Hydraulic actuator assembly with rotation restraint
OwnerBruce A. Helderinventor
Life of this patent
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Abstract
A hydraulic actuator assembly comprises a pair of hydraulic actuators having cylinders, pistons, and piston rods that are ganged together for extension of their respective piston rods in longitudinally opposite directions wherein at least one of the actuators comprises an anti-rotation mechanism that prevents rotation of the actuator assembly about its longitudinal axis. The anti-rotation mechanism comprises an axial anti-rotation rod rigidly attached to a cylinder having a non-circular cross-section slidably complementary to a non-circular aperture in a hollow piston rod. The piston rod can travel longitudinally along the anti-rotation rod, but is prevented from rotating by the non-circular cross-section.
Claims22
A hydraulic actuator assembly for moving a first object relative to a second object, comprising;
- a first hydraulic actuator having a first cylinder with a first longitudinal axis, and a first piston slidable within the cylinder and attached to a first piston rod for movement along the first longitudinal axis with respect to the cylinder;
- a second hydraulic actuator having a second cylinder with a second longitudinal axis, a second piston slidable in the second cylinder and attached to a second piston rod for movement along the second longitudinal axis with respect to the second cylinder, and a non-rotation mounting between the second piston rod and the second cylinder for non-rotational movement of the second piston rod about the second longitudinal axis;
- and
- a rigid mounting between the first cylinder and the second cylinder so that the first longitudinal axis is parallel to the second longitudinal axis, and the first piston rod and the second piston rod are movable in opposite directions.
A combination of a concrete mixer truck having a concrete delivery chute for delivering concrete from the concrete mixer truck to a preselected location, and a hydraulic actuator assembly attached to the concrete mixer truck for positioning the concrete delivery chute relative to the concrete mixer truck, comprising:
- a first hydraulic actuator having a first cylinder with a first longitudinal axis, and a first piston slidable within the cylinder and attached to a first piston rod for movement along the first longitudinal axis with respect to the cylinder;
- a second hydraulic actuator having a second cylinder with a second longitudinal axis, a second piston slidable in the second cylinder and attached to a second piston rod for movement along the second longitudinal axis with respect to the second cylinder, and a non-rotation mounting between the second piston rod and the second cylinder for non-rotational movement of the second piston rod about the second longitudinal axis;
- and
- a rigid mounting between the first cylinder and the second cylinder so that the first longitudinal axis is parallel to the second longitudinal axis, and the first piston rod and the second piston rod are movable in opposite directions.
Dependencies are inferred from the claim text.