Patent GB-684800-A (GB)
Title: Improvements in and relating to conveyor mechanism
IPC: B23Q7/03
Filed: 1950-11-14
Abstract: 684,800. Gear-finishing. MICHIGAN TOOL CO. Nov. 14, 1950 [Feb. 20, 1950], No. 27843/50. Class 83 (iii). [Also in Group XXX] Mechanism for conveying work-pieces into and out of position for engagement by a workengaging element comprises an endless flexible conveyer movable past the work-engaging element and having means for releasably supporting the workpieces in spaced relation therealong, means for moving the conveyer to successively position the work-pieces for engagement by the work-engaging element, means for disengaging each work-supporting means from a work-piece when the latter is engaged by the workengaging element, and means for causing said work-supporting means to again engage the work when disengaged from the work-engaging element. In a machine for finishing gear clusters the conveyer consists of links 34 each comprising a pair of side links 35 joined at their ends to adjacent links by vertical pivot-pins 39 and provided with two pairs of rollers 41 running on a supporting track 31. Each link 34 has a pair of inverted L-shaped jaws 45 connected by a spring 53 for gripping a gear cluster 47. When a gear cluster is absent, pins 55 restrict inward movement of the jaws. The conveyer travels through a number of finishing machines 12 each with a headstock 23, a tailstock 25 and a rotary cutter 21. The headstock and tailstock are respectively retractable by cylinders 27, 29. In operation, the conveyer is intermittently advanced so that a gear cluster is positioned in register with the head and tailstock of each of the machines simultaneously. A switch operated by the driving gear then causes each headstock and tailstock to move inwardly, a check-valve in the feed to cylinder 27 causing the headstock to move more slowly than the tailstock. When the gear cluster in each machine is engaged by the head and tailstock the members 45 are released by depression of a plunger 71 on to the short arms of the members 45 through operation of a rack-and-pinion gear 65, 69 by a cylinder 61 actuated by switches closed by the head-stock. At the same time the machines are automatically switched on for a predetermined time to operate on the gear clusters. After machining, a further set of switches is closed to cause the cylinders 61 to return the members 45 into engagement with each gear cluster, retract the head and tailstocks, and operate the driving gear to advance the conveyer to position the next gear cluster in each machine. The driving gear comprises a cylinder 77, in one of the machines, whose piston-rod 79 carries at its outer end a block 81 on which is pivoted a pawl 83 restricted to movement forwardly of its vertical position, Fig. 4. An extension of block 81 carries a pin 121 engageable with an inverted L-shaped member 95 pivoted on a pair of blocks, (not shown), adjustably secured to the track 31 and which member is normally spring-pressed upwardly to the chain line position shown. On the forward movement of block 81, pawl 83 engages one of a number of projections 57 of which one is on each link 34 and moves the conveyer by the length of a link. Towards completion of the movement pin 121 engages member 95 and presses the face 117 thereof against the forward face of the engaged projection 57 so as to lock the conveyer in position. In a modification, Fig. 10, straight double-arm cranks 45<SP>1</SP> replace the jaws 45 and the spring 133 which replaces spring 53 is only a light spring. Jaws 491 grip the gear cluster 471 firmly by a toggle link 125 connecting the short upwardlyprojecting arms of cranks 45<SP>1</SP> and are held in an over-centre position by interengaging projections 134 on the toggle. The toggle is broken to release the gear cluster by a pin 145 moved downwardly on to the centre pin 129 of the toggle by a bell-crank 143 coupled to the pistonrod of a cylinder 61<SP>1</SP>.