GB1255422A - Improvements in multi-story presses - Google Patents

Abstract

1,255,422. Presses. MOTALA VERKSTAD A.B. 24 June, 1969 [27 June, 1968], No. 31881/69. Heading B5F. The multi-platen press of Fig. 1 comprises a stationary platen 1 and movable platens 2-5 interconnected by a number, e.g. four, lever arm systems each comprising pivoted arms 6, 7 and rods 8 pivoted to the platens 5 and attached at their other ends to members 9 pivoted to the arms 6, said members preventing, during the pressing operation, overloading of the lever arm systems, and eliminating the effect of the weight of the platens. Each member 9, Fig. 2, comprises a cylinder 16 closed at its lower end by a part 17 with trunnions 18 by which the member is pivoted to an arm 6. A piston-rod 14 depends from the cylinder and is attached to the upper end of a rod 8, and a friction assembly comprising friction rings 10 with intermediate thrust washers 11 and end thrust washers 12, 13 is positioned between the piston-rod and cylinder. A piston 22 is urged against the assembly by pressure fluid from a source 33 and influences the force to be applied by the rod 8 to cause movement of the pistonrod and friction assembly relative the cylinder. Some pressure fluid bleeds through passages 27, 28 and fills cavities in the assembly and passes via a passage 29 to a tank 31. During initial press closure there is no movement of the pistonrod in the cylinder, but when the pressing operation begins, and during any drying of the material being pressed, relative movement may occur in response to differences in the thickness, quantity &c. of the material located between the various pairs of platens. If such relative movement during a drying period is undesired the upper end of each cylinder may be extended, Fig. 3, not shown, to receive a piston which bears down on to the upper end of the piston-rod and is subjected to pressure fluid; during the pressing operation such pressure fluid is not applied. Instead of a fluid actuated piston 22, a spring may act on the friction assembly. In a modification the piston-rod 14 may be connected to the lever arm 6 and the cylinder 16 to the rod 8, and the friction rings urged inwardly against the piston-rod.