GB1342254A - Gyratory crushers - Google Patents

Abstract

1342254 Gvratorv crushers PEGSON Ltd 13 Dec 1971 [1 Jan 1971] 9/71 Addition to 1242132 Heading B2A A gyratory crusher of the kind described in Specification 1,242,132, comprises an hydraulic control system to permit relief if uncrushables enter the gap, and automatic resetting of the gap. The bowl 3 is supported by trapping hydraulic liquid on the upper side of pistons 9 in cylinders 6 and adjustment is effected by raising or lowering the pistons 9. The pressure in upper chambers 6a is sensed by a pressure switch 32. When overload ocurs the switch 32 energies a solenoid 34 opening a relief valve 33 and venting the chambers 6a. The lower chambers 6b are maintained pressurized by an accumulator 37 so that the bowl is lifted. The valve 33 remains open for a period determined by a timer 38 after which it closes. Resetting of the bowl is effected as follows. When the bowl is moved to release the uncrushable material a pump motor 30 is energized so that a pump 29 pressurizes the upper chambers 6a as soon as the valve 33 closes. At the correct setting of the bowl, a manually adjustable pointer 42a coincides with an indicating pointer 42b which in turn is actuated in response to the setting of a potentiometer 41 controlled directly by motion of the bowl. This meter is associated wtih the switch gear of the pump motor, and thus coincidence of the pointers stops the motor and consequently further pressurization of the upper chambers. Should the bowl need upward adjustment the pressure in the lower chambers 6b is raised by the pump 29 by actuation of a directional valve 40 controlled by the potentiometer 41. The poteniometer 41 may include switches on each side of any adjusted position to energize the appropriate winding of the valve 40. The potentiometer may be replaced by a limit switch (41a) controlled by a probe (41b) Fig. 3 (not shown). Wedges 14 which centralize the bowl can be automatically withdrawn to permit readjustment of the crushing gap.