US2445196A - Sealed vibrator - Google Patents

Description

y 1948- H. E; WEST 2,445,196 SEALED VIBRATOR Filed June 21. 1944 INVENTOR.

mama July 13, 1948 2,445,196

um'rap STATES PATENT OFFICE SEALED VIBRATOR Harold E. West, Indianapolis, Ind., assignor to P. R. Mallory Jr 00., Inc., Indianapolis, Ind., a corporation of Delaware Application June 21, 1944, Serial No. 541,417

Claims. (Cl. 17418) 1 2 The present invention relates to vibrators, and, that there are many vibrator applications which more particularly, to vibratory electromagnetic make hermetic sealing of the vibrator mechanism interrupters hermetically sealed from the exterhighly desirable, if not absolutely necessary. nal atmosphere. Prior efforts in this direction have generally in- As those skilled in the art know, conventional 5 eluded a packing ring or packing member invibrators are generally mounted in metal casings ser-ted between the base plug and the can of the or cans which while suillcient to substantially vibrator. Although numerous suggestion and prevent the entrance of moisture and of dust do proposals were made to hermetically seal a vibranot eflectively oppose leakage of the gaseous attor by means of such expedients, none, as far as mosphere from or into the can in case there exis known, of these suggestions and proposals was ists a pressure differential between the interior completely satisfactory and successful when carof the can d the external at sphere. 'Ihus. ried into practice on a practical and commercial in general, it may be assumed that the vibrator scale. within the can is operated under atmospheric It is an object of the present invention to propressure. This circumstance causes certain dlfllll vide a sealed vibrator structure which avoids the culties when operating the vibrator under very difllculties and inconveniences experienced in conlow atmospheric pressure such as are, for examnection with conventional structures of the deple, frequently encountered in aircraft applicascribed character. tlons. Experience has demonstrated that at It is another object of the present invention to higher altitudes the rarified ,atmosphere will no provide a vibratory interrupter of novel and imcause arcing of the high voltage rectifier contacts, proved characters in which the interior of the fl ri n the interrupter or primary cont ct vibrator unit is hermetically sealed from the exand frequently also breakdown of the insulating temal atmosphere and which is capable of retainmaterial in the stack assembly. Generally speaking such condition indefinitely under the most exing, unsealed vibrator units cannot be successfully 26 acting operating conditions.

p ratedabeyond altitudes over to 20,000 feet It is a further object of the invention to proand when these altitudes are exceeded, destru vide a hermetically sealed vibrator unit characo o t t c ll t place quite api y. terized by the provision of a metal to metal seal imi difli u i s are e pe i ced in vib ator in the critical regions and which does not rely applications where weight is at a premium. In 30 n the pressure of a metallic member upon an vibrator power supplies of this type the transelastic packing materialo r prises the major percentage of the It is also within the contemplation of the inventot l w i ht. The weight c n be r c d by u in tion .to provide an improved base plug for vibraa minimum of core material but this expedient tors and other electrical appliances including a raises the flux density and the magnetizing curleak-proof plug having a metal sealing ring rentsto such values as to be dangerous to the molded th re n, said ring being adapted tobe hervibrator contacts when operation of the power metlcally bonded to the terminal edges of the s p ly is initiated. These difllculties ay be commetal can by means of soldering, welding, or other pensated for if the vibrator mechanism is placed similar operations. in a gaseous medium of such density as to make The invention also contemplates a hermetically pp rt of an are or of arcing conditions difllsealed vibrator unit which is simple. in construc- This desirable CDIIditiOII y be Obtained tion, which retains its sealed condition indefiniteby hermetically sealing the vibrator base plug ly, and which may be readily manufactured on a after assembly of the vibrator mechanism in the practical and commercial scale at a low cost. can and by raising the internal pressure within Other and further objects and advantages oi the can by means of suitable equipment until opthe invention will become apparent from the foltimum operating conditions are obtained. Addilowing description, taken in conjunction with the tional advantages may be obtained by the proper accompanying drawing; in which choice of a filling gas. Thus, employing a filling P18. 1 illustrates a vertical sectional view of a or of greater thermal conductivity and at an inso vibrator unit embodying the principles the creased pressure provides better cooling and a1-, present invention, and

lows a larger power output from a given unit by Fig. 2 depicts an elevational view of the plug prevention or contact material transfer and by portion of the vibra or shown in Fig. 7.. said view contact erosion. having parts broken away tor clarity of illustra- Irom the foregoing considerations it is clear tion.

" While apreferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made in the method of procedure and the construction of parts without departing from the spirit of the invention. In the following description, and in the claims, parts will be identified by specific names, for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring now more particularly to the drawing, reference character 10 denotes a metal can of generally cylindrical shape, the major portion of the inner surface of which is lined with a layer of sponge rubber I l. Within the said can there is provided a vibratory interrupter essentially comprising a hook-shaped ferromagnetic frame member l2 carrying a driver coil i3 around the hook end thereof and a stack generally denoted by reference character H at the other end thereof. In the said stack there are clamped a pair of side springs l5 carrying the relatively fixed contacts and a hinge plate or reed It to which there are secured reed arms l1 carrying the vibratory contacts. At the free end of reed 16 there is mounted an armature or weight l8 cooperating with the pole piece of driver coil l3. In view of the conventional character of this vibrator structure, no detailed description of its organization and of its operation will be necessary.

The stack portion of the vibrator is held within a suitable aperture or depression of member [9, likewise constituted of sponge rubber, yieldingly holding the lower end of the vibrator against displacement, through which flexible conductors 20 extend providing electrical connection between the electrical terminals of the vibrator and contact pins, or prongs, 2!.

