WO2018158770A1

WO2018158770A1 - Retractable ball caster

Info

Publication number: WO2018158770A1
Application number: PCT/IL2018/050227
Authority: WO
Inventors: Shlomo AHARON
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-03-01
Filing date: 2018-02-28
Publication date: 2018-09-07
Anticipated expiration: 2019-09-01
Also published as: IL250854A0

Abstract

A retractable ball caster device comprising a lug housing, a pivotable ball, which is mounted in the lug housing, a plurality of ball bearings, which are contained within the lug housing and contact the pivotable ball to allow its low friction rotation, and a motion mechanism that allows extension and retraction of the pivotable ball from the lug housing.

Description

RETRACTABLE BALL CASTER

FIELD OF THE INVENTION

The present invention relates to a new device for converting stationary objects, for example furniture, into easily movable objects, when desired, by attaching a retractable ball caster to the object.

BACKGROUND OF THE INVENTION

The prior art describes pivotal roller mechanisms for use in statically supporting an item upon a surface in such fashion as to be able to move it at some desired time. Some of the variations related to ball casters and retractable casters are detailed in the following review.

Wheels have been used for centuries to provide motion to otherwise difficult-to-move objects. Where the primary purpose of the object is not its ability to change position, for example furniture, in order to assist motion of non-transport type objects, smaller wheels, such as caster wheels, have been developed to be attached to the underside of such objects.

As the primary usage of such objects is in their stationary mode, different devices have been developed to assist the change of mode from stationary to mobile and vice versa.

In US Patent No. 3,934304 to Takahashi, a swivel caster I rotary wheel is used to provide an object rolling mobility in one mode and to be stationary in another, by simply modifying the position of the wheel with respect to the ground.

Another form of caster braking is seen in U.S. Patent No. 6,854,568 to Kun- Tsai, where the inventor describes a caster braking device to be attached to a standard wheel caster. Devices such as this provide users the option to stop the rolling motion of the caster when desired. Unfortunately such designs are neither aesthetically pleasing as the caster remains in full view, nor does the wheel provide easy multidirectional motion due to its bidirectional nature.

In U.S. Patent No. 6,473,935 to H. Cherukuri, the inventor describes a retractable roller mechanism. This mechanism consists of a wheel shaped roller which retracts into a housing. This device succeeds in providing the aesthetic benefits of not appearing to be a caster, in the object's stationary mode, while providing the static and dynamic states for the supported object, however, it still does not provide easy multidirectional motion due to the bidirectional nature of a wheel. Therefore, the desire for more maneuverable multi-directional motion has caused inventors to turn to the use of ball casters in place of wheel casters, which have lower friction when changing direction along a surface. However the challenge of providing an aesthetic and effective braking system has had to be developed again due to the inherent differences between spherical rollers and wheel shaped rollers.

In U.S. Patent No. 4,402,108 to H. U. Pannwitz, the inventor describes a ball caster, and ball bearing, system mounted inside a housing body in the shape of a hemispherical socket. The inventor utilizes this design to convert a stationary load, for example furniture, to a mobile object by attaching said ball casters to the legs or undersides of such a load. The braking system is engaged by providing increased pressure from the direction of the load. While this device has sought to limit disadvantages of such ball casters such as the entry of unwanted foreign substances into the ball housing it still does not switch to the object's stationary mode until additional force is applied from the direction of the object onto the caster.

Another example of such a ball caster is shown in U.S. Patent No. 3,096,536 to

N.A. Rabelos, in which a retractable ball caster is utilized to elevate and mobilize light loads such as chairs. This device succeeds in improving the aesthetic quality of the device by partially hiding the caster in the stationary mode however it can only engage this mode when pressure is applied to the load allowing the ball caster( s) to recede partially into the load's structure restricting movement once the caster's housing contacts the floor. When the pressure is removed, for example by a person standing up, springs cause the ball casters to resume their fully protruding positions. This design is limited in that it provides no breaking adjustment and allows the load to be mobile at all times other than when pressure is applied to it.

Based on a review of the prior art, it becomes quite evident that each of the approaches employed in the past suffered from shortcomings of some sort or another. Devices using load or pressure based braking systems restrict the option to choose when the load is a stationary object. Current retractable systems do not adequately address the issue of foreign substances reducing efficiency.

