IE45854B1 - Miniature relay - Google Patents

Description

This invention relates to a relay structure and more particularly to an improved miniature relay of simplified construction.

Minature electromagnetic relays are in constant 5 demand as a result of the advanced degree of miniaturisation which has developed in the electronics arts. There is need to provide a miniature relay of low cost having a structure which allows simplified assembly. At the same time, it would be highly desirable to provide a minature relay having improved operating efficiencies, reliable operation and long life.

According to the present invention there is provided a motor assemly for a minature relay comprising an electromagnet assembly including a coil having an axial opening therethrough and a magnetic frame operatively associated with said coil and including a pole piece section extending along and outwardly of said coil and terminating adjacent one end of said coil and a core section extending along and through said coil opening and terminating in an end face adjacent the same end of said coil; a pair of spaced-apart holding elements extending from said electromagnet; an armature comprising a generally planar magnetic body having a pair of slots extending inwardly from opposite edges of said body and defining a recessed area therebetween, said pair of spaced-apart holding elements extending from said electromagnet defining a saddle for said armature recessed area; and biasing means for continuously urging said armature recessed area into said saddle defined by said holding elements in a manner such that said armature is spaced from said pole piece when said coil is deenergised. \ 45854 The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

Fig. 1 is an elevational view of a miniature relay according to the present invention with tha casing shown in section; Fig. 2 is an elevational view, with the casing removed, 10 taken along lines 2-2 in Fig. 1; Fig. 3 is a horizontal sectional view taken along lines 3^3 in Fig. 2; Fig. 4 is a horizontal sectional view taken along lines 4-4 in Fig. 2; 15 Fig. 5 is a horizontal sectional view taken along lines 5-5 in Fig. 2; Fig. 6 is a horizontal sectional view taken along lines 6-6 in Fig. 2; Fig. 7 is plan view taken along lines 7-7 in Fig. 2; 2o Fig. β is a vertical sectional view of the relay shown in Fig. 1; -445854 rig. 9 i« » fragmentary vertical «actional view similar to rig. 8 and showing tha armature in a de-energized position; rig. 10 ia a sectional view taken along lines 10-10 in rig. 9; rig. 11 ia * fragmentary sectional view of an alternative configurating of the cooperating armature and pole piece portions; rig. 12 ia a fragmentary sectional view of another form of tha armature and pole piece portions; rig. 13 ia an exploded, perspective view with parts removed of a miniature relay according to another embodiment of the present invention; rig. 14 ia a vertical sectional view showing the relay of rig. 13; rig. 15 is a fragmentary sectional view taken along lines 15-15 in rig. 14; rig. 16 la a sectional view taken along linaa 16-16 in rig. 15; rig. 17 ia a sectional view similar to rig. 15 showing 20 an alternative form of armature holding elements; and rig. 18 la · sectional view similar to rig. 16 showing an alternative form of armature holding element. -545854 Xn basic miniatur· relay structures a coil is carried by a frama of κagnatic material which includes a pole piece portion. Tbe elactramagnat assembly including coil and frame is mounted on a support header which includes current-carrying terminal pins extending therethrough, at least one pair of fixed contact members each coupled to a corresponding one of the terminal pins and located on one aide of the header facing tha coil and frame assembly and a movable contact member carried by the header, electrically coupled to another one of the terminal pins, movable between tha fixed contact members and normally engaging one of the fixed contacts.

An armature is movably mounted in tha structure and located between the header and coil and frame assembly with a portion of the armature spaced from the frame pole piece portion to define an air gap. Xn response to energisation of the coll, the armature is moved to close the air gap and complete a magnetic circuit including tha coil core, the armature and tha magnetic frama. Movement of the armature ia applied to the movable contact member placing it in angage20 mant with the other fixed contact.

Xn accordance with thia invention, tha magnetic frame includes a core portion extending longitudinally through and bsyond tha coil and terminating in an end facing the header. Tha frame also includes a pole piece portion operatively -645854 aaeociated with th· coil and which can terminate in a pole fao· disposed toward tha headerar an and portion diaposed at about a right angle to th· body of th· pol· piece portion. Tha magnetic fra·· ie fixed to * bridge-like supporting smm5 bar of non-magnetic material which, in turn, ia fixed to th· header, and th· frame cor· portion extend· through and beyond an opening provided in th· supporting member. Th· armature ie held in position by cooperation between a pair of paced-apart holding elements extending from the electromagnet io assembly and a portion of the armature shaped and dimensioned to fit in tha open region between the bolding elements. The holding elements can comprise spaced-apart extensions on tha and of tha magnetic frame core portion or, alternatively, spaced-apart poet· having ball-ehaped end· and depending from an insulative bobbin containing tha coil. The region between the holding elements provides a saddle for the armature portion, and the armature ie continuously purged into that saddle by biasing means in the form of a leaf-spring carried by the header. The pull-in force of the electromagnet can be enhanced 2o by a mating tab and notch configuration in the cooperating portions of the armature and pole piece or by having the angularly disposed end portion of the pole piece present increased surface to the armature. 74S8S4 Referring to the drawing·, the miniature relay 10 com prises several principal assemblies or elements including a motor assembly WhjLeh comprises * coil mounted between a magnetic frame and a non-magnetic support, an armature aseembly, and a header assembly which contains switch contact elements and terminal pins cn a supporting base.

Xn the relay structure shown, the header 12 ia formed of matal having a platform surface 13 of generally circular configuration with the header serving ss a supporting base for io the components, λ peripheral flange 14 cooperates with the lower flange portion of a casing or cover 16 which is suitably attached to the header aa by soldering or welding after aseembly of the components thereby hermetically sealing the relay structure. The peripheral surface of header 12 ia provided with diametrically-opposed flats 18, 20 whidt are mutually parallel and disposed perpendicular to the header surface 13.

The flat surfaces 18, 20 define right-angle Should·» which facilitate mounting of other component· of the relay structure on haadar 12. A guide tab 22 extends laterally from tha peripheral flange portion 14 and serves as a reference indi—β— cator fox plug mounting or wiring of tho relay in a known manner, A plurality of currant carrying terminal pin· 24 project through aperture· provided in header 12 and are secured by fused glass (not shown) which also provides both electrical insulation and a fluid-tight seal between header and each pin 24.

The contact assembly includes a first movable contact member or switch blade 28 carried by header 12 and electrically coupled to one of the terminal pins 24. As shown in i rigs. 2 and 3 a terminal pin 24 has an extended portion 30 which is bent or formed at about a right angle to the pin axis and extends inwardly in spaced parallel relation to the surface of header 12. Switch blade 28, which is in the form of a thin metal strip, is welded at one end to terminal portion and extends at about a right angle to portion 30 as viewed in rig. 3. The opposite or free end portion of switch blade 28 terminates slightly within the periphery of header surface 13 and is movable between a pair of fixed or stationary contact members 32 and 34 each electrically coupled to a 2o corresponding one of the terminal pins 24. Xn particular, contact members 32, 34 are in the form of short, relatively straight wire segments, for example silver wire, each having a diameter substantially equal to that of each terminal pin -S458 5 4 24« and each contact member 32, 34 is joined as by welding to a corresponding terminal pin about midway along the wire segment and is disposed substantially perpendicular to the corresponding terminal pin. As shown in Figs. 1, 3 and 4 the terminal pin to tdiich contact member 34 is welded extends a relatively greater distance from header surface 13 with the result that contact members 32, 34 are in spaaed relation to accommodate movement of switch blade 28 therebetween. Xn the relay structure shown, the fixed contacts ue generally mutually parallel, generally parallel to header surface 13 and are located within one quadrant of the circle described by the periphery of surface 13.

The assembly of movable contact 28 and fixed contacts 32, 34 ia located within one-half of the header surface 13.

The relay structure shown includes a similar assembly on the other half of the header surface 13 including axeacond movable contact member or switch blade 38 welded at one end to an inwardly extending portion 40 of a terminal pin and which haa a free and movable between another pair of fixed or stationary 2q contact members 42 and 44. The latter are in the form of relatively straight wire segments, for example silver wire, welded to corresponding terminal pine 24 and located in spaced, generally mutual parallel relation similar to the stationary -4043854 contaats 32, 34. Th· arrangement of switch blade 38 and fixed contacts 42, 44 on one half of header surface 13 is a mirror-image of the arrangement of switch blade 28 and fixed contacts 32, 34 on tha other half of the surface. In the relay structure shown, the lower stationery contacts 32 and 42 are generally coplanar and spaced-apart, and the upper stationery contacts 34 and 44 also are coplanar and apaced-apart. The movable contact members 28 and 38 are coplanar and, when the relay ie de-energized the movable contacts 28 and 38 engage the upper stationary contact members 34 and 44, respectively ae shown in Figs. 9 and 10. The metal strips 28, 38 have resiliency which preloads the strips against the stationary contact members. By way of example, switch blades 28, 38aan be strips of beryllium-copper alloy to provide resiliency coated with silver on the upper and lower surfaces. When the relay ie energized, the armature ie operated to move the switch blades 28 and 38 simultaneously into engagement with the lower stationary contact members 32 and 34, respectively, as shown in Figs. 1 and 2. 2o A biasing means in the form of a leaf spring member 48 ie supported by header 12 and operatively engages the relay armature. Spring member 48 ie in the form of an elongated atrip of spring metal formed to include an end tab portion which is -1145854 fixed as by welding to header surface 13, an intermediate portion which ie inclined with respect to header 12 and an enlargement 50 at the opposite and Which has a rounded surface adapted to engage the relay armature. Spring 48 is disposed generally diametrically with respect to header 12 and is positioned between the movable switch blade members 28 and 38 with enlargement 50 located adjacentthe fixed contact members. Spring 48 preferably is coated with Teflon or other high surface lubricity material to reduce friction between the spring member and relay armature to increase operating efficiency.

A metal stop element 52 is fixed as by welding to header surface 13 adjacent the end tab of spring 48 and includes an elevated and curved portion 54 defining a rounded surface for contacting the armature to support it in the denergized position The curved portion 54 can be bent toward and away from header surface 13 by using a miniature screwdriver and pliers to adjust the stop and thereby change the rest or denergized position of the relay armature.

