US1573787A - Electric heater - Google Patents

Description

Feb. 16 1926. 1,573,787

c. P. RANDOLPH ELCTRIC HEATER Filed May 25, 1925 m vm., f

Inve r orLe P. rwcLoLph HLS Attorney i Patented Feb. 16, 1926.

A. UNITED STATES y 1,573,787 PATENT OFFICE.

CHARLES P. RANDOLPH, OF OAK PARK, ILLINOIS, ASSIGNOR TO EDISON ELECTRIC .APPLIANCE COMPANY, INCORPORATED, 0F CHICAGO, ILLINOIS, A. CORPORATION OF NEW YORK.

ELECTRIC HEATER.

Application led lay 25, 1925. Serial Hol 32,529.

To all whom it may concern.'

Be it known that I, CHARLES I. RAN- 'noLr1I,`a citizen of the United States, residing at Oak Park, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Electric Heaters, of which the following is a specification.

My invention relates to electric heaters, more particularly to electric Hatirons. and has for its object the provision of'a Asimple and reliable device of this character which may be manufactured at low cost.

. Incarrying out my invention I Secure an insulating heating 'resistance conductor in a groove inthe top of the body to be heated.

For a more complete understanding of my invention reference should be. had to the accompanying'drawing in which Fig. 1 is a sectional view,l of an 'electric atiron em.- bodying my invention while Fig. 2 is a plan view with the cover and various other arts removed showing the arrangement o the heating unit.

Referring to the'drawing, in the form of my invention disclosed I have show n a mass of heat conducting material 10, such as cast iron, forming a atiron bodyof conventional outline and being provided on its lower side with'an .ironing face 11. The flatiron body 1() is provided at the'top with a central upwardly projecting portion 12 having substantially the same outline as the lower portion whereby a ledge 13 is formed around the atiron body on which rests a suitable cover 14. The cover is secured to the {iatiron body by means of screws 15 and 16./

These screws also ass .through and secure a suitable handle 1 The cover 14 iscentrally located on the atiron body by means ofY stops or projections 18 to 22 inclusive spaced along-the sides of the raised portlon 12.`

In the upper surface of the raised portion 12 a groove 23 is provided, having substanuconstructed substantially in accordance with torv 26 embedded in powdered electrically insulating material 27. The sheath 25 is preferably formed of seamless tubing. The powdered insulating material is compacted to a hard dense mass by reducing the diameter of the sheath, for example, by rolling or swaging, and forms an excellent insu ator and also an eliicient conductor yo heat fromcthe resistance conductor to the sheath. In the arrangement shown the sheath is shaped with a substantially Square cross section and is of such size asitolit quite closely in the groove 23.

A clamping plate is provided having its edge bent downward so as toform a ridge 29, which rests on the heating unit 24. This clamping plate is Secured to the body 10 by means of screws 30, and the heating Vunit is thereby clamped firmly in the groove. It will be observed that the lower fiat side of the heating unit is pressed firmly against the flat bottom of the groove and is thus maintained in good thermal relation therewith. The sides of the groove are inclose proximity to the heating unit and receive a certain amount of heat by radiation and conduction. The flatiron body 10 is preferably cast, the groove 23 being formed in it u pon casting. The only machine Work necessary, therefore, is that required -to finish the ironing face 11. f

The resistance conductor 26 has its ends connected to terminal members 31 and 32 which in turn are connected to contact pins 33 carried by the cover 14. A. suitable guard34: surrounds the contact pins. An electrical connection is established between a suitable supply circuit andthe contact pins by means of an attachment plug of any well known form.

It will be observed that my invention lends itself to a simple and rugged low cost construction throughout the device. The heating unit, which is the most prolific source of trouble in electric. appliances, is`

of particularly rugged construction: The .arrangement of the heating unit w1th re spect to the heated body the eiiicicnt conduction of heat fromY the resistance con- 1,367,341 -to Abbott 'dated ductor to the heated b0dy, facilitates the production of the heated body at low cost, and promotes ease and quickness of .assembly. Furthermore, the heating unit can be removed very easily at any time for repairs or renewal.

While I have described my invention as embodied in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that I do not limit my in- .vention thereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of my invention, the` scope of which is set forth in the annexed claims.

lVhat I claim as new and desire 'to secure by Letters Patent of the United States, is

l. The combination with a mass of heat conducting material provided with a substantially flat-bottom groove, of a heating unit encased in a continuous unbroken metallic shea-th clamped in said groove, said sheath being formed with a substantially flat surface held in engagement with the bottom of said groove in good thermal relation therewith. y

2. The combination with a mass of heat conducting material provided with a flatbottom groove having a depth substantially equalto its width, a resistance conductor encased in a continuous unbroken metallic sheath shaped to have a substantially square cross section fitting closely in said groove, and means for clamping said sheath in said groove so that one side thereof is held in intimate thermal relation with the bottom of said groove.

3. The combination with amass of heat conducting material provided with a flatbottom groove having a depth substantially equal to its width, a helical resistance conductor, a sheath of seamless metal tubing surrounding said resistance conductor, powdered heat refractory insulating material in said sheath compacted to a hard dense mass around said resistance conductor by reducing the diameter of said sheath, said sheath being shaped during the reducing operation to have a substantially square cross section fitting closely in said groove, and means for clamping said sheath 1n said groove so that oney side thereof is held in intimate thermal relation with the bottom of said groove.

In Witness whereof, I have hereunto setV my hand this 21st day of May, 1925.

CHARLES P. RANDOLPH.

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