Abstract: A method of operating a wheelchair during an un-recline process involves a wheelchair having tilt and recline functions, the wheelchair including a seat frame, a tilt actuator for tilting the seat frame, a back frame, a recline actuator for reclining the back frame. A sensor for determining the angle of recline is provided. A controller for controlling the tilt actuator and recline actuator is also provided. The controller is provided with a plurality of preprogrammed sequences for moving the seat frame and the back frame during an unrecline procedure. The sequences include tilting the seat frame as an initial part of the unrecline sequence, wherein the sequences are a function of the initial angle of recline at the initiation of the recline sequence. An initial angle of recline at the initiation of a recline sequence is determined, and the back frame is unreclined according to one of the preprogrammed sequences in response to the determined initial angle of recline.

Abstract: A wheelchair has a seat frame and a back frame, the wheelchair being configured to tilt the seat frame from an initial position to a tilted position. The wheelchair includes a rear anti-tip wheel pivotally mounted for vertical articulation within a first range of motion. A means for limiting the vertical articulation to a second narrower range of motion in response to tilting of the seat frame is provided.

Abstract: A method of operating a wheelchair during an un-recline process, where the wheelchair includes a seat frame and a back frame, includes positioning the wheelchair user in the wheelchair with the back frame reclined, and rotating the seat frame of the wheelchair so that the seat frame and the back frame form an angle that is within the range of from about 80 degrees to about 120 degrees. The back frame is unreclined by rotating the back frame and the seat frame while maintaining the angle between the seat frame and the back frame within the range of from about 80 degrees to about 120 degrees.

Abstract: A method of operating a wheelchair during an un-recline process involves a wheelchair having tilt and recline functions, the wheelchair including a seat frame, a tilt actuator for tilting the seat frame, a back frame, a recline actuator for reclining the back frame. A sensor for determining the angle of recline is provided. A controller for controlling the tilt actuator and recline actuator is also provided. The controller is provided with a plurality of preprogrammed sequences for moving the seat frame and the back frame during an unrecline procedure. The sequences include tilting the seat frame as an initial part of the unrecline sequence, wherein the sequences are a function of the initial angle of recline at the initiation of the recline sequence. An initial angle of recline at the initiation of a recline sequence is determined, and the back frame is unreclined according to one of the preprogrammed sequences in response to the determined initial angle of recline.

Abstract: A wheelchair has a seat frame, legrests pivotally mounted for elevation with respect to the seat frame, and an elevation mechanism. The elevation mechanism includes a latch link having a legrest end attached to the legrest, and a pivot end. Also included is a pivot link having a frame end pivotally connected to the seat frame, and having a latch link end pivotally connected to the pivot end of the latch link., The latch link end of the pivot link and the pivot end of the latch link are pivotally connected through a latch pin. An actuator having a piston movable in forward and rearward directions with respect to the seat frame is provided to pivot the legrests relative to the seat frame, the piston having a forward end that is connected to one of the latch pin, the latch link, and the pivot link.

Abstract: A wheelchair has a base and further comprises a seat frame mounted for tilting with respect to the base, and a seat frame tilting mechanism for rotating the seat frame with respect to the base. A back frame is mounted for reclining with respect to the base, and a back frame recline mechanism is positioned for rotating the back frame with respect to the base. A controller is provided for separately controlling the seat frame tilting mechanism and back frame recline mechanism so that the seat frame and the back frame can be rotated independently.

Abstract: A tilt system for tilting a power wheelchair seat comprises a seat frame having laterally extending front and rear cross tubes and side tubes. A rear cross plate extends laterally between the wheelchair side frames and is slidably engageable with the side frames. A pivotal connection is provided between the rear seat cross tube and the rear cross plate. A front actuator cross tube is supported at a front end of the wheelchair base. A linear actuator is supported between the rear cross plate and the front actuator cross tube. A tilt linkage is disposed along opposite sides of the seat frame. Each tilt linkage has a front end pivotally connected to the wheelchair base and a rear end pivotally connected one of the side tubes of the seat frame. Another embodiment of the invention includes a glide system is secured to the inner surfaces of the wheelchair side frames. Another embodiment of the invention includes a wheelchair having a base comprises of two side frames.

Abstract: A wheelchair seat has a backrest assembly with a counter balance to provide equilibrium. A control loop is included on the sliding backrest to sense the onset of shear and compensate the backrest to a zero shear position during recline. A legrest assembly has a selectable lift arrangement for either independent or recline lift.