US3129335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photosensitive railroad surveying system
Assignee: Individual
•
Filing: 1961-06-30
•
Granted: 1964-04-14
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Expires: 1981-06-30
Abstract
No abstract record available.
Inventors
- 👤 Stewart John Kenneth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:27
CPC Classifications
B; B61; B61L; B61L1/00; B61L1/02; B61L1/10; E; E01; E01B; E01B35/00; E01B2203/00; E01B2203/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
133 words
A SYSTEM FOR RAILROAD SURVEYING, COMPRISING A LIGHT TRANSMITTER ADAPTED TO TRANSMIT A BEAM OF LIGHT, MOUNTED FOR MOVEMENT ALONG A RAILROAD TRACK, A LIGHT BEAM RECEIVER MOUNTED FOR MOVEMENT ALONG THE TRACK, SHADOW BOARD MEANS MOUNTED FOR MOVEMENT ALONG THE TRACK BETWEEN TRANSMITTER AND RECEIVER AND ADJACENT THE RECEIVER, MEANS RESPONSIVE TO BEAM RECEPTION TO INDICATE THE CONDITION OF THE TRACK SURFACE, SAID LIGHT BEAM RECEIVER INCLUDING A PARABOLIC REFLECTOR ORIENTED TO RECEIVE THE TRANSMITTED LIGHT BEAM, A PHOTOELECTRIC CELL LOCATED AT THE FOCAL POINT OF THE REFLECTOR, MASKING MEANS TO MASK OFF BETWEEN AT LEAST ONE-QUARTER AND LESS THAN ONE-HALF OF THE UPPER PART OF THE REFLECTOR WHEN LOOKING IN THE DIRECTION OF THE TRANSMITTED BEAM AND A LIGHT FILTER IN THE PATH OF THE BEAM IN FRONT OF THE REFLECTOR.
Claim 2
Independent Claim
133 words
A SYSTEM FOR RAILROAD SURVEYING, COMPRISING A LIGHT TRANSMITTER ADAPTED TO TRANSMIT A BEAM OF LIGHT, MOUNTED FOR MOVEMENT ALONG A RAILROAD TRACK, A LIGHT BEAM RECEIVER MOUNTED FOR MOVEMENT ALONG THE TRACK, SHADOW BOARD MEANS MOUNTED FOR MOVEMENT ALONG THE TRACK BETWEEN TRANSMITTER AND RECEIVER AND ADJACENT THE RECEIVER, MEANS RESPONSIVE TO BEAM RECEPTION TO INDICATE THE CONDITION OF THE TRACK SURFACE, SAID LIGHT BEAM RECEIVER INCLUDING A PARABOLIC REFLECTOR ORIENTED TO RECEIVE THE TRANSMITTED LIGHT BEAM, A PHOTOELECTRIC CELL LOCATED AT THE FOCAL POINT OF THE REFLECTOR, MASKING MEANS TO MASK OFF BETWEEN AT LEAST ONE-QUARTER AND LESS THAN ONE-HALF OF THE UPPER PART OF THE REFLECTOR WHEN LOOKING IN THE DIRECTION OF THE TRANSMITTED BEAM AND A LIGHT FILTER IN THE PATH OF THE BEAM IN FRONT OF THE REFLECTOR.
References Cited (Backward Citations)
CA650557A
Cited
US2564461A
Cited
US2884564A
Cited
US2789260A
Cited
US2974607A
Cited
US2984747A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-04-14 | 1967-10-14 | 1968-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-04-14 | 1971-10-14 | 1972-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-04-14 | 1975-10-14 | 1976-04-14 | $7700.00 | Window Closed / Lapsed |