the fully retracted position (e.g., as shown) Figure 13 The drive piston 156 is located at a first intermediate position, partially retracted (e.g., partially extended), between the positions shown in the illustration. In the illustrated example, the crankshaft 132 rotates counterclockwise about the crank axis 136 from a fully extended position to a 45-degree position, and the connecting rod 144 is arranged at an angle relative to the reciprocating axis 168. In some cases, at least a portion of the connecting rod 144 may be arranged at the upper edge 296 (e.g., as shown in the illustration). Figures 7-9 The counterweight 280 is located in one of the slots 292 arranged between the main shaft 160 and the lower edge 300 (as shown in the diagram). At this location, the crank 284 and crank pin 140 are arranged outside the main shaft 160. The counterweight 280 can rotate 45 degrees about the crank axis 136.

[0074] Figure 12 The example illustrates a second intermediate position of the drive piston 156, which includes a drive piston 156 further translated toward the motor side of the power tool 100. In the illustrated example, the crankshaft 132 rotates counterclockwise about the crank axis 136 from a 45-degree position to a 90-degree position. The connecting rod 144 is arranged at an angle relative to the reciprocating axis 168. Specifically, the angle A1 between the connecting rod 144 and the crank 284 can be between 60° and 80°, or between 65° and 75°, or about 68°. In this position, at least a portion of the connecting rod 144 can be arranged in a slot 292. The crank 284 and crank pin 140 are arranged outside the main shaft 160, and a portion of the counterweight 280 is located at the upper edge 296 (e.g., as shown). Figures 7-9 The counterweight 280 is arranged within the main shaft 160 between the crankshaft 132 (shown in the diagram) and the lower edge 300. Specifically, when the crankshaft 132 rotates from a 45-degree position to a 90-degree position, the counterweight 280 can slide into the slot 292. Therefore, the crankshaft 132 can rotate without interfering with the main shaft 160 or the piston 156, and the piston 156 can continue to translate within the main shaft 160 along the reciprocating axis 168.

[0075] Figure 13The example illustrates the drive piston 156 in its fully retracted position. In the illustrated example, the crankshaft 132 rotates counterclockwise about the crank axis 136 from a 90-degree position to a 180-degree position. In this position, the drive piston 156 may be located at bottom dead center. A portion of the drive piston 156 may axially overlap with the slot 292 and be positioned between the upper edge 296 and the lower edge 300. In some cases, in this position, the upper edge 296 and the lower edge 300 may protrude beyond the drive piston 156, i.e., closer to the crank axis 136. Furthermore, the counterweight 280 may be located near the proximal end 240 of the main shaft 160 and disposed outside the main shaft 160. The connecting rod 144 may axially overlap the counterweight 280 above it and may extend along the reciprocating axis 168.

[0076] Figure 14 The example illustrates a third intermediate position of the drive piston 156, partially retracted, between its fully extended and fully retracted positions. In this illustrated example, the crankshaft 132 rotates counterclockwise about the crank axis 136 from a 180-degree position to a 270-degree position. The connecting rod 144 is arranged at an angle relative to the reciprocating axis 168. Specifically, the angle A2 between the connecting rod 144 and the crank 284 can be between 60° and 80°, or between 65° and 75°, or approximately 68°. In this position, a portion of the connecting rod 144 can be arranged in one slot of the slots 292, and a portion of the counterweight 280 can be arranged in another slot of the slots 292.

[0077] In some cases, the drive piston 156 can be drawn from, for example... Figure 14 The 270-degree position shown continues to extend to complete one stroke of the drive piston 156. In some cases, the crankshaft 132 can rotate clockwise (opposite to the direction described above). By allowing portions of the crankshaft 132 to slide through the slot 292 as it rotates about the crank axis 136, the drive piston 156 can continue its reciprocating motion without interference, while maintaining a compact arrangement of components within the power tool 100.

[0078] refer to Figure 15Examples of this disclosure may provide an arrangement of a transmission 112 that can reduce or eliminate displacement of the rotor of the motor 108 along the motor axis 120 during operation of the power tool 100. For example, the transmission 112 includes a central gearbox cover 206 arranged adjacent to the motor 108 and defining a bearing recess 310. In some cases, a bearing 314 including an outer race 316 may be arranged within the bearing recess 310. A bearing retainer 312 may be secured to the central gearbox cover 206 (e.g., via fasteners such as screws) and may abut the outer race 316 to secure it within the bearing recess 310. When the pinion 124 rotates relative to the outer race 316 and the central gearbox cover 206, the inner race 318 of the bearing 314 may engage with the pinion 124. In some cases, the pinion 124 may be connected to one end of the motor shaft 116 and includes a flange 322 abutting the axial end face of the inner race 318. A retaining member 320 (e.g., a snap ring, E-clamp, etc.) can be provided within the groove 126 formed in the pinion 124. The retaining member 320 can engage with the opposing axial end faces of the inner race 318. Therefore, by placing the bearing 314 between the head portion of the pinion 124 and the retaining member 320, the translational movement of the pinion 124 can be restricted. In some cases, the axial position of the inner race 318 can be determined by the axial position of the outer race 316. In some cases, the axial position of the outer race 316 can be determined by the central gearbox cover 206 and the bearing retaining member 312. Therefore, the arrangement of the central gearbox cover 206 can determine the axial position of the pinion 124.

[0079] Furthermore, the motor 108 may include a stator assembly 330 and a rotor assembly 332, the rotor assembly being rotatably supported on the motor shaft 116 relative to the stator assembly 330. The rotor assembly 332 may include a rotor core 334 (e.g., lamination stack) disposed on the motor shaft 116 (e.g., via press fit or nominal interference fit). The rotor core 334 may define a first axial end surface 336 that contacts a corresponding second axial end surface 338 defined on the pinion 124. Thus, the pinion 124 secures the rotor core 334 to prevent it from translating in the forward direction (i.e., toward the central gearbox cover 206).

[0080] During operation of the power tool 100, the rotor core 334 may have a tendency to slide on the motor shaft 116. In some cases, due to reciprocating and impact forces acting on one or more of the drive piston 156, impactor 164, anvil 172, or tool bit 115, the rotor core 334 may translate axially toward the central gearbox cover 206. In some cases, the contact between the pinion 124 and the rotor core 334 can prevent the rotor core 334 from sliding and translating toward the central gearbox cover 206 during operation of the power tool 100.

[0081] Back Figure 2 One or more components of the power tool 100 may include various dimensions characterizing the dimensional relationships between the relative positions of the different components of the power tool 100. In some cases, characterizing various dimensional relationships may be useful for changing the overall size of the power tool 100 (e.g., to provide a compact power tool in the vertical or horizontal direction). For example, the power tool 100 may include a distance D1 (e.g., a characteristic length, a sixth distance) measured between a crank axis 136 and a first longitudinal axis 350 extending through the seat 175 of the receiving tool drill 115 of the anvil 172. The distance D1 is measured in a direction parallel to the reciprocating axis 168. Because the anvil 172 is movable within the spindle 160, the distance D1 is measured when the anvil 172 is fully retracted to contact a rib 272 (e.g., the anvil seat) defined in the spindle 160 to limit the movement of the anvil 172 toward the impact member 164 (e.g., toward the crankshaft 132). In some cases, the fully retracted position of the anvil 172 can be associated with the working or impact position of the power tool 100. Therefore, when the tool bit 115 is inserted, the distance D1 corresponds to the shortest overall length of the power tool 100.

[0082] In some cases, the distance D1 may be between 100 mm and 200 mm, or between 120 mm and 180 mm, or between 130 mm and 160 mm, or approximately 142 mm. In some cases, the distance D1 may be less than 200 mm, less than 175 mm, or less than 156 mm. In some cases, the ratio of the distance D1 to the total length L4 of the power tool 100 (e.g., the length without the tool bit installed or the length of the rear housing of the complete assembly) may be between 3:10 and 3:5, or between 2:5 and 1:2, or approximately 9:20. In particular, the total length L4 may be measured between the second longitudinal axis 352 extending through the distal end 178 of the retainer 176 and the third longitudinal axis 354 extending through one end of the motor 108, and in a direction parallel to the reciprocating axis 168. In some cases, the total length L4 can be between 200 mm and 400 mm, or between 250 mm and 350 mm, or between 275 mm and 325 mm, or approximately 297 mm.

[0083] In some cases, the distance D1 can be varied to adjust the length L4 of the power tool 100 measured in the direction parallel to the reciprocating axis 168. For example, decreasing the distance D1 can shorten the overall length of the power tool 100, while increasing the distance D1 can lengthen the overall length of the power tool 100. In some examples, various dimensions of the spindle 160 can be adjusted to change the distance D1. For example, the internal cavity 162 of the spindle 160 contains a length L3 (e.g., a fourth distance) measured in the direction parallel to the reciprocating axis 168, and the spindle 160 may contain an inner diameter ID measured in the direction parallel to the crank axis 136. For example, the inner diameter ID may be between 15 mm and 40 mm, or between 25 mm and 35 mm, or about 32.5 mm. Further, the length L3 may be between 75 mm and 150 mm, or between 100 mm and 125 mm, or about 112 mm. In some cases, the length L3 can be decreased to shorten the distance D1, or the length L3 can be increased to lengthen the distance D1. In some examples, the distance D1 is greater than 100%, 120%, or 150% of the length L3, etc. In some cases, the inner diameter ID can be increased or decreased accordingly to keep the volume of the internal chamber 162 constant (e.g., to maintain the desired impact energy via the air spring 190). In some examples, the inner diameter ID can be changed to obtain the desired amount of impact energy without lengthening or shortening the entire length L4. In some cases, the inner diameter ID can be significantly increased to receive an impactor 164 with a larger volume or greater mass, for example, to achieve greater impact energy for the power tool 100. In some cases, the mass of the impactor 164 can be between 70 grams and 160 grams, or between 100 grams and 130 grams, or approximately 123 grams.

[0084] Furthermore, in some examples, the slot 292 of the spindle 160 may contain a length L5 measured in a direction parallel to the reciprocating axis 168. The length L5 can be adjusted to change the length L3 or the distance D1. For example, the length L5 may be between 5 mm and 10 mm, or approximately 8 mm. In some cases, the length D1 can be changed by adjusting the distance D3, measured in a direction parallel to the reciprocating axis 168, between one end of the spindle 160 and the crank axis 136. For example, the distance D3 may be between 15 mm and 25 mm, or between 17 mm and 23 mm, or approximately 21 mm. In some cases, the ratio of distance D1 to distance D3 may be between 10:1 and 5:1, or between 9:1 and 6:1, or approximately 27:4.

[0085] In some cases, the distance D1 can be determined based on the desired impact energy of the power tool 100. For example, a distance D1 of approximately 142 mm can be associated with an impact energy of the power tool 100 between 5 joules (J) and 10 J, or between 8 J and 9 J. In some cases, the distance D1 can be characterized as being between approximately 10 mm per J and approximately 20 mm per J, or between 15.8 mm per J and 17.6 mm per J. In some cases, the power tool 100, including the desired length L3, can generate an average impact energy of approximately 8 J to approximately 9 J per stroke. In some cases, the power tool 100 can maintain a predetermined amount of desired impact energy regardless of how the distance D1 varies. For example, one or more of the rated power of the motor 108, the drive mode of the power tool 100, or the operating speed of the motor 108 can be determined based on the distance D1. In some cases, the power tool 100 may define the ratio of the impact energy of the power tool 100 to its bare weight (e.g., the weight of the power tool 100 without the drill bit and battery pack 118) to a ratio greater than 0.50 J / kg, or greater than 0.75 J / kg, or greater than 1.00 J / kg, or about 1.25 J / kg.

