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:
Feb. 21, 1978
Filed:
Nov. 12, 1975
Joseph M Rait, Buffalo, NY (US);
Other;
Abstract
Sensing devices responsive to changes in the physical condition of the area in which they are located are disposed in elongate, flexible carriers to form a detecting unit which can be arranged in a tortuous, undulating array to cover an undefined area of any shape desired with a detecting density of any chosen value. The detecting unit can assume various forms including that of a pair of conducting elements disposed within an insulating tube in opposed relation positioned to complete the continuity of a switching circuit when the tube is flexed to cause engagement of the conductors. Another embodiment comprises a plurality of braided strands of insulating material extending lengthwise within an insulating carrier cable sheath. A pair of conductors is included in the braiding in a spiral disposition with each conductor being disposed along the entire length in opposed relation to the other conductor. Another embodiment includes a closed tubular element filled with an inelastic fluid having a servomechanism at one end to actuate a switching device for an electric alarm circuit in response to a change in liquid level. A modification of this embodiment would include a light responsive element in lieu of a servomechanism of a sensitivity so as to respond to a change in light transmission due to the interference of the liquid when the liquid level moves to a position which interferes with the light transmission source or the ambient light.