GB1570285A

GB1570285A - Castors

Info

Publication number: GB1570285A
Application number: GB4843175A
Authority: GB
Original assignee: Guy Raymond Engineering Co Ltd
Current assignee: Guy Raymond Engineering Co Ltd
Priority date: 1975-11-25
Filing date: 1975-11-25
Publication date: 1980-06-25
Also published as: DE7636964U1

Description

(54) IMPROVEMENTS IN AND RELATING TO CASTORS (71) We, GUY-RAYMOND ENGINEERING COMPANY LIMITED, a British company of Rollesby Road, Hardwick Industrial Estate, King's Lynn, Norfolk PE30 4LX, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a castor assembly which allows for adjustment of the height of an article of furniture supported by the castor assembly.

We have found that there is a need in the furniture industry for a castor which allows the height of the article of furniture to which the castor is attached to be adjusted from a position in which the article of furniture rests on the ground and is immovable into a position in which the article of furniture is raised above ground level and can be freely moved on the castor or castors.

It has become common practice in the furniture industry to design a series of matching units such as cupboards and chests which are intended to be positioned alongside one another with their upper surfaces aligned to form a continuous working surface. It will be appreciated that it is of the utmost importance, in this type of arrangement that the units can be easily and accurately aligned one with the other.

In order to meet these requirements, the present invention provides a castor assembly comprising a castor wheel or wheels mounted on a castor body, a vertical spigot mounted in a bore in the castor body and freely rotatable relative to the castor body, a screw thread on a portion of the spigot projecting from the castor body and bush which is provided with means for attachment to an article of furniture threadedly mounted on the projecting end of the spigot, wherein the spigot is provided with means adapted to co-operate with a torque transmitting tool for rotation of the spigot relative to the bush for adjustment to their relative axial positions and the functional resistance to rotation between the spigot and the bush is greater than between the spigot and the castor body.

A preferred form of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a front elevation partly in section of a castor assembly according to the present invention; Figure 2 is a side elevation partly in section of the castor assembly shown in Figure 1; Figure 3 is a side elevation partly in section showing the castor assembly of Figures 1 and 2 attached to an article of furniture, with the article of furniture resting on the ground; and Figure 4 is a view similar to Figure 3 showing the article of furniture raised so that it is clear of the ground.

In the drawings a castor is indicated generally at 10 which comprises a castor body 11 of generally cruciform shape formed by a vertical tubular portion 12 and a horizontal tubular portion 13. The tubular portion 12 has an upwardly open vertical bore 14 and the tubular portion 13 has a horizontal through bore 15. An axle 16 extends through the horizontal bore 15 and similar wheels 17 and 18 are mounted on opposite ends of the axle 16. The opposite ends of the axle 16 are formed with portions which initially project beyond each wheel and each wheel is formed with a tapered countersunk recess 20. In order to mount the wheels on the axle 16, the projecting ends of the axle are turned over into the recesses 20 to lock the wheels on the axle. The wheels 17 and 18 are preferably injection moulded from a suitable synthetic plastics material.

A spigot 22 is mounted in the bore 14 so as to project upwardly from the castor body 11. The bottom end of the spigot 22 is formed with an annular groove 23. A rib 24 is formed in the wall of the bore 14 and the rib 24 snap-engages into the groove 23 to retain the spigot 22 within the castor body. An upper portion 25 of the spigot 22, which projects above the castor body, is threaded to engage in a bush 26.

The bush 26 is internally threaded over a part of its length and is generally cylindrical. An annular flange 27 is formed at the bottom end of the bush and is provided with a plurality of through apertures 28 which enable the flange to be non-rotatably mounted on a flat surface such as the underside of an article of furniture. The upper end face of the spigot 22 is formed with a slot 29 to receive a screwdriver. The spigot 22 is sufficiently freely rotatable in the bore 14 of the castor body 11 that rotation of the spigot 22 relative to the bush 26 causes the bush to ride up the threaded portion of the spigot 22, whereas rotation of the castor body will not cause rotation of the spigot relative to the bush.

In use, the castor 10 is mounted on the under surface of an article of furniture only a part of which is shown in Figures 3 and 4. The article of furniture comprises a plinth 30 having a horizontal floor panel 31 and sidewalls 32 only one of which is shown in the drawings. A stiffening strut 33 is provided on the under surface of the floor panel 31 and a bore 34 is formed in the strut 33 of a diameter sufficient to receive the sleeve 27 of the bush 26 as a close snug fit.

The bush 26 is attached to the plinth 30 by inserting the sleeve 27 into the bore 34 and mounting the flange 28 on the upper surface of the strut 33 with pins 35 or screws. The floor panel 31 is formed with a throughbore 36 which is coaxial with the bore 34 in the strut 33 and the upper end of the spigot 22 can project upwardly into the bore 36 when the bush is mounted on the floor panel 31. The upper end of the spigot 22 is a close fit in the bore 36 so that the bore centralises the spigot relative to the floor panel 31.

In the position shown in Figure 3 in which the spigot 22 has been rotated to draw the castor body 11 upwardly against the bush 26, the castor body and the wheels 17 and 18 are wholly contained within the depth of the side walls 32 of the plinth 30 so that the side walls rest on the ground.

If it is desired to move the article of furniture, a screwdriver is inserted into the slot 29 in the upper end of the spigot 22 and the spigot is rotated so as to move the spigot and castor body 11 downwardly through the bush 26 until the wheels engage the ground.

Further rotation of the spigot then causes the bush to ride up the spigot carrying the article of furniture upwardly until the side walls are clear of the ground. The article of furniture can then be moved on the castor 10 with a minimum of effort.

It will be appreciated that, although only one castor is shown in Figures 3 and 4 an article of furniture will require a number of castors to ensure free rolling movement of the article along the ground. If it is necessary to make adjustments to the height of the article of furniture, this can be done quickly and easily by rotating the spigot of each castor in turn until the correct height has been achieved. This enables a row of articles of furniture to be aligned in a vertical sense, very quickly and easily.

It will be seen from Figure 3 that access to the screwdriver slot 29 in the upper end of the spigot 22 is achieved quickly and easily through the bore 35.

As an alternative means of rotating the spigot 22, the spigot can be provided with an integral hexagonal nut at a position immediately adjacent the castor body 11. A spanner can then be used to turn the spigot and raise the bush.

It will also be understood that various other forms of castor may be provided and in particular that the transverse wheel axle may be arranged directly beneath the vertical spigot axis.

The castor body, the wheels and the bush are preferably injection moulded from a synthetic plastics material such as nylon and the spigot and axle are preferably formed from steel.

The bore of the bush 26 is preferably threaded over only a part of its length so as to minimise any risk of the bush binding on the spigot. The unthreaded plain portion of the bore in the bush is preferably a friction fit on the threaded portion of the spigot to minimise tilting of the spigot relative to the bush and to resist accidental rotation of the spigot relative to the bush.

WHAT WE CLAIM IS: 1. A castor assembly comprising a castor wheel or wheels mounted on a castor body, vertical spigot mounted in a bore in the castor body and freely rotatable relative to the castor body, a screw thread on a portion of the spigot projecting from the castor body and a bush which is provided with means for attachment to an article of furniture threadedly mounted on the protecting end of the spigot, wherein the spigot is provided with means adapted to co-operate with a torque transmitting tool for rotation of the spigot relative to the bush for adjustment of their relative axial positions and the frictional resistance to rotation between the spigot and the bush is greater than between the spigot and the castor body.

2. A castor assembly as claimed in claim 1, wherein the spigot is formed with a slot in an end face to receive a screwdriver.

3. A castor assembly as claimed in claim 1 or claim 2, wherein the spigot is formed with an integral nut adjacent the castor body.

4. A castor assembly as claimed in any preceding claim, wherein the bush comprises a sleeve portion and a circumferential flange

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The bush 26 is internally threaded over a part of its length and is generally cylindrical. An annular flange 27 is formed at the bottom end of the bush and is provided with a plurality of through apertures 28 which enable the flange to be non-rotatably mounted on a flat surface such as the underside of an article of furniture. The upper end face of the spigot 22 is formed with a slot 29 to receive a screwdriver. The spigot 22 is sufficiently freely rotatable in the bore 14 of the castor body 11 that rotation of the spigot 22 relative to the bush 26 causes the bush to ride up the threaded portion of the spigot 22, whereas rotation of the castor body will not cause rotation of the spigot relative to the bush. In use, the castor 10 is mounted on the under surface of an article of furniture only a part of which is shown in Figures 3 and 4. The article of furniture comprises a plinth 30 having a horizontal floor panel 31 and sidewalls 32 only one of which is shown in the drawings. A stiffening strut 33 is provided on the under surface of the floor panel 31 and a bore 34 is formed in the strut 33 of a diameter sufficient to receive the sleeve 27 of the bush 26 as a close snug fit. The bush 26 is attached to the plinth 30 by inserting the sleeve 27 into the bore 34 and mounting the flange 28 on the upper surface of the strut 33 with pins 35 or screws. The floor panel 31 is formed with a throughbore 36 which is coaxial with the bore 34 in the strut 33 and the upper end of the spigot 22 can project upwardly into the bore 36 when the bush is mounted on the floor panel 31. The upper end of the spigot 22 is a close fit in the bore 36 so that the bore centralises the spigot relative to the floor panel 31. In the position shown in Figure 3 in which the spigot 22 has been rotated to draw the castor body 11 upwardly against the bush 26, the castor body and the wheels 17 and 18 are wholly contained within the depth of the side walls 32 of the plinth 30 so that the side walls rest on the ground. If it is desired to move the article of furniture, a screwdriver is inserted into the slot 29 in the upper end of the spigot 22 and the spigot is rotated so as to move the spigot and castor body 11 downwardly through the bush 26 until the wheels engage the ground. Further rotation of the spigot then causes the bush to ride up the spigot carrying the article of furniture upwardly until the side walls are clear of the ground. The article of furniture can then be moved on the castor 10 with a minimum of effort. It will be appreciated that, although only one castor is shown in Figures 3 and 4 an article of furniture will require a number of castors to ensure free rolling movement of the article along the ground. If it is necessary to make adjustments to the height of the article of furniture, this can be done quickly and easily by rotating the spigot of each castor in turn until the correct height has been achieved. This enables a row of articles of furniture to be aligned in a vertical sense, very quickly and easily. It will be seen from Figure 3 that access to the screwdriver slot 29 in the upper end of the spigot 22 is achieved quickly and easily through the bore 35. As an alternative means of rotating the spigot 22, the spigot can be provided with an integral hexagonal nut at a position immediately adjacent the castor body 11. A spanner can then be used to turn the spigot and raise the bush. It will also be understood that various other forms of castor may be provided and in particular that the transverse wheel axle may be arranged directly beneath the vertical spigot axis. The castor body, the wheels and the bush are preferably injection moulded from a synthetic plastics material such as nylon and the spigot and axle are preferably formed from steel. The bore of the bush 26 is preferably threaded over only a part of its length so as to minimise any risk of the bush binding on the spigot. The unthreaded plain portion of the bore in the bush is preferably a friction fit on the threaded portion of the spigot to minimise tilting of the spigot relative to the bush and to resist accidental rotation of the spigot relative to the bush. WHAT WE CLAIM IS:

1. A castor assembly comprising a castor wheel or wheels mounted on a castor body, vertical spigot mounted in a bore in the castor body and freely rotatable relative to the castor body, a screw thread on a portion of the spigot projecting from the castor body and a bush which is provided with means for attachment to an article of furniture threadedly mounted on the protecting end of the spigot, wherein the spigot is provided with means adapted to co-operate with a torque transmitting tool for rotation of the spigot relative to the bush for adjustment of their relative axial positions and the frictional resistance to rotation between the spigot and the bush is greater than between the spigot and the castor body.

at one end of the sleeve portion, the sleeve being adapted to be located in a bore in an article of furniture and the flange being adapted to abut a face of the article of furniture and be attached thereto.

5. An article of furniture mounted on a plurality of castor assemblies each as claimed in any preceding claim, wherein the bush of each castor assembly is attached to the article of furniture and the spigot is threadedly engaged in the bush, the arrangement being such that relative movement of the spigot through the bush results in adjustment of the height of the article of furniture from the ground.

6. An article of furniture as claimed in Claim 5, wherein the spigot of each castor assembly projects through the bush and extends as a close fit into a bore formed in a part of the article of furniture.

7. An article of furniture as claimed in Claim 5 or Claim 6, wherein the castor assemblies are mounted on the article in a recess, the depth of the recess being such that each castor assembly is movable by rotation of the spigot from a position in which the castor wheel is clear of the ground and the article rests on the ground into a position in which the castor wheel rests on the ground and supports the article.

8. A castor assembly substantially as described herein with reference to the accompanying drawings.

9. An article of furniture mounted on a plurality of castor assemblies substantially as described herein with reference to the accompanying drawings.