초록 ▼

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 und

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.

대표청구항 ▼

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 ba

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 of the article therebetween;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; andwherein 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. 2. The article movement system of claim 1, 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. 3. The article movement system of claim 2, 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. 4. The article movement system of claim 1, wherein a peripheral lip extends toward the ball around the non-circular ball opening. 5. The article movement system of claim 4, 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. 6. The article movement system of claim 4, 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. 7. The article movement system of claim 4, wherein the peripheral lip is magnetized. 8. The article movement system of claim 1, wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell. 9. The article movement system of claim 8, 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; anda 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. 10. The article movement system of claim 9, 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. 11. The article movement system of claim 9, 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 of the caster wheel extends. 12. The article movement system of claim 11, 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. 13. The article movement system of claim 8, 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. 14. The article movement system of claim 13, wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 15. The article movement system of claim 13, wherein the four micro-casters are positioned for dual engagement. 16. The article movement system of claim 8, 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. 17. 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. 18. The article movement system of claim 17, 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. 19. 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. 20. The article movement system of claim 19, 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. 21. The article movement system of claim 1, wherein the shell includes an upwardly extending neck connected to the article. 22. The article movement system of claim 21, 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. 23. The article movement system of claim 22, wherein the suspension unit is removable from the neck as a single unit. 24. The article movement system of claim 21, 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. 25. The article movement system of claim 24, wherein the brake unit is removable from the neck as a single unit. 26. The article movement system of claim 24, 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. 27. 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. 28. The article movement system of claim 27, 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. 29. 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 of the article therebetween;wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell; andwherein each of the plurality of micro-casters includes: a first portion mounted to the shell;a second portion rotatably mounted to the first portion; anda caster wheel rotatably mounted to the second portion such that a rotational axis of the caster wheel extends at a right angle to, but does not intersect, a rotational axis of the second portion. 30. The article movement system of claim 29, wherein, in each of the plurality of micro-casters, the first portion is an outer housing and the second portion is an inner housing rotatably mounted within the outer housing, the caster wheel being rotatably mounted in the inner housing. 31. The article movement system of claim 30, 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. 32. The article movement system of claim 30, 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 of the caster wheel extends. 33. The article movement system of claim 32, 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. 34. The article movement system of claim 29, 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. 35. The article movement system of claim 34, 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. 36. The article movement system of claim 35, 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. 37. The article movement system of claim 36, 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. 38. The article movement system of claim 29, wherein a peripheral lip extends toward the ball around the non-circular ball opening. 39. The article movement system of claim 38, 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. 40. The article movement system of claim 38, 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. 41. The article movement system of claim 38, wherein the peripheral lip is magnetized. 42. The article movement system of claim 29, 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. 43. The article movement system of claim 42, wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 44. The article movement system of claim 42, wherein the four micro-casters are positioned for dual engagement. 45. The article movement system of claim 29, 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. 46. The article movement system of claim 29, 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. 47. The article movement system of claim 46, 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. 48. The article movement system of claim 29, 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. 49. The article movement system of claim 48, 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. 50. The article movement system of claim 29, wherein the shell includes an upwardly extending neck connected to the article. 51. The article movement system of claim 50, 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. 52. The article movement system of claim 51, wherein the suspension unit is removable from the neck as a single unit. 53. The article movement system of claim 50, 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. 54. The article movement system of claim 53, wherein the brake unit is removable from the neck as a single unit. 55. The article movement system of claim 53, 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. 56. The article movement system of claim 29, further comprising a second ball wheel located along the first article edge and substantially identical to the first ball wheel. 57. The article movement system of claim 56, 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. 58. 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 of the article therebetween;wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell; andwherein 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. 59. The article movement system of claim 58, 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. 60. The article movement system of claim 59, 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. 61. The article movement system of claim 60, 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. 62. The article movement system of claim 61, 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. 63. The article movement system of claim 58, wherein a peripheral lip extends toward the ball around the non-circular ball opening. 64. The article movement system of claim 63, 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. 65. The article movement system of claim 63, 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. 66. The article movement system of claim 63, wherein the peripheral lip is magnetized. 67. The article movement system of claim 58, 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; anda 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. 68. The article movement system of claim 67, 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. 69. The article movement system of claim 67, 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 of the caster wheel extends. 70. The article movement system of claim 69, 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. 71. The article movement system of claim 58, wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 72. The article movement system of claim 58, wherein the four micro-casters are positioned for dual engagement. 73. The article movement system of claim 58, 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. 74. The article movement system of claim 58, 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. 