High leverage locking pliers

Abstract

A high leverage locking pliers includes a four-bar linkage system adapted to amplify the force applied by a user to an object clamped between the jaws of the pliers. The pliers include a first handle and a second handle, a first jaw and a second jaw, and a center link rotatably or pivotally coupled to the first handle and the second handle. The center link is rotatably or pivotally coupled to the second handle at a first link pivot, the second jaw is rotatably or pivotally coupled to the second handle at a second jaw pivot, and the first link pivot may be a first distance L1 from the second jaw pivot. The second jaw is rotatably or pivotally coupled to the first handle at the first jaw pivot, and the first jaw pivot is a second distance L2 from the second jaw pivot. In one embodiment, the first distance L1 is about 34% to about 70% of the second distance L2.

Description

Technical Field

[0001] The present invention relates generally to locking pliers and, more particularly, to locking pliers adapted to apply a clamping force to an object. Background Art

[0002] Locking pliers are an adjustable hand-held tool that is typically used to clamp a workpiece when other clamping methods fail, such as on round fasteners, studs, or round shafts. The pliers typically include jaws that are adjustable by a threaded screw mechanism to increase or decrease the gap between the jaws based on the size of the workpiece or material being clamped by the locking pliers. For example, locking pliers may include a screw mechanism on the upper handle of the pliers that, when rotated, pushes a center link connected to one of the jaws to raise or lower the jaw relative to the other jaw.

[0003] Locking pliers can also be locked by moving the lower handle toward the upper handle until it "locks," for example, due to interaction between a release lever adjacent the lower handle and a center link connecting the upper handle to the lower handle. To release the locking feature, the release lever can be lifted away from the lower handle to pry the lower handle off the center link.

[0004] However, it is often difficult for the user to apply enough force to the handles of the pliers to lock the pliers and clamp the jaws of the pliers on the workpiece. In addition, in some cases, the user may not be able to apply enough force to the handles to generate the desired jaw clamping force. The insufficient clamping force makes the pliers unable to effectively clamp on the workpiece, and when the user attempts to manipulate the pliers, the jaws of the pliers may slip from the workpiece. Summary of the invention

[0005] The present invention broadly relates to high leverage locking pliers. The pliers include a four-bar linkage system adapted to amplify the force applied by a user to an object clamped between the jaws of the pliers. The linkage system also includes an over-center lock adapted to maintain or lock the jaws closed without additional force from the user. For example, the pliers may include a first handle and a second handle, a first jaw and a second jaw, and a center link rotatably or pivotally coupled to the first handle and the second handle.

[0006] The center link is pivotally coupled to the second handle at a first link pivot, the second jaw is pivotally coupled to the second handle at a second jaw pivot, and the first link pivot may be a first distance L1 from the second jaw pivot. Additionally, the second jaw is pivotally coupled to the first handle at the first jaw pivot, and the first jaw pivot is disposed a second distance L2 from the second jaw pivot. In this embodiment, the first distance L1 is about 34% to about 70% of the second distance L2, and preferably about 43.5% of the second distance L2. This results in an increased clamping force for all jaw types commonly found on locking pliers, while the locking pliers require less user force (e.g., the clamping force is approximately 25 times the user force).

[0007] In one embodiment, the present invention is broadly directed to a tool having first and second handles and first and second jaws. The second jaw is coupled to the first handle at a first jaw pivot and to the second handle at a second jaw pivot. A central link is coupled to the first handle at a slidable pivot and to the second handle at a link pivot. A first distance between the second jaw pivot and the link pivot is about 34% to about 70% of a second distance between the second jaw pivot and the first jaw pivot.

[0008] In another embodiment, the present invention generally relates to a tool having first and second handles and a jaw coupled to the first handle at a first jaw pivot and to the second handle at a second jaw pivot. A central link is coupled to the first handle at a slidable pivot and to the second handle at a link pivot. A first distance between the second jaw pivot and the link pivot is about 34% to about 70% of a second distance between the second jaw pivot and the first jaw pivot. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] To facilitate understanding of the subject matter sought to be protected, embodiments thereof are shown in the accompanying drawings, and by inspection of these drawings, when considered in conjunction with the following description, the subject matter sought to be protected, its construction and operation, and its many advantages should be readily understood and appreciated.

[0010] Figure 1 is a side view of an example pliers according to an embodiment of the present invention.

[0011] Figure 2 is a side view of one handle and jaw of an exemplary pair of pliers according to an embodiment of the present invention.

[0012] Figure 3 is a side view of one handle and jaw of an exemplary pair of pliers according to an embodiment of the present invention. DETAILED DESCRIPTION

[0013] Although the present invention may be implemented in many different forms, preferred embodiments of the present invention are shown in the drawings and will be described in detail herein, with the understanding that the present disclosure is to be considered as an example of the principles of the present invention, rather than intended to limit the broad aspects of the present invention to the embodiments shown. As used herein, the term "present invention" is not intended to limit the scope of the claimed invention, but is a term used to discuss exemplary embodiments of the present invention for explanation purposes only.

[0014] The present invention broadly relates to high leverage locking pliers. The pliers include a four-bar linkage system adapted to amplify the force applied by a user to an object clamped between the jaws of the pliers. The linkage system also includes an over-center lock adapted to hold or maintain the jaws closed without additional force from the user. For example, the pliers may include a first handle and a second handle, a first jaw and a second jaw, and a center link pivotally coupled to the first handle and the second handle. The center link is pivotally coupled to the second handle at a first link pivot, the second jaw rotatably or pivotally coupled to the second handle at a second jaw pivot, and the first link pivot may be a first distance L1 from the second jaw pivot. Additionally, the second jaw is pivotally coupled to the first handle at the first jaw pivot, and the first jaw pivot is disposed a second distance L2 from the second jaw pivot. In this embodiment, the first distance L1 is about 34% to about 70% of the second distance L2, preferably about 43.5% of the second distance L2. This results in increased clamping force for all jaw types commonly found on locking pliers, while requiring less user force to lock or clamp the pliers.

[0015] like Figure 1 As shown, a tool 100 such as locking pliers includes a first handle 102 and a second handle 104 pivotally coupled to each other. A first jaw 106 and a second jaw 108 are coupled to the first handle 102 and the second handle 104, respectively. As shown, each of the first jaw 106 and the second jaw 108 may include teeth 110 or knurling adapted to better grip or "bite" a workpiece or other object disposed between the jaws. However, each of the first jaw 106 and the second jaw 108 may be other types of jaws and include other features. For example, but not limited to, the first jaw 106 and the second jaw 108 may be generally flat clamping jaws, edge cutting jaws, needle-nosed pliers, curved jaws, etc.

[0016] The first and second handles 102, 104 and the first and second jaws 106, 108 are connected together at different pivot points to facilitate operation of the tool 100. For example, the second jaw 108 may be coupled to the first handle 102 at a first jaw pivot 112 and may be coupled to the second handle 104 at a second jaw pivot 114. The second jaw 108 may also be coupled to the first handle 102 via an elastic member that pulls the first and second handles 102, 104 open or closed depending on the position of the first and second handles 102, 104. In one embodiment, the first handle 102 is fixedly coupled to the first jaw 106 and the second handle 104 is rotatably or pivotally coupled to the second jaw 108.

[0017] The tool 100 also includes a central link 116 that is pivotally coupled to the second handle 104 at a first link pivot 118 and is pivotally and slidably coupled to the first handle 102 at a slidable pivot 120. The central link 116 interacts with an adjustment thread screw mechanism 122 operably coupled to the first handle 102, the screw mechanism 122 being adapted to adjust the jaw gap between the first jaw 106 and the second jaw 108. As shown, the adjustment screw mechanism 122 may include a head 124 on a first end and a contact surface 126 on a second end opposite the first end, with threads extending at least partially therebetween.

[0018] To adjust the jaw gap between the first jaw 106 and the second jaw 108, the user can rotate the head 124 of the adjustment screw mechanism 122 in the desired rotational direction and move the adjustment screw mechanism 122 axially inward or axially outward relative to the longitudinal axis of the first handle 102 based on the functionality of the thread. For example, for a right-hand screw, the user can rotate the head 124 of the adjustment screw mechanism 122 clockwise, thereby pushing the surface 126 of the adjustment screw mechanism 122 against the face 128 of the center link 116. In doing so, the center link 116 will push the second jaw 108 toward the first jaw 106 at the second jaw pivot 114 in the closing action, thereby reducing the jaw gap between the first jaw 106 and the second jaw 108. Alternatively, by pulling the second jaw pivot 114 in a manner opposite to that described above, the user can rotate the head 124 of the adjustment screw mechanism 122 counterclockwise to increase the jaw gap between the first jaw 106 and the second jaw 108.

[0019] In some embodiments, the tool 100 can be locked or clamped in a manner that fixes the jaw gap between the first jaw 106 and the second jaw 108, thereby clamping to a workpiece disposed between the first jaw 106 and the second jaw 108. To lock or clamp the tool 100, the second handle 104 is moved in a direction toward the first handle 102. The clamping force on the second jaw 108 is transmitted about the pivot 112 and can be modeled as an imaginary line (referred to as a "power line") from the pivot 114 to the contact point 130 between the surface 126 and the face 128. When the second handle 104 is moved toward the first handle 102, the tool 100 is locked or clamped, but the tool 100 is prevented from moving further toward the first handle 102 by the interaction of the protrusion 134 of the center link 116 and the abutment 136 of the release lever 132. As shown, the release lever 132 is coupled to the second handle 104 at the release pivot 138.

[0020] To release the locking function, the tool 100 includes a return link 132 that can be moved away from the second handle 104 and thereby pushed against the center link 116. As shown, the center link 116 may include a protrusion 134, and the release lever 132 may include an abutment 136, which contacts each other to prevent the first handle 102 and the second handle 104 from further closing relative to each other. When the user moves the release lever 132 at the tab 140 on the end of the release lever 132, the abutment 136 can further serve as a first contact point during the release operation. Here, the abutment 136 can contact the protrusion 134 and pry the second handle 104 away from the center link 116 and / or the first handle 102.

[0021] The tool 100 may also include an over-center locking feature, wherein the center link 116 may also include a protrusion that interacts with the release link, such as, for example, an over-center locking feature described in U.S. Patent Application Publication No. 2020 / 0384613, entitled Locking Pliers Release Mechanism, which is commonly held with the present invention.

[0022] However, in existing designs, it may be difficult for a user to apply enough force to the handles of the pliers to lock the pliers and clamp the jaws of the pliers on a workpiece. The present invention solves this problem by setting or placing the first link pivot 118 (the center link 116 is rotatably or pivotally connected to the second handle 104 at the first link pivot) a first distance L1 from the second jaw pivot 114 (the second jaw 108 is rotatably or pivotally connected to the second handle 104 at the second jaw pivot). In addition, the first jaw pivot 112 (the second jaw 108 is rotatably or pivotally connected to the first handle 102 at the first jaw pivot) is set or placed a second distance L2 from the second jaw pivot 114.

[0023] In one embodiment, the first distance L1 is about 34% to about 70% of the second distance L2, preferably about 43.5% of the second distance L2. In addition, a first line extending through the second jaw pivot 114 and the first link pivot 118 and a second line extending through the first link pivot 118 and the contact point 130 are separated by an angle α. In one example, the second distance L2 is about 1.465 inches, the first distance L1 is about 0.5 inches to about 1.0 inches, preferably about 0.637 inches, and the angle α is about 171° to about 172°. Compared to existing designs, this results in an increase in the clamping force of all jaw types commonly found on locking pliers, while the user input force required to lock or clamp the pliers (clamp the first jaw and the second jaw) is lower. For example, in one embodiment, the user requires an input force of about 21.1 pounds to clamp or lock the first jaw and the second jaw of the pliers, while the first jaw and the second jaw provide a clamping force of about 528.8 pounds. This results in a mechanical advantage of 25.1 (ie, the clamping force is approximately 25 times the input force). A mechanical advantage of 25.1 is greater than that provided by conventional designs.

[0024] For example, the first distance L1 is approximately 107%-108% of the second distance L2, requiring approximately 60.1 pounds of input force by the user to clamp or lock the first and second jaws of the pliers, and the first and second jaws provide approximately 460.7 pounds of clamping force, resulting in a mechanical advantage of 7.7. In another example, the first distance L1 is approximately 83% of the second distance L2, requiring approximately 39.3 pounds of input force by the user to clamp or lock the first and second jaws of the pliers, and the first and second jaws provide approximately 488.5 pounds of clamping force, resulting in a mechanical advantage of 12.4.

[0025] As described above, the first jaw 106 and the second jaw 108 may be other types of jaws and include other features. Figure 2, shows a second half of another embodiment of an example pliers, and can include a second jaw 208, the second jaw 208 including a cutting surface. Similar to the example pliers 100 described above, the second half of the pliers includes a second handle 204 and a second jaw 208. The second jaw 208 can be coupled to the first handle at a first jaw pivot 212, and can be coupled to the second handle 204 at a second jaw pivot 214. In one embodiment, the second handle 204 is pivotally coupled to the second jaw 208. The center link 216 is also pivotally coupled to the second handle 204 at the first link pivot 218, and is pivotally and slidably coupled to the first handle at a slidable pivot. The center link 216 interacts with an adjustment screw mechanism 222 operably coupled to the first handle to adjust the jaw gap. As shown, the adjustment screw mechanism 222 can include a head 224 on a first end and a contact surface 226 on a second end opposite the first end, wherein the thread extends at least partially between the two. Surface 226 of adjustment screw 222 abuts face 228 of center link 216 at contact point 230 .

[0026] refer to Figure 3 , shows a second half of another embodiment of an example pliers, and can include a second jaw 308, the second jaw 308 including a substantially flat surface. Similar to the example pliers 100 described above, the second half of the pliers includes a second handle 304 and a second jaw 308. The second jaw 308 can be coupled to the first handle at a first jaw pivot 312, and can be coupled to the second handle 304 at a second jaw pivot 314. In one embodiment, the second handle 304 is pivotally coupled to the second jaw 308. The center link 316 is also pivotally coupled to the second handle 304 at the first link pivot 318, and is pivotally and slidably coupled to the first handle at a slidable pivot. The center link 316 interacts with an adjustment screw mechanism 322 operably coupled to the first handle to adjust the jaw gap. As shown, the adjustment screw mechanism 322 can include a head 324 on a first end and a contact surface 326 on a second end opposite the first end, wherein the thread extends at least partially between the two. Surface 326 of adjustment screw 322 abuts face 328 of center link 316 at contact point 330 .

[0027] Similar to the example pliers 100, the first link pivot 218 / 318 (the center link 216 / 316 is rotatably or pivotally coupled to the second handle 204 / 304 at the first link pivot) is a first distance L1 from the second jaw pivot 214 / 314 (the second jaw 208 / 308 is rotatably or pivotally coupled to the second handle 204 / 304 at the second jaw pivot). In addition, the first jaw pivot 212 / 312 (the second jaw 208 / 308 is rotatably or pivotally coupled to the first handle at the first jaw pivot) is set to be a second distance L2 from the second jaw pivot 214 / 314.

[0028] In one embodiment, the first distance L1 is about 34% to about 70% of the second distance L2, preferably about 43.5% of the second distance L2. In addition, a first line extending through the second jaw pivot 214 / 314 and the first link pivot 218 / 318 and a second line extending through the first link pivot 218 / 318 and the contact point 230 / 330 are separated by an angle α. In one example, the second distance L2 is about 1.465 inches, the first distance L1 is about 0.5 inches to about 1.0 inches, and more specifically about 0.637 inches, and the angle α is about 171° to about 172°. This results in an increased clamping force for all jaw types commonly found on locking pliers compared to existing designs, and a low user force required to lock the pliers.

