US2780756A - Electromagnetic actuator - Google Patents

Description

Feb. 5, 1957 o. TAYLOR ELECTROMAGNETIC ACTUATOR 4 Sheets-Sheet 1 Filed March 6, 1953 Fig.|.

WITNESSES: i /i/w g- ATTORN EY Feb. 5, 1957 o. 1.. TAYLOR 0,

ELECTROMAGNETIC ACTUATOR Filed March 6, 1953 4 Sheets-Sheet 2 Fig.2.

9Q. I I9 23 WITNESSES: INVENOR 4 7 E OwenL.Toylor. W MF W ATTORNEY Feb. 5, 1957 Q TAYLOR 2,780,756

ELECTROMAGNETIC ACTUATOR Filed March 6, 1953 4 Sheets-Sheet 3 g 3 Fig.4. f l I sissxssm I "I2 mm H i \m llllllllllllllllllllll m mm "ml 2% M I i H mammal IW ii WWII! "ml WITNESSES: INVENTOR Z437 OwenL To ylor. z gl BY M Mr. W

ATTORNEY Feb. 5, 1957 o. L. TAYLOR 2,780,756

* ELECTROMAGNETIC ACTUATOR Filed March 6, 1953 4 Sheets-Sheet 4 WITNESSES: INVENTOR 4w Owen L.Tuy|or. W4 BY M E, W

ATTORN EY controlli d v ce o e character I viates the defects, of the prior, art;

g 1 r. .magnet polelfaces for any cbnclitionlof the fc'i trc linade i .j c'i nit cqn i q l n de f l o si il st qi sn" 'al .-.:a'te (l type which isqu'iet in operation, never) .s'affy force-travel: relationship; is easy" :to as United States Patent ELECTROMAGNETIC ACTUATOR OwenL. Taylor, Easton, Count, assignor to -Westinghouse Electric Corporation, :East Pittsburgh, Pa, :1 corporation of Pennsylvania Application March 6 1955 Serial1No. 340,859

7 Claims. (Cl. s ngs herein should be such that the switch will be quiet and develop the necessary force-travel relationship. "The assembly should allow easy access to aiid removal .offthe operating coil and a minimum numberjof parts torremove and handle. The moving parts should be of sucha design as to insure long operating life. Y

The quietness of operation and the operating li fe of A. C. magnets are contingent upon alignmentfol the seating pole faces of the armature and vrna'gn'et, and l PQn the proper loading of the armature, aswenasipraper shading. The above factors are dependentvupon fthe proper mounting of the armature. If the magnet, and the armature pole faces are properly ground so ,that a large proportion of these faces are in practical contact when the armature is free, the only probler'nnof 'alignment is to have the armature mounted in sirens manner as to assume this position when mounie'dinnit's 'supporting member and when seated. Arnovenient about any axis parallel to the pole faces of the armamrtends "to make the device noisy at much lower-force vanes than when a load is applied to the 'armature'alongian axis perpendicular to the plane ofithe' pole faces and through thetheoretical center area of all peieg'raqes in combination (this center does not necessarilyfall within any of the actualseating areas). A loadapplit'edirr- ,a manner is referredto as a balanced load} Prior art methods of mounting 'afmatures have jtwto major drawbacks. First, the free floating armaturrallows .movement of thearmature about fits'..bearing'v pjar'tslwjth resultant wear in the armature mountingassemblyf'fiem nd, th'ereis no control over the movement 'or"tne,.armatureuntil thearmature isseated. Due lto'rriagn'eti involved one pole face will always make 'contact the other and the resultant relative moveme t of contact of the pole faces induceswear on t .area. i H It is an object of this invention to provide acireuit t fwhi l b' and oxides the requisite features.

