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:
Jan. 16, 1990
Filed:
May. 19, 1988
Gordon P Sharp, Newton, MA (US);
Jerome J Schaufeld, Framingham, MA (US);
Phoenix Controls Corporation, Newton, MA (US);
Abstract
An apparatus for sensing the extent to which the opening of a fume hood is uncovered by the hood sashes, and is particularly adapted for use with hoods having sashes which are moved horizontally. Radiation from a radiation emitter, such as an optical or a magnetic emitter, are sensed by corresponding detectors. For some embodiments of the invention, there is relative movement between the emitters and detectors as the sashes are moved to cover or uncover the opening, the movement between the emitter and the detector being such that the amount of radiation detected by the detectors is proportional to the uncovered portion of the opening. The relative movement may be accomplished by, for example, having the detectors fixed and having the emitters mounted to the sashes or by having the detectors mounted to some sashes and the emitters mounted to other sashes. A unique magnetic emitter is also provided with enhanced flux throw. The enhanced flux throw is required with various embodiments of the invention where there may be substantial spacing between the magnetic emitter and detector. Embodiments are also disclosed for practicing the invention with a fume hood having sashes which are adapted to be opened both vertically and horizontally.