GB2536058A

GB2536058A - Guide block

Info

Publication number: GB2536058A
Application number: GB1503821.9A
Authority: GB
Inventors: Alun Harris Williams John; Williams Jeremy; James Howell Robin
Original assignee: Lister Shearing Equipment Ltd
Current assignee: Lister Shearing Equipment Ltd
Priority date: 2015-03-06
Filing date: 2015-03-06
Publication date: 2016-09-07
Anticipated expiration: 2035-03-06
Also published as: GB201503821D0; GB2536058B

Abstract

A guide block 12 for the upper blade 10 of a cutter blade pair. The guide block 12 is of unitary construction and includes a centre section 22, side sections 24 provided on opposing sides of the centre section 22 and a lower surface 23 which, in use, rests against a cutter blade 10 to which the guide block 12 is fitted. The centre section 22 is provided with a recess to, in use, receive the crank pin of the drive shaft of a cutting apparatus, and the side sections 24 are sized and shaped with projections 40 so as to be receivable, in use, in guide slots of a cutting apparatus. Troughs 38 are provided in each side section 24 to which oil may be applied through existing apertures in the cutting apparatus and then pass through bores 42 in the projections 40 to enable lubrication of the regions between the lower surface 16 of the cutter blade 10 and the upper surface of the lower blade of the blade pair.

Description

Guide Block The present invention relates to a guide block for a cutter blade of a cutting apparatus.

Particularly, the present invention relates to a guide block for the cutter blade of a handheld cutting apparatus suitable for the cutting of animal hair.

A handheld cutting apparatus suitable for the cutting of animal hair typically includes a pair of opposing blades. These comprise a fixed lower blade and a movable upper blade. The upper blade is supported by the cutting apparatus so as to be able to be reciprocated in a side to side manner relative to the lower blade by a drive shaft of the cutting apparatus. The upper blade is typically provided with a formation which cooperates with a crank pin of the drive shaft to convert rotational motion of the drive shaft into reciprocating linear motion, and further formations which guide the movement of the upper blade in said reciprocating linear motion According to a first aspect of the present invention there is provided a guide block for the upper blade of a cutter blade pair, the guide block being of unitary construction and including a centre section, side sections provided on opposing sides of the centre section and a lower surface which, in use, rests against a cutter blade to which the guide block is fitted, the guide block further including formations configured to facilitate connection of the guide block to a cutter blade, wherein the centre section is provided with a recess to, in use, receive the crank pin of the drive shaft of a cutting apparatus, the side sections being sized and shaped so as to be receivable in guide slots of a cutting apparatus, in use, wherein each side section is provided with a projection which extends from the lower surface of the guide block, and the projection is provided with a through bore for the passage of a lubricating medium Each side section may further be provided with a reservoir for a lubricating medium, wherein the through bore of the projection extends from the reservoir to an aperture in the end of the projection.

The formations configured to facilitate connection of the guide block to the cutter blade may comprise through apertures of the guide block. Alternatively, the formations configured to facilitate connection of the guide block to the cutter blade may comprise projections extending from the lower surface of the guide block. Such projections may be deformable so as to facilitate connection of the guide block to a cutter blade.

The guide block may be formed from metal by a metal injection moulding operation.

According to a second aspect of the present Invention there is provided the combination of a cutter blade and the guide block described with reference to the first aspect.

According to a third aspect of the present invention there is provided a cutting apparatus having cutter blade and guide block combination described with reference to the second aspect.

An embodiment of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 shows a top plan view of a cutter blade and a guide block according to the present invention; Figure 2 shows a rear view of the cutter blade and guide block of figure 1; Figure 3 shows the cross-sectional view indicated by arrows A-A of figure 1; Figure 4 shows a bottom plan view of the cutter blade and guide block of figure 1; Figure 5 shows the cross-sectional view indicated by arrows B-B of figure 1, Figure 6 shows a perspective view of the cutter blade and guide block; Figure 7 shows a further perspective view of the cutter blade and guide block; Figure 8 shows a top plan view of a guide block according to the present invention; Figure 9 shows a rear view of the guide block of figure 8; Figure 10 shows a front view of the guide block of figure 8; Figure 11 shows a bottom plan view of the guide block of figure 8; Figure 12 shows the cross-sectional view indicated by arrows C-C of figure 8, Figure 13 shows a side view of the guide block of figure 8; Figure 14 shows a perspective view of the guide block; and Figure 15 shows a further perspective view of the guide block Referring firstly to figures 1 to 7 there is shown the combination of a cutter blade 10 and a guide block 12. The cutter blade 10 includes an upper surface 14 and a lower surface 16. The cutter blade 10 further includes a plurality of sharpened teeth 18 which are arranged along a forward edge 20 thereof The cutter blade 10 is the upper blade of a blade pair which further comprises a lower blade (not shown). In use, the lower blade is retained in a fixed position within a cutting apparatus. The upper blade 10 is retained by the cutting apparatus in contact with the lower blade and, in use, is reciprocated linearly in a side to side manner over the lower blade.

The guide block 12 is a unitary or single-piece component which may be formed by, for example, a moulding operation. The guide block 12 may preferably be formed from metal utilising a metal injection moulding (MINI) operation. For example, the guide block 12 may be formed from a high nickel and carbon content alloy steel (0.6%C, 8%Ni). So as to enable the guide block 12 to be formed utilising a metal injection moulded operation, it will be appreciated that the steel is initially in a powder form and mixed with an appropriate binder material. Once the binder and powder have been injected, the moulding can be cured and subsequently sintered in the normal manner and then processed to provide the desired material characteristics.

For example the moulding may be case hardened. In an alternative embodiment, the guide block may be formed from a plastic material such as, for example, nylon.

The guide block 12 includes a centre section 22 and opposed side sections 24 provided on respective opposite sides of the centre section 22. Between each side section 24 and the centre section 22 there is provided a respective attachment section 26 of the guide block 12. The function and configuration of the sections 22,24,26 are described in greater detail below. The guide block 12 has a lower surface 23 (see Figure 9) which, in use, faces and rests against the upper surface 14 of the cutter blade 10.

Looking firstly at the centre section 22, this comprises a forward wall 28 and opposed side walls 30. The term "forward" is construed with reference to the forward edge 20 of the cutter blade 10 to which the guide block 12 is attached, in use. The walls 28,30 define a recess or pocket 32 of the guide block 12 which, in use, receives a crank pin of a cutting apparatus. As can be seen from the figures, the pocket 32 of the guide block 12 aligns with a corresponding cut out 34 of the cutter blade 10.

Each side section 24 is substantially rectangular when viewed in plan. The upper surface 36 of each side section 24, which is the surface opposite to the lower surface 23 of the guide block 12, is provided with an optional trough 38. Extending from the lower surface 23 of the guide block 12 in the region of each side section 24 is a substantially cylindrical projection 40. As can be seen from the cross-sectional views (figures 3 and 12) each projection 40 is provided with an optional through bore 42 that extends between the trough 38 and an aperture 44 provided in the end of the projection 40. In use, the projections 40 are received in complementary apertures 46 of the cutter blade 10. The length of each projection 40 is less than the thickness of the cutter blade 10 In the embodiment shown, each attachment section 26 includes a through aperture 48 which, in use, accommodates a rivet 50 or similar fastener in order to attach the guide block 12 to the cutter blade 10. The rivets 50 are received in appropriately configured through apertures 52 of the cutter blade 10. In the embodiment shown, the attachment sections 26 have a thickness that is less than that of the side sections 24. As such, an inclined transition 54 is provided between each side section 24 and its adjacent attachment section 26. Receipt of the projections 40 in the cutter blade apertures 46 may be utilised to align the guide block 12 with respect to the cutter blade 10 prior to connection thereto.

In an alternative embodiment, the guide block 12 may be provided with integral means to facilitate connection of the guide block 12 to the cutter blade 10 For example, in place of the through apertures 48, the guide block 12 may be provided deformable projections. Such projections may be received in the cutter blade through apertures 52 and thereafter deformed in order to retain the guide block 12 in association with the cutter blade 10.

In use, the guide block 12 fulfils a number of functions. As described above, the centre section 22 defines a pocket 32 within which the crank pin of a cutting apparatus is received, in use. The crank pin is mounted to a drive shaft of the cutting apparatus, and is positioned eccentrically with respect to the axis of rotation of the drive shaft. As will be readily understood by the skilled addressee, rotation of the drive shaft causes the crank pin to bear alternatively against the opposed side walls 30 of the pocket 32. This, in turn, drives the guide block 12 and cutter blade 10 combination in the side to side manner described above.

The side sections 24 of the guide block 12 are used to regulate the side to side motion of the guide block 12 and cutter blade 10 combination, in use. The side sections 24 are each received in a respective slot of the cutting apparatus. The slots are aligned and define the required reciprocating travel path of the guide block 12 and cutter blade 10 combination. The side sections 24 are received in a free running fit in the slots.

The configuration of the side sections 24 having the troughs 38 and through bores 42, further enables lubrication of the blade pair to be effected, in use. The trough 38 provided in each side section 24 may be provided with a volume of lubrication fluid such as, for example, oil. The oil may supplied to the troughs 38 through pre-existing apertures in the cutting apparatus. The oil passes through the bores 42 in the projections 40 before exiting through the apertures 44. The oil is able to thus lubricate the contact regions between the lower surface 16 of the cutter blade 10 and the upper surface of the lower blade of the blade pair.