GB642315A - Improvements in power transmission in jaw crushers - Google Patents

Abstract

642,315. Jaw crushers. GAULDIE, K. April 25, 1947, No. 11180. [Class 59] [Also in Group XXIX] A jaw crusher comprising a hydraulically operated reciprocating jaw and a non- reciprocating jaw between which material is caught and crushed during active strokes of the former and between which, during intervening intervals, the crushed material descends at a mean speed limited by gravity, has, for the purpose of increasing the time available for outfall of crushed material, means provided whereby the time interval between the end of a crushing stroke and the beginning of the next crushing stroke sensibly exceeds half the period of a complete oscillation of the jaw. A swing jaw 1 of a jaw crusher is operated by a ram 4 reciprocated in a cylinder 8 by pressure fluid delivered through a pipe 12 from a cylinder 10 by a plunger 9 reciprocated in the cylinder 10 by a crank driven from a continuously rotated shaft 11. A valve 17, Fig. 3, in a pipe connection 14 between the cylinder 10 and a sump 19 is so opened and closed by a cam on a shaft rotated at half the speed of the shaft 11 that successive reciprocations of the plunger 9 deliver liquid alternately to the ram cylinder 8 and to the sump 19; thus for a quarter of the period of complete oscillation of the jaw 1 the jaw is moved forward making its crushing stroke, for the next “ of the period is moved back by a spring 6 against an adjustable stop 7 in the ram cylinder 8 and for the next ¢ period is held in this retracted position. A relief valve 18 opens if the pressure in the system becomes too great as the result of uncrushables caught between the crusher jaws. Leakage from the system is returned by pipes 22 to the sump 19 and is made up during the last part of suction stroke of the plunger 9 after the ram 4 has reached the stop 7, through the valve 17. Two crusher units, which may be mounted side by side or one below the other, may be operated alternately. either by two plunger arrangements 9, 10 driven from the same shaft 11, as is shown in Fig. 3, or by a single plunger arrangement 9, 10 delivering alternately to the two moveable jaws. In a modification, Fig. 9, a quick forward and delayed return stroke of the jaw may be obtained without the use of control valves by suitably combining the action of a number of plungers: a plunger 30 reciprocates in a cylinder 31 at twice the speed of a plunger 32 in a cylinder 33 both delivering to the same ram cylinder 8. The number, displacement, frequency of reciprocation and phase relationship of the plungers may be varied as required. A check valve 27 for make-up liquid is provided. In place of the stop 7 in the ram cylinder 8 there may be provided a stop mechanism, Fig. 8. comprising a stop 53, normally held forward by a spring 56 more powerful than the jaw return spring 6, carried on a shaft 52 to which is attached a piston 54 moving in a cylinder 55. An inlet port 57 of the cylinder 55 is connected to the outlet port of the relief valve 18 and an outlet port 58 is connected to the sump so that if uricrushables enter the crusher and pressure builds up to open the valve 18, the stop 53 is moved back until the port 58 is uncovered, thus allowing the crusher jaws to open an extra amount.