WO1989002351A1

WO1989002351A1 - Shearing comb

Info

Publication number: WO1989002351A1
Application number: PCT/AU1988/000295
Authority: WO
Inventors: Guy Edmond Waters
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-09-10
Filing date: 1988-08-10
Publication date: 1989-03-23
Anticipated expiration: 1990-03-10

Abstract

A shearing comb comprises a body portion having a recess (20) for receiving an insert (22). The body portion has teeth (14) and the insert (22) also has teeth (28, 29) on each of its sides. Each set of teeth (28, 29) provides two cutting portions (22a, 22a', 22b, 22b') which enable the insert (22) to be inverted or turned about side for side so that one of the cutting portions (22a, 22a', 22b, 22b') together with an upper cutting comb (51) can be used to cut fleece of a sheep. The insert (22) is coated with titanium nitride or titanium aluminium nitride and the body portion is provided with bores (50) for receiving screws for retaining the insert (22) in the recess (20).

Description

SHEARING COMB This invention relates to a shearing comb for shearing sheep.

Conventional shearing combs require continual re-sharpening and therefore are required to be maintained regularly. One of the problems with the need to continually re-sharpen, apart from the cost and inconvenience, is that the shearing comb is provided with a sharp tip in view of the grinding action required to sharpen the comb and the sharp tip can cause injury to a sheep by gripping and cutting the skin of the sheep as the comb is moved through the sheep's fleece.

The object of this invention is to provide a shearing comb, which requires less maintenance or at least is less difficult to maintain than conventional combs.

The present invention may be said to reside in a shearing comb, said shearing comb having a base comb portion, an upper cutting comb having a plurality of teeth and a removable cutting insert having a plurality of teeth located between said upper comb and base comb, said upper cutting comb being arranged for reciprocating movement relative to said cutting insert such that the fleece can be cut by the reciprocating movement of the upper cutting comb relative to the insert.

Since the comb of this invention includes an insert which is removable and which provides a cutting action together with the upper comb, the comb of this invention requires less maintenance since cutting inserts can easily be interchanged and re-sharpened themselves at a later date.

Preferably the base comb is provided with a recess portion and the insert is adapted to be received in said recess portion. Preferably the insert has two cutting surfaces at each end so that it can be inverted and relocated in the shearing comb and also turned about side for side and relocated to thereby provide four cutting portions. Preferably the recess extends from a body portion of the base comb to a point inwardly of the end of teeth of the base comb. Preferably the recess and the cutting comb have matching edges to securely locate teeth of the insert relative to teeth of the base comb. Preferably the comb has retaining means for retaining the insert in the recess.

A significant advantage of one embodiment of this invention is that since cutting takes place between the cutting surfaces of the insert and the upper cutting comb, the teeth of the base comb are not required to be sharpened and therefore they can be formed with ends suitably shaped to easily pass through the fleece of a sheep so that when the comb is forced through a sheep's fleece it is less susceptible to injurying the sheep as compared with conventional combs which have pointed teeth in view of the need to sharpen the teeth of the base comb. Preferably the insert is coated with a hard coating such as a titanium nitride coating or a titanium aluminium nitride coating which maintains the cutting surface of the insert. The provision of titanium nitride or titanium aluminium nitride coatings on the insert significantly reduces wear of those components and therefore the components last considerably longer without the need of replacement or resharpening.

The invention also provides a cutting insert for a shearing comb, said cutting insert having a middle body portion and two sets of teeth extending outwardly from said body portion with one set of teeth being on each side of the body portion, said cutting insert adapted to be located between a base comb and an upper cutting comb of the shearing comb. A preferred embodiment of the invention will be described with reference to the accompanying drawings in which;

Figure 1 is a plan view of a base comb used in the preferred embodiment of the invention, Figure 2 is a detailed view of an end of a tooth of the base comb of Figure 1,

Figure 3 is a side view of a comb according to the preferred embodiment of the invention, Figure 4 is a detail view of part of a comb embodying the invention and,

Figure 5 is a view of an insert used in the preferred embodiment of the invention.

With reference to the accompanying drawings, a shearing comb is shown which comprises a base comb portion 10 (shown in Figure 1) which comprises a body portion 12 which has a plurality of teeth 14 extending therefrom. As is best seen in figure 3 the base comb 10 is provided with a recess 20. The recess extends from the body portion 12 to a point slightly inwardly of the end of the teeth 14.

The recess 20 is adapted to receive a cutting insert 22 which is shown in figure 5. The cutting insert 22 is configured so that it matches the recess 20 in the base comb 10 and generally has a middle body portion 26 and a plurality of teeth 28 and 29 at each side of the body portion 26. A wall 30 of the recess 20 on each of the teeth 14 matches the end 31 of the teeth 28 and 29 of the insert 22. As is best shown in Figure 3, the insert 22 is the same thickness as the recess 20. The insert 22 can be removed and inverted as well as turned about side .for side and re-located in place by engagement of the walls 30 and ends 31. This enables the insert 22 to be provided with four cutting surfaces 22A, 22A" and 22B and 22B' and for the insert to be inverted or turned about when one surface becomes blunt so that another cutting surface can be used. As is clearly seen in Figures 1, 3 and 4, a rear portion 12A of body 12 of the base comb 10 is provided with a retaining device for retaining the cutting insert in the recess 20. The retaining device comprises a pair of bores 50 which extend through the rear portion 12A and communicate with the recess 20. The bores 50 have enlarged head portions 52 for receiving a screw 54 which is shown in Figure 4. The bores 50 are screw threaded to match the screw threads on the screw 54 so that the screws 54 can be screwed into the bores 50 so that ends 55 of the screws 54 will engage the ends 31 of two of the teeth 28 or 29 of the insert 22 which align with the bores 54. The screws 54 push the insert 22 so that the ends 31 of the other set of teeth 28 or 29 on the insert 22 securely engage end walls 30 of the teeth 14. A firm but releasable adhesive, such as a lock-tight adhesive, can be located between the wall 30 and the end 31 of the finger 28 or 29 before the screw 54 is tightened so that the securement of the insert 22 in the recess 20 is assured. When it is desired to remove the insert 22 for relocation or sharpening, the adhesive can simply be broken after release of the screws 54 to enable the insert 22 to be removed.

An upper cutting comb 51 which is shown in figure 3 is located on the insert 22 and is held in place by a conventional "chicken foot" device 60. The upper comb 51 is adapted to reciprocate relative to the insert 22 which is fixed relative to the base comb 10 in the conventional manner and by conventional means (not shown) to provide a cutting action between cutting surfaces on the teeth 28 or 29 of the insert 22 and on the teeth ,of the upper comb 51. The base comb 10 is preferably formed from high tensile mould steel, the insert 22 and 'the upper comb 51 are preferably formed from tool steel. Preferably the insert 22 is provided with a hard coating such as a titanium nitride coating or a titanium aluminium nitride coating to decrease wear of the cutting surfaces on the insert 22 to thereby greatly reduce maintenance. When cutting surfaces on the insert 22 and upper comb 51 are worn, the upper comb 51 and the insert 22 are removed. The insert 22 may be inverted or turned about to expose another cutting surface and the upper comb 52 may be resharpened or replaced. If necessary, the insert 22 can also be replaced an the used insert resharpened and recoated.

Unlike conventional combs, the base comb does not form part of the cutting operation and therefore it need not be resharpened. Since the base comb need not be resharpened it can be made with more tensile strength through being at a lower hardness factor and it can be provided with a permanent shaped tip at each finger 14 (as is best seen in Figures 2 and 3). Figures 2 and 3 show two different types of tips which may be employed. Since the tips may be permanently formed they can be shaped so as to suit the type of fleece with which they are to be used. For example, in sheep having a tight fleece the tip can be more pointed as in Figure 2 so that it can easily pass through the tight fleece. If the fleece is somewhat more loose the tip can be more rounded or squared as shown in Figure 3, to reduce the likelihood of cutting the sheep as the comb passes through the sheep's fleece.

The provision of a removable and replaceable insert which can be provided with two cutting surfaces greatly reduces the amount of maintenance which is required to maintain a shearing comb and also reduces downtime of a shearing comb since the insert can be easily inverted or replaced but the comb can continue to be used. Furthermore, the provision of a hard coating on the insert also greatly .contributes to the cutting life of the insert and further reduces the need for maintenance and in particular resharpening.

Since modification within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A shearing comb, said shearing comb having a base comb portion, an upper cutting comb having a plurality of teeth and a removable cutting insert having a plurality of teeth located between said upper comb and base comb, said upper cutting comb being arranged for reciprocating movement relative to said cutting insert such that the fleece can be cut by the reciprocating movement of the upper cutting comb relative to the insert.

2. The shearing comb of Claim 1, wherein the base comb is provided with a recess portion and the insert is adapted to be received in said recess portion.

3. The shearing comb of Claim 1 or Claim 2, wherein the insert has two cutting surfaces at each end so that it can be inverted and relocated in the shearing comb and also turned about side for side and relocated to thereby provide four cutting portions.

4. The shearing comb of Claim 2, wherein the recess extends from a body portion of the base comb to a point inwardly of the end of teeth of the base comb, the recess and the cutting comb having matching edges to securely locate teeth of the insert relative to teeth of the base comb.

5. The shearing comb of Claim 2, wherein the comb has retaining means for retaining the insert in the recess.

6. The shearing comb of Claim 5, wherein said retaining means comprises at least one bore in said base comb which communicates with said recess, said bore being screw threaded for receiving a screw which can be screwed into said bore so that an end of said screw engages the insert when located in the recess to retain the insert in the recess.

7. The shearing comb of Claim 1, wherein the insert is coated with a hard coating.

8. The shearing comb of Claim 7, wherein the coating is a titanium nitride coating or a titanium aluminium nitride coating.

9. A cutting insert for a shearing comb, said cutting insert having a middle body portion and two sets of teeth extending outwardly from said body portion with one set of teeth being on each side of the body portion, said cutting insert adapted to be located between a base comb and an upper cutting comb of the shearing comb.

10. A cutting insert according to Claim 9, wherein the insert is coated with a hard coating.