AU696787B2

AU696787B2 - Improved shearing combs

Info

Publication number: AU696787B2
Application number: AU11567/95A
Authority: AU
Inventors: Samson Te Whata
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-02-04
Filing date: 1995-02-02
Publication date: 1998-09-17
Anticipated expiration: 2015-02-02
Also published as: AU1156795A

Description

1"Mml t noaUuaikon 3 2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged:

D

s s e Invention Title: IMPROVED SHEARING COMBS The following statement is a full description of this invention, including the best method of performing it known to us:- I I IMPROVED SHEARING COMBS Technical Field The present invention relates to combs for shearing machines for shearing sheep or the like, in which a toothed cutter is oscillated in contact with a comb.

Background Art Shearing machines of the type referred to above are widely used to perform the task of shearing. A variety of comb designs have been proposed over the years, and various sizes and styles are commercially available.

1 0 Australian patent No. 261814 to R A Lister Company Limited discloses a comb with teeth having a curved shearer's bevel with a concave face beneath, and a substantially straight bend across the ends of the teeth. Australian patent i application No. 162/26 by F G Bristow discloses a similar arrangement, with a convex bend across the teeth. Australia patent No. 562878 to R A Lister Farm 1 5 Equipment Limited discloses again a similar arrangement, with a straight bend but for one tooth at either end.

A key performance characteristic required by a comb is the ability to readily and smoothly penetrate the fibre on an animal, yet allow the skin of the animal to pass under the comb during shearing.

It is an object of the present invention to provide an improved comb, and set of combs, with improved capacity to penetrate the fibres and ease of penetration without damaging the animal's skin.

Summary of Invention It is has been determined by the inventor that the use of a flat shearer' s bevel, and a relatively small radius tip on the comb teeth, provides improved performance in use. Additionally, it has been recognised that the appropriate comb varies somewhat in its dimensions depending upon the condition of the fibre and the skin of the sheep. The appropriate comb will, in general terms, haive a smaller tip radius, smaller bevel angle, and smaller bust as the condition of the wool declines through free combing through medium combing and tight combing to doggy combing, and as the skin varies from soft to hard.

According to one aspect of the present invention provides a sheep lm shearing comb, characterised in that the shearer's bevel is substantially flat, and the radius at the tip of the teeth is relatively small.

Preferably, the tips of the teeth of the comb follow a curve which is substantially concave.

Preferably the tip radius is less than 0.5 mm, most preferably in the range of about 0.15 mm to 0.30 mm.

Preferably the angle of the bevel to the back face of the comb is less that 650, most preferably 330 to 550.

According to another aspect the present invention comprises a set of combs adapted for use in a variety of conditions, wherein a first comb adapted for free combing and soft skin has a first bevel angle and a first tip radius; a second comb adapted for medium combing and medium skin has said first bevel i angle and a second tip radius less than said first tip radius, a third comb adapted for tight combing has a second bevel angle smaller than said first bevel angle oooo 15 and a third tip radius smaller than said second tip radius, and a fourth comb .oo..i adapted for doggy combing has a third bevel angle smaller than said second bevel angle and said third tip radius.

A further aspect of the present invention provides a set of sheep shearing combs adapted for use under various fibre and skin conditions, wherein as the condition of the fibre changes from free combing through to doggy combing, the respective combs decrease in tip radius.

A further aspect of the present invention provides a set of sheep shearing combs adapted for use under various fibre and skin conditions, wherein as the condition of the fibre changes from free combing through to doggy combing, the bevel angle decreases.

Preferably, the bust width also decreases as the fibre changes from free combing through to doggy combing.

A further aspect of the present invention relates to the shape of the teeth of the comb, in the sense of the plan view of the teeth. This aspect of the invention is predicated on the discovery that one of the critical factors in allowing smooth penetration is the angle at the top of the glider teeth, particularly the trailing edge teeth 1, 2, presented to incoming fibre. This angle must guide and I

I

3 gather the fibre into the space between the teeth. If the angle presented is too great, the fibre does not gather as well. Conventional wider combs, with glider teeth, are widely bent outwards at the critical point of the tooth. According to this aspect of the invention, the tooth commences bending outwards closer to the base of the tooth, so that the curve at the upper end is reduced.

According to this aspect of the present invention there is provided an improved shearing comb of the type comprising a plurality of substantially coplanar teeth, the tips of said teeth describing a concave curve, at least the two teeth at the end opposite to normal entry into the fibre having an outward curve, 1 0 characterised in that said teeth have a substantially smooth curve on the inward facing surface, said curve commencing at or near the base of the teeth.

Description of Drawings An illustrative embodiment of the present invention will now be described with reference to the accompanying figures, in which: Figures 1 to 4 are plan views showing the general arrangement of teeth according to preferred implementations; Figure 5 illustrates the bust, bevel and tip radius of a tooth as a notional side view; and Figure 6 illustrates bust, bevel and tip radius of a glider tooth as a notional 20 side view.

S" Description of Embodiment Referring to figure 1, a conventional shearing comb generally has 13 teeth. The outer teeth, 1 and 13, are referred to as gliders.

Figure 5 illustrates a side view of an illustrative central tooth, for example tooth 8. It will be appreciated that overall length will vary. The teeth have a rear surface 21, a tip 22 and a shearer's bevel 23. The teeth according to the present invention have a relatively small tip radius, for example 0.15 to 0.30 mm, and in any case less than 0.50 mm. Additionally, bevel 23 is substantially flat, in contrast to conventional combs where it is curved. These features give rise to a significant improvement in performance. Additionally, it is preferred that the bust be varied for various conditions as outlined below.

The bust 24 can also be seen from the sectional view. This is the width of the tooth at the tip. According to conditions, bust width may be varied, for example from 0.4 to 0.6 mm.

Figure 6 llustrates a similar view to figure 5, in relation to glider teeth, 1 ana 13. The glider teeth have an indent on the back face, as is known for other glider teeth. The bevel, again, varies for different conditions of fibre and skin.

The bust width is illustratively 0.9 mm.

The for various following table illustrates preferred bust, tip radius and bevel angles conditions: Bend 94 mm 93 mm 91 mm 86 mm Bevel Tip Bust short (55) short short short r o e r r short short short short med med med med long long long long (55) large (0.30) large large large( med (0.25) med med med small (0.15) small small small small (0.15) small small" small thick (0.60) thick( thick( thick( med (0.50) med med( med(" med (0.50) med( med med(

FREE

COMBING

MED.

COMBING

TIGHT

COMBING

SOFT

SKIN

MED.

SKIN

HARD

SKIN

(33) (0.40)

DOGGY

COMBING

HARD

SKIN

It will be understood that while the best selection of all these parameters is preferred a beneficial effect according to obtained if only one or two are varied. The the present invention will be inventor has appreciated the significance of varying these parameters, in order to accommodate various conditions, and this concept of selection is an aspect of the present invention.

As can be seen from figures 1 to 4, other dimensions and relative dimensions should be selected so as to provide the best effect. These vary in figures 1 to 4, as comb width changes.

Teeth 1,2 on each comb are preferably carefully shaped, in the plan view, substantially as shown. As discussed above, the precise shaping of the teeth is critical in achieving optimum performance. The gliders are principally provided so as to perform a gathering function. As such, the angle presented by the inward facing surfaces of the teeth, particularly the 1 and 2 teeth, is critical to smooth performance. It is important that the cross sectional width between the teeth presented to the fibres being gathered is not too large, or it is difficult to force the fibres smoothly through the teeth. Moreover, any abrupt change in the width of the channel between the teeth will interfere with the smooth gathering of the wool. However, the teeth, in particular the tips, need to diverge outwards to provide the desired concave 21. The solution according to the present invention 15 is to begin the outward curve at a point closer to the base than is conventional in combs of this general type, preferably at least half of the distance from the tip to the base, and most preferably from at or near the base. It is particularly the inside surface of the glider teeth, which in use is the contacting surface, which must have such a curve. Similarly, it is important that the 13 tooth, the entry tooth, 20 be not too far bent, as is the case in some conventional combs. This is the entry tooth, so that accuracy of fibre removal is critically dependant upon it entering the animal's coat cleanly and accurately. Once again, the technique for providing the required outward position at the tip is to begin the outward curve at a lower point on the tooth.

