US2367396A - Combination coil and resistor shield - Google Patents

Description

Jan. 16, 1945.- A. HALLETT I COMBINATION COIL AND RESISTOR SHIELD 7 t 5 2 m v a P fi 2 wag W n /w 1% U! b A. 7/ 7 o W 7 4 T W a w w w W W O v a W a 2 ATTORNEYS.

Patented Jan. 16, 1945 COMBINATION con. AND RESISTOR SHIELD Alfred Hallett,-Los Angeles, Calif., assignor to Hallett Manufacturing Company, Inglewood,

Califl, a copartnership I Application 'June15, 1942, 12 Claims. (01. 123-1455 This invention relates to the shielding and protection of electrical systems for internal combustion engines. 1

Free electrical radiations from ignition systems of internal combustion engines used in proximity to radio receiving apparatus are picked up in such apparatus and interfere with reception; This is a serious factor in the operation of airplanes, motorboats, submarines, military land vehicles, and all other types of mobile transportation, as wellas in-stationary installations, em;-

ploying radio equipment.

Various forms of shielding have been employed for thepurpose' of groundingelectrical radiai tions, but until my present invention I am aware of -no combination coil and resistor'shield which will serve the dual purpose of protecting the terminals of the coil and resistor from adverse effect of the elements and at the same time electrically shield the combinedunitto prevent undesirable radiations. f v

When the elements, of an ignition-system, such, for example as the coil and resistor, are exposed to'weather or adverse operating conditions, moisture, water, oil, and gaS may be deposited on the coil or the resistor unless protected by moistureproof and water-proof enclosures. Inasmuch as cables must lead to various parts of the combination coilv and resistor unit, such protective! means should include the regions where the caa bles enter the protective housing.

It is therefore anobject of my invention to.

provide an electrical shielding fora combination coil and resistor unit which combinesthe func-u tion of physical protection to the elements of the unit, against weather and-other adverse operating conditions which normally contribute to failure of the unit, deterioration of insulation,

connections, etc. f

It is a further and more specific-object of my Serial No. 447,078

ple' the coil known Scintilla. v

This applicationis a continuation in part of my copending applicationserial No. 427,621, filed,

under the trade name of January 21, 1942, for'Shielding for electrical systems.

These and other objects of *my invention will be made more apparent from aconsideration of the full description and drawing.

In the drawing: Y 1 i Figure 1 is a vertical view partly in section of my shielding applied to an ignition coil and re sistor unit. 3

Figure 2 isa cross-sectional'view of the same taken on the line 2--2 of Figure 1.

My combination coil and resistor shield assembly comprises generally a coil lfl, resistor H, and a shield housing 12 of substantially high conductive properties,

The coil illustrated is provided with a metallic casing I 3 having heat radiating fins I4, mounting brackets l5 for attaching the coil to the frame or motor, not illustrated, and a brass ring Iii .encircling the upper part of the coil. The coil illustrated and described 'is standard and commoniy known as the -Scinti1lacoil.

For use in conjunction with this coil I provide the resistor H. which primarily includes a coil invention to provide'a metallic shielding for an I individual coil and resistor unit, wherein the coil i may embody a metallic casing partially enclosing the shell around the winding's,as for examof resistance wire |1 attached to low tension connections I8 and Ilia, the latter of which are mounted upon an insulating block [9. The resistance element I! is preferably embedded in a casing in tubular form of investment cement 20 or any other-kind of material which is a nonconductor when dry, is preferably hard and has heat radiating properties.

My metallic shield housing I2 is of novel construction and comprises three primary parts 2|, 22, and 123. The part 2| and the part 22 cooperate to enclose and clamp upon the upper part of the coil, and the part 2| in addition provides an auxiliary compartment for the resistor unit. The part 23 functions as a cover. In design,.the parts 2| and 22 are in effect one, but are split at 24 to enable their installation upon the coil, and are secured together on'the coil by means of cap screws 25. The parts 2| and 22 are preferably formed with an annular channel 26 serving to engage and clamp upon the brass ring l6 of the coil, and are provided with extensions 21 which engage the upper edge of the metallic casing I3. l

As before stated, the part 2| is formed wit a compartment or pocket 30'into which the re sistor ll may be inserted, the resister being se-- terial is usually considered an artificial stone, the

basis of which is usually magnesium oxychloride. The resistor is connected to the coil circuit in conventional manner. 1

Heat radiating fins 34 may be formed on the wall of the resistor compartment.

