AU2002301690B2

AU2002301690B2 - Shearing Cutter

Info

Publication number: AU2002301690B2
Application number: AU2002301690A
Authority: AU
Inventors: Philip David Jones
Original assignee: Heiniger Ltd
Current assignee: Heiniger Ltd
Priority date: 2001-12-11
Filing date: 2002-10-30
Publication date: 2006-09-21
Anticipated expiration: 2022-10-30

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventor Heiniger Limited Philip David JONES WRAY ASSOCIATES Level 4, The Quadrant 1 William Street Perth, WA 6000 Address for service is: Attorney code: WR Invention Title: "Shearing Cutter" Details of Associated Provisional Application No(s): PR9423 The following statement is a full description of this invention, including the best method of performing it known to me:- "Shearing Cutter" Field of the Invention The present invention relates to a shearing cutter. More particularly, the shearing cutter of the present invention is intended for use in the shearing of sheep and similar animals.

Background Art At present the shearing, crutching and trimming of animal wool and hair is most commonly achieved using either an electric or externally driven shearing handpiece utilising both a comb and cutter to cut hair or wool through which the comb and cutter are pushed. The comb is generally fixed relative to the shearing handpiece whilst the cutter passes over a upper surface of the comb in a precipitating fashion. Both the cutter and comb are provided with a plurality of teeth that perform the cutting action.

The cutters typically utilised in the shearing of sheep generally comprise four teeth, adjacent teeth defining therebetween a gullet. The outer edges of the cutter have provided therein a corner. The corner is defined as the outer edges of the cutter diverge from a base of the cutter and then again converge to form the outer teeth of the cutter. The cutter corners are typically provided in a position "forward" relative to an arc drawn through the gullets. Also, the outer cutting edge of the outer teeth is typically substantially the same length as the remaining cutting edges.

The forward positioning of the corners of present cutters can result in the "locking-up" of the cutter and comb of a shearing handpiece during use. These "lock-ups" are caused by the corners of the cutters catching in the gullets defined between the adjacent teeth of the comb. As a cutter wears during its lifespan the tips or points of the cutter teeth effectively retreat towards the drive pin-holes of the cutter. A user will then, in an effort to prevent having to push the leading edges of the comb teeth through the wool being shorn, move the comb rearwardly on the handpiece by adjusting the comb position under the mounting screws on the shearing handpiece. As this moves the gullets of the adjacent teeth of the comb rearwardly with respect to the cutter, this tends to accentuate lock-ups between the corners of the cutter and the comb teeth gullets.

As a shearing comb is ground the gullets defined by adjacent teeth will also retreat towards the base of the comb, even without the user adjusting the relative position of the comb and handpiece. This again tends to accentuate lock-ups between the corners of the cutter and the comb teeth gullets.

Further, the cutters produced by some manufacturers incorporate a feature referred to as an "undercut crown" which introduces additional points or corners into the gullets of the cutter, these points or edges similarly being prone to catching the gullets of the adjacent comb teeth during use and thereby causing lock-ups.

The shearing cutter of the present invention has as one object thereof to overcome the abovementioned problems associated with the prior art, or to at least provide a useful alternative thereto.

The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia as at the priority date of the application.

Throughout the specification, unless the context requires otherwise, the word "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 cutter for use in conjunction with a shearing comb, the shearing cutter comprising a base on which a plurality of teeth are provided, adjacent teeth defining therebetween a gullet, an outer side edge of the base and outermost teeth defining a corner at each outer edge thereof, the corners being located rearwardly of an arc described by the gullets, whereby in use the corners of the cutter will not tend to pass directly over gullets provided in the comb, thereby minimising the chance of the cutter and comb locking-up.

Preferably, the radius of each corner of the cutter is greater than 0.5 mm.

Still preferably, the radius of the cutter corners is about or greater than 3 mm.

In accordance with the present invention there is further provided a shearing cutter for use in conjunction with a shearing comb, the shearing cutter comprising a base on which a plurality of teeth are provided, adjacent teeth defining therebetween a gullet, an outer side edge of the base and an outer cutting edge of the outermost teeth defining a corner at each outer edge thereof, the outer cutting edges of the outer teeth being substantially longer than the remaining cutting edges of each of the teeth, whereby in use the corners of the cutter will not tend to pass directly over gullets provided in the comb, thereby minimising the chance of the cutter and comb locking-up.

Preferably, the radius of each corner of the cutter is greater than 0.5 mm.

Brief Description of the Drawings The shearing cutter of the present invention will now be described, by way of example only, with reference to one embodiment thereof and the accompanying drawings, in which:- Figure 1 is a top plan view of a shearing cutter of the prior art; Figure 2 is a bottom plan view of the prior art shearing cutter of Figure 1; Figure 3 is an upper perspective view of a shearing cutter in accordance with the present invention; Figure 4 is a top plan view of the shearing cutter of Figure 3; Figure 5 is a top plan view of a prior art shearing cutter in use on a shearing comb and associated shearing handpiece, of which only a portion is shown, the prior art cutter being new; Figure 6 there is shown the prior art shearing cutter and shearing handpiece of Figure 5, the shearing cutter being worn and the comb being pulled back on the shearing handpiece; Figure 7 is a top plan view of the shearing cutter of Figure 3 in use on a comb and shearing handpiece, the shearing cutter being new; and Figure 8 is a top plan view of the shearing cutter, comb and hand piece configuration of Figure 7, the shearing cutter being worn and the comb being pulled back with respect to the shearing handpiece.

Best Mode(s) for Carrying Out the Invention In Figures 1 and 2 there is shown a shearing cutter 10 of the prior art. The shearing cutter 10, when viewed in plan view, comprises a base 12 and a plurality, for example four, forwardly projecting teeth 14. The adjacent teeth 14 each define therebetween a gullet 16. The outermost teeth 14a and 14b define an outer side edge 18, the forwardmost portion of which acts as an outer cutting edge. Each outer side edge 18 defines a corner 20 where that outer side edge 18 meets the base 12.

The base 12 is of generally arcuate form as can be seen by reference to Figures 1 and 2. Each outer side edge 18 diverges as it passes forwardly on the cutter to the corners 20, after which it converges to form each outer cutting edge and in turn, outermost teeth 14a and 14b. The gullets 16 generally describe an arc 22 which is generally consistent with the arcuate form of the base 12. The corners 20 generally are located forward of the arc 22 described by the gullets 16. Further, the outer cutting edges are substantially of the same length as the remaining cutting edges.

The shearing cutter 10 also has provided therein a pair of pendulum holes 24, a pair of safety pin-holes 26 and each tooth 14a and 14b has a drive pin-hole 28 provided therein.

In Figures 3 and 4 there is shown a shearing cutter 40 in accordance with the present invention. The shearing cutters 10 and 40 are substantially similar and like numerals denote like parts. However, as can be seen in Figure 4, an arc 42 described by the gullets 16 passes forwardly of the corners 20. As such, the corners 20 are located more towards the rear or base 12 of the cutter 40 than on the prior art cutter 10. The corners 20 of the shearing cutter 40 are provided at a radius of about 3 mm. This is a bigger or smoother radius than the corner 20 of the prior art cutter 10, generally provided with a radius of about 0.5 mm.

Further, the outer cutting edges of the shearing cutter 40 are substantially longer than the remaining cutting edges on the cutter In Figures 5 and 6 there is shown a shearing cutter 50 in accordance with the prior art in position on a shearing handpiece 52 shown in part and a comb 54.

The comb 54 is mounted to the comb bed 56 of the shearing handpiece 52 in known manner. The shearing cutter 50 is located on the comb 54 by chicken feet 58, again in known manner.

The shearing comb 50 of the prior art differs in one detail from the prior art shearing cutter 10 described hereinabove, being the presence of under-cut crowns 60 within the gullets 16. The under-cut crowns 60 are a feature of shearing cutters produced by some manufacturers. The prior art shearing cutters 10 and 50 are otherwise substantially identical, particularly with regard to the relative location of the corners 20, to the base 12.

The comb 54 is provided with a plurality of teeth 62. Between adjacent teeth 62 are defined gullets 64.

As can be seen in Figure 5, in which the comb 54 has not been drawn as far rearwardly as is possible on the comb bed 56, the under-cut crowns 60 pass over the gullets 64 of the comb teeth 62 and may become locked thereon as the cutter 50 reciprocates across the comb 54. In Figure 6 the comb 54 has been drawn further rearwardly on the comb bed 56, as would typically be done as the shearing cutter 50 wears and becomes thinner. In such an arrangement, it can be seen that not only might the under-cut crowns 60 engage and lock with the gullets 64, but the corners 20 of the shearing cutter 50 may also engage and lock with the gullets 64.

In Figures 7 and 8 there is shown the shearing cutter 40 of the present invention in the in-use positions corresponding to Figures 5 and 6. Again, Figure 7 shows the shearing cutter 40 in use when new and having the comb 54 positioned relatively forwardly on the comb bed 56 of the shearing handpiece 52. In Figure 8 the shearing cutter 40 is shown in a worn configuration with the comb 54 drawn relatively rearwardly on the comb bed 56.

In the arrangements of both Figures 7 and 8 it can be seen that the corners 20 of the shearing cutter 40 of the present invention do not pass over the gullets 64 defined by the comb teeth 62. This thereby minimises any chance of the shearing cutter 40 and the comb 54 locking-up during use, even when the shearing cutter 40 is worn and the comb 52 drawn to its most rearward position.

Further, the absence of under-cut crowns ensures that these will not engage with the gullets 64 of the comb 54 and thereby produce a lock-up.

In addition, the corners 20 of the prior art shearing cutter 50 generally have a sharper radius, being about 0.5 mm. When worn this corner 20 can produce a -8point which is highly conducive to lock-ups. The corners 20 of the shearing cutter 40 of the present invention are provided with a radius of about or greater than 3 mm which is generally consistent even when worn, thereby avoiding the production of a point at the corner 20 as is a feature of many prior art shearing cutters.

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

Claims

1. A shearing cutter for use in conjunction with a shearing comb, the shearing cutter comprising a base on which a plurality of teeth are provided, adjacent teeth defining therebetween a gullet, an outer side edge of the base and outermost teeth defining a corner at each outer edge thereof, the corners being located rearwardly of an arc described by the gullets, whereby in use the corners of the cutter will not tend to pass directly over gullets provided in the comb, thereby minimising the chance of the cutter and comb locking-up.

2. A shearing cutter according to claim 1, wherein the radius of each corner of the cutter is greater than 0.5 mm.

3. A shearing cutter according to claim 1 or 2, wherein the radius of the cutter corners is about or greater than 3 mm.

4. A shearing cutter for use in conjunction with a shearing comb, the shearing cutter comprising a base on which a plurality of teeth are provided, adjacent teeth defining therebetween a gullet, an outer side edge of the base and an outer cutting edge of the outermost teeth defining a corner at each outer edge thereof, the outer cutting edges of the outer teeth being substantially longer than the remaining cutting edges of each of the teeth, whereby in use the corners of the cutter will not tend to pass directly over gullets provided in the comb, thereby minimising the chance of the cutter and comb locking-up.

A shearing cutter according to claim 4, wherein the radius of each corner of the cutter is greater than 0.5 mm.

6. A shearing cutter according to claim 4 or 5, wherein the radius of the cutter corners is about or greater than 3 mm.

7. A shearing cutter substantially as hereinbefore described with reference to Figures 3, 4, 7 and

8. Dated this Thirtieth day of October 2002. Heiniger Limited Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant(s)