Pneumatic pressure sensor switch device for a vehicle tire
First Claim
1. A pneumatic pressure sensor switch device for a pneumatic tire, comprising means in addition to said switch device for mounting said switch device inside the inflation chamber of the tire, a sensor having a closed chamber filled with gas at a pressure above atmospheric pressure, one of the walls of the chamber being a flexible diaphragm, of which the surface remote from the chamber is exposed to the pressure in the inflation chamber of the tire, a movable electric switch contact point cooperating with a stationary switch contact point on the chamber, said movable contact point being provided on a movable part cooperating with the diaphragm so that the diaphragm moves said contact point out of contact with said stationary contact point at predetermined pressures in the tire and allows said contact points to make electrical contact at lower pressures in the tire, said sensor being taken up in an electric circuit with means to take up a source of electric energy and a transmitter to give radio signals to the outside of the tire when said circuit is closed.
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Accused Products
Abstract
A pneumatic sensor switch for giving a warning signal if a pneumatic vehicle tire has too low pressure has a gas-filled chamber, separated from the inflation space in the tire by a flexible diaphragm cooperating electrically with a metal part in the chamber to form an electric switch open at safe pressures in the tire and closed at dangerous lower pressures. There is an electric circuit with battery and transmitter to transmit warning signals to the outside if the switch is closed. There may be a second chamber with an electric switch contact, filled with gas at a lower pressure and also separated from the inflation space in the tire by a flexible diaphragm so that the contact is open at atmospheric pressure therein and closed by the diaphragm at higher pressures. The electric switches of both chambers are connected in series so that a warning signal is given only at pressures in the dangerous range, when both switches are closed, and not at atmospheric pressure nor at safe operating pressures in the tire.
18 Citations
15 Claims
- 1. A pneumatic pressure sensor switch device for a pneumatic tire, comprising means in addition to said switch device for mounting said switch device inside the inflation chamber of the tire, a sensor having a closed chamber filled with gas at a pressure above atmospheric pressure, one of the walls of the chamber being a flexible diaphragm, of which the surface remote from the chamber is exposed to the pressure in the inflation chamber of the tire, a movable electric switch contact point cooperating with a stationary switch contact point on the chamber, said movable contact point being provided on a movable part cooperating with the diaphragm so that the diaphragm moves said contact point out of contact with said stationary contact point at predetermined pressures in the tire and allows said contact points to make electrical contact at lower pressures in the tire, said sensor being taken up in an electric circuit with means to take up a source of electric energy and a transmitter to give radio signals to the outside of the tire when said circuit is closed.
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9. A pneumatic pressure sensor switch device for a pneumatic tire, comprising means for mounting said switch device inside the inflation chamber of the tire, two chambers, each having a flexible diaphragm as one of its walls, which diaphragms are, on their opposite surface, exposed to the pneumatic pressure in the inflation chamber of the tire, both chambers having electrical contact means operated by their diaphragm and electrically connected in series and to a transmitter to generate signals to be received outside the tire if an electric circuit through the transmitter is closed by both diaphragms, in which one of the chambers is filled with gas at a pressure much lower than the normal pressures in the inflation chamber of the tire, the electrical contact means in this chamber being open at atmospheric pressure on the outside of its diaphragm and being closed by movement of said diaphragm at higher pressures thereon.
- 10. A pneumatic pressure sensor switch device for a pneumatic tire, comprising means for mounting said switch device inside the inflation chamber of the tire, a sensor having a closed chamber filled with gas at a pressure above atmospheric pressure, one of the walls of the chamber being a flexible diaphragm, of which the surface remote from the chamber is exposed to the pressure in the inflation chamber of the tire, a movable electric switch contact point cooperating with a stationary switch contact point on the chamber, said movable contact point being provided on a movable part cooperating with the diaphragm so that the diaphragm moves said contact point out of contact with said stationary contact point at predetermined pressures in the tire and allows said contact points to make electrical contact at lower pressures in the tire, said sensor being taken up in an electric circuit with means to take up a source of electric energy and a transmitter to give radio signals to the outside of the tire when said circuit is closed, there being also a second sensor with a closed second chamber filled with gas at a lower pressure than the pressure in the other chamber, said second chamber having a second flexible diaphragm as one of its walls, exposed to the pressure in the inflation chamber of the tire, said second diaphragm carrying an electric contact point cooperating electrically with a fixed contact point in this second sensor so that the said contact points are out of contact at atmospheric pressure in the tire and are in contact by movement of the diaphragm at higher pressures in the tire, this second sensor being connected with its contact points in series in the said electric circuit of the first-said sensor.
Specification