I provide low tension terminals 35 entering the housing at the side, and a high tension, terminal 36 entering the housing through the cover.

In the case of the terminals it is desired to efiect a water-proof, moisture-proof and airtight seal where the cables enter the housing and also to assure a complete electrical contact between the metal shielding of the cables and the housing. Any suitable terminals which fulfill such requirements may be employed. However, I prefer terminals of the general character illustrated in my aforesaid copending application Serial 427,621.

The low tension terminal 35 comprises generally a metal collar 3'! threaded into an opening 0 3,8 in the housing. This collar is formed with an internal annular ledge 39. Snugly fittingwithin the collar is an insulator 40 having a shoulder 4| seating on the ledge 39 and being formed also with a beveled seat 42 at the upper end., Resting U in this seat is a frusto conical insulating gland 43 preferably of soft rubber. A metal bushing 44 having a vertical cylindrical portion through which the cable 45 extends and a. flat disc at thelower end is seated on the upper face of the gland- 4-3.. It. is preferable that the cylindrical portion of the bushing be inserted between the metal cable shielding 46; and the insulation 45a of the cable. The lower end of the shielding should be spread out over the disc portion of the bushing, and a ferrule 4:1: having, a flange at its. lower end rests upon the outturned shielding. and serves to. center the cable. A threaded cap 48 screws. down on the collar 3-!- to secure the various parts; tightly in place.

The shielding on the cables illustrated here is in the form of a woven metal sheathing but a tubular enclosure or other equivalent shielding for. the cable may be, employed.

The high tension terminal 36 involves certain modifications of the low tension terminal. It comprises generally a collar 31a. similar to the collar 31 and threadedinto an opening 381:. This collar is formed with a downward extension 31?). An insulator 400:. seats onthe internal ledge of the collar. In the high tension terminal it is preferred to space the shank 50 of the insulator from the major portionof the collar..

The cable 4.5a passes through a gland 43a and the insulator, the cable insulation 46aending at a, shoulder 5i formed by the reduced end 52 of the insulator. A metal bushing 44a which may be crimped upon-the cable shielding 41a or be otherwise secured upon it has a flanged portion resting upon the upper face of the gland 43a and is forced down by a cap 48a threaded upon the upper extension of the collar 3.1a;

The lower end of the cable wire 53 passes through the bore of a terminal element 54 and is I preferably soldered thereto. This element 54 has an upper shank 56 which fits snugly in the reduced lower end 52 of the insulator and a flange 51 which bears against the lower extremity of the insulator. A spring 58 is attached to the terminal element 54 and makes pressural contact with a conventional post (not illustrated) of the secondary winding in the coil within a hollow pedestal 60.

Both low tension and high tension terminals are locked securely to the housing, insuring an efficient and satisfactory connection with the coil and providing a moisture-proof and water-proof entry of the cable into the housing as well as a complete grounding of the metal cable shielding I r tothe housing.

Thus I have achieved an ignition coil and resistor unit completely enclosed in a structural sense as a protection against water, oil, and dirt and completely shielded electrically by a housing which has high conductive properties and which is positively connected with the cable shielding serving to dissipate into the ground all electrical radiations occurring in the unit. I have achieved an improved radiation of heat from the resistor, protection of the resistor elements and the connections of the resistor with the coil, and attained' a simplicity in connecting up the resistor and coil, as well as providing terminals for the leads of these two electrical elements; and have formed the common housing for the two elements of three pieces as described enabling them to be quickly and readily assembled on a standard type of coil of the character shown.

Although I. have herein shown and described my invention in what I'have conceived to be the most practical and, preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as .to embrace any and, all equivalent structures.

. Having described my invention, what. I claim as new and] desire to secure by Letters Patent is:

1. In combinationwith a coil. provided with a metallic casing and a'shouldered ring. secured on the coil above said, casing: a shield of high conductive properties comprising a split housing formed with a shouldered recess. adapted to engage and be clamped. upon said ring with said housing seating upon the upper end of said casing, a compartment in said housing, for a resistor, andv cable terminals entering said housing and establishing an electrical connection between metal shielding on said cables and the said housing.

2. In combination: a shield housing. of high conductive properties comprising a resistor compartment, a resistance element in said compartment, insulating heat radiating material packed in said compartment around said resistance element, cable terminals leading into said housing and establishing an-electrical connection between metal shielding-on said cables and the said housing, and means. adapted to clamp said housing over the upper portion of a coil contiguous toa metallic casing enclosing the lower portion of said coil whereby the coil and resistance element are entirely enclosed in an-electrical shield.

3. In combination: a. shield housing: of high conductive properties, comprising aresistor compartment, aresistance element in said: compartment, insulating heat, radiating material packed in said compartment: around. said, resistance element, cable terminals leading into said housing -coil whereby the coil and resistance element are entirely enclosed in an electrical shield, and means to obtain access to the upper end of said coil and to said resistance element for establish ing interconnections of coil and resistance element.

for establishing interconnections of coil and resistance element.

4. A combination as described in claim 2 in Y which the housing embodies a shelf adjacent the resistor compartment, and an insulating block mounted upon the shelf adapted" to support the resistance element.

5. In combination: a shield housing of high conductive properties comprising a resistor com-' partment, a resistance element insaid compartment, insulating heat radiating material packed in said compartment around said resistance element, moisture-proof and water-proof cable terminals leading into said housing and establishing an electrical connection between metal shielding on said cables and the said housing, and

means adapted to clamp said housing over the upper portion of a coil contiguous to a metallic casing enclosing the lower portion of said coil whereby the coil and resistance elementare en- I tirely enclosed in an electrical shield.

6. In combination: a shield housing of high conductive properties comprising a resistor compartment, a resistance element embedded insaid compartment, and means adapted to clamp said housing over the upper portion of a coil contiguous to a metallic casing enclosing the lower portion of said coil whereby the coil and resistance element are entirely enclosed in an electrical shield, said coil and resistance element being spaced apart for maximum heat dissipation.

7. In combination: a shield housing of high partment, a resistance element cementitiously embedded in said compartment, meansadapted to being spaced apart for maximum heat dissipation, and means to obtain access to the upper end of said coil and to said resistance'element 7 conductive properties comprising a resistor com- 8. In combination: a shield housing of high conductive properties comprising a resistor compartment, a resistance element in said compartment, and means adapted to clamp said housing over the upper portion of a coil contiguous to a metallic casing enclosing the lower portion of said coil whereby the coil and resistance element are entirely enclosed in an electrical shield,

said housing embodying a shelf adjacent the resistor compartment, and an insulating block mounted upon the shelf adapted to support the resistance element.

9. A combination coil and resistor shield comprising a housing of high conductive properties, said housing comprising two primary complementary parts adapted for clamping on an induction coil and formed with an annular recess for engaging a ring on said coil, and one of said primary parts including a receptacle for a resistor. I

10. A combination coil and resistor shield comprising a housing of high conductive properties,

said housing comprising two primary complementary parts adapted for clamping together upon an induction coil, and one of said primary parts including a resistor compartment spaced radially and laterally from said coil, for maximum heat dissipation. v

11; A combination coil and resistor shield comprising a housing of high conductive properties, said housing comprising two primary complementary parts adapted for clamping upon the upper end of an induction coil, one of said primary parts including a resistor compartment spaced radially from said coil, and a cover removably secured upon said complementary parts above the terminal end of said coil and above said resistor compartment, and having high tension cable terminal means providing electrical connection with cable shielding.

12. A combination coil and resistor shield comprising a housing of high conductive properties, said housing comprising two primary complementary parts adapted for clamping on an induction coil and formed with an annular recess for'engaging a shouldered ring on said coil, and

one of said primary parts having a resistor receptacle spaced from said coil and a resistor.

sealed in said receptacle.

ALFRED HAILETT.

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