In the case of both the 1 and 2 teeth, and on the 13 tooth, it is preferred that the curve be smooth from the base, and not present obvious discontinuities in the slope. A clear change of direction tends to create a bottleneck for the fibre being gathered, impeding the smooth working of the comb.

It is to be understood that the above describes only preferred embodiments of the invention and that variations to the embodiments are possible within the-spirit and scope of the invention as defined by the following claims.

Claims

1. A sheep shearing comb, characterised in that most of the teeth of the comb have a shearers bevel which is substantially flat and have a reduced tip radius relative to that of a conventional curved bevel comb.

2. A comb according to claim 1, wherein the tips of the teeth of the comb follow a curve which is substantially concave.

3. A comb according to claim 2, wherein the tip radius is less than 0.5 mm.

4. A comb according to claim 3 wherein the tip radius ranges from 0.15mm to 0.3 mm.

A comb according to any one of the preceding claims wherein the angle of the bevel to the back face of the comb is less than o

6. A comb according to claim 5 wherein the angle is 330 to 550

7. A set of sheep shearing combs wherein at least some of the combs are according to claim 1, adapted for use in a variety of conditions, said set comprising 2 or more combs selected from the set comprising first, second, third and fourth combs as defined below; wherein the first comb is adapted for free combing and soft skin and has a first bevel angle and a first tip radius; said second comb is adapted for medium combing and medium skin and i has said first bevel angle and a second tip radius lessthan said first tip radius; said third comb is adapted for tight combing and has a second bevel angle smaller than said first bevel angle and a third tip radius smaller than said second tip radius; and said fourth comb is adapted for doggy combing and has a third bevel angle smaller than said second bevel angle and has said third tip radius, c

8. A set of sheep shearing combs wherein at least somrne of the combs are according to claim 1, adapted for use under various fibre and skin conditions, wherein as the condition of the fibre changes from free combing through to doggy combing, the respective combs decrease in tip radius.

9. A set ui sheep shearing combs wherein at least some of the according to claim 1, adapted for use under various fibre and skin wherein as the condition of the fibre changes from free combing doggy combing, the shearer's bevel angle decreases.

A set of sheep shearing combs wherein at least some of the according to claim 1, adapted for use under various fibre and skin wherein as the condition of the fibre changes from free combing doggy combing, the bust width decreases. combs are conditions, through to combs are conditions, through to a s o r P s

11. A set of sheep shearing combs according to claim 10 wherein the bust width ranges from 0.4mm to 0.6mm.

12. A sheep shearing comb according to claim 1 comprising a plurality of substantially co-planar teeth, the tips of said teeth describing a concave curve, at least the two teeth at the end opposite to normal entry into the fibre having an outward curve, characterised in that said at least two teeth have a substantially smooth curve on the inward facing surface, said curve commencing between the middle of the tooth and the base of the tooth.

13. A comb according to claim 12, wherein the tooth at the end of normal entry into the fibre is curved outward, said curve commencing between the middle of the tooth and the base, said curve being substantially smooth. DATED this 30 day of April 1997 SAMSON TE WHATA WATERMARK PATENT TRADEMARK ATTORNEYS LEVEL 4, AMORY GARDENS 2 CAVILL AVENUE ASHFIELD N.S.W. 2131 AUSTRALIA PNF:MP:RM DOC041 PM3719.WPC ABSTRACT A shearing comb adapted to provide improved ease of fibre entry. The comb includes teeth having a flat bevel 23, and a small tip radius 22. Preferably, the size of the tip radius, and the bevel angle, are selected to have different values when the comb is adapted for use in different conditions. A preferred curve for the glider teeth, and concave shape, are described. *S*