US2621269A - Electromagnetic relay with compensated contact pressure - Google Patents

Electromagnetic relay with compensated contact pressure Download PDF

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Publication number
US2621269A
US2621269A US68228A US6822848A US2621269A US 2621269 A US2621269 A US 2621269A US 68228 A US68228 A US 68228A US 6822848 A US6822848 A US 6822848A US 2621269 A US2621269 A US 2621269A
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Prior art keywords
blade
spring
relay
springs
contact
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Expired - Lifetime
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US68228A
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English (en)
Inventor
Yves J G Juillard
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International Standard Electric Corp
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International Standard Electric Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H50/00—Details of electromagnetic relays
    • H01H50/64—Driving arrangements between movable part of magnetic circuit and contact
    • H01H50/68—Driving arrangements between movable part of magnetic circuit and contact with snap action
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H50/00—Details of electromagnetic relays
    • H01H50/16—Magnetic circuit arrangements
    • H01H50/18—Movable parts of magnetic circuits, e.g. armature
    • H01H50/32—Latching movable parts mechanically
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/20—Control lever and linkage systems
    • Y10T74/20576—Elements
    • Y10T74/20582—Levers
    • Y10T74/20588—Levers toggle

Definitions

  • a blade operates a group of mobile springs the number of which depends on the use for which the relay is intended.
  • the said springs When the said springs come into contact with the stationary springs, they must exert a certain pressure on these springs in order that the corresponding electric circuits may be properly established. Because of this they undergo a certain amount of deformation and thus exert on the blade certain forces which, compounded with the electromagnetic forces, produce resultants which must be taken into account in the design of the various coil members. It is, therefore, necessary to design a special spring for a given spring set-up which will meet the various operating conditions required in each particular case, and this makes their manufacture more complicated and costly.
  • an adjusting screw is frequently employed which is screwed into the blade and which permits adjustment of the airgap when the said blade is attracted. It is thus possible to change at will certain characteristics of the relay, such as its attraction and release characteristics.
  • the use of gages in the adjustment of the various contact springs is also obviated.
  • the use of these screws has a certain number of drawbacks; they are generally associated with a braking device which substantially increases the cost of the relay; they must be very carefully ground so as to give the desired accuracy, and they wear rapidly.
  • the results obtained with them depend on the group of spring contacts. For example, a heavily loaded relay will always release rapidly irrespective of the size of the airgap adjusted by the screw.
  • This invention relates to a relay whose coil has electrical characteristics practically indedependent of the spring assembly and which does not require any device for adjusting the airgap when in the operating position.
  • One of the features of the invention is based on the fact that a compensating force or a force equal but opposite in direction to the mobile spring assembly is exerted on the blade in each of its positions, so that in the absence of any other force the mobile part of the relay is in a position of neutral equilibrium.
  • the blade In some relays the blade must be in the operated position when the coil circuit is closed, and in the unoperated position when the coil circuit is open.
  • Another feature of the invention is based, in
  • Another feature of the invention is based on a method whereby the compensating action is obtained by a force applied to an intermediate part which acts on the blade in such a manner that the intermediate part produces a compensating action only when the mobile contacts press either on the front contact or on the back contacts.
  • Another feature of the invention is based on a method whereby the point of application of the force acting on the blade moves in such a way that the component that produces the compensation is greater during the establishing of the front contacts than during the establishing of the back contacts, or vice versa.
  • the compensating action is a function of the number of spring contacts, a device for adjusting the value of the said compensating action must be provided.
  • Another feature of the invention is based on a blade-pressure spring one end of which presses against the intermediate part that acts on the blade, it being possible to adjust the tension of the said spring by any suitable means, and the other end of the spring being rigidly attached to an adjusting part which permits displacing the point of application'of the force exerted by the said spring.
  • Figure 1 is a compensated contact pressure rela
  • Figures 2 to 4 are diagrams showing the operation of the relay of Fig. 1.
  • Figure 5 is a variant of Figure 1 wherein it is possible to increase the spacing between the back contacts and the front contacts.
  • Figure 6 is a large scale view of the compensating device of Figure 5.
  • Figure 7 is a diagram showing the operation of Figure 5.
  • Figures 8 to 10 are diagrams showing the operation of a partially compensated contact pressure relay.
  • Figure 11 is a side view of one embodiment of a compensated contact pressure relay.
  • Figure 12 is a profile view of the relay of Fig. 11, showing the blade side.
  • Figure 13 is a top view of Figure 1.1, without cover.
  • Figure 14 is a profile view of the relay of Fig. 11, showing the contact side.
  • Figure 15 is a view of the relay of Figure 11, from which the cover and contact springs are assumed to have been removed.
  • Figure 16' is a plan view in half section along I-.I of Figure 11.
  • Figure 17 is a perspective of the attaching part of the lower part of the stationary contact springs.
  • Figures Band 19 are perspectives of the two attaching parts of the upper part of the stationary springs.
  • Figure 20 is a detail view showing the spring contact assen'iblyw and the associated insulating p s.
  • Figure 21 is a detail view showing the deformation of the mobile contact springs in the operated position.
  • Fi ure 22 is a side view of the attachin parts of Figures 18 and 19..
  • Figure 23 is a view of the plunger.
  • Figure 24 is a view of a mobile spring contact.
  • Figure 25 is a profile view in half section along III-III of Figure 2.2.
  • Figure 26 is a. View of a stationary contact spring and of the associated attaching part.
  • Figure 27 is a view of the attaching device of the mobilecontact springs- Figure 28 is a sectioned view along IIII of Figure 15, showing the shape of the springs which permits the h'inging of the blade to the yoke.
  • Figure 1 shows a relay comprisin a coil l, a yoke 2 and a pole piece 3.
  • Moving blade 4 has a knife-edge part 4 which is supported on yoke 2.
  • the mobile contact springs 6, only one. of which is shown in order not to complicate the figure, are inserted in a part I attached to the yoke, and operated by bladed by means of a plunger 8.
  • the springs 6 press against either back contacts 9 or front contacts l0, dep n ing on the position of the blade.
  • Aspring ll, operatin under compression is attached on the one hand to the upper end l6 of the blade and on the other hand to a point 5% on the ext nsion 12 of the-pole piece.
  • a restoring sprin 1.3 i attached on the one hand to the blade and on the other hand to a stationary part ltl.
  • a stopv ll limits the motion of the blade when the blade is not attracted.
  • themobile contact springs 6 When themobile contact springs 6 are in the meanposition 6', they do not exert anypressure on the blade of the relay; but when they come against back contact 9 or front contact l6 and eX- ert a certain pressure on the said contacts, they are deformed and thus apply a .force 1' to' the blade, this force being directed in a direction opposite that of component ,fl due to the compensatin spring. If the distance the mobile springs move is small, then it is permissible to assume that this force 1" is a'linear function of the displacement e of the blade.
  • Figure 4 is a diagram of the variousforces involved.
  • the displacements e of the end of the blade-from its mean position are plotted as .abscissas, and the mechanical stresses, as ordinates.
  • Let 0G and 0G be the two extreme values of e. Since the force r dueto the deformation of the mobile springs and the component fl due to the compensating spring always act in opposite directions, the former was considered positive and the latter negative in this. diagram.
  • twoscales were used for the said forces, these scales being proportional to the said lever arms.
  • the portion A0 of the curve shows the manner in which 1' varies during the establishing of the front contacts, and 0C the manner in which 1' varies durin the establishing of the back contacts.
  • A0 and 0C are symmetrical with respect to the axis of ordinates YY.
  • the portion D0 of the curve shows the manner in which the component fl of the compensating spring varies when the blade is between the attracted position and the mean'position; OE shows the manner in which the component fl varies when the blade is between the mean position and the release position.
  • the slopes of the portions OD and OE of the curves may be .made equal .and of opposite sign to those of 0A and 0C.
  • the component fl due to the compensating spring is then equal and opposite in sign to the reaction r of thepmobile springs on the blade. If restoring spring I 3 is eliminated, :the blade is then in a state of neutral equilibrium, irrespective of the con struction of the spring assembly. 7
  • the curve J of Figure 4 shows the manner in which the electromagnetic forces vary as a function of the distance traveled, and HI, the manner in which the tension of the restoring spring l3 varies.
  • the curve HI is substantially rectilinear. In order for the relay to operate properly it is necessary and sufficient that the electromagnetic forces be reater than the action produced by the restoring spring for each position of the blade, i. e., that the curve J be located completely above curve HI.
  • the attractive force to be provided is small, if the restoring spring [3 is suitably chosen, and it is not necessary to have a magnetic circuit with low reluctance when the relay is attracted.
  • a part l8 (side view) comprises a knife-shaped part l9 and a curved part 20 which can roll without slipping on a surface 2
  • Part I8 is held in place by a pressure spring 23 one end of which bears against the knife point l9, and the other end, on a part 21 supported in a groove 29 in yoke 2.
  • a nut 25, screwed on a threaded rod 26, permits adjustment of the spring tension.
  • a screw 28, screwed in pole piece 3 permits, through part 21, the displacing of spring 23 in order to change the position of the point of application 24 of the force F exerted by the spring. So that this motion may occur spring 23 is provided with an elongated opening 3l for the passage of rod 26.
  • the point of application of force F is adjusted in such a manner that part l8 and the blade are in the extension of each other when the said blade is in the mean position.
  • the position of part [8 is so adjusted that, when the blade is in its mean position, the midpoints of the two profiles 23 and 2
  • Point 33 of the blade, which is in contact with part I8, is subjected to a force directed toward the pivot of the said blade; this force does not have therefore any useful component permitting motion of the blade in either direction. Since there are no forces present due to electromagnetic effects or to the restorin spring, the mobile assembly of the relay is in a state of neutral equilibrium.
  • the instant mobile spring 6 presses against front contact ID, the end points 34 and 35 of profiles 2i and 20 are brought into coincidence. If the blade continues to move toward the left, profiles 20 and 2[ cease to be tangent; the blade carries along part It at point of contact 34, and the point of application 24 of force F approaches the pivot of the armature.
  • Spring 6, whose deformation is continuously increased, applies a force r to the blade, as shown in Figure 5, and this force increases with the displacement of the blade.
  • the force exerted on the point 34 of the blade is no longer directed toward the pivot of the blade; consequently, it has a component fl which tends to cause the blade to pivot toward the left. This component counteracts the force r produced by the deformation of mobile spring 6.
  • the device operates in exactly the same manner when the blade moves to the right from its mean position.
  • the curve ABB'C (Fig. 7) shows the manner in which the force 1' varies with the distance e of the end of the blade from its mean position, and DBBE, the manner in which the useful component ,fl of force F varies with this distance.
  • the point of contact of parts 4 and l8 is in line with the point of application of the force and the hinged joint of the blade, 1. e., as long as the distance e does not exceed one of the values GB or OB, the forces 1* and ii are zero, and both curves lie along the axis of abscissas.
  • a restoring spring l3 has been provided in order to keep the relay in its unoperated position when the coil circuit is not closed.
  • This retarded'action is, in-general, obtained by associating with the relay a ring, made of copper or another metal which is a good conductor, the purpose of which -is'--to retard the building up or collapse-of the flux in the relay. -If the'relay has a certain number of contact springs, however, the flux necessary for holding the relay in the attracted position is high, and even if it decreases only slowly, the
  • the system considered has a great advantage as regards adjustment. Because of the compensating device, it is easy to obtain with a small number of ampere-turns large displacement and high contact'spring pressures; the corresponding electric circuits will always be closed securely,
  • the coil of the relay comprises a'winding'3l (Fig. 15), wound on core 38, and two spool ends 39 and 55.
  • Pole piece Al is attached to core 38 by means of nut 'l w, screwed on threaded rod 55.
  • the said rod is itself screwed into orrigidly attached to the said core with. any suitablemeans.
  • the other end of the core is attached to yoke 42 through screw 33.
  • Blade M is hinged tothe end 55 of the yoke by means of a spring 4 6 which seats on the pole piece l, has a curved portion 51 (Fig. 28) ,which traverses theyoke andblade,
  • Part 65 is kept in place, on the pole piece, bystationary springs 6!, and-part'fikis held in place on threaded rod 55, already mentioned (Fig. 15) bymeans of a nut 63 and a washer (i9.
  • Ahole l'il is made in part 51 for passage of the threaded rod.
  • the other ends of the stationary springs are inserted in grooves ll (Figs. 16 and 17), made in two parts, such as 12.
  • the twin contacts of the stationary spring 6! agegzshown at 85, 8: (Fi 26) and the terminal a Parts E5 of the mobile contact springs 83 (Fig. 24) are inserted'in grooves 86 (Fig. 16) of parts, such as 85; the said parts have projecting parts 86 and 8'! which are installed in openingsmade in the yoke and part 52, side byside with'the projectingportions of parts 72.
  • the said springs Since it'is quite di-fiicult to make sufliciently narrow grooves in parts 85 for "the insertion of the thin mobile springs, the said springs have a curvedfportion l9 (seen in profile, Fig. 27-) this curved portion being so dimensioned-that the springs are held in place'in the. grooves in such away that they cannot move.
  • the grooves in parts i2 and those'of that l'a mobile spring may be placed between two stationary springs.
  • the mobile springs occupy grooves 88' of two plungers 89 (Fig. 23).
