GB2468705A

GB2468705A - Cable cutting knife

Info

Publication number: GB2468705A
Application number: GB0904736A
Authority: GB
Inventors: Jason Bull; Steve Ali
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-19
Filing date: 2009-03-19
Publication date: 2010-09-22
Also published as: GB0904736D0

Abstract

A handheld knife 100 comprises a cutting blade 103, a handle 102 and a guide, the blade extending forward of the handle 102 and the guide extending forward of the handle and on either side of the blade 103. In use, the guide engages against a cable sheath (101, figure 1) on either side of the longitudinal centreline so as to constrain the blade to cut along the length of the cable. The guide may comprise at least two preferably retractable guide members (104, figure 1) positioned on either side of the blade. Each guide member may have a substantially flat face (108, figure 1) opposing a blade face. The guide may comprise a first guide face 109 integrally formed as part of the knife body with a convex V-shaped profile extending from the handle. The first guide face preferably extends along the entire length of the knife body. A second guide face 110 may be spaced apart from the first guide face so that their centre lines are longitudinally aligned. Preferably the first guide face extends forwardly of the handle at the cutting end and the second guide face extends rearwardly at the opposite end.

Description

I

CABLE SHEATH CUTTING TOOL

The present invention relates to a handheld knife with adjustable blade and guides arranged such that, in use, said knife is constrained to cut along the length of a cable sheath at a set depth and distance from the sheath's edge.

Guided handheld cutting tools exist in many different forms, with the desirable characteristics including replaceability of blade, ergonomic conformity of the handle, adjustability of cutting depth and ease and reliability of use.

US Patent 4,744,146 is one such example of prior art in this field and describes an adjustable blade safety knife with a cutting guide -the knife being designed for opening cardboard containers. The body of said knife handle is fitted with a rigid U-shaped guide member extending forward from the cutting end and on one side of the knife. The guide member is spaced apart from the blade and angled relative thereto so that when the face of the blade is brought into contact with the cardboard container the blade is constrained to cut at a set distance from the side of the container and at an inclined angle.

This device, however, is not effective on a curved plane or surface and is able to cut parallel to, but only at a set, non-adjustable distance from, the edge of the item to which it is constrained.

According to the present invention there is provided a handheld knife for cutting along the length of a curved surface, such as a cable sheath, or the like, composed of a cutting blade, a handle and a guiding means, the blade extending forward of the handle and the guiding means extending forward of the handle and on either side of the blade such that, in use, the guiding means engage against the cable sheath on either side of the longitudinal centreline so as to constrain movement of the handle parallel to said longitudinal axis and thereby constrain the blade of the knife to cut substantially parallel to the cable edge and along the length of said cable.

A handheld knife in accordance with the invention has the advantage that the guiding means increase the footprint of the blade, constraining it to cut at a set depth and stabilising the cutting motion to enable a controlled cut.

In a first preferred embodiment of the invention the guiding means comprises at least two guide members and said guide members preferably oppose each other with the blade positioned therebetween. Further advantageously each guide member has a substantially flat face opposing a blade face. Preferably the blade lies parallel to the opposed guide member faces and along the centreline between said opposing faces, thus, in use, constraining the knife to cut along the centreline of the cable sheath.

Advantageously, the position of the blade relative to each guide member is adjustable. The extension of said blade from the handle may be adjustable such that whilst the guide members constrain the blade to cut in a substantially straight line along the length of a curved surface, said guide members, combined with the provision of an extendable blade, enable the knife to be used on flat surfaces -the increased footprint offering improved cutting stability. The blade, preferably, is retractable into the handle of the knife for safe storage after use.

Further advantageously the extension of each guide member from the handle is adjustable. Said guide members extension in particular may be slidably adjustable.

Furthermore, the extent to which the guide members splay out from the handle astride the blade may be adjustable so that said guide members can accommodate various degrees of cable thickness. Advantageously the guide members are resiliently deformable such that a wide range of cable thickness can be accommodated. The guide members advantageously are retractable to a non-splayed out position such that they can be secured proximate to the knife handle for ease of storage after use.

The adjustability of the extension of the blade, the extension of the guide members from the handle and or the separation of the guide members allow the depth to which the knife can cut to be set. Preferably, a depth gauge on the blade or knife body indicates the depth of penetration of the blade with the cable sheath or the like.

The knife is preferably coated with a non-stick coating, for example TeflonTM, such that it will pass between the cut cable sheaths easily and rollers may, advantageously, be positioned proximate to the tip of the blade to further help the blade travel along the cable sheath. The blade may also be able to rotate about its longitudinal axis relative to the handle, for example snapping to specific angles such as 45 degrees and or 90 degrees, for angular cutting.

The knife may also have two or more blades which work in conjunction to aid stripping of the cable sheath and, furthermore, have vertically opposing blades to, advantageously, enable the knife to cut opposing surfaces without turning said knife over.

In a second preferred embodiment of the invention the guiding means is integrally formed as part of the knife body. Advantageously, the guiding means comprises at least one guide face with a convex V-shaped profile extending from the handle. Preferably, two guide faces are integrally formed as part of the knife body and longitudinally spaced from each other along the knife. The first guide face preferably extends forward of the handle, proximate to the cutting end of the knife, and the second guide face extends rearward, at the opposite end of the handle, preferably remote from the cutting end.

Furthermore, it will be appreciated that, alternatively, a single guide face could be provided that extends substantially along the entire length of the knife body.

The knife blade, advantageously, lies along the centreline formed by the apex of the V-shaped profile of the first guide face and the extension of the blade from said guide face is adjustable. Similar to the first embodiment, preferably a depth gauge or the like on the blade or knife body indicates the cutting depth of said knife.

Preferably, the handle of the knife is arched relative to the horizontal such that the apex of the V of the second guide face is in the same horizontal plane as the apex of the V of the first guide face. Further advantageously the centrelines of each guide face are aligned. Furthermore, the arched nature of the handle provides, in use, clearance, such that a user may grip the handle whilst engaging both guide faces of the knife with the cutting surface.

The position of the integrally formed guiding means of the second embodiment is, preferably, not adjustable, but, as with the first embodiment, the extension of the blade relative to said guiding means is adjustable. Similar to the first embodiment, the guiding means of the second embodiment may be formed from a resiliently deformable material so as to accommodate a wide range of surface curvatures or act to stabilise the knife when used on substantially flat surfaces.

It would be appreciated that any combination of the guiding means of the first and second embodiments may be used in conjunction such that the knife could be constrained to cut parallel to the edge of a curved surface or to offer stability when cutting on a substantially flat surface. Similarly, any combination of other features of the first embodiment could, advantageously, be used in conjunction with those of the second embodiment.

In order that the invention may be well understood, there will now be described an embodiment thereof, given by way of example, reference being made to the accompanying drawing, in which: Figure 1 is a perspective view of the apparatus according to a first preferred embodiment of the invention, showing the knife in use on a cable sheath; Figure 2(a) is a perspective view of the apparatus of the invention according to a second preferred embodiment, showing the alternate guiding means; and Figure 2(b) is a perspective view of the apparatus of the invention according to the second preferred embodiment, showing the knife in use on a cable sheath.

Referring to Figure 1, there is shown a first embodiment of a handheld knife 1 0 for effecting controlled cutting of a sheath 101 of a cable along its length. The knife 100 comprises a handle 102, a blade 103 and a pair of guide members 104.

The handle 102 is ergonomically shaped for gripping, with the blade 103 extending forward of the cutting, or front end, 105. The blade 103 extends from a centrally positioned slot in the front end 105 of the handle 102 and is slidably mounted within the body of said handle 102 such that the extension of the blade 103 from the front end 105 of the handle 102 can be adjusted and said blade 103 can also be withdrawn into the body of the handle 102. Such extendable and retractable blade mechanisms are within the practical knowledge of the skilled person and will not, therefore, be described here in greater detail.

On opposing sides of the handle 102 is a pair of guide members 104. Each guide member 104 comprises a thin, planar, resiliently deformable material with a top end 106 and a bottom end 107, the bottom end 107 being wider than the top 106 to form a substantially spatula-like shape. The top end 106 of each guide member 104 is slidably mounted to the handle 102 proximate to the blade 103. The bottom end 107 of each guide member 104 is remote from the handle 102.

The two guide members 104 each have a substantially flat face 108 proximate to, and facing inward toward, the blade 103 and are slidably mounted on opposite sides of the handle 102 such that the faces 108 oppose each other on either side of the blade 103.

The blade 103 lies parallel to the opposed guide member faces 108 and along the centreline between said opposing faces 108, thus, in use, being constrained to cut equidistant from both guide member faces 108.

As previously described, the guide members 104 are slidably mounted to the handle 102. The extent to which the bottom end 107 of each guide member 104 extends forward of the handle 102 is therefore slidably adjustable. The perpendicular distance between the two bottom ends 107 of the guide members 104 and thus their separation on either side of the blade 103 is also slidably adjustable. It will also be apparent to those skilled in the art that the guide members 104 could be extended and retracted independently of each other, thereby constraining the blade 103 to cut at a different set distance from either one. Similarly, the guide members 104 could be extended and retracted by equal amounts, thereby constraining the blade 103 to cut equidistant from either one.

A ratchet mechanism enables controlled adjustment of the position of either guide member 104. Such a mechanism is, again, well known in the art so will not be described here in greater detail. It will also be apparent that numerous types of adjustable mount could be used.

The blade 103 and handle 102 may optionally be integrally formed, and although not shown in the illustrated embodiment the blade 103 may also be rotatable within the handle 102, enabling cuts to be made at an angle. The handle 102 may also be formed of a soft deformable material that, through use, conforms to the users hand.

In an alternate preferred embodiment, as shown in Figure 2, the pair of guide members 104 as shown in Figure 1 are replaced by a first guide face 109 and second guide face 1 10. Both first and second guide faces 109, 110 are integral to the body of the knife 100 and formed at opposite ends of the knife handle 102. The guide face 109 extends forward of the handle 102 and either side of the blade 103 so as to form a convex V-shaped profile with the blade 103 positioned along the centreline, or apex, of said V-shaped profile. The second guide face 110 extends rearward at the opposite end of the handle 102 and has a similar convex V-shaped profile to that of the first guide face 109. The first and second guide faces 109, 110 are oriented such that the apex of the V-shaped profile of each lies in the same horizontal and vertical plane and the handle 102 is arched relative to the horizontal such that when, in use, both guide faces 109, 110 engage a cutting surface a clearance between said cutting surface and handle 102 is maintained such that a user can grip said handle 102.

It will be appreciated that a combination of the guide members 104 of the first embodiment of the invention could be used in conjunction with a guide face or faces 109, 110 of the second embodiment. It will also be appreciated that many different variations of guide faces 109, 110 size and position are possible and, similarly, many different variations of guide member 104 position and method of adjustment are possible, as well as the position and adjustable nature of the blade 103 within handle 102.

Similarly, it will also be appreciated that many different variations of the apparatus as a whole are possible. For example, the blade 103 type, position and number could vary or the guided cutting could be achieved through numerous means, for example a curved face instead of a V-shaped face integrally formed on the handle 102 at the head of the knife 100. The knife 100 could further include a light to aid use in the dark and or a removable strap to secure the knife 100 to the cutting surface during use.

A level to aid accurate cutting could be incorporated into the apparatus and it would also be apparent that known devices such as a wheel and controlling arm to enable cutting in a circle could also be integrated into the knife 100.

Finally, it is understood that the knife 100 could be used on things other than a cable sheath 101, for example in the kitchen on foodstuffs and the guided cutting could help not only the able-bodied, but also the elderly and infirm.

