Vertically oriented curved liner spring for knife handles

Abstract

The liner for the folding knife includes a curved and elongated spring that biases the blade of the knife to an open position or a closed position. The spring can extend in an arc from a starting point to a free end within a notch region of the liner body. The spring may be J-shaped in one approach. The spring may be integrally formed with the liner or formed as a separate piece attached to the liner. The free end can include a shoe that contacts a lock stud of the knife handle. The starting point can be below and in front of the shoe. The spring biases the lock stud forward to lock the blade in the open position. To close the blade, the user moves the lock stud rearward against the spring force of the spring, allowing the blade to rotate to the closed position.

Description

Background Art

[0001] [Cross - reference to Related Applications]

[0002]

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 393,099, filed Jul. 28, 2022, which is incorporated herein by reference. [Technical Field]

[0003]

[0002] This disclosure relates to the field of knives, and more particularly to a liner for a knife, the liner having an integral spring. [Background]

[0004]

[0003] Knives are available in a variety of designs for various purposes. Generally, a knife can be composed of either a fixed blade or a folding blade. Folding - blade knives are more convenient for many applications due to their more compact size. To improve safety and convenience, some folding - blade knives employ a spring mechanism that biases the blade to an open position or a closed position. A locking mechanism can also be provided to lock the blade in the open position. However, existing spring mechanisms have relatively low wear resistance, occupy additional space, and are prone to maintenance problems.

Brief Description of the Drawings

[0005]

[0004] Embodiments of the present disclosure will be more fully understood from the following detailed description given herein and from the accompanying drawings of various embodiments of the present disclosure, but should not be construed as limiting the present disclosure to specific embodiments, which are for purposes of illustration and understanding only. [Figure 1] FIG. 1 is a side view of an exemplary knife 100 according to various embodiments. [Figure 2] FIG. 2 is a side view of a portion of the knife of FIG. 1 including a liner 200 according to various embodiments. [Figure 3A]Figure 3A is a partial side view of an embodiment of a knife liner 300, including an integrated, vertically oriented elongated spring 310, according to various embodiments. [Figure 3B] Figure 3B shows the direction of arrow 360 in Figure 3A according to various embodiments. In this figure, two of the liners 300, liners 300a and 300b, are depicted as the rock stud 120 and the hub 103.

[0006] As mentioned above, typically, two liners of the same type are provided within the handle, one on each side of the tongue. [Figure 3C] Figure 3C depicts a perspective view of the liner 300 from Figure 3A, showing the cross-sectional thickness in various embodiments. [Figure 4] Figure 4 is a partial side view of liner 300 in an embodiment similar to liner 370 in Figure 3A, although according to various embodiments, the liner includes an opening 380. [Figure 5] Figure 5 depicts an embodiment of liner design 500 in which the spring 510 is a separate part attached to the liner 540, according to various embodiments. [Figure 6] Figure 6 illustrates a chart showing the range of forces acting on a single elongated spring in less desirable spring designs according to various embodiments. [Figure 7] Figure 7 illustrates a chart showing the range of forces acting on a single elongated spring in a more preferred spring design according to various embodiments. [Figure 8A] Figure 8A depicts a side view of a liner 800 having a stopper 810 with a J-shaped spring 805 according to various embodiments. [Figure 8B] Figure 8B shows a side view of the liner 800 of Figure 8A during manufacturing, with tabs 820 added for stability according to various embodiments. [Figure 9] Figure 9 depicts the liner 800 of Figure 8A with the spring in the locked load position and the maximum load position according to various embodiments. [Figure 10]Figure 10 is a side view of the tang 1000 with the hook of the knife shown in Figure 2, according to various embodiments. [Figure 11] Figure 11 is a side view of the hookless tang 1100 of the knife in Figure 2, according to various embodiments. [Figure 12A] Figure 12A depicts the liner 800 of Figure 8A, exhibiting various features according to various embodiments. [Figure 12B] Figure 12B shows the liner 800 of Figure 8A, exhibiting various features according to various embodiments. [Figure 13A] Figure 13A illustrates plots of spring constant versus total spring vertical height for various liner designs according to various embodiments. [Figure 13B] Figure 13B illustrates the plot of spring constant versus total spring width for various liner designs according to various embodiments. [Figure 13C] Figure 13C illustrates plots of spring constant versus total spring arc length for various liner designs according to various embodiments. [Figure 13D] Figure 13D depicts plots of spring constant versus minimum bending radius for various liner designs according to various embodiments. [Figure 13E] Figure 13E plots the spring constant and the distance from the starting point to the shoe for various liner designs according to various embodiments. [Figure 13F] Figure 13F illustrates the plot of spring constant versus starting angle for various liner designs according to various embodiments. [Figure 13G] Figure 13G illustrates plots of spring constant versus origin horizontal offset for various liner designs according to various embodiments. [Figure 13H] Figure 13H depicts plots of spring constant versus origin vertical offset for various liner designs according to various embodiments. [Figure 13I] Figure 13I plots the ratio of the spring vertical height to the total liner vertical height against the spring constant of the liner in various embodiments. [Figure 13J] Figure 13J depicts a plot of the ratio of arc length to the total vertical height of the liner versus spring constant for the example liner of Figure 13I, according to various embodiments. [Figure 13K] Figure 13K depicts an example table of spring constant and stress values as a function of spring dimensions, according to various embodiments. [Figure 13L] Figure 13L depicts a plot of spring constant as a function of liner thickness and spring vertical height, corresponding to the table of Figure 13K, according to various embodiments. [Figure 13M] Figure 13M depicts a plot of stress as a function of liner thickness and spring vertical height, corresponding to the table of Figure 13K, according to various embodiments. [Figure 14] Figure 14 depicts example liner designs with different minimum bend radii, according to various embodiments. [Figure 15] Figure 15 shows exemplary liner designs with different starting angles, according to various embodiments. [Figure 16] Figure 16 depicts example liner designs according to various embodiments. <\ [Figure 17] Figure 17 depicts example liner designs with varying efficiency, according to various embodiments.

[0007] Detailed Description

[0008]

[0039] In the following detailed description, reference is made to the accompanying drawings which form a part hereof and which show, by way of illustration, exemplary embodiments that are capable of being implemented. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. Accordingly, the following detailed description is not to be taken in a limiting sense, and the scope of the embodiments is defined by the appended claims and their equivalents.

[0009]

[0040] The various operations are described sequentially as a series of separate operations in a manner that may be useful in understanding the embodiments. However, the order of the description should not be interpreted as meaning that these operations are order-dependent.

[0010]

[0041] (Descriptions may use balanced perspective-based descriptions such as top / bottom, back / front, top / bottom. Such descriptions are used solely to facilitate discussion and are not intended to limit the application of the disclosed embodiments.)

[0011]

[0042] The terms “joined” and “connected” are used together with their derivatives. It should be understood that these terms are not intended to be synonyms of each other. Rather, in certain embodiments, “connected” is used to indicate that two or more elements are in direct physical contact with one another. “Joined” may mean that two or more elements are in direct physical contact. However, “joined” may also mean that two or more elements are not in direct contact with one another, but are still cooperating or interacting with one another.

[0012]

[0043] For explanatory purposes, phrases in the form of "A / B" or "A and / or B" mean (A), (B), or (A and B). For explanatory purposes, phrases in the form of "at least one of A, B, and C" mean (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C). For explanatory purposes, phrases in the form of "(A)B" mean (B) or (AB), i.e., A is any element.

[0013]

[0044] In this description, the terms “embodiments” or “multiple embodiments” may be used, and these terms may refer to one or more of the same or different embodiments, respectively. Furthermore, terms such as “equipped with,” “included,” and “having” as used in relation to embodiments are synonymous.

[0014]

[0045] As mentioned at the beginning, various challenges arise when 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") lock spring mounted on both liners of the knife handle to bias a lock bar that moves within a slot when the blade is opened and closed. For example, U.S. Patent No. 9,862,104, issued January 9, 2018, discloses a horseshoe-shaped lock spring mounted on a liner to bias a lock bar. Other approaches include a liner lock spring that extends along the length of the handle, typically 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 with respect to wear resistance, space requirements, and maintenance issues.

[0015]

[0046] The apparatus described herein addresses the above and other issues. In one embodiment, a liner for a folding knife includes a vertically oriented spring as part of one or both liners in the knife handle. The vertically oriented spring may be curved, elongated, for example, a J-shaped spring, but other shapes are also possible. The spring may be formed from the same sheet of metal or other material on which the liner is formed, or the spring may be formed as a separate part attached to the liner and secured to the liner like a friction fit. The spring may have features, as described herein, that provide a good feel to the user when opening and closing the blade, based on factors such as the amount of tension required to open and close the blade. The spring may be configured to bias a lock stud, which moves within a slot in the handle when the blade is opened and closed, and the lock stud contacts the tang of the blade. Thus, the spring biases the blade toward the open and closed positions for safety.

[0016]

[0047] The liner designs described herein are also expected to have a significantly increased lifespan and allow for a significantly greater number of opening and closing cycles for the knife blade compared to previous designs.

[0017]

[0048] Furthermore, the liner design allows for a thinner handle width because the spring is integrated into the liner or attached to the liner in a notched region within the liner's plane. In addition, using a vertical spring allows for a shorter horizontal length of the liner, enabling a variety of handle design options.

[0018]

[0049] The above and other advantages will become clearer from the following explanation.

[0019]

[0050] Figure 1 is a side view of an embodiment of knife 100 according to various embodiments. The knife includes a blade 101 and a handle 102 extending along a longitudinal axis LA. The bolster 105 of the handle includes a pivot point PP or axis from which the blade can rotate and a slot 115 from which a lock stud 120 can move forward or backward. In one approach, the lock stud is forward when the blade is in an open or closed position and temporarily moves backward when the blade is in an intermediate or partially open position. In particular, the lock stud can interact with the tang of the blade to lock the blade in the open position or rotate the blade to the closed position. A spring mechanism can apply force to the tang via the lock stud to help the user open and close the blade.

[0020]

[0051] The forward direction is, for example, the direction towards the front of the knife or blade tip, and is parallel to the longitudinal axis. The backward direction is, for example, the direction opposite to the forward direction, and is towards the back of the knife. Referring to an xy coordinate system, the forward direction is the x direction, and the backward direction is the -x direction. The vertical direction can be the y direction.

[0021]

[0052] The thumb button 130 is engageable by the user's thumb to assist in moving the blade to the open or closed position. The handle includes a number of fasteners 140-143 to secure the opposing sides of the handle together. Fastener 140 also acts as a stop pin.

[0022]

[0053] Folding blade knives can be used for a variety of purposes at home, while cooking, and outdoors. Such knives are sized to fit the hand of an average user, for example, about 4-5 inches (101-127 mm) in length when the blade is closed, or 7-8 inches (178-203 mm) in length when the blade is open.

[0023]

[0054] Figure 2 is a side view of a portion of the knife of Figure 1, including the liner 200, according to various embodiments. Typically, two liners of the same type are provided on 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 attached to the hub 103 so as to pivot about a pivot point PP. The tang includes a top shoulder 211 that abuts against a 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 inclined portion 212 that contacts a lock stud 120 when the blade is in the fully open position. The lock stud prevents the blade from rotating counterclockwise as long as the lock stud is in the forward position within the slot. A spring mechanism (not shown) biases the lock stud to the forward position so that the blade remains securely locked when in the open position.

[0024]

[0055] As depicted by the lock stud 120r, when the user manually moves the lock stud to the rearward position, the tang can rotate freely, moving the blade to the closed position. As the tang rotates counterclockwise, the rounded portion 213 of the tang contacts the lock stud, preventing the lock stud from hindering the blade's rotation. The lock stud is pushed rearward by the rounded portion 213 of the tang, resulting in an increased force on the spring mechanism. The forward position of the lock stud is the locked load position, as the blade is locked in this position. The spring mechanism can maintain the lock stud in the forward locked load position by applying a relatively small force to it. The rearward position of the lock stud is the maximum load position, as the load on the spring mechanism is greatest in this position. CLR refers to the cycle load range, which is the difference between the maximum load and the locked load.

[0025]

[0056] The following definition can be created: "Lock-up load" or "Lock load": The sum of the forces applied to the lock stud by the springs of both liners at the lock load position. This includes preload and wear tolerance. "Maximum Load": The sum of the forces applied to the lock stud by both springs at the maximum load position. This is when the lock stud is at its rearmost position on the knife handle and includes any extra movement of the end. "Cycle Load Range (CLR)": The difference between the maximum load and the lock load, i.e., ([Spring constant]) x ([Stroke]). "Total Stroke Length" or "Stroke": The distance the lock stud travels from the lock load position to the maximum load position.

[0026]

[0057] Figure 3A is a partial side view of an embodiment of a knife liner 300, including an integrated vertical elongated spring 310, according to various embodiments. In one approach, two such liners are provided, one on each side of the knife handle. The liner includes an opening 305 for a stop pin and an opening 335 for a hub. The pivot point PP is also depicted.

[0027]

[0058] In this embodiment, the spring 310 is formed integrally with the liner from a single sheet metal, for example, a curved, elongated spring is formed integrally with the liner body from a single piece. In other embodiments, the spring is formed separately from the liner and attached to the liner during its manufacture, for example, a curved, elongated spring is a separate part attached to the liner body.