Therefore, it would be desirable to provide a caster mechanism which incorporates a braking system that is not reliant on increased pressure on the load and yet still provides the benefits of being aesthetic, able to be easily moved in a multidirectional manner, fully retractable, inexpensive to manufacture and service, easily operable under significant loads, and can withstand such loading requirements. SUMMARY OF THE INVENTION

Accordingly, it is a principal object of the present invention to overcome the above-mentioned disadvantages and provide a superior device in the form of a retractable ball caster device enabling low friction multi-directional motion of an otherwise not easily movable object. This device is intended to act as an interposition between a normally stationary load and another surface.

In accordance with one embodiment of the present invention, there is provided a retractable ball caster comprising:

a lug housing; and

a pivotable ball which is mounted in said lug housing; and

a plurality of ball bearings which are contained within said lug housing and contact said pivotable ball to provide it with low friction rotation; and

a motion mechanism that allows extension and retraction of said pivotable ball from said lug housing.

In one embodiment, the device is comprised of a sliding lug mounted inside a cylindrical lug housing. Mounted inside the lug is a hemispherical ball bearing cover which contains a plurality of ball bearings. A pivotable ball is mounted inside the ball bearing cover and protrudes partially from the lug. The ball bearings inside the ball bearing cover are interposed between the ball bearing cover and the pivotable ball allowing the pivotable ball low-friction rotational motion. A retaining ring is fastened to the end of the lug, which has the pivotable ball protruding from it, and retains the ball bearing cover and pivotable balls in position inside the lug.

An eccentric cam is located inside the lug housing next to the sliding lug. The eccentric cam is mounted on an axle that is slightly longer than the diameter of the lug housing. The axle is mounted inside the lug housing along its diameter. The axle, which protrudes from two recesses in the lug housing, is secured, externally, at one end by an axle lock and at the other end by a lever.

The lug housing is designed to be attached to an object as an intermediary between the object and another surface upon which it rests. When the lever is rotated approximately 90 degrees, the eccentric cam rotates and causes the lug to be displaced a certain distance parallel to the length of the lug housing. This displacement, dependent on the direction of lever rotation, causes the pivotable ball to be positioned either completely inside or protruding from the lug housing. When the pivotable ball is positioned inside the main housing, the circular lower rim of the lug housing is the intended contact point with the outside surface. The contact between the lug housing and the surface is one of relatively high friction. As a result the object cannot be easily moved along this surface and a braking effect has been produced. When the pivotable ball is found to be protruding from the lug housing it becomes the contact point with the surface upon which the object rests. The pivotable ball which rotates easily within the lug allows the object to be rolled along the surface upon which it rests with extremely little force.

The pivotable ball and the ball bearings may be made of plastic, composite or other materials. It is desirable that such materials are used as they provide a self- lubrication effect in order to add to the effectiveness of the device.

The ball bearings may be coated with grease, graphite or other lubricating materials to reduce dust and other unwanted substances reducing device efficiency.

There is designed a close clearance between the pivotable ball and the retaining ring. This provides protection for the device against dust and other unwanted substances entering the device.

The torque provided by rotation of the lever provides a significant force reduction needed to extend the device than would otherwise be needed to lift the load under which the device is located.

The construction of the device allows it to be used at any angle of inclination given that the lower rim of the main housing is perpendicular to the contact surface.

The device can be configured to be operated manually or by an engine, which for example can be an electrical or hydraulic engine. The engine can be configured to be remotely controlled. When a number of such devices is used e.g. in a furniture item having a corresponding number of legs, each device being mounted to one of the legs, all the devices can be operated simultaneously by a single controller.

Additional features and advantages of the invention will become apparent from the following drawings and descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention with regard to the embodiments thereof, reference is made to the accompanying drawings, in which like numerals designate corresponding elements or sections throughout. Fig. 1 is a perspective view of a retractable ball caster device, in its fully retracted position, constructed and operated in accordance with the principles of the invention;

Fig. 2 is a cross-sectional view of the retractable ball caster device, taken along section lines A-A of Fig. 1 ;

Fig. 3 is an exploded view of the retractable ball caster device, shown in Fig. 1;

Fig. 4 is a perspective cross-sectional view of the retractable ball caster device, in the fully retracted mode, taken along section lines B-B of Fig. 1 ; and

Fig. 5 is a perspective cross-sectional view of the retractable ball caster device, in the fully extended mode, taken along section lines B-B of Fig. 1 .

