GB2182554A

GB2182554A - Spindle assembly

Info

Publication number: GB2182554A
Application number: GB08523270A
Authority: GB
Inventors: Raymond R J Daniels
Original assignee: Guy Raymond Engineering Co Ltd
Current assignee: Guy Raymond Engineering Co Ltd
Priority date: 1985-09-20
Filing date: 1985-09-20
Publication date: 1987-05-20
Also published as: GB8523270D0; GB2182554B

Abstract

An assembly of a plastics moulded article mounted for rotation on a spindle comprises castor 11 having a bore 14 which is closed at one end, an annular rib 15 in the wall of the bore and at least one gap (18) in the rib to allow the passage of fluid past the rib. The spindle 10 has a circumferential groove 12, 13 adjacent each end of the spindle so that either end of the spindle can be inserted into the bore and forced past the rib 15. The rib then locates in one of the grooves to retain the spindle in the bore, the other groove being adapted to receive a fastening member e.g. circlip 20 to attach the spindle to an article of furniture 19. Grease deposited at the closed end of bore 10 is forced by spindle 10 through the gap (18) to lubricate the assembly. <IMAGE>

Description

SPECIFICATION Spindle assembly The present invention is concerned with an assembly of a plastics moulded article mounted for rotation on a spindle and more particularly to a plastics moulded article such as a castor, roller or glide of the type used to support articles of furniture such as chairs, tables or desks.

It is well known to mount a castor on an article of furniture such as a chairwith the aid of a spindle, one end of which is inserted into a bore in the castor and the other end of which projects upwardly into the art icle offurniture where it is attached by a circlip or othersimilarfastening member.

Hitherto, spindles used for this purpose have been formed with a circumferential groove at one end to receiveacircliporsimilarfastening memberfor attaching the spindle two the article offurniture. The other end is adapted to be inserted into a bore in the castor in such a way that the castor is freely rotatable relative to the spindle, and has been retained within the bore in the castor in one of several different ways.

In one known construction, the spindle is a simple friction fit within the bore in the castor with the result that, when wear occurs, the castor may drop off the spindlewhenthe article offurniture is lifted. In an alternative construction, the spindle is provided with a ball bearing arrangement to ensure free rotation of the castor on the spindle. This construction is costly and also subjectto the castor coming away from the spindle when the bearing wears.

All ofthese known constructions have in common thefeature of a spindlewhich has one end formed with a groove to receive a circlip and the other end of some different construction for insertion in the bore in the castor. This means that, in order to automate the attachment ofthe circlip to the spindle, the spindle has to be oriented so that the grooved end is presented forthe attachment of the circlip and not the opposite end. As a result, the automatic attachment of the circlip to the spindle is a much more complex and expensive operation than would otherwise be necessary.

It is an object of the present invention to provide a spindle and a spindle assembly which facilitates automatic assembly of a circlip to one end of the spindle and which, atthe sametime, enablesthe other end ofthe spindle to be securely and rotatably attached within a bore in a moulded plastics article such as a castor or roller.

According to oneembodimentofthepresentin- vention we provided an assembly of a plastics moulded article mounted for rotation on a spindle, the plastics moulded article having a bore which is closed at one end, an annular rib in the wall ofthe bore adjacent the closed end and at least one gap in the ribto allowthe passage of fluid pastthe rib, and the spindle having a circumferential groove adjacent each end ofthe spindle, characterised in that the grooves are similar and equi-distantly spaced from the ends of the spindle whereby either end ofthe spindle can be inserted into the bore and forced past the rib so that the rib locates in one of the grooves to retain the spindle in the bore, the other groove being adapted to receive a fastening memberto attach the spindleto an article of furniture.

An embodiment of the invention will now be described with reference to the accompanying drawings, in which: Figure lisa view of a spindle with a circlip attached to one end of the spindle; Figure2 is an elevation in section of a part of a castor for an article of furniture; Figure 3 is a plan view of Figure 2; Figure 4 is an elevation, partly in section, showing a castor attached to an article offurniture with the aid ofthe spindle shown in Figure 1; and Figure5isaviewsimilarto Figure3 showing a further embodiment of the castor.

In the drawings a spindle is indicated generally at 10 and a castor at 11. The spindle 10 is formed from mild steel and is provided with two similar circum ferential grooves 12 and 13. The grooves 12 and 13 are equi-distantlyspaced from the ends of the spindle both ofwhich are chamfered to provide an easy lead in to a bore.

The castor 11 is formed from a suitable synthetic plastics material and is provided with a cylindrical bore 14formed with an annular rib 15, an end wall 16 and a recess 17 in the centre of the end wall. The distance between the rib 15 and the base 16 is marginally greaterthan the distance between each of the grooves 12 and 13 on the spindle and the adjacent end ofthe spindle. The rib 15 is formed with a gap 18, which can be seen clearly in Figure 3. The purpose of the gap 18 isto allowfluidto passtherib 15soasto minimise the build up of pressure atthe end ofthe bore 14 when the spindle is forced into the bore.

In an alternative embodiment, shown in Figure 5, a rib 15a is formed with two diametrically opposite gaps 1 8a and may, if desired be formed with three or more such gaps to facilitate the flow of air or grease past the rib.

In orderto mountthecastor 11 on an article of furniture 19,asshown in Figure4,acirclip20isfirst attached within one or other ofthe grooves 12 and 13, in the case ofthe spindle shown in Figure 1,the groove 12. This operation can be fully automated with a minimum of cost because both ends ofthe spindle 10 are identical and the circlip 20 can therefore be attached to either end.

When a circlip 20 has been attached to the spindle 10, the spindle is presented to the castor 11 and the other end of the spindle 10 which does not have the circlip attached to it is inserted into the bore 14. The end of the spindle is forced past the rib 15 until the rib locates in the groove 14to retain the spindle in the bore. As the end of the spindle is forced past the rib 15, air can escape pastthe ribthrough the gap 18so asto minimise any build up of pressure in the end of the bore. Thereafter, the castor can rotate freely on the spindle 10, the end wall 16 ofthe bore acting as a bearing surface for the end of the spindle. In some cases, the end ofthe spindle may be left with some raised metal at the centre of the end face ofthe spindle as a result ofthe machining process and this will locate in the recess 17 so as not to interfere with the free rotation of the castor about the spindle.

If required, a small quantity of grease may be deposited in the end of the bore before the spindle is inserted. The grease will then be forced by the spindle, which will act as a piston, back up between the interface between the spindle and the wall ofthe bore through the gap 18 in the rib 15 so as to spread over the whole ofthe interface between the spindle and the bore and lubricate the assembly.

When the spindle 10 is mounted in the bore 14,the castor can be attached to the article of furniture 19 by squeezing the circlip 20 and inserting the projecting end ofthe spindlethrough an aperture 21 in the article offurniture and into a recess 22 where the circlip can expand to lockthe spindle in place.

Claims

1. An assembly of a plastics moulded article mounted for rotation on a spindle,the plastics moulded article having a bore which is closed at one end, an annular rib in the wail oftheboreadjacentthe closed end and at least one gap in the ribto allowthe passage offluid past the rib, and the spindle having a circumferential groove adjacent each end of the spindle, characterised in that the grooves are similar and equi-distantly spaced from the ends ofthe spindle whereby either end of the spindle can be inserted into the bore and forced past the rib so thatthe rib locates in one of the grooves to retain the spindle in the bore, the other groove being adapted to receive a fastening memberto attach the spindle to an article offurniture.

2. An assembly of a plastics moulded article and a spindle as claimed in claim 1 mounted on an article offurniture, one end ofthe spindle being iocated in the bore with the rib located in one of the grooves on the spindle to retain the spindle in the bore and the other end of the spindle being attached to the article offurniture with the aid of a fastening member mounted in the other groove on the spindle.

3. An assembly of a plastics moulded article mounted for rotation on a spindle substantially as described herein with reference to the accompanying drawings.