Hydraulic unit for driving a tool
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Apr 21, 1992
Grant Date -
N/A
app pub date -
Sep 26, 1990
filing date -
Sep 28, 1989
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A hydraulic cylinder has a piston in it with a rod projecting out of the cylinder and connectable with a tool which is operable by movement of the piston rod. A high pressure space is defined in the cylinder at one side of the piston and a low pressure space is defined at the other side of the piston. A partition defines the other end of the low pressure space. A diaphragm on the other side of the partition defines an equalizing space between the diaphragm and the partition. A low pressure line is in communication with the low pressure space and with the equalizing space. A change over valve in the lines to both the high pressure space and the low pressure space enables connection of high pressure from a pump either to one space or to the other space in the cylinder while always permitting communication from the low pressure line to the equalizing space, the connection to the equalizing space is in the low pressure line between the change over valve and a non-return valve at the pump.
First Claim
Other Claims data not available