The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 21, 2001
Filed:
Dec. 13, 1999
James B. Farr, Ann Arbor, MI (US);
Kent B. Herrick, Manchester, MI (US);
Tecumseh Products Company, Tecumseh, MI (US);
Abstract
A combination sight glass and optical sensor is provided in the housing of a hermetic compressor to provide effective visual inspection in addition to automatic sensing of the level of oil in an oil sump. A sight glass fitting is provided in the housing and has a first portion that extends outwardly from the housing and that is accessible from outside the compressor. An optical oil level sensing device is removably attached to the first portion of the sight glass with electrical leads extending outside the compressor for connection to a compressor controller. A prism or similar device is attached to the sight glass fitting intermediate the sump oil and the optical sensor. The sensing device includes a light source, a photosensitive detector, and an opaque member to prevent cross coupling between the light source and the detector. Should the oil level in the oil sump fall below a predetermined level, the optical sensor sends a low oil level signal to the controller which interrupts power to the compressor or generates an alarm or status signal. A technician may remove the optical sensor from the sight glass fitting and visually inspect the oil level by looking through the sight glass fitting and prism and into the interior of the compressor housing. One embodiment of the optical sensor will also provide a low oil level signal to the controller when the optical sensor is disengaged or removed from the sight glass.