GB2198064A

GB2198064A - A device for carrying blades during sharpening

Info

Publication number: GB2198064A
Application number: GB08725212A
Authority: GB
Inventors: Alun Williams; Richard Anthony
Original assignee: Lister Shearing Equipment Ltd
Current assignee: Lister Shearing Equipment Ltd
Priority date: 1986-10-28
Filing date: 1987-10-28
Publication date: 1988-06-08
Anticipated expiration: 2007-10-28
Also published as: GB8625757D0; GB8725212D0; GB2198064B

Abstract

The device enables blades 40 such as those used in animal shearing or clipping machines to be carried for engagement with a grinding disc 44. A blade 40 is carried on mounting means 18 and is in contact with a blade engagement surface 23. In use the blade 40 is urged against the grinding disc 44 by applying a load F to the blade 40 through the blade engagement surface 23. The distance between the blade engagement surface 23 and the mounting means 18 may be infinitely varied by adjustment means 14 or may be varied to give three or more different distances to provide optimum grinding for different designs or sizes of blade 40. <IMAGE>

Description

A CARRYING DEVICE FOR BLADES The invention relates to a carrying device for blades and is particularly concerned with a carrying device for blades of animal shearing or clipping machines.

Blades for such a machine comprise a cutter and a comb, the cutter, when mounted in the machine, being oscillated over the comb by drive means to effect a clipping or shearing operation Such blades require sharpening from time to time and the invention is intended to enable such blades to be carried in a suitable manner for engagement with a grinding disc.

Carrying devices for such a purpose have been proposed hitherto and comprise mounting means for a blade and ablade engagement surface spaced from the mounting means, the surface and mounting means being spaced either by a first distance suitable e.g. for carrying a cutter or a second distance, e.g. suitable for carrying a comb. In one earlier proposal, the mounting means is moved relative to the surface against the bias of a spring and then rotated into an alternative position. However, such an arrangement may not provide a positive positioning of the blade during grinding as the forces on the blade induced bv the grinding wheel can cause oscillation of the mounting against the spring. In another earlier proposal, the mounting means has comprised a pair of plungers which carry mounting pins for the blades.

The plungers are movable between two axial limits so as to position the pins in the alternative positions.

Although the plungers are held in the selected positions by detent means, there is still a rise that they may move during grinding as a result of grInding forces on the blade. Any given blade to be r#ounteo on the carrying device has its own grinong recuirerent which is dependent on the overall design. The blade, once mounted in the cifr, is urged against a grinding disc by applying a loaa to the blade through the blade engagement surface. The zone of the blade at which the load is applied for optimum grinding varies with different makes of the blades.Although the two position devices enable various makes of blades to be carried, the carrier will enable optimum grinding of the blades to be effected only when the aforesaid zone corresponds exactly with the position of the blade engagement surface. Therefore, where the blade zone does not correspond to the position of the blade engagement surface inaccurate grinding results.

One object of the present invention is to provide an improved carrying device which enables a greater range of blades to be sharpened accurately.

According to the invention there is provided a carrying device for a blade comprising mounting means for the blade, a blade engagement surface spaced from the mounting means, and adjustment means for infinitely varying the distance between the surface and the mounting means.

The infinite variation of the distance enables wider range of blades to be sharpened accurately than is possible with the hitherto proposed "two position types because the blade engagement surface can be positioned accurately to suit neros blades.

According to another aspect of the invention there is provided a carrying device for a blade comprising rrounting means for the blade, a blade engagement surface spaces from the mounting means and adjustment means for ad#astinc the distance between the surface and the mountinG means so as to Lrciide three or more different distances.

Preferably, the adjustment means is screw-threaoec means, a cam or other adjustment means.

The mounting means, which may comprise a pair of spaced pins, may be carried by a first member of the device and the blade engagement surface may be on a second member of the device. In such a case, we prefer the adjustment means to be arranged to effect relative movement between the first and second members, and the adjustment means to be screw threaded means.

