US1234280A

US1234280A - Electric heating device.

Info

Publication number: US1234280A
Application number: US13369816A
Authority: US
Inventors: Francis Charles Edward Burnett; Ernest John Brunning
Original assignee: Individual
Current assignee: Individual
Priority date: 1916-11-27
Filing date: 1916-11-27
Publication date: 1917-07-24
Anticipated expiration: 1934-07-24

Description

F. C. E. BURNETT & E. J. BRUNNING'.

ELECTRIC HEATING DEVICE.

APPLICATION FILED NOV. 27, I916.

1,234,280. Patented July 24, 1917.

2 SHEET SSHEET 1.

Alma; 117mm REL-EUR E77- W E. IJHBRUIINIHE.

F. C. E. BURNETT & E. J. BRUNNING.

ELECTRIC HEATING DEVICE.

APPLICATION FILED NOV. 2?. 1916.

Patented July 24, 1917.

2 SHEETS-SHEET 2 Jiumms 55'. 5.312775 77,- E JHFIY HIV/NE:

U/T/VEFE UNITED STATES PATENT OFFICE.

I'BAIGIS BURNETT AND ERNEST JOHN IBBUNNIRG, 0F MONTREAL, QUEBEC, CANADA.

Speculation of Letters Itatcnt.

ELECTRIC nnarnsre DEVICE.

Patented July 24, 1917.

Application filed Iovenibcr 87, 1916. Serial No. 133,898.

To allwbomitmayconcem;

Be it known that we, FRANCIS C Enwm 13mm and ElmmrJolm BRUN- Nmc, both subjects of the King of Great Britain, and residents of the city of Mongaging the of the gun. It is obvious,

however, that the method here described is applicable to the heating of-any complete circuit of metal for the tempering or annealing or other p It has already been proposed to heat metallic rings in a device in which the rings constitute the secondary circuits of a transformer. The objects of the present invention are to provide improvements in this apparatus, to secure more satisfactory and accurate operation thereof under commercial conditions, and to make such improvements in the electrical connection which will enable the various circuits to be regulated to suit conditions. The invention comprises the improved construction and arrangement of parts hereinafter described in detail in the accompanying specification and drawlugs- In the drawings: Figure 1 is a sectional elevation through an embodiment of the invention.

Fig. 2 is a cross section on the line 2-2, 1

Fig 3 is aside elevation with the refractory chamber for the ring to be heated removed, and having the wiring indicated diae r- Fig. 4 shows diagrammatically the electrical connection by which thefvoltage is Fig. 5 shows diagrammatically the method employed to control the primary electric circuit.

In the drawings like characters of reference refer to corresponding parts in each ferring to the A represents a magnetic core or circuit conveniently built up of suitable plates of iron or steel, and in the embodiment illustrated, being of rectangular form. A portion B, in this case the top portion of the core, adapted to be raised and lowered by suitable means such as the lever C which is shown pivoted to a support D.

E represents a primary winding mounted on one side of the magnetic core and consisting of a suitable number of turns in a conductor wound in the usual way, current beiigl1 supplied from the conductors 10 an It is important to insure that the circuitthrough the primary winding should not be completed until the movable part of the is movable and is core 1s in exact position, as otherwise the back E. M. F. in the primary winding would not be great enough and the current would be too high.

To perform this function, I provide a contact 12-on the lever C adapted to cooperate with a suitable fixed and adjustable contact 13 on the support 14, the conductor 10 being connected to the contact 12 and a conductor 15 leading from the contact 12, the conductor 11 and conductor 15 being connected to the double pole switch 16 which 1s suitably connected to a source of electric power.

The movable to the other part of the magnetic core, but

small air gaps

20 and 21 may be left between and a further regulation in the amount of heating may be made by adjusting the amount of this air gap through the adjustment of the fixed contact 13 in any convenient way.

It will be observed that the reluctance of the magnetic circuit may be alternated at will to suit the needs of the case by varying the

air gaps

20 and 21, or inserting pieces of non-magnetic material in these air gaps.

Surrounding the prima winding E, is a casing C of suitable re actory material adapted to contain the ring to be heated. This case is annular in form and serves the double purpose of minimizing the loss of heat fromthe material to be heated and protecting the primary winding and the magnetic core from injury, due to the heat radiated or conducted from the material to be heated.

, H represents the ring to be heated and part B need not exactly fit which is located in the chamber G and will constitute the secondar circult. The top or cover 24 of the re actory chamber 1s connected by suitable brackets 25 to the movable part B andis adapted to move therewith.

In operation the lever C is raised, carrym the part B and cover 24. The metal rlng to be heated is then placed in the chamber G and the switch 16 thrown into operative position and the lever 0 brought down. As soon as the contacts 12 and 13 meet the circuit will be completed through the primary winding E which will induce a heavy current in the article H which forms 'the secondary in which heat may be maintained as long as the current is on. When the heating is completed, the switch 16 may be opened and the lifting of the part B Wlll carry the cover 24, permitting the removal of the heated article.

Under certain conditions it may be desirable to vary the voltage in the arrangement above described and the preferred manner of doing this is shown in Fig. 4;, in which E represents the primary winding in Fig. 1. 10 and 11" indicate connections from the winding E to a double pole switch 16. K represents auto-transformer having a winding 30 on a magnetic core 31, the construction and operation of which is well known in,the art and this transformer is in the circuit between the primary winding E and the switch 16.

If it is desirable to regulate the primary circuit by non-inductive means, it may be done as shown in Fig. 5, in which E mdicates the primary winding, 10 and 11 connections between it and a double pole switch 16, any one of which connections, such as 11 a non-inductive resistance 22 is inserted in series with the wire 11.

As many changes could be made in the above construction and many apparently widely different embodiments of our invention, within the scope of the claims, constructed without departing from the spirit or scope thereof, it is intended that all matter contained in the accompanying specifications and drawings may be interpreted as illustrative and not in a limiting sense.

What we claim as our invention is:

1. An electric heating device comprising in combination a rectangular magnetic core having a movable top portion, means for raising and lowering the top portion, a primary winding mounted on one side of the magnetic core, an annular casing surrounding the primary winding adapted to contain a ing on the core, an annular chamber adapted to contain the article to be heated and surrounding the primary winding.

3. An electric heating device comprising a magnetic core having a movable part, a primary winding, a secondary winding formed by an article to be heated, and means preventing the completion of the current through the primary winding until the movable part of the magnetic core is in proper relative position to the other part.

4:- An electric heating device comprising a magnetic core having a movable part, a primary winding, a secondary winding formed by an article to be heated, and means preventing the completion of the current through the primary winding until the movable part of the magnetic core is in proper relative position to the other part, said means comprising a fixed contact and a movable contact moving with the movable part.

In witness whereof we have hereunto set our hands in the presence of two witnesses.