DETAILED DESCRIPTION OF EMBODIMENTS

Referring now to Fig. 1, there is shown a perspective view of one embodiment of a fully extendable I retractable, retractable ball caster device 10, constructed in accordance with the principles of the present invention. The device 10 comprises a lug housing 12, which is of a cylindrical nature. Located at the top of the lug housing 12 are a plurality of recesses 14 which are designed to accommodate standard screws or adaptors. A lever 16 is aligned with the length of the lug housing 12. When the lever 16 is rotated approximately 90 degrees an internal motion mechanism enables a sliding lug 24 (not shown) with a protruding pivotable ball 30 (not shown) to protrude from the lug housing 12.

Referrin now to Fig. 2, there is shown a cross sectional view of the retractable ball caster device, taken along section lines A-A of Fig. 1 . In this view an axle lock 18 can be seen fitted in the side of the lug housing 12. The axle 20, formed with a square cross section, and whose length is perpendicular to the length of the lever 16, is mounted within the lug housing 12 and protrudes from two of the lug housing's circular openings 17. The lever 16 and the axle lock 18 are both fastened to opposite ends of an axle 20 securing its position within the lug housing 12.

An eccentric cam 22 is formed with shoulders 19 and is fitted onto the axle 20. Shoulders 1 are seated so as to be rotatable within a pair of retaining slots 25 forming a cradle on the underside of the top of lug housing 12. The square cross section of the axle 20 is a close fit to a square orifice 21 formed in the eccentric cam 22, within which it is inserted. Sliding lug 24 is located beneath eccentric cam 22, both of which are mounted inside lug housing 12. Located in the upper central edge of lug 24 is a plurality of tracks. In this embodiment of the device the lug has a track 23 with which the lower edge of eccentric cam 22 is in contact and is aligned.

A hemispherical ball bearing cover 26 is mounted inside lug housing 24. The ball bearing cover 26 houses a plurality of evenly distributed ball bearings 28. A large pivotable bal l 30 contacts ball bearings 28 and is also partially contained within ball bearing cover 26. The ball bearings 28 act as an interposition between ball bearing cover 26 and pivotable ball 30 providing pivotable ball 30 the ability to rotate with minimal factional resistance. A retaining ring 32 is fastened to a circular recess on the lower edge of lug 24 and has an inner diameter smaller than pivotable ball 30 which partially protrudes from it. The retaining ring 32 serves to retain the positions of pivotable ball 30. ball bearings 28 and ball bearing cover 26 within sliding lug 24.

Referring now to Fig. 3, there is shown an exploded view of device 10 shown m Fig. 1 . This view provides a clearer understanding of the elements and their relative position with respect to each olher. The intended pattern for ball bearings 28, with regard to this embodiment of device 10, can be more clearly seen to cover pivotable hall 30 from multiple angles.

Referring now to Fig. 4, there is shown a perspective cross-sectional view of device 10. in the fully retracted mode, taken along section lines B-B of Fig. 1 . In this view, the assembled positions of several of the elements described in Fig. 2 are more clearly seen. The approximate depth of recess 14 is shown. The eccentric cam 22 is shown to rest on track 23 of lug 24 in the fully retracted position of device 10. The square orifice 21 in eccentric cam 22 within which axle 20 is inserted is also seen more clearly, as is axle 20 itself in the fitted position. The inner diameter of retaining ring 32 is seen to be positioned in a close fit around the lower side of pivotable ball 30. It is also shown how retaining ring 32 is attached to the lower end of lug 24 and holds ball bearings 28 and pivotable ball 30 in position within lug 24 independent of lug housing 12. It can also be seen that the lower edge 33 of lug housing 12 is in contact with external surface 34.

Referring now to Fig. 5, there is shown a perspective cross-sectional view of the device 10, in the fully extended mode, taken along section lines B-B of Fig. 1 . In this view, eccentric cam 22 has been rotated approximately 90 degrees clockwise and has subsequently displaced lug 24. The lug 24 has slid down inside lug housing 12 and now the pivotable ball 30 has become the singular contact point with external surface 34.

In operation, a plurality of devices 10 are mounted to the legs or side of a load, for example, the legs of an item of furniture, such that devices 10 become the only contact points between the load and the surface that the load is pressing against, for example, the floor.

