US863454A - Electric heating element. - Google Patents

Description

No. 863,454. PATENTED'AUG. 13, 1907. G. J. SCHNEIDER.

ELECTRIC HEATING ELEMENT. APPLICATION FILED JULY 9, 1906.,

2 SHEETS-SHEET 1.

fyweaLc'u-r G'aooe efe a/wweader PATENTED AUG. 13, 1907.

2 SHEETS-SHEET 2.

aid er,

wax/sue UNITED STATES GEORGE .l'. SCHNEIDER, OF DETROIT, MICHIGAN, ASSIGNOR T AMERICAN ELECTRICAL HEATER COMPANY, OF DETROIT, MICHIGAN, A CGRPO lriiION Oh MICHIGAN.

ELECTRIC @ACEING FILED KENT. I

Specification of Letters Patent.

Fatented Aug. 13, 1907.

Application and July 9. 1906. Serial no. 325,295.

"To all whom it. may coricerm Be it known that I, Gnoasr. J. SCHNEIDER, 'a citizen 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 Electric Heating Elements, of which the following is a specification, reference being had therein to the accompanying drawings. 1

It is the object of the invention to obtain a construction' of an electric heating element, in which the heat generated in the resistance is conducted away rapidly and uniformly from all portions thereof, and is distributed in a body of considerably greater mass. This, on the one hand, prevents the destruction of the element through the over heating of a portion of the resistanceand on the other hand facilitates the application of the heat to the point desired, it being either conducted or radiated from the body in which it is first distributed.--

To this end, the invention consists in the construction as hereinafter set forth.

In the drawings, Figure l is a plan; Fig. 2 is an end elevation of the heating element; Fig. 3 is an elevation of the several members constituting the heating unit detached; Fig. 4 is a longitudinal section of said members assembled but unclaniped; Fig. 5 is a section elevation of Fig. 4; and Fig. 6 illustrates a slightly modified construction.

Electrical heaters designed foruse with the commercial electrical currents ordinarily available are necessarily of comparatively high resistance. In order to obtain the proper resistance in a small space, the cross section of the conductor is limited, and as a consequence a very slight cause is sufiicient to break the circuit; for instance, if some portion of the conductor is in less perfect heat conducting contact with the in sulator covering, the heat generated at this point will accumulate, and so cause a burn out. With the present invention this diiiiculty is avoided, by placing all portions of the resistance in heat conducting proximity to a body of sufficient mass to act as an equalizer. Furthermore, a comparatively high resistance is obtained by using a conductor offering a. tortuous course for the current in adjacencc to the said heat absorbing body.

As illustrated in Figs. 1 and 2, A are heating units, and l? are heat absorbing elements, which are arranged alternately in series. The heating units A are formed of electrical conductors arranged to pass the current back and forth, or through a trirtuous course, and this conductor is insulated from the adjacent heat absorbing bodies by thin plates of suitable material, such-as mica.

To obtain the necessary resistance, I preferably form the conductor of very thin metallic plates or metal foil, and arrange a series of these plates in parallel planes separated from each other merely by a thin stripof mica. Thus the thickness of the combined plates and insulators in the scries is so limited that the heat generated in the resistance may readily pass by conduction into the adjacent heat absorbing body B.

To further increase the resistance, I preferably slit the conductor platcs so as to cause the current to pass back and forth through a path of much greater length than the major dimension oi the plate. This, as illustrated in Fig. 3, may be accomplished by forming slits a and b extending alternately from opposite edges of the metallic plates 0 and diminishing the cross section of the conductor, through which the current passes. A series of these plates is then formed with intervening mica insulator plates (1, which are arranged to permit the adjacent metallic plates to come into contact alternately at opposite ends. The series is then clamped by suitable means, such asthc bolts 0, which pass through alincd apertures in the conductor plates, insulators, and the heat absorbing bodies B, and exert a tension combining all of the parts together.

