US3593231A

US3593231A - Convertible sealed reed switch relay

Info

Publication number: US3593231A
Application number: US601693A
Authority: US
Inventors: Lawrence E Van Horn; Edward Wayne Hart
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1966-12-14
Filing date: 1966-12-14
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13
Also published as: GB1160342A

Abstract

1. A convertible electromagnetic switching device comprising, in combination; a hollow insulating enclosing case; an electromagnet mounted within said case, said electromagnet including a coil having an axial opening therethrough, a magnetizable core extending through said axial opening, and a pair of magnetizable pole pieces overlapping the respective ends of said coil and said core and extending toward each other along opposite external sides of said coil; at least one opening in said case adapted to receive at least one magnetically operable-sealed switch means therein; at least one of said switch means removably inserted into said opening in said case to extend alongside of said magnetizable pole pieces at the opposite external sides of said coil of said electromagnet within said case to be operated upon energization of said electromagnet; and wherein said switch means inserted into said opening in said case comprises a magnetically operable-sealed reed switch unit mounted within an insulating housing to form a switch module, said housing having an external shape to be received by said opening in said case, a pair of wiring terminals secured to said housing to be accessible to the exterior of said enclosing case when said switch module is inserted into said opening therein, and means connecting the current carrying members of said reed switch unit to said pair of wiring terminals.

Description

United States Patent [72] Inventors Lawrence EJ/an Horn Weukesha; it Edward Wayne "in, Milwaukee. both 01, Wis. 1211 Appl. No. 601,693 [22] Filed Dec. 14.1966 [45] Patented July 13.1971 [73] Assignee CutIer-HammerJnc.

Mllwaultee,Wls.

($41 CONVERTIBLE SEALED REED SWITCH RELAY 15 Claims, 10 Drawing Pk:-

[52] 335/151, 317/101, 317l107,317/123 [51] 1nt.Cl 1101111/66, l-lOlh 9/08 [50] 200/167; 335/73,151,152,153,154,162,197,17, 209, 220,81-86, 132, 80;317/123, 101 CB, 101, 156', 340/376; 336/107 [5 6 I References Cited UNITED STATES PATENTS 2,444,476 7/1948 Steam 340/376 X 2,902,558 9/1959 Peek,1r.. 335/152 2,985,733 5/1961 Kamps.............. 335/202 3,002,066 9/1961 Ketchledge et al.. 89/ 140 3,131,331 4/1964 Ray 317/123 3,188,424 6/1965 Else et al. 335/152 3,190,985 6/1965 Pearse et a1 335/152 X 3,234,738 11/1966 Zerfass 335/152 3,359,395 12/1967 Bruce 335/152 X 3,121,147 2/1964 DalBianeoetal... 335/151 3,359,463 12/1967 317/123 Primary Examiner-George Harris Assistant Examiner-R. N. Envall Attorney-Hugh R. Rather CLAIM: I. A convertible electromagnetic switching device comprising, in combination; a hollow insulating enclosing case; an electromagnet mounted within said case, said electromagnet including a coil having an axial opening therethrough, a magnetizable core extending through said axial opening, and a pair of magnetizable pole pieces overlapping the respective ends of said coil and said core and extending toward each other along opposite external sides of said coil; at least one opening in said case adapted to receive at least one magnetically operable-sealed switch means therein; at least one of said switch means removably inserted into said opening in said case to extend alongside of said magnetizable pole pieces at the opposite external sides of said coil of said electromagnet within said case to be operated upon energization of said electromagnet; and wherein said switch means inserted into said opening in said case comprises a magnetically operable-sealed reed switch unit mounted within an insulating housing to form a switch module, said housing having an external shape to be received by said opening in said case, a pair of wiring terminals secured to said housing to be accessible to the exterior of said enclosing case when said switch module is inserted into said opening therein, and means connecting the current carrying members of said reed switch unit to said pair of wiring terminals.

A 1, Ill/I I II PATENTEU JUL 1 3 IBM SHEET 1 IF 5 LLJ PATENTEH JUL 1 3 mr.

SHEET 2 BF 5 an 3 QM wv w v on N. i 3 n M 1 v v w m I W E N. 5 a E: W\ Q m 1 um m 1 m w m I 9 L v Q Q .\N \W Q 00W MQ\ & Q wm\ am 3% Q a? Q3 mm N vv um mm 8 M Q 9v wm vm w mm L A a QM PATENTEU JUN 31% SHEET 3 PF 5 PATENTEU JUL 1 3 I97? SHEET BF 5 lllli ll NN 3v mm N S PATENTED JUL 1 3197i SHEET S BF 5 CONVERTIBLE SEALED REED SWITCH RELAY This invention relates to electromagnetically operated relays and more particularly to such relays which utilize sealed reed switches to make and break the circuits.

While not limited thereto the relay of this invention is particularly suitable for industrial control applications such as on machine tools and other types of machinery.

The numerous advantages of sealed reed switches render them extremely desirable in design approaches of such relays where the present demands call for reduced size and greater life and reliability. The present relay incorporates standards and conventions accorded the prior art machine tool relays and in so doing, has various features which are unique to reed relay constructions.

It is therefore a primary object of this invention to provide an electromagnetic relay designed for industrial control applications which utilizes sealed reed switches as the switching pole elements.

It is another object of this invention to provide an electromagnetic relay of the sealed reed switch type wherein the reed switch poles are located externally of the coil and a laminated steel core is located with in the central opening of the coil.

It is another object of this invention to provide an electromagnetic relay of sealed reed switch application having modular construction wherein the individual reed switch poles may be read y replaced in the field.

It is another object of this invention to provide an electromagnetic relay of the sealed reed switch type which requires a minimal panel area for mounting and has from accessibility for removing the switch poles and for the wiring terminals.

It is further object of this invention to provide an electromagnetic reed relay which may be of standard or latched type operation wherein the reed switch pole elements may be readily changed from normally open to normally closed, or vice versa.

It is still a further object of this invention to provide an electromagnetic relay capable of operating on either AC or DC supply and wherein a rectifier unit necessary for AC use is readily replaceable.

It is still another object of this invention to provide a read relay having mechanical means to indicate the operational state that the relay is in.

Other objects and advantages will be pointed out in, or be apparent from the following specification and claims when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a front elevational view of the relay of this invention;

FIG. 2 is a cross-sectional view taken along line 2 2 of FIG. 1 showing the general side profile of the relay and the orientation of the switch pole units within the relay;

FIG. 3 is a front elevational view of a modified version of the relay of this invention;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 3;

FIG. 7 is a cross sectional view taken along line 7-7 of FIG.

FIG. 8 is an exploded isometric view of the various parts utilized to make up a coil pole unit;

FIG. 9 is an exploded isometric view of the various parts used to make up a desired switch pole unit; and

FIG. 10 is a circuit diagram of one of the parts shown in the coil pole unit of FIG. 8 and its connections to the coil.

The relay shown in FIGS. l and 2 is a standard relay having normally open and normally closed switch poles operable to their closed and open conditions, respectively. by energizing the coil and returnable to their original conditions upon deenergization of the coil. The relay shown in FIGS. 3 through 7 is a latched type of relay also having both types of switch poles. but all of which require energization of a second coil, wound in a reverse direction, to return the switches to their original conditions. The standard and latched relays are physically quite similar with only minor detail differences to the base, coil and one of the magnetic pole pieces. These differences will be specifically mentioned in the following description while for the most part the description will be applicable to both versions.

The relay has an enclosing case, or boxlike base 2, made of a plastic insulating material with a central cavity open to the front and rear. a central web extends across the front opening between the sidewalls to form a front wall 2a which divides the opening into upper and lower switch pole receiving openings. Each of these openings is divided into four separate switch pole receiving pockets by ribs 2b which extend along the side and rear walls of the base. A central opening 2: is provided in the rear wall of base 2 which is of corresponding size and alignment with the front wall 20. Opening 2c also extends into the portion of the rear wall which is in corresponding alignment with the upper right-hand switch pole receiving pocket for the standard relay of FIG. 1 and extends into the portions of the rear wall which are in alignment with both the upper and lower right-hand switch pole receiving pockets of the latched relay of FIG. 3. The base 2 is also provided with a pair of inwardly projecting ribs in! (FIGS. 6 and 7) which extend along one sidewall from the opening 2c to the inner surface of the front wall 20. The front wall 20 has a window 2: formed therein, one edge of which lies adjacent one of the sidewalls of the base 2, and a transparent plastic lens If is secured over the window 2: by any suitable method, such as glueing. In addition, the wall 20 has a centrally located threaded opening 23 and a plurality of various shaped recesses along its upper and lower edges, each recess being in alignment with a pole receiving pocket. The shape of the recesses provide keyways to prevent the insertion of an improper pole unit into the respective pocket. Each of the keyways is further provided with a threaded opening in its bottom surface to receive a screw held by the pole unit to secure the unit within the pocket as will become more apparent in later description. It may be seen by comparing FIGS. 1 and 3 that the keyway arrangement varies between the standard and latched relay as will become more apparent in later description.

A first U-shaped pole piece 4 is inserted, bight portion first, into base 2 through opening 2: until such portion thereof engages the inner surface of front wall 20. The bight portion is cut back somewhat at one end to clear the ribs 2d while the legs thereof engage the opposed outer sides of the ribs to position the pole piece within the base. The bight portion of pole piece 4 is also cut back at the opposite end to provide travel clearance for an indicator member as will be more fully described later. Each leg of pole piece 4 is divided by slots 44 into four individual legs, each of which are in alignment with a respective pole receiving pocket.

A molded coil-element 6 is next inserted through opening 2c until the end thereof bears against the bight of pole piece 4. The coil is provided at the rear most end with a foot portion 60 (see FIGS. 5, 6 and'l) which extends to one side to lie within the opening of the upper right-hand pocket of base 2 for the standard relay. An additional, oppositely extending foot 6b is provided for the latching relay, the foot 6b extending into the opening of the lower right-hand pocket of base 2. The coil for the standard relay has a single coil winding 6c, the ends of which are connected internally to the male halves of a pair of plug-in type connectors M which extend upwardly from foot 60. The coil 6 for the latching relay is a double-coil element having a somewhat smaller "operate" winding 6: connected internally to the male connectors 6d of foot 60, and a "release" winding 6] wound in the opposite direction of the operate winding, the ends of which are connnected to male connectors 63 extending upwardly from foot 6b. Each foot 6a and 61) has a slot 6h molded into its upper surface between the upstanding prong members.

The coil 6 is an elongated member with a central opening extending from end to end. A core is provided for the coil 6 by inserting a loose stack of steel laminations 8 into the central opening from the rear of the relay. The length of the lamina tions is just slightly greater than the length of the coil so that the laminations bear against the bights of pole piece 4 and a second pole piece 10 which is inserted over the rear end of coil 6.

