Hydraulic drive mechanism
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Aug 21, 1990
Grant Date -
N/A
app pub date -
Mar 3, 1989
filing date -
Apr 7, 1987
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
Hydraulic drive mechanism for a machine element with rapid feed movement and under-load feed movement, comprising a double-acting hydrocylinder power drive and a pressure switching valve responding to the pressure at least in a larger operating chamber of the hydrocylinder when the pressure in the operating chamber exceeds a threshold value higher than 1/4 of the operating pressure of the pressure supply source, but lower than half the operating pressure thereof, switches to under-load feed operation and, when the pressure in the drive pressure or operating chamber falls below the threshold value, switches back to rapid feed operation. The pilot valve for the main control valve is equipped with two windings effective in opposite directions. A switching device is included which, in a position- or time-controlled fashion, excites the second control winding, and a return signaling stop is provided which brings about, in the point of reversal of the piston movement of the hydrocylinder on the workpiece side, a mechanical switchover of the pilot valve into the position required for the retraction movement.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully