GB227483A - Improvements in or relating to hydraulic presses - Google Patents

Abstract

227,483. Greenwood & Batley, Ltd., and Barker, J. H. Sept. 14, 1923. Extrusion machines.-An extrusion press for cordite &c. comprises a main inverted hydraulic cylinder 15, Fig. 2, the ram of which carries a plunger 26 adapted to press cordite from a cylinder 11 through a die 56, pressure liquid being forced into the cylinder 15 by a ram 24 working in a cylinder 18 of smaller diameter than the cylinder 15. The ram 24 is screwed at its lower end, so that it may be reciprocated from a shaft capable of being driven in opposite directions through a worm, worm-wheel and nut. The cylinders 11, 15, 18 are carried by cross-pieces secured to pillars 4. The cordite &c. is placed on the die 56 which is raised by means of a third hydraulic cylinder 72, until interrupted screw threads on the die-holder 57 engage similar threads at the lower end of the cylinder 11. The die-holder is then rotated to lock it in position by means of rack bars engaging a mutilated pinion on the holder. The driving shaft is then rotated to raise the ram 24, thus causing the plunger 26 to be depressed and the cordite to be extruded on to a conveyer 66. The ram 24 rises until a rod 137, Fig. 14, has been lifted by a pin 144 and arm 142 to cause a collar 166 to lift a lever 159 and so cause a belt-shifter 193 to move a belt from a fast pulley 191 to a loose pulley 190. The die is then released from the cylinder 11 and lowered. Should it then be desired to inspect the lower end of the plunger 26, the rod 137 is partially rotated, so that the arm 142 is moved out of the path of the pin 144 and the driving shaft is again rotated, being stopped when the pin 144 contacts with an arm 141 on the rod 137. The ram 24 is moved downwardly by rotating the driving shaft by a cross belt on a fast pulley 189, the downward movement continuing until a pin 145 operates a lever 147 to cause a belt-shifter 192 to move the belt on to a loose pulley 188. The plunger 26 and its ram are returned to their upper positions by counterweights; should the plunger 26 have seized, it may be raised by substituting a cylindrical steel bar for the die. The rod 137 is capable of being lifted automatically to stop the driving shaft on the occurrence of excessive pressure in the cylinder 15, by means of a plunger positioned under the lower end of the rod and acted on by the pressure in the cylinder.