Another object, or this invention is toproVide a-cireuit controlling device of'the 'ele ctromagn'eticallyoperatef p ype having the load applied to the arrriaturealon-g arigaxis -perpendicular to the .plan'e of the ,pole jface' Qand'subr fstantially. through, the theoretic'alfcenter are-a fiall pole faces. a. A. fur her obje t f thi enti n s. tent-W e that the armature ,p 'ole v faces rn'ayb aligned" magnet poler fa'ces to 1 give a balanced the armaturepoleQfaces areheld in ent .. sfiu: 311M116! obj c of this. inv t qn risi Q h joY lfi a ,3. have 2,780,75h i atented Feb. 5, 1957 ice Other obadvantages will become more apparent from as tu d'y of the accompanying figures, in which: figure 1 shows a front view of the assembled electromagnetic contactor; Fig. 2 shows a side view of the assembled electromagnetic contactor; Figs. 3, 4 and 5 show f vt vb i Fi'g."6shows the parallelogram arrangement through which rn otion is transmitted from thea'rmatureto the cfontactactuating m'eans; and l gsf7 and 8 sh'ow det'ails of the parallelogram arrangel. t e i l w M.

"jWith specific reference to the form of the invention asillust'i-atedtin Figs. 1 and 2 a base plate Z'is provided tendedportions3 and 4. The extended'portions h'les therein'for receiving afbolt'to fix'the base plfate of th'e relay to a panelboard. A resilient member efasff or example, a iubber'gr'ommet, is 'providedon the back offthe'base plate so that the extended'portions 3 satin a'ndthe resilient member 5 which give a snug ithfa panelboard when the contactoris fixedthereto a permits 'positive mounting withohlytwo mounting fsc'rewsior bolts on surfaces which may not be'perfectly i'flat'. The resilient member 5 also absorhsthe shock from the closing action of the contact'or.

details of the armature andthe 80 Co tact's'upport means 6, which supports fixed contactlrner nbers, a bearing bracket'17, and an eleetr'emagnet l arache't. 8,ffare attached to the base plate? may suitiahlernanner". The 'electromagnetbra'c'ket 8 'is comprised oi; twometa'llic members which fit on'each side of the laminated el troinagnet core 1 and hold thela'rninations together. portion of each metallic member extends perpendicular to the plane of the laminations and away "nemthe core 1 so that the metallic members may be fiiied tojtheba'se plate and thus hold the core 1 inposi- 40tion'f A coil 9'is provided'on" the center leg of the fli -shapedelectromagnefi The bearing bracket 7 is one of four plates which form a parallelogram arrangement. "Thegheariii'g bracket 7 has bearing surfaces at each end hich are'engaged by bearing edges of upper rocker arm .10 an-dthefl'owerrocker armll, respectively. The opposite caring edge ofthe upper rocker arm lWengages e na uiraee of, the armature bracket 12 and the bearing ijedge'at the o'pposite'end of the lower rocker arinfl l engages the lower bearing surface of the-arma- 'tnre br'acket'll vThe armature bracket 12 has a bolt 13 jprojec'tingthrough two extensions on the armaturebracket Ito secure thearmature 14 of the contactorbetweenthe leigte'nsions'. .Exten'sions at the upperend of the armassf t urefibracket ll are fixed to a contactac-tuatingarm or a ttnt ag' nn 15 and thus the movable eontacts of the contaetas semblies 18 either bridge thefixed contacts suppo r te l hynhe contact support means 6 or open the cireuit be tween the fixed contacts. The contact assembly "is shown and described in more detail in a cope'nding application of the same inventor entitled ElectromagneticContactor, filed herewith and assignedto the sarne :assi gnee 'The .coil 9 i sj held in position on-the center le 'g of the E- shaped electromagnet by means of spring members 19 fixed to the electromagnet bracket 8 'on the sides of the electromagnet. The spring members 19 are fixed in such a manner that they may be rotated out of contact with the coil 9 to allow easy removal of the coil.

Figs. 3, 4, and show the detail of how the armature 14 is fixed to the armature bracket 12. The armature 14 is provided with spacer members 20 along its outer surfaces and the armature bracket 12 is provided with spacer members 21. The spacer members 20 are in the shape of segments of a sphere and the spacer members 21 are shaped as matching segmental spherical sockets for the members 20.

