FR2757104A1 - Vehicle wheel with integral tyre pressure gauge - Google Patents

Abstract

The vehicle wheel inflation monitor consists of a pressure gauge situated coaxially in the centre of the wheel and equipped with a mark or symbol corresponding to normal pressure, with a tube (2) connecting the pressure gauge to the tyre. The tube is made from a copper alloy and is equipped at one end with a screw or rivet to receive the pressure from the tyre via a hole which may be threaded. The screw or rivet is brazed to the tube and is of copper or a copper alloy, while the tube is in two separate portions and joined end-to-end by a copper alloy sleeve stuck or brazed in place. The copper alloy connecting tube is attached to a valve fixed to the wheel rim and comprising a main body (1) fitted into a circular seal in the rim's valve aperture. The wheel rim also has a bush (3) of copper or zinc alloy or of brass, to which the tube is brazed, and which fits round the valve body and compresses its seal.

Description

The subject of the present invention is a vehicle wheel inflation control device, composed of a rim, an inflatable tire and a tire inflation valve.

comprising a pressure gauge comprising at least one mark or symbol such as a colored sector corresponding to a normal inflation pressure (or pressure range) of the tire, characterized in that said pressure gauge is disposed eccentrically, with reference to the axis of rotation of the wheel, and is preferably fixed to the rim near the periphery thereof by means of a connecting piece, removable or coming from foundry.

It also relates to a vehicle tire inflation control device, composed of a rim, an inflatable tire and a tire inflation valve, comprising a pressure gauge comprising at least one reference or symbol such as a colored sector corresponding to a normal inflation pressure (or pressure range) of the tire, characterized in that said pressure gauge is disposed eccentric, with reference to the axis of rotation of the wheel, and is preferably fixed to the rim at proximity of the periphery thereof by means of a connecting piece making it possible to orient and then block the manometric system around its axis of symmetry.

The present invention aims to improve that described in European patent No. 72,768, issued August 14, 1982.

The search for a reduction in production costs leads to the provision of a manometric system, no longer placed at the center of a wheel, but at its periphery. This avoids the connection tube, the pressure tapping on the rim and the fixing of the pressure gauge by ring or rods, which were necessary since the housing was in an area normally occupied by the wheel hub.

To obtain this result, it is necessary to provide a fixing lug (6), shown in gray on board 1/3, coming from the foundry, which is pierced with a channel (7), connecting the interior of the tubeless tire with a threaded hole into which the pressure gauge connection (3) is screwed.

 It is therefore held on the wheel, while being permanently pressurized, the seal being ensured by a seal (4).

The dimensions of this lug (6) must allow the pressure gauge (3) to enter the rim gauge (2), this in order to avoid curbs.

Similarly, the rear part of this lug (6) must also avoid the calipers (5) of the disc brakes.

We can see, on sheet 1/3, that it is possible to meet these requirements with a structure corresponding to a commercial alloy rim, this in the context of mass production.

According to FIG. 3, constituting a partial view from the left, and in order to compensate for the action of the centrifugal force on the end of the drone tube (9), the pressure gauge is screwed in such a way that the radial force (10) acts in the direction of decreasing pressures, or by bringing its end towards the center of the pressure gauge.

Under these conditions, the action of the centrifugal force, of the order of 1.5 kgf at 200 km / h, is deducted from that generated by the pressure exerted in the tire, which on the contrary tends to move away the end of the drone tube from the center of the pressure gauge.

If this were not so, the elastic limit of the Bourdon tube (9) could be exceeded, introducing at the stop a drift of the indications provided by the system needle.

The pressure gauge housing is thus immobilized in this position by means of two needle screws (8) (see FIG. 1 representing a partial view from the right).

As a variant, note the possible use of membrane manometers, eliminating this subjection since the sensors are geometrically different, the disks of which they are made being sensitive, as external forces, only to gyroscopic effects if their planes are parallel to the wheel rotation plane.

But they are only manufactured from 50mm diameter cases.

Figure 4 shows the device as seen by the user.

This lug (6), provided coming from foundry, can just as easily be an independent part of the rim, This variant is interesting to consider for steel rims which would not support a sufficient deformation, coming from forge, to constitute a lug .

According to FIG. 5, concerning a commercial steel rim, there is thus the lug (6) into which the connection of the pressure gauge (3) is screwed, the sealing being carried out by a seal (4).

The orientation of the pressure gauge (3) operates as above by mechanical locking, for example by means of needle screws (not shown on the board 3/3).

On the other hand this lug (6) is held on the rim (14) by means of a screw (11) locked by a fan washer (12). A seal (13) seals between (6) and the rim (14).

The pressure travels through this fan washer (12), follows the threads of the screw (11), passes through the lug (6) thanks to the transfer channel (7), and finally ends at the rear of the threaded connection of the pressure gauge (3).

A rubber or plastic cap covers the head of the screw (11) in order to prevent the tire bead from being damaged when the casing is mounted on the rim (not shown in FIG. 5).

The retention of the lug (6) on the rim (14) can also take place by riveting, by welding or any other means.

The rim web is notched at (15) to allow the installation of the pressure gauge (3), this notch having to be produced in series during the manufacture of the rim web.

The imbalance on the rim, caused by the presence of the device, is of the order of 100 grams.

 It therefore enters into the balancing possibilities of machines which accept at least 150 grams.

Note that it is possible, in the case of alloy rims, to provide an extra thickness of the metal, located opposite the system, in order to economically balance the wheels.

These provisions can also apply to motorcycles and heavy goods vehicles.

Claims (2)

 1) -Vehicle wheel inflation control device, composed of a rim, an inflatable tire and a tire inflation valve, comprising a pressure gauge comprising at least one mark or symbol such as a colored sector corresponding to a normal inflation pressure (or pressure range) of the tire, characterized in that said pressure gauge is disposed eccentrically, with reference to the axis of rotation of the wheel, and is fixed to the rim near the periphery of this by means of a connecting piece, removable or coming from the foundry. 2) -Vehicle tire inflation control device, composed of a rim, an inflatable tire and a tire inflation valve, comprising a pressure gauge comprising at least one mark or symbol such as a colored sector corresponding to a normal inflation pressure (or pressure range) of the tire, characterized in that said pressure gauge is disposed eccentrically, with reference to the axis of rotation of the wheel, and is fixed to the rim near the periphery of this by means of a connecting piece making it possible to orient and then block the manometric system around its axis of symmetry.