GB378816A - Improvements in or relating to presses for producing tubes particularly of cement - Google Patents

Abstract

378,816. Moulding concrete &c. pipes. GRABER & WENING, Neftenbach, Switzerland. March 10, 1932, No. 7218. Convention date, Feb. 1, [Class 87 (ii).] In apparatus for making cement tubes in which the core comprises a rotating piston fitted with projecting helical ribs which exert pressure on the cement and thus raise the core progressively in the mould as more material is fed in, the motor for rotating the core is mounted on the movable framework and moves up and down with the core. In the illustrated form the pipe A is formed in the mould 17 by the series of ribs 33 on the rotating core or piston 11. The piston rod 10 is journalled in a sliding frame 2 carrying the motor 5 and a worm transmission-gear 6, the lowest bearing being encased as at 14 to protect it from the falling concrete. The frame is counterbalanced partly by four chains 18, 19, Fig. 3, connected to a weight 24 and partly by weights 28 carried by ropes secured to pulleys 25. Rotation of the shaft 22 through the medium of the handle 32 and chain gear 29, operates the ropes and chains to raise or lower the frame and piston at will. The tapered ring 37, forming the lower end of the mould, is carried by a wheeled table running on channel rails 39 and fitted with racks 40 so that it can be run laterally out of the machine to deliver the moulded pipe by operating the hand-wheel 44 connected to the pinions 41 by a chain drive. A ring or table 45, which receives the surplus moulding material displaced by the upward movement of the piston, is provided with four toothed wheels 52 engaging corresponding racks on the framing and all operated simultaneously by worm gear rotated by the hand-wheel 46. In operation the empty mould is run into the machine by operating the handle 44, and the piston lowered to the bottom of the mould by operating the handwheel 32. The plate 45 then is lowered on to the top of the mould by operating the hand-wheel 46. The motor 5 then is started. At the conclusion of the operation the piston is raised still more by operating the hand-wheel 32 until it is freed from the mould, and the plate 45 then raised before the mould is run out of the machine again. The piston is fitted with renewable wearing rings 35, 36.