Indicating device, especially for indicating the state of pressure of a tire
First Claim
1. An indicating device for indicating a pressure in a tire, which tire is mounted on a rim to form a wheel which has a rotation axis, the device being mounted on the wheel and comprising;
- a means for measuring the pressure in the tire;
a transducer/transmitter means for converting the measured pressure of the tire to an electrical signal and for transmitting this signal to an electrical unit; and
a source of electrical power for said transducer/transmitter means forming an inductive current generator when the wheel rotates, said source includinga rotor which is fixed to the wheel coaxially to the axis of the wheel so as to rotate with the wheel,a stator which is mounted coaxial with the axis of the wheel so as to be substantially freely rotatable relative to said rotor and about the axis,a first counterweight which is fixed relative to said stator such that, as the wheel and said rotor turn together, said first counterweight keeps said stator substantially motionless with respect to said rotor as said first counterweight overcomes a force of magnetic attraction between said stator and said rotor, anda damping means for damping swinging movement of said first counterweight as the wheel rotates, said damping means including a second counterweight, a mounting means for mounting said second counterweight for free rotation about the axis of the wheel and axially adjacent said first counterweight, and a coupling means for coupling said first counterweight and said second counterweight together to permit only a limited angular displacement about the axis between said first and second counterweights.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention relates to an indicating device, especially for indicating the state of pressure of a tire, of the type that can be fixed to a wheel. The device includes: a mechanism (7) for measuring the pressure of the tire (2); a transducer/transmitter (8) which converts the measured magnitude of the pressure into an electrical signal and transmits the electrical signal to an electronic unit; and a source of electrical power (12, 13) for the transducer/transmitter (8). In order to make the device not only more practical and operationally reliable but also less expensive, the device provides an electrical power source, the power source consists of an inductive current generator formed by a rotor (12) which is fixed coaxially to the wheel so as to rotate as one piece therewith, and by a coaxial stator (13) which is freely rotatable with respect to the rotor (12) and is provided with a counterweight (14),capable of keeping the stator (13) essentially motionless with respect to the rotor (12) as the rotor rotates with the wheel.
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Citations
29 Claims
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1. An indicating device for indicating a pressure in a tire, which tire is mounted on a rim to form a wheel which has a rotation axis, the device being mounted on the wheel and comprising;
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a means for measuring the pressure in the tire; a transducer/transmitter means for converting the measured pressure of the tire to an electrical signal and for transmitting this signal to an electrical unit; and a source of electrical power for said transducer/transmitter means forming an inductive current generator when the wheel rotates, said source including a rotor which is fixed to the wheel coaxially to the axis of the wheel so as to rotate with the wheel, a stator which is mounted coaxial with the axis of the wheel so as to be substantially freely rotatable relative to said rotor and about the axis, a first counterweight which is fixed relative to said stator such that, as the wheel and said rotor turn together, said first counterweight keeps said stator substantially motionless with respect to said rotor as said first counterweight overcomes a force of magnetic attraction between said stator and said rotor, and a damping means for damping swinging movement of said first counterweight as the wheel rotates, said damping means including a second counterweight, a mounting means for mounting said second counterweight for free rotation about the axis of the wheel and axially adjacent said first counterweight, and a coupling means for coupling said first counterweight and said second counterweight together to permit only a limited angular displacement about the axis between said first and second counterweights. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification