NZ515491A

NZ515491A - Shearing comb with square gullet

Info

Publication number: NZ515491A
Application number: NZ51549101A
Authority: NZ
Inventors: Philip David Jones
Original assignee: Heiniger Ltd
Priority date: 2000-11-22
Filing date: 2001-11-16
Publication date: 2002-05-31
Also published as: AUPR164200A0

Abstract

A shearing comb comprising a comb body and a plurality of teeth formed integrally therewith and projecting forwardly therefrom. The comb has top and bottom surfaces. The comb has at least a first groove formed therein between adjacent teeth. The first groove defines a gullet with the angle of the gullet relative to the top surface of the comb being 90°. The grinding of the top surface to sharpen the comb does not affect the angle of the gullet with respect to the top surface.

Description

PATENTS FORM NO. 5 Fee No. 4* $250.00 Our ref: 27003/5 HB INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 6 NOV 2001 RECEIVED PATENTS ACT 1953 COMPLETE SPECIFICATION SHEARING COMB WE Heiniger Limited, a Swiss company of Industrieweg 8, CH-3360 Herzogenbuchsee, Switzerland hereby declare the invention, for which I/We pray that a patent may be granted to me/us, and the method by which it is to be performed to be particularly described in and by the following statement: 1 To be followed by Page 1A 1A > "Shearing Comb" Field of the invention INTELLECTUAL PROPERTY OFFICE OF N.Z. \ 6 NOV 2001 RECEIVED The present invention relates to a shearing comb. More particularly, the shearing comb of the present invention is intended for use with a shearing hand 5 piece and cutter, for shearing sheep or other animals.

Background Art Shearing hand pieces typically utilise a comb that is releasably but rigidly attached to the hand piece, and a cutter arranged to reciprocate across a top surface of the comb. The comb and cutter are both subject to wear during use 10 and are generally periodically resharpened.

The comb is traditionally machined to provide a plurality of teeth therein and produces a broad shallow groove in the bottom surface of the comb between adjacent teeth. A second machining step is then required to provide an additional, steeper groove within the groove first mentioned, and to thereby 15 define a gullet between adjacent teeth. This method of manufacture is consequently time consuming and expensive.

Presently, shearing combs have a gullet angle, being that angle defined by the steeper groove between the teeth and the fiat plane of the top surface of the comb, of between about 20° and 40°. This provides a cutting angle of less than 20 90°. This is similarly the case along the majority of the length of each of the teeth of the comb.

In a new shearing comb of the prior art, the teeth thereof are shorter and are wider at a given distance from a ball or tip thereof than when the comb has been ground down, or sharpened, during use. This configuration when new is 25 provided to give the teeth sufficient strength to allow wool to be cut against it when ground down and the aim is to prevent the ground down teeth from springing or being disfigured during use. As a consequence of the angle of the gullet it is necessary to make the teeth shorter and wider at a given distance from the tip when new so that they do not become too long and narrow during use.

Importantly, a shearing comb is Known to be easier to use once ground down to an extent. This is as a result of the consequently thinner tooth width being able 5 to enter the wool of the sheep more easily than a wider, newer tooth A ground down comb tooth is also longer than a new tooth, given that the length of the gullet shortens with grinding whilst the tooth tip does not, and this provides the tooth with optimum flex and movement at its tip. This allows a vibration effect to occur, this acting such that the tooth tip vibrates between the wool follicles, 10 thereby enhancing the entry of the teeth into the wool It is one object of the shearing comb of the present invention to overcome substantially the abovementioned problems of the prior art and to provide a shearing comb that performs as a ground down shearing comb when new.

Throughout this specification, unless the context requires otherwise, the word 15 "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Disclosure of the Invention In accordance with the present invention there is provided a shearing comb 20 comprising a comb body and a plurality of teeth formed integrally therewith and projecting forwardly therefrom, the comb having top and bottom surfaces, the comb further having at least a first groove formed therein between adjacent teeth, the first groove defining a gullet, the angle of the gullet relative to the top surface of the comb being substantially 90°, whereby grinding of the top surface 25 to sharpen the comb does not substantially affect the length of the teeth.

Preferably, a second groove is provided in the bottom surface between adjacent teeth Still preferably, a cutting angle defined by the gullet and at least a portion of the length of the teeth and the top surface of the comb is substantially 90°, whereby the cutting angle remains at substantially 90° and the tooth width remains substantially the same, even after wear and/or grinding of the top surface of the 5 comb.

In accordance with the present invention there is further provided a method for manufacturing a shearing comb comprising a comb body and a plurality of teeth formed integrally therewith and projecting forwardly therefrom, the comb having top and bottom surfaces, the bottom surface having at least a first groove formed 10 therein between adjacent teeth and thereby defining a gullet, the angle of the gullet relative to the top surface of the comb being substantially 90°, the method comprising at least the step of forming the shearing comb from a sheet and thereby forming at least the substantially 90° gullet.

Preferably, a further step of forming a second groove, shallower than the first 15 groove, in the bottom surface between adjacent teeth is provided.

Still preferably, the further step of forming the second groove is conducted prior to the formation of the substantially 90° gullet.

Still further preferably, a cutting angle defined by the gullet and at least a portion of the length of the teeth and the top surface of the comb is substantially 90°, 20 whereby the cutting angle remains at substantially 90° and the tooth width remains substantially the same at a given point from the tip of the tooth, even after wear and/or grinding of the top surface of the comb- Brief Description of the Drawings The shearing comb of the present 25 example only, with reference to one drawings, in which:- invention will now be described, by way of embodiment thereof and the accompanying Figure 1 is a bottom plan view of a shearing comb according to the prior art, showing first and second grooves formed therein between adjacent teeth, the first groove forming a gullet between adjacent teeth; Figure 2 is a cross-sectional view along line AA of Figure 1; Figure 3 is a lower perspective view of a shearing comb in accordance with the present invention; Figure 4 is a bottom plan view of the shearing comb of Figure 3; Figure 5 is a cross-sectional view along line BB of Figure 4; Figure 6 is a front view of the shearing comb of Figure 3; Figure 7 is a top plan view of the shearing comb of Figure 3; Figure 8 is a rear view of the shearing comb of Figure 3; and Figure 9 is a schematic representation of the profile of a single tooth of the shearing comb of Figure 3, showing the profile of the single groove forming each tooth and the substantially 90° cutting angle formed by the cutting face of the tooth and the upper surface of the comb.

Best Mode(s) for Carrying Out the Invention In Figures 1 and 2 there is shown a shearing comb 10 in accordance with the prior art, the shearing comb 10 comprising a comb body 12 and a plurality of teeth 14 formed integrally therewith and projecting forwardly therefrom. The outermost teeth 14 are referred to respectively as the top-rider 16 and the bottom-rider 18. The comb body 12 has a pair of screw slots 20 provided therein to aid location in known manner on a shearing handpiece (not shown) In addition, there are provided a pair of positioning and pendulum holes 22 in the comb body 12 to facilitate location and attachment of the shearing comb 10 to a pendulum (not shown) during the grinding or sharpening of the comb 10.

The shearing comb 10 further has a bottom surface 24, being the surface that in use is in contact with the animal, for example, a sheep, being shorn. A steep or first groove 26 is formed in the comb body 12 between adjacent teeth 14 and defines the gullet 28. A shallow or second groove 30 is also formed within the comb body 12 between adjacent teeth 14 and extending therealong. The second groove 30 forms, in conjunction with the bottom surface 24, a white line 32 along a bottom surface of each tooth 14.

The angle of the first groove 26 with respect to an upper surface 44 of the shearing comb 10 is typically between about 20° to 40° at the gullet 28, best seen in Figure 2 Similarly, the teeth 14 generally broaden from the white line 32 at their bottom surface progressively towards their top surface, thereby providing a cutting angle that is less than 90°. The cutting angle is defined as that angle described by the steep or first groove 26 as it extends along the length of each tooth 14 and its intersection with the upper surface of the shearing comb 10.