The bolt 13 passes through the extensions on armature bracket 12, the armature 14 and the spacer members 20 and 21. Thus, it is seen the armature can move about any axis intersecting the theoretical center of the sphere of which spacer members 20 are segments within the limits imposed by the clearance to the mounting bolt 13. In practice, the nut on bolt 13 is tightened just enough that there is considerable friction at the spherical joint. Thus the coil of the electromagnetic contactor is energized several times to bring the faces of the armature 14 into contact with the faces of the electromagnet and the pole faces align themselves and the load is applied at the center of the ball or sphere which in turn gives a balanced load condition. Since considerable friction is involved in the area of contact at the spherical contact surfaces, there will be no relative movement of the armature 14 and the armature bracket 12 after the pole faces have been aligned. As a consequence, the armature pole faces are held in alignment with the magnet pole faces regardless of whether the device is sealed, open, or in transition. After the original pole face alignment, the nut on the mounting bolt 13 is tightened, thus increasing the frictional force in the joint which insures there will be no movement in the armature mounting joint and consequently the resulting wear in the joint is eliminated and also wear of the pole faces due to misalignment.

The parallelogram arrangement may be seen more clearly in Figs. 6, 7, and 8 wherein the armature bracket 12 mounts on two identical rocker arms and 11. The bearing formed at the junction of the rocker arms 10 and 11 and the armature bracket 12 are of the knife-edge type. The opposite ends of the two rocker arms 10 and 11 are mounted on the bearing bracket 7 and the bearing formed by the junction of the rocker arms and 11 with the bearing bracket 7 is also of the knife-edge type. The bearing formed by the junction of the upper rocker arm 10 with the bearing bracket 7 and the bearings formed by the upper rocker arm 10 and the lower rocker arm 11 with the armature bracket 12 are spring loaded by small compression springs 22 which are identical. The two springs 23 at the bearing formed by the junction of the lower rocker arm 11 with the bearing bracket 7 perform the dual function of keeping the bearing spring loaded and also providing a torque couple at the bearing to provide a positive return force for the armature 14 when the electromagnetic coil 9 is deenergized. The two rocker arms are shown as identical to simplify the manufacture but it will be noted that they are not used in exactly the same manner and, therefore, are not necessarily identical.

It will be recognized that the objects of the invention have been achieved by providing an electromagnetic contactor whereby a single electromagnet is employed to control the opening or closing of a plurality of circuits by means of the operation of switches and contacts. In addition, the electromagnetic contactor provides that the load will be applied to the armature along an axis perpendicular to the plane of the pole faces and substantially through the theoretical center area of all pole faces resulting in a minimum of wear both on the pole faces and also in the armature mounting joint.

4 that the invention is not limited thereto or thereby but that the inventive scope clearly includes equivalents.

I claim as my invention:

1. A quadralateral mechanical linkage comprising, a first and a second plate, said first and second plates having lateral slots in each end, a third and a fourth plate, said third plate having end portions which extend into one pair of lateral slots on said first and said second plates, said fourth plate having end portions which extend into the remaining pair of lateral slots in said first and second plates, said plates forming a parallelogram arrangement, resilient biasing means at each corner of said parallelogram arrangement to cause the four plates to forcibly While in accordance with the Patent Statutes, one best I known embodiment of the invention has been illlustrated and described in detail, it is to be particularly understood.

engage each other, the line of action of the force of said biasing means for at least one corner of said parallelogram being displaced from the plane of the laterally slotted plate thereat giving a torque couple.

