GB2236327A

GB2236327A - Plated finish for a shearing handpiece body

Info

Publication number: GB2236327A
Application number: GB9019886A
Authority: GB
Inventors: John Alun Harris Williams; Robert W Bayston
Original assignee: Lister Shearing Equipment Ltd
Current assignee: Lister Shearing Equipment Ltd
Priority date: 1989-09-13
Filing date: 1990-09-11
Publication date: 1991-04-03
Anticipated expiration: 2010-09-11
Also published as: GB9019886D0; GB2236327B

Abstract

The shearing handpiece body 10 is formed by a method which includes providing at least part of the body with a rough surface 2, providing the rough surface with a coating eg. electrophoretically applied paint and plating eg. by electroplating with nickel the coated area so as to cause at least some of the plating material to penetrate the coating and/or adhere to the coating thereby giving a speckled finish to the handpiece body. <IMAGE>

Description

A-SHEARING HANDPIECE BODY This invention relates to a shearing handpiece body and to a method of finishing a shearing handpiece/body.

It is known that sheep shearers are conscious of the appearance as well as the function of sheep shearing handpieces. Therefore, manufacturers of shearing handpieces have, over the years, produced various finishes not only to provide a pleasing appearance but also to give a good "feel". Previously we have utilised a nickel plated finish on a cast metal handpiece which has been grit blasted prior to plating. Whilst the nickel provides a very attractive all-over silver finish, it limits somewhat any desired variation in finish that can be achieved.

One object of the present invention is to provide a method of finishing which results in a variation from the basic silver finish whilst providing the surface characteristic necessary to give the shearer the required grip or feel.

According to the one aspect of the invention there is provided a method of finishing a body of a shearing handpiece comprising providing at least part of the handpiece body with a rough surface, providing the rough surface with a coating and plating the coated area so as to cause at least some of the plating material to penetrate the coating and/or to adhere to the coating thereby giving a finish to the handpiece body.

According to a second aspect of the invention there is provided a shearing handpiece body having a part formed with a rough surface, said rough surface having thereon a coating and said rough surface being plated, at least some of the plating material penetrating the coating.

By using a method according to the first aspect of the invention it is possible to achieve a pleasing finish of speckled appearance different from an all-over silver finish, the depth of thickness of the coating being selected so as to maintain the surface characteristic necessary for good grip. Also, grip is somewhat enhanced by the plating material which, preferably, takes on the form of globules or particles at least some of which stand proud of the coating surface.

The initial surface may be formed e.g., by a spheroidal graphite iron casting process and may be roughened e.g.

by sand or steel blasting to produce sharp protrusions.

The coating may be provided by an electrophoretic deposit such as paint. A suitable paint for that purpose is used in a process known as EPOSEAL (Trade mark) process. The process involves immersing a component in a solution through which an electric current is passed. A deposit of paint appears on the component which is then removed from the solution and heated e.g. by stoving to cure the paint deposit.

The finishing method preferably includes providing a smooth part of the handpiece body with a continuous plated finish. In such a case, the handpiece body may be provided with said coating on both the smooth and rough parts, the coating then being removed from the smooth part and both parts then being electroplated simultaneously whereby the electroplating material plates the smooth part as a continuous plated layer but forms the finish, preferably a speckled appearance, on the coated part.

The smooth part of the handpiece body is preferably a front end part which, in use, lies adjacent shearing blades carried by the handpiece.

The invention also includes a shearing handpiece body made by a method according to said first aspect of the invention or any of the consistory clauses related thereto.

A method and shearing handpiece body in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is an elevation of a sheep shear handpiece body having a finish produced by a method in accordance with the invention, Fig. 2 is a view to a larger scale of part of the body surface in circle II in Fig. 1, Fig. 3 is a cross-section of the part of the body shown in Fig. 2 on line III-III on Fig, 2 and drawn magnified, Fig. 4 is a magnified cross-section through part of a surface of the handpiece body prior to blasting, Fig. 5 is a magnified cross-section through part of the roughened surface of the handpiece body after blasting, and FIg. 6 is a magnified cross-section through an electroplated smooth front end of the body.

The handpiece in Fig. 1 includes a body 10 formed by spheroidal graphite iron casting. The casting step creates a slightly rough exterior surface 12 as shown in Fig. 4. The exterior surface 12 is subsequently further roughened to the form shown in Fig. 5 in which it has many sharp peaks 12a by blasting with e.g., sand or steel particles. The body 10 has a front end 13 which, after the moulding and blasting steps, is smoothed and polished.

The body 10 is then subjected to an electrophoretic process so that the entire surface of the body is coated with a thin layer 14 (e.g., around 14 to 20 microns) of electrophoretic paint such as that used in the aforesaid EPOSEAL process. The paint is cured by stoving or other heat treatment so that it tends to flow and thin out on peaks 12a and accumulate in valleys or crevices 12b. The paint is then removed from the polished front end 13 up to a transition line 15 between the polished surface and the rough exterior surface 12. It is envisaged that a coating other than that provided by an electrophoretic process may be used.

The body 10 is then subjected to an electroplating process e.g., nickel, chrome, zinc, copper etc. plating.

The plating forms a continuous finish 16 e.g., of around 10 to 15 microns thickness on the smooth from end 13 (Fig. 6) but deposits as a multiplicity of globules 17 on the coated part 12 of the body. Certain globules 17a (Fig. 3) penetrate the coating 14, particularly adjacent peaks 12a on the surface where the thickness of coating tends to be reduced. Other globules 17b adhere to the surface of coating 14 without penetrating the coating 14 or only partially penetrating the coating. A globule may form a pore in the coating through which it penetrates the coating, or may pass through an existing pore in the coating.

The resulting finish is extremely effective both from the point of view of appearance and utility. The selected colours of the electrophoretic paoint, e.g, black, and the electroplating material e.g., nickel, create a contrasting speckled finish which is very pleasing to the eye. Moreover at least some of the globules 17a, 17b of plates metal stand proud of the coating 14 and form an improved gripping surface for the hand of the user. Also, the globules tend to be rounded and so are extremely comfortable to the user's hand whilst providing a very positive grip. Furthermore the paint coating which accumlates in the crevices 126 in the roughened surface tends to prevent the crevices filling with foreign matter during use. Therefore, the peaks 12a have a comfortable feel in view of the rounded globules, the crevices, 12b are less likely to attract dirt and the entire finish is somewhat self cleaning.

As a multiplicity of globules 17a electroplate the peaks 12 by complete penetration of the coating 14, they are not liable to become dislodged through use and even the globules 17b are found to be extremely resistant to detachment from the coating 14.

If desired the surface 12 may be initially quite smooth and can be suitably roughened by the blasting process to provide the required rough surface with its pea ks 12a.

The finished body, in use, is fitted with the usual cutter and comb blades 18,19, tension adjusting nut 20, driving fork 21 and back joint indicated generally at 22.

Whilst specific reference has been made to sheep shears, the method according to the invention could be used on animal clipping handpieces (the term "shearing" including "clipping").

Claims

1. A method of finishing a body of a shearing handpiece comprising forming on or providing at least part of the handpiece body with a rough surface, providing the rough surface with a coating and plating the coated part so as to cause at least some of the plating material to penetrate the coating to provide a finish on the handpiece.

2. A method according to Claim 1 including causing the plating material to take the form of globules or particles at least some of which stand proud of the coating.

3. A method according to Claim 1 or 2 including forming at least said part of the body by a casting process.

4. A method according to Claim 3 in which the casting process is a spheroidal graphite iron casting process.

5. A method according to any preceding claim including subjecting said part of the body to a blasting process to provide or roughen further said rough surface.

6. A method according to Claim 5 including treating said part of the body by a sand or steel blasting process.

7. A method according to any preceding claim including providing the coating as paint.

8. A method according to any preceding claim including immersing the body or at least said part of the body in a solution through which an electric current is passed so that a coating is deposited on the body as an electrophoretic deposit.

9. A method according to Claim 8 including removing the coated body from the solution and heating the body to cure the coating to effect curing thereof, prior to plating.

10. A method according to any preceding claim including causing the coating to flow, accumulate in valleys or crevices in the rough surface body and reduce in thickness on peaks of the rough surface whereby the plating material will tend to penetrate the coating on the peaks.

11. A method according to any preceding claim including providing a smooth part on the body as well as the rough part.

12. A method according to Claim 11 including providing the smooth and rough parts of the body with said coating, removing the coating from the smooth part and plating both the coated and uncoated parts simultaneously whereby the plating material plates the uncoated smooth part as a substantially continuous layer and also plates the coated part.

13. A method according to Claims 11 or 12 including providing said smooth part adjacent a front end of the body which, in use, lies adjacent shearing blades carried by the handpiece.

14. A shearing handpiece body having a part formed with a rough surface, said rough surface having thereon a coating and said coated rough surface being plated, at least some of the plating material penetrating the coating.

15. A shearing handpiece according to Claim 14 in which the plating material lies on the body in the form of discrete globules or particles at least some of which stand proud of the coating.

16. A shearing handpiece according to Claim 14 or 15 in which the body, or at least the part formed with the rough surface, is a casting.

17. A shearing handpiece according to any of Claims 14 to 16 in which rough part of the body has been subjected to a blasting process to produce or roughen further said rough surface.

18. A shearing handpiece according to any of Claims 14 to 17 in which the coating is a paint.

19. A shearing handpiece according to any of Claims 14 to 18 in which the coating is an electrophoretic deposit.

20. A shearing handpiece according to any of Claims 14 to 19 in which the coating is of greater thickness in valleys or crevices than on peaks of the rough surface and the plated material penetrates the thinner coating on the peaks.

21. A shearing handpiece according to any of claims 14 to 20 in which the body includes a smooth part which is not provided with said coating but which is plated with the plating material.

22. A shearing handpiece according to Claim 21 in which the smooth part is adjacent a front end of the body which, in use, lies adjacent shearing blades carried by the handpiece.

23. A shearing handpiece according to any of claims 14 to 22 having a cutter blade and a co-operable comb mounted thereon and means therein by which drive can be transmitted to the cutter blade.

24. A shearing handpiece made by a method according to any of Claims 1 to 13.

25. A method of finishing a body of a shearing handpiece substantially as described herein with reference to the accompanying drawings.

26. A shearing handpiece constructed and arranged substantially as described herein with reference to the accompanying drawings.