Liquid level indicator
Patent 4155013 Issued on May 15, 1979. Estimated Expiration Date: 
October 7, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 7, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2350712 3448616 3454759 3639770 Optical liquid level gauge Patent #: 3995169 InventorApplicationNo. 05/840136 filed on 10/07/1977US Classes:250/577, Volume or level250/341.2, Including probe250/357.1, Fluent material level signalling340/619, Optical sensor73/293With illuminationExaminersPrimary: Segal, RobertAttorney, Agent or FirmInternational ClassesG01F 23/284 (20060101)G01F 23/292 (20060101) AbstractA liquid level monitor using the difference between the refraction of light by a prism in contact with air and by the same prism in contact with liquid being monitored to give warning of low liquid level. In preferred form for monitoring engine oil level, light is transmitted to a prism by an incoming fiber optic lead and returned from the prism by a return fiber optic lead. When the oil level is normal, the prism is in contact with the oil and the incoming light is transmitted into the oil and dissipated. When the oil level drops, the incoming light is reflected by the prism to the return lead and the reflected light is used to provide the indication of low oil level.Field of SearchVolume or level | |
