GB682603A - Improvements in or relating to coal cutting machines - Google Patents

Abstract

682.603. Endless-chain mining-machines. AUSTIN HOY & CO., Ltd. Dec. 20, 1950 [Dec 20, 1949], No 32650/49. Addition to 630,112. Class 68(i) To permit an overcutter or an undercutter jib to be moved vertically away from the normal plane of operation so as to facilitate the flitting of the machine it is arranged that in the case of an undercutter the jib post 124 of the jib 23 is pivotally connected by guide links 25 which in turn are pivotally connected to a back hanger bracket 16 that can be rotated about the vertical drive sprocket axis 14. When in the lowermost position i.e. the jib is adjacent the floor, a block 22 on the jib interlocks with a block 19 on the bracket, the two blocks being clamped together by a screw 21. On release of the screw, the jib can be swung upwards and outwards because of the guide links until it lies in the plane of the drive sprocket so as to be ready for rotation about the axis of the sprocket 14. In this position, the blocks have been separated from one another and, to hold the jib in such a position, a pin 28 is passed through a hole 30 in the block to rest on a knee 29 formed on the block 19. In a modification, the interlocking faces of the blocks are in the form of an outwardly inclined dovetailed connection whilst the hinged guided sections are provided with enough play at the hinges to permit of such sliding. In another modification, the guide sections are replaced by a link connecting the jib post and hanger bracket and the guides on the jib post and bracket are so curved as to lead the chain from one to the other when in the working position and to be sufficiently separated from one another in the position in which the jib is moved away from the working plane as to permit the chain to extend loosely between them. Specification 626,080 also is referred to. The Provisional Specification describes also modified means for locking the jib to the hanger bracket when in a raised position.