US3828309A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for detecting the internal pressure of a tire
Assignee: Bridgestone Corp
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Filing: 1972-12-20
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Granted: 1974-08-06
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Expires: 1992-12-20
Abstract
Abstract Apparatus for detecting the internal pressure of a tire, wherein a magnetic member is attached to a wheel of a vehicle for simultaneous rotation therewith and a coil is mounted on the chassis of the vehicle so that as the wheel rotates, the magnetic member passes by the coil for a voltage to be induced in the coil by electromagnetic induction. There is provided means operable in response to the tire pressure to change the position of the magnetic member relative to the coil, so that when an abnormal drop occurs in the tire pressure, the position of the magnetic member changes with a resulting change in the level or phase of the induced voltage.
Inventors
- 👤 H Yamasaki
- 👤 M Kaida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:32
CPC Classifications
B; B60; B60C; B60C23/00; B60C23/02; B60C23/04; B60C23/0408; B60C23/0422; B60C23/0425
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
175 words
An apparatus for determining change in the internal pressure of a vehicle wheel tire, comprising: electromagnetic means for generating an electric current comprising a stationary member mounted on a vehicle chassis, and a moving member mounted on the vehicle wheel and rotatable therewith, said moving member being disposed relative to the tire at a first tire pressure such that the rotation of the tire brings said moving member periodically into a spaced relationship with said stationary member sufficient to induce a voltage of a given phase into said stationary member; means for changing the angular position of said moving member relative to the wheel in response to a change in the internal pressure of the tire such that the spaced relationship between said moving member and said stationary member brought about by the rotation of the tire at a second tire pressure results in an induced voltage in said stationary member of opposite phase to said given phase; and means for detecting a change in the phase of the voltage induced in said stationary member.
Claim 2
Independent Claim
175 words
An apparatus for determining change in the internal pressure of a vehicle wheel tire, comprising: electromagnetic means for generating an electric current comprising a stationary member mounted on a vehicle chassis, and a moving member mounted on the vehicle wheel and rotatable therewith, said moving member being disposed relative to the tire at a first tire pressure such that the rotation of the tire brings said moving member periodically into a spaced relationship with said stationary member sufficient to induce a voltage of a given phase into said stationary member; means for changing the angular position of said moving member relative to the wheel in response to a change in the internal pressure of the tire such that the spaced relationship between said moving member and said stationary member brought about by the rotation of the tire at a second tire pressure results in an induced voltage in said stationary member of opposite phase to said given phase; and means for detecting a change in the phase of the voltage induced in said stationary member.
Claim 3
Dependent Claim
30 words
An apparatus in accordance with claim 1, wherein said moving member is a permanent magnet, and said stationary member is a coil wound on a coil member of magnetic material.
Claim 4
Dependent Claim
34 words
An apparatus in accordance with claim 2, wherein said angular position changing means includes means for rotating said moving member about a fixes axis positioned at substantially the axial midpoint of said moving member.
Claim 5
Dependent Claim
40 words
An apparatus in accordance with claim 3, wherein said coil member is substantially U-shaped, having two ends, and wherein said moving member is rotated in a plane coincident with the plane defined by said two ends of said coil member.
Claim 6
Dependent Claim
64 words
An apparatus in accordance with claim 4, wherein said position changing means includes a meshed rack gear and pinion gear, said rack gear being movable in response to changes in the internal pressure of said tire, said pinion gear being connected to said movable member, any movement of said rack gear changing the angular position of said pinion gear and said movable member correspondingly.
Claim 7
Dependent Claim
63 words
An apparatus in accordance with claim 5, wherein said movable member is at a first angular position of substantially 45* with respect to a line connecting said two ends of said coil member at said first tire pressure, said movable member being rotated substantially 90* from said first position in response to a change of internal tire pressure to said second tire pressure.
Claim 8
Dependent Claim
36 words
An apparatus in accordance with claim 6, wherein said detecting means includes a flip-flop which is set by one phase of voltage induced in said stationary member and reset by the other phase of induced voltage.
Claim 9
Dependent Claim
150 words
An apparatus in accordance with claim 1, wherein said moving member comprises a pair of permanent magnets spaced apart from each other, one of said permanent magnets being in a position of periodic electromagnetic coupling with said stationary member at said first tire pressure, the other permanent magnet being at a second position spaced away from said first position and not electromagnetically coupled with said stationary member, and wherein said position changing means operates in response to a change in tire pressure to said second tire pressure to move said pair of spaced permanent magnets such that sAid other permanent magnet is in said first position, the polarities of said pair of permanent magnets being so selected that the direction of the electromotive force induced in said stationary means by said one magnet is opposite in phase to the electromotive force induced in said stationary member by said other magnet.
Claim 10
Dependent Claim
53 words
An apparatus in accordance with claim 8, wherein said position changing means includes a spring capable of snap action, which spring maintains said one magnet electromagnetically coupled with said stationary member at said first tire pressure, and brings said other magnet into electromagnetic coupling with said stationary member at said second tire pressure.
Claim 11
Dependent Claim
39 words
An apparatus according to claim 9, including a movable member and a stationary member for each wheel of the vehicle, and further including scanning means for successively applying the voltage induced into said stationary members to said detecting means.
Claim 12
Dependent Claim
87 words
An apparatus in accordance with claim 10, including means associated with each tire and responsive to said detecting means for indicating a change in the internal pressure of a tire, and wherein said scanning means scans said indicating means in synchronism with the applying of induced voltages in said stationary members to said detecting means such that the output of said detecting means is applied successively to the indicating means corresponding to the tire associated with that stationary member which is immediately connected to said detecting means.
Claim 13
Dependent Claim
53 words
An apparatus in accordance with claim 11, wherein said scanning means includes a plurality of AND gates, one of said AND gates being associated with each of said indicating means, and having its output applied thereto, said scanning means and said detecting means being connected as inputs to each of said AND gates.
References Cited (Backward Citations)
US2057556A
Cited
US2629086A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |