US 2431867 A
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Description (OCR text may contain errors)
Patented Dec. 2, 1947.
CHOKE R BALLAST AND FRAME THEREFOR Joseph J. Galla, Fair-field, Conn., assignor to The Stratfield Company, Bridgeport, Conn., a corporation of Connecticut Application July 26, 1945, Serial No. 607,147
16 Claims. 1
This invention relates to new and useful improvements in chokes or ballasts and frame therefor.
An object of the invention is to provide a choke or ballast including a mechanical construction or frame for holding the coil together with the E- and I-laminations firmly in place whereby the space or air-gap between such laminations is maintained constant to the end that there is a constant output from the device.
Another object is to provide a choke or ballast, as stated, and wherein the mechanical construction or frame provides for the secure wedging of a center arm of the E-laminations in the surrounding coil and the tight clamping together of the free ends of the outside arms of the E-larninations whereby hum or vibration is prevented.
Other objects and advantages of the invention will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawing wherein a satisfactory embodiment of the invention is shown. However, it is to be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention and the scope of the appended claims.
In the drawing:
Fig. 1 is a plan view of the blank from which the frame of the invention is to be formed;
Fig. 2 is an edge view of the same;
Fig, 3 is a view looking into the open end of the formed or bent-up frame;
Fig. 4 is a side elevational view of such frame;
Fig. 5 is a top plan view of the completed ballast or choke;
Fig. 6 is a side elevational View of the same; and
Fig. 7 is a sectional view taken as along the line 1-'! of Fig. 6.
Referring in detail to the drawing, the blank, generally designated ID, of Figs. 1 and 2, comprises a pair of side portions II and 12, each including a rail or wall-like portion l3 and an arm or extension l4. Between the side portions I l and I2 is a bight portion including mounting ears l5, each perforated, as shown, for the passage of securing screws or the like and a spring tongue portion 16.
The side portions l l and I2 are connected with portion I6 along the fold lines indicated by the dotted lines ll in Fig. 1 so that the end portions of IS arefree and such end portions provide spring lugs as will hereinafter appear. Additionally, side portions H and I2 are connected 2 with the ears [5 along the fold lines l8, which lines are, of course, in alignment with the fold lines I! at the respective edges of portion l6.
Each of the extensions M has a bead l9 pressed outwardly therefrom adjacent its inner end in parallel relation with the portion l6 and outwardly of such bead has a pair of longitudinally extending beads 20 placed outwardly therefrom and arranged in parallel relation with one another. Adjacent its outer or free end each extension M has an opening or perforation 2! for the passage of a rivet or the like as will appear. Side portions l3 adjacent their ends include ear-like extensions 22.
When the blank is folded as along the fold. lines H and 18, a generally U-shaped structure is provided and prior to the actual folding the portion I5 is set up whereby its free end portions 23 comprise spring lugs. In the completed choke or ballast the E-laminations 24 have their connecting portions located between the free end portions of the extensions l4 and a rivet 25 passes through the openings 2| in such extensions and through such portions of the laminations forcing the latter tight tog-ether and securing the frame in place.
The I-laminations 26 are disposed between the side wall portions 13 of the frame and are separated from the free ends of the arms of laminations 24 by any suitable separator 21. The coil 28 is not only about the center arm of the E- laminations but is also about the extensions 14 of the mechanical frame. In making the assembly, the I-laminations 26 are forced against the spring lugs 23 flattening or substantially flattening the latter and so when the rivet 25 is in place the E-laminations are held and the spring lugs exert a continuous pressure on the I-laminations 26 forcing them against the spacer 21.
This result is further enhanced by the expansion loops or beads I9 which are somewhat flattened when holding the parts together to position the rivet 25. The beads or embossed webs 20 of the extension l4 result in the creation of a pressure between the inner walls of the coil 28 and the central leg of the E-laminations.
Additionally, the ears or extensions 22 of the frame press against the free end portions of the outer arms of the E-laminations so that such portions are, in effect, clamped between the ears or extensions 22 at one side of the laminations 24 and those at the other side thereof. Thus, the entire assembly is tightly held and the clamping action by the cars 22 prevents vibration or hum.
With the described construction, it will be aptensions arranged in parallel relation, an outwardly pressed transversely extended bead substantially at the juncture of each of said extensions with its side portion, and a spring lug integral with said bight portion.
16. In a ballast or choke, a first body of E- laminations, a second bod of I-laminations, a frame including spaced arms and a connecting bight portion, said bodies disposed between the arms of the frame with the second body against said bight portion, means passing through the free end portions of said arms and the back portion of the first body and rigidly connecting said arms and portion, insulation between the free ends of the arms of the first body and the second body, a coil about the arms of said frame and the central arm of the first body, and resilient means carried by said bight portion and constantly urging the second body against said insulation.
JOSEPH J. GALLA.
REFERENCES CITED The following references are of record in the file of this patent: