Patent GB-649100-A (GB)
Title: Material loading apparatus
IPC: E02F3/358
Filed: 1947-08-08
Abstract: 649,100. Load-handling machines. JOY MANUFACTURING CO. Aug. 8, 1947, No. 22058. Convention date, Feb. 18, 1942. [Class 78 (iii)] In material loading apparatus having a turntable for swinging the apparatus horizontally, the swinging means comprises two oppositelyacting devices arranged at one side of a base supporting the turntable and respectively operating to swing the turntable from either side of the base to a central position. A mine car loader comprises a vertically swinging shovel (not shown) mounted in a frame supported by a turntable 6, Fig. 4, which swings about a vertical pivot 5 on a base comprising a platform 2, the base being powered along a rail track (not shown). Figs. 3, 4 and 6.-Oppositely acting cylinders and pistons 21, 22 are secured in alignment to the underside of platform 2 and connecting links 20 are pivoted to pistons 22 and to arms 26 pivoted at points 27 and 28 to the underside of platform 2. The free ends of arms 26 abut on opposite sides of a peg 30 secured to turntable 6 and passed through an arcuate slot 31 in platform 2. A cylinder 52 is also fixed on the underside of platform 2 and its piston 53 is secured to a plunger 54 engageable in a recess 56 in the turntable 6 but normally withheld by a spring 57. When pressure fluid is supplied to the three cylinders 21 and 52 simultaneously by a foot-operated valve (not shown), the arms 26 are urged to the position shown, Fig. 3, so that if peg 30 is displaced either side of central one of the arms 26 engages it and moves it back to the central position, while at the same time plunger 54 is pressed against the underside of the turntable until centred, when it enters recess 56 to lock the turntable. Upon connecting the cylinders to exhaust plunger 54 retracts and the turntable can be moved, peg 30 displacing one or other of the pistons 22 during the movement. Figs. 10, 13 and 15.-Cylinders 65 are secured beneath platform 2 as in the previous embodiment. Their pistons are interconnected by a pair of rods 67 rigidly secured to the pistons and to a block 68 having a slot 69 in which a peg 70 may slide, the peg being passed through arcuate slot 71 in the platform 2 and secured to turntable 6. Pressure fluid is supplied to the outer end of one or other of the cylinders by means of separate valves worked by two rods 89, Fig. 15, in turn actuated through rocker'102 or bell-crank 99 respectively, a foot-plate 95 being rocked to the left to actuate rocker 102 and to the right to actuate bell-crank 99 through an arm 96 and link 98. This moves the turntable in either desired direction or stops the movement when foot-plate 95 is horizontal, when both valves connect their cylinders to exhaust. The speed of the movement of the turntable is controlled by a byepass valve 73 which permits a limited flow of fluid between the inner ends of cylinders 65, which are sealed for this purpose so that an isolated body of fluid is transferred between them. The valve, Fig. 13, comprises passages 78, 79, allowing flow in opposite directions against the pressure of spring-loaded balls 80, 81. Specification 649,101 is referred to.