A drive assembly can comprise a plurality of drive arms that are configured to receive a tangential drive force and convert the tangential drive force to a torque about a first axis. A driven rotatable element can be rotatable about a second axis that is parallel to the first axis. A coupling subassembly can couple the plurality of drive arms to the driven rotatable element so that the first axis is movable with respect to the second axis in first and second dimensions that are perpendicular to each other and the first and second axes. The coupling subassembly can be configured to bias the driven rotatable element toward a position in which the first axis is collinear with the second axis.

A conveyance to carry humans, such as a wheelchair, is described having levers on each side of the wheelchair that are manually moved forward and backward to propel the conveyance. The user is able to shift into forward, reverse or neutral, brake, and change mechanical advantage (gear ratio), all this without removing the user's hands from the drive levers.

A conveyance to carry humans, such as a wheelchair, is described having levers on each side of the wheelchair that are manually moved forward and backward to propel the conveyance. The user is able to shift into forward, reverse or neutral, brake, and change mechanical advantage (gear ratio), all this without removing the user's hands from the drive levers.

A device including a frame; an actuator attached to the frame and slidaby movable with respect to the frame along a linear axis, and a helical member positioned within the frame and rotatably movable with respect to the frame about a helical axis of the helical member, wherein the helical axis is parallel to the linear axis, wherein the actuator and the helical member are configured to cooperate with one another such that (a) motion of the actuator along the linear axis in a first linear direction causes corresponding rotation of the helical member about the helical axis in a first rotational direction and (b) motion of the actuator along the linear axis in a second linear direction that is opposite the first linear direction causes corresponding rotation of the helical member about the helical axis in a second rotational direction that is opposite the first rotational direction.

Disclosed is a multifunctional exercise chair for body stretching, comprising a wheelchair frame body, wherein a mounting frame is detachably mounted on an end of the wheelchair frame body away from the driving rear wheel and located under the seat cushion, a pedal gear is rotatably mounted at a bottom of the mounting frame and a pedal is provided thereon, a hand crank gear is rotatably mounted on a top of the mounting frame and a hand crank handle is provided thereon, a rotating shaft is provided between two driving rear wheels; a driven gear is fixedly mounted on the rotating shaft, a supporting chain gear is mounted on the mounting frame and arranged adjacent to the pedal gear, and the hand crank gear, the pedal gear, the driven gear and the supporting chain gear are wound and connected by a transmission chain.

A hand propelled wheeled vehicle, specifically a wheelchair, containing a pair of hand actuated, lever driven mechanisms to rotate the main wheels. The levers pivot around attachment points on the left and right sides of the vehicle chassis. The left lever actuates a frame responsible for contra-rotating two integral one-way clutches arranged on a drive shaft coupled to the left main wheel, with the right lever operating the right side mechanism in an identical fashion. The arrangements of the clutches utilize both the forward (pushing) and backward (pulling) stroke of the lever to rotate the main wheels forward. Steering and braking control is afforded through attachments integral to the hand grips of the right and left hand levers, respectively.

A mobile chair apparatus is described that comprises a drive assembly that preferably includes one or more moveable foot pedals, and drive wheels which rotate in response to rotation of the foot pedals by the mobile chair occupant, and a steering assembly which comprises two steering wheels and two armrests, wherein movement of just one armrest will translate into movement of both steering wheels, and wherein the drive assembly and the steering assembly concurrently enable the mobile chair occupant to propel and steer the mobile chair apparatus without assistance from another person.

An apparatus comprising a steering assembly, a drive assembly and a seat, the steering assembly comprises a first armrest connected to a first link arm, and a second armrest connected to a second link arm; a first tie rod connected to the first link arm and a second tie rod connected to the second link arm; a first steering block connected to the first tie rod and a second steering block connected to the second tie rod; a third tie rod interconnecting the first and second steering blocks; and a first and second steering wheel, and/or the drive assembly comprises a first and second drive wheel connected to an axle; a support shaft; foot pedals connected to a crank; a first chain connecting the crank to a gear hub; and a second chain connecting the gear hub to the axles or connecting components of the gear hub.

A transmission apparatus for a leveraged wheelchair may include a wheelchair, a driving mechanism, a driving wheels set, and a transmission wheels set. The driving mechanism has a first tube and a second tube which are pivotally connected, and with the relative movements between the first tube and the second tube, the driving wheels set can have forward or rearward rotation so as to achieve bi-direction driving effect of the wheelchair. Also, the relative movement between the first tube and the second tube is cooperated with a flexible connecting head such that a handle of the wheelchair is adapted to be forward and rearward pulled or rotated axially so to achieve the moving and turning actions of the wheelchair with one hand.

A rack driven human powered vehicle utilizes a rack and pinion system to provide a more efficient method of propulsion. The rack and pinion system may take the linear momentum of at least one driving rack and may transfer it to rotational momentum for at least one freewheel sprocket which may turn the wheel providing momentum for the vehicle.