US1494939A - Electric heater - Google Patents

Description

May 20, 1924. 1,494,939

c. c. ABBo'r-r ELECTRIC HEATER Filed Sept. 23, 1922! Iwentcr; Charles- C.^bbott,

by MMX His At orn'ey.

Patented vmy 2o, 1924. i

UNITED STATES PATENT oFFlcE.

CHARLES C. ABBOTT, OF PITTBFIELD, HASSACHUSETTS, ASSIGNOB T0 GENERAL ELECTRIC COIPANY, A CORPORATION OF NEW YORK.

ELECTRIC mman.

`Application tiled September 23, 1922. Serial No. 590,020.

To all whom it 'may concern.'

. 'Be it known thatl I, CHARLES C. Annorr'r, a citizen of the United States, residin at Pittsfield, in 4the county of Berkshire, tate of.Massachusetts, have. invented certain new and useful Improvements in Electric If'leaters, of which the following is a specification.

My invention relates to electric heaters and has for its object the provision of a sim le, rugged and compact electric heater.

y invention has utility in various heating applications, for example, it may be used as an air or space heater or 1t may be clamped on or otherwise secured to an object to be heated. v

In carrying out my inventlon I employ a sheath Wire heating unit, for example, of the type forming the subject matter of my copending application Serial No: 549,63t3, filed April 4, 1922. In heating units o'this type the resistance conductor is embedded 1n a compacted mass of insulating material enclosed in a metallic containing sheath. In one form of my invention I provide longitudinal heat dissipating vanes associated with the containing sheath whereb the heat generated in the unit may be quic l transferred either to the air or to the o ject to be heated.

For a better understanding of myinvention reference should be had to the accompanying drawing iii-which Fig. 1 is an elevation View of an electric heater embodying my invention; Fig. 2 is a section vievs7 along the line 2-2 of Fig. 1 looking in the direction of the arrows; Fig. 3 is a view of a modified form of my invention; Fig. 4 is an elevation View of Fig. 3 5 While Fig. 5 is a section view along the line 5 5 of Fig. 4 looking in the direction of the arrows.

Referring to Figs. 1 and 2 of the drawing, the electric heater 10 in one form of my invention comprises a helical coil sheath wire heating unit 11, such as that forming the subject matter o my aforesaid copending application. This heating unit in general comprises a helical resistance conductor 12 embedded in a compacted mass of insulating material 13, such as magnesium oxide, the whole being enclosed by a metallic containing sheath 14. This insulating material not only serves to insulate the resistance l conductor but acts also as a good heat conductor between the resistance con- .tendin ductor and the sheath. Connected to the ends of the resistance conductor are the terminals 11l and 11b which project from the ends of the sheath in insulated relation therewith. The heating unit 11 is clamped between two metallic plates 15 and 16 exlongitudinally thereof, the plates being ormed with registering central longitudinal grooves or recesses 15 and 16 respectively in which the heatin unit is secured. These plates are'welde together as near the heating unit as ssible so as to clamp the heat-ing unittigliitly. The welding of the plates may be accomplished in any suitable manner such as by the line welding or spot welding-process.

The pla- tes 15 and 16 extend throughout substantially the full length of the heating unit 11 and it will be observed form two longitudinal heat, dissipating vanes 17 and 18 extending along opposite sides of the heating unit. Due to the fact that the plates 15 and 16 are clampedtightly on the metallic enclosing sheath 14, an intimate thermal relation is secured between the heating unit and the heat dissipating vanes so that heat generated in the unit will be quickly transmitted to the vanes. This heater is particularly adapted for use as an air or space heater in which application it may be mounted with the vanes 17 and 18 in a vertical position so as to facilitate the circulation of air around the vanes. Apertures 19 may be provided in the vanes 17 and 18 by means of which the heater can be secured to a suitable support, for example, by screws or bolts. The heater may also be similarly secured or clamped on to an object so as to heat the object, the object serving as the support for the heater.

In the modified form of my invention shown in Figs. 3, 4 and 5 one of the clamping plates, for example, 16, is in the shape of a channel member, it being fiat, and having its longitudinal edges bent over to provide for greater strength in a lateral direction. In this form of my invention only one longitudinal recess for the heating unit is provided, this recess 15 being formed in the plate 15 and having a depth substantially equal to the diameter of the heating l to the object so as to be in good thermal relation therewith. The ends; of the heating unit carrying the terminals are preferably' bent away from the plane of the outer face or clamping surface of plate 16 so as to be ont of the way when the heater is secured to the object to be heated, and also to faveilitate the connection of the terminals to a suitable electrical supply source. The heater may be secured` ,by suitable bolts or screws passing through the apertures 19. Obviously this forml of lmy invention can be used also as a space or air heater as described in connection with Figs. 1 and 2.

I have thus provided an exceedingly compact, rugged and economical heater which has many applications and whichis particularly adapted for use as a space or air heater or as a heater for various objects by clamping it onto the object. The construction and arrangement'of the heater offers considerable economy7 in manufacture, sol

that it can be-produced at relatively low.

cost. Also by providing longitudinal rather than circumferential heat dissipating vanes so that the heater is flat, the heater occupies and hence may be fitted in a very limited space.

Since one of the characteristics of heating units of the sheath wire type, such as used for the heating unit 11, is that they can be bent or shaped into any desired form, obviously the electric Aheaters embodying my present invention may be readily formed into any desired shape so as to fit the space or object to be heated.

While I have described my invention as embodied Ln 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 invention 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 setr forth in the annexed claims.

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

1. An electric heater comprising a metallic sheath, a which said s eath is clamped in good heat conducting relation therewith, said plates forming heat dissipating vanes for said sheath, a resistance conductor in said sheath, and granular insulating material embedding said resistance conductor so that heat is readily conducted to said sheathl and heat dissipating vanes.

2. An electric heater comprising a metallic sheath, a pair ofmetallic plates one of which is provided with a longitudinal recess in which said metallic sheath is clamped by the other in good heat conducting relation with said plates, said plates being joined together so as to form longitudinal heat dissipating vanes for said sheath, a helical resistance conductor in said sheath, and

Agranular insulating material compacted to a'hard dense mass in said sheath so that heat is readily conducted to said sheath and heat dissipating vanes.

l3. An electric heater comprising a metallic sheath, a metallic plate provided with a longitudinal groove for said sheath, a second plate forming a clamping surface securing said sheath in said groove in good heat conducting relation with said plates, said plates being connected together so as to form longitudinal heat dissipating vanes for said sheath, a helical resistance conductor in said sheath, and granular insulating material compacted to a hard dense mass in said sheath so that heat is readily conducted to said sheath and heat dissipating vanes.

In witness whereof, I have hereunto set my hand lthis 16th day of September, 1922.

CHARLES C. ABBOTT.-

pair of metallic plates between

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