US1976652A - Electric heater - Google Patents

Description

Oct. 9, 1934. Bfi g 1,976,652

ELECTRIC HEATER Original Filed Aug. 27. 1931 2 Sheets-Sheet l Oct. 9, 1934. Q BRANTINGHAM 1,976,652

ELECTRIC HEATER Original Filed Aug. 27, 1931' 2 Sheets- Sheet 2 17 AELHIHIIHHII) llill: fl rlrl it ,23 2'7 Z3 13 Patented Oct. 9, 1934 PATENT ELECTRIC HEATER Alan Brantingham, Rockford, 111., assignor, by mesne assignments, to Faries Manufacturing Company, Decatur, IlL, a corporation of Illinois Application August 27, 1931', Serial No. 559,736

Renewed August 24, 1933 9 Claims. (01. 219--39) This invention relates to electric heaters of the type employing a fan to circulate the air as it is heated, and constructed to permit operating the fan at high speed without the heating unit, for cooling purposes.

One of the objects of my invention is to generally improve the construction and operation of electric heaters of the type described.

Another object is to embody in an electric heater of this type certain units of assembly enabling production at low cost of manufacture and enabling theseparate units to be tested and, if necessary, adjustments to be made before final assembly of said units into the heater as a whole. Another object ofmy invention is to provide a heater and fan which may be operated with safety around children. The fan and heating elements are both completely guarded by casings and grills. The casings of heaters of this type usually become so heated that one is apt to be burned, or at least experience some shock and discomfort, by coming in contact therewith accidentally, and, of course, this makes it necessary to provide handles thereon to permit their being moved about. In my heater, which is also intended for portable use, the interior construction is so designed that during operation the outer casing or shell remains sufficiently cool to eliminate the hazard mentioned, and permit han- 80 dling thereof without the use of unsightly handles.

Another feature of my inventionis the provision of supporting means forre'sistance wires which space them in parallel fashion and apportion equal lengths of resistance wire between the insulators. F

Other objects of the invention which relate more to the detailed construction will be brought out in the description in which reference is made to the accompanying drawings, wherein- .40 Figure 1 is a front elevation of the heater;

Fig. 2 is a vertical section taken on' the line 2-'-2 of Fig. 1; i

Fig. 3 is a section taken on the line3--3 of Fig. l; g i

Fig. 4 is a vertical section taken on the line 4-4 of Fig. 2; and I Fig. 5 is a' vertical section'taken on the line 5 5 of Fig. 2. V

This application is a continuation in part of my application Serial No. 536,334, filed May 11, 1931.

Referring to Fig. 2, 11 indicates the front plate of the heating unit and 12 the back or motor assembly plate. These plates are spaced' apart by a casing or band 13 having legs 14 attached thereto by bolts 15. The front plate 11 has a substantially square opening 16 for the passage of heated air, said opening being covered from the inside with a wire screen or grill 1?. The heating element 18, which is in the form of a crimped ribbon of resistant material, is threaded up and down and spaced evenly over practically the entire opening 16, as clearly shown in Fig. 5. The ends of the ribbon are looped around the insulator spools 19 and welded to the end coils as at 20. The correct spacing is effected by the insulator spools 19 being mounted on supporting plates 21 by means of cotter pins 22. This arrangement of the heating element provides uniform length of ribbons between insulators and in assembling, each coil is given the same tension. This prevents sagging and distortion of the ribbon during operation because all of the ribbons will expand alike. The insulator supporting plates 21 and the wire grill 1'7 are held to the front plate 11 by lock nuts 23 which are threadedly mounted on studs or tie bolts 24 which thread into the front plate at points 25 where thickness of material is provided by the ornamental design of the faceplate. Strips of heat insulating material. 26 are interposed between the insulator supporting plates 21 and the grill 1'! for the purpose of checking the transmission of heat by conduotion from the heating element to the face plate 11 which otherwise might burn or discolor 35 the finish. The insulator supporting plates 21 have inwardly bent flanges 27 which serve as deflectors to direct the air from the fan 28 around the insulators and out the front opening 16, thereby cooling the insulators.

The fan 28 is driven by the motor 29 which is mounted substantially in the center of the back plate as clearly shown in Fig. 4, by bolts 31 entered in a Y-shaped rib 32 integral with the back plate 12. This back plate has openings 33 which 9 are covered by an expanded metal screen or grill 30 interposed between and held in place by the motor 29- and the rib '32. A three position switch 34 is also mounted on the rib 32 beneath the motor. The lead-in wire 35, guarded. by an insulator thimble 36, enters the heater directly beneath the switch.

The split casing or band 13 to which the legs is are attached is joined at the bottom by the bolts 37 entered through the downwardly turned flanges 38. The upper half of the casing is lined on the inside with a heat insulating material 39 to prevent this thin-wall casing from'becoming sufficiently heated to be dangerous.

The motor, switch and wiring plan used in this 110 unit have all been fully disclosed in my copending application, Serial No. 536,334, filed May 11, 1931, and need not be further described other than to say that at one position of the switch the motor and heating element are connected in series, the fan turning only fast enough to carry the heat away from the heating element. At the second position of the switch, no current flows. At the third position the motor operates at high speed, delivering air for the purpose of any ordinary electric fan. In this heating element is disconnected.

The method of assembling the above described parts is as follows: The insulator supporting plates 21 with the insulator spools 19 attached,

position the the front plate 11, the grill 17, and the heat insulator strips 26 are assembled as one unit and held together by the stud bolts 24 and nuts 23.

The resistance ribbon 18 is then threaded in place,

the ends doubled back and welded, leaving sufficient. length of ribbon at the ends to be connected to wires. The heating unit being complete may be tested atthis stage of assembly.

The motor 29 together with the switch 34 and the grill 30 are assembled on the back plate 12. All the necessary wire connections may now be made with exception of the two heater coil lead wires 41 and 42. This unit is now complete and may be tested. After this the lead wires 41 and 42 may be fastened to the ends of the resistance ribbon 18 by means of the bolts 43, this preferably being done during final assembly of they heater units. The studs 24 projecting rearwardly from the front plate 11 are passed through holes in the back plate 12 and nuts 44 are placed loosely thereon. The casing or band 13 with the legs afiixed thereto is then spread sufficiently to encircle the front and back plate and when drawn together at the bottom and held with bolts 37, said band seats in recessed annular shoulders 45 and 46 in front and back plates 11 and 12, respectively. The nuts 44 are then tightened, drawing the front and back plates tight to the casing 13 which also serves as a spacing collar. From the foregoing it will be seen that I have provided an electric heater made up principally of three units of assembly, one which may be termed a front plate unit of assembly comprising a front plate and the heating unit parts held in operative relation by means of tie bolts, anothera back plate unit comprising a back plateand an electric motor and fan mounted thereon, and a thirda casing unit comprising a band encircling the parts carried between the front and back plate units, said tie bolts serving to hold the front and back plate units together in position on the casing unit. In the preferred embodiment of my invention herein disclosed, the back plate unit is drawn into position by means of nuts on the tie bolts, although it will be understoodthat in practice, equivalent means might be used for this purpose. Another feature in connection with the preferred embodiment is the provision of legs mounted directly on the casing unit for the pur-' pose of supporting the heater as a whole. Another feature is the construction and arrangement of the insulator supporting plates and theuse of these plates as deflectors for directing the air blast past the insulator supports for cooling them. These and other features described inthe foregoing specification make for simplicity in design and construction and are factors both in the low cost of manufacture of the parts, as well as in the low cost of assembling such parts. Further? more, a heater'embodylng the features herein disclosed may be produced in an attractive ornamental design and be so constructed that it will serve very efiiciently the purposes of heating or of cooling as the case may require.

It is believed the foregoing description conveys a good understanding of all the objects and advantages of my invention. The appended claims have been drawn with a View of covering all legitimate modifications and adaptations.

I. claim:

1. In a motor driven fan, in combination, a heating unit, a front plate on which said heating unit is mounted, a back plate, a motor driven fan mounted on said back plate, the heating unit being completely assembled on the front plate and the fan being completely assembled on the back plate, said plates having openings to permit passage of'air moved by said fan, a casing encircling the front and back plates and serving only to hold them in spaced relation, means for drawing the front and back plate toward each other, whereby to clamp the casing therebetween so as to form a rigid unit, and means for supporting said casing so as to support the rest of the unit thereby. v

2. In an electric heater, in combination, a front plate having an opening for the passage of heated air, an open-work grill covering said opening, insulators, supports to which said insulators-are attached, resistance wires strung upon and between said insulators, heat insulating material between said grill and insulator supports, and means serving to fasten both the grill and the insulator supports to the front plate. $3. In an electric heater, in'combination, a motor driven fan, a front plate having a substantiallyrectangular opening provided thereinfor the passage of an air blast from said fan, a pair of insulator supports mounted on said front plate parallel to each other on opposite. sides of said opening, insulators attached to said insulator supports, resistance-wires strung between said insulators, the length of the resistance wires between insulators being substantially equal and traversingsubstantially the entire area of said opening in the front plate.

' 4. In an electric heater, in combination, a motor driven fan, a front plate having an opening for the passage of an air blast from said fan, a pair of insulator supports mounted on said front plate parallel to each other on opposite sides ,of'

said opening, insulators mounted on said insulator supports, resistance wires strung on said insulators, said insulator supports having flanges to direct and converge the air stream from said fan into the area traversed by the insulators.

5. In an electric heater, in combination, a front plate assembly comprising a. front plate having a central opening, a grill covering said opening and positioned against the plate, insulator supports positioned against and insulated from the grill and equipped with insulator spools; tie bolts fastened tothe front plate and serving to hold the grill and insulator plates in position, and resistance ribbon strung back and forth onsaid insulator spools; a back plate unitcomprising a back plate having a central opening for the passage of air, a grill covering said opening and an electric motor and fan mounted on the back plate, the back plate unit being adapted to be held in position on the tie bolts of the front plate unit; and a casing unit comprising a band adapted to be interposed between the front and back plate units and to encircle the structure carried there: byfand to hold said plates in spaced relation,

said units being clamped to the band and in fixed relationship by means of nuts on said tie bolts.

6. In an electric heater, in combination, a front plate unit of assembly comprising a front plate having an opening for the passage of air, a plurality of insulator supporting plates each equipped with a series of insulator spools, tie bolts serving to fasten said insulator supporting plates to the frontplate, and a resistance ribbon strung back and forth on said insulator spools; a back plate unit of assembly comprising a. back plate and an electric motor and fan mounted thereon, the back plate adapted to be mounted on said tie bolts; and a casing unit adapted to be interposed between and upon said'front and back plates for holding them in spaced relation; and means on the tie bolts holding said units in position.

7. In an electric heater, in combination, a front plate having a central opening for the passage of air, a plurality of insulator supporting plates mounted on the inner side of said front plate and each equipped with a series of insulator spools, a resistance ribbon strung back and forth on said insulator supports, and an electric motor and fan for producing a blast of air past the heater formed by said resistance ribbon, said supporting plates having deflector flanges extending in the path of the air blast and serving to deflect and converge the air blast inwardly past the insulators through the opening in the front plate.

8. In an electric heater, in combination, a front plate having a central opening for the passage of air, insulator spools carrying resistance ribbon constituting the heating element, means supporting the insulator spools comprising a supporting plate structure having a deflector arranged to direct an air blast from an electric motor fan past the insulator spools and through the heating unit and the opening in the front plate, and an electric motor and fan for producing said air blast.

9. In an electric heater, in combination, a front plate unit of assembly comprising a front plate having an opening for the passage of air, and an electric resistance element traversed across said opening; a back plate unit of assembly comprising a back plate and an electric motor and fan mounted on the back plate; a casing unit comprising a longitudinally split band interposed between and encircling the structure of said front and back plate units and adapted to be seated on shoulders provided on said units and to hold them in spaced relation, said casing unit being equipped with legs serving to support the entire heater; means for drawing the front and back plate units toward each other to clamp the interposed casing unit therebetween, and means for contracting the split band forming the casing unit, whereby to firmly engage the shoulders on the front and back plates.

. ALAN BRANTINGHAM.

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