US761205A - Electrical heating apparatus. - Google Patents

Description

No. 761,205. PATENTED MAY 3l, 1904. C. E. CARPENTER. ELECTRICAL HEATING APPARATUS.

APPLICATION FILED JAN. 27. 1904. N0 MODEL` 2 SHEETS-SHEET I.

LA f @A No. 761,205. PATENTED MAY` 31, 1904.

l G. E. G PBNTER.

ELECTRICAL v ING APPARATUS.

APPLIOAT D JAN. 27. 1904.

N0 MODEL. 2 SHEETS-SHEET 2.

ff le Patented May 31, 1904;

UNITED STATES PATENT OFFICE.

I CHARLES E. CARPENTER, OF NEVITV YORK, N. Y., ASSIGNOR TO CUTLER HAMMER `MANUFACTURING COMPANY, A CORPORATION OF WIS- CONSIN.

ELECTRICAL HEATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 761,205, dated May 31, 1904.

Application filed. January 27, 1904. Serial No. 190,786. (No model.)

T0 all whom it may concern:

Be it known that I, CHAnLns E. CARPENTER, a citizen of the United States, and a resident of New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Electrical Heating Apparatus, of which the following is a specification, reference being had to the accompanying drawings, which form a part hereof.

My invention relates to certain new and useful improvements in that class of apparatus in which the resistance or conductor is heated by the passage of an electric current and in which the heat is transmitted largely by conduction to an outer or surrounding shell, plate,or body, which is in close mechanical relation to, but electrically insulated from, the resistance or conductor by suitable ireproof insulating material.

The object of my invention is to improve the construction of the apparatus generally, to make it simpler and more economical, to provide a very intimate mechanical contact between the conductor and the insulating material and between the insulating material and the plates or exterior shell of the apparatus, while at the same time thoroughly insulating the conductor from the plates, to hold the conductor and the insulating material rmly in place and to prevent their being broken or cracked or distorted, and to simplify the method y'of manufacture.

Another object of my invention is to incase or perfectly seal the resistance or conductor in a fireproof vitreous material and also to place the same with reference to the plate or plates to be heated, so as to provide for the rapid conduction of heat through the insulation to the said plate or plates.

Another object is to protect the conductor or resistance mechanically, so that excessive iow of current through the same, such as would be produced by the overloads incurred incommercial service, shall not dislodge, fuse, or distort the resistance or conductor. v

My invention alsoconsists in the combination, in an electrical heating apparatus, of the plates to be heated in the completed article, a vitreous insulating material between the said plates pressed between them when heated, so as to conform accurately to the shape of the plates and to be in intimate mechanical contact therewith, and an electrical resistance sealed within the insulating material.

My invention also consists in making thel insulating material of a thin layer of vitreous materialand in making it incase and protect the resistance, while at the same time insulating it from the plates, the insulating material being pressed between the plates while in a molten or hot state, so that it entirely fills the space between said plates, and being lcooled in said position in contact with said plates.

My invention also consists in so shaping the plates as to make them adapted to form a mold in which 0r between the parts of which the insulating material is pressed into shape, the insulating material being cooled in said mold under pressure and having as a result of this an intimate mechanical contact with the conductor or resistance as well as with the plates and being held firmly in place lagainst distortion or breakage.

My invention also consists in certain other features and combinations of parts hereinafter described and claimed.

My improved method is illustrated and my improved apparatus shown in the accompanying drawings, in which- Figures 1 to I illustrateone form of my improved method of making such apparatus, Figli showing the completed apparatus thus produced. Figs' to 8 show a modification of my improved method and apparatus. Figs. 9 and 10 show further modifications.

Referring to Figs. l to 4, l is a metal support or plate, preferably a sheet of cast-iron. Atop or plan view of this plate is shown in Fig. l, and Figs. 2, 3, and 4 show sectional views of the same` on the line X X of Fig. 1. The plate l is provided with a recess, as shown, adapted to receive a sheet of ordinary windowglass 2. This sheet of ordinary window-glass is placed in the recess of plate l, and then a resistance wire or conductor 3, preferably of the refieXed type, is laid over the surface of the sheet of glass 2, as illustrated in Fig'. l. A second sheet or layer of glass 4L is then placed on top of the conductor 3, as illustrated in Fig. 3, and then another metal plate Y5 isl placed on top of the sheet of glass 4, as shown in said figure. 6 represents screws or other fastening devices placed at the corners or in any suitable position and are adapted to screw into threaded holes 7 in the lower plate l. By means of these screws the upper and lower plates are fastened or bound together, and thus the parts of the device are held firmly in place. The apparatus is then substantially in the condition shown in Fig. 3. In this condition the parts are then submitted to a high temperature sufiicient to bring the glass to a molten or soft condition, and when in this condition the plates l and 5 are forced together` by any suitable means, thus pressing the sheets of g'lass around the conductor 3 and causing the two layers of glass to unite and incase the interposed conductor. The glass fills up the space between the plates and between the different parts of the conductor and forms a thin homogeneous compact and solid layer of insulating' material, holding' the conductor in place while 'insulating it from both plates and at the same time making intimate mechanical contact with both the conductor and themetal plates. The device is then cooled in this condition, and while being cooled the screws or other fastening's are tightened, so as to hold the parts firmly together and maintain the intimate contact. The apparatus is then as shown in Fig. L

Amodification of my invention is illustrated in Figs. 5 to 8, in which Fig. 5 is a top or plan l view of the device with the upper metal plate and the upper glass plate removed, and Figs. G, 7, and 8 are cross-sections on the line e fr of Fig. 5. In the method which is illustrated in these figures al third or interior sheet of glass 8 is employed, as clearly shown in Fig. 6, around which the resistance 3 is wound. The lower plate 1 is made in the same form as already explained, and a sheet of ordinary window-glass 2 is placed in the recess in said plate. The resistance-wire 3 is wound around the glass plate 8 and is then placed in position, as shown in Fig'. 6. Then the upper sheet of glass is laid on top of the resistance and the upper metal plate placed on top of this and the parts secured together by means of fastenings, as represented in Fig. 7. The apparatus in this condition is then submitted to a temperature suflicient to soften the sheets of glass, and the metal plates are pressed together while the glass is in this condition, as a result of' which the glass is compressed around the resistance so as to fill up completely the space between the metal plates and so as to form an apparatus such as is illustrated in Fig. 8.

In Fig. 9 I have illustrated another modification of my invention in which a sheet of' mica 9 or similar material is interposed between the vitreous insulating material and cach of the metal plates. This docs not materially affect the intimate mechanical contact between the insulating material and the plates, and if in any waythe resistance-wire 3 should be displaced at any point in the insulating material, so as to lie close to the metal plate, the sheet of mica would still serve to insulate the resistance from that plate. In other words, the mica sheet would serve to prevent the groundingl of the resistance-wire. In other respects the modification illustrated in Fig'. 9 is exactly like that shown in Fig. 8.

In Fig. l0 I have shown another form of' apparatus made in substantially the same way. In this case the lower metal plate l is made very thick and is provided with a deep recess into which the upper plate 5 is adapted to lit. This form of apparatus is very useful in an electric sad-iron, the flange of the plate l operating to prevent the influx of water into the resistance and insulation when, as often happens in the use of such sad-irons, they are dipped in water by operators to reduce their temperature.

The inleading wires for making internal connections to the resistance may consist of any suitable metal of larger cross-section or better electrical conductivity than the resistance-conductor and may be brazed or firmly clamped in any suitable way to the same. These terminals, which are marked l0 in the drawings, may be of any convenient number, depending upon the character and the purpose of the apparatus. In Fig. l a pair of' terminals lO l() are shown coming out from the opposite corners of the plate; but terminals may also be placed at intervening points, such as l1 l1.

In Fig. 5 the intervening glass plate 8 is represented as being made in two parts, around which the resistance is separately wound, the two parts of the resistance being connected at l2. A terminal may be inserted at 12, if desired, as represented in this Fig. 5.

Heretofore in some types of heaters it has been deemed essential that the insulation should adhere to or become apart of the plate to beheatedas, for example, where porcelain enamel or glaze has been used. In my invention it is not essential that the glass adhere to the metal; but, on the contrary, it is better that it should not so adhere, and to accomplish this result I treat the surface of the iron or metal plates l and 5 before heating with a thin coat of graphite or powdered soapstone or powdered mica or similar material to prevent the adhesion of the glass to the metal during the process of manufacture, or, as already explained, I insert between the insulating' material and the plates a sheet of mica or similar material as illustrated in Fig. 9.

IOO

IIO

aereos Asa result of this the apparatus can be more readily repaired or altered if it becomes necessary to insert another resistance while using the same plates, for the parts can be readily unscrewed or disconnected, and as the glass or insulating material does not adhere to the metal plates they can be taken apart and a new resistance and insulation substituted in the manner already explained.