75. The article movement system of claim 74, 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. 76. The article movement system of claim 58, 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. 77. The article movement system of claim 76, 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. 78. The article movement system of claim 58, wherein the shell includes an upwardly extending neck connected to the article. 79. The article movement system of claim 78, 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. 80. The article movement system of claim 79, wherein the suspension unit is removable from the neck as a single unit. 81. The article movement system of claim 78, 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. 82. The article movement system of claim 81, wherein the brake unit is removable from the neck as a single unit. 83. The article movement system of claim 81, 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. 84. The article movement system of claim 58, further comprising a second ball wheel located along the first article edge and substantially identical to the first ball wheel. 85. The article movement system of claim 84, 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. 86. 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 of the article therebetween; andwherein 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. 87. The article movement system of claim 86, 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. 88. The article movement system of claim 87, 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. 89. The article movement system of claim 88, 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. 90. The article movement system of claim 89, 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. 91. The article movement system of claim 86, wherein a peripheral lip extends toward the ball around the non-circular ball opening. 92. The article movement system of claim 91, 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. 93. The article movement system of claim 91, 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. 94. The article movement system of claim 91, wherein the peripheral lip is magnetized. 95. The article movement system of claim 86, wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell. 96. The article movement system of claim 95, 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; anda 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. 97. The article movement system of claim 96, 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. 98. The article movement system of claim 96, 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 of the caster wheel extends. 99. The article movement system of claim 98, 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. 100. The article movement system of claim 95, 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. 101. The article movement system of claim 100, wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 102. The article movement system of claim 100, wherein the four micro-casters are positioned for dual engagement. 103. The article movement system of claim 95, wherein the plurality of ball bearings are free to circulate therethrough around and over the micro-casters. 104. The article movement system of claim 86, 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. 105. The article movement system of claim 86, 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. 106. The article movement system of claim 105, 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. 107. The article movement system of claim 86, wherein the shell includes an upwardly extending neck connected to the article. 108. The article movement system of claim 107, 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. 109. The article movement system of claim 108, wherein the suspension unit is removable from the neck as a single unit. 110. The article movement system of claim 107, 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. 111. The article movement system of claim 110, wherein the brake unit is removable from the neck as a single unit. 112. The article movement system of claim 110, 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. 113. The article movement system of claim 86, further comprising a second ball wheel located along the first article edge and substantially identical to the first ball wheel. 114. The article movement system of claim 113, 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. 115. 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 of the article therebetween; andwherein 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. 116. The article movement system of claim 115, 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. 117. The article movement system of claim 116, 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. 118. The article movement system of claim 117, 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. 119. The article movement system of claim 118, 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. 120. The article movement system of claim 115, wherein a peripheral lip extends toward the ball around the non-circular ball opening. 121. The article movement system of claim 120, 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. 122. The article movement system of claim 120, 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. 123. The article movement system of claim 120, wherein the peripheral lip is magnetized. 124. The article movement system of claim 115, wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell. 125. The article movement system of claim 124, 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; anda 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. 126. The article movement system of claim 125, 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. 127. The article movement system of claim 125, 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 of the caster wheel extends. 128. The article movement system of claim 127, 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. 129. The article movement system of claim 124, 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. 130. The article movement system of claim 129, wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 131. The article movement system of claim 129, wherein the four micro-casters are positioned for dual engagement. 132. The article movement system of claim 124, 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. 133. The article movement system of claim 115, 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. 134. The article movement system of claim 133, 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. 135. The article movement system of claim 115, 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. 136. The article movement system of claim 115, wherein the shell includes an upwardly extending neck connected to the article. 137. The article movement system of claim 136, 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. 138. The article movement system of claim 137, wherein the suspension unit is removable from the neck as a single unit. 139. The article movement system of claim 136, 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. 140. The article movement system of claim 139, wherein the brake unit is removable from the neck as a single unit. 141. The article movement system of claim 139, 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. 142. The article movement system of claim 115, further comprising a second ball wheel located along the first article edge and substantially identical to the first ball wheel. 143. The article movement system of claim 142, 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. 144. 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 of the article therebetween;wherein the shell includes an upwardly extending neck connected to the article; andwherein 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. 145. The article movement system of claim 144, 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. 146. The article movement system of claim 145, 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. 147. The article movement system of claim 146, 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. 148. The article movement system of claim 147, 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. 149. The article movement system of claim 144, wherein a peripheral lip extends toward the ball around the non-circular ball opening. 150. The article movement system of claim 149, 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. 151. The article movement system of claim 149, 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. 152. The article movement system of claim 149, wherein the peripheral lip is magnetized. 153. The article movement system of claim 144 wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell. 154. The article movement system of claim 153, 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; anda 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. 155. The article movement system of claim 154, 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. 156. The article movement system of claim 154, 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 of the caster wheel extends. 157. The article movement system of claim 156, 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. 158. The article movement system of claim 153, 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. 159. The article movement system of claim 158, wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 160. The article movement system of claim 158, wherein the four micro-casters are positioned for dual engagement. 161. The article movement system of claim 153, 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. 162. The article movement system of claim 144, 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. 163. The article movement system of claim 162, 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. 164. The article movement system of claim 144, 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. 165. The article movement system of claim 164, 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. 166. The article movement system of claim 144, wherein the suspension unit is removable from the neck as a single unit. 167. The article movement system of claim 144, 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. 168. The article movement system of claim 167, wherein the brake unit is removable from the neck as a single unit. 169. The article movement system of claim 167, 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. 170. The article movement system of claim 144, further comprising a second ball wheel located along the first article edge and substantially identical to the first ball wheel. 171. The article movement system of claim 170, 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. 172. 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 of the article therebetween;wherein the shell includes an upwardly extending neck connected to the article; andwherein 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. 173. The article movement system of claim 172, 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. 174. The article movement system of claim 173, 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. 175. The article movement system of claim 174, 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. 176. The article movement system of claim 175, 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. 177. The article movement system of claim 172, wherein a peripheral lip extends toward the ball around the non-circular ball opening. 178. The article movement system of claim 177, 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. 179. The article movement system of claim 177, 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. 180. The article movement system of claim 177, wherein the peripheral lip is magnetized. 181. The article movement system of claim 172, wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell. 182. The article movement system of claim 181, 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; anda 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. 183. The article movement system of claim 182, 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. 184. The article movement system of claim 182, 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 of the caster wheel extends. 185. The article movement system of claim 184, 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. 186. The article movement system of claim 181, 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. 187. The article movement system of claim 186, wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 188. The article movement system of claim 186, wherein the four micro-casters are positioned for dual engagement. 189. The article movement system of claim 181, 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. 190. The article movement system of claim 172, 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. 191. The article movement system of claim 190, 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. 192. The article movement system of claim 172, 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. 193. The article movement system of claim 192, 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. 194. The article movement system of claim 172, 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. 195. The article movement system of claim 194, wherein the suspension unit is removable from the neck as a single unit. 196. The article movement system of claim 172, wherein the brake unit is removable from the neck as a single unit. 197. The article movement system of claim 172, 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. 198. The article movement system of claim 172, further comprising a second ball wheel located along the first article edge and substantially identical to the first ball wheel. 199. The article movement system of claim 198, 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. 200. 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 of the article therebetween;further comprising a second ball wheel located along the first article edge and substantially identical to the first ball wheel; andfurther 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. 201. The article movement system of claim 200, 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. 202. The article movement system of claim 201, 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. 203. The article movement system of claim 202, 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. 204. The article movement system of claim 203, 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. 205. The article movement system of claim 200, wherein a peripheral lip extends toward the ball around the non-circular ball opening. 206. The article movement system of claim 205, 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. 207. The article movement system of claim 205, 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. 208. The article movement system of claim 205, wherein the peripheral lip is magnetized. 209. The article movement system of claim 200, wherein the bearing arrangement includes a plurality of micro-casters engaging the ball from within the shell. 210. The article movement system of claim 209, 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; anda 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. 211. The article movement system of claim 210, 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. 212. The article movement system of claim 210, 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 of the caster wheel extends. 213. The article movement system of claim 212, 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. 214. The article movement system of claim 209, 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. 215. The article movement system of claim 214, wherein the non-circular ball opening has a major angular extent and a minor angular extent, the four quadrants being formed therebetween. 216. The article movement system of claim 214, wherein the four micro-casters are positioned for dual engagement. 217. The article movement system of claim 209, 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. 218. The article movement system of claim 200, 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. 219. The article movement system of claim 218, 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. 220. The article movement system of claim 200, 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. 221. The article movement system of claim 220, 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. 222. The article movement system of claim 200, wherein the shell includes an upwardly extending neck connected to the article. 223. The article movement system of claim 222, 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. 224. The article movement system of claim 223, wherein the suspension unit is removable from the neck as a single unit. 225. The article movement system of claim 222, 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. 226. The article movement system of claim 225, wherein the brake unit is removable from the neck as a single unit. 227. The article movement system of claim 225, 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.