[0086] Furthermore, the power tool 100 may be defined by a distance D2 (e.g., a fifth distance) between the crank axis 136 and the second longitudinal axis 352. Distance D2 is measured in a direction parallel to the reciprocating axis 168. In some cases, distance D2 may be between 200 mm and 250 mm, or between 210 mm and 240 mm, or between 220 mm and 230 mm, or approximately 224 mm. In some cases, distance D2 may be at least 100% of distance D1, or at least 125% of distance D1, or at least 150% of distance D1, or approximately 160% of distance D1. In other words, the ratio of distance D1 to distance D2 may be between 1:1.3 and 1:2, or between 1:1.5 and 1:1.75, or approximately 1:1.6. In some cases, the ratio of distance D2 to the total length L4 of the power tool 100 can be between 1:2 and 1:1, or between 3:5 and 9:10, or between 7:10 and 4:5, or approximately 3:4. In some examples, the ratio of length L3 to distance D2 can be between 1:4 and 1:1, between 1:3.5 and 1:2.5, or approximately 1:2.

[0087] In some cases, distance D2 can be changed to adjust the overall length of the power tool 100 measured in the direction parallel to the reciprocating axis 168. In some examples, the dimensions of different components of the power tool 100 (e.g., spindle 160, tool holder 130, retainer 176, spindle housing 214, etc.) can be adjusted to reduce distance D1 or distance D2. For example, spindle 160 may include a length L6 (e.g., a third distance) measured in the direction parallel to the reciprocating axis 168. In some cases, length L6 may be between 150 mm and 250 mm, or between 175 mm and 225 mm, or approximately 201 mm. In some cases, the ratio of length L3 to length L6 may be less than 1:1, less than 1:1.5, less than 1:2, less than 1:2.5, between 1:1 and 1:2.5, between 1:1.5 and 1:2, or approximately 1:1.8. In the following cases, the ratio of length L6 to distance D1 can be between 2:1 and 1:1, or between 3:2 and 5:4, or approximately 1.4:1.

[0088] In some cases, the length L6 can be adjusted to change one or more of the distances D1, D2, or L4. In some cases, one or more of the distances D1, D2, D3, L3, L5, and L6 can be adjusted to provide an overall reduction or increase in the length L4 of the power tool 100. In some cases, reducing the length L3 can reduce the distance D1 or D2. In some cases, reducing the length L6 can reduce the distance D1 or D2. In some cases, reducing the length L5 or D3 can reduce the distance D1 or D2. In some cases, reducing the distance D1 can reduce the distance D2. Therefore, the dimensions of the power tool 100 can provide a compact power tool in the horizontal direction in a direction parallel to the reciprocating axis 168.

[0089] In some examples, the power tool 100 can be further dimensioned to provide a vertically compact power tool 100 in a direction parallel to the crank axis 136. (Continue to reference) Figure 2The diagram shows the distance D4 (e.g., the seventh distance) between the motor axis 120 and the reciprocating axis 168. Distance D4 is measured in a direction parallel to the crank axis 136. Specifically, distance D4 can be between 10 mm and 30 mm, or between 15 mm and 25 mm, or approximately 18 mm. In some cases, the ratio of distance D4 to inner diameter ID can be between 2:5 and 7:10, or between 1:2 and 3:5, or approximately 11:20. In some cases, distance D4 can be adjusted to increase or decrease the overall height of the power tool 100 measured in a direction parallel to the crank axis 136. For example, gear 128 can be connected to the crankshaft 132 at a height closer to the reciprocating axis 168, and motor 108 can engage gear 128 at a height closer to the reciprocating axis 168. Therefore, distance D4 can be reduced, and the overall height of the power tool 100 can be reduced. Thus, adjusting distance D4 can provide a more compact power tool 100 in the vertical direction.

[0090] In some embodiments, the methods embodying aspects of this disclosure may be used to utilize, manufacture, or install the apparatus or system disclosed herein. Correspondingly, any description herein of a particular feature, function, or intended use of an apparatus or system is generally intended to disclose methods for using such an apparatus for its intended use, methods for otherwise achieving such function, methods for manufacturing related components (or the entire apparatus or system) of such an apparatus or system, and methods for installing the disclosed (or otherwise known) components to support such use or function. Similarly, unless otherwise indicated or limited, any discussion herein of methods for the manufacture or use of a particular apparatus or system (including the installation of said apparatus or system) is intended to inherently include disclosure of the features utilized and the functions achieved by such apparatus or system as embodiments of the invention.

[0091] Furthermore, as used herein, unless otherwise limited or specified, “or” signifies a non-exclusive list of components or operations that may exist in any kind of combination, rather than an exclusive list of components that may exist only as substitutes for each other. For example, a list of “A, B, or C” represents the following options: A; B; C; A and B; A and C; B and C; and A, B, and C. Correspondingly, as used herein, the term “or” is intended to signify an exclusive substitute only when preceded by an exclusive term (such as “either,” “one of,” “only one of,” or “exact one of”). For example, a list of “one of A, B, or C” represents the following options: A, but not B and C; B, but not A and C; and C, but not A and B. A list preceded by “one or more” (and variations thereof) and containing “or” to separate the listed elements represents an option of one or more of any or all of the listed elements. For example, the phrases "one or more of A, B, or C" and "at least one of A, B, or C" represent the following options: one or more A's; one or more B's; one or more C's; one or more A's and one or more B's; one or more B's and one or more C's; one or more A's and one or more C's; and one or more A's, one or more B's, and one or more C's. Similarly, a list preceded by "multiple" (and its variations) and containing "or" to separate the listed elements represents an option of multiple instances of any or all of the listed elements. For example, the phrases "multiple of A, B, or C" and "two or more of A, B, or C" represent the following options: A and B; B and C; A and C; and A, B, and C.

[0092] Furthermore, as used herein, unless otherwise specified or limited, directional terms are for the convenience of discussion with reference to a particular drawing or example, or to indicate spatial relationships relative to a particular other part or context, but are not intended to indicate absolute orientation. For example, references to downward, forward, or other directions, or to top, rear, or other locations (or features), may be used to discuss aspects of a particular example or drawing, but do not necessarily require similar orientations or geometries in all installations or configurations.

[0093] Furthermore, as used herein, unless otherwise limited or specified, “generally parallel” means a direction within ±12 degrees of the reference direction (e.g., within ±6 degrees or ±3 degrees), including end values. Similarly, unless otherwise limited or specified, “generally perpendicular” similarly means a direction perpendicular to the reference direction within ±12 degrees (e.g., within ±6 degrees or ±3 degrees), including end values. Correspondingly, “generally vertical” means generally parallel to a vertical direction defined relative to the reference system (e.g., by default, the direction of local gravity), and “generally horizontal” (relative to the horizontal direction) has a similar derived meaning. Discussion of “lateral” directions relative to the reference direction refers to directions that are clearly not parallel to the reference direction. Correspondingly, some lateral directions may be perpendicular to or generally perpendicular to the relevant reference direction.

[0094] Unless otherwise specifically indicated, the use of ordinal numbers herein is for ease of reference and is generally based on the order in which particular components are presented in the relevant sections of this disclosure. For example, in this regard, names such as “first,” “second,” etc., generally only indicate the order in which the so-called components are introduced into discussion and generally do not indicate or require a particular spatial, functional, temporal, or structural primacy or order.

[0095] The foregoing description of the disclosed embodiments is intended to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be apparent to those skilled in the art from this disclosure, and the principles defined herein can be applied to other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not intended to be limited to the embodiments shown herein, but is accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power tool, comprising: motor; A spindle, the spindle defining a first end having a slot; as well as A crankshaft comprising a counterweight and a crank pin, the counterweight and the crank pin being rotated about a crank axis by the motor such that at least one of the counterweight and the crank pin rotates through the slot.

2. The power tool according to claim 1, wherein, The counterweight includes a first distance and the crank pin includes a second distance greater than the first distance, both of which are measured in a direction perpendicular to the crank axis.

3. The power tool according to claim 1, wherein, The spindle has a second end opposite to the first end, and defines a third distance between the first end and the second end of the spindle; and The spindle is included in an anvil seat portion between the first end and the second end, and is defined at a fourth distance between the anvil seat portion and the first end of the spindle.

4. The power tool according to claim 3, wherein, The ratio of the fourth distance to the third distance is between 1:1.5 and 1:

2.

5. The power tool according to claim 3, further comprising a fifth distance between the crank axis and the second end of the spindle. in, The ratio of the fourth distance to the fifth distance is between 1:1.5 and 1:2.

5.

6. The power tool of claim 3, further comprising an anvil received in the spindle, the anvil defining a drill bit seat portion configured to receive a tool drill bit. in, When the anvil contacts the anvil seat portion, a sixth distance is defined between the drill bit seat portion and the crank axis.

7. The power tool according to claim 6, wherein, The sixth distance is between 130 mm and 160 mm.

8. The power tool according to claim 7, wherein, The average impact energy applied to the anvil is between approximately 7.5 joules and 9 joules.

9. The power tool according to claim 6, wherein, The ratio of the sixth distance to the total length of the power tool measured in a direction perpendicular to the crank axis is between 1:2 and 1:2.

5.

10. The power tool according to claim 6, wherein, The ratio of the third distance to the sixth distance is between 3:2 and 5:

4.

11. The power tool according to claim 6, wherein, The ratio of the sixth distance to the fourth distance is between 9:1 and 6:

1.

12. The power tool of claim 6, further comprising a fifth distance between the crank axis and the second end of the spindle. in, The ratio of the sixth distance to the fifth distance is between 1:1.5 and 1:1.

75.

13. The power tool according to claim 1, wherein, The motor defines the motor axis, and the spindle defines the spindle axis. The ratio of the seventh distance between the motor axis and the spindle axis to the inner diameter of the spindle is between 1:2 and 3:

5.

14. A power tool, comprising: A spindle, wherein the spindle defines an anvil seat portion between a first end and a second end; An anvil, the anvil defining a drill bit seat portion configured to receive a tool drill bit, and the anvil engaging with the anvil seat portion to define a characteristic length of less than about 175 mm between the drill bit seat portion and a first end of the spindle; as well as A crankshaft, which is rotated about a crank axis by a motor, to apply an impact at the anvil with an average impact energy between about 7.5 joules and about 9 joules.

15. The power tool according to claim 14, wherein, The first end of the main shaft defines a slot, and the crankshaft includes a counterweight that rotates through the slot.

16. The power tool according to claim 14, wherein, The length of the spindle chamber, defined between the anvil seat and the first end of the spindle, is between approximately 100 mm and approximately 125 mm.

17. The power tool according to claim 14, wherein, The distance from the crank axis to the first end of the spindle is between approximately 200 mm and approximately 250 mm.

18. The power tool according to claim 15, wherein, The maximum radius of the counterweight is between approximately 20 mm and approximately 25 mm.

19. The power tool according to claim 14, wherein, The inner diameter of the spindle is between approximately 25 mm and approximately 35 mm.

20. A power tool, comprising: motor; A spindle, the spindle defining a first end having a slot and an anvil seat spaced apart from the first end; An anvil, the anvil defining a drill bit seat portion configured to receive a tool drill bit, and the anvil engaging with the anvil seat portion to define a characteristic length of less than about 175 mm between the drill bit seat portion and a first end of the spindle; as well as A crankshaft comprising a counterweight and a crank pin, the counterweight and the crank pin being rotated about a crank axis by the motor such that at least one of the counterweight and the crank pin rotates through the slot.

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