Holddown mechanism for a dockboard
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
May 8, 1990
Grant Date -
N/A
app pub date -
Oct 14, 1988
filing date -
Oct 14, 1988
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
An improved dockboard mechanism for a mechanical dockboard. The dockboard includes a frame that is mounted on a loading dock and a ramp is hinged at its rear end to the frame and is movable between a generally horizontal cross traffic position and an upwardly inclined position. The ramp is biased to the upwardly inclined position by a counterbalancing spring. The holddown mechanism includes a cylinder connected to the ramp and a piston is slidable within the cylinder and carries a piston rod which is connected to the frame. The piston is provided with a longitudinal passage which is closed off by a valve member, and an actuating rod is connected to the valve member and extends outwardly of the cylinder. Movement of the rod will open the valve member to permit extension of the piston rod with respect to the cylinder to enable the ramp to pivot upwardly by the counterbalancing spring.
First Claim
Other Claims data not available