The motor assembly includes a wire coil 56 wound on a bobbin ef insulative material which includes epaced-apart end flanges 58« 60 joined by a core section 62 as shown in further detail in rig. 8. In the relay structure shown, ends 58« 60 -1245854 ar· of generally rectangular configuration and core 62 defines a rectangular opening extending along the longitudinal axis of the coil as shown also in rig. 6. The coil is positioned in the relay structure with the longitudinal axis of the coil substantially , perpendicular to tha header surface 13. λ pair of conductive ribbons or strips 64, 66 ara molded in the and flange 60 nearest header 12 and are in spaced-apart generally parallel relation, λ coil lead 68 ia waldad or soldered to the end portion of ribbon 64 extending from flange 60 near tha coll,as shown in rig. 1, and a return lead 69 ia soldered or waldad to tha and portion of strip 66 as shown in rig. 8. The opposite end portions of ribbons 64, 66 extending from flange 60 are bent or formed to extend generally perpendicular to flange 60 and extend through openings provided in 15 tha relay armature and are welded to terminal pins 24. Thus, current is delivered through ribbon 64 and lead 68 to excite the winding 56 and operate the relay. λ magnetic frame 70 includes an and portion 72, a pole portion 74 operatively associated with coil 56 defining a 2o magnetic pole face 76 and a coxa portion 78 extending axially through tha coll opening and beyond tha coll, frame 70 ia ferromagnetic material and formed with pole portion 74 being of -1345854 arcuate cross-section and extendingin ‘generally orthogonal relation to and portion 72. Pole portion 74 is of considerable arauata length, extending along substantially one side of the coil 56, and also is of a dimension measured parallel to the axis of coil 56 such that end portion 72 is adjacent one axial end of eoil 56 and pole face 76 is located axially beyond the opposite end of coil 56. Core portion 78 is of rectangular aross-section and also extends in generally orthogonal relation to end portion 72 and terminates in an end surface located beyond the coil. Frame 70 is formed by metal stamping and forming techniques facilitated by notches 80, 82 adjacent the bend between core portion 78 and end portion 72 shown in Fig. 7. The width of core portion 78 is less than the corresponding dimension of frame end portion 72, and an 15 open area is defined in tha and portion by a pair of spacedapart, generally parallel edges 84, 86 shown in Fig. 7 which extend inwardly to notches 80, 82. Frame 70 also includes a pair of spaced, parallel lags 88 and 90 extending at fight angles to and portion 72 in tha same direction as pole 74 and core 78 and terminating in tab portions 89 and 91, respectively, shown in Figs. 1 and 8. Legs 88 and 90 are located in a somewhat straddling relation to cora 78. Furthermore, tha mutually -1445854 parallel plena* In which lags 88, 90 are disposed are substantially perpendicular to tha plana of core portion 78.

A support element 98 of non-magnetic material euch aa brass or aluminum supports coil 56 and magnetic frame 70 on header 12 in spaced relation to surface 13. Support element includaa a base portion 100 Which ia generally rectangular in shape having an opening 101 located generally centrally thereof and further includes a pair of lag portions 102 and 104 extending from opposite ends of base portion 100 at right lo angles thereto and in the same direction. Support ela&ant 98 is formed to include a pair of openings 106 and 108 adjacent the junctures between legs 102, 104 and base portion 100 and extending along tha legs as shown in rigs. 1 and 8. Support element 98 ia formed by metal stamping and bending operations μ which are facilitated by the notches 110 adjacent the bends as shown in rig. 5.

During assembly of tbe relay, legs 102 and 104 of support 98 are waldad to flats 18 and 20, respectively, of header 12 as shown in rigs. 1 and 2. Lege 88 and 90 of frama 70 are welded to support 98 with tabs 89 and 91 being received in openings 106 and 108, respectively, of support 100 to facilitate asseably and alignment aa wall as provide added structural rigidity. Coil 56 is supported With end flange 60 contacting base portion 100 of the support. Tha frama core portion 78 Ί6— extends through opening 101 in base 100 in relatively close fitting relation which holds core 78 firmly in position against lateral movement. The foregoing arrangement provides a simple vertical alignment of the relay components which affords simplified assembly.

An armature 116 is located in spaced relation to header and is in the form of a planar, plate-like body of ferromagnetic material having a first portion or end tab 118 provided with an operator element 120 of insulative material for 1Q operatively engaging the movable contacts or switch blades 28, 38 as shown in Figs. 8 and 9. The elongated element 120 is of sufficient length to bridge both movable contacte 28, 38 .and is fixed in a suitable manner to the lower eurface of armature tab 118. The opposite end of armature 116 has a curved or arcuate edge 122 of , substantially the same curvature as pole piece 76. In the relay structure shown, the edge 122 is provided with an inwardly extending notch or recess including spaced-apart side edges 124, 125 joined by an inner, arcuate edge 126, and this notch reaeivas a tab 128 extending 2o from pole piece 74, in particular depending from pole face 76, the tab and notch being in relatively closely-fitting reler tion. Whan the relay is de-energized, the portion of armature 116 adjacent edge 122 is spaced a small distance from pole face -1676 to define an air gap, end the air gap includes the gap or space along the mating tab and notch configuration.

The armature 116 has opposite side edges 130 end 132 which are substantially parallel and which join the opposite ends of the armature as shown in Fig. 4. λ first inwardly extending recess or slot ie defined by a pair of edges 134, 136 extending in from edge 130 which meet an inner end aurface 138. Edges 134, 136 diverge slightly outwardly from surface 138. λ second inwardly extending receee or slot ia aligned ΐθ with the firet slot and ie defined by a pair of edges 140, 142 extending inwardly from edge 132 which meet an inner and surface 144. Edges 140, 142 diverge slightly outwardly from surface 144. She inner end surfaces 138 and 144 are substantially parallel and define therebetween a recessed area or 15 portion of the armature.

Core 78 of magnetic frame 70 terminates in an end surface having an elongated recessed region defined therein between a pair of spaced-apart, depending extensions or ears 148 and 150 aa shown in Figa. 4 and 10. The recessed or open region extends in a direction generally perpendicular to tha longitudinal axis of coil 56.

