GB2359268A - Knife Handle - Google Patents

Abstract

An implement such as a knife is formed with a handle comprising a thermoplastic body (12, fig. 5), eg of polypropylene, optionally reinforced with fibres, overmoulded with a second thermoplastic layer 22, also preferably of polypropylene. The body and the overmoulded layer bond together to provide a handle that is dishwasher proof. The body may have exposed portions 21 at the overmoulded layer that provide areas of increased grip.

Description

2359268 1 IMPLEMENTS AND THEIR MANUFACTURE The invention relates to a

method of forming a handle for an implement and to implements with handles.

An implement such as a knife is provided with a handle in the form of a body that can be gripped. It is known to form such a body in one piece, but two piece bodies are also known. It is a problem with two-piece bodies that water can sometimes seep between the parts and this means that the implement can be damaged when used, for example, in a dishwasher.

According to a first aspect of the invention, there is provided a method of forming a handle for an implement comprising providing on the implement a body of a first thermoplastic material and then overmoulding the body with a layer of a second thermoplastic material with the second thermoplastic material bonding to the first thermoplastic material.

The bonding between the body and the layer prevents the ingress of water.

According to a second aspect of the invention, there is provided an implement comprising a handle formed by a body of a first thermoplastic material with a layer 2 of a second thermoplastic material oven-noulded on at least a part of the body to bond to the first thermoplastic material.

The following is a more detailed description of some embodiments of the invention, by way of example, reference being made to the accompanying drawings in which:-

Figure 1 is a side elevation of a knife in a first stage of manufacture having a handle formed by a body of polypropylene moulded around a tang of the knife, Figure 2 Is a part plan view from above of the body of Figure 1, Figure 3 is a section on a line A-A of Figure 1, Figure 4 is a similar view to Figure 1 but showing the knife in a second stage of manufacture with an oven-noulded layer on the body, Figure 5 is a plan view from above of a part of the knife of Figure 4, Figure 6 is a section on the line A-A of Figure 4, Figure 7 is detail B from Figure 6, 3 Figure 8 is a side elevation of a body in a first stage of manufacture of a gadget handle, the operative part of the gadget being omitted, Figure 9 is a plan view from above of the body of Figure 8, Figure 10 is a section on the line A-A of Figure 9, Figure 11 is a similar view to Figure 1 but showing a second stage in the manufacture of the handle in which an overmoulded layer is applied to the body, Figure 12 is a plan view from above of the overmoulded body of Figure 11, Figure 13 is a section on the line A-A of Figure 12 and Figure 14 is detail B from Figure 13.

Referring first to Figure 1, the knife comprises a blade 10 formed integrally with a tang 11 which is surrounded by a body 12 that forms part of a handle. The blade 10 and the tang 11 are of conventional design with a sharpened edge 13 and a back edge 14. The blade 10 is formed from stainless steel.

4 The body 12 is moulded from a suitable thermoplastic material such as polypropylene. The polypropylene may be reinforced by fibres such as glass fibres. The fibres may form 30% of the volume of the body 12.

As seen in Figures 2 and 3, the body 12 is symmetrical about a central plane 15 which is coplanar with the plane of the blade 10. A nib 16 runs around the intersection of the plane 15 with the body 12 as best seen in Figures 1, 2 and 3.

The body 12 is formed on either side of the plane 15 with respective side surfaces 17. Each side surface 17 is formed with an irregularly shaped projection 18 that extends generally normal to the associated side surface 17. As seen in Figure 1, the projection 18 is of generally inverted trapezoidal shape but with side edges formed by linked arcuate sections one of which is indicated at 19 in Figure 1. Each projection 18 has a surface 20 (see Figures 2 and 3) remote from the associated side surface 17 and formed with three rows of part spherical depressions 2 1. These are best seen in Figures 1 and 3. The rows extend generally parallel to the longer sides of the associated projection 18 and each row is offset relative to the next adjacent row or rows.

The knife shown in Figures 1 to 3 is at first stage of manufacture. In a second stage, the knife is placed in a mould (not shown) and a layer of a second thermoplastic material is moulded over the body 12. The second thermoplastic material is a material that, on being overmoulded, bonds chemically to the thermoplastic material of the body 12. The second thermoplastic material may also be polypropylene. As seen in Figures 4 to 7, the overmoulded layer 22 covers both side surfaces 17 of the body 12 but does not cover the nib 16. In addition, as seen in Figures 6 and 7, the overmoulded layer 22 does not cover the depressions 21 so that these portions of the body 12 are exposed through apertures 23 in the overmoulded layer 22, as best seen in Figure 7. As seen in Figures 4 to 7, particularly in Figures 4 and 5, the shape of the overmoulded layer 22 is such to form a handle of suitable dimensions to be readily gripped. The depressions 21 provide both a decorative feature and zones that increase the grip between a hand and the handle.

The plastics material of the overmoulded layer 22 may be a different colour from the plastics material of the body 12 so as to provide a further decorative feature.

The projections 18 provide a key between the body 12 and the ovennoulded layer 22. This helps retain the overmoulded layer 22 on the body 12.

Referring next to Figures 8 to 15, there is shown a handle for a gadget; for example a kitchen gadget such as a peeler or a corer or any other form of kitchen tool. The gadget handle is formed from a body 25 moulded from a suitable thermoplastics material such as polypropylene. The polypropylene may be reinforced by fibres such as glass fibres. The fibres may form 30% of the volume of the body 25.

6 As seen in Figures 8, 9 and 10, the body 25 Is symmetrical about a central plane 26.

The body 25 includes a mounting portion 27 at one end, a boss 28 at the end opposite the mounting portion 27 and a central section 29 extending between the mounting portion 27 and the boss 28. The mounting portion 27 has converging side walls 30 and converging upper and lower walls 31 that meet at a tip 32 and is provided with a central eye 33 that, for example, allows the gadget to be hung on a hook on a rack (not shown). The boss 28 is, as seen in Figure 9, generally D-shaped in plan with a convex edge 34 as viewed in side elevation in Figure 8 at its junction with the central section 29. The central section 29 is of generally oval cross-section (see Figure 11) but with an upper rib 35 and a lower rib 36 extending between the mounting portion 27 and the boss 28 and symmetrically disposed about the central plane 26. As seen in Figure 9, the width of the central section 29 Is less than the width of both the mounting portion 27 and the boss 28.

The central section 29 thus has two generally C-shaped side walls 37 extending between the upper rib 35 and the lower rib 36. As best seen in Figure 8, each side wall 37 is provided with 12 projections 38 extending normal to the associated side wall and arranged on a central section of each side wall 37 towards the boss 28. The projections are disposed about the intersection of the side walls 37 with a plane 39 (Figure 8) normal to the central plane 26 and extending through the centre line 40 of the body 25. A first group of six projections 38 are to one side of the intersection and a second group of six projections 38 to the other. One projection 38a of each group 7 of six projections is circular. The remaining five projections 38b of each group are formed by a pair of circular portions 42 connected by a central narrower portion 43. The five projections 38b of each group have the length of each projection 29 angled relative to the intersection, and the projections 38b of one group angled in a direction opposite to the direction of the projections 38b of the other group. The two circular projections 38a are adjacent the boss 28 and are provided with a single part-spherical depression 34 whereas the remaining projections 38b are provided with two partspherical projections 44, as seen in Figures 8 and 10.

It will be appreciated that, in use, the body 25 will be moulded around a tang (not shown) of the implement of which it is to form a handle. The implement extends from the boss 28.

The formation of the body 25 is the first stage in the manufacture of the handle. In a second stage, the body 25 is placed in a mould (not shown) and a layer of a second thennoplastic material is moulded over the body 25. The second thermoplastic material is a material that, on being overmoulded, bonds chemically to the thermoplastic material of the body 25. The second thermoplastic material may also be polypropylene. As seen in Figures 11 to 15, the overmoulded layer 45 covers both side walls 37 of the body 25 but does not cover the upper or lower ribs 35,36. In addition, as seen in Figures 14 and 15, the overmoulded layer 45 does not cover the depressions 44 so that these portions of the body 25 are exposed through apertures 46 8 in the overmoulded layer 45 as best seen in Figure 14. As seen in Figures 8 to 14, particularly in Figures 8 and 9, the shape of the overmoulded layer 45 is such as to form a handle of suitable dimensions to be readily gnipped. The depressions 44 provide both a decorative feature and zones that increase the gnip between a hand and the handle.