The outer shell or casing or plate may con sist of one or more pieces, which may vary in thickness and shape as best suited to the requirements. For example, in an atmosphere-heating apparatus the surface of the plates may be extended in corrugations for increasing the surface for dissipating heat, or in an electric sad-iron one of the plates may be comparatively thick, so as to form the ironing surface or bottom of the iron, while the other plate would form the top of the iron. By forming recesses in the plates, and thereby providing flanges along their edges, I prevent the' overflow of 'the molten glass while it is under pressure and at a high temperature during the process of manufacture. In this way I also prevent the running or spreading of the glass when it is hot, which might destroy the resistance or cause its displacement and which might also thin out the insulation, especially at the edges. In this way also the glass is prevented from falling out around the edges of the apparatus in case of a fracture of the glass at these points due to heavy overload in service or to rough usage or any other such cause.

It will be seen that in the apparatus so constructed the resistance-wire is not only completely sealed from the atmosphere, but a thin wall of highly-electrical insulating material results, while at the same time the glass being pressed against the surface of the plates while molten makes intimate mechanical contact therewith, allowing of a ready conduction of heat. Such an apparatus is very strong and very durable. It has been' known to run in actual use for days at a temperature of at least 1,300O Fahrenheit without alteration of resistance or showing any weakness.

It is evident that two or more resistances with or without intervening layers of metal may be embraced between the outside casing or plates, according to requirements. It is also evident that instead of. metal other material may be employed in certain cases to form the outside shell or plates. Also flat metal ribbon or even carbon may be employed as a resistance instead of wire.

l/Vhat I claim as new, and desire to secure by Letters Patent, isi l. In an electrical resistance or heating apparatus, the combination of plates to be heated, a vitreous insulating material between said plates pressed between said plates when hot so as to conform to the shape of the plates and to I be in intimate contact therewith, and an electrical resistance sealed by the surrounding insulating material, substantially as described.

2. In an electrical resistance or heating apparatus, the combination of plates to be heated, an electrical resistance between said plates, a thin layer of vitreous insulating material ineasing and protecting the resistance and insulating it from the plates, the layer of insulating material being pressed between said plates when hot so as to entirely fill the space between said plates and being cooled in said position,

whereby there is close mechanical contact between the resistance, and the insulating material and between the insulating material and the plates, substantially as described.

3. In an electrical resistance or heating apparatus the combination of plates adapted to y form a mold in which the insulating material is pressed into shape, and thereafter to be used as the heat-conducting plates of the completed apparatus, an electrical resist-ance between said plates, a thin layer of vitreous insulating material incasing and protecting the resistance andinsulating it fromthe plates, the layer of insulating material being compressed between sid plates, and having an intimate contact with the resistance and the plates formed by being heated and cooled under pressure Ain contact therewith, substantially as described.

Ll. In an electrical resistance or heating apparatus, the combination of plates adapted to form a mold in which the insulating material is pressed into shape, and thereafter to be used as the heating conducting-plates of the completed apparatus, an electrical resistance between said plates, a thin layer of vitreous insulating material incasing and protecting the resistance and insulating it from the plates,

the layer of insulating material being compressed between said plates, and having an intimate contact with the resistance and the plates formed by being heated and cooled under pressure in contact therewith, and fastening devices to hold the parts firmly together, substantially as described.

5. In an electrical resistance or heating apparatus, the combination of plates to be heated, a vitreous insulating material between said plates, sheets of mica or-similar material between the insulating material and the plates, the insulating material being pressed between said plates when hot so as to conform to the shape of the plates and so as to cause the parts to be in intimate contact, and an electrical resistance sealed by the surrounding in sulating material, substantially as described.

6. In an electrical resistance or heating apparatus, the combination of plates adapted to form a mold in which the insulating material is pressed into shape, and thereafter to be used as the heat-conducting plates of the completed apparatus, an electrical resistance between said plates, a thin layer of vitreous insiO IIO

IIS

sulating material incasing' and protecting the resistance and insulating it from the plates, a sheet of mica or similar material between the insulatingmaterial and each plate, the insulating' material being compressed between said plates and having` an intimate Contact with the resistance and with the plates or the mica sheets, said intimate Contact being` caused by the heating and Cooling of the insulating ma- IO terial under pressure while in Contact with said parts, and 'fastening devices to hold the parts firmly together, substantially as' described.

In testimony whereof l have signed my name to this speeilieation in the presence of two subscribing' witnesses.

CHARLES E. CARPENTER.

Witnesses:

EDWIN Suelen, F. F. CRAMPTON.

Images