Mineral cutter system

This invention relates to a mineral cutter system, of the known kind comprising a sleeved box, the sleeve receiving a pick shank, and to a rotary drum or disc provided with such a cutter system.

A widely used system for mineral cutting/winning operations, or for road planning as part of road re-surfacing operations, comprises a pick box welded on to a power driven drum or disc carrying say fifty boxes, with the box having a bore to receive a replaceable, collared sleeve, which in turn has a bore to receive a circular section shank of a mineral cutter pick, the pick, when worn or damaged being removed and replaced, and similarly the sleeve, the objective being to protect the box from damage. Should a certain number of boxes become damaged, box replacement is unavoidable, and if the drum or disc is operating in a UK coal mine, regulations demand that the drum or disc be brought to the surface, or possibly to a safe area, for removal of the damaged box(es) for replacement boxes to be welded in their place(s).

Some picks operate on the so-called point attack principle, in which case an ability for the pick to be free to rotate about its longitudinal axis is desirable.

Other picks operate on a forward attack, or semi-forward attack principle, requiring a specific, non-rotatable orientation.

A basic object of the invention is the provision of an improved mineral cutter system, of the sleeved kind able to accommodate either a point attack pick, or a semi-forward attack pick.

According to a first aspect of the present invention there is provided a mineral cutter system comprising a pick box adapted to be secured, by welding, to a powered drum or disc and having a bore to receive a replaceable sleeve having a collar to limit the penetration of the sleeve into the bore of the pick box, the sleeve having a circular section bore to receive a circular section shank of a replaceable mineral cutter pick, characterised in that the bore of the pick box incorporates at least one flat, and the sleeve is provided with at least one external flat adapted, when fitted into the bore of the pick box, to engage the flat of the bore, whereby the sleeve is non-rotatable with respect to the box, and the collar of the sleeve is both recessed to accommodate a circular collar of a point attack pick, and slotted to provide opposed abutment faces to engage a pair of opposed flats of a non-rotatable, semi-forward attack pick.

Either a point attack pick or a semi-forward attack pick may be fitted in the same sleeve and pick box in accordance with the invention, providing dual cutting modes and hence greater flexibility of use of the same drum or disc.

The bore of the pick box is provided with two opposed flats.

The bore of the pick box is provided with four opposed flats.

The bore of the pick box is provided with six opposed flats.

The bore of the pick box is provided with eight opposed flats.

The sleeve is provided with a corresponding number of flats to that of the bore.

The sleeve is provided with a circumferential groove to receive a retaining device to engage the bore of the pick box to prevent inadvertent extraction of a sleeve from its receiving bore.

The retaining device is of synthetic plastics.

The retaining device is provided with multiple deformable ribs.

The shank of the pick, whether point attack or semi-forward attack is provided with a retaining device.

The retaining device of the shank is a spring steel, split collar.