US1878800A - Electromagnetic device - Google Patents

Description

p 1932- H. F. OBERGFELL ELECTROMAGNETIC DEVICE Filed Dec. 14. 1931 all 15m Herb EFT F. U]: E1-

Patented Sept. 20, 1932 UNITED STATES PATENT OFFICE HERBERT F. OBERGFELL, OF RIVER FOREST, ILLINOIS; ASSIGNOR, BY MESNE ASSIGN- MENTS, T0 ASSOCIATED ELECTRIC LABORATORIES, INC., OF CHICAGO, ILLINOIS, A :1

CORPORATION OF DELAWARE nmcmoimennrre nnv'rcn Application filed December 14, 1931. I Serial No. 580,895.

This invention relates to electromagnetic devices in general, but more particularly to electromagnetic devices such as induction coils and the principal object of the inven- 5 tion resides in the provision of a new and improved type of induction coil in which the spool heads of the coil are formed of moulded material which serves to support the coil as a unit and at the same time constitute terminal blocks for extending connections to the windings of the coil or for connections to other apparatus.

A further object of the invention resides in means in the combined spool heads and ter- 5 minal blocks for protecting and segregating the various conducting wires extending from the windings of the coil to the terminal connections on the spool head.

Further objects of the invention are concerned with the design of a new and improved induction coil which is economical to manufacture, is compact and sturdy in structure and presents a number of desirable advantages over previous types of induction coils.

It has been the practice, in the past, to

construct induction coils or electromagnetic devices with the windings of the coils wound directly around a laminated core and with a circular or disc shaped insulated spool head forced over each end of the core to hold the windings in place. With this type of structure it will be easily seen that'with rough handling, temperature changes or other causes, the structure of the coil is easily dam- 35 aged, the windings broken and the spool heads broken ofi resulting in an inoperative or defective coil which must be replaced or repaired. Similarly no provisions were made for protecting or supporting the short connecting leads extending to the windings. It was common practice to connect these directly to a separate terminal block mounted adjacent the induction coil and this structure therefore necessitated the utilization of considerable valuable space when the device is 'tion of the core 4. These ends 5 and 8 are incorporated, for example, in a telephone substation apparatus. By providing a device according to the invention the above difficulties and objectionable features are obviated.

The invention is disclosed in the accompanying drawing in which Fig. 1 shows a top view of the preferred embodiment of the invention. Fig. 2 is a side elevation partly in section; while Fig. 3 shows a perspective view of the device with the windings removed.

The induction coil, according to the invention, comprises primarily a laminated core 4, the opposite ends 5 and 8 of which are bent downward at right angles to the main pormoulded directly into the combination spool heads and terminal blocks 68 and 7. These blocks 6 and 7 may be formed of insulation material such as a phenolic condensation product known to the trade as bakelite. Bybeing poured into a mould in which the laminated core 4 is placed a rigid. sturdy, and compact structure results which can be of any desired shape and configuration, and due to the extension pieces 5 and 8 the blocks 6 and 7 will be prevented from being twisted and turned and separated from the core. The various coil windings 9 are wound directly upon and suitably insulated from the core 4 between the blocks 6 and 7 and as is well known, these induction coils may have several separate anddistinct windings so that a plurality of terminals must be provided for the connecting leads. By providing a structure in which the spool heads 6 and 7 are moulded directly upon the core 4 a structure is provided which will not be affected by moisture or other climatic conditions. Fiirthermore, the need for providing separate fastening means for holding together the plurality of separate laminations of the core 4 is obviated. I

In order to provide a means for mounting and supporting the coil as a unit the screw 90 holes 10 in block 6 and 11 in block 7 are provided.

The terminal portion of the blocks 6 and 7 provides a means for accommodating the terminal screws, such as 12, 13, 14 and 15 for example in block 6; similar screws being provided in the block 7. The terminals 12, 13 and 15 are provided with soldering tags 17 to which the various connecting leads extending from the windings of the induction coil are connected. The soldering tags 17, as clearly shown in Fig. 2, are riveted to brass studs 18 which are moulded directly into the insulated block. These brass studs 18 are tapped to receive the terminal screws.

Any number of soldering lugs and associated terminal screws may be provided. If it is desired however not to provide a soldering tag 17 the stud 16 is only provided and the screw such as 1 1 in block 6 is threaded into stud 16 and serves as a distributing point for apparatus other than the windings of the coil.

Projecting upwardly from theblock 6-, for example, and extending in close proximity to the terminal posts 12 and 13 are a series of protuberances or extensions 20 which are moulded integral with the block. Similar project-ions 21 surround the screw terminals 1 1 and 15 as is clearly shown in Fig. 3. The purpose of these projections around each terminal is to provide a means for securely holding and locking the spade terminal clips to which the connecting wires are attached, to the block. In placing the spade clips in position, the screw terminal 12 for example is loosened a sufiicient distance out of the stud 18, so that the spade clip can he slipped under the head after which the screw can be turned down on top of the clip. In case it should occur that the screws become slightly loosened upwhile the device is in use, it will be clearly seen that the projections 20 and 21 will prevent the-spade clips from completely pulling away from their associated terminal posts, thereby lessening the chances of causing any disconnection of the circuits to which the induction coil is connected.

In case it is desired, any number of additional spade clips and their associated connecting leads may be attached to the same terminal posts. By placing suitable extension studs on the mounting bolts provided in the holes 10 and 11, additional terminal posts may be provided so that other spade clips may be attached thereto and locked in position on the projections 26 and 27 formed in the blocks 6 and 7 respectively. The ter minal posts 12, 13, 14 and 15 may likewise serve as supporting or holding means for additional apparatus such as, for example, condensers, buzzers, etc. in additioncto serving as terminal posts for the connecting leads.

The connecting leads 30 from the windings of the coil 9 which are soldered to the sol dering tags 17 are arranged to lie in the slots 25 separated by projections 24 so there will be no danger of causing a short circuit or crossover between them. The slots 25, as is clearly seen in the block 7 of Fig. 3, are situated so that the connecting leads 30 are enabled to extend directly outwards from the winding of their respective coils. The reason for this is that as additional layers of windings are placed on top of one another there will be no danger of shearing, crushing or breaking the connecting leads and no special provisions for protecting these connecting leads are necessary as was in the prior types of induction coils. The slots 25 are. cut into the spool head slightly and extend upward to a point on about the level of the ends of the soldering tags 17. F urthermore, due to the fact that the blocks 6 and 7 are inherently constructed of insulating material no special provisions are required for insulating the connecting leads and bare wire conductors may be used, in which case it may be desirable to fill up the hollow space in which the conductors lie in each block with some suitable insulating compound.

lVhat is claimed is:

1. In an electromagnetic device, a laminated core, a combination spool head and terminal block moulded on each end of said core, each end of the core having a portion extending at an angle therefrom in the block for securely holding said blocks inspaced relationship on said core.

2. In an electromagnetic device, a laminated core having a downwardly projecting portion extending from each end thereof, a spool head moulded on each end of said core around said projections and held in position thereby, terminal means moulded in the top of said spool head for attachment of connecting wires, and means in the spool heads for supporting said device as a unit.

3. In an electromagnetic device, a laminated core having a projection formed on each end thereof, a combination spool head and terminal block formed around each of said projections, said blocks securely binding together the laminations of said core, and a plurality of terminal studs moulded directly into the top of said blocks.

4. An electromagnet comprising a core made up of a plurality of laminations, the ends of the core being bent at an angle, spool heads supported on each end of the core, said spool heads binding together said lamina tions, the angular ends of the core preventing displacement and turning movement of the spool heads, and a plurality of terminals mounted directly on top of said spool heads on the opposite side from the angular end of the core.

5. An electromagnet comprising a core and windings, each end of the core being bent downward at an an le, spool heads moulded on each end of the ent portion of the core, said bent portions preventing displacement of the spool heads, terminal posts mounted on the top of said spool heads on the opposite end from the downward portions of the core, and a plurality of slots formed in the side of each spool head to protect and insulate the conducting wires extending from the windings of the coil to the terminal posts.

In witness whereof, I hereunto subscribe my name this 11th day of December, A. D.

HERBERT F. OBERGFELL.

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