[0028]

[0059] In this embodiment, the spring is generally J-shaped, but can have other shapes. The spring can be generally curved. The spring can be oriented vertically, such that its height is greater than its total horizontal width. The spring extends from the joint or origin 355 into the notched region 340 within the body of the liner. This point can be located below and in front of the pivot point. The spring, also called the lever arm, extends in an arc from its origin to a point directly below the pivot point, and then upward to a point above and to the right of the pivot point. Note that in this figure, the front of the knife handle is on the left and the rear is on the right. This arrangement applies similarly to other line drawings in this specification. In this embodiment, the spring is depicted in three positions. Spring 311 represents the punched position where the spring is formed. At this position, the spring is unloaded. The spring includes a shoe 311a with a surface 311b on which a lock stud can be mounted. Spring 312 represents the locked load position, where the spring is under a relatively small load while the lock stud 120 is stationary relative to the shoe surface. Spring 313 represents the maximum load position, where the spring is under its maximum load while the lock stud 120r is stationary relative to the shoe surface.

[0029]

[0060] In this embodiment, the triangular region 350, referred to as the lock-up triangle, is substantially intact in terms of strength. The liner includes an inner portion 300int adjacent to the opening 335 on one side of the notch region and an outer portion 300ext on the opposite side of the notch region. The notch can extend to the outer periphery of the liner and does not need to enclose it. See, for example, Figure 4.

[0030]

[0061] The stopper 320 is a bump within the wall 330 of the notch, which restricts the rearward movement of the spring and shoe. In this embodiment, the bump extends forward toward the knife. All contact between the spring and the liner must be behind the shoe. It is undesirable for the center of the spring to contact the liner. The spring can extend to its outer circumference in the deformed (maximum load) state, but cannot extend in the neutral (locked load) state.

[0031]

[0062] Figure 3B is a diagram in the direction of arrow 360 in Figure 3A, according to various embodiments. This diagram depicts two of the curved, elongated liners 300, a lock stud 120 and a hub 103, as the first liner 300a and the second liner 300b, respectively. As previously mentioned, two liners of the same type can be provided on the handle, one on each side of the tongue. The lock stud and hub extend through the liners and can be slightly longer than the distance sp between the liners. The liners are separated from each other by sp. The lock stud can extend outward from the liner so that the user can operate the lock stud with their thumb when closing the blade. The hub can be fixed to the liner, and the lock stud can protrude beyond the liner and move forward and backward with minimal friction.

[0032]

[0063] Figure 3C depicts a perspective view of the liner 300 of Figure 3A showing the cross-sectional thickness (Th) according to various embodiments. As described above, in one possible approach, the spring can be punched out from the same sheet metal as the liner body, such that the spring and the liner body have the same thickness. The width (w) of the spring is also depicted. Alternatively, the thickness of the spring and the liner body may be different.

[0033]

[0064] Figure 4 is a partial side view of a liner 300 in an embodiment similar to the liner 370 in Figure 3A, although according to various embodiments, the liner includes an opening 380. As mentioned above, the notched region 390 of the liner can extend to the outer circumference of the liner and does not need to be surrounded around the spring. This approach allows for weight reduction and provides space for design modifications. The spring has a bending point 450, which refers to a point on the spring where the bending radius is minimal.

[0034]

[0065] Numerous spring design requirements can be set for various embodiments. For example, regarding stress, the requirement may be that the liner can withstand 100k opening / closing cycles without setting, and can withstand one opening / closing cycle during assembly without setting. "Setting" means that the spring arm is stressed to the point where permanent plastic deformation occurs. An example of liner material is a metal such as heat-treated 410 SS. This refers to alloy 410 (UNS S41000), which is a 12% chromium martensitic stainless steel sheet. However, many other materials are possible. In one approach, the metal is sheet metal. Also, if the spring is formed separately from the liner, the spring can be formed from a different material than the liner.

[0035]

[0066] An example of a yield strength of 186 kilopounds / inch square (ksi) (1,282 mPa) was used as the limit in finite element analysis studies of a device using 410SS metal. The ultimate strength of 216 ksi (1,489 mPa) was also used.

[0036]

[0067] Design requirements for another embodiment include displacement / total stroke length. For example, the total stroke distance of the lock stud, which is the tang displacement plus a minimum clearance of 0.015 inches. An embodiment of stroke length is 0.1028 inches for lock engagement (0.0678 inch stroke + 0.020 inch diameter increase for suckback + 0.015 inch minimum bonus clearance). Suckback refers to the action of the spring that biases the blade toward the closed position. Note that other axial lock designs have had a total stroke length of approximately 0.200 inches (longer stroke, more over-stroke / bonus clearance). To obtain optimal suckback, the stroke length needs to be longer.

[0037]

[0068] Regarding spring rate, also known as spring constant, a lower value is preferable to create a similar feel at "locked load" and "maximum load." Common target embodiments are 10 pounds / inch (1751 N / m) total, or 5 pounds / inch (875 N / m) per liner. The spring constant is usually expressed as the sum when two liners are used in the knife handle. The spring constants in this document follow this convention.

[0038]

[0069] Regarding the design requirements for the forces, one approach is to start with a target lock load of approximately 1.0 lb (44.4 N). This can be increased as needed. In one approach, the CLR (depending on the spring design and total stroke length) is ideally less than 1.0 lb (44.4 N). Once the lock load target and CLR are set, the maximum load can be freely adjusted within an acceptable stress range. Typically, under a locked load condition, the force is at least 0.15 lb (0.67 N) per liner (totaling 0.3 lb or 1.33 N).

[0039]

[0070] Other desirable design requirements include corrosion resistance, ease of assembly, reasonable manufacturing / processing costs, the ability of the lock studs to move along the slot without excessive friction, and ensuring that the lock studs do not fall below the top edge of the slot or liner opening. That is, the lock studs should be held against the top wall / edge of the liner notch area by a spring shoe.

[0040]

[0071] Figure 5 depicts a liner design 500 in an embodiment in which the spring 510 is a separate part attached to the liner 540, according to various embodiments. Instead of integrating the spring and liner as a single part, the spring can be punched out from a separate sheet metal from the liner. The spring is then fitted and installed securely into the liner, for example, by friction fitting or pressure fitting, or otherwise attached to the liner. This can offer advantages such as allowing the spring to be formed from a different material and / or have a different thickness than the liner. Different materials and / or thicknesses can be designed to optimize the characteristics of the spring with respect to spring constant and durability, etc. Also, it is simpler to punch out the spring and liner separately.

[0041]

[0072] Potentially, the springs are replaceable after the knife is manufactured, either for repair or to allow the user to customize the knife's characteristics. For example, the user might want to have a greater or less force when opening and closing the blade by installing springs with larger or smaller spring constants, respectively. In this design, the springs may be replaceable.

[0042]

[0073] In this embodiment, the spring is long and curved and has three bending points 550, 551, and 552.

