Patent Application
20060005351
The present invention relates to a rolling support device and especially to a vertically oriented omni-directional rolling support device capable of highly accurate placement.
The typical rolling support for furniture has traditionally been an offset caster. The presence of offset casters can make it difficult to accurately place an article of furniture since the caster can change orientation during movement causing the center of balance to shift. When a heavy item is placed on such a caster, it is difficult to change directions, especially in tight spaces, and often it is not possible to accurately place the furniture precisely in a desired location.
An individual moving such a piece of furniture supported by traditional casters will often encounter the problem where placement control is not accurate. The individual attempts to move the furniture a small distance in one direction only to find that the caster has changed position, and the furniture has shifted undesirably. Thus, the industry still requires an accurately placed, omni-directional rolling support for furniture or other articles without undue movement caused by caster reorientation.
The present invention, as defined in the claims, overcomes these disadvantages by describing an omni-directional rolling support that is aligned along a vertical axis, so that the furniture item may be easily moved over the horizontal surface, and accurately placed, without incurring a shift due to the reorientation of an offset caster. Further, once the furniture item is positioned, a hollow support unit can be used to contact the surface around the rolling support to lock the furniture item in place.
According to a preferred embodiment, a cup is attached to a first end of a shaft. The cup receives a ball that is in sliding contact with the cup inner surface. The ball is in non-sliding contact with a planar surface so a supported object, such as a furniture leg, attached to the second end of the shaft. Thus, the supported object is supported against the planar surface to roll on the ball across the planar surface in any direction. The shaft can be threaded for mating with a nut or other threaded member. The position of the furniture leg relative to the cup member may be adjusted by positioning the nut on the threaded shaft.
A hollow support unit has an open end and a closed end, the close end can be attached to the shaft and the open end is surrounding the cup. The hollow support unit can extend and retract along a central axis so that when the hollow support unit is extended, it contacts the planar surface and inhibits rolling movement along the planar surface. The hollow support unit is preferably cylindrical in shape.
The exact nature of this invention, as well as the objects and advantages thereof, will become readily apparent upon consideration of the following specification in conjunction with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:
Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the intention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.
Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.
In reference to
The cup 102 receives a ball 106, and the ball 106 is retained in the cup 102. The ends of the cup 102 extend around the received ball 106 beyond the horizontal midline 112 of the ball so that the ball 106 is retained in the cup 102 after insertion. The cup 102 may be composed of metal or hard plastic while the ball 106 may be composed of plastic, TEFLON (R), or metal. The ball 106 is positioned in the cup 102 between the cup 102 and a planar surface such as a floor. The ball 106 is in sliding contact with the cup 102 inner surface 114 while the ball is in non-sliding contact with the planar surface.
The coefficient of static friction between the ball 106 and the planar surface is higher than the coefficient of static friction between the ball 106 and the cup 102 inner surface 114. Therefore, even from a rest position, the ball 106 is in sliding contact with the cup 102 inner surface 114, and in non-sliding contact with the planar surface to provide omni-directional rolling support for a supported object attached to the shaft 104 across the planar surface. The cup 102 is rotationally fixed relative to the shaft 104 so that when changing the direction of movement across the planar surface, the shaft 104 and cup 102 do not rotate. This allows accurate placement of an article of furniture, for example, and eliminates undue movement caused by off-set caster reorientation.
In one embodiment, a plurality of small-diameter spheres 116 are positioned between the ball 106 and the cup 102 inner surface 114, and occupy the corners of a shoulder-like circular cavity 118 positioned radially in proximity to the closed end of the cup 102, as shown in
In one embodiment, the shaft 104 is treaded for mating with a complimentarily threaded member such as a nut 108 or other threaded member for engaging with the threaded shaft 104, for example. If a nut 108 is mounted on the shaft 104, the position of the nut on the shaft 104 determines the position of a supported object relative to the cup 102, and essentially determines the height of the supported object relative to a horizontal surface when the omni-directional rolling support device is oriented vertically over the horizontal surface.
In reference to
Alternatively, when the nut 108 is rotated about the shaft 104 in a second direction, the nut 108 retreats away from the cup 102 and the shaft 104 moves in a direction 214 out of the cavity 104. Thus, a nut 108 mounted on the threaded shaft 104 may be used in adjusting the height of the supported portion of a furniture leg 202, for example. The nut 108 has a first side and a second side, the first side of the nut 108 is oriented towards the cup 102 (proximal) while the second side of the nut 108 is oriented away from the cup 102 (distal) and toward the furniture leg 202.
A washer 210 may optionally be located between the nut 108 second side and the furniture leg 202. The nut 108 can be adjusted to both adjust the height of the furniture as well as to level an article of furniture having more than one leg. Alternatively, the shaft 104 may be smooth, not threaded, and can maintain an adjustable height for the furniture leg 202 based the addition of a properly sized spacer, or a plurality of spacers such as the washer 210 inserted on the shaft and between the cup 102 and the furniture leg 202.
In reference to
An optional second washer 310 is placed over the threaded shaft 104 and adjacent to the top surface of the planar portion 302 and the second nut 308 is tightened on the threaded shaft 104. The first nut 108 and the second nut 308 are counter rotated against each other so the first nut 108 and the second nut 308 advance towards each other in order to securely hold the planar portion 302 of the supported object between them. The planar portion 302 can also be within a furniture leg 202 so that the omni-directional rolling support device 100 is held securely within the furniture leg 202. It is understood that the furniture leg 202 must also include an opening for inserting the second nut 308 as well as an optional washer 310 and to allow tightening of the second nut 308.
In reference to
In reference to
A frictional member 508 may be attached on the underside of the hollow support unit 502 on a contact ring 510 in order to provide added friction between the planar surface 504 and the contact ring 510 hollow support unit 502. The frictional member 508 may include a butyl rubber material, for example. The hollow support unit 502 in the presently preferred embodiment includes an outer cylinder 512, a threaded contact ring 510, and a threaded top cap 516.
The outer cylinder 512 has a threaded inner portion (not shown) that mates with the threaded portions on the contact ring 510 and the threaded top cap 516 that the hollow support unit 502 can expand or contract along the central axis when the outer cylinder 512, contact ring 510, and the top cap 516 are rotated relative to each other. Either or both of the contact ring 510 and the top cap 516 may be extended relative to the outer cylinder 512.
The hollow support unit 502 preferably includes an alloy DURALUMIN, but may be composed of aluminum alloy or another suitable, high tensile-strength material. Duralumin is a particular alloy of aluminum (over 90%) with copper (about 4%), magnesium (0.5%-1%), and manganese (less than 1%). Before a final heat treatment the duralumin alloy is ductile and malleable, but after the heat treatment a reaction between the aluminum and magnesium produces an increased hardness and tensile strength. Because it is light weight and durable, duralumin is widely used in the aircraft industry.
In one alternative embodiment, the cross-sectional view as in
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the amended claims, the invention may be practiced other than as specifically described herein.
