Omnidirectional spherical roller caster

Abstract

A caster capable of omnidirectional transport having a spherical roller freely mounted within a housing having a concave spherical cavity. A plurality of cylindrical bores is disposed perpendicular to the inner concave surface in equilateral geometric configuration, axially converging toward the center of the cavity. A plurality of small internal caster assemblies, mounted for free independent rotation about the convergent axis, extend from within the bores to contact the spherical roller, thereby creating a loading surface capable of providing omnidirectional rotation. The spherical roller interfaces between the loading surface of the cavity and a surface onto which the entire caster assembly is imparted omnidirectional movement.

Description

[0001] 1. Field of the Invention[0002] The present invention relates generally to caster / roller systems, and is more particularly is directed toward a new and improved spherical roller caster system advantageous for omnidirectional movement over and against surfaces.[0003] 2. Description of Related Art[0004] 2.1 Casters and Rollers[0005] Casters are very ancient, and rollers even more so, possibly even preceding the wheel. Rollers support unidirectional rolling movement. Casters support ominidirectional rolling movement, but at a price. Once aligned in the desired direction of movement, a caster presents but little rolling resistance, and essentially serves as a roller or wheel. However, if a caster is not properly aligned for rolling movement in a new direction then the caster must "swing around" its pivot axis until the correct rolling alignment is assumed. This swinging motion involves a slipping and a sliding, as opposed to a rolling, of the wheel of the caster. This swinging mo...

AI Technical Summary

Benefits of technology

[0033] Another object of this invention is to provide transport systems of simple, low-cost construction capable of this free-form, but controllable action.

[0034] Yet another important object of the present invention is to bring an unrestricted freedom of movement in sport, as best exemplified by snowboarding, to skateboarding over warm, dry surfaces, without the necessity of snow or of waiting for appropriate seasons to practice this free movement.

[0035] Further objects relative to the skateboard are: to provide the ability to turn rapidly, or "carve," when leaning to one side, to provide the ability to instantly shift into a mode of omnidirectional behavior, easily travelling forwards, backwards, sideways or various combinations thereof, to provide the ability to transition smoothly and controllably between carving and the omnidirectional mode, to provide a skater an interface between his board and the surface on which he rides that imitates characteristics of a snowboard, where the omnidirectional mode is engaged when weight is relatively evenly distributed across the board and exited by transferring weight to the board's edge, to provide the ability to perform partial or complete rotation, repeatedly, while skateboarding, without lifting, while in motion, to provide the ability to ride on different types of terrain, including paved surfaces, tile and wood floor, ice, fabric and dirt by making simple adjustments. Such a device must be economical to produce and sell, so that anyone may enjoy its advantages.

[0041] Importantly to the caster's support of omnidirectional movement, the offset of each shaft and of the wheel that is supported by that shaft from the converging axis of the associated imaginary bore makes that such force moment as is developed upon changing rotational direction of the sphere causes may cause rotation of the annular bearing of one or more of the assemblies. It is (i) this offset, and (ii) this rotation, in the support of the rotating sphere of the caster that facilitates that any all changes in rotational direction transpire smoothly, and without any appreciable differentiation. The caster is truly omnidirectional. The sphere or spherical roller can be contained and supported within the housing by a removable annular retainer. Thus, the containing and supporting is comprised of a set of small caster assemblies providing load-bearing interfaces between the concave regions outlining the spherical cavity and the spherical rollers, thereby providing multidirectional movement capability. Also contemplated is a self-lubricating annular lip on the retainer surface circumscribing the opening and disposed within a plane distal from the equator of the roller.

Problems solved by technology

This swinging motion is typically at a much greater frictional loss than rolling, thus causing loss of energy.

This resistance can cause jerky, spasmodic, imprecise, and energy intensive initial motion of the load.

In other words, it is hard to get a stationary heavy load supported on casters initially improperly aligned to the desired direction of movement to commence movement in the desired direction, let alone to smoothly do so.

However, the exposed rolling surface of the sphere may pick up such contamination from the surfaces, normally a floor, over and on which rolling is performed as does, when later rolled into the supportive cavity, cause increased frictional resistance.

The problem is that such a structure simply moves the frictional scrubbing an misalignment problem to another, lower, level, dictating that even the spherical ball roller caster will at least initially present a higher rolling resistance in some directions than in others.

Unfortunately, the predominant part of world has no snow, or has long periods without snow.

Common paired-wheel roller skates, known and manufactured for many years, can move either forward or backward only in a straight line, but these roller skates cannot rotate and spin like figure skates.

Additionally, because of this wheel arrangement, it is difficult for a roller skater to lean left or right, in order to pivot or negotiate tight curves.

Conventional in-line skates having single in-line wheels simulate the feel and motion of ice skating, but do not achieve the apparently free movement of figure ice skates.

However, because the wheels are mounted on horizontal shafts, the roller blades cannot rotate and spin like ice skates.

These combinations are not desired from the standpoint of too much friction or too little control.

The configuration of this skate mechanism is very complex and cumbersome, costly to manufacture and repair, and control in other applications is doubtful.

While advances such as urethane wheels, kicktails, laminated wood decks, precision bearings, griptape and concave decks have offered better control, they have not changed the motion characteristics, relying instead on straining riders' athletic ability to squeeze new performance limits from existing equipment.

This is a very difficult and dangerous maneuver, requiring high speed-generated momentum to overcome friction of the wheels as the riders pushed their boards far out in front of their bodies, necessitating the use of heavily padded gloves to protect their hands while leaning and dragging on the passing pavement.

Because powersliding requires the rider to travel fully sideways, the subtle moves available on a snowboard are virtually unachievable.

Of related art examples proffering true lateral motion, U.S. Pat. No. 5,312,258 to Giorgio, 1994, uses an array of ball-type roller bearings on a constructed half pipe, however, his device does not include means for controlling the omnidirectional motion.

U.S. Pat. No. 3,827,706 to Milliman, 1974, uses a combination of pivoting casters and fixed wheels, the casters disposed slightly closer to the ground than the fixed wheels, allowing a skier to angle the ski in and out of a sliding mode; however, no means is provided to stabilize the casters or to smooth the transitions as weight is transferred from a pivoting caster to a fixed caster.

Shols, 1989, describes a bias by a hinge means and a compliant mounting surface; however, this configuration does not permit more than one direction of bias, allows wobbling and does little to help the rider get back into the straight-ahead position.

However, the wheels are limited to forward and lateral movement at a direction roughly perpendicular to the forward movement, but not at any angular movement at angles between 0 and 90 degrees off from the forward direction.

The omnidirectional nature of the vehicle made provision of other suspension systems difficult.

In addition, the cumbersome design of these prior art omnidirectional vehicles rendered them inapplicable to skates skateboards, wheelchairs, omnidirectional conveyor platforms, and the like, in which all of the propulsion, suspension, and control must be situated in a relatively small area beneath the user or seat of a chair.

All of the single axis wheels can only rotate in one plane, except for the complicated devices with further, complicated single bearings built into the circumference of the larger single axis wheel.

These arragements result in "scuffing," which creates considerable friction and load on the wheels.

Therefore, there is a need for a spherical roller caster system of simple design, simple maintenance, inexpensive to build and repair, and hitherto unobtainable omnidirectional movement.

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