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. 27, 1992
Filed:
Mar. 30, 1992
Jacob H Hall, Montgomery, AL (US);
Rheem Manufacturing Company, New York, NY (US);
Abstract
A fuel-fired, forced draft heating appliance includes a draft inducer fan having an inlet connected to a vent hood, an outlet connectable to a vent pipe, and an interior housing region in which a negative pressure is generated during normal appliance operation. The vent hood receives hot combustion gases generated by the appliance, and has an inlet for receiving ambient dilution air that mixes with and cools the combustion gases entering the hood and subsequently discharged into the vent pipe by the fan. A combination pressure and temperature limit control is used to sense the presence of an obstruction in either the vent pipe or the vent hood inlet and responsively shut down the appliance. The control includes a vacuum switch external to the fan, a bimetallic disc-type temperature sensor disposed within the negative pressure fan region, and a conduit interconnecting the switch and the temperature sensor. During normal appliance operation an ambient air flow is drawn into the fan housing sequentially through the vacuum switch, the conduit and the temperature sensor. An obstruction in the vent pipe sufficient to reduce this air flow below a predetermined level causes the vacuum switch to responsively shut down the appliance. An undesirably high temperature within the fan, arising for example due to an obstruction in the vent hood inlet, causes the temperature sensor disc to block air flow through the conduit, thereby also causing the vacuum switch to responsively shut down the appliance.