[0043]

[0074] The spring 510 includes an end portion 510a that fits into a correspondingly shaped opening 541 in the liner at the spring's origin 555. The spring also includes a free portion 510b extending from the origin to the free end. At the free end, the shoe 520 includes a groove or recess 521 on its surface for holding the lock stud 120. The groove faces upward so that the spring tends to hold the lock stud against the top wall 542 of the liner, preventing a clicking sound when the lock stud falls away from the top wall and then snaps back against it. A stopper 530 is also depicted to restrict the rearward movement of the spring at the maximum load position. The spring is shown in the locked load position.

[0044]

[0075] Figure 6 illustrates a chart showing the range of forces acting on a single elongated spring in a less desirable spring design according to various embodiments. Such a spring design has a relatively large CLR and offers few options for achieving the desired force biasing the lock stud, requiring operation at or near the spring's maximum stress capacity. The chart shows that the lock load (LL) force (left bar extending from 0–0.9 lb or 0–4.0 N) is approximately 0.9 lb (4.0 N), the CLR force is approximately 1.7 lb or 7.5 N (center bar extending from 0.9–2.6 lb or 4.0–11.5 N), and the remaining maximum stress (MS) margin is only approximately 0.1 lb or 0.44 N (right bar extending from 2.6–2.7 lb or 11.5–12.0 N).

[0045]

[0076] Figure 7 depicts a chart showing the range of forces acting on a single elongated spring in a more preferred spring design according to various embodiments. A good spring design has a relatively small CLR and offers many options for achieving the desired force to bias the lock stud, avoiding the need to operate at or near the spring's maximum stress capacity. The chart shows that the lock load force (left bar extending from 0–1.0 lb or 0–4.4 N) is approximately 1.0 lb (4.4 N), the CLR force is approximately 0.8 lb or 3.5 N (center bar extending from 1.0–1.8 lb or 4.4–8.0 N), and the remaining maximum stress margin is approximately 0.5 lb or 2.2 N (right bar extending from 1.8–2.3 lb or 8.0–10.2 N). Therefore, the spring force on the lock stud is 1.0 lb (4.4 N) at the lock load position of the spring and 1.8 lb (8.0 N) at the maximum load position of the spring. The spring can be designed to set the lock load force or the maximum load force to a desired level. The maximum stress margin represents the optional load range.

[0046]

[0077] The design and manufacturing process can proceed as follows: First, set the target lock load to approximately 1.00 lb (4.4 N). Second, aim to minimize the CLR by minimizing the cross-sectional area of ​​the lever arm, maximizing the vertical length and total arc length of the lever arm, and minimizing strokes 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. In some cases, the target lock load may need to be increased for heavier blades to achieve the desired suck-back to the closed position.

[0047]

[0078] Figure 8A depicts a side view of a liner 800 having a stopper 810 with a J-shaped spring 805, according to various embodiments. As mentioned earlier, it is useful to have a stopper that limits the maximum deflection of the spring. The stopper allows the maximum displacement but not beyond it, so that it does not take a set position during assembly, and for example, the spring arm is not subjected to stress to the point where permanent plastic deformation occurs, and instead the spring arm can return to its original shape. In this embodiment, the stopper is on the back side of the shoe. In other embodiments, the stopper is part of the liner, such as the stopper 320 in Figure 3A.

[0048]

[0079] Figure 8B depicts a side view of the liner 800 of Figure 8A during manufacturing, where tabs 820 are added for stabilization according to various embodiments. The tabs can be punched into the sheet metal with springs. The tabs are fixed with springs during manufacturing and then removed, for example, by cutting.

[0049]

[0080] Figure 9 depicts the liner 800 of Figure 8A with the spring in the locked load position and the maximum load position according to various embodiments. The stopper 810 is located on the back side of the J-shaped spring 805 (towards the rear end of the handle) rather than on the rear wall of the liner. The locked load position is represented by the spring 805 and the lock stud 120, and the maximum load position is represented by the spring 805a and the lock stud 120r.

[0050]

[0081] The flat shoe surfaces 910 and 930, compared to the concave shoe surface in Figure 3A, help to hold the rock stud against the top wall of the slot. With the flat shoe surface, as the rock stud moves backward, the rock stud curls up the shoe surface. This holds the rock stud against the top surface of the slot. In addition, in this design, the motion of the rock stud is greater for the amount of spring deflection, resulting in a "softer" spring constant without adding stress to the spring.

[0051]

[0082] Furthermore, the liner is molded with material 920 at the upper right corner of the opening to prevent the lock stud from slipping through the shoe.

[0052]

[0083] In contrast, the design in Figure 3A could produce a clicking sound because the lock stud is located on the concave side of the shoe, allowing it to be pulled away from the upper wall of the liner when the shoe is pulled back, and then spring back and hit the wall.

[0053]

[0084] Figure 10 is a side view of the tang 1000 with a hook for the knife of Figure 2, according to various embodiments. In this tang design, the hook 1001 has a tendency to catch or hook the lock stud 120. This contributes to pulling the lock stud away from the top wall of the slot, which may produce an undesirable clicking sound when the knife is in use.

[0054]

[0085] Figure 11 is a side view of the hookless tang 1100 of the knife in Figure 2, according to various embodiments. This is a modified blade tang design that can solve the click problem in Figure 10 by rounding the tip of the hook to provide a rounded area 1101.

[0055]

[0086] Figure 12A depicts the liner 800 of Figure 8A, exhibiting various features according to different embodiments. The radius of the spring, also called the bending radius, varies at different points along the spring. Figure 12A shows different bending radii r1 to r3 at points in three embodiments. The bending radius decreases as the bend becomes sharper and increases as the bending radius becomes gentler. r1 is the radius at the origin of the spring. The spring has a minimum bending radius at some point along its length. In some cases, the minimum bending radius is at or near the bottom of the spring. Stress concentrates at the minimum bending radius, which determines the spring constant and stress drives. Some springs have a relatively constant bending radius over most of their length, while others have one main bending region with a constant radius, and intentionally reduce the bending radius in one region to promote localized bending points. In all these cases, the minimum bending radius remains important.

[0056]

[0087] The spring origin refers to the point on the shoe surface that contacts the lock stud. For example, this is the center of the shoe surface. The shoe is at the free end (FE) of the spring. A stopper (PS) protrudes from the rear side of the shoe. The shoe angle is the angle of the shoe surface relative to the vertical, measured clockwise from the vertical. Horizontal is, for example, the direction parallel to the longitudinal axis (LA) of the knife handle (see Figure 1) extending along the longitudinal direction of the knife handle, and vertical (y-axis) is the direction perpendicular to the horizontal (x-axis) and the longitudinal axis. The origin vertical offset is the vertical distance between the spring origin and the origin of the shoe surface. The origin angle (OA) is the angle of the straight line drawn clockwise in the figure with respect to the perpendicular between the spring origin and the origin of the shoe surface. In this embodiment, the origin angle is approximately 230 degrees, and for example, greater than 225 degrees. In this embodiment, the spring has one bend. In other embodiments, the spring has multiple bends in opposite directions. For example, see liner design 1620 in Figure 16. The starting point horizontal offset is the horizontal distance between the starting point 1201 of the spring and the starting point 1202 of the shoe surface.

[0057]

[0088] Figure 12B depicts the liner 800 of Figure 8A, exhibiting various features according to various embodiments. 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 surface. The total horizontal width of the spring is the horizontal distance between the origin of the spring and the rearmost point (rp). The total arc length (AL) of the spring is the distance along the spring from the origin to the origin of the shoe face. The total spring arc length (AL) is the distance along the spring from the origin to the origin of the shoe surface.

[0058]

[0089] Several observations can be made regarding the optimization of springs and liners. Firstly, thinner and narrower springs have lower spring constants and lower stress at the maximum load position, which is desirable. The spring constant is a strong function of the thickness and width of the lever arm. Reducing the width reduces the stress, but changing the thickness does not affect the stress. One approach is to use the minimum spring thickness and width to optimize the CLR at a low level while reducing stress, 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 untreated sheet material.

[0059]

[0090] Another observation shows that softer (gentler) bending points of a spring result in a smaller CLR for similar stress, while sharper (less gentle) bending points result in a smaller CLR but higher stress. The optimal spring shape depends on the morphological factors of the knife. In some cases, a minimum bending radius in the range of approximately 2 mm (0.08 inches) to approximately 5 mm (0.20 inches) works well. The bending radius can be varied along the spring so that the minimum bending radius is at the sharpest bending point along the arc length of the spring. Therefore, making the bending point sharper increases the stress but lowers the spring constant.

[0060]

[0091] Another observation is that a higher starting point for the spring and a longer arc length contribute to a decrease in the spring constant.

[0061]

[0092] Another observation is that greater vertical height significantly reduces the spring constant. In fact, increasing the vertical height of a spring is the single greatest factor in decreasing the spring constant. The effect of vertical height is greater than the effect of the starting point in decreasing the spring constant. However, increasing the vertical height will make the minimum bending radius too flat (too large), thus increasing the spring constant. See, for example, the liner design in Figure 14.

[0062]

[0093] This section describes the test data for the J-shaped spring.

[0063]

[0094] In Figures 13A-13J, the circled points represent a liner / spring thickness of 0.040 inches (1.016 mm) and a spring width of 0.025 inches (0.635 mm), while the other points represent a liner / spring thickness of 0.050 inches (1.270 mm) and a spring width of 0.030 inches (0.762 mm). The unit of spring constant is pounds per inch or N / m. The unit of length is inches or mm.

[0064]

[0095] Figure 13A depicts plots of spring constant versus total spring vertical height for various liner designs according to various embodiments. The data shows a very strong correlation between the vertical height of the spring and the spring constant. In particular, the spring constant decreases as the vertical height increases.

[0065]

[0096] Outlier point 1300 arises from a flat bending radius and a starting angle close to 180 degrees.

[0066]

[0097] The spring constant ranges from 5–19 lb / in or 3327 N / m, and the total vertical height ranges from 0.400–1.200 in or 10–30 mm.

[0067]

[0098] Figure 13B depicts plots of spring constant versus total spring horizontal width for various liner designs according to various embodiments. There is a slight correlation, but no strong correlation, between horizontal width and spring constant. In particular, the spring constant decreases as the horizontal width increases.

[0068]

[0099] The spring constant ranges from 5–19 lb / in or 875–3327 N / m, and the horizontal width ranges from 0.300–0.750 in or 7.6–19 mm.

[0069]

[0100] Figure 13C depicts plots of spring constant versus total spring arc length for various liner designs according to various embodiments. There is a very strong correlation between arc length and spring constant. In particular, the spring constant decreases as the arc length increases. Outlier point 1310 arises from a short vertical height.

[0070]

[0101] The spring constant ranges from 5 to 19 lb / in or 875 to 3327 N / m, and the total arc length ranges from 0.600 to 2.000 in or 15 to 51 mm.

[0071]

[0102] Figure 13D depicts plots of spring constant versus minimum bending radius for various liner designs according to various embodiments. There is a strong correlation between the minimum bending radius and the spring constant. In particular, the spring constant decreases as the bending radius decreases. Point 1320 shows how the difference between springs with the same minimum bending radius changes with vertical height. Point 1325 has better performance because it has a very high vertical height that exceeds the bending radius on a flat surface.

[0072]

[0103] The spring constant ranges from 5 to 19 lb / in or 875 to 3327 N / m, and the bending radius ranges from 0.000 to 1.000 in or 0 to 25 mm.

[0073]

[0104] Figure 13E plots the spring constant versus the distance from the starting point to the shoe for various liner designs according to different embodiments. There is no correlation, indicating that distance is not a significant variable.

[0074]

[0105] The spring constant ranges from 5–19 lb / in or 875–3327 N / m, and the distance ranges from 0,400–1,200 in or 10–30 mm.

[0106]

[0075]

[0107] Figure 13F depicts plots of spring constant versus origin angle for various liner designs according to various embodiments. There is a correlation between the origin angle and the spring constant. In particular, the spring constant decreases as the origin angle increases. Outliers 1330 and 1335 are due to other important variables being in poor positions; for example, these two points represent the vertical height of a very short spring.

[0076]

[0108] The spring constant ranges from 5–19 lb / in or 875–3327 N / m, and the starting angle ranges from 180–250 degrees.

[0077]

[0109] Figure 13G depicts plots of spring constant versus origin horizontal offset for various liner designs according to various embodiments. There is a slight correlation, but no strong correlation, between the origin horizontal offset and the spring constant. In particular, the spring constant decreases as the origin horizontal offset increases.

[0078]

[0110] The spring constant ranges from 5–19 lb / in or 875–3327 N / m, and the horizontal offset ranges from 0.200–0.700 in or 5–18 mm.

[0079]

[0111] Figure 13H depicts plots of spring constant versus origin vertical offset for various liner designs according to various embodiments. The lack of correlation indicates that the origin vertical offset is not a significant variable.

[0080]

[0112] The spring constant ranges from 5–19 lb / in or 875–3327 N / m, and the vertical offset ranges from 0.100–1.100 in or 3–28 mm.

[0081]

[0113] Figure 13I depicts plots of the ratio of the spring vertical height to the total liner vertical height against the spring constant of the liner in 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, to lower the spring constant, it is appropriate to make the ratio greater than 0.4. It is even better if it exceeds 0.5. There is no upper limit, and the higher the ratio, the better. The total vertical height represents the maximum vertical range of the liner when the vertical direction is perpendicular to the longitudinal axis in one approach.

[0082]

[0114] In the embodiment, the ratio of the vertical height of the curved elongated spring to the vertical height of the liner is at least 0.4 or 0.5.

[0083]

[0115] The spring constant ranges from 5–30 lb / in or 875–5253 N / m, and the ratio ranges from 0.30–0.75.

[0084]

[0116] Figure 13J plots the ratio of arc length to total vertical height of the liner versus the spring constant for the liner of the embodiment in Figure 13I, according to various embodiments. There is a strong correlation between this ratio and the spring constant. In particular, the spring constant decreases as the ratio increases. Generally, a value greater than 0.5 is suitable for lowering the spring constant. It gets even better above 0.6. There is no upper limit, and a higher ratio is better.

[0085]

[0117] In the embodiment, the ratio of the arc length of the curved, elongated spring to the vertical height of the liner is at least 0.5 or 0.6.

[0086]

[0118] The spring constant ranges from 5–30 lb / in or 875–5253 N / m, and the ratio ranges from 0.40–1.20.

[0087]

[0119] Figure 13K depicts an example table of spring constants and stress values ​​according to spring dimensions, according to various embodiments. The data was obtained from springs with vertical heights of 0.53 inches (13 mm), 0.59 inches (15 mm), 1.00 inches (25 mm), and 1.08 inches (27 mm), and is generalized in the table to vertical heights of 0.5 inches (13 mm), 0.7 inches (18 mm), 0.9 inches (23 mm), and 1.1 inches (28 mm).

[0088]

[0120] The first column depicts the spring dimensions in inches (in.) and millimeters, thickness (th) × width (w); the second through fifth columns express the spring constants in lb / in and N / m for different vertical heights; and the sixth through ninth columns express the spring stress in ksi and MPa for a displacement of 0.150 inches (38 mm) for different vertical heights.

[0089]

[0121] The liner thicknesses considered were 0.030 inches (0.762 mm), 0.040 inches (1.016 mm), 0.050 inches (1.270 mm), 0.060 inches (1.524 mm), and 0.070 inches (1.778 mm). These thicknesses refer to the thickness of the finished liner, not the raw material. The spring width was varied along with the liner thickness (0.020–0.040 inches, or 0.508–1.016 mm) as it represents typical manufacturing capability. The ideal spring constant range is, for example, 3.0–15.0 pounds / inch (525–2626 N / m).

[0090]

[0122] In this embodiment, the maximum allowable stress is 186 ksi or 1,282 mPa. A constant total displacement of 0.150” or 3.8 mm was used in the stress calculation (maximum load position including preload).

[0091]

[0123] Generally, the spring constant decreases as the vertical height of the spring increases, and increases as the thickness and width increase. Also, the stress decreases as the vertical height of the spring increases, and increases as the thickness and width increase.

[0092]

[0124] Figure 13L depicts plots of spring constant and vertical spring height as a function of liner thickness, consistent with the table in Figure 13K, according to various embodiments. Plots 1350–1353 represent vertical spring heights of 0.5 inches (13 mm), 0.7 inches (18 mm), 0.9 inches (23 mm), and 1.1 inches (28 mm), respectively. The ideal spring constant range is, for example, approximately 3–15 lbs / inch (525–2626 N / m), approximately 2–25 lbs / inch (350–4378 N / m), or approximately 5–20 lbs / inch (875–3502 N / m). In general, liner thickness affects the spring constant to the same extent as (if not greater than) the vertical spring height. Shorter springs are more susceptible to the effect of liner thickness. All spring heights will have the appropriate spring constant given the appropriate liner thickness. However, considering the theoretically possible range, not all spring thicknesses / widths can be manufactured in a practical manner. The spring width was varied along with the spring thickness, as noted in the table in Figure 13K.

[0093]

[0125] Figure 13M depicts plots of stress as a function of liner thickness and spring vertical height, consistent with the table in Figure 13K, according to various embodiments. Plots 1360–1363 represent spring vertical heights of 0.5 inches (13 mm), 0.7 inches (18 mm), 0.9 inches (23 mm), and 1.1 inches (28 mm), respectively. For example, the ideal stress range is less than 186 ksi or 1,282 mPa. In general, taller springs may fall below the stress limit at any liner thickness. The sensitivity to liner thickness is approximately the same for all spring heights. However, as with the spring constant, not all spring thicknesses / widths can be manufactured in a practical manner, considering the theoretically possible range. The spring width varies depending on the spring thickness.

[0094]

[0126] Figure 14 shows liner designs of embodiments having different minimum bending radii according to various embodiments. As mentioned above, softer (less gentle) bending points of the spring result in smaller CLRs for similar stresses, while sharper (less gentle) bending points of the spring result in smaller CLRs but higher stresses. Liner design 1400 has a minimum bending radius (MBR) of 4 mm (0.16 inches) at bending point 1401, which is within the guideline range of approximately 2 mm (0.08 inches) to approximately 5 mm (0.20 inches). Liner design 1410 has a relatively small or sharp minimum bending radius of 1.6 mm (0.06”) at bending point 1411, which is smaller than the guideline. In this design, excessively high stresses may be generated in the spring.

[0095]

[0127] Furthermore, as mentioned above, greater vertical height significantly reduces the spring constant. However, if the bending radius is too flat, the spring constant can be increased. For example, liner design 1420 has a relatively tall spring arm, but the minimum bending radius is relatively large at bending point 1421 (16 mm or 0.63"), resulting in a favorably relatively low spring constant. Liner design 1430 has a very large minimum bending radius at bending point 1431 (23 mm or 0.90"), and approaches flatness, so the spring constant increases unfavorably.

[0096]

[0128] Liner designs 1440 and 1450 do not have a narrow bending radius, but are still good designs. Liner designs 1440 and 1450 have minimum bending radii of 6.4 mm (0.25 inches) and 7.9 mm (0.31 inches) at bending point 1441 and bending point 1451, respectively. In some cases, a minimum bending radius of approximately 2 mm (0.08 inches) to approximately 8 mm (0.31 inches) can be used. A minimum bending radius of less than approximately 8 mm (0.31 inches), 10 mm, or 12 mm can be used. In some cases, the minimum bending radius is in the range of approximately 2 mm (0.08 inches) to approximately 8 mm (0.31 inches), or approximately 2 mm (0.08 inches) to approximately 10 mm (0.39 inches). These ranges are for folding knives sized to fit the hand of an average user.

[0097]

[0129] For liner designs 1400, 1410, 1420, 1440, and 1450, the spring is shown at the locked load position and the maximum load position. For liner design 1430, the spring is shown at the locked load position.

[0098]

[0130] Figure 15 shows liner designs for embodiments with different origin angles according to various embodiments. This is one of the most important shape variables. Relatively large origin angles (OA), such as greater than 180 degrees or at least greater than 90 degrees, are typically desired. Relatively large horizontal offsets are also typically desired. The horizontal offset may be defined as the horizontal distance (along the longitudinal length of the knife handle) between the origin of the spring and the shoe of the spring, and may be defined, for example, at the point where the shoe surface contacts the lock stud at the lock load position, as noted in Figure 12A.

[0099]

[0131] Note that in liner design 800 in Figure 12A, the starting angle is greater than 225 degrees. In liner design 1510, the starting angle is smaller than that of liner design 800, but still greater than 180 degrees. In liner design 1520, the starting angle is similar to that of liner design 1510. Furthermore, the horizontal offset is greater than the offset in liner designs 800 and 1510. Liner design 1530 has a starting angle that is smaller than that of liner designs 800, 1510, and 1520, but still greater than 180 degrees.

[0100]

[0132] At this point, several conclusions can be drawn. First, a good combination of vertical height, arc length, bending radius, and origin angle is additively good. Second, a spring that has good characteristics at other points may fail if one of the variables is poor. Third, the width and thickness of the lever arm material have a very strong influence on the spring constant. Fourth, the most important shape variables are the total vertical height and total arc length. The next most important shape variables are the bending radius and origin angle.

[0101]

[0133] Figure 16 shows liner designs of embodiments according to various designs. Liner design 1600 has a J-shaped spring 1601 within the liner 1602, which has good X-direction displacement but some Y-direction displacement. It occupies the smallest space and is the easiest to manufacture. In addition, the front region 1603 of the liner notch 1605 has a height that is slightly larger than the diameter of the lock stud (e.g., up to 10-25%) to guide the forward and backward movement of the lock stud. The spring 1601 is shown in the lock load position.

[0102]

[0134] When comparing the spring's locked load position with its maximum load position, the X displacement represents the shoe's movement in the x-direction or horizontal direction, and the Y displacement represents the shoe's movement in the y-direction or vertical direction. Horizontal movement is desirable because it allows the lock stud to move backward, while vertical movement is less desirable because, as mentioned earlier, it allows the lock stud to snap back away from the top liner wall.

[0103]

[0135] Liner design 1610 has good X-displacement and virtually no Y-displacement. It occupies more space in the X-direction than liner design 1600. The spring is shown at the locked load position 1611 and the maximum load position 1612. It is advantageous that the displacement of shoe 1611a between the two positions is substantially limited in the horizontal direction, which is the direction of motion of the lock stud. Furthermore, there is no additional friction. However, this design requires a larger liner body and notches.

[0104]

[0136] Liner design 1620 has the largest X displacement compared to liner designs 1600 and 1610, and essentially has no Y displacement, but is more difficult to manufacture and may occupy more space. The spring is shown at the locked load position 1621 and the maximum load position 1622. The spring moved from the plane of the notch at the maximum load position. The spring includes an additional bend 1623. The displacement of the shoe 1621a between the two positions is, here again, essentially limited to the horizontal direction.

[0105]

[0137] Liner design 1600 is preferred over other designs due to its compact shape.

[0106]

[0138] Generally, as the height of the spring increases and the starting point within the liner decreases, the horizontal displacement of the spring shoe increases, while the vertical displacement decreases, which is advantageous. In this case, the spring tends to hold the lock stud against the top wall of the liner to prevent clicking noises.

[0107]

[0139] In addition, when the horizontal range of the spring is relatively large (as in liner design 1610 or liner design 1620 compared to liner design 1600), the shoe tends to move to the right and upward when transitioning from the locked load position to the maximum load position. Also, the horizontal displacement of the shoe is relatively large and the spring constant is relatively small.

[0108]

[0140] Similarly, when the horizontal range of the spring is relatively small (for example, liner design 1600 compared to liner designs 1610 and 1620), the shoe tends to move to the right and down as it transitions from the locked load position to the maximum load position. Also, the horizontal displacement of the shoe is relatively small and the spring constant is relatively large.

[0109]

[0141] Figure 17 shows liner designs for embodiments where efficiency varies according to various embodiments. This includes lessons learned regarding stress balance. In general, by distributing the stress over more bends and longer distances within the spring, it is possible to increase the x-displacement without increasing the stress and obtain a lower spring constant. Liner designs 1700 and 1710 represent relatively low efficiency because the number of bends and spring length are relatively low. Liner designs 1720 and 1730 represent intermediate efficiency because the number of bends and spring length are between relatively low and relatively high. Liner designs 1740 and 1750 represent relatively high efficiency because the number of bends and spring length are relatively high. However, the effectiveness of the spring also depends on the origin and the total horizontal width of the spring.

[0110]

[0142] Some non-limiting embodiments of various models are shown below.

[0111]

[0143] Embodiment 1 includes a knife comprising a blade and a handle attached to the blade, wherein the blade is rotatable about a pivot point in the handle, the handle comprising a slot for a lock stud to move forward and backward, a liner, and a curved elongated spring, the curved elongated spring extending from the liner at its starting point to a free end, the free end having a shoe for biasing the lock stud forward.

[0112]

[0144] Example 2 includes the knife of Example 1, wherein the curved, elongated spring is oriented vertically and has a height greater than its total horizontal width.

[0113]

[0145] Example 3 includes the knife of Example 1 or Example 2, wherein the lock stud is in contact with the tang of the blade, and the tang has a flat surface to which the lock stud contacts and locks the blade in the open position when the blade is in the open position, and a rounded surface to which the lock stud contacts and allows the blade to move between the open and closed positions when the blade moves between the open and closed positions.

[0114]

[0146] Example 4 includes one of the knives from Examples 1 to 3, and the curved elongated spring has a spring constant of 3 to 15 pounds / inch (525 to 2626 N / m), 2 to 25 pounds / inch (350 to 4378 N / m), or 5 to 20 pounds / inch (875 to 3502 N / m).

[0115]

[0147] Example 5 comprises one of the knives from Examples 1 to 4, wherein the ratio of the vertical height of the curved elongated spring to the vertical height of the liner is at least 0.4 or 0.5.

[0116]

[0148] Example 6 comprises one of the knives from Examples 1 to 5, wherein the ratio of the arc length of the curved elongated spring to the vertical height of the liner is at least 0.5 or 0.6.

[0117]

[0149] Example 7 includes one of the knives from Examples 1 to 6, and the curved, elongated spring is formed integrally with the liner.

[0118]

[0150] Example 8 includes one of the knives from Examples 1 to 7, and the curved, elongated spring is a separate part that is attached to the liner.

[0119]

[0151] Example 9 includes one of the knives from Examples 1 to 8, with the starting point located in front of and below the shoe.

[0120]

[0152] Example 10 includes one of the knives from Examples 1 to 9, and the shoe has a flat surface that engages with a lock stud.

[0121]

[0153] Example 11 includes one of the knives from Examples 1 to 10, and the rear side of the shoe includes a protruding stopper.

