Maximum temperature range indicator
US4058014A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1976 |
| Grant date | Nov 15, 1977 |
| Priority date | — |
| Expiry date | Jul 16, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K11/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To detect and record the highest operating temperature range which occurs in an engine, transmission, implement hydraulic system or the like during an extended period of time, an indicator device is adapted to be mounted in thermal contact with a liquid coolant flow, lubricant flow or the like of the apparatus. The device has a housing containing a plurality of electrical resistor segments connected in series between an external electrode and the housing. A plurality of temperature-sensitive switches are arranged to short out successive ones of the resistor segments upon the occurrence of successively higher predetermined temperatures. The maximum temperature range which has been reached over an extended period of operating time may then be determined by using an ohmmeter to measure the electrical resistance between the electrode and the housing since the shorting out of successive ones of the resistor segments, upon the occurrence of successively higher temperature ranges, progressively reduces the electrical resistance in the circuit. The temperature-sensitiveswitches may be a series of springs each initially held in a compressed state by a body of wax wherein the spring expands …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.