US2233925A - Magnetically operated device - Google Patents

Description

A. G. STIMSCN IAGNETICALLY OPERATED DEVICE Filed Dec. l, 1938 March 4, 1941.

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Inventor". Allen G. Sti son, 12j )Q/ Hi tborng.

'Ptentedlz Mar. 4, 1 941 UNITED sum-"riss:

PATENT OFFICE 2,233,925 mons'ncsur ori-maren DEVICE .uien G. simsen. smmwudy, N. Y., mmm to' Generalllectric Company, a corporation of New York applicati@ December 1, 193s, serial No. 243.376 s claims. (ci. 17a-33e) at the point o! required magnetic force. The

eil'ectotthisshadingcoilistodisplacethemagnetic ilux threading it relative to the ilux not .threading it, though. pursuing a parallel path. 5 "lhis displaced or shaded nur lags the unshaded nur by an electrical angle of less than 90 electrical degrees. Since the directions oi these two components of ilux are parallel. each provides its own component of magnetic force across the 0 pole face varying sinusoidally though slightly distorted by saturation oi.' the iron pole face. Each ci.' these force components is of zero value twich each cycle, but so long as the shaded component lags the unshaded component. the sum 5 oi these two forces is never zero. One feature of my invention relates to the provision of an improved pole shader construction using a pair of short-circuited windings, the iirst oi which enciicles a portion of the magnetic core and the o second of which encircl a second portion of the magnetic core as well as encircling the nrst portion oi' the magnetic core and leaving a third portion of the core unshaded. In this manner a threephase ux is provided at the pole face ot s the core member which gives a more uniform pull on the armature and therefore, more quiet operation and greater total pull.

Another feature oi my invention relates to a -reslllently mounted movable 1contact carriage g operable between an upper and lower xed oontact by the armature of the relay and adapted to provide a wiping engagement of the movable contacts with either of the nxed contacts.

For a more complete understanding of all the 3 features of my invention, reference should be had to the accompanying drawing in which Fig. l is a plan View of a magnetically operated relay embodying my invention; Fig. 2 is a left side elevational view of Fig. l; Fig. 3 is a sectional 3 view taken along the line 3-3 of Fig. l looking in the direction of thearrows; Fig. 4 is an inverted sectional view taken along the line 4-4 of Fig. 1 looking in the direction oi the arrows; Fig. 5 is an inverted sectional view taken along s the line 5 5 oi Fig. l looking in the direction of the arrows; Fig. 8 isan exploded view ot some o! the parts o1 the relay shown in perspective.

Referring to the drawing, I have shown my invention in onejorm as applied to a magnetical- -ly operated relay.- The relay includes a base :s

0i.' suitable insulating material upon which the various parts are mounted and secured. The bottom face of the base lll, best shown as the upper edge o! the inverted sectional view of the relay in Fig. 4, is provided with a groove I2 ex- 10 tending longitudinally thereof into which one'. leg o1 an L-shaped magnetizable frame I3 is =secured by means ot the hollow rivets or eyelets ll and Il cooperating with the base. The hollow rivets il and l5 themselves constitute 15 suitable bolt holes in the base I0 into which bolts may be inserted for fastening the relay to 1a panel or the like. 'I'he other leg of the L -shaped magnetlzable frame il extends upwardly' along one side ot the base IU; as seen in Fig. '3 pr0 20 jectin'g a short distance above the upper portion ol the base. A portion of the base Il is moulded with an opening across which extends the frame I3 as shown in Fig. 5 whereby a well or recess is formed into which a core member I8 25 and its energizing winding are disposed. The core memberv i8 consists essentially oi a series of laminations of magnetizable material fastened together by means of the rivets Ita to form an elongated pole piece or core member of substan- 80 tially rectangular cross-section. The vertically disposed core member l0, which extendsv upwardly from the bottom of the base ||l in the well provided therefor, is surrounded by a number oi. turns of tine wire constituting an ener- 35 gizlng coil H provided at its sides with the terminals I8, the core member I8 forming a support for the winding il and separated therefrom by a sleeve of insulating material i9 which surrounds the core member. v 4,()

As shown in Fig. 6, the core I8 has its lower end positioned in a recess 2l struck into an auxiliary frame plate 2| which is fastened to the core member I6 by a screw 22 threaded longitudinally into the bottom o! the core member. A 45 pair of extensions or ears 23 are provided on the auxiliary frame plate 2| having the holes 24 therein adapted to receive the screws 25 which are threaded into the frame I3 to secure the auxiliary frame plate 2| thereto. As shown, I 50 have provided a sheet oi insulating material 2G, such as paper, between the auxiliary frame plate 2| and the main frame I3 to increase the reluctance ot the magnetic circuit including these two members. On the auxiliary frame plate 2| 55 opposite the extensions further extension or nib a recess or slot in the Wall thereof for holding in position on the base.

With the auxiliary frame ing means I have 23, I have provided a 21 which registers with base I3 and engages a the auxiliary plate 2| plate 2I and fastenprovided, the core member I 6. the energizing winding I1, andl the auxiliary frame plate 2| may be easily assembled and disassembled from the base I and main frame I3 as a unitary structure when the relay is mounted on a panel. Thus, one is enaabled to make replacements in the held, particularly of the energizing winding I1, without disturbing the relay on its mounting. To disassemble the unitary core and winding, it is only necessary to loosen the screws 25 from the frame I3 and give the core I3 a slight twist or rotary motion to displace the nib 21 on the auxiliary frame plate 3l from its recess in the base I0 and then remove the core unit from its well in the base.

The screws 25, besides being easily accessible from the upper part ot the base I0 for uniastening by means of a screw driver, are also disposed in the holes 24 in the auxiliary trame plate 2| in a manner so that they will not fall out while these parts are being assembled or disassembled. At their lower ends the screws 25 are provided with a threaded portion 28 and at their upper ends nearest the head of the screw with an under cut portion 23 of reduced diameter. By providing internal threads in the holes 24, the lower threaded portions 23 of the screws 25 must be ilrst threaded through the holes 24. After that,

the under cut portions 23 of the screws 25 are loosely disposed in the holes 2Q`so that the screws 25 may be threaded into screw holes in the trame I3 to fasten the auxiliary frame plate 2I to the frame. Because of the internal threads in the holes 24, the screws 25 are not easily removable from the plate 2I without iirst aligning the threads i'or screw engagement and, therefore, are not likely to fall out of the auxiliary frame plate during assembly or coil replacement.

As hereinbefore explained, to provide a more uniform pull and increased quiet torque characteristics in the alternating-current magnet. I have provided a pole shading construction comprising a pair of parallel slots 30 and 3I in the upper end oi' the core member I6 which divide the cross-sectional area of the upper end ,of the core member into three distinct areas, which taken together comprise a single pole face 32 on the core. One of the three extending portions of the core member I6 comprising the pole face 32 is encircled by a shunted pole shader winding 33 which m 7 be formed of two short-circuited turns of copper wire or punched copper plates to provide a low resistance shader. The middle extension on the core member is encircled by a larger shunted pole shader winding 34 which also surrounds the shaded extension encircled by the pole shader 33 and may comprise a single shortcircuited turn of copper wire of substantially greater resistance value than the winding 33. The third extension on the core member I8 having no pole shader thereabout constitutes the unshaded portion of the pole face 32. The pole shaders 33 and 34 are secured in the grooves 30 and 3i respectively by swaging the these grooves. As shown in Fig. 3, it will be noted that the upper surfaces oi' the pole shaders 33 and 34 are on substantially the same plane, the slot 3I being only made deep enough for this `wardly extending leg purpose, and no deeper. to avoid undue weakening of the core member I3 at this point.

The cooperating individual shader windings 33 and '34, when properly proportioned, are well adapted to change the flux characteristics oi.' the core member I to provide a more uniform pull and greater quiet torque thanican be obtained with a single shader winding. The three phase iiux components provided thereby. when acting together, have a greater minimum intensity than the usual two phase flux. The intensity of this minimum value of iiux' isa determinant of .quiet Viiux value during each cycle, the less is the likeliing 331s, in eiect, doubly shaded.- A three phase component at the face lwhich i'ollows energization current in The middle portion of the pole tace 32 has a iiux component which lags the energization current by an electrical angle oi' less vthan 90, and the ux at the doubly shaded por`- tion lags the energization current to a greater extent than the middle portion, but less than 90 electrical degrees. Relative lag is determined b relative amount of shading provided by the shading windings 33 and 34.

Referring now to Fig. 3, the top o! the upof the frame I3 is provided with a iulcrum edge 33 on which an armature .side oi' the fulcrum edge 35 on the frame I3 is a projection 31 cooperating with a short projecting portion 38 of the armature 35 which extends across the fulcrum edge 35 and rests thereon. The projecting portion 33 of the armature 35 is disposed between the projections 31 on the frame which prevent any substantial lateral displacement of the armature 35 on the Iulcrum edge 33. The upper ends of the extensions 31 on the trame I3 extend laterally'inwardly over the projecting portion 33 of the armature 35 in an overhnging relation thereto for preventing any substantial upward movement oi.' the armature 35 oli .of the fulcrum 36. The projecting portion 38 of the armature 35 isnotched at either side to form the shoulders 39 which cooperate with the extensions 31 on the frame I3 to prevent any sub stantial longitudinal movement oi' the armature 35 on the tulcrum 36 in one direction. Secured to the upper surface of the armature 35 is a spring strip 4I) extending longitudinally thereof having a bent end portion 4I adjacent the tulcrum edge 36 which cooperates with the frame I3 to prevent any substantial longitudinal movement of the armature 35 on the iulcrum 3 6 in the other direction. In other words, the armature 35 is positioned on the fulcrum edge 38 and is prevented from moving more than a very limited amount longitudinally and laterally thereon by reason of the cooperating spring 40, the extensions 31 on the trame. and the shoulders 33 on the armature. By raising the end 6I, the

each cycleV is lessened. By en.

I spring 40 is deilected upward and removal of the armature 25 from the frame is permitted.

The main body of the amature 35 extends laterally above the oore member I5 and is pivotally movable about the fulcrum 45 adjacent the pole face 32 upon energization of the coil I 'L The opposite end -of the spring strip 40 from that nearest the fulcrum 25 extends beyond the end of the armature 45 and is resiliently supported by spring means which normally bias the armature to its unattracted position as well as provide a connection with contact operating means operable by the movement of the armature between its attracted and unattracted positions. Ihe support and contact operating means includes a guide member or post 42 which may be formed by a metal strip staked at its lower end into the frame I3. The upper end of the guide post 42 contains a slot or groove 42 running longitudinally thereof into which one prong of a. trifurcated end portion 40a of the spring strip 40 is disposed for movement up and down in .the groove 43. On the metal guide post 42, I have slidably mounted a contact carriage 44 of insulating material, the carriage 44 having a central aperture for receiving the guide post 42. The contact carriage 44 is molded with suitable wellshaped upper and lower ends to receive and seat a pair of helical springs 45 and 45 therein. The springs 45 and 45 encircle the guide post 42, the spring 45 serving to support the carriage 44 and resting on the insulating liner 25 of the trame i3'. The spring 45 is interposed between the upper side of the carriage 44 and the end 40a of the spring 40 to provide a resilient connection tor transmitting the downward movement ot the armature 35 to the carriage.

For adjusting the disposition of the armature 25 with respect to the free position of the spring 45, I have provided the spacing washers 4'| be tween spring strip 40 and the upper end of the helical spring 45. The spacing washers 41 are provided with an aperture 45 for receiving the guide post 42 and `have a pair of diametrically opposed inwardly extending portions 49 projecting into the groove 43 on the guide post 42. TheA ends of the projections 49 are spaced apart slightly less than the thickness of the end oi' the guide post 42 which forms the top wall of the groove 43. These washers may be made of any resilient material, preferably in the form of thin metal punchings which may be pushed over the end of the guide post 42 in the number desired and which will be retained in place thereon by the projections 49 disposing themselves in the groove 43. Because of the projections 4S, the spacing washers are unable to fail oil.' of the guide post 42 but may be easily assembled on and removed from the post, the projections 49 being forced apart slightly for this purpose in the course of assembly or removal.

Secured to the base i are the terminals 50a, ta, 52a, and 53a each connected to one of the fixed contacts 50, 5i, 52, and 58. The fixed contacts 50, 5| and 52, 52 comprise spaced apart pairs of contacts which cooperate with the movable contacts 54 and 55 respectively disposed therebetween for engagement with the upper set 5U and 52, as seen in Fig. 4, when the armature 35 is in the attracted position, and for engagement with the lower set of contacts 5I and 5I when the armature is in the unattracted position. Extending at opposite sides of the contact carriage 44 are a pair of arms 55 and 5l on which the movable contacts are mounted, the arms being displaced `oiI the center line of guide post 42 or offset for providing a leverage means on said contact carriage 44 whereby the carriage is given a tilting or pivotal movement as the contacts are engaged and disengaged. lThe contact carriage 44 is slidable on the guide post 42, as hereinbefore mentioned, and it is also arranged for limited pivotal movement about the guide post 42 so that the movable contacts 54 and 55 are given a wiping or rolling action upon engagement and disengagement with the respective fixed contacts.

The effectiveness and uniformity of this wiping action is enhanced by providing the pairs of pivot points 58 and 59 on the contact carriage 44 upon which the springs 45 and 45, respectively, are seated. The center lines of the pivot points are on the same vertical plane and are disposed adjacent the narrow edges of the guide post 42. The fixed contacts are also disposed on a common vertical plane which is parallel to the plane of the pivot points. In this manner, as the carriage 44 is slidably moved up and down along the guide post 42, a definite moment arm is provided for tilting the carriage 44 as the contacts engage and disengage. This definite moment arm for the tilting oi' the contact carriage 44 provides a substantially uniform wiping and rolling engagement of the contacts desirable for avoiding and breaking pin point welds on the contact surfaces, scrubbing dust and foreign matter therefrom and providing good engagement of the contacts.

Connecting the movable contacts 54 and 55 in circuit with a pair of' terminals 80 provided therefor secured to the base i0 arethe resilient conductors 5| which are adapted to tlex in accordance with the movement of the contact carriage. 4The conductors 5| are of substantially U-shaped configuration having outwardly bent ends at the point of connection with the terminals 50 'and movable contacts 54 and 55. To minimize the life shortening eflects of fatigue to which the conductors 8i are subjected during frequent operation of the relay over long periods by reducing the deiiection and hence the stress at the points of support, I have provided the strengthening members 52 and 53 at these outwardly bent end 'portions of the conductors 5i. The strengtheners 52 and 53 comprise strips of metal or other flexible material fitted along the inner curvature of the bends of the conductors 5i which assist in distributing the bending stress at these points over a wide area and greatly assist in prolonging the life oi' the conductors 5 l.

In operation of the relay, the armature 25 is normally supported freely by the springs 45 and 46 in the unattracted position above the pole face 32 of the core member I5. The movable contacts 54 and 55 are maintained in engagement with the upper fixed contacts 5i and 53 for making the circuit including the terminals 5Ia, the contacts 5| and 54, a. conductor 5| and a terminal 50, and the circuit including the terminal 53a, the contacts 53 and 55, a conductor 5|, and a terminal 50. When the winding i1 is energized, the armature .35 is attracted down'- wardly to the core i5 and the force of its movement is transmitted to the contact carriage 44 by the helical spring 46. The downward movement of the contact carriage 44 dlsengages the previously engaged contacts 5i and 54 also 53 and 55. Upon suillcient downward travel, the

l5 and 46 are bearing. This rocking action wipes.

the movable contacts il and Il across the fixed contacts Il. and I2 in a.Y desirable manner and ygood engagement of these contacts is provided.

Two further circuits' are then completed and each includes one o! the lower fixed contacts Il and 52 instead of the upper nxed contacts SI and 53 as before. The wiping engagement of the contacts 5i and 54 also il and Il occurs in an identical manner when the armature Il moves back toits unattracted position. Moreoven in 4each instance as the contacts disengage, some wiping action is effected between those contacts.

The switch device described herein is covered in my divisional application, Serial No. 331,662, med April 25, i940. Y

While I have shown a particular embodiment o1 my invention, it will be imderstood. o! course. that I do not wish `to be limite'dthereto since many modiiicationsv may be made. and I therefore contemplate by the appended claims to cover any such modiilcations as fallwithin 'the true spirit and scope of my invention. l

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

1. A magnetically operable device comprisin'ga 'nase of insulating material adapted to be mounted on a-panel, a magne'tic frame mounted on the bottom oi said base, a core member, an energizing winding on said core member,an auxiliary frame plate secured to the bottom of said core member having an extension thereon projecting beyond the periphery of said energizing winding; fastening means including said extension of said auxiliary frame plate accessible from the upper securel .side of said base for securing said auxiliary frame plate to said frame thereby enabling easy removal of said auxiliary trame plate.' core member. and energizing winding from said frame and base when said device is mounted on a panel.

2. A magnetically operable device comprising a base of insulating material adapted to be mounted on a panel, a magnetic frame mounted on the bottom of said base, a core member and an energizing winding therefor projecting upwardly in a well provided in said base, an aux' iliary frame plate secured to the bottom of said c-:are'member having a depression struck therein in which the end of said core member is seated and fastened, fastening means for securing said core member in said well on said base comprising a projection on said auxiliary frame plate which cooperates with a recess insaid base and may be positioned in an engaging relationship with a wall oi said recess and a further projection on said frame plate having an aperture for receiving a screw which threads into said magnetic frame,vsaid screw being accessible from the upper side oi said basefor enabling assembly and removal of said core member, energizing winding assenso and auxiliary frame plate when said device is mounted von a panel.l

3. A magnetically operable deviceoomprising a base o! insulating-material arranged to be mounted on a support with a bottom side next to the support and with an opposltely disposed top side. said base being provided with an opening, a magnetic `frame on the bottom side of said base and having a portion extending across said opening, said frame -belng provided with a leg extending -laterally from said bottom side across one end of said base. a magnetic core member forming a second leg. an energizing winding on said core member, a magnetic plate secured to one end of said core member having extensions pro- Jecting beyond the periphery of said winding. said plate and said winding iltting in said opening in said base', means cooperating with said extensions for detachably securing said plate to said frame with said plate in magnetic tiux conducting rdation with said portion of saidfi'ame.A

'4. A magnetically operable device comprising a base of insulating material provided with opmately disposed bottom and top sides, said bcc'- I tom s'ide' being proviciedviritlia` groove and .said base being Provided with -an'jopening communicatlnswithuid smovepa, A: ing a nrst leg nttingin'saidigroove and secured to said base; and encourt-leg extending across one end of said top side, a magnetis'able core member, a magnetizable plate secured to one end of said. core member, an energixing windingA mounted on said core member, extensions on said plate projecting beyond the peripheryfoi said windt!!!` laid plate and'said winding iitting into said opening in said base into magnetic nur conducting relation with said nrst leg, means cooperating with said extensions and accessible from said top side of said base for de tachably securing said plate to said nrst leg, whereby said core men'ibenplate and winding are secured to said nrst leg and removable as a unit from said front aide oi' said base.

5. A magnetically operable device comprising a base of insulating material provided with oppositely disposed bottom and top sides, said bottom side being provided with a groove and said base being provided with an opening between said sides communicating with said groove, an L- shaped magnetizable trame having a iirst leg iitting' in said groove and secured to said base, the second leg o! said frame extending across one end of lsaid base to a point above said top side. amagnetizable core member. a magnetizable plate secured to one end loi said core member, an energizing winding mounted on said core member -against said plate, extensions on said plate proand winding are secured to said iirst leg and removable as a unit from said front side of said base, and an armature pivotally mounted on the end of said second ieg movable to an attracted position into engagement with the other end oi said core member.

ALLEN G. STIMSON.

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