GB2351466A

GB2351466A - A tool which may be used for gripping and/or cutting

Info

Publication number: GB2351466A
Application number: GB9929333A
Authority: GB
Inventors: Yin Hong Wong
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-28
Filing date: 1999-12-10
Publication date: 2001-01-03
Anticipated expiration: 2019-12-10
Also published as: GB9914872D0; GB9929333D0; GB2351466B

Abstract

A tool 11 comprises first and second elongate operating elements 12, 13 each having a handle portion at one end 14, 15 and a working portion at the other end 16, 17. Pivotal coupling means 18 couple the operating elements together in such a manner that movements of the handle portions towards and away from each other produce corresponding movements of the working portions towards and away from each other. The pivotal coupling means comprises first and second elongate coupling elements 22, 23 each being coupled at one end to the first operating element and at the other end to the second operating element. The elongate coupling elements are positioned to cross each other between the operating elements and are coupled to each other at the crossover. Preferably the pivotal coupling means allows the operating elements to remain substantially parallel to one another during relative movement. The tool may be a gripping and/or cutting tool such as a pair of pliers (see fig 13) or a pair of wire cutters.

Description

2351466 OPERATING TOOL The present invention relates to an operating tool,

particularly but not exclusively a gripping and/or cutting tool such as a pair of pliers or a pair of wire 5 cutters.

Pliers and wire cutters conventionally operate by having first and second elongate operating elements each having a handle portion at one end of the operating element and a working portion at the other end of the operating element, and a pivot pin coupling the two operating elements together at a position intermediate their ends, in the manner of a pair of scissors. The effect of this is that when the working portions move towards each other, for example the gripping jaws of a pair of pliers, the gripping faces of the jaws approach each other at an angle which varies as the jaws are closed.

It is an object of the invention to provide an improved operating tool providing increased control over the geometry of the working portions of the operating tool which move towards and away from each other in normal use.

According to the present invention there is provided an operating tool comprising first and second elongate operating elements each having a handle portion at one end of the operating element and a working portion at the other end of the operating element, and pivotal coupling means coupling the operating elements together in such a manner that movements of the handle portions towards and away from each other produce corresponding movements of the working portions towards and away from each other, in which the pivotal coupling means comprises first and second elongate coupling elements each being coupled at one end thereof to the first operating element and at the other end thereof to the second operating element, the elongate coupling elements being positioned to cross each other between the operating elements and being coupled to each other at the crossover.

P7674GB 2 The invention has particular application where the tool constitutes a gripping tool in which the said working portions comprise a pair of gripping jaws, for example a pair of pliers. Another application of the invention arises where the tool constitutes a cutting tool in which the said working portions comprise at least one cutting blade, for example a cutting blade abutting against an anvil, or a pair of cutting blades cooperating.

In a convenient arrangement according to the invention, each coupling element is pivotally coupled to one operating element at one end of the coupling element and is pivotally coupled to the other operating element at the other end of the coupling element. Preferably each coupling element is coupled at at least one end thereof to the respective operating element by a pivotal linkage allowing both rotary movement and translational movement of the coupling element relative to the operating element. By way of example, each pivotal linkage may comprise a pivot pin mounted in a track on the respective elongate operating element, allowing translational movement of the pivot pin along the track as well as pivotal movement of the coupling element relative to the operating element. Preferably each coupling element is coupled at one end of the coupling element to a respective operating element by the said pivotal linkage allowing rotary and translational movement and at the other end of the coupling element to a respective operating element by a pivotal component which allows only rotary movement, most preferably it being arranged that the two said pivotal components are positioned on their respective operating elements on one side of the crossover point and the two said pivotal linkages are positioned on their respective operating elements on the other side of the crossover point.

It is particularly preferred that the distance between the positions at which the first coupling element is coupled to the first and second elongate operating elements is equal to the distance between the positions at which the second coupling element is coupled to the first and second elongate operating elements, and the position at which the elongate coupling elements cross each other is for each coupling element mid way between the two said positions at which it is coupled to the operating elements.

P7674GB 3 Preferably the pivotal coupling means is such that during movement of the operating elements relative to each other, the operating elements remain at a fixed angle relative to each other, most preferably substantially parallel to each 5 other.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:- Figure 1 is a plan view from above of a pair of pliers embodying the present invention; Figure 2 is a side view of the pliers shown in Figure 1, taken in the direction I in Figure 1; 15 Figure 3 is a section of jaws of the pliers, taken along the lines 111- 111 in Figure 1; Figure 4 shows the pliers as in Figure 1, but in the closed position, and 20 with hidden components shown in broken lines; Figure 5 is a section along the lines V-V in Figure 4; Figure 6 shows in diagrammatic detail a side view of a pivot pin shown in 25 Figure 4; Figure 7 shows first and second coupling elements of the pliers shown in the preceding Figures; Figures 8 and 9 are respectively side views of the second and first coupling elements of Figure 7; P7674GB 4 Figures 10 and 11 are respectively plan views of the second and first coupling elements; Figure 12 shows a known pair of pliers forming part of the prior art; and

Figures 13 shows a manner of use of pliers embodying the invention, to grip a nut.

Referring first to Figures 1, 2 and 3, a pair of pliers 11 embodying the invention comprise first and second elongate operating elements 12 and 13 having handles 14, 15 respectively, and jaws 16, 17 respectively. The elongate operating elements are coupled together by pivotal coupling means 18 in such a manner that movements of the handles 14 and 15 towards and away from each other produce corresponding movements of the jaws 16 and 17 towards and away from each other. The handles 14 and 15 constitute handle portions of the operating elements and the jaws 16 and 17 constitute working portions of the operating elements 12 and 13. Figure 3 shows a cross section through the jaws 16, 17 taken along the line The jaw 16 comprises an upper gripping portion 19 and a blade 20 at right angles thereto for cutting. The jaw 17 has corresponding components 21 and 22 respectively.

As shown in Figures 4 to 11, the coupling means 18 comprises first and second elongate coupling elements 22, 23. As shown in Figures 7 to 11, the first coupling element 22 has a stud or pivot pin 24 at one end thereof and a pivot hole 25 at the other end thereof. Mid-way between the ends is a pivot boss 26 rising from a pivot base 27 of circular shape linking to sides of the elongate coupling element 22. The second elongate coupling element 23 has a stud or pivot pin 28 at one end thereof and a pivot hole 29 at the other end. At the centre of the second elongate element 23 a pivot base 30 has a central pivot hole 31 having a clearance fit with the boss 26 of the first coupling element 22.

As shown in Figures 7, when assembled the pivotal coupling means 18 has the two coupling elements 22 and 23 fitted together with the boss 26 in pivoting P7674GB relation with the hole 31, the two coupling elements 22 and 23 crossing each other at the mid-points thereof.

As shown in Figures 4, 5 and 6, the ends of the coupling elements 22 and 23 which are remote from the jaws 16 and 17, are pivoted to the handles 14 and by pivot pins 32 and 33 which pass through the handles and through respective holes 25 and 29 of the coupling elements 22 and 23. The ends of the coupling elements 22 and 23 which are closer to the jaws 16 and 17 are coupled to the operating elements 12 and 13 by the pins 28 and 24 respectively. As shown in Figure 5, the operating element 12 has a hollow interior formed by an elongate groove 34 which has a T-shaped cross section. A corresponding groove 35 is provided in the operating element 13. The pins 24 and 28 lodge respectively in the grooves 35 and 34 allowing pivoting movement, and translational (or lateral) movement along the respective groove. The pins 24 and 28 in combination with their respective grooves 35 and 34 constitute pivotal linkages allowing both rotary movement and translational movement of the respective coupling elements. The pins 32 and 33 constitute pivotal components which allow only rotary movement.

The overall operation of the pliers embodying the invention is that as the handles 14 and 15 are moved together or apart, the coupling elements 22 and 23 pivot about the pins 32 and 33 and pivot relative to each other about the boss 26.

At the same time the studs 28 and 24 move along the grooves 34 and 35 respectively so that the jaws 16 and 17 move towards and away from each other while remaining parallel to each other. A number of advantages arise in various situations, for example giving improved cutting by the cutting part of the jaws.

Another example of the advantage derived is illustrated with reference to Figures 12 and 13. With a conventional form of pliers 10 as shown in Figure 12, a nut can be gripped only by one jaw matching with a flat of the nut, and the other jaw resting upon an edge between two flats. As shown in Figure 13, with the present invention the nut may be gripped by the jaws both gripping flats of the nut.

P7674GB -21 6 A number of details of operation will now be described with reference to the drawings generally.

In operation, when the handles 14, 15 move towards or away from each other as shown in Figures 1 and 4, the face of upper jaw 16 and the face of lower jaw 17 are parallel at any instant. The cylindrical metal studs 28, 24 are installed in the 'T' channels 34, 35 of the upper and lower elements 12, 13 and are free to slide along the 'T' channels. The pins 32, 33 are used to thread through the circular openings of the upper element 12 and also the lower element 13. This arrangement will allow rotary movement for elements 22 and 23 but no lateral movement at the holes 25 and 29. However, lateral movement is possible for the elements 22 and 23 at the other ends with the cylindrical metal studs 24, 28.

