US3581084A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric wheel-axle detector
Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1968-11-06
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Granted: 1971-05-25
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Expires: 1988-11-06
Abstract
Abstract A wheel-axle detector for wheeled vehicles following a track having rails with an I-shaped cross section forming a continuous imperforate web with an opposed overhanging head and foot. A piezoelectric element holder containing a piezoelectric element is inserted directly between the head and the foot of the rail such that a portion of the vehicle wheel load borne on the rail is imparted to the element. A detecting circuit is provided to receive and detect the electrical output of the piezoelectric element.
Inventors
- 👤 Saburo Kaneno
- 👤 Takeshi Yamaguchi
- 👤 Shunichi Yoshioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:15
CPC Classifications
B; B61; B61L; B61L1/00; B61L1/16; B61L1/163; B61L1/164; B61L1/02; B61L1/025; B61L25/00; B61L25/02; B61L25/021
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
21 words
The wheel-axle detector of claim 1 wherein the rails are laid upon ties and said holder is positioned over a tie.
Claim 2
Dependent Claim
15 words
The wheel-axle detector of claim 1 wherein said piezoelectric element is lead zirconate titanate ceramic.
Claim 3
Dependent Claim
51 words
The wheel-axle detector as claimed in claim 1 wherein said piezoelectric element holder includes at least one insulating plate mechanically conducting a portion of the vehicle load to said piezoelectric element and electrically insulating said element, said insulating plate having a spring constant at least equal to that of said element.
Claim 4
Dependent Claim
17 words
The wheel-axle detector of claim 4 wherein said insulating plates are nonelectrically polarized lead zirconate titanate ceramic.
Claim 5
Dependent Claim
31 words
The wheel-axle detector of claim 4 characterized by a pair of couplers having two of said insulating plates holding said element disposed therebetween, and a flexible coupling plate connecting said couplers.
Claim 6
Dependent Claim
54 words
The wheel-axle detector of claim 1 wherein a second piezoelectric element holder containing a second piezoelectric element and said first holder with said first element are positioned directly opposite each other between the head and foot on opposite sides of the same rail, their piezoelectric outputs being additively combined to produce said output signal.
Claim 7
Dependent Claim
27 words
The wheel-axle detector of claim 1 wherein said detecting circuit means includes an oscillator circuit which incorporates said piezoelectric element as a crystal in its tuned circuit.
Claim 8
Dependent Claim
30 words
The wheel-axle detector of claim 8 wherein said oscillator circuit includes a transistor, said piezoelectric element remotely connected through a transmission line between the base and collector of said transistor.
Claim 9
Dependent Claim
17 words
The wheel-axle detector of claim 9 wherein individually shielded signal wires are employed as said transmission line.
Claim 10
Dependent Claim
79 words
The wheel-axle detector of claim 1 wherein said detecting circuit means iNcludes a holding circuit responsive to each output signal of said element to emit a second signal having a duration of predetermined magnitude greater than the time it takes a vehicle to be detected travelling on said track at minimum velocity to travel a distance equal to the maximum distance between adjacent axles of said vehicle but less than the time interval between succeeding vehicles to be detected.
Claim 11
Dependent Claim
82 words
The wheel-axle detector of claim 1 characterized by at least two more of said piezoelectric elements positioned in the same manner as the first at different points along said track and at predetermined distances from said first element and each other, said detecting circuit means connected to receive and operable to independently detect the respective output signals of said element and including an acceleration detection circuit responsive to said independently detected output signals to detect the acceleration of the vehicle being detected.
Claim 12
Dependent Claim
99 words
The wheel-axle detector of claim 1 characterized by a second piezoelectric element positioned in relation to said track in the same manner as said first element to produce a piezoelectric output for each passing vehicle wheel, said second element positioned at a predetermined distance along said track from said first element, said detecting circuit means connected to receive and operable to independently detect the respective output signals of said elements and including a velocity detection circuit response to said independently detected output signals to detect the time required for a vehicle to travel said predetermined distance between said elements.
References Cited (Backward Citations)
US2558563A
Cited
US2755384A
Cited
US2906865A
Cited
US2966582A
Cited
US3086109A
Cited
US3469116A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |