Patent GB-748464-A (GB)
Title: Semi-automatic machine for manufacturing blocks of cementitious material or the like
IPC: B28B1/087
Filed: 1953-09-25
Abstract: 748,464. Compression moulding machines for making concrete blocks. ROSA, A. Sept. 25, 1953 [Sept. 27, 1952], No. 26490/53. Class 87(2) In a compression moulding machine for making blocks of cementitious material, fed from a hopper, in a vertically reciprocable open mould and incorporating vibrating means, the vertically reciprocable plunger 2 is also horizontally reciprocable with the hopper 7. The open mould 3 is supported from bars 32 carried by rods 30, Fig. 6, through springs 33. The mould is lowered on to its pallet 4 by the rotation of pinions 35 which engage racks 31 on the rods 30. To cause this movement a lever 53 is moved to the right. Fig. 2, and, through linkage shown in Fig. 3, engages a clutch 48 whereby the pinions 35 are driven through gearing from a pulley 39 which is belt-driven from a motor 36. When the mould has reached its lowest position a projection 58 from one of the rods 30 strikes a lever 62 on the shaft 52 of the lever 53 and returns it to its neutral position, so disengaging the clutch 48 and interrupting the drive to the mould-lowering device: A carriage 1 is then moved by hand to the right, Fig. 1, rolling along co-linear guides 10, 10<1>, and the hopper 7 attached to the carriage is brought beneath a container 6 holding cementitious material. This movement of the carriage 1 operates levers 85, 86 to cause the rotation of a shaft 89 which, through linkage terminating at 92, Fig. 6, moves a pin 93 to the left which enters a slot in a lever 96 on the shaft 52. The lever 53 is therefore locked in its neutral position and the mould 3 held against upward movement while the hopper 7 is above it. The bottom 23 of the container 6 is opened by a bell-crank lever 26 and a charge of cementitious material drops into the hopper and thence fills the mould. A lever 65 is then moved to the right, Fig. 2, and, through linkage 68, 69, Fig. 3, engages a clutch 64 to cause the drive from the pulley 39 to be transmitted to a pulley 71 which drives, through a belt 72, vibrators which rotate in an oil bath attached to the vibrating platform 5. The platform 5 is supported on four rods each surrounded by two springs so arranged that one is compressed by downward movement and the other by upward movement, their pressure being adjustable by screwed collars. Vibration of the mould is maintained for a short time to settle the material in it, the filling being completed in two stages. The carriage 1 is then pulled back to the left, Fig. 1, a scraper on the bottom levelling the material, until the plunger 2 also carried by the carriage is over the mould 3, this movement causing the pin 93 to leave the slot in the lever 96 and free the mould for upward movement. A lever 14 is then moved to the right, Fig. 1, towards and then past its dead-centre position, whereby a crank actuates a connecting rod 16 and causes movement to be transmitted to arms 17 which first compresses springs 12, Fig. 8a, and then allows them to expand and in doing so to exert a resilient downward force on the plunger 2 through their action on adjusting nuts 20 into which are screwed rods 11 which carry the guides 10<1> which enter grooves 13 in legs depending from the carriage 1. The lever 65 is operated to vibrate the mould. When the plunger has reached its lowest position a projection 102<1>, Fig. 9, from an arm 17 comes below the level of a tooth 102 projecting from a rod 103 which is snapped over it by a spring 105 to lock down the plunger. The lever 53 is then moved to the left. Fig. 2, thereby engaging the clutch 49, Fig. 3, and causing the pinion 35 to raise the mould, the plunger, being locked down, now acting as a stripper by pressing on the moulded material. As the mould continues to rise a cam 106 on the rod 30, Fig. 9, meets the edge 107 of a groove in the rod 103 and moves it to release the projection 102<1>, at which the springs 12 cause the plunger to rise. The moulded block is then left on the pallet 4. A holder 83, Fig. 12, is inserted beneath the pallet, embracing cross members 84 beneath it, and the pallet and moulded block are removed in the holder. If desired the rod 103 can be released manually, by depressing a knob 109. The machine may be modified to allow the pallet and moulded block to be removed from the opposite side, i.e. the right in Fig. 1, leaving the operator at the control levers undisturbed. The springs 12 may be carried by members separate from the vibrating platform 5, to prevent the transmission of vibration to the plunger. In another modification, Fig. 15, to facilitate stripping when thin-walled blocks are moulded, cores 111 are carried by an upper member 112, joined to the rods 30, from which projections 113 extend downwards outside the mould 110 and have slots 114 to receive projections 115 from the mould walls. As the rods 30 rise after the moulding operation the cores are drawn out of the material while they move the distance of the slots 114, and then the mould 110 is lifted, owing to the bottoms of the slots meeting the projections 115, this two-stage stripping action reducing the initial pressure on the moulded,block.