GB723691A - Improvements in apparatus for lifting freshly pressed moulded articles from mouldingpresses - Google Patents

Abstract

723,691. Feeding endless conveyers. DORSTENER EISENGIESSEREI UND MASCHINENFABRIK AKT.-GES. June 26,1952, No. 16062/52. Classes 78 (1) and 78 (4). [Also in Group V] Apparatus for lifting freshly pressed moulded articles from moulding presses, e.g. brick presses, with gripping jaws which are controlled by compressed air and which lift the moulded articles vertically from the bottom cam plate, bring them out of reach of the press and deposit them on a conveyer is characterized by the feature that the gripping jaws 6 are arranged on a common suspension frame 8 which is pivoted at a peripheral point of toothed rollers 11 which roll on toothed cam tracks 14, the axles of the rollers being fixed on a second frame 13 which is moved by a crank gearing 16, 20 and the cam tracks being shaped in such a manner that the gripping jaws first perform a vertical upward movement which effects the lifting, then a movement which brings the moulded articles out of reach of the press and finally a vertical downward movement which deposits the articles on the conveyer belt 15. The drive for the apparatus is taken from the moulding machine (which preferably comprises several moulds with double vertical plungers) through a chain 23, which drives a shaft 24 from which are driven a shaft 21 and, through a clutch 49, 50 a shaft 54 which drives the conveyer. Thus the mechanism operates in synchronism with the press. The track 14 is so shaped that, as the frame 13 runs along it, the suspension frame 8 is moved along a path including an initial vertical movement w-x, Fig. 2, in which the article is lifted off the press ram, and a final vertical movement at z, in which the article is deposited on the conveyer. The gripping jaws 6 are fluid-operated by cylinders 35, the two members of each pair of jaws being moved together through parallel linkage when shafts 38, 41 are rotated by the movement of the pistons in the respective cylinders 35. Each separate gripping device has its own piston drive, a showing the operating mechanism, b the articles being gripped and c the position before gripping. The jaws may be shaped to fit the article to be removed and may have renewable facings of felt or rubber; they may also carry symbols for stamping marks on the moulded articles. The top of the lower press ram may also be profiled for a similar purpose. The clamping pressure is adjustable by valves 34, for the individual pairs of jaws, and by an excess pressure valve 28 attached to the fluid-pressure reservoir. The pump 26 for supplying the fluid pressure is driven from the shaft 24 and the movement of the frame 13 is derived from the shaft 21 through crank rods 16. Each crank drive includes a spring 18, which takes up the movement of the crank when the frame 13 is held stationary by a stop 22. The frame 13 is stationary in the position corresponding to the instant when the moulded articles have been lifted out of the moulds by the rams, and at this instant a cam 29 opens a valve 30 and the fluid pressure is caused to bring the jaws 6 together on the article. As the cranks driving the rods 16 continue their movement the suspension frame 8, carrying the jaws gripping the articles, moves along the path w to z, Fig. 2. At the point z the conveyer is momentarily stopped, to allow the article to be deposited, by the action of a cam 47 on a bell crank 48, which disengages the driven element 49 of the clutch from the driving element 50 and brings it into contact with a brake disc 51 ; also the valve 30 is released and a valve 44 opened, by a cam 43, to allow pressure fluid to return to the reservoir, the articles thus being released by the gripping jaws under the action of return springs 46. It is stated that, instead of hydraulic or pneumatic operation, electrical or magnetic operation may be used, or that the gripping jaws may be operated mechanically by cables or linkages.