GB769739A - Improvements in platen-type presses - Google Patents

Abstract

769,739. Stamping. CLARK, J. D. April 1, 1955, No. 9639/55. Class 83 (4). [Also in Groups V, VIII and XXIX] An hydraulic press for shaping metal sheets comprises a stationary platen co-operating with a platen carried by a piston of non-circular cross-section, the platens having the same crosssection as the piston. The piston may have a central opening or be irregular in cross-section, and the surface of the platens may have a compound curvature. The movable platen may be yieldable to conform to the face of the stationary platen. Sealing means are provided at either the outer end of the cylinder or the inner end of the piston. The press shown in Fig. 4 comprises a piston 180 of rectangular section mounted in a chamber 177 in the lower end of a shell 175. A platen 192 carried by the piston co-operates with a platen 198 fast with the shell 175. A chamber 176 above the platen 198 communicates with the chamber 177 through a conduit 179 and serves to reinforce the platen. A multiple-opening press is shown in Fig. 1 and comprises a fixed platen 128 with a reinforcing tank 122, a movable platen 116 and intermediate platens 130. The platen 116 is carried by a piston 104 of rectangular section, the walls of the piston being reinforced by plates 112. The piston is mounted in a cylinder 99 of rectangular section but with rounded corners, the cylinder being mounted within, and communicating with, a tank 90 which also communicates with the tank 122. The platen 116 is prevented from tipping during an idle stroke by means of sprockets 151, 154, 163, 165 carried by shafts 152, 155, 162, 166 mounted on the press frame, the sprockets co-operating with chains 153, 164 which are fast with the piston 104. The press frame is reinforced by tension plates 167, 168, 169 and compression plates 170, 171.