GB968557A - Double toggle crushing machines - Google Patents

Abstract

968,557. Jaw-crushers. PEGSON Ltd., and R. TABERNER. June 13, 1963 [March 29, 1962], No. 11996/62. Heading B2A. An hydraulic transmission provided in a double-toggle jaw-crusher is incorporated in a pitman transmission 10 between a driving- eccentric 9 and the toggle-plates 11, 12 which drive the movable jaw 8 and is arranged so as to be capable of being set to collapse at a specified load. As described, the pitman comprises an upper sleeve 20 enclosing bearings mounted upon the eccentric and a lower block 22 suspended from the sleeve 20 by four bolts 23 on which it is free to move. Two ram-andcylinder units 27 are bolted to the upper surface of the block, so that the upper ends of rams 29 bear through pads 31 on the underside of the sleeve 20. In operation, pressure-fluid is supplied to the cylinders 27 so that thrust may be relayed from the sleeve to the toggles, and when the desired pressure is attained a pressureoperated switch in an hydraulic-circuit stops the fluid-pump. The pressure is maintained by a check-valve, but in the event of leakage in the system the pressure-operated switch restarts the pump and repressurizes the system. When the jaw 8 meets tramp material, the pressure rises, operating the hydraulic-circuit to relieve the units 27 and thus the load on the pitman, so that movement of the eccentric is not transmitted to the jaw. A pressure-operated switch in the circuit operates an alarm and stops the fluid-pump and the prime mover of the plant, and pressure is maintained in the system until the units are fully retracted. Adjustable stops on the pitman-block 22 co-operate with abutments on the side walls of the machine to limit upward movement of the cylinder-units 27 and keep them clear of the sleeve 20. A front toggle seat-block 19 is located by an hydraulic-cylinder 54, and is clamped on the jaw-stock 7 by a plate 53 actuated by two hydraulic-cylinders 56, supplied with fluid by a hand pump. To keep the cylinder units extended the pressure is maintained by check-valves in the hydraulic lines, the appropriate units being selected by stop valves, and shims 52 are used to vary the fore and aft position of the block 19 relative to the stock 7. To clear tramp material from the jaws, the clamp-plate 53 is released by operation of the cylinders 56, and the block 19 is then released by operation of the cylinder 54, so as to move the block 19 away from the jaw-stock. After removal of shims 52 and swinging back of the jaw-stock 7 under the pull of tie-rods 14, the tramp material is removed, the units 56 are operated to clamp the block 19 and the swing-jaw is operated without the shims and hence with a wider gap, so as to clear any remaining tramp material. The unit 54 is then operated to locate the block 19 and facilitate replacement of the shims 52. When the machine is restarted, the flywheel speed is built up and coupling takes place by gradually extending the rams 29 by priming the cylinders 27, so that the sleeve 20 on the eccentric will progressively engage the rams. Specification 917,743 is referred to.