US2764654A - Relay - Google Patents

Description

RELAY Albert F. Horlacher, Palatine, 111., assignor to C. P. Clare -& Co., Chicago, 111., a corporation of Illinois Application July 26, 1952, Serial No. 301,097

8 Claims. (Cl. 200-168) The present invention relates'to electric relays, and more particularly to improved contact structures for relays which are especially suitable for use in applications where they are likely to be subjected to considerable shock and vibration, required to be. operated by small currents, over a wide temperature range, and which are required to be hermetically sealed.

Many efforts have heretofore been made to devise relays for use in installations in .which vibration is prevalent and which are sealed and operated over considerable temperature ranges. Aircraft installations may be considered typical. It is thus an object of the present invention to provide a new and improved relay which is operable under the conditions mentioned, and which is also economical to construct and assemble.

A further objeetof the present invention is to provide a new and improved relay which is sealed in a container to render it immune to moisture and injurious elements,

whereby its field of use is expanded, and itsoperating life is increased. A further object of the present invention is to provide a new and improved contact structure, particularly adapted for relays, comprising a base or supporting structure in- 'cluding contact pins or terminals mounted in spaced apart relationship within a tubular. member and sealed thereto in gas-tight relation by a synthetic rubber compound vulcanized in situ under pressure. 7 I

A further object of the present invention is to provide a new and improved relay base and contact. structure, including means for securing the contacts or terminals in fixed and spaced relation, means for hermetically sealing the contacts to the base structure, and also providing the base structure with means whereby it can be secured in gas-tight relation to suitable relay housing means.

A further and more specific object of the present invention is the provision of a new and improved relay base and contact structure, including a tubular metallic shell, a pair of circular plates of rigid insulating material held in opposed spaced relation by the shell, a series of contacts or terminals extending through and rigidly secured to the plates, and sealing means extruded into the space between the plates and secured to the shell, plates and contact terminals and of a character such that it is effectively bonded or attached to the parts of the assembly.

A further object of the present invention is to provide a new and improved method for producing contact-base structures which comprises the steps of assemblinga tubular shell and end plates to forma hollow housing, inserting contacts or terminals through the plates, extruding a vulcanizable material such as a substitute rubber compound, e. g., neoprene, and more especially a material known as Fairprene obtainable from Du Pont under the number M-55 65, into the space bounded by the shell and character 10. relay disclosed and claimed in my copending application,

Patented Sept. 25, 1956 cone fiber glass, and preferably also a central supporting and bearing defining element of metal such as brass. The end plates are provided with a series of apertures for the reception of contact or terminal pins. The latter are provided with knurled portions so located that when the pins are inserted through the end plates they are held fixedly by the latter. The end plates are secured to the cylindrical shell and to the central supporting element with the contact pins preferably protruding through opposite sides of the assembly. Thereafter, and further in accordance with the invention, vulcanizable material such as the Fairprene M-5565 is inserted into a chamber defined by the end plates, shell and bearing structure, and cured or vulcanized slowly (for about a half hour) while maintained under considerable pressure and at an elevated temperature of about 300 F. The result is a very rigid and eflicient hermetically sealed base-contact structure that can be utilized for various purposes and particularly in the manufacture of hermetically sealed relays comprising a housing which can be secured to the shell.

Other objects and advantages of the present invention will become apparent from the ensuing description of an illustrative embodiment thereof, in the course of which reference is had to the accompanying drawing in which:

Fig. 1 is an axial cross-section through a relay conice structed in accordance with the invention, the view being taken generally along the line 11 of Fig. 2-, and with the movable contact structure omitted;

Fig. 2 is a transverse sectional View taken along the line 22 of Fig. l and showing but one of the several movable contacts with which the relay is provided;

Fig. 3 is an enlarged fragmentary cross-sectional view taken along the line 33 of Fig. 2; and

Fig. 4 is a sectional view illustrating apparatus utilized during the manufacture of the combined base and contact structure.

Referring now to the drawing, the relay of the present 1nvent1on is illustrated in its entirety by the reference It may include many features of the similar Serial No. 230,169, filed June the assignee of this application.

The relay may comprise two units 12 and14. Unit 12 consists of a cup-shaped housing 16 and a central axially 6, 1951, and assigned to extending core 18, both made of magnetic material. Unit l4 consists of the remainder of the relay and includes, in br1ef, a coil 20, a coil bobbin 22, a magnetic stator 24 1n intimate contact with the interior of housing 16 and located adjacent the lower (as viewed'in Fig. 1) end of bobbin 22 to which it may be secured, a rotor 26 rotatable about the lower end of core 18, a generally cupshaped contact actuator 28 of insulating material to which the rotor is secured and provided with a shaft 30 rotatably mounted in a counterbore 32 at the end of core 18 and In a counterbore 34 formed in a stud 36 secured to base structure 40 which is constructed in accordance with the present invention.

The rotor 26 and actuator 28 constitute an assembly.

' The actuator 28 has an axially extending peripheral outer end plates, and then vulcanizing it slowly in situ under wall 42 provided witha series of spaced apart axially extending 'slots into which the outer ends of the movable contacts 50 (of which but one is shown in Fig. 2) extend so that when the rotor-actuator is turned in response to the supply of electrical energy to the winding 20, the various contacts are moved as away from engagement with a first stationary contact and into engagement with a second contact. The stationary normally engaged contacts, which are shown as contact pins, are indicated by the reference characters 52 while the stationary normally nonengaged contacts are indicated by the reference characters 54. The movable contacts, it may be noted, are fixedly secured at one end to other stationary contact pins such as 56. The pins may be made of suitable material such as brass or silver.

The base assembly includes also the diametrically opposed pins 60 which are longer than the others and through which an energizing circuit for the coil 20 is completed through the tubular connectors 62, as best illustrated in Fig. 1.

As heretofore indicated, the contact structure is constructed in accordance with the present invention. It includes the various contact pins 52, 54, 56, and 60, and these are fixedly secured in hermetically sealed fashion in the base. The base includes a tubular, preferably circular shell 70 made of some suitable material such as brass, from which the stud 36 is also made. The base further includes a pair of generally circular rigid end plates 72 and 74 which are preferably made of silicone fiber glass. The plates are secured to the shell by the bent or rolled over end fianges 76 provided at opposite ends of the shell and defining internal shoulders at opposite ends of the shell. The stud is secured in central apertures in the end plates by bending or peening over the flanged end portions 78 of the stud which define external shoulders. It is seen that with this type of construction the end plates are rigidly and effectively secured in fixed spaced apart relation relative to each other by the shoulders on the end shell and stud against which the central and outer portions of the end plates abut.

In order securely and rigidly to hold the contact pins in position, the end plates are provided with a number of small spaced apart openings having diameters substantially equal to or slightly less than the outside diameters of the pins. The pins are provided with knurled portions 80 and 82, as best illustrated in Fig. 3, so that when the pins are driven into place in the end plates they will be structurally held rigidly in place by the knurled portions.

The contact pins are eflfectively hermetically sealed as is the remainder of the base structure inside of the shell in a novel manner. In accordance with the present invention there is introduced into the space or chamber, indicated by reference character 84 and provided by the shell and end plates, a substitute rubber compound, such as neoprene, known as Fairprene and obtained from Du Pont under the number M556'5. The neoprene is inserted into the space by apparatus such as that illustrated in Fig. 4 and it is therein slowly cured or vulcanized at an elevated temperature of about 300 F. and while maintained under a substantial pressure. Additionally to hold the pins, the latter may be provided with a series of annular grooves 86 into which the extruded and vulcanized neoprene extends.

One form of apparatus that can be used in carrying out the process of forming the seal is illustrated in Fig. 4. The apparatus here shown is of the type using a transfer molding process. It includes a supporting base structure 100 having an upstanding central cylindrical portion 102 surrounded by a tubular member 104 extending a short distance above portion 102 and providing a space at the upper end of the structure for the reception of the unfilled base structure 40. Portion 102 is provided with suitable apertures for the reception of the pins, of which only pins 60 are shown. It will be noted that the lower plate 72 is seated upon the support 102 and that a depressible press element 106 is shown seated upon the upper side of the top plate 74 whereby the plates are both held against movement away from'each other. Press-element 106 is also provided with suitable apertures for the reception of the terminal pins. It is also provided with a discharge opening "108 from which projects a nozzle 110 through which the neoprene can be supplied under pressure to the chamber 84, the upper-plate 74 being provided with a small opening 112 into which the nozzle 110 pro- :jects. The press element has associated with it a punch 114 adapted to be moved downwardly thereby to force the neoprene confined within a supply cylinder 116 through the discharge opening 108 of nozzle 110 into 4 the interior of the 'base structure. The neoprene is forced into the interior at a substantial pressure, say about one and one-half or two tons total for the base structure shown which has a diameter of approximately one inch. The neoprene is slowly vulcanized or cured while the pressure is applied by the applicationof heat thereto through the molding apparatus which may be maintained at an elevated temperature. The result is a construction in which the neoprene is very effectively bonded to the brass structures, such as the stud, end shell and contact pins, and yet good adhesion is achieved between the neoprene and terminal 'pins which may be made of coined silver instead of brass.

It has been found that neoprene known as Fairprene M-5565 cured at a temperature of about 300 F. and for a period of about one-half hour gives excellent results. It has been found that the neoprene is well bonded to the brass and adheres well to other materials such as the fiber glass and silver, if silver is used for the contact pins.

Another material that may be used is Fairprene M-SS'SO. It should perhaps be mentioned that the last two numbers indicate the durometer hardness of the material. The material should not be too hard because usually when it is hard it is loaded with more filler and this reduces the electrical resistance. Hardnesses of about 50 to 70 should be satisfactory. Also, a softer material is better in the present case because more efifective scaling is obtained and the softer material can be used because of the effective holding of the contact pins by the end plates.

From the foregoing description it is apparent that the base in terminal assembly can be fabricated readily and economically. There is produced an efiective sealing be tween the terminals and the base structure, and the latter can also be effectively sealed to the housing. To do this the open end of the housing is provided with an inset portion 120 into which the base structure is placed. The open end then is rolled over the base structure as indicated by the reference character 122, after which the rolled over parts can be sealed as by solder 124 thereby to provide avery adequately hermetically sealed structure. The interior of the housing can be evacuated and filled with inert gas if desired.

The apparatus of the present invention provides a mechanically accurate and rigid seal structure which is not likely to be adversely affected by shocks and vibrations and which will operate efiiciently over wide temperature variations and under widely varying conditions of various sorts. It enables low resistance contact pins to be utilized witheffective sealing and there is no likelihood of mechanical tolerances being exceeded during construction. While disclosed in connection with a relay structure, the invention may be utilized elsewhere.

While the present invention has been described in con: nection with the details of an illustrative embodiment thereof, it should be understood that it is not intended to be limitative of the invention except as set forth in the accompanying claims.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A contact structure, including in combination, a pair of rigid plates of insulating material, structure rigidly supporting said plates in substantially parallel spaced apart relationship to form a chamber and to prevent movement of said plates toward each other, contact pins secured to said plates, and a filling of synthetic rubber compound such as Fairprene M-5565 under pressure in said chamber vulcanized in situ to be bonded to said inner surface of said structure.

2. A contact structure, including in combination, a rigid tubular element configured to delimit a cavity, a plurality of elongated-contact elements supported in spaced relationship within said tubular element, and means including a filling of synthetic rubber compound such as Fairprene M-5565 vulcanized underpressure in situ in saidcavityfor a period of about a half hour at a temperature of about 300 F.

3. A contact structure, including in combination, a pair of circular, centrally apertured rigid plates of insulating material, means including a metallic cylindrical band secured to the outer peripheries of said plates and a stud secured to the central portions of said plates for supporting said plates in substantially parallel spaced apart relationship, contact pins mounted upon said plates and each having spaced apart portions configured non-rotatably securing the pin to each of said plates, and a filling of synthetic rubber compound such as Fairprene M5565 vulcanized in the region between the band and plates while maintained under pressure, at a temperature of about 300 F. and for a period of about one-half hour.

4. The method of constructing a contact structure com prising assembling a pair of plates, a plurality of contact pins and a tubular shell to form a base structure including the plates in parallel spaced apart relationship with the pins passing therethrough and the shell surrounding the periphery of the plates to form a chamber, introducing a vulcanizable rubber compound such as Fairprene M-5565 or M-5550 into said chamber, vulcanizing said compound in said chamber under pressure and at a temperature of about 300 F. for a period of about a half hour.

5. The method of constructing a contact structure comprising assembling a pair of plates, a plurality of contact pins and a shell to form a structure with the plates in spaced apart relationship within the shell and supporting the pins therein, introducing a vulcanizable synthetic rubber compound having a durometer hardness of about between 50 and 70 into said shell, and vulcaniz-ing said compound, while maintaining it under pressure against the pins, plates and interior of the shell, for a period of about a half hour and under a temperature of about 300 F.

6. The method of constructing a contact structure comprising assembling a plurality of elongated contact elements and a tubular shell means configured to delimit a cavity and to support said elements in spaced apart relationship with the elements at least in part within the shell, introducing a vulcanizable synthetic rubber compound such as Fairprene having a durometer hardness of about between 50 and 70 into said cavity, and vulcanizing said compound, while maintaining it under pressure against the elements and interior of the shell, for a period of about a half hour and under a temperature of about 300 F.

7. A relay, including in combination, a base-contact structure including a metallic tubular shell, said shell having internal shoulders at its opposite ends, a pair of silicone fiber glass end plates mounted in said shoulders and secured thereto by bent over end portions of said shell, each of said plates having a central aperture, a stud having external shoulders at its opposite ends, the ends of said stud passing through the central apertures in said plates and having its ends bent over the plates to secure the stud to the plates, said plates having a series of aligned apertures therein, contact pins passing through the apertures, a filling of synthetic rubber compound such as Fairprene M-5565 or M-SSSO, vulcanized under pressure, at a temperature of about 300 F. and for about a half hour, filling the region between the plates, shell and stud; and a housing element having an end portion encircling and hermetically sealed to said shell.

8. A relay, including in combination, a base-contact structure including a metallic tubular shell, said shell having internal shoulders at its opposite ends, a pair of silicone fiber glass end plates mounted in said shoulders and secured thereto by bent over end portions of said shell, each of said plates having a central aperture, a stud having external shoulders at its opposite ends, the ends of said stud passing through the central apertures in said plates and having its ends bent over the plates to secure the stud to the plates, said plates having a series of aligned apertures therein, contact pins passing through the apertures, said pins being substantially of the same size as the apertures and having knurled portions securely engaging the plates and grooved portions between the plates, a filling of synthetic rubber compound such as 'Fairprene filling the region between the plates, shell and stud and vulcanized therein under pressure for a period of about a half hour at a temperature of about 300 F.; and a housing element having an end portion encircling and hermetically sealed to said shell.

References Cited in the file of this patent UNITED STATES PATENTS 2,389,592 Bucklen et al. Nov. 27, 1945 2,451,810 Cohen Oct. 19, 1948 2,667,553 Moorehead et a1. Jan. 26, 1954 2,668,207 Bengtsson Feb. 2, 1954

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