The distance between the armature notch inner end surfaces 138 and 144 allows the region of armature 116 therebetween to be received in tha recessed region between the -1745854 extending ears 148 and 150 of cor· 78 in a manner such that the two ears 148, 150 provide a saddle-like region for the armature portion. The armature ia continously urged into that saddle by the aation of leaf spring 48 the rounded enlargement 50 thereof contacting the lower surface of armature 116 adjacent end tab 118. The foregoing arrangement permits limited angular movement of armature 116 about or relative to the region between ears 148, 150 along a plane parallel to the longitudinal axis of coil 56. Xn the relay structure shown, io armature 116 moves along a plane perpendicular to the length of the region defined between extensions 148, 150. The region between extensions 148, 150 is generally rectangular in shape and includes a planar inner surface 152 disposed substantially perpendicular to the longitudinal axis of core 78. The inner surface of extensions 148, 150 are disposed substantially perpendicular to surface 152. The length of the region between extension 148, 150 is several times greater than the width, the width in turn is equal to the thickness of core 78 at the end surface thereof, and angular movement of armature 116 2o is in a plane substantially perpendicular to the length of the region between extensions 148, 150.

Armature 116 is provided with apertures 156, 158 shown in fig. 5 laterally spaced and adjacent edge portion 122 through Which the conductive ribbons 64 and 66, respectively.

-IS45854 extending from coil flange 60 axe fed or directed to corresponding terminals 24 to which the ribbons ere welded.

The relay structure is assembled in the following manner. After assembly of header 12 is completed, including terminal pins 24, movable contacts 28, 38, fixed contacts 32, 34 and 42, 44, leaf spring 48 and stop 52, the motor assembly including coil 56 and frame 70 is fixed to supporting element 98 by assembly and welding as previously described. Then this combination is fixed to header 12 by welding legs 102, 104 10 to header 12 as described. Then armature 116 is assembled in position with the area or portion between edges 138, 144 placed in the saddle-like region between core extensions 148, 150 and held therein by leaf spring 48. As shown in Fig. 9, when coil 56 is not energised, the lower surface of armature 116 15 adjacent edge 122 engages the curved portion 54 of the stop, the armature upper surface between edges 138, 144 engages the edge of core surface 152 facing the end 118 of the armature, and the armature ie held or maintained in this inclined position with respect to header surface 13 by spring 48 which 2o engages the lower surface of armature 116 adjacent end tab 118.

Fig. 11 shows an alternative arrangement of the mating notch and tab configuration between armature and pole wherein pole 74 of a magnetia frame 70a is provided with a notch or recess extending inwardly from pole face 76 and including -1945854 spaced-apart substantially parallel side edges 124a, 125a which meet an inner edge 126a disposed substantially parallel to pole face 76. An armature 116a·-; is provided with a tab 128a extending from the arcuate end thereof into the pole recess.

Fig. 12 shows a portion of the armature end pole of a relay v 5 structure having an armature 116b which terminates in a smooth continuous arcuate end surface which cooperates with a smooth, cintonuous pole face 76 of a frama70b.

In the de-energized condition of the relay, the movable contact® 28 and 38 axe preloaded against the normally closed stationary contacts 34 and 44, respectively, and the armature 116 is biased against the stop 52 by the return spring 48. Therefore, the electrical path in this position is from the normally closed stationary contacts 34 and 44 through the movable contacts 28 and 38, respectively, each circuit being independent of one another. In this condition, the circuits including normally open contacts 32, 42 are electrically inoperative.

With the application of electrical power through the appropriate terminal pins 24 end coil leads to coil 56, the coil is energized causing armature 116 to be magnetically attracted to frame 70. This magnetic force overcomes the biasing force of leaf spring 48 and the preloading of movable contacts 28, 38 and causes armature 116 through operator element -IS45854 120 to move the switch blades 28 and 38 froa the normally closed contacts 34 and 44, respectively, into engagement with the normally open contact» 32 and 42, respectively. Xn this position, an electrical signal can ba transmitted froa the normally open contacts 32 and 42 through the movable contacts and 38, respectively. Suring this operation armature 116 moves about the recessed region between core extensions 148, 150 with the edge of surface 152 previously described serving as a fulcrum in contact with the armature surface. After a email degree of angular movement the armature 116 comas to rest with the upper surface adjacent edge 122 contacting pole face 76. Xn the foregoing position, tt^e electrical circuits Including normally closed contacts 34, 44 are electrically inoperative. When the electrical potential to coil 56 ie 15 removed, armature 116 loses magnetic attraction to frame 70 and ie moved to the initial or rest position by action of leaf spring 48 and the resiliency of switch blades 28, 38.

