Patent GB-1155767-A (GB)
Title: Self Feed Ram for Extrusion Equipment
IPC: B29C48/10
Filed: 1967-02-10
Abstract: 1,155,767. Feeding rubber to an extruder. UNIROYAL Inc. 10 Feb., 1967 [1 Aug., 1966], No. 6482/67. Heading B5A. Rubber stock in strip or thread form is fed to a hopper 21 on an extrusion machine which has its barrel 11 and screw 13 connected with the hopper by a feed throat 24 in which is reciprocably mounted a ram 23, means 29 guiding and feeding stock to the hopper being responsive to movement of the ram to feed stock in front of the ram during retraction thereof. The guiding and feeding means directs strip (34) from a supply (35), Fig. 1 (not shown) over a guide roller (37) and then between a pair of spaced apart guide rollers 47, 53 to four spaced sprockets 60, Fig. 2 (not shown), on a shaft 61 driven by a clutch (65) operated by a vertical rod 67, an endless chain 71 passing around each sprocket 60. These chains guide the stock between respective pairs of cutting rolls and back-up rolls 81, 82 and 87, 88 which pleat the stock prior to its downward descent, and then between pairs of guide rolls 93, 94 and 97, (98), the latter part having their axes perpendicular to those of the former. The stock is now of reduced width and is gathered by rolls 99 (100) prior to passage through a squeeze roll 104 and drive roll 121, the roll 104 being swung inwardly and outwardly by a pneumatic cylinder. The roll 121 is prevented from clockwise revolution by a clutch (138), Fig. 8 (not shown). Rubber stock caught between the ram 23 and a bottom wall 201 thereof escapes through a bottom opening 227 to obviate jamming. The extrusion machine 10 is controlled by a pneumatic circuit, Fig. 16 (not shown) and air pressure releases a brake (147) to rotate the roll 121, air pressure simultaneously effecting operation of the rod 67 to feed stock to the cutting rolls 81, 87 while the plunger 215 of the ram 23 is actuated by a pneumatic cylinder 235 and stock is fed in front of the plunger 215 during retraction thereof until in a fully retarded rear position it trips a switch (241) reversing the air flow to advance the feed plunger. Advance of the plunger continues until it contacts the stock in the hopper whereon for a constant air pressure in the cylinder 235 movement of the piston rod 234 is slowed. Air pressure exhausting from the pneumatic circuit through a bleed valve (250), Fig. 16, thus gradually decays until at a predetermined point air is admitted to the brake (147) to brake the feed roll 121 and when the stock is carried away by the screw 13 the plunger 215 trips a forward trip (243), the screw 13 thereby being fed intermittently to a constant predetermined level. A second embodiment Figs. 17-22 (not shown), is designed for feeding a narrow strip of stock or multiple strips of raw stock or stock in strand or thread form to an extrusion machine. The ram plunger (215a) is reciprocated by an air cylinder (235a), the stock being fed over a guide roller (299) and between rolls (292), (293), thence over roll (287) down the front of the ram plunger (215a), over guide rolls (282) and into the hopper (21a). An endless belt (325) drives the stock over the rollers (282) during forward movement of the plunger, the rollers (282) being disposed on top of the plunger.