Patent GB-599659-A (GB)
Title: Improvements in the manufacture of concrete and like slabs
IPC: B65G49/08
Filed: 1945-10-19
Abstract: 599,659. Load-handling apparatus; lifting - cradles; chain railways. ALLTOOLS, Ltd., and HALL, E. H. S. Oct. 19, 1945, No. 27558. [Classes 78(iii), 78(iv) and 104(ii)] Moulds 10 charged with concrete on a conveyer 11 are delivered one at a time to a platform 19 at the same level, and are picked up in succession from the platform by a trolley 12 which is suspended from a hoist 30 so as to embrace the platform, and which has a series of superposed mould receiving frames for engaging under opposite, ends of the moulds to pick them up as it is lifted in stages by the hoists. The apparatus is applicable to the plant for the mass-production of concrete building units described in Specification 599,619, the hoist 30 being traversed on a rail 28 to carry .the loaded trolley to a drying chamber, through which it is slowly drawn on rails by a chain. The moulds are then unloaded from the trolley by a similar platform and hoist apparatus and passed one at a time .to a finishing conveyer, which may be a part of the conveyer 11 so that, after passing an opening station, the empty moulds pass back to the filling station for a further cycle. In the construction shown, the trolley 12 comprises a base frame 21 with uprights 32 carrying cross angles 31 which constitute the aforesaid superposed frames for successively engaging under the ends of successive moulds as they are run by hand on to the table 19. The hoist is controlled automatically by a switch 40, each mould as it is thrust home moving an actuator 42 inwardly to close the circuit of the hoist motor which remains energised until the end of the mould clears the upper edge of the actuator 42 and releases it. By this time, the next lower pair of cross angles 31 will have arrived level with the platform to engage under the next mould. Accuracy of working is assured by making the vertical position of the actuator, and its moment of release by the mould, adjustable; a supplementary manual push-button 43 is, however, provided to enable the hoist to be lowered should the positioning be inaccurate. The platform 19 has rollers 20 for carrying the moulds, and is constructed with vertical frame members 51 suspended on cords 50 to slide between fixed uprights 46 in a pit 45. Normally the platform is stationary, but it can yield downwardly against the action of a counterweight 44 if the hoist is lowered too far when making a positioning adjustment by the push-button 43. The trolley has wheels 22 for running on the rails of the drying chamber. A depending dog 36 adapted to engage the towing chain is pivoted at 34 to enable the trolley to be moved on by hand ahead of the chain, and also to enable the dog to be rocked clear of the chain. An upstanding arm 35 of the dog bears against a frame member of the trolley to take the tractive pull, and rests against the rear face of a buffer 33 when inoperative. The similar platform and hoist apparatus for unloading the trolley on to the finishing conveyer differs in certain respects; one pair of rollers 20 on the platform is driven, the hoist switch is manually closed to lower each mould on to the platform and then opened automatically, and an automatic switch actuated by descent of the platform against its counterweight breaks the hoist circuit should the trolley descend too far owing to failure of the main switch. Specification 589,449, [Group V], is referred to regarding details of the moulds used with the apparatus.