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:
Oct. 29, 1996
Filed:
May. 26, 1994
Sanjay Kamani, Unionville, CT (US);
John K Salmon, South Windsor, CT (US);
Otis Elevator Company, Farmington, CT (US);
Abstract
Ultrasonic waves may be emitted from a transmitter/receiver sonic transducer, or separate transmitter working with a separate receiver, directly or reflected into the opening between doors of an elevator; responses reflected from objects or passengers between the doors which are received within a window of response are utilized to create a door reversal signal. The ultrasonic waves may be shaped into a curtain or sheet by means of a hyperbolic reflector opening downwardly toward the doors. To equalize time of travel for sound waves emanating from a single source on one side to all parts of the door opening, the reflector may also have a parabolic shape. The sound waves may be emitted in a cylindrical pattern to accommodate elevators having circular doors. Multiple reflectors may include a convex reflector to spread the sound waves vertically.