Tire for a handling vehicle

Abstract

A tire for a handling vehicle, designed to transport heavy loads, over short distances and at low speeds, and a mounted assembly consisting of a tire mounted on a rim. Also, a method for producing such a mounted assembly. A mounted assembly includes a tire mounted on a rim, having a tread designed to come into contact with a ground, two sidewalls extending radially inwards from the ends of the tread, and two beads extending the sidewalls radially inwards and in contact with the rim, an internal cavity containing a filling component consisting of at least one incompressible solid element, and which is a granular filling component consisting of granules at least partly separated from one another by interstices containing at least gas, and the fill rate, which is the ratio between the total volume of the granules, the total of the elementary volumes of the granules, and the volume of the internal cavity, is at least equal to 0.8.

Claims

1. A method for producing a mounted assembly, the mounted assembly comprising: a tire mounted on a rim, the tire comprising a tread designed to come into contact with a ground, two sidewalls extending radially inwards from the ends of the tread, and two beads extending the sidewalls radially inwards and in contact with the rim, the tread, the two sidewalls, the two beads and the rim delimiting an internal cavity, the internal cavity containing a filling component comprising at least one incompressible solid element, wherein the filling component is a granular filling component consisting of granules at least partly separated from one another by interstices containing at least one gas, the fill rate, which is the ratio between the total volume of the granules, the total of the elementary volumes of the granules, and the volume of the internal cavity, is at least equal to 0.8, and the method comprises the following steps: a) installing a cylindrical shroud with a diameter equal to the diameter of the rim, so as to close off the internal cavity of the tire, filling the internal cavity of the tire with the granular filling component with the aid of a filling means, and compacting the granules, so as to obtain the intended fill rate and to form an intermediate assembly comprising the tire, filled with the granular filling component, and the shroud; b) installing the intermediate assembly on a transfer frame comprising a transfer means and the rim onto which the tire, filled with the granular filling component, is to be mounted; and c) transferring the tire, filled with the granular filling component, from the shroud onto the rim, by application of a force parallel to the axis of revolution of the tire by the transfer means, so as to form the mounted assembly.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The features of the invention will be better understood with the aid of the description of the appended FIGS. 1 to 3C:

(2) FIG. 1A shows a view in section in a meridian plane of a mounted assembly consisting of a tire, of which the internal cavity is filled with a granular filling component, mounted on a rim.

(3) FIG. 1B shows an enlarged view of the granular filling component.

(4) FIG. 2 shows curves of the change in load as a function of the flexing of a tire.

(5) FIGS. 3A to 3C show the steps of producing a mounted assembly according to the invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

(6) FIGS. 1A to 3C are not shown to scale in order to make them easier to understand.

(7) FIG. 1A shows a meridian section of a tire 1, along a plane passing through the axis of revolution of the tire, mounted on a rim 5. The tire 1 comprises a tread 2 designed to come into contact with a ground, two sidewalls 3 extending radially inwards from the ends of the tread 2, and two beads 4 extending the sidewalls 3 radially inwards and in contact with the rim 5. The tread 2, the two sidewalls 3, the two beads 4 and the rim 5 delimit an internal cavity 6. The internal cavity 6 contains a granular filling component 7 consisting of granules.

(8) FIG. 1B is an enlarged view of the granular filling component. The granules 71 are separated by interstices 72 containing at least one gas.

(9) FIG. 2 shows three curves C.sub.1, C.sub.2 and C.sub.3 of change in the load Z applied to a tire as a function of the flexing f of the tire. The slope of the straight line tangential to a curve C, at a point (Z, f), defines the vertical rigidity of the tire at this point. The curve C.sub.1 shows the change in the load Z as a function of the flexing f for a tire, with no granular filling component and inflated to a pressure P. The curve C.sub.2 shows the change in the load Z as a function of the flexing f for a tire, with a granular filling component but not inflated. The curve C.sub.3 represents the change in the load Z as a function of the flexing f for a tire, with a granular filling component and inflated to the same pressure P as that of the curve C.sub.1. The curve C.sub.3 is indistinguishable from the curve C.sub.1, characteristic of a conventional inflated tire, for load values below a transition value, then, after a transition zone, is indistinguishable from the curve C.sub.2, characteristic of a solid tire.

(10) FIGS. 3A to 3C show schematically the steps of the method for producing a mounted assembly according to the invention.

(11) FIG. 3A shows the first step of the method. A cylindrical shroud 8 with a diameter equal to the diameter of the rim is put in place so as to close off the internal cavity 6 of the tire 1. The filling of the internal cavity 6 of the tire 1, closed off by the cylindrical shroud 8, is then carried out with the granular filling component 7 with the aid of a filling means 9 passing through the cylindrical shroud 8. The granules are compacted with the aid of an appropriate means (not shown) so as to obtain the intended fill rate. The result of the second step is the formation of an intermediate assembly 1, 7, 8.

(12) FIG. 3B illustrates the second step of the method which consists in placing the intermediate assembly 1, 7, 8 on a transfer frame comprising a transfer means 10 and the rim 5 on which the tire 1 is to be mounted.

(13) Finally, FIG. 3C illustrates the third step of the method which is the transfer of the tire 1, filled with the granular filling component 7, from the shroud 8 to the rim 5, by the application of a force parallel to the axis of revolution of the tire by the transfer means 10 so as to form the mounted assembly 1, 7, 5.

(14) The inventors have produced a mounted assembly according to the invention for use on a handling vehicle and according to the filling method described. The granular filling component used consists of granules of retreading powder originating from the recycling of treads during the retreading of tires. The interstices between the powder granules are filled with atmospheric air. The fill rate obtained is equal to approximately 0.85. Tests have also been carried out according to the various embodiments described: with inflation air at the pressure of use of the tire, with a liquid such as water, and with a carbon black-based powder.