SENSING MEANS FOR ELECTRIC FAN HEATER

• US 3,731,057 A
• Filed: 06/21/1971
• Issued: 05/01/1973
• Est. Priority Date: 06/21/1971
• Status: Expired due to Term

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Albert E. Schulz, Raymond W. Kunz
• Inventors: Kunz, Raymond W., Schulz, Albert E.
• Primary Examiner(s): Bartis, A.
• Application Number:
  US05/154,778
• Time in Patent Office: 680 Days
• Field of Search: 219/359,360,361,363,364,366-370,374-377,379-382 165/122,121 34/96-99,243 126/11AA,11B
• US Class Current: 392/368
• CPC Class Codes: F24H 9/2071 using electrical energy supply

Abstract

An electric fan heater of the space heating type includes a housing having an air inlet opening in the top wall and an air outlet opening in the front wall with an electric heating element in close proximity thereto. A motor driven axial flow fan having a vertical axis of rotation is utilized to provide an air flow through said housing between said inlet and outlet openings. A temperature responsive safety switch is located above the heating element and is positioned in an air flow passage having one end in air flow communication with the air outlet and its other end in air flow communication with the air outlet and its other end in air flow communication with the inlet side of the fan whereby heated air is allowed to flow back to the fan over the safety switch in the event of an obstruction at the outlet opening. In one embodiment a shielding member is provided between the air inlet opening and the fan to partially block the inlet opening. The shielding member is positioned above the fan adjacent the centrifugal air stream path toward the front wall and overlies the air passage.

Claims

1. An electric fan heater comprising:

a. a housing, said housing having top, bottom, side, rear and front walls, b. an air inlet opening in the top wall of the housing, c. an air outlet opening in the front wall of said housing, d. a motor-driven axial fan within the housing between the inlet and outlet openings, e. a heating element located between the air outlet and fan in close proximity to the air outlet opening, f. a temperature responsive switch for de-energizing the fan heater, said switch positioned above said heating element, g. air passage means between the temperature responsive switch and the inlet side of the fan, one end of said air passage in air flow communication with the inlet side of the fan and the other end in air flow communication with the air outlet and located above the heating element said temperature responsive switch being in the path of air flow through the air passage means, and h. said air inlet opening having a depending circumferential wall extending below the central horizontal plane of the fan propeller and having a cut-out portion to accommodate the air passage means between the temperature responsive switch and the inlet side of the fan.

2. An electric fan heater comprising:

a. a housing, having top, side, rear, bottom and front walls, b. an air inlet opening in the top wall of the housing, c. an air outlet opening in the front wall of the housing, d. a motor-driven axial fan propeller within the housing, said fan having a vertical central axis of rotation to thereby provide a centrifugal air stream path within the housing in the direction of the air outlet opening, e. a heating element in said air stream path between the air outlet and fan propeller and located in close proximity to the air outlet opening, f. a temperature responsive switch for de-energizing the fan heater, said switch positioned above said heating element, g. air passage means between the temperature responsive switch and the inlet side of the fan, One end of said air passage means in air flow communication with the inlet side of the fan and the other end in air flow communication with the air outlet and located above the heating element, said temperature responsive switch being in the path of air flow through the air passage means, and h. a shielding member between the fan propeller and air inlet opening to partially block the air inlet opening, said shielding member being located above the fan propeller adjacent the centrifugal air stream path toward the front wall and covering the air passage.

3. The electric fan heater of claim 2 wherein the air inlet opening has a depending circumferential wall extending below the central horizontal plane of the fan propeller and having a cut-out portion to accommodate the air passage means between the temperature responsive switch and the inlet side of the fan.

4. The electric fan heater of claim 3 wherein the housing is molded from plastic material and the temperature responsive switch is responsive to a temperature below a temperature at which the plastic material will be deformed.

5. The electric fan heater of claim 4 wherein the heating element is wound upon an electrically insulated heater box and the temperature responsive switch is secured to the top of the box to sense excessive temperature rise in the heating element and also deflected heated air from the outlet opening caused by an obstruction at said opening.