US2417990A - Solenoid - Google Patents

Description

R, M. NARDONE SOLENOID` Filed sept '7' 1944 March 25, 1947.

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A TTRNEY Patented Mar. 25, i947 2,411,990 soLENom Romeo M. Nardone, Teaneck, N. J., assignor to Bendix Aviation Corporation, Teterboro, N. J., a corporation o! Delaware Application September 7, 1944, Serial No. 553,069

My invention relates to electromagnetic apparatus, and more particularly to the mechanical construction thereof.

Electromagnets of the solenoid type are used extensively in installations of a character involving associated parts wherein vibrational and other disturbances are set up, which disturbances, when communicated to the solenoid assembly, tend to cause corresponding, but quite objectionable vibration and sometimes equally objectionable reciprocatory movements of the solenoid plunger with the result that the sleeve, in which the plunger is mounted, becomes unduly worn within a relatively short period therebynecessitating replacement. f

One of theobjects of my invention is to provide a solenoid equipped with means for counteracting the aforementioned tendency and for controlling the effect thereof upon the solenoid plunger whereby wear on the plunger sleeve is maintained at a minimum.

Another object of my invention is tol provide a solenoid wherein the inter-relationship, method of assembly, and the operationI of the various components not only contribute to th construction of an extremely compact device but serve to preclude noise or chatter occasioned by vibration.

A further object of my invention is to provide a solenoid of the foregoing described character which is equipped with a coil assembly capable of being inserted within the solenoid casing as a unit thereby permitting the coil assembly to be tested before being encased and to be easily replaced if desired.

An important object of my invention is to provide a solenoid of the foregoing described character which is simple in construction, durable in use, efficient in operation, economical in manufacture and relatively silent when deenergized.

With the above and other objects in view, as

will hereinafter appear, the invention consists in the combination, and arrangement of parts hereinafter set forth and illustrated in the accompanying drawings, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

Referring to the drawing wherein like reference characters designate like parts throughout the several views,

Figure l is a side elevation of my solenoid construction illustrated in conjunction with a portion oi an engine starting device.

Figure 2 is a perspective view of my invention illustrated in association with the brush actu 2 claims. (ci. 11s-341) 2 ating ring of the motor of the aforementioned device.

Figure 3 is-a perspective" view of my invention looking towards the plunger projecting end thereof.

Figure 4 is a sectional view taken on the line 1 4 `of the Figure 2.

Figure 5 is a disassembled perspective view of the coil assembly and casing units, the latter unit being broken away to illustrate the fixed pole-piece therein.

Figure 6 is a disassembled perspective view of the plunger and interlocking pin.

Figure 7 is-a sectional view taken on the line 'I--1 of Figure 4.

In practicing my invention, as illustrated in the drawings, I provide a casing unit I0 comprising cylindrical metallic shell or casing I I hav-v ing an. open end and provided with radially disposed ilanges I2 adjacent said open end. The opposite end of the casingvis integrally formed with an end wall I3 provided with a central aperture in which is disposed a shank Il formed on the radial end face oi' a xed pole-piece or magnetic plug I5 disposed axially within the casing. 'Ihe shank I4 is formed on its outer end with a circumferential lip IB coacting with the radial end face to secure the plug to the end wall I3 and in iixed relation therewith. The circumferential face of the casing, adjacent the margin of the end wall I3, .is provided with a hole I'I, the purpose of which will hereinafter be mor fully described.

A coil assembly unit 20 is arranged within the casing and is introducible therein as a unit, and which comprises a closure plate 2l transversing the open end of the casing and provided with flanges 22 engaging ilanges I2 and formed with a centrally disposed opening 23 and an outwardly 4disposed rib 24 surrounding the opening, the

latter having ilxed therein one end of a nonmagnetic guide sleeve 25 on which is mounted an exciting coil 26. The opposite end of the sleeve 25 is provided with a collar 21 coacting with the plate 2l to maintain the'coil 28 therebetween, said collar being connected to one lead wire 28 of the coil 26 and engaging the casing I0 to establish a ground connection between the coil and casing. The other lead wire 29 of the coil is insulated and extends through a notch 30 formed in the periphery of the collar and out of the casing through the hole I1 as depicted in 25 tightly embraces the nlug I5 and forms a seal f therewith to preclude the escape of air therebetween from within the sleeve for a purpose hereinafter made apparent. By thus disposing the plug within the sleeve, the plug serves to maintain centralization of the unit 20 within the casing. An interlocking element or pin 3l is disposed in parallel relation with the sleeve and extends axially through the rib 24 and plate 2| and the adjacent end face of the sleeve 25 for securing the sleeve to the plate against relative rotation, a side portion 32 of the pin projects and extends longitudinally within the bore of the sleeve 25.

