US1628398A

US1628398A - Magnetic coil

Info

Publication number: US1628398A
Application number: US566421A
Authority: US
Inventors: William L Casper; Frank E Field
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1922-06-06
Filing date: 1922-06-06
Publication date: 1927-05-10
Anticipated expiration: 1944-05-10

Description

May 10,1927. 1,628,398

w. L.. CASPER ET AL MAGNETIC COIL Filed June 6, 1922 @my ma@ by j# im ,Wy

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Patented May 10, 1927.

VUNITED STATES PATENT OFFICE.

WILLIAM L. CASPER, OF BROOKLYN, NEW YORK, AND FRANK E. FIELD, OF SOMER- VILLE, NEW JERSEY, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR- PORATED, OF NEW YORK, N. Y., A CORPORATION 0F NEW YORK.-

MAGNETIC COIL.

Application filed June 6, 1922. Serial No. 566,421.

This invention relates to magnetic coils and particularly to transformers for tele phone currents and the like.

An object of the invention is to provide for readily adjusting the magnetic reluctance of a magnetic coil.

Another object 0f the' invention is to provide 1n a magnetic coil having a` Winding traversed by direct current, a magnetic circuit Which is very sensitive to alternating current to be transmitted, but relatively insensitive to changes in' direct current.

The invention further resides in various details of the coil supporting bracket or casing and in the structure and arrangement of the electrical terminals.

In one embodiment of the invention, a laminated shell type core is employed comprising an E-shaped section anda straight or I-shaped section. The Winding or windings surround the middle leg of the core, and a mounting bracket is employed comprising a housing which embraces the remaining portion of the core. `The housing may be of a single piece of sheet metal or of a plurality of' portions. In either case it comprises means for exerting a desired amount of lateral pressure on the core so as to vary the magnetic gaps between the sections. It has been found that where dire-ct current flows through one of the windings, an air gap is desirable in order to prevent saturation of the core. Convenient means is provided by this invention for Varying the gap so as to obtain maximum efficiency in the transmission of alternating currents, such as Voice currents.

Referring to the drawings:

Fig. 1 is a side elevation of one embodiment of the invention;

Fig. 2 is a front elevation partly broken away;

Fig. 3 is a plan View, partly broken away, of the form shown in Fig. 1;

Figs. 4, 5, and 6 are views similar to Figs. 1, 2, and 3 of another form of the invention' Fig. 7 is a detailed view of a terminal ernployed in the form shown in Fig.. 4.

Fig. 1 shows a transformer having a laminated core 10 comprising an E-shaped sec-y tion 12 and an I-shaped section 14. The laminations are preferably secured together by rivets, as shown at 16. The transformer windings 17 surround the central limb 18 of the core section 12. A casing or mounting bracket 2O is formed of a single sheet of metal bent so as to embrace the top and faces of the core. Openings 22 are provided in the sides of the casing through which the windings 17 project. At one side of' each open1ng'22 the metal is bent out to form a flange 24 carrying the terminal pieces 26. As shown in Fig. 3, each terminal 26 iis mounted in an insulating bushing 28. While four terminals are shown, the flanges 24 are obviously adaptable for mounting any desired number of terminals. At the edges of casing small flanges or tabs 30 are bent inwardly and by suitable means, such as a press, are forced against the edges of the

core members

12 and 14 so as to establish the desired amount of pressure on the abutting surfaces of the core sections. The surfaces are preferably plane and in most cases are in direct contact with each other, although under some conditions it may be desirable to interpose a sheet of paper or other material to assist in regulating the magnetic gap. The lower edges of casing 2O are bent outwardly to form flanges 32 adapted for attachment to a support.

The core of the transformer shown in Figs. 4, 5, and 6 is similar to that shown in Fig. 1. The casing or mounting bracket differs, however, in that it comprises two channel-shaped members 34 embracing the sides of the core. The channel members 'have inwardly extending

end flanges

36 and 38, andvat each inner edge adjacent the winding 17, a pair of ears 40. Bolts 42 pass through ears 40 ad serve the function of drawing the channel members toward each other and exerting pressure on the abutting surfaces of the core sections. Bolts 42 also serve to secure in position terminal plates 44, preferably made of insulating material. Mounted on terminal strip 44 are terminal pieces 46, one of Which is shown in detail in Fig. 7. An eyelet 48, passing through opening 50, secures the terminal `pieces to the plate 44. Terminal piece 46 is also provided with a projection 52 extending into a recess 53 and with

angular extensions

54 and 55 to which electrical conductors may be soldered.

A name plate 56 of aluminum or the like may be secured in position between flanges 36 and the core. Outwardly extending flanges 58 are provided at the lower end of channel members 34 for attachment to a support. Any suitable lining may be provided between the core and its casing or bracket, if desired.

While only two forms of the invention have been shown and described, it is to be understood that the invention is entitled to a reasonable range of e uivalents wjthin the scope ot' the appended c aims.

'lllc invention claimed is 1. A magnetic coil having a core comprising a plurality of layers of magnet-ic material, each layer comprising a plurality of sections, a frame comprising channel-shaped members embracing said sections, a terminal plate associated with said members and means for drawing said members toward each other and .securing said terminal plate in position.

2. A magnetic coil having a core comprising a plurality of layers of magnetic material, cach layer comprising a plurality of sections, a frame comprising a pair ot channel-shaped members embracing said sections, perforated ears on said members, a terminal plate interposed between said members and bolts passing through the perforations for drawing said members together and securing said terminal plate in position.

3. A magnetic coil comprising a shelltype core, a winding on the middle branch of said core, a casing having the form of a frame closely embracing the remaining portion of said core, a plate carried by said casing adjacent said winding and lying in a plane transverse to that of said core, and terminals mounted on said plate.

4. A magnetic coil comprising a plurality of laminated core sections, a frame cbmprising a pair of channel-shaped members embracing said sections, perforated ears on said members, bolts passing through the perforations for drawing said members together, a plate of insulating material secured to one of said ears, and terminals mounted on said plate.

5. A magnetic coil comprising a rectangular core, channel members embracing two sides of said core, said members having portions turned inwardly at their ends for embracing the ends of said core and having perfo 'ated portions turned outwardly, and bolts passing through said perforated portions t'or drawing said members toward each other.

6. A magnetic coil comprising a shell-type core, a winding on the middle branch ofsaid core, a casing having the form of a frame closely embracing the remaining portion of said core an insulated terminal plate carried by said casing and lying in a plane transverse to that of said core, and terminals mounted on said plate and connected to saidv