US 4,375,781 AGranted

Double-acting hydraulic press

OwnerMichio Besshoinventor

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Abstract

In a double-acting hydraulic press: an outer press ram having a cylinder formed therewithin for the piston of an inner press ram, the inner and outer ram cylinders in communication with one another and the rams being subject to a common hydraulic actuating means, each ram carrying a separate and distinct tool at its forward face, and means controllably feeding pressurized hydraulic fluid to an intermediate section of said inner ram cylinder, whereby to control the effective hydraulic force applied to said inner ram and the tool thereof.

Claims3

Dependent claims

An hydraulically actuated press comprising:

a support frame including a first cylinder therein;
ram means having one end portion disposed within said cylinder and comprising a first piston;
a bore structure extending axially completely through said ram means, said bore structure being of restricted diameter at each end to thereby define an intermediate larger diameter bore section comprising a second cylinder;
a second piston, the second piston being disposed in said second cylinder and having one end operatively associated with the structure forming one of said restricted diameter bore ends, through which said second piston is exposed to the first cylinder and which said one restricted bore end functions as a stop means for said second piston;
said second piston being of reduced diameter excepting for said one end and the reduced diameter portion being reciprocally disposed in fluid-tight relationship in the second of said restricted diameter bore ends;
a tool element extending from a free end of the reduced diameter portion of the second piston and having a path of motion extending from within the ram means to through a face of the second end of the ram means;
said face comprising a tool means operatively associated with said tool element;
means to feed pressurized hydraulic fluid to said first cylinder, whereby to exert motive force to said first piston and, through said one restricted diameter bore end, to impart motive force to said second piston;
means to controllably pressurize and feed hydraulic fluid to the second cylinder at a location coinciding with the reduced diameter section of the second piston whereby the motive forces to said tool element may be variably apportioned;
means on said frame to support material to be operated on by each of said tool means and tool element;
and
means, separate and distinct from the afore recited hydraulic feed means to return said ram and second piston to an initial disposition following a working stroke.

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Dependencies are inferred from the claim text.

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Abstract

An hydraulically actuated press comprising:

a support frame including a first cylinder therein;
ram means having one end portion disposed within said cylinder and comprising a first piston;
a bore structure extending axially completely through said ram means, said bore structure being of restricted diameter at each end to thereby define an intermediate larger diameter bore section comprising a second cylinder;
a second piston, the second piston being disposed in said second cylinder and having one end operatively associated with the structure forming one of said restricted diameter bore ends, through which said second piston is exposed to the first cylinder and which said one restricted bore end functions as a stop means for said second piston;
said second piston being of reduced diameter excepting for said one end and the reduced diameter portion being reciprocally disposed in fluid-tight relationship in the second of said restricted diameter bore ends;
a tool element extending from a free end of the reduced diameter portion of the second piston and having a path of motion extending from within the ram means to through a face of the second end of the ram means;
said face comprising a tool means operatively associated with said tool element;
means to feed pressurized hydraulic fluid to said first cylinder, whereby to exert motive force to said first piston and, through said one restricted diameter bore end, to impart motive force to said second piston;
means to controllably pressurize and feed hydraulic fluid to the second cylinder at a location coinciding with the reduced diameter section of the second piston whereby the motive forces to said tool element may be variably apportioned;
means on said frame to support material to be operated on by each of said tool means and tool element;
and
means, separate and distinct from the afore recited hydraulic feed means to return said ram and second piston to an initial disposition following a working stroke.

9 more elements