Hydraulic platform and level correcting control system
AssigneeMobil Oil Corporation
InventorClarence C. Hon
Life of this patent
Estimating the term…
Abstract
A hydraulic platform and level correcting system used for a wide variety of lifting applications that require a steady, level lift in order to avoid damage to the lift and/or an object being lifted. The hydraulic platform is controlled by an electrohydraulic control system which includes a hydraulic pump under the control of an electric control circuit to provide the lifting force necessary for hydraulic platform operation as well as a device for automatically correcting the level of the hydraulic platform.
Claims23
A hydraulic lifting platform utilizing an electrohydraulic control system comprising
- a pair of double acting hydraulic actuating means for providing the lifting force for said platform,
- control circuit means for driving said hydraulic actuation means,
- at least one angular position detection switch, said control circuit means being responsive to said switch, said switch comprising an electrically conductive liquid switch for determining if said platform is tilting in any direction during normal operation and to terminate power to said control circuit means if said platform is tilting whereby platform operation is suspended, and
- a servomechanism which is responsive to said angular position detection switch for adjusting the level of the platform when a tilt is detected in the platform during normal operation and resuming the normal operation when the platform is level.
A hydraulic lifting platform utilizing a pair of double-acting hydraulic cylinders for lift actuation and having a level correcting system comprising:
- tilt detection means connected to said platform for suspending operation of said lifting platform when said platform tilts in any direction during normal operation, said tilt detection means comprising at least one electrically-conductive liquid switch;
- and servomechanism means for leveling the platform which is responsive to said tilt detection means and is actuated when the platform tilts and resumes the normal operation when the platform is level.
A hydraulic lifting platform utilizing a pair of double-acting hydraulic cylinders for lift actuation and having a level correcting system comprising:
- tilt detection means connected to said platform for suspending operation of said platform when said platform tilts in any direction;
- and
- servomechanism for controlling the level of said platform and raising or lowering said platform which is responsive to said tilt detection means;
- comprising, a pump for providing hydraulic fluid under pressure to said pair of double acting hydraulic cylinders to raise and lower said platform;
- motor means for driving said pump;
- and motor control circuit means for controlling said motor means by controlling the power to said motor means and which is responsive to said tilt detection means, said pump being a twin-positive displacement pump which provides hydraulic fluid and to said pair of hydraulic cylinders at constant and equal flow rates and volumes through first and second valve means.
Dependencies are inferred from the claim text.