GB2263449A - Wheel with double-bolt brackets for variable-gauge vehicles - Google Patents

Abstract

A wheel (10) for variable-gauge vehicles comprises an annular rim (11) for reception of the tire and a central plate (15) of generally polygonal shape fixed to the inner part of the rim by means of double bolting of bracket corners (12) welded to the rim. Each bracket (12) is made up of a generally rectangular plate in the shape of a double omega to identify in the central loop of each omega a reception seat for one of two bolts (13, 14) for fastening of the central plate (15). The free ends and the central pan between the omegas are welded below to the rim (11) and between the outside of the omegas and areas welded to the rim are drawn ribbings for strengthening. <IMAGE>

Description

"Wheel with double-bolt brackets for variable-gauge vehicles" In the art of construction of wheels for motor vehicles particular embodiments called 'variable gauge' are known.

Said embodiments comprise an annular rim bearing the tire and to which is bolted a central plate for constraint to the hub. The central plate and fastenings between the plate and the rim are realised in such a manner that by reversal of the mutual directions of the rim and plate and between the plate and hub it is possible to obtain greater or smaller projections of the vehicle wheels. This is advantageous especially in agricultural machines where for stability of the vehicle there is required the broadest gauge possible compatible with the width of the paths to be covered such as for example traversing long cultivated rows or equivalent.

It is obvious that the fastening between the rim and plate is the most criticai part of the realisation. Indeed, the connection must be easy to remove to allow rapid change of gauge but must also be safe and not give a source of weakening of the wheel structure.

Usually the attachment between the plate and the rim is made with brackets welded internally to the rim and bearing seats for bolts passing through holes in the plate. To supply greater strength and safety in case of sudden failing of a bolt, there are known fasteners termed 'double bolt' in which the plate is fixed to each bracket through a couple of paired bolts.

An example of this type of fastener is described in patent BG 2 058 686 where there are shown plate brackets welded to the rim and having an extension in the plane of the rim. Said brackets have however limited strength, the welding 'surface offered thereby being small and easily twisted by transverse loads such as those produced by shocks on the corner of the rim.

Another example of fastening with double bolts is shown in patent GB 2 167 717 where a continuous bracket extends circularly along the entire rim. This realisation is however costly given the waste of material involved while continuing to have the shortcomings mentioned above of a small welding corner and easy lateral deformability.

The general purpose of the present invention is to overcome the above mentioned shortcomings by supplying a wheel of the variable gauge type with double bolt fastening which would have strong fastening brackets with substantially no possibility of lateral deformability and with high welding surface with the rim.

In view of said purpose it was sought to provide in accordance with the present invention a wheel for variable gauge vehicles comprising an annular rim for reception of the tire and a central plate of generally polygonal form fixed to the inner part of the rim by means of double bolting of the corners to brackets welded to the rim and characterized in that each bracket is made up of a generally rectangular plate in the form of a double omega to identify in the central loop of each omega a seat for reception of one of two bolts for fastening of the central plate, the free ends and the central part between the omegas being welded below to the rim and between outer parts of the loops of each omega and areas welded to the rim there being moulded strengthening ribbings.

To clarify the explanation of the innovative principles of the present invention and its advantages compared with the known art there is described below with the aid of the annexed drawings a possible embodiment by way of non limiting example applying said principles. In the drawings - FIG. 1 shows a front view of a wheel made in accordance with the present invention, - FIG. 2 shows a partial cross section view along plane of cut II-II of FIG. 1, - FIG. 3 shows a view of a bracket of the wheel of FIG. 1 before its bending, - FIG. 4 is a side view of a bracket of the wheel of FIG.

1 made by bending of the plate shown in FIG. 3, - FIG. 5 is a bottom view of the bracket of FIG. 4, - FIG. 6 is a cross section view along plane of cut VI-VI of FIG. 4, and - FIG. 7 is a cross section view along plane of cut VII-VII of FIG. 4.

With reference to the figures FIG. 1 shows a wheel indicated generally by reference number 10 comprising a rim 11 inside which are welded brackets 12 for fastening with double bolts 13 and 14 of a central plate 15 for connection of the wheel to the hub (not shown) in accordance with conventional methods. As may be seen in FIG. 1 the plate has a generally polygonal shape, e.g.

square, and is fixed by a bracket at each corner. Said corners can be advantageously bevelled to adapt them to the inner curvature of the rim.

FIG. 2 shows in greater detail the fastening between the rim, bracket and plate. In accordance with the known art the drawing of the central plate 15 and the asymmetrical position of the flange with respect to the median plane of the rim allow change of the vehicle gauge by merely reversing the mutual direction of the rim and plate and combining it with the positioning of the plate to the right or left of the brackets (as seen in FIG. 2).

In accordance with the present invention as shown in FIG.

3 each bracket 12 is made from a generally rectangular metallic plate 16 which is bent at the lines 17 and 18 to form it like a double omega as shown in FIG. 4 where are visible also strengthening ribbings 21, 22 and 23, 24 arranged at the sides of each omega 19, 20 respectively so as to form a triangular trend along the extension of the bracket. Said ribbings have a rounded base form as shown in FIG. 5 and in FIGS. 6 and 7. The bracket is also curved inward to adapt to the inner curvature of the rim.

Each omega 19, 20 identifies with its central loop a central passage 25, 26 for housing of one of the two double fastening bolts 13, 14 Drawings 27 project toward the inside of the omegas near the base of the loop so as to delimit at the bottom the bolt seat. As shown in FIG. 3 said drawings can be advantageously executed on the plate 16 which forms the bracket before its curvature in a double omega.

During bending of the plate 16 to form the double omega it is unavoidable to create folds at its side corners near the omega loops. To prevent said folds from constituting invitation to breakage the side corners of the omega are coined after forming as shown with reference 28 of FIGS. 4 and 5.

The brackets thus provided are welded in position inside the rim opposite their areas of adherence thereto represented by the free ends and by the central part between the omegas. Given the broad contact surface of each bracket the welding is extensive and therefore reliable. In addition, the extended of the bracket axially to the rim supplies excellent holding against possible distortions under load.

At this point it is clear that the purposes set of supplying a wheel with anchoring brackets of the double bolt type which, being economical to manufacture, ensure high strength, are met.

Naturally the above description of an embodiment applying the innovative principles of the present invention is given merely by way of example and therefore is not to be taken as a limitation of the patent right claimed here For example, the conformation of the rim and central plate can be different from that shown to adapt it to peculiar requirements. For this reason the number of brackets and thus the number of corners of the central plate 15 can be changed.

For the avoidance of doubt the term "omega'' is intended to cover both fl and. shapes.

Claims (6)

1. Wheel for variable-gauge vehicles comprising an annular rim for reception of the tire and a central plate of generally polygonal form fixed to the inner part of the rim by means of double bolting of the corners to brackets welded to the rim and characterized in that each bracket is made up of a generally rectangular plate in the form of a double omega to identify in the central loop of each omega a seat for reception of one of two bolts for fastening of the central plate, the free ends and the central part between the omegas being welded below to the rim and between outer parts of the loops of each omega and areas welded to the rim there being moulded strengthening ribbings.

2. Wheel in accordance with claim 1 characterized in that each bolt reception seat is delimited at the base of the respective loop by drawings pressed into the walls of the omega and directed toward each other.

3. Wheel in accordance with claim 1 characterized in that the strengthening ribbings form on each omega a triangular profile.

4. Wheel in accordance with claim 1 characterized in that the corners of the central plate are cut off to adapt them to the inner conformation of the rim near the respective bracket.

5. Wheel in accordance with claim 1 characterized in that the central plate has a substantially square shape.

6. Wheel in accordance with claim 1 characterized in that opposite the omegas the side parts of the bracket are coined.