Wheelchair lift

A lift mountable in a vehicle adjacent an access opening thereof, for use in moving an object such as a wheelchair to and from a generally horizontal bed of the vehicle, comprising:

• a pair of parallelogram linkages each having a base link mountable in the vehicle adjacent the access opening, two side-by-side elongated arms pivotally mounted on said base link for swinging about spaced, parallel axes between upright positions in the vehicle and outwardly extending, lowered positions, and an end link pivotally mounted on the ends of said arms opposite said base link;
• said linkages being spaced apart for mounting in the vehicle for swinging in substantially parallel planes;
• a platform for holding the object;
• means connecting one edge portion of said platform to both of said end links and holding the platform in a preselected angular position on said end links to maintain the platform generally parallel to said bed during swinging of said linkages and to move said one edge along an arc passing close to the end of the bed at the access opening;
• and drive means for selectively swinging said linkages to said upright position, said lowered position, and an intermediate position in which said platform is level with the bed with said one edge adjacent the end thereof, including a reversible electric motor and operating circuitry therefor, first and second manual actuating switches for operating said motor from outside the vehicle and from inside the vehicle, a third manual switch mounted adjacent said platform for movement therewith and for operation by a person on the platform, and switch means responsive to movement of said platform to said intermediate position from either direction for overriding said third switch and stopping the platform in said intermediate position.

A lift mountable in a vehicle adjacent an access opening thereof, for use in moving an object such as a wheelchair to and from a generally horizontal bed of the vehicle, comprising:

• a pair of parallelogram linkages each having a base link mountable in the vehicle adjacent the access opening, two side-by-side elongated arms pivotally mounted on said base link for swinging about spaced, parallel axes between upright positions in the vehicle and outwardly extending, lowered positions, and an end link pivotally mounted on the ends of said arms opposite said base link;
• said linkages being spaced apart for mounting in the vehicle for swinging in substantially parallel planes;
• a platform for holding the object;
• two posts extending from said end links down to said platform;
• a pivot connecting the lower end portion of each post to said platform adjacent a front corner thereof, for tilting of the platform about an axis disposed above, and extending along, a front edge of the platform, and holding said platform for movement of said front edge along an arc passing close to the end of the bed at the access opening, and beyond the end of the bed, into the vehicle;
• means for preventing downward tilting of said platform from a generally horizontal position, but permitting upward tilting into a storage position in which the rear edge of the platform is adjacent said posts;
• drive means for selectively swinging the linkages, in unison, to said upright position, said lowered position, and an intermediate position in which said platform is level with the bed with said front edge adjacent, but spaced from, the end thereof;
• means on said platform and said linkages for tilting said platform to said storage position automatically as an incident to movement of said linkages to said upright positions, comprising at least one set of cam and follower elements including a follower on said platform adjacent said front edge, and a cam on one of said base links inside the vehicle positioned to engage said follower and cam the latter downwardly as said linkages move into said upright positions.

A lift mountable in a vehicle adjacent an access opening thereof, for use in moving an object such as a wheelchair to and from a generally horizontal bed of the vehicle, comprising:

• a pair of parallelogram linkages each having a base link mountable in the vehicle adjacent the access opening, two side-by-side elongated arms pivotally mounted on said base link for swinging about spaced, parallel axes between upright positions in the vehicle and outwardly extending, lowered positions, and an end link pivotally mounted on the ends of said arms opposite said base link;
• said linkages being spaced apart for mounting in the vehicle for swinging in substantially parallel planes;
• a platform for holding the object;
• two posts extending from said end links down to said platform;
• a pivot connecting the lower end portion of each post to said platform adjacent a front corner thereof, for tilting of the platform about an axis disposed above, and extending along, a front edge of the platform, and holding said platform for movement of said front edge along an arc passing close to the end of the bed at the access opening, and beyond the end of the bed, into the vehicle;
• means for preventing downward tilting of said platform from a generally horizontal position, but permitting upward tilting into a storage position in which the rear edge of the platform is adjacent said posts;
• drive means for selectively swinging the linkages, in unison, to said upright position, said lowered positions;
• and an intermediate position in which said platform is level with the bed with said front edge adjacent, but spaced from, the end thereof, said drive means including two sprockets rotatably supported in the vehicle adjacent said access opening above the bed thereof, a chain for each of said sprockets having one end portion extending from the sprocket outwardly over one of the linkages, means connecting said chains to said linkages, means for driving said sprockets to feed said chains back and forth and swing said linkages between said positions;
• means for tilting said platform to said storage position automatically as said linkages move to said upright positions and including means stopping inward movement of said platform as said linkages move to said upright positions, and means, including said chains, operating to tilt the platform to said storage position after inward movement of said platform is stopped.

In a wheelchair lift device mounted in an opening of a vehicle for selectively moving a wheelchair to the bed of the vehicle from the ground adjacent the vehicle and to the ground from the bed of the vehicle, the combination comprising

• two base structures rigidly mounted to the vehicle, one of each of said structures located adjacent opposite sides of the opening of the vehicle so as to not interfere with entry or egress through said opening,
• two straight members, each pivotally mounted at one of its ends to spaced points on each of said base structures for arcuate parallel movement about the pivotal mounts between an upright position in the vehicle to an outwardly extending lowered position,
• two straight end link members, each pivotally attached to the ends of one pair of said straight members at their ends opposite said base structures,
• a movable horizontally arranged platform for receiving the wheelchair and occupant,
• means connecting one edge portion of said platform to both of said end link members and for holding the platform in a substantially horizontal plane during the arcuate parallel movement of the two pairs of straight members,
• drive means comprising a reversible electrical motor for selectively moving said straight members through said arcuate parallel movement,
• means for selectively causing said platform to rotate about one edge to a tilted, stored position within said vehicle when said pairs of straight members are in their upright position in the vehicle, and,
• electrical switches selectively operable to determine the extent and direction of movement of said straight members and said platform and the
• direction of rotation of said motor.

A lift mountable in a vehicle adjacent an access opening thereof, for use in moving an object such as a wheelchair to and from a generally horizontal bed of the vehicle, comprising:

• a pair of parallelogram linkages each having a base link mountable in the vehicle adjacent the access opening, two elongated arms pivotally mounted on said base link for swinging about spaced, parallel axes between upright positions in the vehicle and outwardly extending, lowered positions, and an end link pivotally mounted on the ends of said arms opposite said base link;
• said linkages being spaced apart for mounting in the vehicle for swinging in substantially parallel planes;
• a platform for holding the object;
• means pivotally connecting one edge portion of said platform to both of said end links for moving said one edge along an arc passing close to the end of the bed at the access opening;
• drive means for selectively swinging the arms of said linkages from said lowered positions to said upright positions and back and further coupled for tilting the platform into a vertical storage position about an axis generally along the one edge of the platform after the elongated arms of said linkages have reached the upright position;
• control means for actuating said drive means and for stopping said linkages in each direction of movement with said platform in an intermediate position level with the bed, for movement of a wheelchair into and out of the vehicle;
• and
• means for preventing downward tilting of said platform from a preselected angular position, but permitting upward tilting into the storage position.