2. An electromagnetic device comprising, a base plate, a bearing bracket fixed to said base plate and having bean ing surfaces at opposite ends, two rocker arms, each rocker arm having the bearing edge at one end engaging bearing surfaces at the opposite ends of said bearing bracket, an armature bracket, said armature bracket having bearing surfaces at either end engaged by the remaining bearing edges of said rocker arms in such a manner that said armature bracket, said rocker arms, and said bearing bracket form a parallelogram with the planes of said rocker arms substantially parallel, the first of said rocker arms having first and second helical springs in coaxial alignment with each other and substantially aligned with the longitudinal center line of said first rocker arm, one helical spring at either end biasing the hearing edges :of said first rocker arm against the bearing surfaces of said armature bracket and said bearing bracket, said second rocker arm having extensions in a plane perpendicular to the plane of the rocker arm and displaced from the plane of the bearing bracket, 21 third helical spring having its axis substantially in the plane of the second rocker arm and in substantial coincidence with the longitudinal center line thereof, said third helical spring biasing the bearing edges at the end of said second rocker arm engaged by said third helical spring against the bearing surface of said armature bracket; fourth and fifth helical springs having their axes in a plane substantially parallel to but removed from the plane of said second rocker arm, each of said fourth and fifth helical springs engaging one of said extensions and the bearing bracket to bias the bearing edges of the second rocker arm against the bearing surfaces of the bearing bracket and give a torque couple at the bearing. a magnetic core member fixed to said base plate within the area defined by said parallelogram, coil means on said magnetic core member for producing a magnetic flux in said magnetic core member, and an armature member within the area defined by said parallelogram secured to said armature bracket and positioned to be linked and moved by the flux of said magnetic core member toward said magnetic core member in a direction at substantially right angles to the planes of said rocker arms, to correspondingly move said armature bracket.

3. An electromagnetic device comprising, a base plate, a first and a second plate, said first and second plates having lateral slots in each end, a third and a fourth plate, said third plate having end portions which extend into one pair of lateral slots on said first and said second plates, said fourth plate having end portions which extend into the remaining pair of lateral slots in said first and second plates, said plates forming a parallelogram arrangement with said third and fourth plates in substantially parallel planes, resilient biasing means at each corner of said parallelogram arrangement to cause the four plates to forcibly engage each other, the line of action of the force of said biasing means for at least one corner of said parallelogram being displaced from the plane of the laterally slotted plate thereat giving a torque couple, said fourth plate being fixed to said base plate, a magnetic core mem her mounted on said fourth plate positioned within the area defined by said parallelogram, a coil mounted on said core member for producing magnetic flux therein when energized, and an armature member positioned within the area defined by said parallelogram mounted on said third plate and attracted by the flux of said core member toward said core member along a path at substantially right angles to the plancsof said first and second plates to thus move said third plate.

4. A quadrilateral mechanical linkage comprising a bearing bracket, two rocker arms in substantially parallel planes, each rocker arm having a bearing edge at one end engaging bearing surfaces at the opposite ends of said bearing bracket, an armature bracket, said armature bracket having bearing surfaces at either end engaged by said rocker arms in such a manner that said armature bracket, said rocker arms, and said bearing bracket form a parallelogram for any position of said armature bracket with respect to said bearing bracket, the first of said rocker arms having helical springs in coaxial alignment with each other, one at either end and substantially on the longitudinal center line of said first rocker arm, biasing the bearing edges of said first rocker arm against the associated bearing surfaces on said armature bracket and said bearing bracket, said second rocker arm having extensions in a plane substantially perpendicular to the plane of the second rocker arm and displaced from the plane of the bearing bracket, a third helical spring having its axis in substantially the plane of the second rocker arm and in substantial coincidence with the longitudinal center line of the second rocker arm, said third helical spring biasing the bearing edges at the end of said second rocker arm engaged by said third helical spring against the bearing surface of said armature bracket; fourth and fifth helical springs having their axes in a plane substantially parallel to but displaced from the plane of said second rocker arm, each of said fourth and fifth helical springs engaging one of said extensions and the bearing bracket to bias the bearing edges of the second rocker arm against the bearing surfaces of the bearing bracket and give a torque couple at the stated bearing point.

