Patent GB-264295-A (GB)
Title: Improvements in or relating to hydraulic presses
IPC: B30B11/26
Filed: 1925-12-15
Abstract: 264,295. Greenwood & Batley, Ltd., and Barker, J. H. Dec. 15, 1925. Extrusion machines.- A double-acting hydraulic press for the extrusion of cordite &c, comprises a central horizontal press cylinder, having a piston provided with selfc e n t r i n g extruding plungers, pressure liquid being supplied alternately to opposite ends of the cylinder by means of a ram reciprocated in a pair of cylinders. The cordite &c. is placed in heated or other containers, from which it is forced through dies detachably carried by blocks fixed to slidable saddles. Automatic controlling and safety means are provided. In the form shown, jacketed containers 34, Fig. 2, are mounted in members 19 disposed on each side of the central cylinder 3 mounted in a member 2, the members 2, 19 being connected by bolts 20 and distance pieces 21. Each extruding plunger is connected to the piston rod by means of a member 13 having screwed studs received in screwed recesses, the threads being cut to allow relative transverse movement. A die 74 is connected to a hollow block 52 by a bayonet-joint fitting, the block being rotatably mounted on a slidable saddle 50, and provided with interrupted screw threads adapted to engage similar threads 72 formed in an extension 41 of the container 34. The pressure-producing apparatus comprises two opposed cylinders 87, 88, Fig. 11, connected to opposite ends of the press cylinder, and a ram-member reciprocated therein by a screw-and-nut and worm gearing from a shaft having a fast pulley 98 and loose pulleys 99, 100, the position of oppositely moving belts being controlled by forks operated by slots 106, 107 in a movable bar 105, the slots being so formed that one belt is moved on to its loose pulley before the other is moved on to the fast pulley. When the apparatus is to be set into operation, the bar 105 is moved by link &c. connections from a hand lever to bring one belt on to the fast pulley, a lever 154, Fig. 14, being simultaneously moved into the position shown, or into that of the line 202, so that one of a pair of catches 169, 170, Fig. 13, engages a recess 167 or 168 in the segmental upper end of the lever. When the press piston reaches the end of its stroke, a projection 187 on one of the members 13 engages one of a pair of adjustable tappets 177, 178, and moves a rod endwise so that a double cone 176 lifts the engaging catch. A weight 1.95 or 196 then reverses thel position of the lever 154 and the belt-shifting mechanism is operated, so that the movement of the press piston is reversed. If it is desired to allow the press piston to travel farther, a set screw 184 is loosened. and the rod 151 is turned so that the tappets 177, 178 are moved out of the path of the projections 187. Means for stopping the action of the pressureproducing means and the press, in the case of over-running or excess pressure, comprise rods 119, Fig. 24, projecting into the cylinders 87, 88. When a rod 119 is moved axially against the action of springs 126, a cone 121 operates an arm 134 so that, through link &c. connections, a U- shaped lever 203 is operated to lift the catches 169, 170. Springs attached to hooks 190, 191 then move the lever 154 into its vertical position, the belt shifting means being thereby moved so that both belts are on the loose pulleys. Specification 227,483 and 252,048 are referred to.