Support leg system and method for supporting a dock leveler
AssigneeSPX Dock Products, Inc.
InventorsRichard K. Hoofard, James C. Alexander, Douglas H. Massey
Life of this patent
Estimating the term…
Abstract
A dock leveler includes a support leg system configured to remain in a support position when the dock leveler descends rapidly and retract when the dock leveler descends slowly. A disengaging system is also included to disengage the support legs from retracting when the dock level lip is in a pendant position. A method of operating a dock leveler includes keeping a support leg in a support position when a dock leveler descends rapidly and retracting a support leg when the dock leveler descends slowly.
Claims22
A dock leveler having a ramp configured to move between a raised and one or more lowered positions, comprising:
- a support leg means for supporting the ramp, the support leg means configured to move between a support position, through intermediate positions, to a retracted position;
- means for biasing the support leg means to the support position;
- and,
- means for urging the support leg means to move from the support position to the retracted position when the ramp moves slower than a predetermined rate toward the one or more lowered positions, and for maintaining the support leg means in the support position or an intermediate position when the ramp moves at or greater than the predetermined rate toward the one or more lowered positions, wherein the means for urging comprises a cam arm, a cam, a spring, and a cam engaging surface, wherein
- the cam arm has a first end and a second end and is connected to the cam at the first end and the spring at the second end,
- the cam has a retracted and non-retracted position and the spring and support leg means act cooperatively to bias the cam arm toward its non-retracted position, and
- the cam engaging surface urges the cam arm to move into the retracted position when the ramp moves toward the one or more lowered positions at or greater than the predetermined rate and provides a pathway for the cam to move along when the ramp moves toward the one or more lowered positions slower than the predetermined rate.
A method of alleviating free-fall of a dock-leveler ramp when a truck suddenly disengages from a dock-leveler ramp, comprising providing a dock leveler having a support leg system for supporting the ramp and a cam assembly for moving the support leg between a support position and a retracted position,
- wherein the support leg is biased to the support position and moves to the retracted position when the ramp moves slower than a predetermined rate toward a lowered position, and
- wherein the cam assembly comprises a cam arm having a first and second end, a cam connected to the first end of the cam arm, a spring operatively connected to the second end of the cam arm and the support leg to bias the cam arm to a non-retracted position, and a cam engaging surface which urges the cam arm to move into the retracted position when the ramp moves toward the lowered position at or greater than the predetermined rate and provides a pathway for the cam to move along when the ramp moves toward the lowered position slower than the predetermined rate.
Dependencies are inferred from the claim text.