Ambulator drive mechanism

• US 4,258,815 A
• Filed: 01/29/1979
• Issued: 03/31/1981
• Est. Priority Date: 01/29/1979
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Garrett, Robert A., Wier, John P.
• Primary Examiner(s): Silverstrim, John P.
• Application Number:
  US06/007,285
• Time in Patent Office: 792 Days
• Field of Search: 180/7 R, 180/7 A, 180/6.48, 180/6.5, 180/6.2, 301/5 P, 305/60
• US Class Current: 180/6.48
• CPC Class Codes: A61G 2200/36 standing
• CPC Class Codes: A61G 5/046 at least three driven wheels
• CPC Class Codes: A61G 5/1051 Arrangements for steering
• CPC Class Codes: A61G 5/12 Rests specially adapted therefor, e.g. for the head or the feet
• CPC Class Codes: B60B 19/003 Multidirectional wheels
• CPC Class Codes: B60B 2200/26 Medical appliances
• CPC Class Codes: B60B 2310/302 by welding
• CPC Class Codes: B60B 2310/305 by screwing
• CPC Class Codes: B60B 2360/32 Plastic compositions
• CPC Class Codes: B60B 2380/12 Ball bearings

Abstract

A drive mechanism is provided particularly suitable for use in ambulators ving a mobile platform that transports a paraplegic in a standing position, the unique drive mechanism enabling the platform to be of a minimum size with a very low center of gravity, and being movable about three axes to provide maximum maneuverability and access to confined spaces.

Claims

1. A maneuverable, self-propelled land vehicle comprising:

a rectangular chassis;

a plurality of identical wheels for supporting and moving said chassis, each wheel mounted at a respective corner of said chassis, and each wheel having a fixed axis of rotation, each axis inclined in such a manner that all of said axes intersect below said chassis at a point on its vertical centerline, whereby the vehicle is provided with a minimum center of gravity;

each wheel comprising a plurality of rollers mounted in spaced relation around its periphery, each roller having an axis of rotation lying in a common plane perpendicular to the axis of rotation of its respective wheel;

said plane containing the roller axes being slightly inclined with respect to a surface over which the vehicle is to be propelled so that only a limited number of the rollers on each wheel engage the surface at any given time during wheel rotation;

an independently reversible drive means for each wheel, wherein each wheel can be rotated in either a clockwise or counterclockwise direction;

whereby driving the wheels in a preselected pattern can propel the vehicle in any movement in at least two axes.

2. The vehicle of claim 1 wherein each of said rollers has a substantial thickness with respect to its diameter to provide maximum traction with the surface.

3. The vehicle of claim 1 wherein the periphery of the rollers of each wheel are located close to the outer edges of said chassis to provide the largest wheel base.