Vertically oriented bending pad spring for tool handle

Abstract

A cushion for a folding knife includes a curved elongate spring to bias a blade of the knife to an open or closed position. The spring may extend in an arc shape from a starting point to a free end within the cutout region of the body of the pad. In one approach, the spring may be J-shaped. The spring may be integrally formed with the cushion, or formed as a separate piece attached to the cushion. The free end may include a shoe to contact a locking stud in the knife handle. The starting point may be located below and in front of the shoe. A spring biases the locking stud forward to lock the blade in the open position. To close the blade, the user moves the locking stud rearward against the spring force of the spring, thereby rotating the blade to the closed position.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 393,099, filed on July 28, 2022, which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of knives, and in particular to a liner for a knives, wherein the liner has an integrated spring. Background Art

[0004] Knives of various designs are available, depending on the needs of different uses. Generally speaking, knives can be constructed with either a fixed blade or a folding blade. Knives with folding blades are more convenient for many applications due to their more compact size. To improve safety and convenience, some knives with folding blades employ a spring mechanism that biases the blade in an open or closed position. A locking mechanism may also be provided to lock the blade in the open position. However, existing spring mechanisms have relatively low wear resistance, take up additional space, and present maintenance issues. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The embodiments of the present disclosure will be more fully understood based on the detailed description given below and the drawings of various embodiments of the present disclosure; however, the detailed description given below and the drawings of various embodiments of the present disclosure should not be construed as limiting the present disclosure to specific embodiments, but are only used for explanation and understanding.

[0006] Figure 1 is a side view of an example cutting tool 100 according to various embodiments.

[0007] Figure 2 According to various embodiments Figure 1 A side view of a portion of the tool including the pad 200.

[0008] Figure 3A is a side view of a portion of an example cutter pad 300 including an integral, vertically oriented elongated spring 310 according to various embodiments.

[0009] Figure 3B According to various embodiments Figure 3A 3. The view in the direction of arrow 360. This view depicts two of the liners 300, namely, the liners 300a and the liners 300b, the locking stud 120, and the hub 103.

[0010] As mentioned, two pads of the same type are usually provided in the handle, one on each side of the tang.

[0011] Figure 3C Depicted according to various embodiments Figure 3A A perspective view of a gasket 300 showing the cross-sectional thickness.

[0012] Figure 4 is a side view of a portion of an example liner 370 according to various embodiments, the liner 370 and Figure 3A The liner 300 is similar, but wherein the liner includes an opening 380 .

[0013] Figure 5 An example cushion design 500 is depicted in which the spring 510 is a separate piece attached to the cushion 540 , in accordance with various embodiments.

[0014] Figure 6 Depicted is a graph showing the range of forces on an integral elongated spring having a less preferred spring design according to various embodiments.

[0015] Figure 7 Depicted is a graph showing the range of forces on a one-piece elongated spring with a more preferred spring design according to various embodiments.

[0016] Fig. 8A A side view of a cushion 800 is depicted wherein a J-shaped spring 805 has a stop 810 according to various embodiments.

[0017] Figure 8B Depicted according to various embodiments Fig. 8A A side view of the pad 800 as manufactured, with the tab 820 added for stability.

[0018] Fig. 9 Depicted according to various embodiments Fig. 8A A pad 800 with a spring in a locked load position and a maximum load position.

[0019] Fig.10 According to various embodiments Figure 2 Side view of a tang 1000 with a hook in a knife of FIG.

[0020] Fig.11 According to various embodiments Figure 2 Side view of the tang 1100 without the hook in the knife.

[0021] Fig. 12A Depicted according to various embodiments Fig. 8A A pad 800 is shown showing various features.

[0022] Fig. 12B Depicted according to various embodiments Fig. 8AA pad 800 is shown showing various features.

[0023] Fig.13A Depicted are graphs of spring constant versus total spring vertical height for various pad designs according to various embodiments.

[0024] Fig. 13B Depicted are graphs of spring constant versus total spring horizontal width for various pad designs according to various embodiments.

[0025] Fig. 13C Depicted are graphs of spring constant versus total spring arc length for various pad designs according to various embodiments.

[0026] Fig.13D Depicted are graphs of spring constant versus minimum bend radius for various pad designs according to various embodiments.

[0027] Fig.13E Depicted are graphs of spring constants versus distance from a starting point to a shoe member for various pad designs according to various embodiments.

[0028] Fig.13F Depicted are graphs of spring constant versus starting angle for various pad designs according to various embodiments.

[0029] Figure 13G Depicted are graphs of spring constant versus starting point horizontal offset for various pad designs according to various embodiments.

[0030] Fig.13H Depicted are graphs of spring constant versus starting point vertical offset for various pad designs according to various embodiments.

[0031] Fig.13I Depicted is a graph of the ratio of spring vertical height to total cushion vertical height versus spring constant for example cushions according to various embodiments.

[0032] Fig.13J Depicted according to various embodiments Fig.13I A graph of the ratio of the arc length of an example pad to the total pad vertical height versus the spring constant.

[0033] Figure 13K An example table depicting spring constant and stress values ​​as a function of spring size according to various embodiments.

[0034] Figure 13L Depicted are various embodiments of Figure 13K A graph showing the relationship between the spring constant and the thickness of the pad and the vertical height of the spring, consistent with the table above.

[0035] Figure 13MDepicted are various embodiments of Figure 13K A graph showing the relationship between stress and pad thickness and spring vertical height consistent with the table.

[0036] Fig.14 Example pad designs having different minimum bend radii are depicted according to various embodiments.

[0037] Fig.15 Example pad designs with different starting angles are depicted according to various embodiments.

[0038] Fig.16 Depicted are example pad designs according to various embodiments.

[0039] Fig.17 Example pad designs of varying efficiencies are depicted according to various embodiments. DETAILED DESCRIPTION

[0040] In the following detailed description, reference is made to the accompanying drawings which form a part of this description and in which embodiments that can be practiced are shown by way of illustration. It should be understood that other embodiments can be utilized and structural or logical changes can be made without departing from the scope. Therefore, the following detailed description should not be taken in a limiting sense, and the scope of the embodiments is defined by the appended claims and their equivalents.

[0041] Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding the embodiments; however, the order of description should not be construed as to imply that these operations are order dependent.

[0042] The description may use perspective-based descriptions, such as up / down, back / front, and top / bottom. Such descriptions are only used to facilitate discussion and are not intended to limit the application of the disclosed embodiments.

[0043] The terms "couple" and "connect" and their derivatives may be used. It should be understood that these terms are not intended to be synonymous with each other. On the contrary, in a particular embodiment, "connect" may be used to indicate that two or more elements are in direct physical contact with each other. "Coupling" may mean that two or more elements are in direct physical contact. However, "coupling" may also mean that two or more elements are not in direct contact with each other, but still cooperate or interact with each other.

[0044] For the purposes of the description, a phrase in the form “A / B” or in the form “A and / or B” means (A), (B), or (A and B). For the purposes of the description, a phrase in the form “at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C). For the purposes of the description, a phrase in the form “(A)B” means (B) or (AB), that is, A is an optional element.

[0045] The specification may use the terms "embodiment" or "embodiments", which may each refer to one or more embodiments of the same or different embodiments. In addition, the terms "including", "comprising", "having", etc. used in relation to the embodiments are synonymous.

[0046] As mentioned at the outset, there are various challenges in providing a spring mechanism for a folding knife. One approach is to use a horseshoe-shaped (or omega-shaped, referring to the Greek symbol "Ω") locking spring that is attached to two pads in the handle of the knife to bias a locking rod that moves in a slot when the blade is opened and closed. For example, see U.S. Pat. No. 9,862,104, issued on January 9, 2018 and incorporated herein by reference, which discloses a horseshoe-shaped locking spring that is attached to a pad to bias a locking rod. Other approaches include a pad locking spring that extends along the length of the handle, typically located on one side of the handle, and a safety spring that extends along the length or edge of the handle. However, these approaches have disadvantages in terms of wear resistance, space requirements, and maintenance issues.

[0047] The device described herein solves the above-mentioned problems and other problems.On the one hand, the pad for folding knife comprises a vertically oriented spring, which is a part of one or two pads in the knife handle.The vertically oriented spring is curved and elongated, and can be a J-shaped spring, for example, but other shapes are also possible.The spring can be formed by the same metal sheet or other material forming the pad, or the spring can be formed as a separate piece, which is attached to the pad and fixed to the pad, such as attached to the pad and fixed to the pad in a friction fit.The spring can have the characteristics as described herein, when opening and closing the blade, the characteristics provide a good feeling for the user, for example, based on factors such as the amount of tension required to open or close the blade, provide a good feeling for the user.The spring can be arranged to bias the locking stud when the blade is opened and closed, and the locking stud moves in the slot in the handle, wherein the locking stud contacts the tang of the blade.Therefore, for safety reasons, the spring will bias the blade towards the open and closed position.

[0048] The pad design described herein is also expected to have a significantly increased service life, allowing a significantly greater number of opening / closing cycles of the knife blade than previous designs.

[0049] Since the spring is bonded to the pad or attached to the pad in a cutout region in the plane of the pad, the pad design also allows for a thinner handle width. In addition, with a vertically oriented spring, the horizontal length of the pad can be reduced, allowing for a variety of design options for the handle.

[0050] The above and other advantages will become more apparent in light of the following discussion.

[0051] Figure 1 is a side view of an example knife 100 according to various embodiments. The knife includes a blade 101 and a handle 102 and extends along a longitudinal axis LA. The finger support 105 of the handle includes a pivot point PP or axis about which the blade can rotate, and a slot 115 in which a locking stud 120 can move in a forward or rearward direction. In one approach, the locking stud is in a forward direction when the blade is in an open or closed position, and the locking stud is temporarily moved to a rearward direction when the blade is in an intermediate or partially open position. In particular, the locking stud can interact with the tang of the blade to lock the blade in an open position or allow the blade to rotate to a closed position. The spring mechanism provides a force on the tang via the locking stud and can assist the user in opening or closing the blade.

[0052] The forward direction may be, for example, in a direction toward the front of the tool or the tip of the blade, parallel to the longitudinal axis. The rearward direction may be, for example, in a direction opposite to the forward direction, toward the rear of the tool. With reference to an xy coordinate system, the forward direction may be in the x direction, and the rearward direction may be in the -x direction. The vertical direction may be the y direction.

[0053] The user's thumb can engage the thumb button 130 to help move the blade to the open or closed position. The handle includes a plurality of fasteners 140 to 143 for securing opposite sides of the handle together. The fastener 140 also serves as a stop pin.

[0054] Folding blade knives can be used for a variety of household, cooking and outdoor purposes. Such knives are sized to fit the hand of an average user and, for example, can be about 4 inches to 5 inches (101 mm to 127 mm) long when the blade is closed, or about 7 inches to 8 inches (178 mm to 203 mm) long when the blade is open.

[0055] Figure 2 According to various embodiments Figure 12 is a side view of a portion of a knife including a liner 200. Typically, two liners of the same type are provided in the handle, one on each side of the tang. The liners are attached to the handle shell or cover using fasteners 220. The blade 101 includes a tang 210, which is mounted on the hub 103 to pivot about a pivot point PP. The tang includes a top shoulder 211 that rests against the fastener / stop pin 140 when the blade is in the fully open position. The stop pin prevents the blade from rotating clockwise. The tang also includes a bottom shoulder 214. The tang also includes a straight ramp portion 212 that contacts the locking stud 120 when the blade is in the fully open position. The locking stud prevents the blade from rotating counterclockwise as long as the locking stud is in the forward position in the slot. A spring mechanism, not shown, biases the locking stud to the forward position to ensure that the blade remains securely locked when in the open position.

[0056] When the user manually moves the locking stud to the rearward position, as depicted by locking stud 120r, the tang is free to rotate to allow the blade to move to the closed position. When the tang is rotated counterclockwise, the rounded portion 213 of the tang contacts the locking stud so that the locking stud does not prevent the rotation of the blade. The locking stud is pushed backward by the rounded portion 213 of the tang, causing the force on the spring mechanism to increase. The forward position of the locking stud is the locked load position because the blade is locked in this position. The spring mechanism can apply a relatively small force to the locking stud to keep it in the forward locked load position. The rearward position of the locking stud is the maximum (max) load position because the load on the spring mechanism is the largest. CLR refers to the cyclic load range, which is the difference between the maximum load and the locking load.

[0057] The following definitions can be made:

[0058] "Detent Load" or "Lock Load": The sum of the forces applied by the two springs of the two pads to the locking stud in the locked load position. This includes preload and running-in tolerances.

[0059] "Maximum Load": The sum of the forces applied to the locking stud by the two springs in the maximum load position. This is when the locking stud is in the rearmost position in the tool handle and includes any overtravel at the ends.

[0060] “Cyclic Load Range (CLR)”: The difference between maximum load and lockout load, i.e. (Spring Constant) X (Travel).

[0061] “Total Stroke Length” or “Stroke”: The distance the locking stud travels from the locked load position to the maximum load position.

[0062] Figure 3A3 is a side view of a portion of an example tool liner 300 according to various embodiments, the tool liner 300 includes an integral, vertically oriented elongated spring 310. In one approach, two such liners are provided in the tool handle, one on each side. The liner includes an opening 305 for a stop pin and an opening 335 for a hub. A pivot point PP is also depicted.

[0063] In this example, the spring 310 is integrally formed as one piece with the gasket from sheet metal, e.g., the curved elongated spring is integrally formed as one piece with the body of the gasket. In other examples, the spring is formed separately from the gasket and then attached to the gasket during its manufacture, e.g., the curved elongated spring is a separate piece attached to the body of the gasket.

[0064] In this example, the spring is generally J-shaped, but may have other shapes. The spring may generally be curved. The spring may be oriented vertically because its height is greater than its total horizontal width. The spring extends from a tie point or starting point 355 in a cutout area 340 in the body of the pad. This point may be located below and in front of the pivot point. The spring, also referred to as a lever arm, extends along an arc from its starting point, extending downward to a point just below the pivot point, and then upward to a point above the pivot point and to the right of the pivot point. Note that the front of the knife handle is on the left in this figure, and the rear of the knife handle is on the right. This convention also applies to other pad figures in this article. In this example, the spring is depicted in three positions. Spring 311 represents the stamping position in which the spring is formed. The spring is not under load in this position. The spring includes a shoe-shaped member 311a having a face 311b, on which the locking stud may rest. Spring 312 represents a locked load position, in which the spring is subjected to a relatively small load while the locking stud 120 rests against the face of the shoe. Spring 313 represents a maximum load position, in which the spring is subjected to a maximum load while the locking stud 120 rests against the face of the shoe.

[0065] In an example embodiment, the triangular area 350, referred to as the locking triangle, is substantially intact to ensure strength. The liner includes an inner portion 300int located on one side of the cutout area and adjacent to the opening 335, and an outer portion 300ext located on the opposite side of the cutout area. The cutout may extend to the outer periphery of the liner without being enclosed. For example, see Figure 4 .

[0066] The stop 320 is a protrusion in the wall 330 of the cutout to limit the rearward movement of the spring and shoe. In this example, the protrusion extends toward the front of the cutter. All contact of the spring with the pad should be behind the shoe. It is not desirable for the middle of the spring to contact the pad. The spring can extend to the outer periphery in the deformed (maximum load) state, but not in the neutral (locked load) state.

[0067] Figure 3B According to various embodiments Figure 3A 360. This view depicts two curved elongated pads in the curved elongated pad 300, as first pad 300a and second pad 300b, respectively, the locking stud 120 and the hub 103. As mentioned, two pads of the same type can be provided in the handle, one pad on each side of the tang. The locking stud and the hub extend through the pads and can be slightly longer than the spacing sp between the pads. The pads are spaced apart from each other by sp. The locking stud can extend outward from the pads to allow the user to operate the locking stud with their thumb when closing the blade. The hub can be fixed to the pads, while the locking stud protrudes beyond the pads and can be moved forward and backward with minimal friction.

[0068] Figure 3C Depicted according to various embodiments Figure 3A 300, showing the cross-sectional thickness (Th). As mentioned, in one possible approach, the spring may be stamped from the same sheet metal as the body of the liner, such that the spring and the body of the liner have the same thickness. The width (w) of the spring is also depicted. Alternatively, the spring and the body of the liner may also have different thicknesses.

[0069] Figure 4 is a side view of a portion of an example liner 370 similar to Figure 3A 300, but wherein the liner includes an opening 380. As mentioned, the cutout area 390 of the liner can extend to the outer periphery of the liner without enclosing around the spring. This approach can allow for weight reduction and provide room for design changes. The spring has a bend point 450, which refers to the point on the spring where there is a local minimum in the bend radius.

[0070] Many example design requirements can be set for the spring. For example, with respect to stress, the liner can be required to withstand 100,000 open-close cycles without deformation, and to withstand one open-close cycle during assembly without deformation. Deformation refers to the spring arm being stressed to the point where permanent plastic deformation occurs. An example material for the liner is a heat treated metal, such as 410SS. This refers to alloy 410 (UNS S41000), a martensitic stainless steel sheet containing 12% chromium. However, many other materials are possible. In one approach, the metal is sheet metal. In addition, when the spring is formed separately from the liner, the spring can be made of a different material than the material of the liner.

[0071] In a finite element analysis study of a device using 41OSS metal, an example yield strength of 186 kilopounds per square inch (ksi) (1,282 MPa) was used as the limit. An ultimate strength of 216 ksi (1,489 MPa) was also used.

[0072] Another example design requirement involves displacement / total stroke length. For example, locking stud total stroke: This is the tang displacement plus a minimum of 0.015" clearance. An example stroke length is 0.1028" (0.0678" of travel to lock engagement + 0.020" diameter increase for suckback + 0.015" minimum additional clearance). The suckback refers to the action of the spring biasing the blade toward the closed position. Note that other shaft lock designs have a total stroke length of approximately 0.200" (longer stroke, more excess travel / extra clearance afterwards). For optimal suckback effects, a larger stroke length may be required.

[0073] Regarding the spring rate, also called the spring constant, lower values ​​are better to produce a similar feel at the locked load and the maximum load. Example A typical target is 10 lbs / in (1751 N / m) total or 5 lbs / in (875 N / m) per pad. Spring rates are usually discussed as a total based on the use of two pads in a knife handle. The spring rates in this document follow this convention.

[0074] Regarding force design requirements, one approach is to start with a lockout load target of approximately 1.0lb (44.4N). This can be increased if necessary. In one approach, the CLR (due to spring design and total stroke length) is ideally less than 1.0lb (44.4N). With the lockout load target and CLR set, the maximum load can then be adjusted as needed within the acceptable stress range. Typically, the force is a minimum of 0.15lb (0.67N) per pad (0.3lb or 1.33N total) in the locked load state.

[0075] Other desirable design requirements include corrosion resistance, ease of assembly, reasonable manufacturing / tooling costs, the ability of the locking stud to move along the slot without excessive friction, and ensuring that the locking stud does not fall below the top edge of the liner opening or slot. That is, the locking stud should be held against the top wall / edge of the cutout area of ​​the liner by the shoe of the spring.

[0076] Figure 5 An example pad design 500 is depicted according to various embodiments, wherein the spring 510 is a separate piece attached to the pad 540. Instead of combining the spring with the pad as a single piece, the spring can be stamped from a sheet of metal separate from the stamped pad. The spring is then installed into the pad with a close fit, such as with a friction fit or press fit, or otherwise attached to the pad. This can provide some advantages, such as allowing the spring to be formed of a different material than the material of the pad and / or have a different thickness than the thickness of the pad. Different materials and / or thicknesses can be designed to optimize the properties of the spring, such as spring constant and durability. In addition, it is easier to stamp the spring and pad separately.

[0077] Potentially, the spring can be replaced after the knife is manufactured, such as for repair or to allow the user to customize the characteristics of the knife. For example, the user may want to have a larger or smaller force when opening and closing the blade by installing a spring with a larger or smaller spring constant, respectively. In this design, the spring can be replaceable.

[0078] In this example, the spring is elongated and curved and has three bending points 550 , 551 and 552 .

[0079] The spring 510 includes an end portion 510a that fits into a correspondingly shaped opening 541 in the liner at the starting point 555 of the spring. The spring also includes a free portion 510b extending from the starting point to the free end. At the free end, the shoe 520 includes a groove or notch 521 at its face to hold the locking stud 120. The groove faces upward so that the spring tends to hold the locking stud against the top wall 542 of the liner to prevent a click when the locking stud falls off the top wall and then rebounds to the top wall. A stop 530 is also depicted to limit the rearward movement of the spring in the maximum load position. The spring is shown in the locked load position.

[0080] Figure 6A graph is depicted showing the range of forces on a one-piece elongated spring having a less preferred spring design according to various embodiments. Such a spring design has a relatively large CLR, few options in obtaining the force required to bias the locking stud, and requires operation at or near the maximum stress capacity of the spring. The graph shows that the locking load (LL) force (left bar extends from 0 lb to 0.9 lb or from 0 N to 4.0 N) is approximately 0.9 lb (4.0 N), the CLR force is approximately 1.7 lb or 7.5 N (middle bar extends from 0.9 lb to 2.6 lb or from 4.0 N to 11.5 N), and the remaining maximum stress (MS) margin is only about 0.1 lb or 0.44 N (right bar extends from 2.6 lb to 2.7 lb or from 11.5 N to 12.0 N).

[0081] Figure 7 A graph showing the range of forces on a one-piece elongated spring with a more preferred spring design according to various embodiments is depicted. A good spring design has a relatively small CLR, has multiple options in obtaining the force required to bias the locking stud, and avoids the need to operate at or near the maximum stress capacity of the spring. The graph shows that the locking load force (left bar extends from 0 lb to 1.0 lb or from 0 N to 4.4 N) is approximately 1.0 lb (4.4 N), the CLR force is approximately 0.8 lb or 3.5 N (middle bar extends from 1.0 lb to 1.8 lb or from 4.4 N to 8.0 N), and the remaining maximum stress margin is approximately 0.5 lb or 2.2 N (right bar extends from 1.8 lb to 2.3 lb or from 8.0 N to 10.2 N). Therefore, in the locked load position of the spring, the spring force on the locking stud is 1.0 lb (4.4 N), and in the maximum load position of the spring, the spring force on the locking stud is 1.8 lb (8.0 N). The spring can be designed to set the locking load force or the maximum load force at the desired level. The maximum stress margin represents the selectable load range.

[0082] The design process can proceed as follows. First, start with a lockout load target of approximately 1.00 lb (4.4 N). Second, aim to minimize CLR by, for example, minimizing the cross-sectional area of ​​the lever arm, maximizing the lever arm vertical length and the total arc length, and minimizing travel, such as through blade tang design. Third, if the stress at maximum load exceeds the stress limit (e.g., 186 ksi or 1,282 MPa), adjust the above process. For heavy blades, the lockout load target may have to be increased to achieve the desired suck-back to the closed position.

[0083] Fig. 8AA side view of a liner 800 is depicted according to various embodiments, wherein a J-shaped spring 805 has a stop 810. As noted, it is desirable to have a stop to limit the maximum deflection of the spring. The stop allows for a maximum displacement, but no greater, so that it does not deform during assembly, e.g., the spring arm is not stressed to the point of permanent plastic deformation, and instead, the spring arm is able to bend back to its original shape. In this example, the stop is located on the rear side of the shoe. In other examples, the stop is part of the liner, such as Figure 3A The stopper 320 is provided.

[0084] Figure 8B Depicted according to various embodiments Fig. 8A 800 during manufacture, with a tab 820 added for stability. The tab can be stamped out of a metal sheet with a spring. The tab secures the spring during manufacture and is subsequently removed, for example by cutting.

[0085] Fig. 9 Depicted according to various embodiments Fig. 8A The liner 800 is shown with the spring in the locked load position and the maximum load position. The stopper 810 is located at the rear side of the J-shaped spring 805 (facing the rear end of the handle) instead of at the rear wall of the liner. The locked load position is represented by the spring 805 and the locking stud 120, and the maximum load position is represented by the spring 805a and the locking stud 120r.

[0086] and Figure 3A The flat shoe piece face 910, 930 helps to hold the locking stud against the top wall of the slot compared to the concave shoe piece face of the locking stud. Due to the flat shoe piece face, when the locking stud moves rearward, the locking stud will roll the shoe piece face upward. This will hold the locking stud against the top surface of the slot. This design also produces a greater locking stud movement relative to the spring deflection, thereby producing a "softer" spring constant without increasing the spring stress.

[0087] Additionally, a liner is formed of 920 material in the upper right corner of the opening to prevent the locking stud from sliding past the shoe.

[0088] on the contrary, Figure 3A The design may produce a clicking sound because the locking stud sits on the concave surface of the shoe, and when the shoe is pulled back, the locking stud may pull away from the top wall of the liner and then jump back to hit the wall.

[0089] Fig.10 According to various embodiments Figure 21. A side view of a tang 1000 with a hook in a knife of FIG. In this tang design, the hook 1001 may have a tendency to catch or hook the locking stud 120. This tends to pull the locking stud away from the top wall of the slot, thereby creating a potentially undesirable rattling sound when the knife is in use.

[0090] Fig.11 According to various embodiments Figure 2 A side view of a tang 1100 without a hook in a knife of FIG. This is an improved blade tang design that can be solved by rounding the tip of the hook to provide a rounded area 1101 Fig.10 The clicking sound problem in the

[0091] Fig. 12A Depicted according to various embodiments Fig. 8A 800 showing various features. The spring radius, also known as the bend radius, varies at different points along the spring. Fig. 12A Different bend radii r1 to r3 at three example points are shown. The steeper the bend, the shorter the radius, and the flatter the bend, the longer the radius. r1 is the radius at the starting point of the spring. The spring will have a minimum bend radius at some point along its length. In some cases, the minimum bend radius is at or near the bottom of the spring. At the minimum bend radius, stresses are concentrated, and this is what drives the spring constant and stress. Some springs have a relatively constant bend radius over most of the length, and some springs have one main bend area with a constant radius and intentionally have a small bend radius in one area to facilitate a local bend point. In all of these cases, the minimum bend radius is still important.

[0092] The origin of the spring refers to the point on the shoe face that contacts the locking stud. This could be, for example, the center of the shoe face. The shoe is located at the free end (FE) of the spring. The rear side of the shoe includes a protruding stop (PS). The shoe angle is the angle of the shoe face relative to the vertical, in a clockwise direction from the vertical. The horizontal direction is considered to be relative to the longitudinal axis (LA) of the tool handle (see Figure 1 ), for example, the longitudinal axis (LA) extends along the length of the tool handle, and the vertical (y-axis) is considered to be a direction perpendicular to the horizontal direction (x-axis) and the longitudinal axis. The starting point vertical offset is the vertical distance between the starting point of the spring and the origin of the shoe-shaped member surface. The starting angle (OA) is the angle of a straight line drawn between the starting point of the spring and the origin of the shoe-shaped member surface relative to the vertical line in the clockwise direction in the figure. In this example, the starting angle is approximately 230 degrees, for example greater than 225 degrees. In this example, the number of bends in the spring is one. In other examples, the spring has multiple bends in opposite directions. See, for example Fig.16The pad design 1620. The starting point horizontal offset is the horizontal distance between the starting point 1201 of the spring and the origin 1202 of the shoe-shaped member surface.

[0093] Fig. 12B Depicted according to various embodiments Fig. 8A 800, which shows various features. The total vertical height of the spring is the vertical distance between the lowest point (BP) of the spring and the origin of the shoe face. The total horizontal width of the spring is the horizontal distance between the starting point and the rearmost point (rp) of the spring. The total spring arc length (AL) is the distance along the spring from the starting point to the origin of the shoe face.

[0094] Several observations can be made regarding optimizing springs and liners. First, thinner and narrower springs have lower spring constants, and lower stresses at the maximum load location, which is desirable. The spring constant is a strong function of the lever arm thickness and width. Reducing the width reduces stresses, while changing the thickness does not affect stresses. One approach is to use the minimum spring thickness and width, as these optimize the CLR at a low level while also reducing stresses, unless there is another reason to increase the thickness and / or width. The minimum spring thickness and width are based on the thickness of the original sheet material.

[0095] Another observation is that a spring with a softer (more gradual) bend point results in a lower CLR and similarly lower stress, while a spring with a sharper (less gradual) bend point results in a lower CLR but higher stress. The optimal spring shape will depend on the form factor of the tool. In some cases, a minimum bend radius in the range of about 2 mm (0.08") to about 5 mm (0.20") works well. Note that the bend radius can vary along the spring so that the minimum bend radius is the sharpest bend point along the arc length of the spring. Therefore, although stress will increase, setting a steeper bend point will result in a lower spring constant.

[0096] Another observation is that a higher spring start point and a larger spring arc length contribute to a lower spring constant.

[0097] Another observation is that greater vertical height significantly reduces the spring constant. In fact, increasing the vertical height of the spring is the single largest factor in reducing the spring constant. The effect of vertical height is greater than the effect of starting point in reducing the spring constant. However, if the greater vertical height causes the minimum bend radius to be too flat (too large), the spring constant may increase. For example, see Fig.14 The pad design in the.

[0098] The following discussion relates to test data for J-springs.

[0099] exist FIG. 13A to FIG. 13JIn the diagram, the circled points represent a pad / spring thickness of 0.040" (1.016 mm) and a spring width of 0.025" (0.635 mm), and the other points represent a pad / spring thickness of 0.050" (1.270 mm) and a spring width of 0.030" (0.762 mm). Spring constants are in pounds per inch or N / m. Length dimensions are in inches or mm.

[0100] Fig.13A A graph of the spring constant versus total spring vertical height for various pad designs according to various embodiments is depicted. The data shows that there is a very strong correlation between the spring vertical height and the spring constant. In particular, the spring constant decreases as the vertical height increases.

[0101] Outlier 1300 is caused by a flat bend radius and a starting angle close to 180 degrees.

[0102] Spring constants range from 5 lb / in to 19 lb / in or 3327 N / m, and overall vertical heights range from 0.400 in to 1.200 in or 10 mm to 30 mm.

[0103] Fig. 13B Depicted are graphs of spring constants versus total spring horizontal width for various pad designs according to various embodiments. There is a small but not strong correlation between horizontal width and spring constant. In particular, spring constant decreases as horizontal width increases.

[0104] Spring constants range from 5 lb / in to 19 lb / in or 875 N / m to 3327 N / m, and horizontal widths range from 0.300 in to 0.750 in or 7.6 mm to 19 mm.

[0105] Fig. 13C Depicted is a graph of spring constant versus total spring arc length for various pad designs according to various embodiments. There is a very strong correlation between arc length and spring constant. In particular, spring constant decreases as arc length increases. Outlier 1310 is caused by short vertical height.

[0106] Spring constants range from 5 lb / in to 19 lb / in or 875 N / m to 3327 N / m, and total arc lengths range from 0.600 in to 2.000 in or 15 mm to 51 mm.

[0107] Fig.13DDepicted are graphs of spring constants versus minimum bend radius for various pad designs according to various embodiments. There is a strong correlation between the minimum bend radius and the spring constant. In particular, the spring constant decreases as the bend radius decreases. Point 1320 illustrates how vertical height can cause differences between springs with the same minimum bend radius. Points 1325 have better performance because they have very high vertical heights that exceed the flatter bend radius.

[0108] Spring constants range from 5 lb / in to 19 lb / in or 875 N / m to 3327 N / m, and bend radii range from 0.000 in to 1.000 in or 0 mm to 25 mm.

[0109] Fig.13E Plotted are spring constants versus distance from the starting point to the shoe member for various pad designs according to various embodiments. There is no correlation, indicating that distance is not an important variable.

[0110] Spring constants range from 5 lb / in to 19 lb / in or 875 N / m to 3327 N / m, and distances range from 0.400 in to 1.200 in or 10 mm to 30 mm.

[0111] Fig.13F A graph of spring constant versus starting angle for various pad designs according to various embodiments is depicted. There is a correlation between the starting angle and the spring constant. In particular, the spring constant decreases as the starting angle increases. Outliers 1330 and 1335 are in a disadvantageous position due to another key variable, for example, these two points represent very short spring vertical heights.

[0112] Spring constants range from 5 lb / in to 19 lb / in or 875 N / m to 3327 N / m, and starting angles range from 180 degrees to 250 degrees.

[0113] Figure 13G A graph depicting the relationship between the spring constant and the horizontal offset of the starting point for various pad designs according to various embodiments is shown. There is a small but not strong correlation between the horizontal offset of the starting point and the spring constant. In particular, the spring constant decreases as the horizontal offset of the starting point increases.

[0114] Spring constants range from 5 lb / in to 19 lb / in or 875 N / m to 3327 N / m, and horizontal deflections range from 0.200 in to 0.700 in or 5 mm to 18 mm.

[0115] Fig.13HPlotted are spring constants versus starting point vertical offset for various pad designs according to various embodiments. There is no correlation, indicating that starting point vertical offset is not a significant variable.

[0116] Spring constants range from 5 lb / in to 19 lb / in or 875 N / m to 3327 N / m, and vertical deflections range from 0.100 in to 1.100 in or 3 mm to 28 mm.

[0117] Fig.13I A graph of the ratio of spring vertical height to total cushion vertical height versus spring constant is depicted for example cushions according to various embodiments. There is a strong correlation between the ratio and the spring constant. In particular, the spring constant decreases as the ratio increases. In general, a ratio greater than 0.4 favors low spring constants. Higher than 0.5 is even better. There is no upper limit; the higher the ratio, the better. In one approach, the total vertical height represents the maximum vertical extent of the cushion, with the vertical direction being perpendicular to the longitudinal axis.

[0118] In an example implementation, a ratio of a vertical height of the curved elongated spring to a vertical height of the pad is at least 0.4 or 0.5.

[0119] Spring constants range from 5 lb / in to 30 lb / in or 875 N / m to 5253 N / m, and ratios range from 0.30 to 0.75.

