Helical drive mechanism and handle mechanism for wheelchair with helical drive

Abstract

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.

What is claimed is: 
     
         1 . A device, comprising:
 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.   
     
     
         2 . The device of  claim 1 , wherein the at least one follower bearing includes a first follower bearing positioned to a first side of the helical member and a second follower bearing positioned to a second side of the helical member that is opposite the first side of the helical member. 
     
     
         3 . The device of  claim 1 , further comprising at least one plain bearing positioned on a portion of the frame so as to reduce friction between the helical member and the frame when the helical member rotates about the helical axis. 
     
     
         4 . The device of  claim 1 , wherein the helical member has a helical pitch of between 85 millimeters and 95 millimeters. 
     
     
         5 . The device of  claim 1 , wherein the helical member has a lead angle of between 24 degrees and 27 degrees. 
     
     
         6 . The device of  claim 1 , wherein the helical member has a pitch diameter of between 48 millimeters and 52 millimeters. 
     
     
         7 . A system, comprising:
 a frame;   an actuator attached to the frame and slidaby movable with respect to the frame along a linear axis,   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; and   a drive shaft coupled to the helical member, wherein the drive shaft has a longitudinal 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, and   wherein the drive shaft is coupled to the helical member in a manner such that (a) rotation of the helical member about the helical axis in the first rotational direction causes corresponding rotation of the drive shaft about the longitudinal axis in a first rotational direction and (b) rotation of the helical member about the helical axis in the second rotational direction causes corresponding rotation of the drive shaft about the longitudinal axis in a second rotational direction that is opposite the first rotational direction of the longitudinal axis.   
     
     
         8 . The system of  claim 7 , wherein the helical member has a helical pitch of between 85 millimeters and 95 millimeters. 
     
     
         9 . The system of  claim 7 , wherein the helical member has a lead angle of between 24 degrees and 27 degrees. 
     
     
         10 . The system of  claim 7 , wherein the helical member has a pitch diameter of between 48 millimeters and 52 millimeters. 
     
     
         11 . The system of  claim 7 , wherein the drive shaft is coupled to drive system of a vehicle in a manner so as to propel the vehicle. 
     
     
         12 . The system of  claim 11 , wherein the vehicle is a wheelchair.