GB2038727A - Wheel rim - Google Patents

Abstract

A well obstructor for a wheel rim has two band parts 2, 3 articulated together by claws 12, 14. The claw 12 originates from a minor portion 10 of the circumferential length of the band which is (in use) situated radially below the mouth of a well of a wheel rim. This allows the band to be used to prevent the escape from a rim of either a tubed or a tubeless tyre (the valve of the inner tube of a tubed tyre gaining access to a valve aperture in the rim in the region of the minor portion 10). The other end of the portion 10 is formed by a sloping wall 9 reinforced by a gusset 16 extending between it and a transverse positioning lug 8. <IMAGE>

Description

SPECIFICATION Wheel rim This invention relates to a wheel rim and a wellobstructor for it, which offers the facility of preventing the escape of the tyre from the wheel rim to which the obstructor element is fitted and which is suitable for use with either a tubed or a tubeless tyre.

In U.K. Patent 1420622 and its Patent of Addition No.1488871 the general aim of such obstructorswas discussed and there were shown constructions of obstructor which were intended for use with tubeless tyres only.

In co-pending but unpublished U.K. Patent Application No. 39369176 there is proposed a band-like obstructorelementwherein a minor portion of the periphery of the band is cranked inwardly to be inset from the major part of the band, which lies at or about the mouth of the well and prevents ingress of a tyre into any part of the well. The cranked portion is proposed as being at the middle of the length of the band, or of parts of the band, being limited by inclined side walls running radially inwardly from the portion lying at the mouth of the well to the minor portion which overlies the base of the well.

This minor inset portion allows access to an aperture in the well in which the valve of a tubed or of a tubeless tyre could be fitted.

The present invention develops this type of obstructor used with a tubed or with a tubeless tyre and is concerned with the design of that obstructor element and with a rim fitted with it which is economical, better balanced, stronger and generally more convenient than that proposed in said copending application.

In the present invention an obstructor band is provided, and a wheel rim can be fitted with such a band, in which the utmost economy of material is achieved in providing all the advantages of a positively retained and inextensible multi-part band in a wheel rim; in that the minor radially inset portion is used as the origin of an articulation member linking two parts of the multi-part band.

Furthermore if preferred retention means are used, tightening, loosening or general assembly of the band is considerably eased due to the ability of the retention means readily to adjust its relationship to the exactly tangential direction of the rim.

In the present invention an inextensible, usually metal, obstructor band is made up of a plurality of parts, preferably two, and the parts are articulated together at all except a first pair of adjacent ends. At the first pair of adjacent ends there are provided means for holding those ends together under tangential tension in the rim whereby to hold the complete band inextensibly, positively and under tension in the rim.At at least one pair of articulated adjacent ends of the multi-part band there is provided an articulation means comprising a radially inwardly directed hook element on one of the adjacent ends and a radially outwardly directed hook element on the other of the adjacent ends, the other of the adjacent ends comprising a radially inset minor portion of the total periphery of the band and the radially outwardly directed hook originating from that radially inset minor portion. The other end of the inset minor portion of the band is constituted by a radially inwardly inclined wall and the remainder of the periphnery of the band with which the said wall adjoins, is an obstructor portion adapted to lie at the mouth of the well and prevent ingress into the well of any tyre mounted on a rim to which the band is fitted.

Preferably, axially directed lugs are provided on an inner surface of the band (analogous to and for the same purpose as those in U. K. Patent No.1488871) an endmost one of these lugs being used as an anchor point for a gusset which reinforces the inclined wall of the minor inset portion and holds it against extending distortion when the band is under tension.

In a particularly advantageous embodiment of the invention the means for holding the first pair of adjacent ends together includes a tagentially directed screw member bearing on a claw at one of the said adjacent ends and screwthreadedly engaged in a diametrical bore in a cylindrical member arranged with its axis parallel to the axis of generation of the band (the axis of rotation of the rim into which the obstructor band is fitted) and pivotally movable about its own axis. The retention of the cylindrical element may be by means of a recurved inturned end claw, curved back around the cylindrical member or by a retainer wire secured to the end claw and to the cylindrical part of the band and running in grooves to entrap the cylindrical element.

The lugs need not be axially centrally disposed on the band, but may be offset.

An embodiment of the obstructor element and of a rim incorporating it will now be described with reference to the accompanying drawings wherein: Figure 1 is a side view of the band-like obstructor element, Figure 2 is a perspective detail view of the inset cranked portion and engaged clasps, Figure 3 is a detail view of the engaged clasps as seen from within the band, Figure 4 is a view looking in the direction of the arrow A in Figure 1, Figures 5A and 5B are views of the bolt receiving lugs of the two portions of the band-like element, Figure 6 is a side view of the tightening bolt, and Figure 7 is a perspective view of the floating nut for that bolt.

Referring to the drawings, the band-like obstructor element 1 for a one-piece wheel rim is formed of two similar metal portions 2,3. These are articulated together at a first air of adjacent ends 4 and at the other of their adjacent ends 5 are secured together by a tangentially directed tightening screw 6.

Welded to the inner surface of each portion 2,3 are four radially inwardly extending, axially directed lugs 8 in which, when the band is assembled onto a wheel rim, rest on the base of that rim and/or abut against one or both of the side walls of the wall, as discussed and disclosed in U.K. Patent 1488871.

At a second pair of adjacent ends the band portion 3 is provided with an inset portion 7 namely a part of the band which is inwardly cranked, and which occupies a minor proportion of the periphery of the band-like obstructor as a whole and therefore ofthe rim. The major portion of the obstructor element are part-cylindrical portions which when fitted in a rim lie at the mouth of the well (either in the mouth or slightly above it) to prevent ingress of a tyre band into the well. As seen in more detail in Figure 2, the inset portion is connected to the main part of the band 3 by means of a sloping end wall 9 and is thereafter continued by a floor portion 10. The end of the floor portion 10 is returned outwardly to form a hook claw 12. The end 4' of the other band portion 2 is also returned to form an inwardly directed claw 14.

The claws 12, 14 can be hooked together and allow the band portions 2,3 to hinge relative to each other about the point of contact of the two claws.

The floor portion 10 is narrower than the remainder of the band since the side walls of the well in which it is to fit will normally taper as they go radially inwardly. Accordingly, the end wall 9 tapers to conform to the side walls of the well and likewise the returned claw 14 tapers inwardly towards its extremity. The claw 12 does not taper but has the same width as the floor portion 10. The lugs 8 may be centered about the centre line of the width of the band, or offset partly to one side of that centre line; if they are offset the floor portion will be similarly offset.

The end wall 9, the floor portion 10 and the claw 12 are formed integrally with the band portion 2 by bending of the steel strip material from which it is made. The sloping end wall 9 is reinforced by a gusset 16 welded between it and the adjoining endmost one of the lugs 8. The claw 14 is formed by bending of the strip material of the band portion 2.

As mentioned, the inset portion occupies only a minor proportion of the periphery of the band-like obstructor as a whole and it is suggested that its maximum tangential length, as indicated in Figure 1 by the double-headed arrow 18, may be about 10 cm for a rim of 180 cm periphery. The precise proportions will of course depend on the characteristics of the wheel to be fitted with the obstructor.

At the other ends 5 of the band portions 2,3 each terminates in a radially inturned lug 20, 22 respectively. These taper to be free of the side walls of the well which the portions 2, 3 are to fit. They are secured together by a bolt 24 passed through a hole 28 in the lug 22, through a slot 30 in the opposed lug 20 and then engaged in a cylindrical nut 34. A slot 36 is provided in the band portion 3 to permit insertion of the bolt 26 and a tool to tighten the bolt. The arc over which slot 36 extends is indicated in Figure 1 by the double-headed arrow 38.

As best seen from Figure 7, the nut 34 is generally cylindrical with a transverse bore 40 to receive the bolt 26. Spaced inwardly from each end of the cylinder is circumferential groove 42 and the bolt is held loosely in place on the band portion 2 by wires 43 which are engaged in these grooves and welded to the band portion 2. These wires hold the nut sufficiently firmly in place to allow insertion of the bolt 26 but permit the nut to roll on the surface of the lug 20 as the bolt is tightened, thereby avoiding any tendency for the bolt to bend as it is tightened and the obstructor element settles into the well. As best seen from Figure 6, the bolt 26 is threaded for only a part 44 of its shank, and has a short threaded tip section 46 which has the same diameter as the base of the thread. This unthreaded tip facilitates entry of the bolt 26 into the nut 34 on assembly. The unthreaded section 48 adjoining the head of the bolt 26 ensures that the bolt cannot be tightened too far, and that a minimum spacing is maintained between the opposed lugs 20. 22.

The method of assembling this band-like obstructor onto a wheel rim is clear from the foregoing.

A tyre on the rim has both beads brought to be clear of one side of the well. The portions 2, 3 are articulated together, closed round the rim and the bolt 26 tightened. One of the beads is then allowed to spring back past the well. An arrow 50 is stamped onto the floor portion 10 at the point which should be positioned opposite the valve aperture in the wheel rim. If the tubed tyre is used a cord may be passed through the valve aperture and the valve of the innertube and the latter may be drawn into its aperture in the rim by traction on the cord.

Claims (8)

CLAIMS:

1. A wheel rim having a circumferentially continuous well between its bead seats and an inextensible obstructor band for the well to be retained inextensibly in the well to prevent ingress of a tyre bead into any substantial part of the length of the well, the band including at least two parts articulated together and having a major portion of the circumference of the band to be substantially at the mouth of the well for preventing such ingress and a minor portion to be depressed radially below the mouth, the minor portion being adjacent the articulation of the band and being the origin of an articulation member which articules that band part which has the minor portion to an adjacent band part.

2. A wheel rim according to Claim 1 wherein the minor portion is bounded by an inwardly directed end wall at one end and by an outwardly directed hook-forming articulation member at the other.

3. Awheel rim according to Claim 2 wherein at least the first mentioned band part has laterally extending lugs for positioning the part radially and/or axially in the well.

4. A wheel rim according to Claim 3 wherein a gusset is secured to the end wall and to a lug next adjacent to the wall, to reinforce the end wall.

5. A wheel rim according to any one of the preceding claims wherein retaining means for drawing together adjacent ends of the band remote from the articulation include a tangentially directed screw acting between a radially inturned one of the adjacent ends and a nut engaging a radially inturned other of the adjacent ends, the nut being pivotable about its own axis.

6. A wheel rim according to Claim 5 wherein the nut is a cylindrical rod trapped rotatably behind its associated radially inturned end.

7. A wheel rim according to any one of the preceding claims substantially as herein described with reference to and as illustrated in the accom panying drawings.

8. An obstructor band as defined in any one of the preceding claims.