Foldable inclined multi-section ramp actuation system
AssigneeMcDonnell Douglas Corporation
InventorWilfred E. Boehringer
Life of this patent
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Abstract
A foldable, articulated inclined ramp or stair assembly actuation system is shown and described. The assembly comprises at least three elements connected by hinges to each other and foldable on each other under the control of a series of pulleys interconnected by a single drive cable. A method of operating the arrangement is described whereby an orderly folding sequence is automatically maintained by the actuating means. The assembly is suitable for installation within an aircraft and may be power driven to extend and retract through a loading door, thus obviating the need for any ground equipment for the purpose.
Claims32
Foldable, articulated ramp apparatus comprising in combination:
- at least three separate ramp sections foldable for storage within a vehicle and extendible therefrom, including first and second sections pivotably joined together by a first hinge mechanism for relative rotation about a first hinge axis;
- and a third section pivotably joined by a second hinge mechanism to the second section outboard of the first section for relative rotation about a second hinge axis;
- a plurality of pulleys individually mounted at respective hinge axes for rotation thereabout;
- cable anchoring means mounted on one of said sections;
- cable driving means mounted inboard of said cable anchoring means relative to the vehicle;
- and
- a cable extending about each of the pulleys and between the cable anchoring means and the cable driving means for folding and unfolding the ramp sections relative to each other.
Cable drive apparatus for driving a series of at least three ramp sections between extended, unfolded and retracted, folded positions wherein each section is hingedly connected in tandem to at least an adjacent section for relative rotation about a hinge axis and including:
- a plurality of pulleys individually mounted on respective ones of said hinge axes;
- a cable wound about said pulleys in succession for folding the ramp sections in a first rotational direction in sequence beginning with the outermost section and for unfolding the ramp sections in the reverse rotational direction;
- and
- means for controlling the movement of the cable.
An actuation system for driving between extended and retracted positions a multiple element apparatus of at least three elements pivotably interconnected by pairs at pivot axes between adjacent pairs of elements comprising:
- a plurality of pulleys individually mounted at respective pivot axes for rotation thereabout;
- cable anchoring means distinct from said pulleys mounted on one of said elements at one end of said apparatus;
- cable driving means mounted adjacent the other end of said apparatus;
- and
- a cable extending about each of the pulleys in succession and between the cable anchoring means and the cable driving means for folding and unfolding the elements relative to each other, the cable being wound about each pulley in a direction to fold the elements in the same rotational direction about their associated pivot axes during retraction of the apparatus.
Dependencies are inferred from the claim text.