Patent GB-623016-A (GB)
Title: Power operated hydraulic sealing and crimping machine
IPC: B65B65/02
Filed: 1946-04-16
Abstract: 623,016. Hydraulic presses. SALFISBERG, L. L. April 16, 1946, No. 11628. Convention date, May 17, 1945. [Class 69 (ii)] In a press having a mechanism for closing relatively movable jaws 3, 4 comprising main and auxiliary jaw-actuating means, the latter of which initially closes the jaws under a light pressure while the first thereafter continues the jaw-closing operation under relatively high pressure, the main and auxiliary jaw-actuating means include a main and an auxiliary liquid-operated piston-and-cylinder device respectively, the main device being connected with the jaws by way of a toggle linkage 11, 13, operation of the auxiliary device 18 moving the toggle joint toward the position in which the toggle linkage is locked, whereby the jaws are initially closed, subsequent operation of the main device 15 applying pressure to the jaws through the toggle linkage with the linkage substantially in its locked position. An electric motor 31 (Fig. 2) drives a pump 24 which delivers liquid from a reservoir 23 into passages 35, 36, 37 and 38 (Fig. 4) until a spring- loaded power piston 40 is raised to uncover a port 80 communicating with the reservoir. The pressure of the liquid is thus controlled by a spring 41, the loading on which is regulated by rotating a cap 90. Liquid from the passage 37 also passes into a chamber 66 (Fig. 3) and thence through a tapered needle-controlled port 63 of a timing valve, a passage 62, an annular groove 61 in a control piston 56 and passage 58 into a cylinder 42 to raise a piston valve 43 to shut off passage 38 from a passage 72 leading to the piston-and-eylinder devices of. the jaw-actuating means. To close the jaws, a starting valve (not shown) in a cylinder 46, Fig. 3, is pushed inwardly and then released so that it returns to its normal or closed position under spring pressure. Whilst the starting valve is in its inward position it permits liquid from passage 37 to flow through passages 52, 53 and 54 to raise the spring-loaded control piston 56 so that an opening 59 therein communicates with the passage 58. Liquid under piston valve 43 can then exhaust through passage 58 and a vertical opening 60 in control piston 56, passage 68 and passage 69 which leads to the reservoir 23. A spring 44 lowers the valve 43 to establish communication between passages 37 and 72 so that pressure liquid passes into passages 73 and 74 to raise the auxiliary operating piston 18 to close the jaws and move the toggle linkage to its locked position, the linkage comprising a bell-crank lever 13 pivoted to the main piston 15 at 14 and to the link 11 at 12, and having rollers 17 and 19. Continued movement of the piston 18 allows a reduced portion 86 to establish communication between passage 74 and a recess 85 in the main operating piston 15, whereupon the liquid pressure is applied to the bottom of the latter to force it upwards to close the jaws tightly. Since the starting valve has been allowed to close, the passages 52, 53, 54 are opened to exhaust and the spring 57 of the control piston 56 lowers it so that pressure liquid again flows from passage 37 and chamber 66 through the port 63, passage 62, groove 61 and passage 58 into cylinder 42 to raise the piston valve 43. The rate of flow through the port 63 is controlled by adjusting the needle 64, and hence a predetermined time elapses before the valve 43 is returned to its upper position in which it cuts off supply of liquid to the operating pistons 18, 15 and allows the liquid under these pistons to flow through passages 74, 73, 72, 68 and 69 to reservoir 23, whereupon the spring-loaded member 20 acts on the toggle linkage to open the jaws. Liquid raising the piston 15 also raises a spring-loaded piston 118 to actuate a counter 114. The starting valve may be connected to the front of the jaws in such a manner that the valve is pushed inwardly as the operator inserts work into the jaws.