Another object of the invention is to provide a more positive fixing of the mounting means so that it is less likely to move relative to the surface as a result of grinding forces. In that respect, we prefer to fix the first member to an elongate swingable element. In such a case the second member is preferably mounted on the swingable element for movement by said screw threaded means. Preferably, means are provided to prevent the members from rotating relative to each other about said element.

Such means may include a key and keyway arrangement.

The key and keyway may be provided on any two members of the device and preferably the first member is provided with key and the second member is provided with a corresponding keyway.

The screw threaded means may comprise an external screw thread on the elongate element and an internally screw threaded part which can be screwed along the external screw thread to effect the adjustment of the aforesaid distance, in particular to give infinite variation. Preferably, a blade carried by the device is held, in use, against the surface by magnetic force, i.e. attraction. Such force can be provided by a macnet which may be arranged adjacent the surface.

The blade engagement surface may comprise a fulcrum about which the blade can pivot.

The fulcrum may be positioned beyond a plane containing a further surface of the mounting means whereby the further surface will not interfere with movement of a blade carried by the device about the fulcrum into a desired position when grinding.

The blade engagement surface and the mounting means may be normally biassed towards or away from each other by bias means.

The carrying device preferably arranges the blade in a position inclined from the vertical and allows the blade to pivot into a substantically vertical position as it is moved into engagement with a grinding disc.

A carrying device for blades in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Fig.l is a side view of a carrying device for shearing and clipping blades in accordance with the invention shown partly in cross-section, Fig.2 is an elevation of the device of Fig.l, Fig.3 is a view similar to part of Fig showing a blade in a sharpening position against a grinding disc, and Fig.4 is a cross section through an alternative tpe o carrying device in accordance with the invention.

A firs member 10 is s@itably fixed rigfdiy to the lower er5 of a perciloar 12 (constituting the aforesaid elongate element) e.g. by a transverse lockin screw or a stop nut on the pendulum 12. A second member 13 is mounted for axial sliding on the pendulum 12 and is normally biassed upwardly away from the first member against a sleeve 14 by a spring 15. The sleeve 14 is internally screw threaded and engages screw threads 16 on the pendulum 12. The pendulum is able to swing about its upper end which, in use, is supported by a suitable pivot 17.

Looking at the device in more detail, the first member 10 carries two spaced pins 18 in bores (not shown), the pins projecting from a front face 21 of the first member and being held in the bores by locking screws 19. The upper surface of the first member 10 as viewed in the drawings is formed with a vertical surface 9, for co-operation with the second member 13 as described below, and with a rebate 20. The first member 10 is formed from a non-magnetic material such as aluminium or plastics.

The second member 13 is formed with or carries a magnet 22 having a knife edge 23 contituting the aforesaid blade engagement surface. The magnet is mounted in a rebate 24 and its lower surface 25 projects below a lower surface 26 of the second member 13. The second member 13 is formed with a rear surface 28 which slidably engages the surfaces 9 to prevent relative rotation between the first and second members about the pendulum 12. Such rotation is further inhibited by providing a key 9a on the surface 9 and a keyway2Fa in surface 28 The second member 13 is formed with a boss 29 which is formed with a bore for receiving an unthreaded lower section 30 of the pendulum with close working clearance to permit sliding of the second member 13 axially thereon.

The sleeve 14 can be screwed down to compress the spring 15, and reduce the distance D between the pins 18 and the knife edge 23. The rebate 20 receives the magnet 22 in the lowest position of the second member 13, the compressed spring 15 being received in a counterbore 32 in the second member and/or first member. Unscrewing the sleeve 14 enables the spring 15 to move the second member 13 upwardly along the pendulum to increase distance D. The knife edge 23 is positioned forwardly of the front face 21 of the first member by a distance E (Fig.3).

The first member 10 is provided with two sets of scales 35, 36 on each of its side surfaces and the second member 13 carries a pointer 37 associated with the scales. One set of scales provides settings for grinding with a grinding disc 44 effecting an upward grinding motion as viewed in Fig.1 and the set of scales (not shown) on the opposite side of the second member provides settings for grinding with a downward motion. The scale 35 is used for setting the distance D for a comb and the scale 36 for a cutter, the sleeve 14 being rotated appropriately to move the second member 13 and its pointer 37. Setting details are set out in instructions provided with the device.

The scales could be changed to suit various makes of blades. The scales could be carried by an extended surface 9, the upper surface of member 13 being used to align with the selected graduations.

Alternatively the pointer could be mounted extending da:n##rciyfrom the second member 13 and the scales carried beneath the pointer on the first member 10.

The pendulum comprises a first arm 12a which is screw threaded at its upper end and carries a screw threaded adjustment nut 33.

The nut 33 is rotatably connected to a second arm 12b having an eye 34 at its upper end for receiving the pivot 17. The nut 33 enables the length of the pendulum 12 to be adjusted.

In use, a blade 40, (indicated in broken lines) is placed on the device so that the pins 18 extend part way through the usual blade mounting apertures 42 and a rear face of the blade engages the knife edge 23 of the magnet, the blade being held in an inclined sense against the knife edge 23 and an upper edge 41 of the magnet 22 by magnetic force. The magnet may comprise a single magnetic piece of any suitable overall shape, and may comprise a flat magnetic piece sandwiched between suitably extending magneticabbe members as shown in the Figures.

To grind the blade 40 the device is swung about the pivot 17 so that the lower end of the front face of the blade moves into engagement with a side face 43 of a grinding disc 44.

Load applied to the device in direction F causes the blade 40 to swing clockwise about knife edge 23 clear of edge 41 and into the Fig.3 position flat against the grinding wheel face 43, the diameter of each pin 18 being smaller than that of the corresponding aperture 42 to permit such swinging. It will be noted that the clearance E ensures that the face 21 of the first member will not interfere with such swinging movement. The loading F is applied to the blade solely through the knife edge 23, the blace being free to adopt a position flat against the wheel face 43. After grinding, the device is moved awav from the wheel 4 and the blade resumes its inclined position.

The distance between the apertures 42 and a line 42a (contituting the aforesaid zone) along which the blade will engage the knife edge 23 will vary with different types of blade and the ability to vary the distance D infinitely makes the invention particularly versatile and aids accurate grinding.

Also, the rigid fixing of the first member 10 to the lower end of the pendulum 12 provides a firm tin for the blade 40 as crir- # inc forces are transrited directly fror the f$## merger to the pendulum rather than via a spring or detest as in the aforesaid prior proposals. To increase further the versatility of the device, a number of alternative first members may be provided for mounting on the pendulum 12, the members 10 having pins 18 spaced by different distances G to suit blades made by different manufacturers.

Instead of holding the pins 18 in position by locking screws 19, the pins 18 could be roll pins held frictionally in bores or the pins 18 could be screw threaded and screwed into the bores.

In Fig.4 the first member 10 has an extended surface 9 formed with a key 50. The second member 13 is formed with a keyway 52 which receives the key whereby relative rotary movement about pendulum 12 is prevented. The magnet 22 is arranged between upper and lower steel plates 53, 54 which have staggered front edges 53a, 54a for engagement with the blade 40 part of which is shown in broken lines. The second member 13 is formed with a screw threaded bore 55 which receives a screw-threaded sleeve 56, the sleeve projecting beyond the upper surface of member 13 and being slidable on pendulum 12. The pendulum carries a circlip 57 in a peripheral groove, and a helical compression spring 58 is positioned under load between the circlip and the upper end of the sleeve 56. An internally screw-threaded adjustment sleeve 14 screws on to the sleeve 56 and has a shoulder 58 at its upper end which engages the circlip 57.

Rotation of the adjustment sleeve 14 will either draw the member 13 upwardly against the bias of the spring 58 or allow it to move downwardly under the influence of the spring. The position of the upper member 13 relative to the lower member can be set using scales as described with respect to Figs.1 to 3. The member 10 is attached to the pendulum 12 by means of a bolt 60.

Claims

CLAIMS 1. A carrying device for a blade comprising mounting means for the blade, a blade engagement surface spaced from the mounting means, and adjustment means for infinitely varying the distance between the surface and the mounting means. 2. A carrying device for a blade comprising mounting means for the blade, a blade engagement surface spaced from the mounting means and adjustment means for adjusting the distance between the surface and the mounting means so as to provide three or more different distances. 3. A device as claimed in Claim 1 or Claim 2, wherein the mounting means comprises a pair of spaced pins. 4. A device as claimed in Claim 1, 2 or 3 wherein the mounting means is carried by a first member of the device and the blade engagement surface is on a second member of the device. 5. A device as claimed in Claim 4 wherein the adjustment means is arranged to effect relative irovement between the said first and second members. 6. A device as claimed in Claim 4 or Claim S wherein the first member is fived to an elongate swingable element. 7. A device as claimed in Claim 6, wherein the second member is moveably mounted on said elongate swingable element. E. A device as claimed in Claim 7, wherein means are provided to prevent said first and second members fror rotate relative to each other about said element. 9. A device as claimed in Claim 8, wherein the means to prevent said members from rotating includes a key and keyway arrangement. 10. A device as claimed in Claim 9, wherein the means to prevent said members from rotating includes a key provided on the first member and a corresponding keyway provided on the second member. 11. A device as claimed in any preceding claim wherein the adjustment means comprises screw-threaded means. 12. A device as claimed in any of Claims 1 to 10 wherein the adjustment means is a cam. 13. A device as claimed in Claim 11, wherein the screw threaded means comprises an external screw thread on the elongate swingable element and an internally screw-threaded part which can be screwed along the external screw thread to effect the adjustment of the aforesaid distance. 14. A device as claimed in any preceding claim, wherein a blade carried by the device is held, in use, against the said blade engagement surface by magnetic force. 15. A device as claimed in Claim 14, wherein the magnetic force is provided by a magnet which is arranged adjacent the said blade engagement surface. 15. A device as claimed in any preceding claim wherein said blade engagement surface comprises a fulcrum about which a blade carried by the device can pivot. 17. A device as claimed in Claim 16, wherein the said fulcrum may be positioned beyond a plane containing a further surface of the monitoring means whereby the further surface will not interfere with movement about the fulcrum of a blade carried by the device into a desired position when grinding. 18. A device as claimed in any preceding claim, wherein the blade engagement surface and the mounting means are biased towards or away from each other by bias means. 19. A device as claimed in any preceding claim, wherein the device arranges a blade carried by the device in a position inclined from the vertical and allows the blade to pivot into a substantially vertical position as it is moved into engagement with a grinding disc. 20. A carrying device for a blade substantially as described herein with reference to Figures 1, 2 and 3 of the accompanying drawings. 21. A carrying device for a blade substantially as described herein with reference to Figure 4 of the accompanying drawings. Amendments to the claims have been filed as follows CLAIMS

1. A carrying device for a blade comprising mounting means for the blade, a blade engagement surface spaced from the mounting means, a blade in use being urged against a grinding surface by a load applied to the blade through the blade engagement surface, and adjustment means for infinitely varying the distance between the blade engagement surface and the mounting means.

2. A carrying device for a blade comprising mounting means for the blade, a blade engagement surface spaced from the mounting means, a blade in use being urged against a grinding surface by a load applied to the blade through the blade engagement surface, and adjustment means for adjusting the distance between the blade engagement surface and the mounting means so as to provide three or more dfffeet ("stales.

3. A device as claimed in Claim 1 or Claim 2, wherein the mounting means comprises a pair of spaced pins.

4. A device as claimed in Claim 1, 2 or 3 wherein the mounting means is carried by a first member of the device and the blade engagement surface is on a second member of the device.

5. A device as claimed in Claim 4 wherein the adjust ment means is arranged to effect relative movement between the said first and second members.

6. A device as claimed in Claim 4 or 5 wherein the first member is fixed to an elongate swingable element.

7. A device as claimed in Claim 6, wherein the second member is moveably mounted on said elongate swingable element.

8. A device as claimed in Claim 7, wherein means are provided to prevent said first and second members from rotating relative to each other about said