Patent Description:
The system is used to inform the driver of any abnormal variation in the measured parameter, for example the tyre pressure. Such systems typically include an inflation valve and an electronic module. The inflation valve is positioned in a bore or hole in the wheel rim and the electronic module is arranged inside the tyre and is coupled with the inflation valve.

One type of tyre parameter monitoring system or tyre pressure monitoring system (TPMS) is known as the snap-in type, in which the inflation valve, designed as a so-called snap-in valve, positioned on the outside of the wheel rim extends through a bore in the wheel rim and is connected to an electronic unit positioned on the inside of the wheel rim by a snap-in connection. Snap-in valves include an elastically deformable stem. An example of such a snap-in valve is disclosed in <CIT>.

Another type of tyre parameter monitoring system is known as the clamp-in type. For the clamp-in type it is possible to fasten the electronic module in various angular positions with respect to the wheel rim. This enables the system to be mounted on wheel rims of different designs. An example of such a clamp-in system is disclosed in <CIT>.

The document <CIT> discloses an electronic unit for measuring operating parameters of a vehicle wheel, wherein the fastening elements of an electronic unit and the inflation valve comprise an insert pivotally mounted in the extension of the body of the inflation valve.

The document <CIT> discloses a device for fastening a sensor on the inner side of a valve with respect to a wheel, the sensor being fixed to the valve by means of an adapter for arbitrary positioning and spacing of the sensor.

The document <CIT> discloses a connection structure for a sensor electronic module and an inflation valve, where a fixed first bevel and a second bevel for positioning, and a third bevel and a fourth bevel positioned so as to match to the first bevel and the second bevel are disclosed, and where the matching of the first bevel and the second bevel, and of the third bevel and the fourth bevel has the effect of stopping rotation and fixing the position, thus preventing rotation of the main body of the inflation valve relative to the electronic module.

The document <CIT> discloses a device for monitoring tire pressure, with an antenna for sending pressure data, a printed circuit board which carries a circuit for measuring and sending pressure data connected to the antenna, a power source arranged in the housing for supplying the circuit, and a housing surrounding the printed circuit board, where the housing is produced by overmolding the antenna.

Depending on various factors, a system of either the snap-in type or the clamp-in type may be desirable. In order to simplify assembly and reduce costs, it would be desirable to use components for both snap-in type and clamp-in type tyre parameter monitoring systems.

The invention is directed to a tyre parameter monitoring system as defined in claim <NUM>. The system comprises an electronic module with a fitting, a ball stud coupled to the fitting and a valve stem. The valve stem has a ball socket that is coupled to the ball stud to form a ball joint such that the valve stem is positionable at different angles to the electronic module.

The system may be considered to include an adapter which provides an articulated ball joint between the valve stem and the electronic module by the use of a ball socket in the valve stem and a ball stud that is coupled to the fitting. Thus, a clamp-in valve can be used with an electronic module having a fitting for a snap-in valve. The electronic module can, therefore, be used with both snap-in valves and clamp-in valves. The clamp-in valve is also positionable at different angles to the electronic module so that the system with a clamp-in valve can be used for wheel rims of differing designs which require differing angles between the valve stem and the electronic module. The tyre parameter monitoring system further comprises a nut, a washer and a seal. In use the position of the valve stem with respect to the electronic module may be fixed by securing the nut, the washer and the seal to a distal end of the valve stem and to a wheel rim. In the mounted position the nut is positioned on an outer surface of the wheel rim and is tightened to clamp the seal and washer between the valve stem and the wheel rim, to pull the valve stem inside the washer, exert pressure on the ball socket and block rotation of the valve stem around the ball head of the ball stud so as to provide an auto locking mechanism.

In an embodiment, the ball joint further comprises a connection stem extending from the ball stud and the connection stem is coupled to the fitting of the housing. The head of the ball joint, i.e. the ball stud, protrudes from the electronic module. In the mounted and assembled condition, the head of the ball joint, i.e. ball stud, is positioned outside of the wheel rim and the electronic module with the fitting is positioned on the inside of the wheel rim and inside the tyre.

The ball stud of the ball joint has a diameter that is greater than a diameter or width of the connection stem. The ball stud, therefore, extends laterally outwardly or radially substantially symmetrically from a longitudinal axis of the connection stem and provides a head having a diameter that is greater than a diameter or width of the connection stem. The ball stud provides a spherical joint surface which is larger than a hemisphere and, therefore, allows additional radial movement of the ball socket around the ball stud with respect to the longitudinal axis of the connection stem.

In some embodiments, the fitting in the electronic module comprises an aperture. The connection stem may be aligned with or positioned in and extend through the aperture.

In some embodiments, the connection stem comprises an inner thread and is engaged with a screw to secure the valve stem with the fitting and the electronic module. The connection stem and the screw are positioned on opposing sides of the aperture of the fitting. The screw is positioned within the tyre and the connection stem extends through the wheel rim such that the ball joint is positioned on the outside of the wheel rim.

The connection stem may extend through the aperture from a first side of the fitting and be secured to the fitting by a screw engaging with the inner thread, the screw being positioned on a second side of the fitting that opposes the first side.

In some embodiments, the fitting comprises a mounting plate comprising the aperture and one or more lateral gusset plates. The mounting plate and the lateral gusset plates may extend substantially perpendicularly to the upper surface of the housing of the electronic module. The lateral gusset plate(s) may be positioned at the end(s) of the mounting plate and provide mechanical support for the mounting plate. The fitting may have an L-shape in plan view, in the case of one lateral gusset plate or a U-shape in plan view in the case of two lateral gusset plates.

In some embodiments, the electronic module includes a housing that accommodates a tyre pressure sensor unit.

The invention is also directed to a method for mounting a tyre parameter monitoring system to a wheel rim as defined in claim <NUM>. The method comprises providing an adapter having a ball stud and a connection stem, inserting the connection stem into a hole in an outer surface of the wheel rim, securing the connection stem to an electronic module positioned on an inner surface of the wheel rim and engaging the ball stud with a ball socket of a valve stem to provide an articulated ball joint between the valve stem and the adapter, placing a seal and a washer over the valve stem positioned on an outer surface of the wheel rim and securing the valve stem to the outer surface of the wheel rim by a nut engaging with the seal, the washer, an outer thread of the valve stem and the outer surface of the wheel rim. The nut positioned on the outer surface of the wheel rim is tightened to clamp the seal and washer between the valve stem and the wheel rim, thus pulling the valve stem inside the washer, exerting pressure on the ball socket and blocking rotation of the valve stem around the head of the ball joint so as to provide an auto locking mechanism.

Thus, a clamp-in type valve stem is coupled to a snap-in electronic module by means of the adapter. The adapter enables the valve stem to be positioned at different angles to the electronic module by means of the articulated ball joint between the valve stem and the adapter. The angle between the connection stem of the adapter and the snap-in electronic module is fixed.

The connection stem may be secured to the snap-in housing by a screw connection.

For example, the connection stem may be inserted into an aperture in the snap-in housing and engaged to the snap-in housing by means of a screw positioned on the opposing side of the aperture that engages with an inner thread of the connection stem. In some embodiments, the connection stem comprises an outer thread which is engaged with a nut positioned on the opposing side of the aperture.

The articulated ball joint formed by the ball stud and the ball socket also provides a self-adjustment mechanism to fix the angle between the valve stem and the electronic module when the valve stem and the electronic module are engaged with the wheel rim. This fixes the position of the sensor on the wheel rim during spinning. As the valve stem is placed on the wheel rim, the valve angle can be easily adjusted in order to fit the electronic module onto the wheel rim. After the initial fitting has been completed and the electronic module touches the wheel rim well, the nut positioned on the opposing side of the wheel rim is tightened to clamp the seal and washer between the valve stem and the wheel rim. This also has the effect of pulling the valve stem. Pulling the valve stem inside the seal and washer exerts pressure on the ball socket and blocks the rotation of the valve stem around the ball stud so as to provide an auto locking mechanism. The torque applied to the nut may be <NUM>, which is sufficient to maintain the valve stem and the sensor in the desired position during high acceleration spinning.

The electronic unit module can be used with a snap-in type of valve and a clamp-in type of valve whilst maintaining the flexible positioning, in particular, variable angle between the clamp-in valve and the electronic module.

Embodiments will now be described with reference to the drawings.

<FIG> illustrates an exploded view and <FIG> illustrates an assembled view of the components of a tyre parameter monitoring system <NUM>, in particular a tyre pressure monitoring system, according to an embodiment of the invention. The tyre parameter monitoring system <NUM> includes an electronic module <NUM> which includes a fitting <NUM> for a snap-in valve, a ball stud <NUM> coupled to the fitting <NUM> and, therefore, to the electronic module <NUM> and a valve stem <NUM> for a clamp-in valve.

The valve stem <NUM> has a substantially elongate shape with a ball socket <NUM> formed in an inner surface at one end <NUM> of the valve stem <NUM>. The ball socket <NUM> can be seen in <FIG>. The valve stem <NUM> may be outwardly flared at the end <NUM> to form the ball socket <NUM> such that the valve stem has a flange at the end <NUM>.

The ball socket <NUM> is coupled to the ball stud <NUM> such that the valve stem <NUM> is positionable at different angles to the electronic module <NUM>. The ball stud <NUM> includes a connection stem <NUM> which extends from one side of the ball stud <NUM> and which is coupled to the fitting <NUM> of the electronic module <NUM>. The ball stud <NUM> has a diameter that is greater than a diameter or width of the connection stem <NUM>. The electronic module <NUM> includes a housing in which the electronics for the sensor(s) for the tyre parameter monitoring system are positioned.

In some embodiments, the fitting <NUM> of the electronic module <NUM> includes an aperture <NUM>. The connection stem <NUM> is aligned with, and may extend through, the aperture <NUM> at an outer side <NUM> of the fitting <NUM>. The connection stem <NUM> may include an inner thread which is coupled to a screw <NUM> positioned on an opposing inner side <NUM> of the fitting <NUM>. In some embodiments, the fitting <NUM> includes a mounting plate <NUM> which may be supported by one or more lateral gusset plates <NUM>. The tyre parameter monitoring system <NUM> may also include a seal <NUM>, a washer <NUM> and a nut <NUM> which are adapted to fit over the valve stem <NUM>.

<FIG> illustrate the tyre parameter monitoring system <NUM> mounted on a wheel rim <NUM>. <FIG> illustrates the tyre parameter monitoring system <NUM>, which does not form part of the presently claimed invention, equipped with a snap-in valve <NUM> mounted on a wheel rim <NUM> at a fixed angular position.

<FIG> illustrates the tyre parameter monitoring system <NUM> equipped with a clamp-in valve. The clamp-in valve has the valve stem <NUM> that enables the system to be mounted at an adjustable angle on the wheel rim <NUM>. The clamp-in valve is mounted on the wheel rim <NUM> at a convenient angle for the best fitment due to the valve stem <NUM>. The angular position between the valve stem <NUM> and the electronic module <NUM> varies. The electronic module <NUM> and a base portion of the connection stem <NUM> are positioned on an inner surface <NUM> of the wheel rim <NUM> and, in operation, within the tyre. The valve stem <NUM>, the ball stud <NUM>, the seal <NUM>, the washer <NUM> and the nut <NUM> are positioned on an outer surface <NUM> of the wheel rim <NUM>.

The tyre parameter monitoring system <NUM> is mounted on the wheel rim <NUM> by inserting the connection stem <NUM> into a hole <NUM> in the wheel rim <NUM> from the outer surface <NUM> of the wheel rim <NUM> and securing it to the fitting <NUM> of the electronic module <NUM> which is positioned on the inner surface <NUM> of the wheel rim <NUM>. The connection stem <NUM> may be secured to the fitting <NUM> by use of the screw <NUM>. The ball joint <NUM> is arranged on the outer surface <NUM> of the wheel rim <NUM>. The ball stud <NUM> is engaged with the ball socket <NUM> of the valve stem <NUM> such that the connection stem <NUM> of the ball stud <NUM> protrudes from the axial end <NUM> of the valve stem <NUM>. The valve stem <NUM> may be locked into position with respect to the electronic module <NUM> by placing the seal <NUM>, the washer <NUM> and the nut <NUM> over the valve stem <NUM> and by tightening the nut <NUM> onto an outer thread <NUM> of the valve stem <NUM> so as to pull the ball stud <NUM> into the ball socket <NUM> to lock the angular position of the valve stem <NUM> with respect to the connection stem <NUM> and the electronic module <NUM> and to secure the valve stem <NUM> onto the outer surface <NUM> of the wheel rim <NUM>.

The articulated ball joint provided between the ball stud <NUM> and the ball socket <NUM> enables the angle between the valve stem <NUM> and the electronic unit <NUM> to vary, thus enabling the tyre parameter monitoring system <NUM> to be used on different types of wheel rim.

Claim 1:
A tyre parameter monitoring system (<NUM>), comprising:
an electronic module (<NUM>) with a fitting (<NUM>);
a ball stud (<NUM>) coupled to the fitting (<NUM>);
a valve stem (<NUM>), the valve stem (<NUM>) having a ball socket (<NUM>) that is coupled to the ball stud (<NUM>) to form a ball joint such that the valve stem (<NUM>) is positionable at different angles to the electronic module (<NUM>);
a nut (<NUM>), a washer (<NUM>) and a seal (<NUM>) placed over the valve stem,
characterized in that in use the position of the valve stem (<NUM>) with respect to the electronic module (<NUM>) may be fixed by securing the nut (<NUM>), the washer (<NUM>) and the seal (<NUM>) to a distal end of the valve stem (<NUM>) and to a wheel rim (<NUM>),
wherein in a mounted position the nut (<NUM>) is positioned on an outer surface (<NUM>) of the wheel rim (<NUM>) and is tightened to clamp the seal and washer between the valve stem (<NUM>) and the wheel rim (<NUM>), thus pulling the valve stem (<NUM>) inside the washer (<NUM>), exerting pressure on the ball socket (<NUM>) and blocking rotation of the valve stem (<NUM>) around the ball stud (<NUM>) so as to provide an auto locking mechanism