NZ203215A - Guard bar for use while inflating tyres on split-rim wheels - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £03215 203215 N.Z. PATENT QFyfef 2 1 JAN 1986 ReOEfVEO Patents Form No.5.

Patents Act 1953 COMPLETE SPECIFICATION No. 203215 Date: 8th February, 1983 " -rfRe ^Safety Device" I, ALFRED BERTRAM CARPENTER, a New Zealand citizen, of 11 Somerfield Street, Christchurch 2, New Zealand, hereby declare the invention, for which I pray that a patent may be granted to me and the method by which it is to be performed, to be particularly described in and by the following statement • 203215 .L M "TV'fce. IWFI-ATIO*/ <&jU The present invention relates to aiisafety device for i«r H J J J ft use when changing a tyre on a vehicle wheel of a type which has a split rim.

Generally, a split rim comprises a wheel centre, a locking ring and a retaining ring. The wheel centre forms the major part of the wheel and is formed with holes to receive the wheel-studs. The locking ring is formed to P engage a shoulder on the wheel centre and lies between the wheel centre and the retaining ring which contacts one edge of the tyre. When the tyre is fully inflated on the rim, the locking and retaining rings are held tightly in place. However, while the tyre is being inflated, the locking and retaining rings sometimes slip, or are knocked, out of alignment, and if this happens, the pressure of the air in the tyre is sufficient to push the rings and the tyre off the wheel centre, often with explosive force. Split-rim wheels are notoriously dangerous in this respect, and have caused many fatal accidents. Most countries require tyres on split rims to be reinflated in a safety-cage, to contain the 'explosion' if the rings have been misaligned, but such cages are inconvenient and time-consuming to use, and so all too often are not used.

A number of different designs of split rims are known, but the device of the present invention may be used with various designs of split rim, since the operation of the device does not depend upon the rim. design. The device of the present invention may be used with any size of wheel; however, wheels with rims smaller than 16 inches generally are one-piece rims rather than split rims, andvheels with rims greater than 25 inches generally have a split rim which incorporates locking 203215 tabs and so is much safer than the split rims generally used on smaller wheels.

An object of the present invention is the provision of a safety device which is portable and quick and easy to use, but which will prevent a tyre being reinflated slipping off a split rim even if the retaining and locking rings are misaligned.

The present invention provides I A tyre inflation safety device for use with split-rim wheels, said device comprising: a bar and means for securing said bar to a wheel centre such that in use said bar will overhang said split rim at at least one point on the circumference of said rim, said bar being formed with a slot along the length thereof but not extending to either end of the bar, and said device including a first arm siidably' engaged in the slot, said first arm providing a first limb which extends through the slot and a second limb substantially perpendicular to the first limb, said first arm being suspendable from the bar such that said second limb is spaced from the bar by a first predetermined distance, arid a spacer engageable with the arm and bar to secure said arm in a fixed position relative to the bar.

Preferably the bar is formed with a slot along the length thereof but not extending to either end of the bar, and the device may include a pair of arms slidably engaged in the slot, each said arm providing a first limb which extends through the slot and a second limb substantially perpendicular to the first limb, each said arm being suspendable from the bar such that said second limb thereof is spaced from the bar 203215 by a first predetermined distance; and a spacer insertable between said arms to space the arms apart by a second predetermined distance.

By way of example only, a preferred embodiment of the present invention is described in detail with reference to the drawings accompanying the provisional specification in which Fig.l is an oblique perspective view of the device of the present invention; and Fig.2 is a section through the device of Fig.l in use.

Referring to the drawings, a safety device 2 comprises a bar 3, a pair of arms 4, and a spacer 5. The bar 3 is made of U-cross-section steel channel and a slot 6 is formed through the top surface 3a of the channel, parallel to the length of the bar and stopping short of each end of the bar.

Each arm 4 is L-shaped: the longer limb 7 extends 6 through the slot/in the bar 3 and the shorter limb 8 is spaced a distance 'a' above the surface 3a of the bar, by a peg 9 and a flange 10, which are located respectively above and below the surface 3a, and are secured to the limb 7. The distance 'a' is slightly greater than the thickness of the top surface 3a of the bar plus the thickness of a wheel centre with which the device is to be used, so that the inner edge of the wheel centre will slide freely between the bar and the limbs 8 of the arms.

The arms 4 are arranged in the slot 6 with the shorter limbs 8 pointing away from each other, and are free to slide, along the slot.

The spacer 5 comprises three integrally-formed portions, 203215 11,12,13 each having a width 'b' slightly less than that of the slot 6, but differing in length. The longest portion 13 has an apertured centre so that the spacer also can serve as a handle. A block 14 is formed on each side of the spacer, between the portions 12 and 13, to provide a portion of greater width than the slot.

The above-described device is used as follows:- a wheel 16 to which a tyre is to be refitted has the deflated tyre 17 fitted to the wheel centre 18 and the locking ring 19 and the retaining ring 20 located in known manner, as shown in Fig.2. The wheel and tyre then are placed on a suitable flat supporting surface (such as the ground), with the locking and retaining rings uppermost, and the safety device 2 is placed on top, with the top surface 3a of the bar 3 contacting the wheel 16, and the ends of the bar 3 equidistantly spaced from the running surface of the tyre. ~ The arms 4 are slid together in the centre of the slot 6, to allow the shorter limbs 8 to pass through the central hole of the wheel centre 18, and the arms 4 are then slid away from each other in the slot 6 until the upper surface of each limb 8 engages the underside of the wheel centre 18 and each limb 7 engages the edge of the central hole, in the manner shown in Fig.2. The arms 4 are then locked in this position by the spacer 5, which is lowered between the arms 4 until one of the three portions 11, 12, 13, contacts the arm54. The central holes of most wheel centres are made in one of three standard sizes, and the portions 11,12,13, are sized accordingly. With the spacer 5 between the arms 4, the device is securely locked onto the wheel. 203215 The tyre is now reinflated in the usual way. If, during reinflation, the locking and retaining rings appear to be moving out of alignment, they can be tapped back into place with a mallet, because the operator has access to the rings, except for the small portions covered by the bar 3.

If the rings start to come off the rim, the ends of the bar 3, which extend over the rings at two diametrically opposed points, prevent the rings from moving more than about 1-1/2 inches from the rim, and so prevents the rings from flying off the rim. If the ends of the bar 3 also overhang the tyre 17, as shown in Fig.2, then the bar 3 also prevents the tyre from moving more than about 1 inch away from the rim, and this acts as an additional safety precaution. However, the safety device will operate satisfactorily providing the bar is long enough to overhang the retaining and locking rings at at least one point around their circumference (e.g. bar could be cut short) and/or could be positioned assymme-tricolly on the wheel. The device may also be used with only one arm 4, e.g. if the wheel is a non-standard size.

In this case, the single arm 4 is engaged with the wheel centre 18 as described above, and is secured in position by jamming the spacer between said arm and the edge of the wheel centre.

When the tyre is fully reinflated, the device is removed by removing the spacer 5, and sliding the arms 4 together to disengage them from the wheel centre. When removed, the device, may be carried by passing the portion 13 of the spacer through the slot 6, until the blocks 14 contact the underside of the top surface 3a of the bar. The portion 13 then forms a handle for the device.

Claims (5)

203215 Each arm 4 may be formed with two or more parallel shorter limbs 8, spaced so as to accommodate different sizes of wheels. It will be appreciated that the above-described device may be made in any size or range of sizes, of any suitably robust material. - 7 - 203215 WHAT I CLAIM IS:

1. A tyre inflation safety device for use with split-rim wheels, said device comprising: a bar and means for securing said bar to a wheel centre such that in use said bar will overhang said split rim at at least one point on the circumference of said rim, said bar being formed with a slot along the length thereof but not extending to either end of the bar, and said device including a first arm slid-ably engaged in the slot, said first arm providing a first limb which extends through the slot and a second limb substantially perpendicular to the first limb, said first arm being suspendable from-the bar such that said second limb is spaced from the bar by a first predetermined distance, and a spacer engageable with the arm and bar to secure said arm in a fixed position relative to the bar.

2. A tyre inflation safety device according to Claim 1 further comprising a second arm slidably engaged in the slot, said second arm providing a first limb which extends •through the slot and a second limb substantially perpendicular to the first limb, said second arm being suspendable from the bar such that said second limb thereof is spaced from the bar by a first predetermined distance, and a spacer insertable between said first and second arms to space the arms /apart by a second predetermined distance.

3. A tyre inflation safety device as claimed in Claim 1 or Claim 2 wherein the or each said arm is formed with two °r more spaced, mutually parallel, second limbs. - 8 - 203215

4. A tyre inflation safety device as claimed in Claim 2 in which said second predetermined distance is determined by the width of the spacer, and said spacer provides a Plurality of portions each of different width.

5. A tyre inflation safety device for use with split-rim wheels, substantially as hereinbefore described with reference to and as shown in the drawings accompanying the provisional specification. Alfred Bertram carpenter by his authorised agents P.L. BERRY & ASSOCIATES per: ' ' VLAND 12DEC1986 PATEC4T OFFICE - 9 -