[0029] As used herein, the term "coupled" and its functional equivalents are not necessarily limited to a direct mechanical connection of two or more components. Instead, the term "coupled" and its functional equivalents mean any direct or indirect mechanical, electrical, or chemical connection between two or more objects, features, workpieces, and / or environmental materials. In some examples, "coupled" also means that one object is integral with another object. As used herein, unless expressly stated otherwise, the term "a" or "an" may include one or more items.

[0030] The matters set forth in the foregoing description and the accompanying drawings are provided by way of illustration only and not by way of limitation. Although particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of the inventor's contribution. The actual scope of the protection sought will be defined in the following claims when viewed in their proper perspective based on the prior art.

Claims

1. A tool having a first handle and a second handle and a first jaw and a second jaw, the tool comprising: a first jaw pivot coupling the second jaw to the first handle; a second jaw pivot coupling the second jaw to the second handle; a center link coupled to the first handle at a slidable pivot and to the second handle at a link pivot, wherein a first distance between the second jaw pivot and the link pivot is 34% to 70% of a second distance between the second jaw pivot and the first jaw pivot; as well as An adjusting screw mechanism having a head located on a first end and a contact point located on a second end and a thread extending at least partially between the head and the contact point, the adjusting screw mechanism being threadably inserted into the first handle for adjusting the gap between the first jaw and the second jaw, wherein a first line extending through the second jaw pivot and the link pivot and a second line extending through the link pivot and the contact point are separated by an angle of 171 to 172 degrees.

2. The tool according to claim 1, wherein: The first distance is approximately 43.5% of the second distance.

3. The tool according to claim 1, wherein: The first distance is 0.5 inches to 1.0 inches.

4. The tool according to claim 1, wherein: The first distance is approximately 0.637 inches.

5. The tool according to claim 1, wherein: The first distance and the second distance provide a clamping force between the first jaw and the second jaw that is approximately 25 times an input force to push the first handle and the second handle together to clamp the first jaw and the second jaw.

6. The tool according to claim 1, wherein: The adjusting screw mechanism is adapted to be rotated clockwise to reduce the gap, and is adapted to be rotated counterclockwise to increase the gap.

7. The tool according to claim 6, wherein: The central link comprises a surface, and wherein a contact point of the adjustment screw mechanism abuts against the surface during an adjustment operation to adjust the gap.

8. The tool according to claim 1, wherein: Further including a release rod, which is rotatably connected to the second handle, and the release rod has an abutment portion protruding from the release rod and an extension portion extending from the end of the release rod, and wherein the central link includes a protrusion protruding from the central link toward the second handle, wherein when the first jaw and the second jaw are in a closed state, the abutment portion abuts against the protrusion, and when the abutment portion is separated from the protrusion, the first jaw and the second jaw are in an open state.

9. A tool comprising: a first handle and a second handle; a jaw coupled to the first handle at a first jaw pivot and to the second handle at a second jaw pivot; as well as a center link coupled to the first handle at a slidable pivot and to the second handle at a link pivot, wherein a first distance between the second jaw pivot and the link pivot is 34% to 70% of a second distance between the second jaw pivot and the first jaw pivot; as well as An adjusting screw mechanism having a head located on a first end and a contact point located on a second end and a thread extending at least partially between the head and the contact point, the adjusting screw mechanism being threadably inserted into the first handle for adjusting the gap between the first jaw and the second jaw, wherein a first line extending through the second jaw pivot and the link pivot and a second line extending through the link pivot and the contact point are separated by an angle of 171 to 172 degrees.

10. The tool according to claim 9, wherein: The first distance is approximately 43.5% of the second distance.

11. The tool according to claim 9, wherein: The first distance is 0.5 inches to 1.0 inches.

12. The tool according to claim 9, wherein: The first distance is approximately 0.637 inches.

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