Pole piece I is a U-shaped member similar to pole piece 4 and is inserted into the relay with its legs entering first to extend along the coil 6 toward the rearwardly extending legs of pole piece 4. The bight of pole piece I0 is also cut back at one end to clear the positioning ribs 2d while its legs engage the opposed outer sides of the ribs to position the member. The legs of pole piece 10 are divided by slots 10a into four individual legs which are aligned with the legs of pole piece 4. The other end of pole piece 10 is cut away at one side thereof to clear the foot 60 of coil 6 for the standard relay and cut away straight across the end to clear both

feet

60 and 6b of the latching relay. With particular reference to FIG. 4 it can be seen that in cutting away the end of pole piece I0 to clear the

feet

6a and 6b of coil 6, the right-hand individual legs thereof have also been removed. In the standard relay where it is only necessary to provide clearance for the foot 6a, only the upper right-hand individual leg member is removed. It can also be seen that the center pair of legs of each pole piece are somewhat shorter than the end legs thereof so that in their assembled positions within the cavity the airgap between the cooperating center legs is greater than the gap between the cooperating pairs of outer legs. This produces a more even flux density within each pole pocket, while slotting the pole piece legs into individual legs concentrates the flux within the pole pocket areas and decreases the eddy currents of the pole pieces 4 and 10 to provide a faster pickup and dropout time for the switch poles.

The coil and pole piece assembly is held fast within the base by placing a leaf spring l2 against the pole piece 10 and securing the base to a mounting plate I4 by rivets 16 which are received within openings in a plurality of feet 2/: on base 2. Mounting plate I4 has an arrangement of holes therein for mounting the relay to a panel. The central portion of spring 12 engages the pole piece I0 and is positioned by a pair of depending bosses [0b on the pole piece [0 which inter'fit with corresponding notches formed on the edges of spring 12. The outer ends of spring 12 are bent away from the pole piece [0 to engage the plate l4. Upon assembly of the plate 14 to the enclosing case, or base 2, the spring 12 is compressed between the plate and the pole piece 10 to bias the electromagnet assem bly tightly against the web, or front wall 20.

Base 2 is also provided with a mechanical indicator assembly (see FIG. which consists ofa long spring member 18 having a tab formed at one end by bending a portion of the end at right angles to the member I8. The spring 18 has a mounting portion 18a formed at its other end consisting of a pair of wings extending angularly and transversely to the spring member. The portion 18a is forced within a linear slot 2k in the rear end of one of the sidewalls of base 2 to secure that end to the base by compressing the wings flat so that the spring 18 extends along the wall and into the window 2e. The tab of spring 18 receives a colored plastic sleeve 18b to provide an easily visible indicator through the lens 2]. The spring 18 also has a strip of magnetizable material 1&- secured to its central portion to serve as an armature which is attracted to the cut back bight of pole piece 4 upon energization of the coil 6, thereby moving the colored indicator 18b to the left-hand position within the window 2e to indicate the energized state of the relay. The spring member I8 returns the indicator 18b back to the original right-hand position in window 22 upon deenergization of coil 6. The strip 180 is replaced by a permanent magnet member of similar dimensions in the latching relay which causes the indicator to remain in the left-hand position in response to an operating pulse and be released to the right-hand position in response to a reversely directed pulse by the release winding.

As so far described the relay is a factory assembled device comprising the enclosing case an electromagnet assembly which is purchased as a unit with individual switch and rectifier modular elements assembled thereto. These elements may also be individually purchased to replace or be added as desired within certain limits as set forth by the keyway combinations of the front surface 2a of the base. The electromagnet assembly within the enclosing case divides the central cavity into two individual cavities, each aligned with the respective front opening on either side of the central web 20 to receive the various modular elements. The standard relay (FIG. 1) requires one coil pole module CP and has provisions for seven switch pole modules of either the normally open type NO or the normally closed type NC with a limit of five normally closed modules. The latched relay (FIG. 3) requires two coil pole modules and has provisions for six switch pole modules of either the normally open latched type N01. or the normally closed latched type NCL with no limits as to either type.

With reference to FIG. 8, the various parts used to make either of two types of coil pole modules are shown in exploded isometric relation. The coil pole module CP consists of a pair of

complemental housing halves

20 and 22, which are generally symmetrical externally, and a barrier member 24 which is sandwiched between the housing halves at their lower end. The housing halves 20 and 22 and barrier 24 are made of an insulating plastic material. The inside faces of

members

20 and 22 and opposite faces of barrier 24 are formed with numerous interfitting and complemental bosses and recesses to position and trap the current carrying elements according to conventional manufacturing techniques, therefor such positioning will only briefly be described.

A pair of female stab-on

connectors

26 and 28 are provided with notches 26a and 280, respectively, in each leg of their U- shaped body portions. The connector 26 is entrapped between the housing half 20 and the barrier 24 with its bight portion abutting a ridge 20a on housing half 20 and the notches 26a intert'itting with a complementally formed boss 20b on housing 20 and a similar boss on barrier 24. Likewise, connector 28 is entrapped between barrier 24 and housing half 22 with its bight portion against a ridge 240 formed on barrier 24 and its notches 28a engaging a complementally formed boss 24b on barrier 24 and a similar boss on housing 22. To position the barrier 24 within the

housings

20 and 22, the barrier is provided with a T-shaped lateral extension 24c, the crosshead of which fits snugly into respective grooves in the housing members. The barrier 24 is also provided with a tapered leg 24d which depends beyond the lower ends of the housing members.

A pair of substantially L-shaped screw receiving

terminal plates

30 and 32 are each provided with a notch and wing configuration along their edges to interfit with complementally shaped ledges and recesses in the

housing halves

20 and 22 and be entrapped therebetween with the screw receiving portions extending outwardly of the housings. Each of the

housing halves

20 and 22 have one half of a key formation at their upper ends, each half of the key being provided with a semicircular opening which becomes a circular hole upon assembly of the two halves. A screw having a reduced shank diameter is rotatably captivated within the opening to be threaded into the corresponding opening within the keyway upon insertion of the unit into the pocket. The key for the coil pole unit, when assembled, is substantially the male portion ofa dovetail arrangement which will only fit into a correspondingly dovetailed keyway in the base 2.

The housing halves, with the various parts held therebetween, are preferably secured together by sonic welding. Each

housing half

20 and 22 also has a stepped recess 20: and 22c, respectively, along the lower portion of their mating edge (FIG. 8) which forms a secondary keyway for the coil pole module when the halves are assembled. The secondary keyway for the coil pole module when the halves are assembled. The secondary keyway surrounds a complemental ridge, or key, 2j in the coil pole receiving pocket of base 2 to allow that module to be fully inserted therein (FIGS. 5 and 7). The switch pole modules, to be described later. do not have the secondary keyway formed therein and therefore abut the top edge of the ridge 2j to prevent their complete insertion into a pocket designed to receive a coil pole module.

Electromagnetic relay coils generally require a direct cur rent input to operate at a steady value. particularly relays of the reed switch type. If the supply current to the relay is to be DC, a DC coil pole module is provided by soldering a first conductor between terminal 30 and connector 26 and another conductor between terminal 32 and connector 28. The coil pole module is then inserted into the base until thefirst, or upper. key seats with the mating keyway and is held there by turning the captivated screw into the corresponding threaded opening in the keyway. When the coil pole CP is so inserted the

female connectors

26 and 28 engage the respective prong terminals of the coil to provide electrical connection therebetween and the

terminals

30 and 32 receive pressure plates and binding screws to secure conductor leads from the supply source. The tapered leg 24d of the barrier 24 extends down into the groove 6] to provide additional insulation between the prong and blade connections to the coil.

For the installation where the supply current to the relaywis to be AC, a rectifier package 34 is added to the coil pole module. The barrier 24 has a pocket 24c open to its upper end which receives a projection 340 depending from the rectifier package to position the latter within the housings. The housing halves and 22 also have ledges which overhang the package 34 to further entrap the package therebetwecn. The wire leads of the rectifier package 34 are in turn welded tothe various terminals in the manner shown in the circuit diagram of FIG. [0. The

wiring terminals

30 and 32 are connected to the input terminals of a full wave rectifier bridge RE. the output terminals of which are connected to the

connectors

26 and 28. A zener diode ZD is connected in series between an output terminal of bridge RB and the terminal 16 and is poled to oppose the current direction to effectively brake the induced current flow upon deenergization to provide a faster dropout time for the relay. The elements of the package 34 may be molded in epoxy resin or the like to the proper shape so that the package may be easily assembled in the coil pole module. Providing the coil rectifier in a separate, removable unit such as the coil pole CP is a definite advantage to the customer as it has been found that the source of coil faults are commonly failure ofa rectifier. Upon such a failure, the customer need only replace the coil pole module instead of the entire coil, which is a much simpler and less expensive operation.

The various switch pole modules that are used for the two types of relays are physically very similar. The parts shown in the exploded isometric view of HG 9 represent the parts which may be used to make any of the required polar. Each switch pole module is made up of two

housing halves

40 and 42. the exterior shapes of which are very similar to the

housing halves

20 and 22. The housings have notches 40a and 424 formed in one wall to form a window. when assembled, to expose a sealed reed switch unit 44 positioned inside. The reed switch units shown in the drawings are merely exemplary of a type of reed switch to be used. A particular reed switch of the type described and claimed in the .I. A. Bongard and MR. Swinehart copending application Ser. No. 528,240, now US. Patv No. 3.327.262 and assigned to the assignee of this invention. has been found to be desirable for use in the relay disclosed herein.

A screw receiving wiring terminal 46 is secured to one of the extending reeds of switch unit 44, and the other extending reed thereof has a conducting strap 48 secured to it to extend along the reed switch to a point just below the terminal 46 where a second wiring terminal 50 is secured to the strap 48.

The

terminals

46 and 50 are similar to the

terminals

32 and 30. respectively, and similarly intertit within the

housing halves

40 and 42 to secure the upper end of reed switch 48 in place. An insulating sleeve 38. of rubber, heat shrinkable material. or the like, is disposed around the upper end of the reed switch to surround the exposed portion of the reed between the glass enclosure and the terminal 46. A similar sleeve may be added to the lower end of the switch if the usage of the device requires additional insulating qualities. A slot such as at 42b (FIG. 9) is provided in each housing half to receive the extending end of the lower reed to thereby position the lower end of the switch within the housing. A leaf spring 52 is entrapped within grooves of the housings to extend outwardly of one side of the switch pole unit to bear against the sidewall of base 2 upon insertion of the switch pole module into the base. the spring 52 thereby urging the lower, or inner. end of the module into close proximity with pole piece 10.

The switch pole module as herein described is a normally open switch and is secured together by sonic welding. as was the coil pole module, and similarly has a screw captivated in the key formed at the upper end of the housing. The key for the normally open switch pole unit when assembled is a semicircular one as shown in dotted lines in the lower row of pole units of FIG. 1, and is received by any of the three types of keyways of the base 2. However, as mentioned earlier. the secondary key 2j of the coil pole pockets prevents the insertion of the NO switch module therein. The normally open switch module is shown in its assembled position with respect to the base 2 in the lower portion of FIG. 2.

With further reference to FIG. 9, a biasing permanent magnet assembly 54 may be added to the aforedescribed switch pole module to achieve either a normally closed. normally open latched. or normally closed latched switch pole version. Magnet assembly 54 comprises a pair of

permanentmagnets

56 and 58 secured to a steel strap 60 and positioned within pockets 40c and 42c of

housing halves

40 and 42, respectively, to lie along side of the glass enclosure of the reed switch and on the side thereof opposite to the coil. The different operating modes are achieved by poling the bias magnet assembly 54 in different directions and by different choices of permanent magnet materials which produce different flux output levels.

To provide a normally closed switch pole module NC, the magnet assembly 54 is poled to provide a flux path within the reed switch unit 44 that will be opposite in direction to the flux path of the "operate" coil 6c within the reed switch when the module is inserted into the relay base. The magnet assembly 54 for the normally closed version is made of

magnets

56 and 58 which are made from Alnico 8 or the like to produce a flux of sufficient strength to operate the reeds of switch unit 44 of its own accord, and therefor the fluLOf the assembly 54 must be cancelled by the flux of the operate" coil upon energization thereof to cause the reeds to drop open.

To provide a normally open latched switch pole module NOL, the magnet assembly 54 is poled to provide a flux path within the reed switch 44 that will be in the same direction as that provided by the operate" coil 6:. In this instance the magnet assembly 54 has

magnets

56 and 58 constructed of Alnico 5 or the like to produce a flux of a strength which is not sufficient to operate the reed switch of its own accord. but is sufficient to hold the reeds closed once they are operated by the energized "operate" coil 6e. The release" coil 6fcreates an opposing flux path within the switch unit 44 upon energization to effectively cancel the flux of the biasing magnet assembly therein to cause the reeds to open.

To provide a normally closed latched switch pole module NCL. the magnet assembly 54 is poled to provide a flux path within the reed switch unit which is opposite to that provided therein by the energized operate coil. In this instance. the magnet assembly 54 again uses

magnets

56 and 58 made from Alnico 5 or the like to-produce a flux of insufficient strength to operate the switch reeds of its own accord. but is of sufficient strength to hold them closed when they are operated by the relay coil. The switch 44 is initially closed in this version after insertion into the relay base by pulsing the "release" coil 6f which provides a flux path within the switch which cooperates with that ofthe biasing magnet assembly 54, and the two paths add to provide sufficient magnetic strength to close the reeds. The flux provided by the energized "operate" coil is opposite to that of the permanent magnet assembly 54 and cancels the biasing flux to open the contacts.

In each switch pole module where the biasing magnet assembly 54 is employed it is necessary to provide a magnetic shield for the unit to prevent stray flux patterns from affecting adjacent switch units. To this end, a pair of thin steel straps 62 are secured within

recesses

40d and 42d formed in the exterior surfaces of

housings

40 and 42, respectively, by riveting over projections 40: formed on the housing 40 and which are received by holes 62a of strap 62. While only one strap 62 is shown in FIG. 9 for representative purposes, it is to be understood that a shielded switch module has two straps 62, one for each housing half as can be seen in the cross-sectional view of FIG. 7. The key portion for each switch pole module having the biasing magnet assembly 54 is substantially a triangular member as shown in dotted lines in the upper row of pole modules in FIG. I, and will fit only in the triangular keyways of base 2, thereby controlling the number and location of the biased pole modules with respect to the standard relay of FIG. 1.

A plastic dummy pole member 64 is provided to be used in pockets not requiring a switch module and is shown in one of the pockets of the latched relay, particularly FIGS. 3 and 5. Member 64 is somewhat similarly shaped to the upper halfofa switch or coil pole module, having a semicircular key which is received by any of the keyways. A boss 64a depends from the key to extend into the threaded opening of the keyway to help position the upper end of the member. The lower end of member 64 extends just slightly into the pocket to position the lower end thereof.

A cover plate 66 is placed over the front of the relay and secured in place by a screw which takes into the central threaded opening 2g of base 2. The plate 66 overlies all of the keyways of base 2 to cover the screws holding the switch pole modules down and bears inwardly against a portion of the dummy pole 64 to further hold it in place and to prevent is accidental removal. An opening is provided in plate 66 to allow the lens 2fto extend therethrough and suitable inditia may be provided on the cover plate adjacent the lens opening to aug ment the indicator member 18b.

The extensive use of plastic throughout the relay allows the various parts to be easily and inexpensively colored to provide a color coding to depict the functions of the various parts. As a preferred example, the base is colored gray in keeping with most electrical equipment enclosures and cases today. The enclosing case, or base 2, of the standard relay is a darker gray, such as charcoal, than is the base of the latched relay. The coil

pole module housings

20 and 22 are colored blue for the strictly DC coil pole, while the AC-DC pole module housings are colored red. The switch pole modules are also colored according to function, the normally open pole module NO having

green housing halves

40 and 42, the normally closed pole module NC having yellow housing halves. For latched poles NOL and NCL, one of the housing halves is light gray as is the base while the other housing half is either green for the normally open or yellow for the normally closed.

Thus there is provided a panel mounted sealed reed switch relay of unitized construction, the parts of which may be readily replaced to vary the operating mode or replace a defective unit. It is to be understood that the aforedescribed relay is merely exemplary of one preferred construction and is not intended to limit the scope of the appended claims.

We claim:

1. A convertible electromagnetic switching device comprising, in combination; a hollow insulating enclosing case; an electromagnet mounted within said case, said electromagnet including a coil having an axial opening therethrough, a magnetizable core extending through said axial opening, and a pair of magnetizable pole pieces overlapping the respective ends of said coil and said core and extending toward each other along opposite external sides of said coil; at least one opening in said case adapted to receive at least one magnetically operablesealed switch means therein; at least one of said switch means removably inserted into said opening in said case to extend alongside of said magnetizable pole pieces at the opposite external sides of said coil of said electromagnet within said case to be operated upon energization of said electromagnet; and wherein said switch means inserted into said opening in said case comprises a magnetically operable sealed reed switch unit mounted within an insulating housing to form a switch module, said housing having an external shape to be received by said opening in said case, a pair of wiring terminals secured to said housing to be accessible to the exterior of said enclosing case when said switch module is inserted into said opening therein, and means connecting the current carrying members of said reed switch unit to said pair of wiring terminals.

2. The combination according to claim 1 together with permanent magnet means secured within the housing of said switch module adjacent said switch unit and on a side thereof opposite said electromagnet when said module is inserted in said opening in said enclosing case, and wherein said permanent magnet means produces a magnetic flux path within said switch unit to bias the magnetically operable contacts thereof.

3. The combination according to claim I together with a connector module inserted into said opening in said case to provide a readily removable electrical connection to said electromagnet, plugin electrical connector means mounted on said coil and cooperating plug-in electrical connector means mounted on said connector module in engagement with said connector means on said coil, a pair of wiring terminals secured to said connector module to be accessible to the exterior of said enclosing case when said connector module is inserted into said opening therein, said connector module having an outwardly extending key formed thereon to be cooperatively received within a complementally formed recessed keyway in said case, and having a secondary keyway formed therein to cooperate with an outwardly extending secondary key formed in said enclosing case, said secondary key being of a form preventing insertion of said switch modules therein.

4. The combination according to claim 2 together with a pair of shallow recesses formed in opposite external sides of those switch module housings in which permanent magnets are mounted, projections extending outwardly from said recesses and a pair of magnetizable members secured within said recesses at opposite external sides of said switch module housings by deforming said projections over outer surfaces of said magnetizable members to provide self-contained mag netic shielding for each switch module.

5. The combination according to claim I wherein said insulating housing of said switch module has a lateral opening formed therein on the side adjacent said pole pieces of said electromagnet to expose a portion of said switch unit directly to said electromagnet.

6. An electromagnetically operated multipole convertible reed relay comprising, in combination; a hollow insulating enclosing case; a coil mounted in said case to extend axially front to rear of said case; an axial opening in said coil; a magnetizable core in said opening in said coil and extending end-to-end of said coil; a pair of U-shaped magnetizable pole pieces overlapping the opposite ends of said coil and extending toward each other along the opposite exterior sides of said coil; openings in the front of said enclosing case on opposite sides of said coil; and a plurality of individually removable switch modules inserted within said openings in said case to extend into said case alongside of said pole pieces at the exterior sides of said coil, each of said switch modules comprising a molded insulating housing, a sealed electromagnetically operable reed switch mounted within said housing, a pair of wiring terminals carried by said housing at a forward end to extend out of said enclosing case. and means connecting said wiring terminals in the respective contacts of the reed switch mounted within the housing I The combination according to claim 6 wherein the insu lating housing of each of said switch modules has a lateral opening formed therein on the side ad acent said pole pieces of said electromagnet to expose a portion of said reed switch unit directly to said electromagnet 8. The combination according to claim 6. together with an indicator member mounted within said case to extend along one side of said electromagnet and into a window formed in an exterior surface of said case, said indicator being movable toward and away from said electromagnet. means to bias said indicator away from said electromagnet to a first position within said window, and wherein said indicator is attracted to said electromagnet upon energization thereof to cause said indicator to move to a second position within said window 9. The combination according to claim 6. wherein the winding ends of said coil are terminated at plug-in type electrical connector means, first portions of said connector means being secured to an exterior surface of said coil and exposed within one of said pockets of said case, second cooperating portions of said connector means secured to an insulating housing removable inserted into said pocket, said housing further having a pair of wiring terminals secured thereto exposed to the exterior of said case when said housing is seated within said pocket, and conductor means electrically connecting said other portions of said connector means to said wiring terminals within said housing.

Ill. The combination according to claim 9, wherein said conductor means comprises rectifier means for rectifying supply alternating current to provide energizing direct current for said coil, said rectifier having its input terminals connected to said wiring terminals and its output terminals connected to said second cooperating portions of said connector means.

II. The combination according to claim 10, wherein said rectifier means is a full-wave rectifier bridge and further comprises a zener diode connected between an output terminal of said rectifier bridge and the associated other portion of said connector means to be in series with said coil and oppose the coil current when electrically connected thereto.

12. The combination according to claim 6, wherein said core comprises a plurality of magnetizable laminations loosely stacked within the central opening of said coil.

13. [n a convertible electromagnetic switching device, the combination comprising:

an insulating enclosing case having a cavity with openings to opposite ends thereof, a central web extending across a first open end of said case to divide the opening therein into a pair of openings. and a pair of inwardly extending wall portions at the second open end of said case to reduce the opening therein;

a first magnetic pole piece inserted within said cavity from said second end to abut said central web and having portions extending toward said second end;

a coil member inserted within said cavity from said second end to abut said first pole piece between said extending portions, a central opening in said coil member aligned with said opening in said second end of said case and extending through said coil to open to said first pole piece; and at least one foot portion extending outwardly of said coil member, said foot portion having plug-in electrical connectormeans secured to an exterior surface thereof and connected to the windings of said coil, said connector means being in alignment with a respective one of said pair of openings of said case and within said cavity thereof.

a core comprising a plurality of loosely stacked magnetizable laminations nserted within said central opening of said coil through said opening in said second end of said case. said core abutting said first magnetic pole piece;

a second magnetic pole piece inserted within said cavity from said second end to abut an opposite end of said core, said second magnetic pole piece aving portions extending along opposite sides of said coil toward said extending portions of said first pole piece and in alignment therewith.

a mounting plate for mounting said switch device to a panel secured to said second end of said enclosing case to close the opening therein;

biasing means disposed within said opening in said second end. said biasing means being compressed between said mounting plate and said second magnetic pole piece to bias said magnetic pole pieces. core and coil tightly against said central web within said cavity;

means removably inserted into said cavity through a respective one of said openings in said first end to cooperatively engage said connector means for electrically connecting said coil winding to an energizing supply source; and

least one magnetically operable switch module removably inserted into said cavity through either of said openings in said first end to be operated upon energization of said coil.

14. In combination, an operating coil for an electromagnetically operable switching device and a plug-in connector module for connecting said coil to an electrical supply source, said coil having plug-in electrical termination means exposed to an exterior surface thereof and said connector module including an insulating housing, plug-in connector means supported on said housing, wiring terminal means supported on said housing, and a full wave rectifier bridge within said housing, said bridge having its input terminals connected to said wiring terminal means and its output terminals connected to said plug-in connector means, and wherein an electrical supply source is connected to said wiring terminals on said connector module and the latter is connected to said coil by means of cooperable plug-in engagement between said plug-in connector means on said module and said plug-in termination means on said coil to supply rectified current to said coil.

15. A convertible electromagnetic switching device com prising in combination; a hollow insulating enclosing case; an electromagnet mounted within said case, said electromagnet including a coil having an axial opening therethrough, a magnetizable core extending through said axial opening and a pair of magnetizable pole pieces overlapping the respective ends of said coil and said core and extending toward each other along opposite external sides of said coil; at least one opening in said case adapted to receive at least one magnetically operable sealed switch means therein, at least one of said switch means removably inserted into said opening in said case to extend alongside of said magnetizable pole pieces at the opposite external sides of said coil of said electromagnet within said case to be operated upon energization of said electromagnet, and an indicator member mounted within said case alongside said electromagnet for removing toward and away from said electromagnet, said indicator member having a portion extending beyond said electromagnet and into a window opening formed in said case, means for biasing said indicator member to a first position within said window, and wherein said indicator is attracted to said electromagnet upon energization thereof to cause said portion within said window to move to a second position therein against the bias of said biasing means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 1 Dated July 13, 1971 lnventofls) Lawrence E. Van Horn t a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet [54] "15 Claims" should read 18 Claims Column 1, line 25, "with in" should read within line 36, after "is" insert a Column 3 line 69, after "bight" insert portion Column; 5, lines 2 to 4, cancel "The secondary keyway for the coil pole module when the halves are assembled.". Column 7, line 43, "is" should read its Column 9, line 24, "removable" should read removably Column 10, after line 66, insert the following claims:

-16. Ina relay the combination comprising: an

operating coil defining opposite, parallel sides; a

plurality of modular switch units assembled with the coil,

each switch unit comprising an elongated case with a reduced body portion and an enlarged head presenting a pair of forwardly facing terminals which are stepped upwardly from front to rear, each switch unit including an elongated, magnetically operable reed switch disposed in the body portion of the case with one end near the head, there being a connector between said one end of the switch and one of the terminals and a second connector leading from the other end of the switch to the other terminal, which second connector is disposed in the case alongside the EM PO-IOSO (10-69) USCOMM-DC 60376-P69 U.ST GOVERNMENT PRINTING OFFICE: 9'9 D-SlB-JS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 593 Z31 Dated July 13 1971 2 Inventor) Lawrence E. Van Horn 81; 1 PAG It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

switch, switch units being arranged in banks which face respective sides of the coil, each bank comprising a plurality of switch units in an aligned, side-byside relationship, the two banks being in an aligned relationship with the backs of the two banks facing one another and with the heads of the units of both banks all on the same side of the coil but with the heads of the units of the two banks facing outwardly in opposite directions, the switches all being axially aligned with the coil to be operable thereby; and housing means to releasably hold the switch units and coil in assembled relationship,--

)RM F o-1050 (10-69) USCOMM-DC 60376-pqg U.5. GOVERNMENT PRINTING OFFICE I965 CIS66-33| UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 593 231 Dat d July 13 1971 Lawrence E. Van Horn et a1 .PAGE 3 Inventor(s) It is certified that error appears in the above-identified patent and that said Letter s Patent a hgreby corrected as shown below --l7. The combination of claim 16 wherein there are a plurality of aligned pairs of elongated magnetic flux concentrator plates, one pair being adjacent each switch with the members of the pair parallel to and associated with respective reeds to define a magnetic flux path across the magnetic gap of the switch.--

--l8. The combination of claim 17 wherein the pairs of concentrator plates each comprise an upper member at one end of the coil and a lower member at the other end of the coil; and the upper ends of all the upper members are magnetically connected; and the lower ends of all of the lower members are magnetically connected.

Signed and sealed this 23rd day of May 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims

1. A convertible electromagnetic switching device comprising, in combination; a hollow insulating enclosing case; an electromagnet mounted within said case, said electromagnet including a coil having an axial opening therethrough, a magnetizable core extending through said axial opening, and a pair of magnetizable pole pieces overlapping the respective ends of said coil and said core and extending toward each other along opposite external sides of said coil; at least one opening in said case adapted to receive at least one magnetically operable-sealed switch means therein; at least one of said switch means removably inserted into said opening in said case to extend alongside of said magnetizable pole pieces at the opposite external sides of said coil of said electromagnet within said case to be operated upon energization of said electromagnet; and wherein said switch means inserted into said opening in said case comprises a magnetically operable sealed reed switch unit mounted within an insulating housing to form a switch module, said housing having an external shape to be received by said opening in said case, a pair of wiring terminals secured to said housing to be accessible to the exterior of said enclosing case when said switch module is inserted into said opening therein, and means connecting the current carrying members of said reed switch unit to said pair of wiring terminals.

3. The combination according to claim 1 together with a connector module inserted into said opening in said case to provide a readily removable electrical connection to said electromagnet, plug-in electrical connector means mounted on said coil and cooperating plug-in electrical connector means mounted on said connector module in engagement with said connector means on said coil, a pair of wiring terminals secured to said connector module to be accessible to the exterior of said enclosing case when said connector module is inserted into said opening therein, said connector module having an outwardly extending key formed thereon to be cooperatively received within a complementally formed recessed keyway in said case, and having a secondary keyway formed therein to cooperate with an outwardly extending secondary key formed in said enclosing case, said secondary key being of a form preventing insertion of said switch modules therein.

4. The combination according to claim 2 together with a pair of shallow recesses formed in opposite external sides of those switch module housings in which permanent magnets are mounted, projections extending outwardly from said recesses and a pair of magnetizable members secured within said recesses at opposite external sides of said switch module housings by deforming said projections over outer surfaces of said magnetizable members to provide self-contained magnetic shielding for each switch module.

5. The combination according to claim 1 wherein said insulating housing of said switch module has a lateral opening formed therein on the side adjacent said pole pieces of said electromagnet to expose a portion of said switch unit directly to said electromagnet.

6. An electromagnetically operated multipole convertible reed relay comprising, in combination; a hollow insulating enclosing case; a coil mounted in said case to extend axially front to rear of said case; an axial opening in said coil; a magnetizable core in said opening in said coil and extending end-to-end of said coil; a pair of U-shaped magnetizable pole pieces overlapping the opposite ends of said coil and extending toward each other along the opposite exterior sides of said coil; openings in the front of said enclosing case on opposite sides of said coil; and a plurality of individually removable switch modules inserted within said openings in said case to extend into said case alongside of said pole pieces at the exterior sides of said coil, each of said switch modules comprising a molded insulating housing, a sealed electromagnetically operable reed switch mounted within said housing, a pair of wiring terminals carried by said housing at a forward end to extend out of said enclosing case, and means connecting said wiring terminals to the respective contacts of the reed switch mounted within the housing.

7. The combination according to claim 6, wherein the insulating housing of each of said switch modules has a lateral opening formed therein on the side adjacent said pole pieces of said electromagnet to expose a portion of said reed switch unit directly to said electromagnet.

8. The combination according to claim 6, together with an indicator member mounted within said case to extend along one side of said electromagnet and into a window formed in an exterior surface of said case, said indicator being movable toward and away from said electromagnet, means to bias said indicator away from said electromagnet to a first position within said window, and wherein said indicator is attracted to said electromagnet upon energization thereof to cause said indicator to move to a second position within said window.

9. The combination according to claim 6, wherein the winding ends of said coil are terminated at plug-in type electrical connector means, first portions of said connector means being secured to an exterior surface of said coil and exposed within one of said pockets of said case, second cooperating portions of said connector means secured to an insulating housing removable inserted into said pocket, said housing further having a pair of wiring terminals secured thereto exposed to the exterior of said case when said housing is seated within said pocket, and conductor means electrically connecting said other portions of said connector means to said wiring terminals within said housing.

10. The combination according to claim 9, wherein said conductor means comprises rectifier means for rectifying supply alternating current to provide energizing direct current for said coil, said rectifier having its input terminals connected to said wiring terminals and its output terminals connected to said second cooperating portions of said connector means.

11. The combination according to claim 10, wherein said rectifier means is a full-wave rectifier bridge and further comprises a zener diode connected between an output terminal of said rectifier bridge and the associated other portion of said connector means to be in series with said coil and oppose the coil current when electrically connected thereto.

13. In a convertible electromagnetic switching device, the combination comprising: an insulating enclosing case having a cavity with openings to opposite ends thereof, a central web extending across a first open end of said case to divide the opening therein into a pair of openings, and a pair of inwardly extending wall portions at the second open end of said case to reduce the opening therein; a first magnetic pole piece inserted within said cavity from said second end to abut said central web and having portions extending toward said second end; a coil member inserted within said cavity from said second end to abut said first pole piece between said extending portions, a central opening in said coil member aligned with said opening in said second end of said case and extending through said coil to open to said first pole piece; and at least one foot portion extending outwardly of said coil member, said foot portion having plug-in electrical connector means secured to an exterior surface thereof and connected to the windings of said coil, said connector means being in alignment with a respective one of said pair of openings of said case and within said cavity thereof; a core comprising a plurality of loosely stacked magnetizable laminations inserted within said central opening of said coil through said opening in said second end of said case, said core abutting said first magnetic pole piece; a second magnetic pole piece inserted within said cavity from said second end to abut an opposite end of said core, said second magnetic pole piece having portions extending along opposite sides of said coil toward said extending portions of said first pole piece and in alignment therewith; a mounting plate for mounting said switch device to a panel secured to said second end of said enclosing case to close the opening therein; biasing means disposed within said opening in said second end, said biasing means being compressed between said mounting plate and said second magnetic pole piece to bias said magnetic pole pieces, core and coil tightly against said central web within said cavity; means removably inserted into said cavity through a respective one of said openings in said first end to cooperatively engage said connector means for electrically connecting said coil winding to an energizing supply source; and at least one magnetically operable switch module removably inserted into said cavity through either of said openings in said first end to be operated upon energization of said coil.

15. A convertible electromagnetic switching device comprising in combination; a hollow insulating enclosing case; an electromagnet mounted within said case, said electromagnet including a coil having an axial opening therethrough, a magnetizable core extending through said axial opening and a pair of magnetizable pole pieces overlapping the respective ends of said coil and said core and extending toward each other along opposite external sides of said coil; at least one opening in said case adapted to receive at least one magnetically operable sealed switch means therein, at least one of said switch means removably inserted into said opening in said case to extend alongside of said magnetizable pole pieces at the opposite external sides of said coil of said electromagnet within said case to be operated upon energization of said electromagnet, and an indicator member mounted within said case alongside said electromagnet for removing toward and away from said electromagnet, said indicator member hAving a portion extending beyond said electromagnet and into a window opening formed in said case, means for biasing said indicator member to a first position within said window, and wherein said indicator is attracted to said electromagnet upon energization thereof to cause said portion within said window to move to a second position therein against the bias of said biasing means.