Article movement systems, ball wheels and related apparatus and methods

Abstract

An article movement system includes an article and at least one ball wheel. The article has first and second article surfaces meeting at a first article edge. The ball wheel is located along the first article edge and includes a ball, a bearing arrangement and a shell. The ball engages a surface underlying the article, the bearing arrangement supports the ball for omni-directional rotational movement, and the shell is located along the first article edge and contains the ball and the bearing arrangement. The shell defines a non-circular ball opening through which a portion of the ball extends to contact the underlying surface. The article, the bearing arrangement and the shell are configured such that the ball wheel is able to support the article for omni-directional rolling motion over the underlying surface with either of the first and article surfaces parallel thereto, and at any orientation therebetween.

What is claimed is: 
     
         1 . An article movement system comprising:
 an article having first and second article surfaces meeting at a first article edge;   a first ball wheel located along the first article edge, the first ball wheel including:
 a ball for engaging an underlying surface; 
 a bearing arrangement for supporting the ball for omni-directional rotational movement; 
 a shell located along the first article edge and containing the ball and the bearing arrangement, the shell defining a non-circular ball opening through which a portion of the ball extends so as to be able to contact the underlying surface; 
   wherein the article, the bearing arrangement and the shell are configured such that the ball wheel is able to support the article for omni-directional rolling motion over the underlying surface with the first article surface parallel thereto, the second article surface parallel thereto, and at any orientation therebetween.   
     
     
         2 . The article movement system of  claim 1 , wherein the non-circular ball opening has a major angular extent and a minor angular extent, the major angular extent being greater than the minor angular extent. 
     
     
         3 . The article movement system of  claim 2 , wherein the first article edge extends generally along an edge x-axis and the ball rotates about a ball x-axis when the article is rolled along the underlying surface in the direction of a z-axis, the major angular extent extending partially around the ball x-axis, the minor angular extent extending partially around a ball z-axis intersecting the ball x-axis. 
     
     
         4 . The article movement system of  claim 3 , wherein the major angular extent is greater than approximately 90 degrees relative to the ball x-axis and the minor angular extent is less than approximately 160 degrees relative to the ball z-axis. 
     
     
         5 . The article movement system of  claim 4 , wherein the major angular extent is between approximately 120 degrees to approximately 200 degrees and the minor angular extent is between approximately 60 degrees to approximately 135 degrees. 
     
     
         6 . The article movement system of  claim 1 , wherein a peripheral lip extends toward the ball around the non-circular ball opening. 
     
     
         7 . The article movement system of  claim 6 , where an outer portion of an inner face of the peripheral lip has a radius of curvature equal to a radius of curvature of the ball. 
     
     
         8 . The article movement system of  claim 6 , wherein a spacing between the ball and the inner face of the peripheral lip is greater at an inner edge of the peripheral lip than at an outer edge of the peripheral lip. 
     
     
         9 . The article movement system of  claim 6 , wherein the peripheral lip is magnetized. 
     
     
         10 . The article movement system of  claim 1 , wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell. 
     
     
         11 . The article movement system of  claim 10 , wherein each of the plurality of micro-casters includes:
 an outer housing mounted to the shell;   an inner housing rotatably mounted within the outer housing; and   a caster wheel rotatably mounted in the inner housing such that a rotational axis of the caster wheel extends at a right angle to, but does not intersect, a rotational axis of the inner housing.   
     
     
         12 . The article movement system of  claim 11 , wherein each of the plurality of micro-casters further includes a plurality of ball bearings rotatably supporting the inner housing relative to the outer housing. 
     
     
         13 . The article movement system of  claim 11 , wherein each of the plurality of micro-casters further includes a cap fixed to and rotatable with the inner housing, the cap defining a caster wheel opening through which a portion the caster wheel extends. 
     
     
         14 . The article movement system of  claim 13 , further comprising a sealing ring surrounding the cap and enclosing a space between the inner and outer housings;
 wherein the cap and the sealing ring are contoured to continue a curvature of an inner surface of the shell adjacent thereto, except for a central protrusion of the cap extending around the caster wheel opening.   
     
     
         15 . The article movement system of  claim 10 , wherein the plurality of micro-casters includes four micro-casters, each of the four micro-casters positioned to engage a respective one of four quadrants of the ball. 
     
     
         16 . The article movement system of  claim 15 , wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 
     
     
         17 . The article movement system of  claim 15 , wherein the four micro-casters are positioned for dual engagement. 
     
     
         18 . The article movement system of  claim 10 , wherein the bearing arrangement further includes a plurality of ball bearings arranged in a bearing volume between the ball and the shell, the plurality of ball bearings being free to circulate therethrough around and over the micro-casters. 
     
     
         19 . The article movement system of  claim 1 , wherein the bearing arrangement includes a plurality of ball bearings arranged in a bearing volume between the ball and the shell, the plurality of ball bearings being free to circulate therethrough. 
     
     
         20 . The article movement system of  claim 19 , wherein the bearing arrangement further includes a bearing well defined in the shell and communicating with the bearing volume such that a portion of the plurality of ball bearings can freely circulate into and out of the bearing well. 
     
     
         21 . The article movement system of  claim 1 , wherein the first and second article surfaces are generally perpendicular, such that the article, the bearing arrangement and the shell are configured such that the first ball wheel is able to support the article for omni-directional rolling motion over the underlying surface in a horizontal orientation with the first article surface parallel to, in a vertical orientation with the second article surface parallel thereto, at any inclined orientation therebetween. 
     
     
         22 . The article movement system of  claim 21 , wherein the first ball wheel further includes a tracker wheel rotatably mounted in the shell such that, with the article in the vertical orientation, the tracker wheel is located horizontally adjacent to the ball and does not constrain omni-directional rotational movement thereof, and with the article in the inclined and horizontal orientations, the tracker wheel is located vertically above a portion of the ball and engagement of the ball with the tracker wheel results in enhanced rotational tracking of the ball in a direction perpendicular to a rotational axis of the tracker wheel. 
     
     
         23 . The article movement system of  claim 1 , wherein the shell includes an upwardly extending neck connected to the article. 
     
     
         24 . The article movement system of  claim 23 , wherein the first ball wheel further includes a suspension unit arranged around the neck and configured to absorb shocks experienced by the ball as it passes over the underlying surface. 
     
     
         25 . The article movement system of  claim 24 , wherein the suspension unit is removable from the neck as a single unit. 
     
     
         26 . The article movement system of  claim 23 , wherein an internal passage is defined extending through the neck and the first ball wheel further includes a brake unit arranged in the internal passage and operable to exert a braking force on the ball. 
     
     
         27 . The article movement system of  claim 26 , wherein the brake unit is removable from the neck as a single unit. 
     
     
         28 . The article movement system of  claim 26 , wherein the brake unit includes a brake shoe extendable towards the ball and operable to urge the ball into contact with a peripheral lip surrounding the non-circular ball opening. 
     
     
         29 . The article movement system of  claim 1 , further comprising a second ball wheel located along the first article edge and substantially identical to the first ball wheel. 
     
     
         30 . The article movement system of  claim 29 , further comprising third and fourth ball wheels located along a second article edge, the second article surface meeting a third article surface at the second article edge, the third and fourth ball wheels being substantially identical to the first and second ball wheels, and the first and third article surfaces forming opposite sides of the article.