US3840832A

US3840832A - Relay having a plurality of sealed contact switches

Info

Publication number: US3840832A
Application number: US00400904A
Authority: US
Inventors: G Bowers
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1973-09-26
Filing date: 1973-09-26
Publication date: 1974-10-08
Anticipated expiration: 1991-10-08

Abstract

An industrial relay including a plurality of hermetically sealed contact switches therein. The relay further includes a ferromagnetic structure having a bottom member, first and second side members extending upward from the bottom member, and first and second top members extending toward each other from the side members and defining respective first and second pole faces and a gap therebetween. Each of the top members has a top surface and first and second side surfaces. The first pole face is in a plane perpendicular to the side surfaces and at an acute angle with the top surface of the first top member, while the second pole face is in a plane perpendicular to the top and side surfaces of the second top member. An energizing coil is positioned around the bottom member of the ferromagnetic structure. A plurality of the sealed contact switches are directly affixed to the top and side surfaces of the top members and adjacent the pole faces. The above-described components are containable in a suitable enclosure.

Description

Bowers Oct. -8, 1974 [54] RELAY HAVING A PLURALITY OF SEALED CONTACT SWITCHES [75] Inventor: Gerald Joe Bowers, Bloomington,

[73] Assignee: General Electric Company, New

. York, NY.

[22] Filed: Sept. 26, 1973 [21] Appl. No.: 400,904

[52] US. Cl 335/152, 335/153, 335/281 [51] Int. Cl. H01h 51/22 [58] Field of Search 335/l51-154,

[5 6] References Cited UNITED STATES PATENTS 3,146,327 8/1964 Ohki et al. 200/241 3,264,425 8/1966 Hosokawa et al. 335/153 3,472,141 10/1969 Hilbig et al. 335/281 Schlamp; R. G. Simkins [5 7] ABSTRACT An industrial relay including a plurality of hermetically sealed contact switches therein. The relay further includes a ferromagnetic structure having a bottom member, first and second side members extending upward from the bottom member, and first and second 'top members extending toward each other from the side members and defining respective first and second pole faces and a gap therebetween. Each of the top members has a top surface and first and second side surfaces. The first pole face is in a plane perpendicular to the side surfaces and at an acute angle with the top surface of the first top member, while the second pole face is in a plane perpendicular to the top and side surfaces of the second top member. An energizing coil is positioned around the bottom member of the ferromagnetic structure. A -plurality of the sealed contact switches are directly affixed to the top and side surfaces of the top members and adjacent the pole faces. The above-described components are containable in a suitable enclosure.

9.1?!aims7 Dreiv nef urs RELAY HAVING A PLURALITY OF SEALED CONTACT SWITCHES BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to relays, and more particularly to relays having a plurality of sealed contact switches included therein.

2. Description of the Prior Art An industrial relay which has a plurality of sealed contact reed switches positioned in the proximity of the pole faces of a U-shaped magnetic structure has been previously manufactured. GEnerally the U-shaped magnetic structure, due to the relatively large distance between the pole faces, provides a relatively high reluctance path for the magnetic lines of flux passing therethrough when the coil of the relay is energized. The' magnetic circuit created by this particular type of structure thereby produces a relatively low inductive reactance in the electric circuit of the device and cannot be expected to provide adequate filtering for current pulses originating in an AC source which is connectable to the coil winding of the relay through a full wave rectifier bridge.

Furthermore when as many as four sealed contact switches are used in one relay, they are usually positioned over the pole faces of the above described ferromagnetic structure. This requires that the width of the structure be of sufficient dimension for reliably mounting all of the sealed contact switches thereon. Under these circumstances the overall cross-sectional dimension of the structure is relatively large thereby causing the coil to have a relatively long mean turn length. This results in an increase in the resistance of the coil per turn ratio since the average turn is relatively far from the structure.

Still further when it is desired that one of the sealed.

contact switches is to be adapted to operate in a normally closed mode, a permanent bar magnet is attached to the insulative housing of that switch. If that switch is not sufficiently magnetically isolated from any adjacent sealed contact switch, the bar magnet can interfere with the proper performance of any adjacent switch.

OBJECTS OF THE INVENTION It is therefore an object of this invention to provide an improved relay which includes a plurality of sealed contact switches, wherein a ferromagnetic structure associated with the switches is shaped to produce a relatively high inductive reactance circuit which is used to filter DC current pulses introduced from a rectified AC power source.

It is another object of this invention to provide an improved relay which includes a ferromagnetic structure that has a reduced cross-sectional area for a given number of sealed contact switches mounted thereon, thereby resulting in a shorter mean turn length for a coil positioned around the ferromagnetic structure.

It is a further object of this invention to provide sufficient magnetic isolation between the adjacent sealed contact switches positioned on the ferromagnetic structure so that any switch which has been adapted to operate in a normally closed mode will not interfere with the operation of any other switch adjacent thereto.

Other objects of the invention will ge pointed out in and understood from the following.

SUMMARY OF THE INVENTION In accordance with a broad aspect of the invention there is provided an improved relay comprising a plurality of sealed contact switches affixed to a ferromagnetic structure. The structure includes a bottom member, first and second side members extending upward from the bottom memher, and first and second top members extending toward each other from the side members and defining respective first and second pole faces and a gap therebetween. Each of the top members has a top surface and first and second side surfaces. The first pole face is in a plane perpendicular to the side surfaces and at an acute angle with the top surface of the first top member. The second pole face is in a plane perpendicular tothe top and side surfaces of the second top member. An energizing coil is positioned around the bottom member of the ferromagnetic structure. The sealed contact switches are directly affixed to the top. and either one or both of the side surfaces of the top members and adjacent their pole faces. It is preferable that the switches which are to be adapted to operate in a normally closed mode be placed along the side surfaces of the top members.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of those components which comprise the ferromagnetic structure and energizing coil for the relay;

FIG. 2 is an assembled perspective view of the components shown in FIG. 1;

FIG. 3 is a partial enlarged view of another embodiment of the gap and pole faces for the ferromagnetic structure shown in FIG. 2;

FIGS. 4, 5 and 6 are respective top, front and side views of the structure shown in FIG. 2 after a plurality of sealed contact switches have been affixed thereto;

FIG. 7 is a perspective view of a housing enclosure for the relay.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 4 through 6, a relay 10 is comprised of a ferromagnetic structure 12, coils l4 and 16 and a plurality of sealed

contact reed switches

18, 20, 22 and 24. I

Structure 12 is made of any suitable magnetic material such as laminated silicon steel, and, as shown in FIG. 1, is initially comprised of a first section 26 and a second section 28. Section 28 is U-shaped, while section 26 is C-shaped with its lower leg portion 30 extending out beyond the remainder of section 26. As shown in FIG. 1, coil 14 has a slot 32 for receiving lower portion 30 of section 26 and coil 14 is assembled on lower portion 30. Similarly coil 16 has a slot 34 therein for receiving a lower portion 36 of section 28, and coil 16 is positioned on lower portion 36 of section 28. After the above described positioning of coils l4 and 16 on the respective lower portions 30 and 36 of

respective sections

26 and 28, ferromagnetic structure 12 is formed by joining respective end faces 38 and 40 of respective lower portions 30 and 36 to form a unitary piece as shown in FIG. 2.

Sections

26 and 28 can be joined at theirrespective end faces 38 and 40 using suitable mechanical fastening means or bonding agents.

One such suitable bonding agent is a methyl acrylic compound sold under the brand name Eastman 910 adhesive and manufactured by the Chemicals Division of the Eastman Kodak Company. This bonding agent has the advantage that it cures almost immediately. Another suitable bonding agent for this purpose, and which also cures almost immediately, is a two part product made by CIBA Products Company, the first part being an Araldite epoxy resin 6004 and the second part being an Araldite hardener 956, wherein the proportion of resin to hardener is to l.

The finally assembled ferromagnetic structure 12 shown in FIG. 2 is comprised of a bottom member 42, upwardly extending

side members

44 and 46, and

top members

48 and 50 which have their open faced ends 52 and 54 extending toward each other and forming the pole faces for the structure when the coils are energized. Top member 48 includes a top surface 56 and adjacent respective first and

second side surfaces

58 and 60. Similarly top member 50 includes a top surface 62 and adjacent respective first and

second side surfaces

64 and 66. Pole face 54 is in a plane approximately perpendicular to top surface 62 and

side surfaces

64 and 66 of top member 50, while pole face 52 is in a plane approximately perpendicular to

side surfaces

58 and 60 and at an acute angle with top surface 56 of member 48. Pole face 52 is at an angle of approximately 45 with top surface 56, in this instance, but this angle may vary depending upon physical and magnetic requirements of structure 12. Also pole faces 52 and 54 define an air gap therebetween such that the closest portions of the pole faces in this instance are spaced approximately 0.2 inches apart.

At this point it should be noted that while pole face 54in FIG. 2 is shown to be perpendicular to the top and side surfaces of top member 50, alternatively, as shown in FIG. 3, top member 50 can instead have a pole face 68 which is similarly perpendicular to side surfaces 64 and 66 and at an acute angle with respect to the plane of top surface 62.

While two separate coils l4 and 16 are shown in this embodiment, they can be replaced by a single coil if so desired. As a matter of fact, in this instance,

electrical terminals

70 and 72 of coil 14 are electrically interconnected in series with

electrical terminals

74 and 76 of coil 16 when there is need for only a single energizing coil. However in those instances when the relay is required to have a latching function coils l4 and 16 are not electrically interconnected, and coil 14 is used as the latching coil while coil 16 is used as the unlatching coil. The coils typically are energized hy a DC power source or from the output of a full wave rectifier bridge which has its input connected to an AC power source and a voltage transient suppresion device. One suitable voltage transient suppression device is a metal oxide varistor such as a GE MOV Type VP varistor sold by the General Electric Company.

After coils l4 and 16 and structure 12 are assembled together, elongated insulative housings 78, 80, 82 and 84 of respective sealed contact switches 18, 20, 22 and 24 are positioned directly against and permanently attached to

top members

48 and 50 adjacent their respective pole faces 52 and 54 using a suitable mechanical fastening means or bonding agent. The housings in this specific illustrative embodiment are formed of glass and the above referred to bonding agents are also suitable for affixing these glass housings to the top and side surfaces of

top members

48 and 50. More specifically, switch 18 is affixed to side surfaces 58 and 64 of respective

top members

48 and 50, switches 20 and 22 being affixed to

top surfaces

56 and 62 of respective

top members

48 and 50, and switch 24 is affixed to side surfaces 60 and 66 of respective

top members

48 and 50. All of the sealed contact switches are of the same construction as that of switch 18 which is shown in FIG. 4, and they are also of the same type and operate in the same manner as the switch described in copending U.S. patent application Ser. No. 345,997 of Robert C. Guichard, filed Mar. 29, l973 and assigned to the Assignee of the present invention. To the extent necessary to understand the present invention, the switches will be briefly described as follows with specific reference to switch 18. Each switch includes first and second respective

magnetic reed members

86 and 88. One end 90 of member 86 is positioned externally of housing 78, and the other end 92 of member 86 is positioned within housing 78. One end 94 of member 88 is positioned extrnally of housing 78, and the other end 96 of member 88 is positioned within housing 78. Innermost ends 92 and 96 of

respective reed members

86 and 88 are overlapping, and when relay coil 14 is deenergized, ends 92 and 96 are spaced apart to define a gap whereby the reed switch is adapted to operate in a normally open contact mode. For optimum performance, overlapping ends 92 and 96 of

respective reed members

86 and 88 are located approximately equidistant between respective pole faces 52 and 54 of structure 12. Furthermore

reed members

86 and 88 are positioned approximately parallel to the plane of the top surfaces of

top members

48 and 50. Each of the switches further includes a contact button 98 attached to reed member 86 adjacent end 92. One end of a spring member 100 is fastened to reed member 88, while the other end of spring member 100 extends beyond end 96 of reed member 88 and has a contact button 102 attached thereto and in juxtaposition with contact button 98. Again for optimum performance, member 86 is positioned closer to the pole faces of structure 12 than is spring 100. While spring 100 is preferably formed of silver, any non-magnetic spring material having similar properties and characteristics can be used.

While switches 18, 20 and 22 are of the normally open mode when coil 14 is deenergized, switch 24 has been converted to the normally closed mode when the coil is deenergized in the following manner. A permanent bar magnet 104 is bonded to housing 84 of switch 24. The bonding agent used to attach magnet 104 to housing 84 can be identical to the bonding agents used to affix the sealed contact switches to structure 12. Bar magnet 104 is so positioned on housing 84 that its north magnetic pole is oriented opposite the south magnetic pole of the electromagnet formed by energized coil 14 and structure 12, while the south magnetic pole of bar magnet 104 is oriented opposite the north magnetic pole of the electromagnet. Thus, in operation when the coil is deenergized, the magnetic flux, which flows from the north magnetic pole to the south magnetic pole of bar magnet 104, passes through the magnetic reed members and provides sufficient force to cause the overlapping ends of the magnetic reed members to be in contact whereby the switch is in the normally closed mode of operation. Upon energization of the relay and the flow of current through coil 14, magnetic flux,

which then flows through the magnetic circuit comprising structure 12 and the magnetic reed members of the sealed contact switches, interacts with the opposing magnetic flux from bar magnet 104. The resultant flux field flowing through the magnetic reed members of 5 sealed contact switch 24 is then insufficient to keep the overlapping ends of the reed members in contact and the sealed switch is biased to the open mode of operation. Upon deenergization of the relay, the magnetic flux flowing through structure 12 collapses, whereby the resultant magnetic flux flowing between the poles of bar magnet 104 and through the magnetic reed members of switch 24 is again sufficient to cause the closing of the sealed contact switch.

At this point it should be noted that switches 18, and 22 can similarly be converted to operate in the normally closed mode by affixing similar bar magnets to their respective housings. For optimum performance, sealed contact switches 18 and 24, which are affixed to the sides of the top members of structure 12, are better strategically located for operation in the normally closed mode than are sealed contact switches 20 and 22. This is so because there is greater magnetic isolation between a bar magnet affixed to the housing of either of sealed contact switches 18 or 24 and their adja- 25 cent sealed switches than is the case if a bar magnet were affixed to the housing of either of sealed contact switches 20 and 22.

After the relay is completely assembled, it is containable in a suitable enclosure of any convenient standard type such as that illustrated in FIG. 7, wherein the terminals of the coils and the external ends of the sealed contact switches are conventionally electrically connected to external terminals 106 of the relay enclosure. The enclosure can actually consist of a plurality of suitable molded plastic parts 108 which are held together by standard fasteners 110.

By extending

top members

48 and 50 towards each other until they define the relatively small gap therebetween, it is easier for the magnetic flux flowing through structure 12 when coil 14 is energized to flow onto the

top surfaces

56 and 62 of

top members

48 and 50 and then through the reed members of sealed contact switches 20 and 22. This results in an increase in inductive reactance and in the efficiency of the relays magnetic circuit. The higher inductive reactance provides for improved filtering of current pulses that are electrically coupled to the winding of the energizing coil from a rectified AC power source.

Furthermore, by providing that the plane of at least one pole face is at an acute angle with the top surface of its respective top member, some of the magnetic lines of flux flowing through structure 12, when the coil is energized, are forced to the side surfaces of the structure, thereby rendering it possible to successfully operate sealed contact switches 18 and 24 on the respective side surfaces of

top members

48 and 50. Therefore, by being able to operate

switches

18 and 24 on the side surfaces of the top members of structure 12, there is an increase in magnetic isolation between adjacent switches when either or both of

switches

18 and 24 are adapted to operate in the normally closed mode. Also it is possible for the width and, in fact, the cross section of structure 12 to be greatly reduced from the dimension previously required to accomodate the same number of sealed contact switches side by side in a single plane. This reduction in the cross section of structure 12 also desirably results in a reduction of the mean turn length of the coils, a lower resistance per turn ratio, more turns per coil, longer length of coil, and ultimately improved dissipation of heat,iall of which result in an improved relay.

Although the invention has been described with reference to specific embodiments thereof, numerous modifications are possible without departing from the invention and it is desirable to cover all modifications falling within the spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A relay comprising:

a. a ferromagnetic structure including a bottom member, first and second side members extending upward from said bottom member, and first and second top members extending toward each other from said side members and defining respective first and second pole faces and a gap therebetween, each of said top members having a top surface and first and second side surfaces, at least said first pole face being at an acute angle with the top surface of said first top member;

b. an energizing coil positioned around a portion of said structure; and

c. a plurality of sealed contact switches directly affixed to the top and at least said first side surfaces of said top members and adjacent said pole faces.

2. A relay according to claim 1, wherein said first pole face is in a plane approximately perpendicular to the side surfaces of said first top member.

3. A relay according to claim 2, wherein said second pole face is in a plane approximately perpendicular to the top and side surfaces of said second top member.

b. a first magnetic reed member having one end ex- I tending within said housing;

c. a first contact fixed adjacent said one end of said first magnetic reed member;

d. a second magnetic reed member having one end extending within said housing and overlapping said one end of said first magnetic reed member;

e. a non-magnetic spring having one end attached to said second magnetic reed member within said housing and another end extending beyond the overlapping ends of the first and second magnetic reed members; and i f. a second contact attached to said other end of said spring, said second contact being in juxtaposition with said first contact.

6. A relay according to claim 5, wherein said magnetic reed members are positioned approximately parallel to the top and side surfaces of said first and second top members.

7. A relay according to claim 5, wherein the overlapping ends of said magnetic reed members are positioned approximately equidistant between said respective first and second pole faces.

8. A relay according to claim 5, wherein said first in a normally closed mode when said coil is deenermagnetic reed member is positioned closer to said top gized members than is q Spring 10. A relay according to claim 9, wherein said one of 9. A relay according to claim 5, further comprising a bar magnet attached to a portion of the Surface of said switches is attached to either of the first and sec- Said housing f at least one f Said Sealed Contact 0nd side surfaces of said first and second top members. switches, whereby said one switch is adapted to operate

Claims

1. A relay comprising: a. a ferromagnetic structure including a bottom member, first and second side members extending upward from said bottom member, and first and second top members extending toward each other from said side members and defining respective first and second pole faces and a gap therebetween, each of said top members having a top surface and first and second side surfaces, at least said first pole face being at an acute angle with the top surface of said first top member; b. an energizing coil positioned around a portion of said structure; and c. a plurality of sealed contact switches directly affixed to the top and at least said first side surfaces of said top members and adjacent said pole faces.

4. A relay according to claim 2, wherein said second pole face is in a plane approximately perpendicular to the side surfaces and at an acute angle with the top surface of said second top member.

5. A relay according to claim 1, wherein each of said sealed contact switches is further comprised of: a. an electrically insulating housing; b. a first magnetic reed member having one end extending within said housing; c. a first contact fixed adjacent said one end of said first magnetic reed member; d. a second magnetic reed member having one end extending within said housing and overlapping said one end of said first magnetic reed member; e. a non-magnetic spring having one end attached to said second magnetic reed member within said housing and another end extending beyond the overlapping ends of the first and second magnetic reed members; and f. a second contact attached to said other end of said spring, said second contact being in juxtaposition with said first contact.

8. A relay according to claim 5, wherein said first magnetic reed member is positioned closer to said top members than is said spring.

9. A relay according to claim 5, further comprising a bar magnet attached to a portion of the surface of said housing of at least one of said sealed contact switches, whereby said one switch is adapted to operate in a normally closed mode when said coil is deenergized.

10. A relay according to claim 9, wherein said one of said switches is attached to either of the first and second side surfaces of said first and second top members.