The base plug comprises a disc 22 constituted of insulating material having at least some rigidity and strength, such as, for example, Bakelite. Base pins 2| extend through suitable apertures in said disc and are fixed therein. After mounting said pins in the disc, a layer 23 of elastic insulating material, such as natural rubber, synthetic rubber, or a suitable synthetic plastic material is injection molded around the disc and pins. This layer of elastic insulating material completely surrounds the surface of the disc and prevents the passage of gases therethrough, particularly around the pins. A metal ring 24 is molded to the'circumferential marginal portions of the eiastie layer and may be plated with a suitable metal, such as cadmium, to facilitate soldering thereto.

During the assembly of the vibrator unit, the inner ends of the base pins are electrically connected to flexible conductors 20 by means of soldering and the base plug is inserted into the open end of can in the position defined by the constricted portion 25 of the can. Thereafter, the terminal edges of the can are bent down against metal ring 24 to form a bead 26, a portion of which is flattened into face to face position against the lower surface of metal ring 24. This may be accomplished by means of spinning or pressing. Finally, the corresponding portions of bead 25 and ring 24 are soldered together around the circumference thereof, as indicated at 21, providing a permanent, hermetic, metal to metal seal. The interior of the vibrator can may be filled with air or some other gas under atmospheric, or increased pressure after head 26 and ring 24 are sealed. The filling with gas is accomplished through one of the hollow base pins through which the bare end of one of flexible conductors 20 extends and is left unsoldered for the purpose of leaving a tubular channel through which the gas may be introduced. After filling, this channel is sealed with solder concurrently with soldering the end of the conductor to the base pin.

It will be noted that the vibrator unit and the base plug of the invention provide a number of important advantages. First of all, the metal to metal seal provided in the critical regions is greatly superior to prior sealing structures in which the pressure of a metal surface upon the surface of a packing material is relied upon. The metal to metal seal of the invention is superior in strength, is not influenced by the slow deterioration of the packing medium and operates satisfactorily under adverse conditions, such as extremely high or low atmospheric temperatures, high pressure differentials, etc. Thus. vibratory interrupter units of the described type have been successfully operated under conditions corresponding to altitudes of 50,000 feet, and more, for periods of time equivalent to the normal service cycle of the associated equipment without any injury or damage to the hermetically sealed vibrator. Also, the sealed vibrator structure of the invention is quite simple and may be easily manufactured on a quantity production scale.

While the present invention, as to its objects and advantages, has been described herein as carried out in a specific embodiment thereof, it is not desired to be limited thereby but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is:

1. A hermetically sealed electrical appliance comprising in combination a metal casing open at one end thereof, an electrical mechanism within said casing, a base plug constituted of substantially rigid insulating material inserted into the end of said casing and having contact prongs extending therefrom electrically connected to said mechanism, a layer of elastic insulating material completely covering said base plug, an annular metallic member on the outer surface of said base plug and forming at one of its faces a hermetic seal with said layer of elastic insulating material on the plug, and a metal to metal seal between the other face of said annular member and the terminal edges of said casing for hermetically sealing the casing.

2. A hermetically sealed electromagnetic vibratory interrupter unit comprising in combination a metal can open at one end thereof, an interrupter therein, a substantially rigid insulative base disc for said can having contact pins extending therethrough and electrically connected to said interrupter, a continuous layer of an elastic insulating material molded around said disc and the base portions of said pins to render the same impermeable to gases, and a metal ring having one of its faces fluid-tightly connected to the outer surface of said elastic layer near the circumferential edges thereof, the circumferential edges of said can being brought into face to face position with the exposed surface of said metal ring and being fluid-tightly secured thereto with a metal to metal seal thereby to hermetically seal the interior of said can.

3. A hermetically sealed vibratory interrupter unit comprising in combination a metal can open at one end thereof, an interrupter vibrationlessly supported within said can, a rigid insulative base disc for the open end of said can having contact pins extending therethrough, flexible electrical connections between said interrupter and the ends of said pins within said can, a continuous layer of rubber-like insulating material molded around the surfaces of said disc and the externally protruding base portions of said pins to render the same impermeable to gases under pressure, and a metal ring fluid-tightly molded to the outer surface of said layer in proximity to the marginal portions thereof,- the circumferential edges of said can being bent into face to face position with the exposed surface of said metal ring and being fluid-tightly secured thereto with a continuous metal to metal seal thereby to hermetically seal the interior of said can.

4. A hermetically sealed vibratory interrupter unit comprising in combination a substantially cylindrical metal can open at one end thereof and having an annular constriction near said end, an interrupter yieldingly and vibrationlessly supported within said can, a rigid insulative base disc inserted into the end of said can into a position defined by said constriction, contact pins extending through said disc, flexible electrical connections between said interrupter and the ends of said pins within said can, a continuous layer of rubber molded around said disc and the outer base portions of said pins to prevent the passage of gases through the disc, and a substantially flat-surfaced metal ring fluid-tightly embedded in the outer surface of said rubber layer a Number near the circumferential edges thereof, the terminal edges of said can being circumferentialiy crimped into contacting position with the exposed surface of said ring and being soldered thereto to constitute a continuous fluid-tight metallic seal for the interior of the can.

5. In a hermetically sealed vibratory interrupter having a metal can and rigid base disc with outwardly extending contact pins, the improvement which comprises a layer of elastic insulating material molded around said disc and said pins, a metal ring molded in the outer surface of said layer. a continuous soldered seal between the circumferential edges of said can and said ring, and a gaseous medium at a higher than atmospheric pressure confined within said can.

HAROLD E. WEST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Kindl Nov. 10, 1931 Lilienfeld Oct. 4, 1932 Dressel Dec. 20, 1938 Peck May 28, 1940 Wood Mar. 9, 1943

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