In Figures 3 to 9 there is shown a shearing comb 40 in accordance with one embodiment of the present invention, the shearing comb 40 being in many respects similar to the shearing comb 10, like numerals denoting like parts.

The comb body 12 of the shearing comb 40 has substantially the same shallow or second groove 30 provided therein between adjacent teeth The first groove 26 of the shearing comb 40 defines a gullet 28 comprising a cutting face 42 which is at a substantially 90° angle to a top surface 44 of the shearing comb 40. The cutting face 42 extends from the gullet 28 along the length of each tooth 14, 25 as is best seen in Figure 9. Moving from the gullet 28 towards a ball or tip 46 of the tooth 14, the cutting edge 42 remains at a substantially 90° angle to the , upper surface 44 of the shearing comb 40.

In use, unlike the shearing comb 10 of the prior art, the shearing comb 40 of the present invention, both when new and ground down, provides a tooth width that avoids springing or being disfigured during use, but provides the desired ease of entry to the wool Further, the length of the tooth 14 from tip 46 to gullet 28 is longer when new than teeth of prior art shearing combs. This provides the teeth 14 with the desired degree of flex and movement at their tip 46 from new. This is 5 to be contrasted with prior art combs in which a period of wear is generally required before the desired degree of flex and movement is achieved. That is, it is only after a certain period of wear that the width and length of the teeth 14 of such combs are at an optimum.

The substantially 90° gullet 28 provided by the first groove 26 allows the shearing 10 comb 40 to be ground down without any effective alteration in the width of the teeth 14 at a point relative to the tips 46 thereof Further, the cutting angle during the life of the shearing comb 40 is maintained at substantially 90°.

It is envisaged that, due to the substantially 90° nature of the gullet and cutting angle, the shearing comb 40 may be manufactured in large part in a single 15 economical process. This process is envisaged to at least provide an efficient mechanism to produce the substantially 90° gullet 28 and cutting face 42 in the shearing comb 40.

Modifications and variations such as would be apparent to a skilled addressee are considered to fall within the scope of the present invention

Claims

The Claims defining the invention are as follows:

1 A shearing comb comprising a comb body and a plurality of teeth formed integrally therewith and projecting forwardly therefrom, the comb having top and bottom surfaces, the comb further having at least a first groove formed therein between adjacent teeth, the first groove defining a gullet, the angle of the gullet relative to the top surface of the comb being substantially 90°, whereby grinding of the top surface to sharpen the comb does not substantially affect the angle of the gullet with respect thereto.

2. A shearing comb according to claim 1, wherein a second groove is provided in the bottom surface between adjacent teeth.

3. A shearing comb according to claim 1 or 2, wherein a cutting angle defined by the gullet and at least a portion of the length of the teeth and the top surface of the comb is substantially 90°, whereby the cutting angle remains at substantially 90° and the tooth width remains substantially the same, even after wear and/or grinding of the top surface of the comb

4 A method for manufacturing a shearing comb comprising a comb body and a plurality of teeth formed integrally therewith and projecting forwardly therefrom, the comb having top and bottom surfaces, the bottom surface having at least a first groove formed therein between adjacent teeth and thereby defining a gullet, the angle of the gullet relative to the top surface of the comb being substantially 90°, the method comprising at least the step of forming the shearing comb from a sheet and thereby forming at least the substantially 90° gullet.

5 A method according to claim 4, wherein a further step of forming a second groove, shallower than the first groove, in the bottom surface between adjacent teeth is provided. -8 -

6. A method according to claim 4 or 5, wherein the further step of forming the second groove is conducted prior to the formation of the substantially 90" gullet.

7. A method according to claim 4, 5 or 6, wherein a cutting angle defined by 5 the gullet and at least a portion of the length of the teeth and the top surface of the comb is substantially 90°, whereby the cutting angle remains at substantially 90° and the tooth width remains substantially the same at a given point from the tip of the tooth, even after wear and/or grinding of the top surface of the comb. 10 8 A shearing comb substantially as hereinbefore described with reference to Figures 3 to 9. & WELLS