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. 19, 1976
Filed:
Nov. 29, 1974
William J Riordan, Shrewsbury, MA (US);
The Walter Kidde & Company, Inc., Clifton, NJ (US);
Abstract
Disclosed herein is a fuel burner control system with a purge timer having a current responsive control relay that is energized into an active state only by a given minimum input current level but can be maintained in that active state by a substantially lesser input current level. After connection to an electrical supply an activating circuit supplies the given input current level to the control relay only after a predetermined purge time period established by an electrical timer, after which a hold circuit supplies the lesser input current level maintaining the relay in its active state. A blower dissipates any residual fuel vapor in the vicinity of the burner during the purge period and only after its conclusion is fuel flow initiated and ignition attempted in response to contact closures effected in the relay's active state. In a preferred embodiment of the invention, the purge timer comprises an energy storage capacitor which is charged from the supply during the purge period after which a threshold device dumps the energy stored in the capacitor to produce the current level required to move the control relay into its active state.