[0120] Fig.13J Depicted according to various embodiments Fig.13I A plot of the ratio of the arc length to the total vertical height of an example pad versus the spring constant. There is a strong correlation between the ratio and the spring constant. In particular, the spring constant decreases as the ratio increases. In general, a ratio greater than 0.5 favors low spring constants. Higher than 0.6 is even better. There is no upper limit; the higher the ratio, the better.

[0121] In an exemplary implementation, the ratio of the arc length of the curved elongated spring to the vertical height of the pad is at least 0.5 or 0.6.

[0122] Spring constants range from 5 lb / in to 30 lb / in or 875 N / m to 5253 N / m, and ratios range from 0.40 to 1.20.

[0123] Figure 13KAn example table depicting the variation of spring constant and stress values ​​with spring size according to various embodiments is shown. Data was obtained from springs with vertical heights of 0.53" (13 mm), 0.59" (15 mm), 1.00" (25 mm), and 1.08" (27 mm), and summarized in the table for springs with vertical heights of 0.5" (13 mm), 0.7" (18 mm), 0.9" (23 mm), and 1.1" (28 mm).

[0124] The first column depicts the spring dimensions expressed as thickness (th) x width (w) in inches (in.) and mm, the second through fifth columns depict the spring constants for different vertical heights in lb / in and N / m, and the sixth through ninth columns depict the spring stresses at a displacement of 0.150″ (3.8 mm) for different vertical heights in ksi and MPa.

[0125] Pad thicknesses considered include 0.030″ (0.762mm), 0.040″ (1.016mm), 0.050″ (1.270mm), 0.060″ (1.524mm), and 0.070″ (1.778mm). These thicknesses refer to the finished pad thickness, not the raw material thickness. Spring width varies with pad thickness (from 0.020 inches to 0.040 inches, or 0.508mm to 1.016mm) because this is a typical manufacturing capability. For example, the ideal spring constant range is 3.0 lbs / in to 15.0 lbs / in (525N / m to 2626N / m).

[0126] In this example, the maximum allowable stress is 186 ksi or 1,282 MPa. A constant total displacement of 0.150″ or 3.8 mm is used for the stress calculation (maximum load position, including preload).

[0127] Generally speaking, when the spring vertical height is larger, the spring constant is smaller, and when the thickness and width are larger, the spring constant is larger. Moreover, when the spring vertical height is larger, the stress is smaller, and when the thickness and width are larger, the stress is larger.

[0128] Figure 13L Depicted are various embodiments of Figure 13KA graph showing the relationship between the spring constant and the change in pad thickness and the vertical height of the spring is consistent with the table above. Curves 1350 to 1353 represent spring vertical heights of 0.5" (13mm), 0.7" (18mm), 0.9" (23mm), and 1.1" (28mm), respectively. The ideal range of spring constants is, for example, about 3lbs / in to 15lbs / in (525N / m to 2626N / m), about 2lbs / in to 25lbs / in (350N / m to 4378N / m), or about 5lbs / in to 20lbs / in (875N / m to 3502N / m). In general, the effect of pad thickness on the spring constant is as great as or even greater than the effect of vertical spring height on the spring constant. The shorter the spring, the more sensitive it is to pad thickness. Given the correct pad thickness, all spring heights can achieve a good spring constant. However, given the theoretically possible range, not all spring thicknesses / widths can be manufactured in a practical manner. As Figure 13K As shown in the table, the spring width varies with the spring thickness.

[0129] Figure 13M Depicted are various embodiments of Figure 13K Graphs 1360 through 1363 show stress as a function of pad thickness and spring vertical height consistent with the table above. Curves 1360 through 1363 represent spring vertical heights of 0.5″ (13mm), 0.7″ (18mm), 0.9″ (23mm), and 1.1″ (28mm), respectively. For example, the ideal stress range is below 186 ksi or 1,282 MPa. In general, taller springs can be below the stress limit at any pad thickness. The sensitivity to pad thickness is roughly the same for all spring heights. However, as with the spring constant, not all spring thicknesses / widths can be manufactured in a practical manner given the theoretically possible range. Spring width varies with spring thickness.

[0130] Fig.14 Example pad designs with different minimum bend radii are depicted according to various embodiments. As mentioned, a softer (flatter) spring bend point results in a lower CLR and similarly lower stress, while a sharper (less flat) spring bend point results in a lower CLR but higher stress. Pad design 1400 has a minimum bend radius (MBR) of 4 mm (0.16") at bend point 1401, which is within the guideline range of about 2 mm (0.08") to about 5 mm (0.20"). Pad design 1410 has a relatively small or sharp minimum bend radius of 1.6 mm (0.06") at bend point 1411, which is less than the guideline value. This design may result in excessive stress in the spring.

[0131] Additionally, as mentioned above, a greater vertical height can significantly reduce the spring constant. However, if the bend radius is too flat, the spring constant may increase. For example, pad design 1420 has a relatively tall spring arm, but at bend point 1421, the minimum bend radius is relatively large (16mm or 0.63"), so the spring constant is advantageously relatively low. Pad design 1430 has a very large minimum bend radius (23mm or 0.90") at a nearly flat bend point 1431, so the spring constant is disadvantageously increased.

[0132] Pad designs 1440 and 1450 do not have a steep bend radius, but are still good designs. Pad designs 1440 and 1450 have minimum bend radii of 6.4 mm (0.25") and 7.9 mm (0.31") at bend points 1441 and 1451, respectively. In some cases, a minimum bend radius of about 2 mm (0.08") to about 8 mm (0.31") may be used. A minimum bend radius of less than about 8 mm (0.31"), 10 mm, or 12 mm may be used. In some cases, the minimum bend radius is in the range of about 2 mm (0.08") to about 8 mm (0.31"), or in the range of about 2 mm (0.08") to about 10 mm (0.39") . These ranges are suitable for folding knives sized to fit the hands of an average user.

[0133] The spring is shown in a locked load position and a maximum load position for pad designs 1400, 1410, 1420, 1440 and 1450. For pad design 1430, the spring is shown in a locked load position.

[0134] Fig.15 Example pad designs with different start angles according to various embodiments are depicted. This is one of the most important shape variables. A relatively large start angle (OA) is usually desired, such as greater than 180 degrees or at least greater than 90 degrees. A relatively large horizontal offset is also usually required. The horizontal offset can be defined as the horizontal distance (along the longitudinal length of the knife handle) between the start point of the spring and the point where the shoe of the spring, such as the shoe face contacts the locking stud in the locked loaded position, such as Fig. 12A as shown in .

[0135] Recall that in Fig. 12AIn pad design 800, the starting angle is greater than 225 degrees. In pad design 1510, the starting angle is less than the starting angle of pad design 800, but still greater than 180 degrees. In pad design 1520, the starting angle is similar to the starting angle of pad design 1510. In addition, the horizontal offset is greater than the horizontal offset in pad designs 800 and 1510. The starting angle of pad design 1530 is less than the starting angles of pad designs 800, 1510, and 1520, but still greater than 180 degrees.

[0136] At this point, some conclusions can be drawn. First, a good combination of vertical height, arc length, bend radius, and start angle are all additionally beneficial. Second, a spring with otherwise good characteristics may be ruined if one of the variables is unfavorable. Third, the width and thickness of the lever arm material have a strong influence on the spring constant. Fourth, the most important shape variables are total vertical height and total arc length. The next most important shape variables are bend radius and start angle.

[0137] Fig.16 Depicted are example liner designs according to various embodiments. Liner design 1600 has a J-shaped spring 1601 in a liner 1602 and has good X displacement, but also has some Y displacement. Liner design 1600 takes up the least space and is the easiest to manufacture. In addition, the height of the forward region 1603 of the liner cutout 1605 is slightly larger (e.g., up to 10% to 25% larger) than the diameter of the locking stud to guide the forward and backward movement of the locking stud. Spring 1601 is shown in a locked loaded position.

[0138] When comparing the locked load position and the maximum load position of the spring, the X displacement refers to the movement of the shoe in the x-direction or horizontal direction, and the Y displacement refers to the movement of the shoe in the y-direction or vertical direction. Horizontal movement is desirable because it allows the locking stud to move rearward, while vertical movement may be less desirable because the locking stud may move away from the top gasket wall and rebound, as previously described.

[0139] The pad design 1610 has good X displacement and essentially no Y displacement. The pad design 1610 takes up more space in the X direction than the pad design 1600. The spring is shown in a locked load position 1611 and a maximum load position 1612. Advantageously, the displacement of the shoe 1611a between the two positions is essentially limited to the horizontal direction, which is the direction of movement of the locking stud. In addition, there is no additional friction. However, this design requires a larger pad body and cutout.

[0140] Compared to pad designs 1600 and 1610, pad design 1620 has maximum X displacement and substantially no Y displacement, although it may be more difficult to manufacture and takes up more space. The spring is shown in a locked load position 1621 and a maximum load position 1622. The spring has moved out of the plane of the cutout in the maximum load position. The spring includes an additional bend 1623. The displacement of the shoe member 1621a between the two positions is again substantially limited to the horizontal direction.

[0141] Pad design 1600 may be preferred over other designs due to its compact shape.

[0142] Generally speaking, along with the increase of spring height and the reduction of starting point in liner, the shoe of spring advantageously has greater horizontal displacement and less vertical displacement.In this case, spring tends to make locking stud remain against the top wall of liner, to prevent rattling.

[0143] Furthermore, when the horizontal range of the spring is relatively large (e.g., the horizontal range of the spring in pad design 1610 or 1620 is relatively large compared to pad design 1600), the shoe member tends to move rightward and upward when transitioning from the locked load position to the maximum load position. Additionally, the horizontal displacement of the shoe member is relatively large and the spring constant is relatively low.

[0144] Similarly, when the horizontal range of the spring is relatively small (e.g., the horizontal range of the spring in pad design 1600 is relatively small compared to pad designs 1610 and 1620), the shoe member tends to move rightward and downward when transitioning from the locked load position to the maximum load position. In addition, the horizontal displacement of the shoe member is relatively small and the spring constant is relatively large.

[0145] Fig.17 Depicted are example pad designs of varying efficiency according to various embodiments. This relates to lessons learned regarding stress balance. In general, increased x-displacement and lower spring constants can be achieved without increasing stress by distributing the stress over a greater number of bends and a greater distance in the spring. Pad designs 1700 and 1710 represent relatively low efficiencies because the number of bends and the length of the spring are relatively low. Pad designs 1720 and 1730 represent moderate efficiencies because the number of bends and the length of the spring are intermediate, between relatively low and relatively high. Pad designs 1740 and 1750 represent relatively high efficiencies because the number of bends and the length of the spring are relatively high. However, spring effectiveness also depends on the starting point and the total horizontal width of the spring.

[0146] Some non-limiting examples of various implementations are given below.

[0147] Example 1 includes a knife comprising: a blade; and a handle attached to the blade, wherein the blade is capable of rotating about a pivot point in the handle, and the handle includes: a slot in which a locking stud will move in a forward and rearward direction; a liner; and a curved elongated spring, wherein the curved elongated spring extends from a starting point of the liner to a free end and includes a shoe-shaped member at the free end that is used to bias the locking stud in a forward direction.

[0148] Example 2 includes the tool of Example 1, wherein the curved elongated spring is vertically oriented, the height of the curved elongated spring being greater than the overall horizontal width.

[0149] Example 3 includes a knife according to Example 1 or 2, wherein the locking stud contacts the tang of the blade, the tang including a flat surface and a rounded surface, when the blade is in the open position, the locking stud contacts the flat surface to lock the blade in the open position, and when the blade is switched between the open position and the closed position, the locking stud contacts the rounded surface to allow the blade to switch between the open position and the closed position.

[0150] Example 4 includes a tool according to any of Examples 1 to 3, wherein the curved elongated spring has a spring constant of 3 lbs / in to 15 lbs / in (525 N / m to 2626 N / m), 2 lbs / in to 25 lbs / in (350 N / m to 4378 N / m), or 5 lbs / in to 20 lbs / in (875 N / m to 3502 N / m).

[0151] Example 5 includes the tool of any of Examples 1 to 4, wherein a ratio of a vertical height of the curved elongated spring to a vertical height of the pad is at least 0.4 or 0.5.

[0152] Example 6 includes the tool of any of Examples 1 to 5, wherein a ratio of an arc length of the curved elongated spring to a vertical height of the pad is at least 0.5 or 0.6.

[0153] Example 7 includes the tool of any of Examples 1 to 6, wherein the curved elongated spring is integrally formed as one piece with the liner.

[0154] Example 8 includes the tool of any of Examples 1 to 7, wherein the curved elongated spring is a separate piece attached to the liner.

[0155] Example 9 includes the tool of any of Examples 1 to 8, wherein the starting point is located in front of the shoe member and below the shoe member.

[0156] Example 10 includes the knife of any of Examples 1 to 9, wherein the shoe member has a flat surface for engaging the locking stud.

[0157] Example 11 includes the knife of any of Examples 1 to 10, wherein the rear side of the shoe member includes a protruding stop.

[0158] Example 12 includes a knife according to any one of Examples 1 to 11, wherein the liner is a first liner of the knife, the knife further comprising a second liner, the first liner and the second liner being located on opposite sides of the tang of the blade, and the second liner comprising a curved elongated spring for biasing the locking stud in a forward direction.

[0159] Example 13 includes the tool of any of Examples 1 to 12, wherein the curved elongated spring is J-shaped.

[0160] Example 14 includes a liner for a knife, the liner comprising: a body, the body comprising a metal sheet; and a curved elongated spring, the curved elongated spring extending in a cutout area of ​​the body, starting from a starting point and extending to a shoe-shaped piece at a free end of the elongated spring.

[0161] Example 15 includes the liner of Example 14, wherein the shoe member biases a locking stud of the knife in a forward direction of the knife.

[0162] Example 16 includes the gasket of Example 14 or 15, wherein the curved elongated spring is formed as one piece with the body from sheet metal.

[0163] Example 17 includes the cushion of any of Examples 14 to 16, wherein the curved elongated spring is a separate piece attached to the body.

[0164] Example 18 includes a cushion according to any of Examples 14 to 17, wherein the curved elongated spring has a minimum bend radius in the range of about 2 mm (0.08 inches) to about 10 mm (0.39 inches).

[0165] Example 19 includes a cushion according to any of Examples 14 to 18, wherein the curved elongated spring is J-shaped.

[0166] Example 20 includes the liner of any of Examples 14 to 19, wherein the starting point is located in front of the shoe member and below the shoe member.

[0167] Example 21 includes a pad according to any of Examples 14 to 20, wherein the curved elongated spring has a spring constant of approximately 3 lbs / in to 15 lbs / in (525 N / m to 2626 N / m), 2 lbs / in to 25 lbs / in (350 N / m to 4378 N / m), or 5 lbs / in to 20 lbs / in (875 N / m to 3502 N / m).

[0168] Example 22 includes a cushion according to any one of Examples 14 to 21, wherein the ratio of the vertical height of the curved elongated spring to the vertical height of the cushion is at least 0.4 or 0.5, and the ratio of the arc length of the curved elongated spring to the vertical height of the cushion is at least 0.5 or 0.6.

[0169] Example 23 includes the cushion of any of Examples 14 to 22, wherein the curved elongated spring is vertically oriented, the height of the curved elongated spring being greater than the overall horizontal width.

[0170] Example 24 includes a knife comprising: a blade; and a handle attached to the blade, wherein the blade is capable of rotating about a pivot point in the handle, and the handle comprises: a first pad and a second pad spaced apart from each other, wherein each corresponding pad comprises a slot for a locking stud, each corresponding pad comprises a curved elongated spring, and for each corresponding pad, the curved elongated spring extends from a starting point of the pad to a free end, and comprises a shoe-shaped member at the free end, the shoe-shaped member being used to bias the locking stud in a forward direction to lock the blade in an open position.

[0171] Example 25 includes the tool of Example 24, wherein, for each respective pad, the curved elongated spring is vertically oriented, the curved elongated spring having a height greater than an overall horizontal width.

[0172] Example 26 includes the tool of example 24 or 25, wherein the curved elongated spring is integrally formed as one piece with the liner.

[0173] Example 27 includes the tool of any of Examples 24 to 26, wherein the curved elongated spring is a separate piece attached to the liner.

[0174] Example 28 includes the tool of any of Examples 24 to 27, wherein the starting point is located in front of the shoe member and below the shoe member.

[0175] Example 29 includes the tool of any of Examples 24 to 28, wherein the shoe has a flat surface for engaging the locking stud.

[0176] Example 30 includes the tool of any of Examples 24 to 29, wherein the curved elongated spring is J-shaped.

[0177] Although certain embodiments have been illustrated and described herein, it will be appreciated by those skilled in the art that various alternative and / or equivalent embodiments or implementations calculated to achieve the same purpose may be substituted for the embodiments shown and described without departing from the scope. It will be readily appreciated by those skilled in the art that embodiments may be implemented in a variety of ways.

[0178] This application is intended to cover any adaptations or variations of the embodiments discussed herein.It is manifestly intended, therefore, that the embodiments be limited only by the claims and their equivalents.

Claims

1. A cutting tool, comprising: blade; as well as a handle attached to the blade, wherein the blade is rotatable about a pivot point in the handle, and the handle comprises: a slot in which the locking stud will move in a forward direction and a rearward direction; Padding; and A curved elongated spring, wherein the curved elongated spring extends from a starting point of the pad to a free end, and includes a shoe-shaped member at the free end, the shoe-shaped member being used to bias the locking stud in the forward direction.

2. The tool according to claim 1, wherein: The curved elongated spring is vertically oriented, with the height of the curved elongated spring being greater than the overall horizontal width.

3. The tool according to claim 1 or 2, wherein: The locking stud contacts the tang of the blade, and the tang includes a flat surface and a rounded surface. When the blade is in the open position, the locking stud contacts the flat surface to lock the blade in the open position. When the blade is switched between the open position and the closed position, the locking stud contacts the rounded surface to allow the blade to switch between the open position and the closed position.

4. The tool according to any one of claims 1 to 3, wherein: The curved elongated spring has a spring constant of 3 lbs / in to 15 lbs / in (525 N / m to 2626 N / m), 2 lbs / in to 25 lbs / in (350 N / m to 4378 N / m), or 5 lbs / in to 20 lbs / in (875 N / m to 3502 N / m).

5. The tool according to any one of claims 1 to 4, wherein: The ratio of the vertical height of the curved elongated spring to the vertical height of the pad is at least 0.4 or 0.

5.

6. The tool according to any one of claims 1 to 5, wherein: The ratio of the arc length of the curved elongated spring to the vertical height of the pad is at least 0.5 or 0.

6.

7. The tool according to any one of claims 1 to 6, wherein: The curved elongated spring is integrally formed as one piece with the gasket.

8. The tool according to any one of claims 1 to 7, wherein: The curved elongated spring is a separate piece attached to the pad.

9. The tool according to any one of claims 1 to 8, wherein: The starting point is located in front of the shoe member and below the shoe member.

10. The tool according to any one of claims 1 to 9, wherein The shoe member has a flat surface for engaging the locking stud.

11. The tool according to any one of claims 1 to 10, wherein The rear side of the shoe member includes a protruding stopper.

12. The tool according to any one of claims 1 to 11, wherein The liner is a first liner of the knife, the knife also includes a second liner, the first liner and the second liner are located on opposite sides of the tang of the blade, and the second liner includes a curved elongated spring for biasing the locking stud in the forward direction.

13. The tool according to any one of claims 1 to 12, wherein: The curved elongated spring is J-shaped.

14. A liner for a knife, the liner comprising: a body, the body comprising a metal sheet; and A curved elongated spring extending in the cut-out region of the body starts from a starting point and extends to a shoe at the free end of the elongated spring.

15. The pad according to claim 14, wherein The shoe member is used to bias the locking stud of the knife in a forward direction of the knife.

16. A pad according to claim 14 or 15, wherein: The curved elongated spring is formed in one piece with the body from the metal sheet.

17. A pad according to any one of claims 14 to 16, wherein The curved elongated spring is a separate piece attached to the body.

18. A pad according to any one of claims 14 to 17, wherein The curved elongated spring has a minimum bend radius in the range of about 2 mm (0.08 inches) to about 10 mm (0.39 inches).

19. A pad according to any one of claims 14 to 18, wherein The curved elongated spring is J-shaped.

20. A pad according to any one of claims 14 to 19, wherein The starting point is located in front of the shoe member and below the shoe member.

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