GB446279A - Improvements in hydraulic plate holders for pressing, stamping and like machines - Google Patents

Abstract

446,279. Cupping - press. BERLINERFURTER MASCHINENFABRIK H. PELS & CO. AKT.-GES., 1, Schwerbmerstrasse, Erfurt, Germany. Oct. 23, 1934, No. 30661. Convention date, Oct. 26, 1933. [Class 83 (iv)] The resistance of the draw ring 5 or buffer of a press can be varied in accordance with the kind of work done on the workpiece 6 by altering the pressure required to open the release valve 15 by interposing an adjustable wedge 17 to alter the compression of the spring 19 on the valve. When the die 4 approaches the work 6, the rod 33 on the ram lowers the ejector plate 32 to position 32a and continuing movement cups the work 6 and depresses the piston 13 which thereby forces liquid from the chamber 26 through valves 15 to an overflow chamber 28 where it makes room for itself by depressing the spring pressed piston 29 forming the bottom of the chamber 28. A manometer 34 shows the resistance pressure in the chamber 26. On the return stroke the spring 30 is free to press piston 29 up to deliver back through the valve 16 to the chamber 26 the same quantity of liquid that was forced therefrom during the working stroke. Also after a delay the ejector plate is raised to strike the piston rod 14 and raise the draw ring 5 to strip the work. The position of the wedge in the valve stem 15a is varied as desired by rotating the reversed sleeve 25 thus raising or lowering the ring 23 carrying brackets which adjust wedge 17. The wedge may be replaced by a screw-adjusted cone.