  • the plungers 89 are supported by a thin rod 90 having the shape of a U, shown in Figures 12 and 13, which enters two holes 9I and 92 made in the blade 44, and in holes 93 of the said plungers.
  • Rod 90 ends in two threaded parts 94 and 95.
  • a flexible T-shaped part 96 ( Figures 13 and 14), reinforced by a rib I I, and attached to the yoke by means of screw 55, holds rigidly the U-shaped rod and prevents it from pivoting around its middle branch. This part is held by two nuts 91 and 98, screwed to the threaded parts of the U-shaped rod 90.
  • Two springs 99 and I00 installed between blade 44 and plungers 89, keep part 96 against nuts 9! and 98.
  • the flexible portion of part 96 has been provided in order to facilitate displacement of the mobile contact springs.
  • the twin contacts associated with the mobile springs are shown at I01, I08 (Fig. 24) and the terminal at I09.
  • Figure 12 shows the first stationary contact spring removed, in order to show the associated mobile spring.
  • Insulating parts I02 are applied to the faces of the stationary springs that do not have any contact.
  • the thickness of the said parts is the same as that of the contacts they replace.
  • These parts are inserted in grooves 63 and 64, of part 55, and in portions I03 of the grooves of part 61, on the one hand, and in grooves II of parts 12, on the other hand.
  • Insulating parts I02 enter, just as stationary springs 6
  • the contact spring assembly is so arranged that each stationary spring is associated with an insulating part, in the manner shown in Figure 20.
  • the width of a groove is then equal to the sum of the thicknesses of a spring and an insulating part.
  • the relay is attached to a part I04 (Fig. 11).
  • a cover I05 is placed on the said part, thus forming a dust-proof enclosure for the various electrical contacts.
  • the said cover is held in place by a nut I05 screwed on threaded rod 55.
  • a switch device comprising a support, an electromagnet mounted on said support, an armature pivotally mounted on said support and adapted to be moved in one direction about its pivot by the action or said electromagnet, means 10 for normally moving said armature about its pivot in the other direction, a compensating member pivotally associated with the other end of said armature and substantially in line therewith, means for pivotally mounting the other end of said member on said support, means for urging said compensating member towards said armature so as to produce a toggle action between said member and said armature, a pair of spaced contacts insulatedly mounted on said support, a spring strip insulatedly mounted on said support and having one end between said contacts so as to engage said contacts alternately as the spring strip is moved in first one direc tion and then the other, a plunger for connecting said spring strip with said armatur so as to cause it to move when said armature is moved, and means for adjusting the pressure of said member against the end of said armature so that the toggle efi'ect of said
  • a switch device comprising a support, a pair of spaced contacts individually mounted on said support, a conductive element insulatedly mounted on said support and having one end between said contacts so as to engage said contacts alternately as the conductive element is moved in nrst one direction and then the other.
  • a lever pivotally mounted on one end on said support, a plunger member connecting said conductive element with said lever so as to cause it to move when said lever is moved, compression means pivotally engaging said lever at the other end thereoi' and secured to said support, said compression means being normally in aligmnent with said lever and operable to urge said lever out of alignment therewith when said lever is moved so as to produce a toggle action between the lever and the compression means, means connected to said lever for normally moving said conductive element towards one of said contacts, and power means for moving said conductive element towards the other OI said contacts against the action of said last named means.
  • said means for normally moving said conductive element towards one of said members comprises a biasing spring connected at one end to said lever and at its other end to an extension of said support and wherein said power means for moving said element towards the other of said members comprises an electromagnet positioned on said support adjacent said lever for controlling said lever.
  • a switch device comprising a support, a toggle mechanism including a compressionlink and an armature pivotally mounted on said support, means connecting a conductive element to said armature so that it movable therewith, a pair of spaced members mounted on said support adjacent said conductive element on opposite sides thereof, whereby said spaced members act asfstops "for themovement of said conductive element, first means including said toggle mechanism for applying a motive force normally urging said conductive element towards one of said members, power driven means confi d to i mat r for applying a motive force for moving said element towards; the other of said members against the action of, said first.
  • means means including a, compensating mem-v ber for compensating the pressure of said con,- ductive element ag illfi said members, saidcompensating member being connected tothe. compression link so as to produce togglecaction-between saidcompression link and said armature,