In its fully retracted position, device 10 contacts surface 34 at lower edge 33 of lug housing 12, and provides a braking effect due to the factional force needed to move the device 10 along the surface. As a result the load is relatively stationary.

To change the device 10 from its retracted position, lever 16 of device 10 is rotated to a certain angle, and as a result, eccentric cam 22 rotates and displaces lug 24 so that pivoiable ball 30 now becomes the contact point of the load with the surface it is pressing against. A stopper (not shown) formed on the underside of the top of lug housing 12 prevents eccentric cam 22 from being rotated to an angle where the device is not in one of the fully extended or retracted positions. The low-friction construction of pivotable ball 30 and ball bearings 28 allows pivotable ball 30 to rotate easily. As pivotable ball 30 is now the contact point with external surface 34, the load can be moved in this dynamic mode with a relatively small force applied to the load in any direction roughly parallel to the surface. This mode allows easily movable motion of the load along the external surface it is pressed against.

After the load has been easily rolled to a new position, lever 16 can be rotated to its original position. This rotation causes eccentric cam 22 to be rotated allowing lug 24 to move within lug housing 12. The force on pivotable ball 30 from the external surface 34 due to the force of the load on device 10 will cause lug 24 to slide inside device 10, leaving lower edge 33 of lug housing 12 to become the primary contact point with external surface 34. Once again the load will revert to its stable stationary mode.

Having described the invention with regard to certain specific embodiments thereof, it is to be understood that the description is not meant as a limitation, since further modifications may now suggest themselves to those skilled in the art. and it is intended to cover such modifications as fall within the scope of the appended claims.

Claims

CLAIMS:

1. A retractable ball caster device comprising:

a lug housing;

a pivotable ball, which is mounted in said lug housing;

a plurality of ball bearings, which are contained within said lug housing and contact said pivotable ball to allow its low friction rotation; and

2. A device according to Claim 1 , wherein said rotation is multi-directional.

3. A device according to Claim 1 or 2, wherein the lug housing is a cylindrical lug housing and wherein the device comprises a sliding lug mounted inside the cylindrical lug housing.

4. A device according to Claim 3, wherein mounted inside the lug is a hemispherical ball bearing cover which contains the ball bearings.

5. A device according to Claim 4, wherein the pivotable ball is mounted inside the ball bearing cover and protrudes partially from the lug.

6. A device according to Claim 5, wherein the ball bearings inside the ball bearing cover are interposed between the ball bearing cover and the pivotable ball allowing the pivotable ball low-friction rotational motion.

7. A device according to Claim 5 or 6, wherein a retaining ring is fastened to the end of the lug, so that the pivotable ball protrudes therefrom, and so that the retaining ring retains the ball bearing cover and pivotable ball in position inside the lug.

8. A device according to any one of Claims 3 to 6, wherein an eccentric cam is located inside the lug housing next to the sliding lug.

9. A device according to Claim 8, wherein the eccentric cam is mounted on an axle that is slightly longer than the diameter of the lug housing and it has a lower edge, the lug being in contact and aligned with the lower edge of the eccentric cam so that rotation of the eccentric cam causes the lug to be move within lug housing.

10. A device according to any one of Claims 1 to 9, configured to be operated manually.

11. A device according to any one of Claims 1 to 9, configured to be operated by an engine.

12. A device according to Claim 11, wherein the engine is an electrical engine.

13. A device according to Claim 11 or 12, wherein the engine is configured to be remotely controlled.

14. A device according to any one of Claims 1 to 13, wherein the device is configured for use with an object designed to rest on a base surface, and wherein the lug housing is configured to be attached to the object so that displacement of the lug along the length of the lug housing causes the pivotable ball to move between its first position completely inside the lug housing and its second position, in which the ball protrudes from the lug housing.

15. A device according to Claim 14, wherein the lug housing has a lower rim configured to contact said base surface when the pivotable ball is positioned inside the lug housing, and wherein the pivotable ball protrudes from the lower rim of the lug housing towards the base surface to contact the base surface and prevent the lower rim from contacting the base surface, allowing the object to be rolled along the surface due to the pivotable ball being rotated within the lug housing.

16. A furniture item having at least two legs, each being provided with a retractable ball caster device according to any one of Claims 1 to 15.

17. A furniture item according to Claim 16, further comprising a controller configured to operate the devices of the legs simultaneously.