Claims

CLAIMS: 1. A handheld knife comprising a first cutting blade, a handle and a guiding means, the blade extending forward of the handle and the guiding means extending forward of the handle and on either side of the blade such that, in use, the guiding means engage against a cable sheath on either side of the longitudinal centreline so as to constrain movement of the handle parallel to said longitudinal axis and thereby constrain the blade of the knife to cut substantially parallel to the cable edge and along the length of said cable.
2. A handheld knife according to Claim 1, wherein the guiding means comprises at least two opposed guide members with the blade positioned therebetween. *..* * . S...
3. A handheld knife according to claim 1 or 2, wherein the guiding means S.....104 is integrally formed as part of the knife body.
4. A handheld knife according to Claim 2, wherein the extension of the guiding members from the handle is adjustable.

S

*5*S*S * S
5. A handheld knife according to Claim 4, wherein the extension of the guiding members from the handle is slidably adjustable.
6. A handheld knife according to claim 4 or 5, wherein the guiding members are retractable such that they can be secured proximate to the knife handle for ease of storage after use.
7. A handheld knife according to any of claims 2 to 6, wherein each guide member has a substantially flat face opposing a blade face, the blade lying parallel to the opposed guide member faces and along the centreline between said opposing faces, thus, in use, constraining the knife to cut along the centreline of the cable sheath.
8. A handheld knife according to any of claims 2 to 7, wherein the extent to which the guide members splay out from the handle astride the blade isadjustable.
9. A handheld knife according to claim 1, wherein the guiding means comprises at least a first guide face, integrally formed as part of the knife body and with a convex V-shaped profile extending from the handle.
10. A handheld knife according to Claim 9, wherein the knife blade lies along the centreline formed by the apex of the V-shaped profile of the at least first guide face. * .
11. A handheld knife according to claim 9 or 10, wherein the at least first guide face extends substantially along the entire length of the knife body. ***

*:
12. A handheld knife according to claim 9 or 10, wherein a second guide * face longitudinally spaced apart from the first guide face along the knife is integrally formed as part of the knife body and the centrelines of each guide face are longitudinally aligned.
13. A handheld knife according to claim 12, wherein the first guide face extends forward of the handle, proximate to the cutting end of the knife, and the second guide face extends rearward, at the opposite end of the handle, remote from the cutting end, the handle arched such that the apex of the V of the second guide face is in the same plane as the apex of the V of the first guide face.
14. A handheld knife according to Claim 13, wherein the handle is arched so as to, in use, define a gripping section spaced apart from the common plane of the first and second guide faces of the knife.
15. A handheld knife according to any of the preceding claims, wherein the extension of the blade from the handle is adjustable.
16. A handheld knife according to any of the preceding claims, wherein the blade is retractable into the handle of the knife for safe storage after use
17. A handheld knife according to any of the preceding claims, wherein the position of the blade relative to the guiding means is adjustable. * * S...
18. A handheld knife according to any of the preceding claims, wherein the :.. guiding means is resiliently deformable such that a wide range of cable * thickness can be accommodated. *.:
19. A handheld knife according to any of the preceding claims, wherein a * : * * depth gauge on the blade or knife body indicates the depth of penetration of the blade with the cable sheath or the like.
20. A handheld knife according to any of the preceding claims, wherein the blade is coated with a non-stick coating, for example TeflonTM.
21. A handheld knife according to any of the preceding claims, wherein rollers are positioned proximate to the tip of the blade to help the blade travel along the cable sheath.
22. A handheld knife according to any of the preceding claims, wherein the blade is rotatable about its longitudinal axis relative to the handle.
23. A handheld knife according to claim 22, wherein the rotatable blade can be snapped to specific angles for angular cutting.
24. A handheld knife according to any of the preceding claims, wherein at least the first blade works in conjunction with at least a second blade to strip the cable sheath.
25. A handheld knife according to any of the preceding claims, further including a cutting blade vertically opposed the first blade such that opposing surfaces can be cut without turning said knife over. S.. * * *..*26. A handheld knife as herein described with reference to the accompanying drawings. S.. S... * S* S. *S..'.. S *