Patent GB-970630-A (GB)
Title: Improvements in or relating to material handling equipment
IPC: B21D43/10
Filed: 1962-11-05
Abstract: 970,630. Stamping; blanks transferring. B. J. WALLIS. Nov. 5, 1962 [Nov. 6, 1961], No. 41721/62. Heading B3Q. A press unloader comprises a support plate adapted to be mounted in a fixed position relative to the press, a drive assembly mounted on the plate comprising a rack operably connected with the movable ram of the press and a gear driven by the rack, a tray assembly mounted on the plate comprising a gear drivingly connected with the drive assembly gear, a tray support mounted on the plate for pivotal adjustment about the tray assembly gear axis, a tray supported on the tray support for reciprocating movement thereon and a gear rack on said tray meshing with the tray assembly gear. The unloader comprises drive and tray sub-assemblies. The drive assembly comprises a housing 52, attached via a base 46 to a platen 24 of a conventional press, in which is mounted a vertically reciprocating rack 60 engaging a change gear train 56, 58, 64 which drives the tray assembly via shafts 66, 68, and a rubber coupling 67. A lost-motion connection is provided between the rack 60 and a ram bracket 38 by a jaw structure 40 comprising a frame 70, on which are pivoted a pair of inwardly spring biased jaws 72, 74 which engage an annular groove 91 of a coupling shaft 92, the upper end of which passes through the centre hole 93 of the frame 70 and the lower end of which is screwed to the rack 60. The downward travel of the rack is limited by an adjustable collar 94 which abuts the housing 52. The pointed end 98 of a vertical bar 96 bolted to the housing enters the hole 93 to open the jaws out of engagement with the shaft 92. The tray assembly comprises an adjustable bracket 100 mounted on the base a support casing 108 which is angularly adjustable about and journalled on a pinion shaft 106 relative to the bracket and a rack bar 120 supported by tapered rollers 110 on the casing on which is detachably mounted a transfer tray 44. Operation.-With the jaws locked on the shaft 90 downward movement of the press ram causes the rack to drive the gear train, which, via pinion 122 retracts the tray 44 with an ejected workpiece therein. When the jaws strike the pointed end of the bar 96 they are disengaged from the shaft and simultaneously the collar 94 abuts the housing 52 to halt the the rack 60. The press continues its working stroke and upon its upward stroke the sequence is reversed to advance the tray during the latter part of the stroke. The component ejected from the press on to the tray is subsequently transferred upon retraction to a container &c. In a modification, the lost motion connection comprises a headed shaft 152 having an annular groove 174 and a shoulder 176, a drive rack sleeve 158 having four radial holes 164 into which are fitted balls 166 and an enlarged end 160 providing internal and external shoulders 178, 180 respectively and a stepped bore sleeve 154 having an annular groove 168 and a shoulder 169. In operation, during the latter part of the upward stroke of the press ram the shaft groove 174 registers with the balls and the shoulders 176, 178 engage, the upward pull on the rack 158 causing the balls to move inwardly out of the groove 168 to disengage the rack 158 from the fixed sleeve 154 and couple it to the shaft 152. Continued upward movement of the rack drives the tray via the change gears to its extended position whilst the downward movement of the ram reverses the sequence, the registering of the sleeve groove 168 and the engaging of the shoulders 180, 169 causing the balls to disengage the shaft from the rack and locking the rack to the fixed sleeve 154.