When the upper and lower handles are pressed together, the stud 28 of element 22 and that of element 23 will force the part of the operating elements near the jaws to close and thus force the jaws to close while maintaining the jaws parallel to each other. Figure 7 shows the Y piece where element 23 rotates on element 22. In Figure 7, if the centres of the components 24, 25, 26, 28 and 29 are indicated respectively as p2, hl, cl, pl and h2, then the length of clhl=clp2=clh2=clpl, and also hlp2 equals to plh2. Whenthecoupling elements 22 and 23 move towards each other as indicated by arrows A, the angle formed by the line hlcl and cl U will vary, and also the angle pl cl p2 is equal to angle hlclh2 since the length clhl=clh2=clp2=clpl. Thereforethe broken line plhl is parallel to the line p2h2 because alternate angle plhlcl is equal to angle h2p2cl. The arrows B show how the element 22 moves away from the element 23. The broken line pl hl is equal and parallel to the broken line h2p2 when the elements 22, 23 are moved to any position. Hence the upper jaw is always parallel to the lower jaw of the pliers at any position since the face of the upper jaw is parallel to the face of the lower jaw. Similarly handles 14 and 15 are also parallel to the faces of the jaws as shown in Figure 1. In fact the lower handle is a mirror image of the upper handle except at the cutting part of the jaw where the wedge shaped cutting part is on the same side as on the upper jaw as shown in Figure 3 sectioned along line P7674GB The jaws of the conventional pliers of Figure 12 will form a 'v' shape for various positions of the handles as shown in Figure 12, when the handles are moved. Therefore it is not possible for the jaws to grip properly the two opposite faces which are parallel to each other of a nut since the nut has three sets of parallel faces. The present invention can overcome this problem.

P7674GB =001 8

Claims

1 An operating tool comprising first and second elongate operating elements each having a handle portion at one end of the operating element and a working portion at the other end of the operating element, and pivotal coupling means coupling the operating elements together in such a manner that movements of the handle portions towards and away from each other produce corresponding movements of the working portions towards and away from each other, in which the pivotal coupling means comprises first and second elongate coupling elements each being coupled at one end thereof to the first operating element and at the other end thereof to the second operating element, the elongate coupling elements being positioned to cross each other between the operating elements and being coupled to each other at the crossover.

2. A tool according to Claim 1 in which each coupling element is pivotally coupled to one operating element at one end of the coupling element and is pivotally coupled to the other operating element at the other end of the coupling element.

3. A tool according to Claim 2 in which each coupling element is coupled at at least one end thereof to the respective operating element by a pivotal linkage allowing both rotary movement and translational movement of the coupling element relative to the operating element.

4. A tool according to Claim 3 in which each pivotal linkage comprises a pivot pin mounted in a track on the respective elongate operating element, allowing translational movement of the pivot pin along the track as well as pivotal movement of the coupling element relative to the operating element.

5. Apparatus according to Claim 3 or 4 in which each coupling element is coupled at one end of the coupling element to a respective operating element by the said pivotal linkage allowing rotary and translational movement and at the P7674GB 9 other end of the coupling element to a respective operating element by a pivotal component which allows only rotary movement.

6. A tool according to Claim 4 or 5 in which the two said pivotal components are positioned on their respective operating elements on one side of the crossover point and the two said pivotal linkages are positioned on their respective operating elements on the other side of the crossover point.

7. A tool according to any preceding claim in which the distance between the positions at which the first coupling element is coupled to the first and second elongate operating elements is equal to the distance between the positions at which the second coupling element is coupled to the first and second elongate operating elements, and the position at which the elongate coupling elements cross each other is for each coupling element mid way between the two said positions at which it is coupled to the operating elements.

8. A tool according to any preceding claim in which the pivotal coupling means is such that during movement of the operating elements relative to each other, the operating elements remain at a fixed angle relative to each other.

9. A tool according to Claim 8 in which the pivotal coupling means is such that during movement of the operating elements relative to each other, the operating elements remain substantially parallel to each other.

10. A tool according to any preceding claim, constituting a gripping tool in which the said working portions comprise a pair of gripping jaws.

11. A tool according to any of Claims 1 to 9, constituting a cutting tool in which the said working portions comprise at least one cutting blade.