Figs. 13 - 16 show a miniature relay according to another embodiment of this invention. The header and contact assembly ie identical to that of the embodiment of rigs. 1-10. Briefly, end referring to Fig. 14, a metal header generally designated 164 has a platform surface 165, and the header carries a plurality of currant carrying terminal pins 166 which projeat -214 5 8 5 4 through apertures in header 164 end are secured by fused glass (net shown). A movable contact member or switch blesto 168 in feaa form □£ a thin strip of resilient metal is carried by header 164 and electrically coupled such as by being «aided at one end to one of the terminal pins in a hgesos similar to the arrangement of rigs. 1-10. The opposite or free end portion of switch blade 168 is movable between a pair of spaced-apart, fixed or stationary ©onfeeet aambafa 170 and 172 in the form of matal wire segments lo each electrically coupled to a corresponding one of the terminal pins 166 such as by welding. As in the embodiment of Figs, 1-10, feh® foregoing assembly of movable contact 168 and fixed contacts 170, 172 \Ls located within one-half of tho h-aedar surface 16S, and a similar assembly -of movable .15 contact and fixed ccnfcacta is located within the other half ®f the header earfae*. A biasing means in the form of a matal leaf spring member 174 is supported by header 164 and operatively engages the relay armature, λη adjustable metal atop element 176 is fixed to header surface 165 and establishes tha rest or deenergised position of the relay armature. Spring member 174 and etop element 176 are identical in structure, location and ogarafeien to spring member 48 and atop element 52, respectively, of ths embodiment of riga. 1-10. -2243854 The motor assembly includes a wire coil 180 wound on a bobbin of insulative material which includes spaced-apart end flanges 182, 184 joined by a core section 186 as shown in further detail in Fig. 13. Xn the relay structure shown, ends 182,184 are of generally rectangular configuration, core 186 define· a rectangular opening extending along the longitudinal axis of the coil, and the coil is positioned in the relay structure with the longitudinal axis thereof substantially perpendicular to header surface 165. λ pair of conductive ribbons or strips 188, 190 are molded in the and flange 184 nearest header 164 and are in spaced-apart generally parallel relation. A coil lead 192 ls welded or soldered to the end of ribbon 190 as shown in Fig. 14 and a return lead (not shown) is similarly connected to ribbon 168. The opposite end portions of ribbons 188, 190 extend through openings provided in the relay armature and are welded to terminal pins 166 as in the embodiment of Figs. 1-10. Thus, current is delivered through ribbon 190 and lead 192 to excite the relay. 2o A magnetic frame 196 includes a generally planar end portion 198, a pole piece operatively associated with aoil 180 and comprising a main body portion 200 and an end portion 202 tftiich terminates in an arcuate end face 204, and a core -33^.3834 psrfeisjj 2QS extending axially through th· coil opening and tosyosd ths coil where it terminate· in a planar end face 203. Framo 1SS is ©f ferromagnetic material and formed t?ifeh the pole piece sain body portion 200 being generally plsaas aad extending in generally orthogonal relation to oad ps®tion 138. The pole piece main body portion 200 ie of eeMid®r®&X® width, extending along substantially one sida Jie coil 180« and also is of a length measured parallel tfeo the exits of coil 180 such that frame and 198 is adja1Q @gb& ©so axial end'of coil 180 and pole piece end portion 202 is located axially beyond the Opposite end of coil 180. Scec 206 is of rectangular cross-section and alao extends in goiaorally orthogonal relation to end portion 198 and taxmiasatas in end surface 208 located beyond the coil. End face is rectangular and disposed in a plane generally perpendicular to tine axis of eoil 180. Frame 196 is formed by satai standing and forming techniques similar to frame 70 ©f tao embodiment of Figs. 1-10. Frame 196 alao includes a pair of spaced, parallel legs 210 and 212 extending at right angles to end portion 198 and terminating in tab portions 214 and 216, respectively, legs 210 and 212 are located &s-.:q aseaabafe straddling relation to cora 206« and the mutually parallel please in «hich legs 210, 212 are disposed are substantially perpendicular to the plane of core portion 206. -244 3 8 5 4 λ support element 220 of non-magnetic material such as braes or aluminum supports coil 180 and magnetic frame 196 on header 164 in spaced relation to surface 165. The support element includes a generally rectangular base portion 222 and a pair of leg portions 224, 226 extending in the same direction from opposite ends of base 222 and at right anglea thereto. An elongated, rectangular opening 228 is provided in base 222 generally centrally thereof, a pair of openings 230, 232 are provided between the ends of the central opening 10 and corresponding ones of the legs 224, 226 which openings preferably are circular in shape, and a pair of generally rectangular openings 234 and 236 are provided at tha junctures between base 222 and legs 224 and 226, respectively, which openings extend along tha upper portions of the legs as shown in rig. 13.

An armature 240 is located in apaced relation to header 164 and is in the form of a generally planar, plate-like body of ferromagnetic material having a first portion or end tab 242 provided with an operator element 244 of insulative material fixed to the lower surface of tab 242 and of sufficient length for operatively engaging both the movable switch blade elements as in the embodiment of rigs. 1-10. Ths opposite end of armature 240 haa a amooth, continuous curved or arcuate edge 246, and surface 204 of pole piece end portion -255 8 S J 202 has substantially tha same curvature as edge 246. When th® relay Is deenergised, the portion of armature 240 adjacent C'Sgo 246 ia spaced a small distance from pole piece end portion 2Θ2 to define an sir gap.

Th® axmatura 240 has substantially parallel opposite sifia edges 240, 250 joining the opposite ends thereof, and ( fisst and second rectangular shaped recease· or slots 252 I and 254 extend inwardly from edges 248 and 250, respectively. The two slots are substantially perpendicular to tha correslo ponding side edges, are aligned, and the inner end surfaces or eSgea of the slots are substantially parallel and define therebetween an armature recessed area or portion of reduced laterali^imansica. The armature also has a pair of relatively Barrow elongated slots 256, 258 extending inwardly from edges 248, 250 at locations between corresponding ones, of the recesses 252, 254 and the arcuate edge 246. Slots 256, 2S8 or® generally perpendicular to the side edges, are aligned and extend inwardly a slightly greater distance than the corresponding recesses 252, 254. The provision of slots 256, 258 permit® the regions containing recesses 252, 254 to be formed slightly out of th® plane of the remainder of the armature for a purpose which will be described. In the relay structure ch©», th® plans of the armature upper surface is disposed about mid-way of th® thickness of the two raised portions. 264 5 8 5 4 λ pair of opening* 259, 260 are located near edge 246 for receiving the depending portion* of the coil ribbons 168, 190.

A pair of armature holding elements 264 and 266 extend in spaced-apart relation from the electromagnet assetobly, in particular from end flange 184 of the coil bobbin, and define an elongated open region therebetween. Bolding elements 264, 266 ere located adjacent and inwardly of opposite ends of tbs rectangular flange 184 and are located eo that the elongated open region therebetween le disposed perpendicular lo to the longitudinal axis of coil 180 and parallel to the elongated end surface 208 of core 206. Bolding elements 264, 266 are disposed in mutually parallel relation and are perpendicular to end flange 184. Bolding elements or posts 264, 266 ar* of non-magnetic material and preferably are molded or otherwise formed integrally with the coil bobbin.

In the relay structure shown each holding element has a generally frusto-conical body portion 264*, 266a with the larger diameter end adjacent flange 184 and each element terminates in a generally ball-shaped or substantially spherical formation 264b, 266b. As shown in Fig. 15, holding elements 264, 266 are of the same overall length, and the diameter of the spherical end portion is substantially equal to the diameter of tha base of tha conical portion. The poet* 264 and 266 extend through the openings 230 and 232, respectively, in supporting 27· 8 5 4 elaaeafc 220.

The distanee between the inner end surf aces of the armature notches 252 and 254 allow* the region of armature 240 to be received in the elongated open region between the holding elements 264 and 266 in a manner euch that the two poet elesasfcs 264o 266 provide a saddle-like region for the armature portion. The armature is continuously urged into that noddle by the action of leaf spring 174, the rounded enlargement thereof engaging the lower surface of armature 240 xo adjacent end tab 242. The foregoing arrangement provides limited angular movement of armature 240 about or relative to the region between posts 264, 266 along a plan* which is substantially parallel to the longitudinal axis of coil 180 end substantially perpendicular to the length of the region X5 between posts 264, 266 and to core end surface 208. The upper surface of armature 240 between the raised surface portions including slots 252, 254 contacts the edge of core end surface 203 facing armature end tab 242, and the armafcuna moves about this edge when it doses tha air gap as Shown Pig. 14o The ball-like ends 264b, 266b of the post elcaents have only point contact with surfaces of the armature slots 252, 254 thereby minimizing mechanical friction.

The ends 264b, 266b of the posts co-operate with the armature 246 in a manner analogous to a ball bearing mount. The post -2815 8 5 4 •leaanta 264, 266 are spaced from opposite ends of the core ^surface 208, and the centers of the spherical ends 264b, 266b of the post elements are located on a line which is coincident with the edge of core end surface 208 about which the armature moves. As armature 240 moves about this edge, the movement is along a plane disposed between posts 264, 266 and, in particular, along a plane parallel to the longitudinal axes of the posts. The armature portions containing slots 252, 254 are formed to be offset or raised slightly from the re10 mainder of the armature permitting the surfaces of the slots 252, 254 to encompass the post spherical ends 264b, 266b while the edge of core surface 200 contacts the armature surface and is aligned with the centers of the post ends 264b, 266b.

Having poets 264, 266 of non-magnetic material such as nylon and the like prevents any magnetic attraction between the armature and the posts which might otherwise influence the desired armature movement. Providing posts 264, 266 integral with bobbin flange 184 simplifies eisembly and lowers aost. The entire core end surface 208 is planar thereby in20 creasing tha amount of mating surface area between armature and core which, in turn, increases the amount of magnetic force generated by coil 180. This provides more available force for actuating the relay and increases the efficiency of the relay magnetic path. The central points between the post 29A 3 8 (i 4 scads 2S4b, 266b and armature 240 are relatively near the armature aide edges 2480 250. This outboard location of the »·. ( points of engagement together with proper manufacturing tolerances decreases radial slop or play in the armature thereby enhancing osaainboEioy aad reliability of relay operation.

Th® pole piosa end portion 202 provides a turned or folded wor frames pad of increases surface area which faces Hso oafi of armature 240 adjacent the arcuate end 246. Xn particular, end portion 202 ia disposed at about a right angle io to sain body portion 200 and extends outwardly away from coil 180. Tho disposition of end portion 202 presents a Qurfnea toward armature 240 Which is greater in area than tho cross-section of main body portion 200. This increases the cfficisicy of the magnetic assesibly and provides more force for actuating the relay.

Ir Ac alternative armature holding elements, Fig. 17 shows cylindrical post elements 270, 272 of non-magnetic materialSpending frea coil bobbin flange 184 at the same locations ae posts 262, 264. The cylindrical posts 270, 272 con bo of nylon or like non-magnetic material, and the posts have line contact with corresponding surfaces of the armature notches 252, 254 in a direction parallel to the longitudinal asses of post® 270, 272. -304-38 5 4 As a further alternative, tha armature holding elements can comprise a pair of posts extending from the supporting element 220. Th* post· ar* of non-magnetic material such aa braes or nylon and ar* located in spaced relation within 5 legs 224, 226 and depend from th* lower surface of base 222.

Ae shown in rig. 18, each poet has a cylindrical body portion 278 fixed in an opening in base 222, a generally frusto-conical intermediate portion 278 and a ball-like spherical end 280.

The poets can be of the same metal, i.e. brass or aluminum, lo aa supporting element 220 but preferably one of nylon and pressed into openings in base 222. Th* location of such openings can be identical to that of openings 230, 232 shown in rig, 13.

