Patent ID: 6194998
Filing Date: 2001-02-27
Classification: B60C

Abstract:
A power supply unit adapted for use with a pressure-sensing device for a vehicle wheel, the vehicle wheel including a wheel rim and a pneumatic tire mounted on the wheel rim so as to confine an airtight chamber therewith, the pressure-sensing device being mounted on the wheel rim inside the airtight chamber and being concealed by the pneumatic tire, said power supply unit comprising:a tubular valve housing having an outer end portion, an inner end portion and an intermediate portion between said outer and inner end portions, said valve housing confining a longitudinal air passage that extends from said outer end portions through said inner end portion, said intermediate portion being adapted to be mounted on the wheel rim in an airtight manner such that said inner end portion extends into the airtight chamber and such that said outer end portion extends outwardly of the wheel rim, said valve housing being provided with a housing conductor that extends from said outer end portion to said inner end portion and that is adapted to be connected electrically to the pressure-sensing device;an air valve member mounted in said air passage of said valve housing and operable so as to control air flow through said air passage, said air valve member including a spring-loaded valve stem with a conductive stem body that is adapted to be connected electrically to the pressure-sensing device, and insulation means for electrically insulating said stem body from said housing conductor; anda battery housing mounted on said outer end portion of said valve housing and adapted to receive a battery cell therein, said battery housing being provided with electrically isolated first and second battery contacts adapted to connect electrically and respectively with first and second terminals of the battery cell when the battery cell is received in said battery housing, said first and second battery contacts establishing electrical connection with said housing conductor and said conductive stem body, respectively, when said battery housing is mounted on said outer end portion of said valve housing, said battery housing including a connecting portion for removable mounting on said outer end portion of said valve housing, and a battery confining portion adapted to receive the battery cell therein, said first battery contact being provided in said battery confining portion, said second battery contact being mounted in said battery housing at a junction of said connecting portion and said battery confining portion, said valve housing and said battery housing being made from an electrically conductive material such that said valve housing is provided inherently with said housing conductor, and such that said first battery contact is connected electrically to said valve housing via said battery housing, said battery housing having a positioning member made from an insulator material and disposed at the junction of said connecting portion and said battery confining portion, said second battery contact being mounted on said positioning member and having a first portion that extends into said battery confining portion and that is adapted to contact the second terminal of the battery cell, and a second portion that extends into said connecting portion and that contacts said conductive stem body when said battery housing is mounted on said outer end portion of said valve.