Patent GB-306955-A (GB)
Title: Improvements in machines for producing pressed moulded articles
IPC: B30B15/30
Filed: 1929-02-23
Abstract: 306,955. St³dli, H. Feb. 29, 1928, [Convention date]. Stationary-mould machines; feeding ; strain, preventing. - An hydraulic press for moulding articles, e.g. boxes from powdered material such as sawdust mixed with a binder, comprises a beam loosely resting upon the movable part of the press and adapted to eject the finished articles as the press returns to initial position, charging apparatus for the moulds and controlling mechanism influenced by abutment means. As shown, the press comprises a cylinder 2, moving over a fixed hollow piston, which carries a mould 7 and supports loosely a beam 11 carrying bottom plungers; the cylinder co-operates with fixed upper plungers 13 and with a feed slide 73. The material is maintained under heat and pressure for a. predetermined time, gases being withdrawn through channels in the upper plungers and a tube 22. A shaft 37, driven from a motor 39, operates timing mechanism for the press, and through a clutch, actuates an aligned shaft 37<1> carrying cams which operate the weighing and feed devices and the press valves. Material is supplied from a hopper 31, fitted with rotary members 33 carrying bars 34, to shoots 43 leading to weighing-vessels 57 mounted upon pivoted beams 56 carrying members 69 adapted to engage contacts 70 to energize solenoids 54 and release levers 46 carrying flaps to cut off the supply from the hopper. The vessels 57 are furnished at the bottom with hinged doors which are opened simultaneously by a lipped member 63 carried by a lever 65 actuated through a rod 66. A member 50, actuated through a rod 49, re-sets the levers 46. The weighted material passes through shoots 71 into compartments in a feed slide 73 reciprocated along guides 74 by a lever 75. The slide 73 is furnished with compartments adapted to register alternately with the shoots 71 and with the mould cavities. The compartments are closed by a plate 84 retained by a catch which is released, when the slide is over the moulds, by a slight upward movement of the mould acting through a member 78, link 79 and lever 80 whereupon the slide is retracted by a weight 85 to allow the material to fall into the moulds. During the forward movement of the slide 73, the member 78 pushes the previouslymoulded articles A onto a delivery shoot 83. After withdrawal of the slide, the cylinder 2 rises and the material is compressed against the upper plungers 13, heat being applied by electric heaters within the mould. Upon completion, the cylinder 2 is lowered until it contacts with stop members 19, ejection being effected by contact of the beam 11 with stops 20. The press is supplied with low and high pressure water through valves 27, 25 respectively and is exhausted through a valve 24. The shaft 37 drives the member 33 through a chain 36 and actuates a timing-ratchet 109 through a cam and pawl. In action, low pressure water raises the cylinder 2 until an abutment 125 engages a member 122 and, through a rod 121 and lever 114 opens the valve 25. After a predetermined interval, a stop on the ratchet 109 engages a lever 126 which opens the exhaust valve 24 through a rod 127; a second stop deflects a lever 117 to close the valve 25 against spring action. The lever 126 is also connected to a. rod 128 carrying a stop 129 and held by a spring 132 in the path of an abutment 130 on the cylinder; the rod 128 is connected to the slide 73 and in the event of the cylinder rising while the slide is over the mould, the exhaust valve is opened by engagement of the parts 129, 130. Upon descent of the cylinder 2 an abutment engages one arm of a three-armed lever of which the second arm releases a holding-detent and frees the ratchet 109 which is returned by a weight 115; the third arm releases the clutch and causes engagement of the shaft 37 with the shaft 37<1>. The shaft 37<1> carries cams 133, 136, 139 and 141 actuating respectively the lever 75, rods 66 and 49 and a lever 145 controlling the valve 27. After a part revolution the clutch is disengaged by a second clutch-controlling member actuated by an inclined abutment on the cylinder 2.