5. An electromagnetic device comprising, a base plate, a bearing bracket fixed to said base plate, two rocker arms in substantially parallel planes, each rocker arm having a bearing edge at each end, respective rocker arm bearing edges on corresponding rocker arm ends engaging respective bearing surfaces at the opposite ends of said bearing bracket, an armature bracket, said armature bracket having respective bearing surfaces at either end engaged by respective bearing edges on the remaining ends of said rocker arms in such a manner that said armature bracket, said rocker arms, and said bearing bracket form a parallelogram for any position of said armature bracket with respect to said bearing bracket, the first of said rocker arms having first and second helical springs in coaxial alignment with each other, one at either end of said first rocker arm and substantially on the longitudinal center line of said first rocker arm, said helical springs respectively biasing the bearing edges of said first rocker arm against the associated bearing surfaces of said armature bracket and said bearing bracket, the second rocker arm having a pair of laterally displaced extensions in a plane perpendicular to the plane of the second rocker arm and displaced from the plane of the bearing bracket, a third helical spring having its axis substantially in the plane of the second rocker arm and in substantial coincidence with the longitudinal center line of the second rocker arm, said third helical spring biasing the bearing edges at the end of said second rocker arm engaged by said third helical spring against the associated bearing surface of said armature bracket; fourth and fifth helical springs having their axes in a plane substantially parallel to but displaced from the plane of said second rocker arm, each of said fourth and fifth helical springs engaging one of said extensions and the bearing bracket to bias the bearing edges of the second rocker arm against the bearing surfaces of the bearing bracket and give a torque couple at the bearing, an E-shaped magnetic core member within the area defined by said parallelogram fixed to said base plate and having pole faces, coil'means mounted on said core member to produce magnetic flux in said core member when energized, and an armature member Within the area defined by said parallelogram mounted on said armature bracket and having faces to match the pole faces of said E-shaped magnetic core member and positioned to be linked by the flux of said E-shaped magnetic core memher and thus be magnetically attracted toward said core along a path substantially at right angles to said rocker arms.

6. An electromagnetic device comprising, a support; first, second, third and fourth plates arranged to form a parallelogram; each of said plates having each of its ends bearing against a different plate; resilient biasing means at each corner of said parallelogram arrangement to cause the four plates to forcibly engage each other and said biasing means for at least one corner of said parallelogram giving a torque couple; said first plate being fixed to said support, an E-shaped magnetic core member within the area defined by said parallelogram mounted on said first plate and having pole faces; armature means within the area defined by said parallelogram having pole faces to match the pole faces of said E-shaped magnetic core member; means mounting said armature means on said second plate with the pole faces thereof normally spaced from the pole faces of said E-shaped core member along a path substantially at right angles to the plane of one of the remaining plates, said second plate being opposite said first plate; said third and fourth plates at all times lying in substantially parallel planes; said armature means being linked by the flux of said core member and attracted toward said core member upon energization of said coil.

7. An electromagnetic device comprising, a fixed core having a coil thereon and a movable armature, said fixed core and said movable armature being formed of a plurality of punchings and having matching pole faces, said armature having a late-rally disposed hole therethrough extending through opposite armature side faces; a pair of members, one mounted on each of said side faces and each having a convex spherical surface an axis of which is aligned with the axis of said hole, the center of curvature of each spherical face being substantially at the longitudinal center of said hole, a movable support for said movable armature mounting said armature with the pole faces thereof normally spaced from and confronting the pole faces of said core to be linked and moved by the flux of said core toward said core when said coil is energized, said movable support having a pair of legs straddling the lateral dimension of said armature, each leg having a spherica socket receiving the corresponding one of said spherical faces in frictional contact relation, said legs and said member having holes therethrough substantially aligned with the hole through said armature when said pole faces are engaged, a tension rod of smaller cross-sectional dimension than said holes clearing through said holes and clamping the mating surfaces of said spherical faces and sockets in frictional engagement to maintain the position between the armature and said support established by engagement of said pole faces.

References Cited in the file of this patent UNITED STATES PATENTS

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