[0122]

[0154] Example 12 comprises one of the knives from Examples 1 to 11, wherein Liner is a first liner of the knife, and the knife further comprises a second liner, the first and second liners being on opposite sides of the tang of the blade, and the second liner comprising a curved, elongated spring that biases the lock stud forward.

[0123]

[0155] Example 13 includes one of the knives from Examples 1 to 12, and the curved, elongated spring is J-shaped.

[0124]

[0156] Embodiment 14 includes a liner for a knife and comprises a body made of sheet metal and a curved elongated spring extending into a notched area of ​​the body, starting at the origin and extending to the shoe at the free end of the elongated spring.

[0125]

[0157] Example 15 includes the liner of Example 14, and the shoe biases the lock stud of the knife in the forward direction of the knife.

[0126]

[0158] Example 16 includes the liner of Example 14 or Example 15, and the curved, elongated spring is formed from a sheet metal integral with the body.

[0127]

[0159] Example 17 includes one of the liners from Examples 14 to 16, and the curved, elongated spring is a separate part that is attached to the main body.

[0128]

[0160] Example 18 includes one liner from Examples 14 to 17, and the curved elongated spring has a minimum bending radius in the range of approximately 2 mm (0.08") to approximately 10 mm (0.39").

[0129]

[0161] Example 19 includes one of the liners from Examples 14 to 18, and the curved, elongated spring is J-shaped.

[0130]

[0162] Example 20 includes one of the liners from Examples 14 to 19, with the origin located in front of and below the shoe.

[0131]

[0163] Example 21 includes one liner from Examples 14 to 20, and the curved elongated spring has a spring constant of approximately 3 to 15 pounds / inch (525 to 2626 N / m), 2 to 25 pounds / inch (350 to 4378 N / m), or 5 to 20 pounds / inch (875 to 3502 N / m).

[0132]

[0164] Example 22 includes a liner from either Example 14 or Example 21, wherein the ratio of the vertical height of the curved elongated spring to the vertical height of the liner 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 liner is at least 0.5 or 0.6.

[0133]

[0165] Example 23 includes a liner from any one of Examples 14 to 22, wherein the curved, elongated spring is oriented vertically and has a height greater than its total horizontal width.

[0134]

[0166] Embodiment 24 includes a knife comprising a blade and a handle attached to the blade, wherein the blade is rotatable about a pivot point in the handle, the handle comprising a first liner and a second liner spaced apart from each other, each liner having a slot for a lock stud, each liner having a curved elongated spring, the curved elongated spring extending from the liner at its starting point to a free end, and having a shoe at the free end to bias the lock stud forward and lock the blade in the open position, the first liner and the second liner.

[0135]

[0167] Example 25 includes the knife of Example 24, wherein, for each liner, the curved, elongated spring is oriented vertically and has a height greater than the total horizontal width.

[0136]

[0168] Example 26 includes the knife of Example 24 or Example 25, and the curved, elongated spring is formed integrally with the liner.

[0137]

[0169] Example 27 includes one of the knives from Examples 24 to 26, and the curved, elongated spring is a separate part attached to the liner.

[0138]

[0170] Example 28 includes one of the knives from Examples 24 to 27, with the starting point located in front of and below the shoe.

[0139]

[0171] Example 29 includes one of the knives from Examples 24 to 28, and the shoe has a flat surface that engages with the lock stud.

[0140]

[0172] Example 30 includes one of the knives from Examples 24 to 29, and the curved, elongated spring is J-shaped.

[0141]

[0173] While specific embodiments have been illustrated and described herein, it will be understood by those skilled in the art that a wide variety of alternative and / or equivalent embodiments or implementations calculated to achieve the same objectives can be used in place of the illustrated and described embodiments without departing from the scope. Those skilled in the art will readily understand that embodiments can be implemented in a very wide range of ways.

[0142]

[0174] This application is intended to cover any adaptation or modification of the embodiments discussed herein. Therefore, the embodiments are expressly intended to be limited only by the claims and their equivalents.

Claims

1. A knife comprising a blade and a handle, The handle is attached to the blade, and the blade is rotatable about a pivot point within the handle, and the handle is A slot in which the rock stud moves in the front-to-back direction, Raina and, A curved, elongated spring, Equipped with, The curved, elongated spring extends from the liner at its starting point to its free end, and the free end is equipped with a shoe that biases the lock stud in the forward direction. The curved, elongated spring is formed integrally with the liner, forming a knife.

2. The knife according to claim 1, wherein the curved, elongated spring is oriented vertically and has a height greater than the overall horizontal width.

3. The knife according to claim 1 or 2, wherein the lock stud is in contact with the tang of the blade, and the tang has a flat surface that the lock stud contacts to lock the blade in the open position when the blade is in the open position, and a rounded surface that the lock stud contacts to allow the blade to move between the open position and the closed position when the blade moves between the open position and the closed position.

4. The knife according to claim 3, wherein the curved, elongated spring has a spring constant of 3 to 15 pounds / inch (525 to 2626 N / m), 2 to 25 pounds / inch (350 to 4378 N / m), or 5 to 20 pounds / inch (875 to 3502 N / m).

5. The knife according to claim 4, wherein the ratio of the vertical height of the curved elongated spring to the vertical height of the liner is at least 0.4 or 0.

5.

6. The knife according to claim 5, wherein the ratio of the arc length of the curved elongated spring to the vertical height of the liner is at least 0.5 or 0.

6.

7. The knife according to claim 6, wherein the curved, elongated spring is a separate part attached to the liner.

8. The knife according to claim 7, wherein the starting point is located in front of the shoe and below the shoe.

9. The knife according to claim 8, wherein the shoe has a flat surface that engages with the lock stud.

10. The knife according to claim 9, wherein the rear side of the shoe is provided with a protruding stopper.

11. The knife according to claim 10, wherein the liner is a first liner of the knife, and the knife further comprises a second liner, the first liner and the second liner are located on opposing sides of the tang of the blade, and the second liner comprises a curved, elongated spring that biases the lock stud forward.

12. The knife according to claim 11, wherein the curved, elongated spring is J-shaped.

13. In knife liners, A main body with sheet metal, A curved, elongated spring extending within the notched region of the main body, The elongated spring is provided, and the elongated spring starts at the origin and extends to the shoe at the free end of the elongated spring, The curved, elongated spring is a liner formed from the sheet metal that is integral with the main body.

14. The liner according to claim 13, wherein the shoe biases the lock stud of the knife in the forward direction of the knife.

15. The liner according to claim 14, wherein the curved, elongated spring is a separate component attached to the main body.

16. The liner according to claim 15, wherein the curved, elongated spring has a minimum bending radius in the range of about 2 mm (0.08") to about 10 mm (0.39").

17. The liner according to claim 16, wherein the curved, elongated spring is J-shaped.

18. The liner according to claim 17, wherein the starting point is located in front of the shoe and below the shoe.

Images