A movable pole-piece or magnetic plunger 35 is slidably mounted within the sleeve and has its circumferential face formed with a longitudinal groove 36 receiving the portion 32 of the pin 3| whereby rotation of the plunger relative to the sleeve 25 is precluded. The confronting faces of the plunger 35 and plug l5 are formed with aligned sockets 31 receiving therein opposite ends oi a coil spring 38 which functions to urge the plunger away from the plug when the solenoid is deenergized thereby establishing an air chamber 39 between the plunger and plug as clearly illustrated in Figure 4 of the drawings. Obviously, when the solenoid is energized, the plunger is actuated in a direction towards the plug and the air contained between the 'plunger and plug is forced outwardly therefrom about and between the sleeve 25 and plunger 35, it being borne in mind that the plug l and sleeve 25 are tightly fitted to form a seal therebetween. The opposite end face of the plunger is formed with a diametrically reduced projecting end section 40.

The plunger 35 is of a suitable diameter to establish a relatively close t with the sleeve 25 for decelerating the escape'of air, about and between the sleeve and plunger, from the chamber thereby counteracting vibratory reciprocation of the plunger when the solenoid is deenergized with It is obvious that the invention is not confined to the herein described use therefor as it may be `itilized for any purpose to which it is adaptable. It is therefore to be understobd that the invention is not limited to the specific construction as illustrated and described as the same is only illustrative of the principles of operation, which are capable of extended application in various forms, and that the invention comprehends all construction within the scope of the appended claims.

What is claimed is:

l. In a solenoid construction, a hollow casing open at one end and closed at the other by an end wall; `a plug of magnetic material axially disposed within said casing and having one end secured to said end wall; a. unitary coil assembly disposed within said casing, including a closure plate at the open end of said casing, said plate having a central opening in axial alignment with said plus; a sleeve of non-magnetic material axially disposed within said coil assembly, said sleeve having one end projecting into the central opening and secured to said closure plate while its other end is removably mounted on the free end of said plug to effect relative centralization, said plug and sleeve being formed relatively to provide an air seal between the engaging portions; an energizing coil mounted on said sleeve; a collar fixed to the inner end of said sleeve and coacting with said closure plate to maintain said coil therebetween against axial displacement, said collar the result that wear on the sleeve by the plunger Y is minimized.

The flanges I2 and 22 are provided with registering openings 4l for the reception of screws i not shown) whereby the solenoid may be secured to another device with which it may be operatively associated, for example, a starter of the character disclosed in my co-pending application, Serial No. 525,417, led March 7, 1944, of which this application is a continuation-impart. When utilized in conjunction with said starter, the end section 40 of the plunger 35 extends through an opening formed in the wall or partition member 92 of the casing section and on which member 52 there is mounted a brush ring Ill provided with a radially outstanding lug IIB which is engaged by the end section 40 of the plunger 35, the operating relation of the ring I Il and solenoid being fully disclosed in the aforementioned co-pending application.

From the foregoing, it will be apparent that my invention provides an extremely simple and compact solenoid capable of being easily tested and assembled due to the unique and novel construction and arrangement of the units and their various components,

Without further elaboration the foregoing will so fully explain the invention that others may,

'by applying current knowledge, readily adapt the same for use under various conditions of service. Moreover, it is not indispensable that all the features of the invention be used conjointly since they may be employed advantageously in various combinations and sub-combinations.

\ engaging said casing to establish a ground connection between said coil and casing; a plunger of magnetic material slidably mounted in the other end of said sleeve/and movable towards said plug when said assembly is rendered effective; and a spring interposed between said plug and plunger for urging the latter away from said plug when said assembly is rendered ineffective and to thus provide an air chamber therebetween, said plungdisposed within said casing, including a closure.

plate at the open end of said casing, said plate having a central opening in axial alignment with said plug; a sleeve of non-magnetic material axially disposed within said coil assembly, said sleeve having one end projecting into the central opening and secured to said closure plate while its other end is removably mounted on the free end oi said plug to effect relative centralization, said plug and sleeve being formed relatively to provide an air seal between the engaging portions: an energizing coil mounted on said sleeve; a collar fixed to the inner end of said sleeve and coacting with said closure plate to maintain said coil therebetween against axial displacement, said collar engaging said casing to establish a ground connection between said coil and casing; a plunger of magnetic material slidably mounted in the other end of said sleeve and movable toward said plug when said assembly is rendered eiective; and a spring interposed between said said plug when said assembly is rendered ineiiec- 5 6 tive and to thus provide an air chamber therebetween; interengaging means on said closure REFERENCES CITED Plate and plunger t0 restrict the latter for move The following references are of record in the ment in an axial direction, said plunger and me of this patent; sleeve being formed relatively of such diameters 5 as to decelerate the flow of air therebetween for UNITED STATES PATENTS cushioning vbratory reciprocations of said Number Name Date plunger when said coil assembly is rendered nef- 2,343,806 Scofield Mar. 7, 1944 fective. 2,353,835 Lane July 18, 1944 ROM'EO M. NARDONE. 10 2,361,826 Dowden Oct. 31, 1944

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