GB559177A - Improvements in or connected with machines for cutting coal and like minerals - Google Patents

Abstract

559,177. Coal &c. cutting machines ; ratchet gearing. LOGAN, W. A. - Aug. 5, 1942, Nos. 10908 and 15589. [Class 68 (i)] [Also in Group XXIV] A machine for cutting coal and like minerals into a series of slabs as it advances along the coal &c. face comprises' overcutting, under-cutting and shearing elements, all of the cutter chain type, and a severing cutter which is adapted at intervals to swing into the coal &c. in a substantially vertical plane at right angles to the coal &c. face, the severing cutter, while making this cut, remaining stationary as far as longitudinal advance is concerned. The machine comprises a base A carrying a motor and gear housing B, a shearing cutter C, an undercutter D, an overcutter F adjustably carried by a turret E, and a severing cutter H, the undercutting and shearing chains being driven by sprockets 2, 1, respectively, and the overcutting and severing chains being driven through the undercutting chain. The severing cutter H is carried by a gear box K slidable along its drive shaft M in guides L. In use, the machine is inserted into a recess in the coal &c. face and is then advanced along the face by a haulage cable wound, on a drum J. When a severing cut is to be made, the gear box K is held stationary by a clip engaging the haiilage cable and the cutter H is swung down into the coal ; the cutter H is then returned to the vertical, the clip is released from the haulage rope, and a divided nut is engaged with a screw 18 driven from the machine, whereby the gear box K and cutter H are advanced along the base E at high speed, after which the divided nut is released, and the clip re-engaged with the haulage cable, this being effected automatically by cam action. The swinging of the cutter H is effected through gearing 14, 11, Figs. 4 and 5, driving an eccentric 12 which oscillates two pawls 13 engaging opposed ratchet wheels 10 driving a. worm 9 meshing with a worm wheel 8 carrying the cutter ; one pawl is held out of action by a shroud, stops 16 on the worm wheel 8 acting at the end of each stroke to move the shroud and put the previously inoperative pawl in action, the return stroke then taking place. As the coal is cut away, it is propelled laterally on to a face conveyer N by means of curved guide P and scraper conveyer Q. In another form, the severing cutter is fixed against longitudinal movement relatively to the base A, advance of the machine being stopped while the severing cut is made. Specification 411,256 is referred to. The first Provisional Specification describes a form of apparatus in which the cutter H is replaced by a rotary cutter bar moved up and down as the machine advances so as to produce a sinuous cut.