Tire pressure pick-up

• US 4,386,247 A
• Filed: 08/03/1981
• Issued: 05/31/1983
• Est. Priority Date: 08/05/1980
• Status: Expired due to Fees

• Current Assignee: Societe Anonyme D.B.A.
• Original Assignee: Societe Anonyme DBA
• Inventors: Couat, Serge
• Primary Examiner(s): Grimley, A. T.
• Assistant Examiner(s): Ginsburg, Morris
• Application Number:
  US06/289,021
• Time in Patent Office: 666 Days
• Field of Search: 200/61.25, 200/83 R, 200/83 WM, 200/80 A, 200/80 B, 200/80 C, 200/80 D, 200/80 F, 200/80 J, 200/80 L, 200/80 N, 200/80 P, 200/80 Q, 200/80 S , 200/80 SA, 200/80 T, 200/80 V, 200/80 Y, 200/80 W, 200/80 Z, 200/61.26, 200/61.22, 200/8 R, 307/118, 340/58, 73/146, 73/146.2, 73/146.3, 73/146.4, 73/146.5, 73/146.8
• US Class Current: 200/61.25
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0498 for rim attachments B60C23/0494, B60C23/0496 take precedence
• CPC Class Codes: H01H 35/34 actuated by diaphragm

Abstract

The pressure pick-up is of the type comprising an elastic metal diaphragm deformable between a first and a second state according as the pressure in the tire is lower or higher than a predetermined value, and an electrical switch controlled by the diaphragm. In accordance with the invention the metal diaphragm has the form of a spherical dome mounted to bear with its edge free at the periphery of its concave face against a seating, its convex face being subjected to the pressure in the tire.

Claims

1. Pressure pick-up device for comparing a pressure to be measured with a reference pressure comprising a housing having a wall defining a chamber therewithin, a resilient diaphragm mounted in said chamber and shiftable between first and second conditions when the pressure differential across said diaphragm increases to a predetermined amount, said diaphragm having a pair of opposite sides, one of said sides being adapted for communication to the pressure to be measured, the other side being adapted for communication to the reference pressure, and switch means responsive to shifting of said diaphragm between said first and second conditions, said diaphragm having a concave portion and a peripheral outer edge circumscribing said diaphragm, said switch means including a seating member engaged by the concave portion of the diaphragm as the latter shifts between said first and second conditions, a peripheral portion of said diaphragm cooperating with the wall of the housing to define a space between the peripheral edge and the wall to permit free movement of said peripheral edge toward and away from the wall when diaphragm shifts between the first and second conditions.

2. The invention of claim 1, and sealing means carried by said housing and sealingly engaging the peripheral portion of said diaphragm.

3. The invention of claim 1, wherein said housing is made of an electrically insulative material and said seating member and said diaphragm are made of an electrically conductive material.

4. The invention of claim 1, wherein said switch means includes an annular conductive area circumscribing said seating member, the peripheral portion of the diaphragm engaging said annular conductive area.

5. In combination, a rim, a tire mounted on said rim, and a pressure pick-up responsive to the pressure in said tire, said tire pressure pick-up comprising a housing having a wall defining a chamber therewithin, a resilient diaphragm mounted in said chamber and shiftable between first and second conditions when the pressure differential across said diaphragm increases to a predetermined amount, said diaphragm having a pair of opposite sides, one of said sides being communicated to the pressure in said tire, the other side communicated to a reference pressure, and switch means responsive to shifting of said diaphragm between said first and second conditions, said diaphragm having a concave portion and a peripheral outer edge circumscribing said diaphragm, said switch means including a seating member engaged by the concave portion of the diaphragm as the latter shifts between said first and second conditions, a peripheral portion of said diaphragm cooperating with the wall of the housing to define a space between the peripheral edge and the wall to permit free movement of said peripheral edge toward and away from the wall when the diaphragm shifts between the first and second conditions.

6. The invention of claim 5, and sealing means carried by said housing and sealingly engaging the peripheral portion of said diaphragm.

7. The invention of claim 5, wherein said housing is made of an electrically insulative material and said seating member and said diaphragm are made of an electrically conductive material.

8. The invention of claim 7, wherein said housing includes a first projection portion adapted to be installed into the opening of a valve carried by said tire, and a second projecting portion extending opposite from the first projecting portion, said seating member terminating in an electrical contact extending into said second projecting portion.

9. The invention of claim 5, wherein said switch means includes an annular conductive area circumscribing said seating member, the peripheral portion of the diaphragm engaging said annular conductive area.

10. The invention of claim 9, wherein said housing includes a body portion and an annular projecting portion circumscribing said diaphragm and cooperating with the body portion to define a shoulder between said annular projecting portion and said body portion, and a flexible membrane closing said projection, said housing being mounted in an opening in said rim whereby said shoulder engages said rim and said projecting portion extends into said opening, said membrane being substantially at the level of the inner surface of the rim.