The plastic material of the overmoulded layer 45 may be a different colour from the plastic matenial of the body 25 so as to provide a further decorative feature. The projections 38 provide a key between the body 25 and the over-moulded layer 45. This helps to retain the overmoulded layer 45 on the body 25.

It will be appreciated that there are a number of variations that can be made to the arrangement descnibed above. The implement need not be a knife or a gadget; it could be any form of implement such as scissors, tools, whisks, spoons or any item including a handle such as a saucepan. The overmoulded layer 22,45 need not cover just portions of the body 12,25; it could cover the whole body 12,25. The projections 18,38 need not be as shown; they could have any suitable shape. The grip need not be formed by depressions 2 1; it could be formed by projections or any other suitable configuration.

The bonding of the thermoplastic material of the body 12-25 to the thermoplastic material of the oven-noulded layer 22;45 ensures that water cannot seep between the 9 body 12;25 and the overmoulded layer 22;45. Thus the implement can be washed in a dishwasher without damage.

Claims (1)

1. A method of forming a handle for an implement comprising providing on the implement a body of a first thermoplastic material and then overmoulding the body with a layer of a second thermoplastic material with the second thermoplastic material bonding to the first thermoplastic material.

2. A method according to claim 1 wherein the body has an exterior that includes at least one projection providing a key between the body and the overmoulded material, 3. A method according to claim 2 wherein the at least one projection has at least a portion thereof that is exposed through an associated opening in the overmoulded material.

4. A method according to claim 2 or claim 3 wherein the body has a surface covered by the overmoulded material, the at least one projection extending generally normal to said surface.

5. A method according to claim 4 wherein the at least one projection has a surface remote from said surface, said surface including at least one depression exposed through an associated opening in the overmoulded material.

11 6. A method according to claim 5 wherein at least one depression is part spherical.

7. A method according to any one of claims 2 to 7 wherein a plurality of said depressions are provided on the projection.

8. A method according to claim 7 wherein the body is elongate and symmetrical about a central plane, each side of the body being provided with a surface formed with a respective projection including said depressions.

9. A method according to claim 8 wherein the depressions are arranged in respective arrays on each said surface, the arrays being identical.

10. A method according to claim 8 wherein the body includes a rib extending along at least a portion of the intersection of the plane of symmetry of the body with the exterior of the body, the rib being uncovered by the overmoulded material.

A method according to any one of claims 1 to 10 wherein both the body and the overmoulded material are of polypropylene.

12. A method according to claim 11 wherein the polypropylene of the body is filled with glass fibres.

13.

12 A method of forming a handle substantially as hereinbefore described with reference to the accompanying drawings.

14. An implement comprising a handle formed by a body of a first thermoplastic material with a layer of a second thermoplastic material overmoulded on at least a part of the body and bonded to the first thermoplastic material.

15. An implement according to claim 14 and including an operative part, the operative part including a connection portion with the body being moulded around the connecting portion.

16. An implement according to claim 15 wherein the body is symmetrical about a central plane with respective side faces on each side of the plane, the body being formed, on each side face, with at least one projection which forms a key with the oven-noulded material.

17. An implement according to claim 16 wherein each projection has a surface remote from the body, a portion of each said surface being exposed through an associated opening in the overmoulded material.

An implement according to claim 17 wherein each said portion of the projection comprises a depression.

13 19. An implement according to claim 18 wherein a plurality of depressions are arranged in an array on the associated projection.

20. An implement according to claim 19 wherein the arrays of depressions on each side of said central plane are identical.

21. An implement according to any one of claims 16 to 20 wherein the body includes a rib extending along at least a portion of the intersection of the plane of symmetry of the body with the exterior of the body, the rib being uncovered by the oven-noulded material.

22. An implement according to any one of claims 14 to 21 wherein both the body and the overmoulded material are of polypropylene.

23. An implement according to claim 22 wherein the polypropylene of the body is filled with glass fibres.

24. An implement according to any one of claims 14 to 23 wherein the implement is a knife.

25. An implement substantially as hereinbefore described with reference to the accompanying drawings.