Danger of short circuiting through the clamping bolts 0 is avoided by covering said bolts with an insulator sleeve D, and to avoid the possibility of turning the edges of one of the conductors across the intervening insulator, P preferably employ the construction illustrated in Fig. 3. In this the metallic plates upon opposite sides of the insulator are provided with polygonal apertures for the bolts, and these apertures are shaped to be out of exact registration although concentric with each other. Thus the portions of one of the metallic plates which are in contact with and are centered by the bolts 0, are arranged opposite spaces a in the adjacent metallic plate, and therefore if the conducting edge of one of the metallic plates is drawn across the intervening insulator, it will not short circuit with the adjacent plate.

When clamping pressure is applied to the series, the

exposed ends f of the metallic plates will be pressed into contact with cacinother or the adjacent body B, and in this manner a continuous circuit is established, not only through the series of plates constituting a unit, but also the series of alternate units and heat absorbing elements B. Thus the resistance oi the entire circuit may be made as high as desired.

In operation, the heat generated in all portions oi the conductor finds an easy path of escape through the thin insulator strips into the bodies 13, and from the latter is distributed by conduction or radiation. The clamping pressure issuiiicicnt to prevent the formation of air spaces adjacent to any portion of the conductor, so that the distribution of heat therefrom to the bodies B is by conduction and not radiation. Thus the over heating of this part of the circuit is prevented.

.sulators, means passing through said plates for clamping What I claim as my invention is:

-1. An electrical heating unit comprising a series of alternately arranged laminated conductors and insulators. the opposite ends (if-adjacent insulators being cut away for permitting direct contact of alternate pairs of adjacent conductors at opposite ends whereby :1 continuous cult is formed through the series, and means for clamping the series 'to-hring all portions thereof in mechanical contact.

2. An electrical heating nit comprising a series of alternately arranged laminated conductors and insulators. a clamping rod passing through zilined apertures in said plates. the apertures in adjacent conducting plates, being out of exact registration to prevent short circuiting there lit-tween.

3. An electrical heating element comprising a series of alternately arranged thin flat conducting plates and inthe series to press the members thereof into close contact, and means for preventing said plates from contacting with each other adjacent tosaid clamping means.

4. An electrical heating element comprising- :1 series of alternately arranged thin lint conductingplntes and insnlators, said conducting plates being slit to cause the current to pass tortuously lherethrougl'i, and bolts passing clnselyihrough said insulators and loosely through said plates for clamping the series to press said plates into close contact with each other.

An electrical heating element comprising a series of alternately arranged metallic i'oil conducting plates and thin fiat insulators the alternate insulators being shortened at opposite ends to permit the contacting of the ad jacent conducting plates alternately at opposite ends to form a continuous circuit through the series, and means for clamping the series to press close contact.

(S. An electrical heating element comprising a series of alternately arranged resistance elements and heat distribut rs and each resistance element comprising a series of alternately arranged thin conducting plates and insulator plates, said conducting plates lacing folded over and connected at opposite ends to form a continuous circuit through the series of the unit, and said units being e1ectrically connected through the intermediate heat distribliters.

T. An electrical heating element comprising a, series oi alternately arranged resistance elements and heat dis- 'trihuiers each resistance element comprising a series of alternately arranged thin fiat conducting plates and insulntors, an insulated rot". passing through alineil open tures in the members of the series for clamping the same in close mechanical contact, nndmeans for preventing the contact of said plates with each other adjacent to said rod.

S An electrical heating element comprising a series of alternately arranged resistance elements and heat disiribut'ers, each resistance element comprising a series of alternately arranged conducting plates and insulator plates, adj: -ent conducting plates being alternately con nected at opposite ends toform a continuous circuit through filic series, and adjacent series electrically connected to opposite ends of the intermediate heat distributer.

In testimony whereof I afiix my signature in presence of two witnesses.

the adjacent plates into uriulilllfl J, SCHNEIDER. Witnesses AMELIA WILLIAMS,

NnLLin KINSELLA.

Images