Patent Application
20080216566
1. Field of the Invention
The present invention relates to an improved apparatus and method for securing a remote tire pressure monitoring sensor to the inner surface of a tire.
2. The Prior Art
It is well known in the art to use SAW devices to remotely detect the pressure within a vehicle tire. The sensor is mounted to the inner surface of either the wheel or the tire so that it is exposed to the pressurised environment therein, and is remotely interrogated in order to determine the pressure within the pressurised environment. Applicant's own earlier British Patent Application No. 0127137.8 discloses a flexible patch having an upstanding post on the end of which the sensor is mounted so as to be decoupled from the stress-field in the patch, and patch having an adhesive on its surface remote from the post by means of which it is attachable to the inner surface of a tire.
This solution for attaching the sensor to the tire is acceptable for applications such as truck tires which are re-treaded and have a service life of many hundreds of thousands of miles. But for passenger cars and the like, for which the tires have a much shorter service life, simply disposing of the sensor with the tire when the tire is changed is less acceptable as the cost implication is much greater, and it is therefore desirable for the sensor to be removable from the old tire and re-useable on the new one.
According to the present invention there is provided a reusable tire pressure sensor comprising a housing member having a first surface by means of which the housing member is permanently attachable to a surface within the pressurised region of a wheel/tire assembly and a pocket formed in the surface remote from said first surface, a pressure sensor being removably mountable in said pocket in order to measure the pressure within the pressurised region of the wheel/tire assembly.
A reusable sensor in accordance with the invention has the advantage that it enables the more expensive sensor portion of the assembly to be removed when the tire reaches the end of its serviceable life and transferred to a new tire, thereby reducing cost.
Preferably, the sensor is mounted on a patch generally as described above from the prior art but without any adhesive on it, the main body of the patch being inserted into the pocket in the housing with the post protruding from the pocket. This has the advantage that the post acts to locate the patch within the housing and hold it in place. More particularly, the patch is a rubber patch which may be folded in order to be inserted through an opening in the housing so as to mount it within the pocket—the opening being smaller than the unfolded patch. Forming the housing of rubber then has the additional advantage that the cohesion between the rubber of the housing and the patch further operates to prevent movement of the patch within the housing.
The housing may advantageously be formed by a patch itself which has a region which is free of adhesive that is surrounded or at least bound on two sides by regions which carry adhesive, the pocket then being formed between the said adhesive free region and the region of the wheel 1 tire assembly underlying said adhesive free region. An opening is then formed in the upper surface of said adhesive free region by means of which the sensor may be inserted into and removed from the pocket.
The housing may be of unitary construction or may be formed as separate parts joined together. For example, the adhesive free region may be separately formed from the or each adhesive carrying region and be attached to an upper surface thereof.
The housing may particularly effectively be round or oval and have an oval opening by means of which the sensor is inserted into or removed from the pocket.
In order that the invention may be well understood, there will now be described an embodiment thereof, given by way of example, reference being made to the accompanying drawings, in which:
Referring first to
The sensor patch 2 may then easily be removed by a user by simply pulling on the exposed end of the patch, application of sufficient force deforming the flange portion of the patch and allowing sensor patch carrying the sensor to be removed from the pocket 5 and mounted in the housing of another tire.
According to an alternate embodiment illustrated by dashed lead lines, there is provided a sensor patch or sensor base 16 which is removably positioned within the pocket 5 of mounting patch 1. A post 18 is mounted on base 16. Base 16 is foldable to pass through aperture 7 and then unfold within pocket 5, thereby being retained within the pocket, until forceably removed. Post 18 protrudes through aperture 7. Pressure sensor 20 is mounted on post 18.
It will of course be understood that the housing may be separately formed and permanently fastened to a wheel/tire assembly or may be integrally formed with the wheel or tire. It may also be formed in a variety of shapes.
| Number | Date | Country | Kind |
|---|---|---|---|
| GB0710725.3 | Jun 2007 | GB | national |