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  • Electromagnetism (AREA)
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US68228A 1947-12-31 1948-12-30 Electromagnetic relay with compensated contact pressure Expired - Lifetime US2621269A (en)

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FR295256X 1947-12-31

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US (1) US2621269A (de)
BE (1) BE486545A (de)
CH (1) CH295256A (de)
FR (1) FR959293A (de)
NL (1) NL71922C (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2777923A (en) * 1952-08-08 1957-01-15 Ralph H Munson Relays
US2841032A (en) * 1952-11-14 1958-07-01 British Thomson Houston Co Ltd Operating mechanisms for electric circuit control devices
US3194917A (en) * 1963-03-04 1965-07-13 E & R Lab Service Corp Knee-action relay
US3530415A (en) * 1966-11-15 1970-09-22 Foerderung Forschung Gmbh Electrodynamic snap-acting actuator
US20130207755A1 (en) * 2012-02-13 2013-08-15 Stephan Lehmann Hinged armature bearing for magnetic tripping device

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US286917A (en) * 1883-10-16 fraser
US1380168A (en) * 1917-12-20 1921-05-31 Monitor Controller Co Thermostatic switch
FR537787A (fr) * 1921-02-17 1922-05-30 Relais à bascule
US1439231A (en) * 1920-09-15 1922-12-19 Arthur F Erickson Valve-operating device
GB309096A (en) * 1927-12-23 1929-03-25 Charles Holden Victor Pate Improvements relating to electromagnetic relays for use in telephone systems
US1869610A (en) * 1928-01-19 1932-08-02 Western Clock Co Electric switch
US1991113A (en) * 1932-03-30 1935-02-12 Eclipse Aviat Corp Electromagnetic switch
US2075499A (en) * 1936-01-11 1937-03-30 Bell Telephone Labor Inc Switching device
US2323961A (en) * 1941-12-31 1943-07-13 Bell Telephone Labor Inc Relay armature
US2348088A (en) * 1940-11-20 1944-05-02 Ibm Detachable relay
US2351038A (en) * 1941-02-05 1944-06-13 Gen Motors Corp Refrigerating apparatus
US2377596A (en) * 1943-01-02 1945-06-05 Automatic Elect Lab Battery charging system
US2418235A (en) * 1943-07-10 1947-04-01 Gen Motors Corp Electric motor control

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US286917A (en) * 1883-10-16 fraser
US1380168A (en) * 1917-12-20 1921-05-31 Monitor Controller Co Thermostatic switch
US1439231A (en) * 1920-09-15 1922-12-19 Arthur F Erickson Valve-operating device
FR537787A (fr) * 1921-02-17 1922-05-30 Relais à bascule
GB309096A (en) * 1927-12-23 1929-03-25 Charles Holden Victor Pate Improvements relating to electromagnetic relays for use in telephone systems
US1869610A (en) * 1928-01-19 1932-08-02 Western Clock Co Electric switch
US1991113A (en) * 1932-03-30 1935-02-12 Eclipse Aviat Corp Electromagnetic switch
US2075499A (en) * 1936-01-11 1937-03-30 Bell Telephone Labor Inc Switching device
US2348088A (en) * 1940-11-20 1944-05-02 Ibm Detachable relay
US2351038A (en) * 1941-02-05 1944-06-13 Gen Motors Corp Refrigerating apparatus
US2323961A (en) * 1941-12-31 1943-07-13 Bell Telephone Labor Inc Relay armature
US2377596A (en) * 1943-01-02 1945-06-05 Automatic Elect Lab Battery charging system
US2418235A (en) * 1943-07-10 1947-04-01 Gen Motors Corp Electric motor control

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2777923A (en) * 1952-08-08 1957-01-15 Ralph H Munson Relays
US2841032A (en) * 1952-11-14 1958-07-01 British Thomson Houston Co Ltd Operating mechanisms for electric circuit control devices
US3194917A (en) * 1963-03-04 1965-07-13 E & R Lab Service Corp Knee-action relay
US3530415A (en) * 1966-11-15 1970-09-22 Foerderung Forschung Gmbh Electrodynamic snap-acting actuator
US20130207755A1 (en) * 2012-02-13 2013-08-15 Stephan Lehmann Hinged armature bearing for magnetic tripping device
US9007154B2 (en) * 2012-02-13 2015-04-14 Siemens Aktiengesellschaft Hinged armature bearing for magnetic tripping device

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Publication number Publication date
NL71922C (de)
BE486545A (de)
CH295256A (fr) 1953-12-15
FR959293A (de) 1950-03-28

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