Lift assembly
First Claim
1. A lift assembly comprising:
- a base member;
first and second lift platforms operatively connected to the base member;
means for selectively moving the lift platforms toward and away from the base member; and
means for synchronizing movement of the first and second lift platforms relative to the base member, the synchronizing means including means for sensing height differential between the lift platforms including first and second arms interconnecting the lift platforms with the base member, a lateral member operatively engaging one of the first and second arms and extending between the first and second arms, and means for sensing relative rotational movement between the arms indicating height differential between the platforms.
1 Assignment
0 Petitions
Accused Products
Abstract
A lift assembly adapted for large vehicles includes first and second lift platforms selectively raised and lowered relative to a base member. Fluid actuated support arms are interposed between the lift platforms and the base member to define a generally trapezoidal arrangement. Segmented bearings are interposed between opposite ends of the support arms and the lift platforms and base member to accommodate tolerance stackup. The lift assembly also includes a sensing assembly that determines if a height differential exists between the lift platforms. If a height differential is sensed, movement of one of the lift platforms is altered to correct the situation. If too great a differential is sensed, further movement of the platforms is terminated. A locking arrangement maintains the lift platforms elevated relative to the base member. A sensing arrangement determines whether the locking arrangement is properly oriented and whether the load is applied from the lift platforms. Lift jack assemblies are provided to selectively lift the vehicle relative to the lift platform. A multiplexing arrangement is provided to synchronize movement between the lift jack assemblies. Further, the lift jack assemblies may be comprised of single acting fluid cylinders that are retracted with a bidirectional pump.
57 Citations
35 Claims
-
1. A lift assembly comprising:
-
a base member; first and second lift platforms operatively connected to the base member; means for selectively moving the lift platforms toward and away from the base member; and means for synchronizing movement of the first and second lift platforms relative to the base member, the synchronizing means including means for sensing height differential between the lift platforms including first and second arms interconnecting the lift platforms with the base member, a lateral member operatively engaging one of the first and second arms and extending between the first and second arms, and means for sensing relative rotational movement between the arms indicating height differential between the platforms. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A lift assembly comprising:
-
a base member; a lift member adapted for selective movement toward and away from the base member; first and second support arms interconnecting the base member and the lift member and defining a generally trapezoidal arrangement; means for accommodating tolerance stackup such that any two adjacent sides of the generally trapezoidal arrangement is substantially equal to the remaining two adjacent sides. - View Dependent Claims (20, 21, 22, 23, 24)
-
-
26. A lift assembly comprising:
-
a base member; a lift member adapted for selective raising and lowering relative to the base member; means for selectively locking the lift member at a preselected height above the base member; and means for sensing that said locking means is properly oriented and that the lift member is loaded, the sensing means including a lock bar having a series of notches therein adapted to receive a lock arm interposed between the lift member, and a fluid actuator that selectively rotates the lock bar. - View Dependent Claims (25, 27)
-
-
28. A lift assembly comprising:
-
a base member; a lift member operatively connected to the base member; means for selectively moving the lift member toward and away from the base member; a bar having plural notches spaced in non-linear relationship for receiving a lock arm associated with the lift member and provide uniform incremental lift heights of the lift member; and means for indicating orientation of the notched bar for receipt of the lock arm.
-
-
29. A lift assembly comprising:
-
a base member; a lift member; first and second arms linking the base member and lift member together; and each arm connected too the lift member through a segmented bearing that permits complete transfer of compressive and tensile forces through and accommodates tolerance build up between the arms, base member and lift member. - View Dependent Claims (30, 31)
-
-
32. A lift assembly comprising:
-
a base member; a lift member operatively connected to the base member; means for selectively moving the lift member toward and away from the base member; first and second lift jack assemblies associated with the lift member for raising and lowering loads relative to the lift member, the lift jack assemblies being operated by first and second electric motors; and means for rectifying and alternating current into a reduced voltage, pulsating direct current to synchronously operate the first and second motors.
-
-
33. A lift assembly comprising:
-
a base member; a lift member operatively connected to the base member; means for selectively raising and lowering the lift member relative to the base member; a lift jack assembly having a single acting fluid cylinder operated by a bi-directional pump, the lift jack assembly being associated with the lift member for raising and lowering loads relative to the lift member; and means for operating the pump in reverse without cavitating the pump to retract the fluid cylinder. - View Dependent Claims (34)
-
-
35. A lift assembly comprising:
-
a base member; first and second lift platforms operatively connected to the base member; means for selectively moving the lift platforms toward and away from the base member; and means for synchronizing movement of the first and second lift platforms relative to the base member, the synchronizing means including a shaft extending between the lift platforms and means for sensing height differential between the lift platforms wherein said synchronizing means equalizes the lift platforms if the height differential is limited and terminates in movement of the lift platforms if the limited height differential is exceeded.
-
Specification