US1222001A - Electrical heating unit. - Google Patents

Description

R. KUHN & A. OAKES.

ELECTRICAL HEATING UNIT.

APPLICATION men JULY 9. 1914.

1,222,001 Patented Apr. 10, 1917.

0 0000000000 J, E,- 0000000000 l n e Z I 0000000000 51 if Q" I I I 1 $151M)? Him WITNESSES: IN VEIV TORS A 56/5 A&% 72 3Q ZrcZ 2 61165 A TTORNEKS iii UNITED STATES PATENT OFFICE- BOBERT KUHN AND ARCHIE CAKES, OF DETROIT, MICHIGAN, ASSIGNORS TO FRANK KUHN, 0F DETROIT, MICHIGAN.

ELECTRICAL HEATING UNIT.

Specification of Letters Patent.

Patented Apr. 10, 1917.

Application filed July 9, 1914. Serial No. 849,939.

To all whom it may concern:

Be it known that we, ROBERT KUHN and Aroma OAnEs, citizens of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan,- have invented certain new and useful Improvements in Electrical Heating Units, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to electrical heating units and more particularly to a construction which may be used in small electrically heated instruments such as curling iron heaters. It is the object of the invention to obtain a resistor of relatively high resistance. occupying comparatively small space, and further to so mount said resistor in a casing that the developed heat may be eliiciently used.

In the drawings:

Figure 1 is a longitudinal section;

Fig. 2 is a sectional plan View;

Fig. 3 is a cross section; and

Fig. 4 is an enlarged cross section through the reinforced insulator.

A is a suitable casing, preferably formed of sheet metal and provided with a base section 13, an inverted U-shaped section mounted thereon and sections 1) upon opposite sides 'of the section C for completing a rectangular housing. The side and top walls of this housing are apertured as indicated at D to permit the passage of air therethrough.

The electrical heating unit is mounted within the casing it and distributes its heat by radiation tothe curling iron or other instrument which may be laid on the top wall of said casing. As the amount of heat required is comparatively small it is necessary to have a resistor of relatively high resist ance and it is desirable to distribute the heat unifor-ml therefrom. This efiect is secured by forming the heating unit of an insulator strip preferably of mica, having rounded notches i distributed along its opposite sides. The resistor G is formed of a coil of wire which is looped baclr and forth over the insulator E and through the notches F, as shown in Fig. 2. This arrangement exposes practically the entire radiating surface upon the upper side of the insulator E, where the heat generated will be effective. At the same time the resistor is inclosed within the housing, which, having apertures at its side and top, will permit the free circulation of air, thereby preventing any dangerous rise in temperature should the current be left on when the instrument is not in use.

The ends of the resistor G are secured to clamping terminals H and I at opposite ends of the memberE, and a return connection J on one of said terminals preferably extends to the opposite end of the strip and to a terminal post K thereof, so that the flexible conductor L may enter one end of the in strument and be attached to both terminals. The unit is preferably mounted upon U- shaped standards M which rise from the base within the space housed by the members C and D.

To impart the necessary mechanical strength and rigidity to the strip E a metallic reinforcement N of lesser width than the strip is attached to the underside thereof and extends longitudinally. This reinforcement may be attached by suitable means such as rivets O which are raised to avoid direct contact with the resistor. The reinforcement may also be further strengthened by being provided with downturned flanges P upon opposite edges thereof. Thus arcing of the insulator strip is prevented, and by reason of the fact that the reinforcement is of lesser width than the insulator strip there will be no danger of short cirouiting the resistor.

What we claim as our invention is:-

1. An electrical heater comprising an insulator strip having notched opposite edges, a metallic reinforcement secured to said strip and extending longitudinally on one side thereof, and a resistor looped back and forth across the opposite side of said strip from the reinforcement with the bends of the loops engaging said notches and ex tending beneath the portions intermediate the same.

2. An electrical heater comprising an insulator strip having a metallic reinforce-- ment of lesser width extending longitudinally on one side thereof, the opposite edges of said strip being notched, and a resistor looped back and forth upon the opposite side of said strip from the reinforcement with the bends of the loops extending through said notches and beneath the' portions intermediate the same.

3. An electrical heater comprising an insulator strip having notched opposite edges, a metallic reinforcement of lesser Width secured to said strip and extending longitudinally and centrally on one side thereof, and a resistor formed of a continuous coil looped back and forth across the opposite side of said strip from the reinforcement With the bends of the loops passing through said notches and beneath the ends of the portions intermediate the same.

4. An electrical heater comprising an insulator strip having notched opposite edges, a metallic reinforcement of lesser Width extending centrally and longitudinally of said strip on one side thereof, a resistor formed of a continuous coil looped back and forth across the other side of said strip from the reinforcement With the bends of the loops passing through said notches, terminals connected to one end of said strip. and a returncient distance to avoid contact With the re 7 sistor.

In testimony whereof We affix our signatures in presence of two Witnesses.

RUBERT KUHN. ARCHIE UAKES. Witnesses:

HARRY W. LUYOKX, STANLEY B. OAKns.

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