The relay structure is assembled in a manner similar to the embodiment of rigs. 1-10. After assembly of the various part* on header 164, the motor assembly including coil 180 aad frame 196 ie fixed to supporting element 220 with posts 264 and 266 extending through openings 230 and 232, respectively.

Than this sub-assembly le fixed to header 164 by welding legs 224, 226 thereto. Armature 240 ia assembled in position with the are* or portion between the inner edges of notches 252, 254 placed in the saddle-like region between poets 264, 266 and held therein by leaf spring 174. A can cr housing (not shown) is attached to header 165 after assembly of th* pert· -314 5 8 5 4 to seal tha relay structure as in the embodiment of rigs. 1-10 'She stashed, vertical arrangement of components provides ease to asaesafely eafl ttaa Xwera manufacturing cost. tassa soil 180 io not energized, the lower surface of 5 Gasaafeas® 240 adjacent edge 346 contacts the curved portion of Has otep i?S0 the armature yppar surface between recesses 252 0 254 contacts the eSgo of core surface 208 facing the end 242 ®£ t'ae ®aste23; and She armature is held or maintained in thia toeltoed psaifeiea aith respect to header surface 16S by lo cpstog 14 Which e&sfeaeks the lower eurface ef armature 240 aSjseeat ©ad tab 242. With feha application of electrical gstzas through th© «appropriate terminal pins 166 and coil laeda to eoil 1@0, the coil is energized causing armature 240 fe© ha QagaofeicalXy attracted to frame 196 and move to the (energised position shewn in Fig. 14. The conditions of the electrical circuits including the various relay contests in Sa de-energized snd energized positions of armature 240 is toonfeXasl to those· of th® relay shown in Figs. 1-10.

Psca th® 5©g®getog description of the structure and operation of tba Illustrated embodiments of this invention, it io apparent that an Improved miniature relay of simplified construction has fessa provided. The miniature relay of this tovcaki@n is of low cost employing a simple vertical alignment 324 5 8 5 4 or stacked relationship of the relay components for simplified assembly thereby to minimize assembly cost while at the same time providing improved relay operating efficiencies. The armature le not secured to the magnetic frame but rather ia held in position solely by the cooperation of the spacedapart holding elements depending from the electromagnet assembly which saddle a recess area in the armature, the armature being continuously urged therein by the armature return spring. The foregoing together with the magnetic frame being ot one piece including pole and core which also serves as a support frame for the coil simplifies the structure and assembly of the miniature relay. Xn addition, having tho armature moved about an edge of tha magnetic frame, i.e. about the edge of the core end surface, reduces series air gaps in the magnetic path thereby reducing losses in the electromagnetic circuit during initial energisation of the relay. Providing the holding elements in the form of posts of nonmagnetic material having substantially spherical ends reduces or substantially eliminates mechanical friction and magnetic attraction in an undesired direction which might otherwise impede normal armature movement. The mating tab and notch configuration of the cooperating portions of armature and pole increases the overall extent or length of the magnetic &· cPs gap along feha azsate and pole portions and along tha configuration, 5-hio gives rise to a so-called motor effect t&Qgesy ths ptsll-isa fores of the electromagnet Is enhanced ifeo ths ©oil is eaosgissd. Alternatively, having the pole picso eafi portion disposed af about a right angle to the pole picso nata Iee^i? portion presents increased pole piece area to ths oraaturo fo eohasrae th® pull-in force of the electroEsgaafc, erovidiag tts bridge-like support element of non' ncgaofio B&feorial prevents loss of magnetic flux through the io support and Halts ths flux path or circuit to include the ssiJ, fees:® and osEiafeur®. The provision of conductive ribbons solved ia feho inBslffitivQ end flange of the coil bobbin which qsq fed or directed through apertures in the armature siapli2iao f&o aekiag of eoil connection during asseably of the rales’.

Claims (23)

1. Motor assembly for a miniature relay comprising an electromagnet assembly including a coil having an axial opening therethrough and a magnetic frame operatively associated with said coil and including a pole piece section extending along and outwardly of said coil and terminating adjacent one end of said coil and a core section extending along and through said coil opening and terminating in an end face adjacent the same end of said coil; a pair of spaced-apart holding elements extending from sai cl electromagnet; an armature comprising a generally planar magnetic body having a pair of slots extending inwardly from opposite edges of said body and defining a recessed area therebetween, said pair of spaced-apart holding elements extending from said electromagnet defining a saddle for said armature recessed area; and biasing means for continuously urging said armature recessed area into said saddle defined by said holding elements in a manner such that said armature is spaced from said pole piece when said coil is deenergized.

2. Motor assembly recited in Claim 1 wherein said holding elements comprise spaced-apart extensions on said core end face.

3. Motor assembly recited in Claim 1 wherein said holding elements are of non-magnetic material.

4. Motor assembly recited in Claim 3 wherein each of said holding elements terminates in a substantially spherical end portion having point contact with surfaces i r of the corresponding one of said armature slots.

5. Motor assembly recited in Claim 4 wherein said armature contacts an edge of said core end face, S said holding elements are spaced from opposite ends of said core end face, and the centers of said spherical end portions are aligned with said edge of said core end face.

6. Motor assembly according to any one of the preceding claims, wherein its magnetic circuit comprises 10 a coil carried by a magnetic frame having a pole piece terminating in a pole face portion and an armature having a portion spaced a small distance from said pole face portion defining an air gap therebetween when said coil is de-energized, said armature adapted for movement in 15 response to energization of said coil to close said air gap, said pole face portion and said armature portion having a closely-fitting, mating tab and notch configuration which increases the extent of said air gap along said armature and pole face portions to enhance the pull-in 20 force between said armature and pole piece when said coil is energized.

7. Motor assembly according to any one of claims 1 to 5 wherein its magnetic circuit comprises a coil carried by a magnetic frame having a pole piece 25 including a main body portion and an end portion, and an armature having a portion spaced a small distance from said pole piece end portion defining an air gap therebetween when said coil is de-energized, said armature adapted for movement in response to energization of said coil to close said gap, said pole piece end portion being disposed at an angle to said main body portion in a manner such that the area of the pole piece end portion surface facing said armature is greater that the cross-sectional area of said pole piece main body portion thereby enhancing the pull-in force between said armature and pole piece when said coil is energized.

8. Motor assembly for a miniature relay according to claim 1 comprising an electromagnet, wherein this electromagnet comprises a coil within a magnetic frame including spacedapart leg members extending there’orni, a supporting base, and a supporting element of non-magnet.i.e material comprising a generally planar body portion and a pair of leg members extending thereform, said leg portions of said supporting element being fixed to said base, said leg members of said magnetic frame being fixed to said supporting element and said coil being supported on said planar base portion of said supporting element.

9. Motor assembly recited in claim 8 wherein a pair of spaced-apart armature holding elements extending from said body portion of said supporting element toward said supporting base, said armature holding elements being located between said leg portions of said supporting elements.

10. Motor assembly recited in claim 8 wherein said magnetic frame leg members are fixed to said supporting element at locations adjacent the junctures between said planar base portion and said supporting element legs. 5

11. Motor assembly recited in claim 10 wherein said supporting element is provided with an opening adjacent each juncture between said planar base portion and said leg members and said supporting element is provided with another opening in said planar base portion generally 10 centrally thereof, each of said leg members of said magnetic frame being provided with a tab extending from the end of said leg member which fits in a corresponding one of said supporting element openings, said opening in said base portion receiving a magnetic core extending from said 35 coil.

12. Minature relay including a motor assembly according to anyone of the preceding claims, wherein it comprises a support header having a plurality of terminal pins extending therethrough: 20 a pair of fixed contact members each electrically coupled to a corresponding one of said terminal pins and positioned on one side of said header; a movable contact member carried by said header and electrically coupled to another of said pins, 25 said contact member having a portion movable between said fixed contact members and normally engaging one of said members; motor assembly supported on said header in spaced relation to said one side of said header with holding elements facing said header; the armature of said motor assembly having a first portion operatively engaging said movable contact, a second portion operatively associated with said pole piece and a third portion shaped and dimensioned to be received in said open region between said holding elements in a manner permitting limited angular movement of said armature relative to said open region along a plane disposed between said holding elements; and biasing means supported by said header and engaging said armature in a manner urging said armature third portion into said open region- between said holding elements normally so that said armature first portion allows said movable contact to engage said one of said fixed contact members and said armature second portion is spaced from said pole piece; whereby in response to electrical energization of said coil said armature second portion is attracted to said pole piece thereby moving said armature against said biasing means causing said first portion to move said movable contact into engagement with the other of said fixed contact members.

13. Minature relay recited in claim 12, wherein said coil has an axially extending opening formed therein, wherein said magnetic frame has a portion extending 4 585^ along and through said coil opening defining said magnetic core of said coil, said core terminating in an end beyond said coil, and wherein said holding elements comprise spacedapart extensions on said end of said core.

14. Minature relay recited in claim 12, wherein said coil is wound on a bobbin of insulative material having a pair of end flanges, said bobbin being disposed so that one of said end flanges faces said header, and wherein said holding elements extend from said one end flange. 15. Miniature relay recited in claim 14 wherein said holding elements are formed integrally with said bobbin flange and wherein each of said holding elements terminates in a substantially spherical formation.

15. Miniature relay recited in claim 12 wherein said armature comprises a generally planar body having said first and second portions adjacent opposite ends thereof and joined by opposite side edges of said body and wherein said third portion is defined by a pair of aligned recesses extending inwardly from said opposite said edges and each recess terminating in an inner edge, said inner edges being spaced apart a distance less than the length of said Open region between said armature holding elements.

16. 17. Minature relay recited in claim 16 wherein said inner edges of said armature recesses are substantially parallel and are disposed substantially perpendicular to the length of said open region between said holding elements, the distance between said armature recess edges providing a relatively close fit of said armature third portion between said holding elements. 43854

17. 18. Miniature relay recited in claim 12 wherein said supporting means comprises an element of non-magnetic material fixedly secured to said header and having a portion on which said frame and coil are fixedly carried.

18. 19. Miniature relay recited in claim 12 wherein said coil is wound on a bobbin of insulative material having a pair of end flanges, and further including a pair of conductive leads each having an intermediate portion embedded in one of said bobbin end flanges, one end of each lead being electrically coupled to said coil and the other end of each lead being electrically coupled to a corresponding one of said terminal pins.

19. 20. Miniature relay recited in claim 19 wherein said leads extend from said bobbin end Flange through corresponding apertures in said armature to said terminal pins.

20. 21. Miniature relay recited in claim 12 and a stop element having a portion fixed to said header and a portion extending therefrom for engaging said armature to establish the rest position of said armature when said coil is deenergized, said extending portion being curved and adjustable in position toward and away from said header to adjust the rest position of said armature.

21. 22. A motor assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

22.

23. A miniature relay substantially as hereinbefore described with reference to and as shown in the accompanying drawings.