PORTABLE HEAT GUN

• US 3,612,824 A
• Filed: 12/03/1969
• Issued: 10/12/1971
• Est. Priority Date: 12/03/1969
• Status: Expired due to Term

• Current Assignee: Robert C. Berryman, Robert R. Townsend
• Original Assignee: Robert C. Berryman, Robert R. Townsend
• Inventors: Berryman, Robert C., Townsend, Robert R.
• Primary Examiner(s): Bartis, A.
• Application Number:
  US04/881,680
• Time in Patent Office: 678 Days
• Field of Search: 219/369,370,373,380,379,364,366,367,368,359,361 34/96-100,243
• US Class Current: 392/383
• CPC Class Codes: F24H 3/0423 hand-held air guns

Abstract

The forward end of a tubular air discharge spout of a portable air blower is encompassed by a tubular collar supported in spaced relation thereto to form an annular channel for flow of ambient cooling air between the collar and spout. A heater tube having a flared aftersection is positioned in registry with the discharge spout to receive air from the channel and spout. The flared end is secured to the forward end of the collar and has a plurality of apertures through which a portion of the air discharges into an annular air passage formed by a tubular shield encompassing the heater tube in concentric spaced relation. The remainder of the air passes through the heater tube and is heated by an electric heater in the tube. The unheated air energizing from the forward end of the annular air passage encompasses the hot air outflow from the heater tube. The volume and temperature of the air discharge is regulated by an adjustable damper on the blower inlet. A switch enables the user to deenergize the heater, thereby affording a controllable airflow at ambient temperature.

Claims

1. A portable heat gun comprising:

a. a frame;

b. an air blower mounted on said frame including a rotor and a casing having an air intake port and a tubular air discharge spout to direct air forwardly in a predetermined direction;

c. a tubular collar mounted on and encompassing the forward end of said tubular spout in spaced relation to define a substantially annular channel for the flow of ambient air therethrough;

d. a forwardly converging frustoconical member mounted on the forward end of said tubular collar and having a plurality of apertures extending through the converging walls of said member in said forward direction;

e. a heater tube mounted on the forward end of said converging member, said tube extending forwardly to a hot air discharge end;

f. electrical heating means mouNted in said heater tube for heating the air entering said tube from said blower discharge spout and said annular channel less the air flowing through said apertures; and

, g. a tubular shield encompassing said heater tube and forming therewith an annular passageway for the flow therethrough of air passing through said apertures and moving forwardly in said predetermined direction to emerge from the open forward end of said passageway in an annular flow pattern encompassing the hot air emitted from said air outflow from said heater tube, the air flow from said discharge spout being effective to induce the flow of ambient air through said annular channel and along the adjacent surface of said apertured frustoconical member, said ambient air flow helping to maintain the temperature of said tubular collar at ambient conditions.

2. A portable heat gun as in claim 1 wherein said tubular shield member is mounted on the after end of said frustoconical member adjacent the forward end of said tubular collar and in thermal contact therewith.

3. A portable heat gun as in claim 2 further including switch means for disconnecting said electrical heating means.