US3594775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for detecing frost, snow and ice on a road surface
Assignee: Individual
•
Filing: 1969-07-09
•
Granted: 1971-07-20
•
Expires: 1989-07-09
Abstract
Abstract A transducer has a member with a sensing surface located in the road level which member, when dry and a controlled heat is applied thereto has a basically linear time-temperature curve. The forming of ice on the sensing surface modifies the linear curve by effecting a holdup in the temperature rise due to the heat of fusion of the ice. The resultant heating curve characteristics of the sensing surface are converted to voltage by a thermocouple means, and the variations in the voltage effected by the holdbacks in the heating curve are double differentiated to produce the second derivative of the initial time-temperature curve. Voltage excursions that exceed predetermined positive and negative levels within specified time intervals are utilized to indicate an icy road condition.
Inventors
- 👤 Norbert K Fox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:18
CPC Classifications
G; G01; G01W; G01W1/00; G01W1/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
156 words
A system for detecting the presence of ice, snow, frost and icing conditions on a surface as a function of the heat of fusion relative to time and temperature to provide an indication of the existence of such conditions comprising: a. a transducer having a sensing member mounted in said surface, b. means for heating said sensing member at controlled heat rate for predetermined time period, c. thermocouple means for sensing the temperature of said member during the heating period, d. voltage amplification means connected to said thermocouple means, e. means for feeding the voltage output of said amplification means into a double differentiator, f. means for reading out the voltage level of positive and negative excursions of the output of the double differentiator that occur only during a predetermined time interval within said heating period, and g. means for utilizing said read out voltage levels to provide an indication of the existence of said conditions.
Claim 2
Independent Claim
156 words
A system for detecting the presence of ice, snow, frost and icing conditions on a surface as a function of the heat of fusion relative to time and temperature to provide an indication of the existence of such conditions comprising: a. a transducer having a sensing member mounted in said surface, b. means for heating said sensing member at controlled heat rate for predetermined time period, c. thermocouple means for sensing the temperature of said member during the heating period, d. voltage amplification means connected to said thermocouple means, e. means for feeding the voltage output of said amplification means into a double differentiator, f. means for reading out the voltage level of positive and negative excursions of the output of the double differentiator that occur only during a predetermined time interval within said heating period, and g. means for utilizing said read out voltage levels to provide an indication of the existence of said conditions.
Claim 3
Independent Claim
173 words
A system for detecting on a sensing surface the presence of a substance having an appreciable latent heat by utilizing the latent heat as a function of time and temperature to provide an indication of the existence of such substance comprising: a. a transducer having a member with a substance sensing surface, b. means for heating said sensing member at controlled rate of heat for a predetermined time period to produce a time-temperature curve having linear characteristics, c. thermocouple means for sensing the temperature of said sensing member during the heating period, d. a double differentiator circuit for receiving the voltage output of said thermocouple means to indicate any voltage hold backs in said time-temperature curve of the sensing member, e. means for reading out the voltage level of positive and negative excursions of the output of said double differentiator circuit that occur only during a predetermined time interval within said heating period, and f. means for utilizing said read out voltage levels to provide an indication of the existence of said substance.
Claim 4
Independent Claim
173 words
A system for detecting on a sensing surface the presence of a substance having an appreciable latent heat by utilizing the latent heat as a function of time and temperature to provide an indication of the existence of such substance comprising: a. a transducer having a member with a substance sensing surface, b. means for heating said sensing member at controlled rate of heat for a predetermined time period to produce a time-temperature curve having linear characteristics, c. thermocouple means for sensing the temperature of said sensing member during the heating period, d. a double differentiator circuit for receiving the voltage output of said thermocouple means to indicate any voltage hold backs in said time-temperature curve of the sensing member, e. means for reading out the voltage level of positive and negative excursions of the output of said double differentiator circuit that occur only during a predetermined time interval within said heating period, and f. means for utilizing said read out voltage levels to provide an indication of the existence of said substance.
Claim 5
Dependent Claim
41 words
The detecting system according to claim 2 wherein: a. said predetermined time period is proportional to the latent heat and mass of said substance and inversely proportional to the mass of said sensing member and to said controlled rate of heat.
Claim 6
Dependent Claim
41 words
The detecting systeM according to claim 2 wherein: a. said sensing member is comprised of a material having a mass heatable to the temperature of the latent heat transfer to said substance during the predetermined time interval within said heating period.
Claim 7
Dependent Claim
51 words
The detecting system according to claim 4 including a. a first timing mechanism providing for the heating of said sensing member at equal periodic intervals greater than said heating period, and b. a second timing mechanism operable by said first timing mechanism for controlling the duration of said predetermined time interval.
References Cited (Backward Citations)
US3229271A
Cited
US3412326A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |