GB2302989A

GB2302989A - Electromagnetic relay

Info

Publication number: GB2302989A
Application number: GB9613490A
Authority: GB
Inventors: Kachu Ishizuka; Koichi Ishikawa; Toyohiko Akata; Tsuneo Horie; Tsutomu Hojo
Original assignee: Copal Electronics Co Ltd
Current assignee: Nidec Copal Electronics Corp
Priority date: 1995-06-30
Filing date: 1996-06-27
Publication date: 1997-02-05
Also published as: FR2736201A1; GB9613490D0; DE19625848A1; JPH0973849A; CN1144392A

Description

TITLE OF THE INVENTION

Electromagnetic relay 2302989 BACKGROUND OF THE INVENTION

The present invention relates to an electromagnetic relay of balance armature system, especially to a polar electromagnetic relay which can prevent bouncing.

Conventionally, those shown in Fig. 6 9 through 7 2 are available as an electromagnetic relay. This kind of electromagnetic relay consists of electromagnet block 6 2 composed of an iron core 6 4 having magnetic poles 7 1, 7 1 at both sides thereof. on which a coil 6 9 is wound, a permanent magnet 7 2, an armature block 7 3. a housing 5 1, and a casing 8 2 - The armature block 7 3 is provided with an armature 7 5, an insulative supporting member 7 9 attached to the underside of the armature 7 5. and a movable contact spring 7 6 secured at the insulative supporting member 7 9. The movable contact spring 7 6 is disposed upward of a fixed contact junction part 5 7 protruding from the bottom of the housing 5 1. Thus, the armature 7 5 and movable contact spring 7 6 are made integral with each other by the insulative supporting member 7 9, and the supporting spring 7 8 extends from inside the insulative supporting member 7 9 in the direction perpendicular to the lengthwise center of the movable contact spring 7 6 and is accommodated and fixed inside the side wall 5 2 of the housing 5 1. If the coil 6 9 is excited in an predetermined direction. the armature 7 5 is caused to inversely rock between the magnetic poles 7 1, 7 1 in a state integral with the movable contact spring 7 6 via the insulative supporting member 7 9.

centering around the core of the supporting spring 7 8. The respective terminals of common terminal 5 8, fixed contact terminal 5 6, coil terminal 6 0, etc. are provided on the bottom of the housing 5 1. 8 2 is a casing which is outwardly fitted to the housing 5 1. Said armature block 7 3 and electromagnet block 6 2 are attached to the housing 5 1.

The housing 5 1 has a side wall 5 2 and is roughly like a box, the upper side of which is open. The housing 5 2 is divided into a coil accommodation chamber 5 3 and an armature accommodation chamber 5 4 by a partition wall 5 1 a. and one end of each of the respective terminals of fixed contact terminal 5 6, common terminal 5 8, and coil terminal 6 0, which is formed to an predetermined shape by press- working conductive thin plate made of copper alloy, etc. are disposed so that they protrude from the bottom of the housing 5 1 and a group of these terminals is fixed together with insertion of synthetic resin. etc. One end of the fixed contact terminals 5 6 protrudes from the underside of the housing 5 1 and the other end thereof is disposed at each of the four comers of the armature accommodation chamber 5 4. whereas a fixed contact 5 5 made of a bulky precious metal tip is electrically welded to the upper side thereof in order to secure electrical connection with the fixed contact terminal 5 6.

One end of the common terminal 5 8 protrudes from the underside of the housing, and the end thereof is disposed at the lengthwise center of the side wall of the armature accommodation chamber 5 4 and at the center of the partition wall 5 1 a, whereby the common terminal junction part 5 9 is constituted. A supporting spring 7 8 of the armature block 7 3 described later is fixed to the common terminal junction part 5 9 by electric welding.

One end of the coil terminal 6 0 protrudes from the underside of the housing 5 1 and the other end thereof is provided to protrude from the concave portion of the side wall of the coil accommodation chamber 5 3, whereby'the coil terminal junction part 6 1 is constituted. A coil leadout terminal 6 8 of the electromagnet 6 2 described later is fixed to the coil terminal junction part 6 1 by electric welding.

The electromagnet block 6 2 consists of an electromagnet part 6 3 and a permanent magnet 7 2. The electromagnet part 6 3 is fin-ther composed of an iron core 6 4, coil 6 9 and coil lead- out terminals 6 8 - The iron core 6 4 is made of a magnetic substance such as electromagnetic mild iron and is formed to be roughly channel- shaped, wherein a spool 6 6 made of a molded member such as synthetic resin is provided at the intermediate portion thereof, and a flange 6 7 made of a molded member such as synthetic resin is also provided at the end of the spool 6 6. Both ends of the iron core 6 4 protrude sideward from the flange 6 7 to constitute a magnetic pole 7 1.

The coil lead- out terminals 6 8 are made of a conductive metallic materiaL formed to be roughly channel- shaped and respectively provided so as to protrude from the flange 6 7. One end of the coil lead- out terminal is fixed to the coil terminal junction part 6 1 of the housing 5 1 by electric welding, whereby electrical connection with the coil terminal 6 0 is secured.

A coil 6 9 is wound onto the spool 6 6 secured at the intermediate portion of the iron core 6 4, wherein the coil lead- out line 7 0 is fixed to the other end of the coil lead- out terminal 6 8 by soldering, and is electrically connected to the cod terminal 6 0 via the coil lead- out terminal 6 8.

The permanent magnet 7 2 is roughly plate- like, and is magnetized so that both ends thereof are of the same pole and the middle part thereof is of the other different pole, and is caused to intervene between the magnetic poles 7 1, 7 1 which are the ends of the iron core 6 4.

Fig. 7 3 through Fig. 7 6 show a conventional armature block 7 3.

The armature block 7 3 consists of an armature 7 5, movable contact 7 7, movable contact spring 7 6, supporting spring 7 8, and insulative supporting member 7 9.

The armature 7 5 is made of a soft magnetic material such as electromagnetic mild iron and is formed to be roughly plate- like. The movable contact spring 7 6 is made of a conductive metallic material such as a copper alloy thin plate, etc. The movable contact spring 7 6 is formed integral with the armature 7 5, downwards thereof, by an insulative supporting member 7 9 made of an insulative material such as synthetic resin, etc., which is disposed in parallel with the armature 7 5. A movable contact 7 7 made of a bulky precious metal tip is fixed to both ends of the movable contact spring 7 6 by electric welding, whereby the same is electrically connected to the common terminal 5 8 by a supporting spring 7 8 described later.

The supporting spring 78 is formed mechanically and electrically integral with the movable contact 7 6, extends from the lengthwise center of the movable contact spring 7 6 in the direction perpendicular thereto, and is fixed by electric welding to the common terminal junction part 5 9 disposed at the lengthwise center of the armature accommodation chamber 5 4 of the housing 5 1 -and at the center of the partition wall 5 1 a, whereby electrical connection with the common terminal 5 8 is secured.

An electromagnetic force operates on the armature 7 5 by excitation of the coil 6 9 of electromagnet block 6 2. Therefore, if the coil 6 9 is excited in an predetermined direction, the armature 7 5 is caused to inversely rock via the insulative supporting member 7 9 relative to the magnetic poles 7 1, 7 1 of the iron core 6 4 centering around the supporting spring 7 8 in such a state that the movable contact spring 7 6 and armature 7 5 are made integral with each other.

A casing 8 2 is made of an insulative substance such as synthetic resin, etc., and is formed to be roughly box- like. The casing 8 2 is outwardly fitted to the housing 51 in which the armature block 7 3 and electromagnet block 6 2 are provided.

There are the following problems in a conventional electromagnetic relay of a balance armature system.

- In a case where the electromagnetic relay is actuated. a collision occurs between the armature 7 5 of the armature block 7 3 and the magnetic pole 7 1 of the electromagnet block 6 2, whereby impact vibrations are produced at the armature 7 5. This state is described in detail with reference to Fig. 7 7.

(a) shows such a state that the armature 7 5 a is magnetically attracted by one magnetic pole 7 1 a of the electromagnet block 6 2 and the movable contact 7 7 a is brought into contact with the fixed contact 5 5 a (not illustrated) in a stabilized state.

Herein, the following description is based on the assumption that both ends of the permanent magnet 7 2 are magnetized to be N poles and the middle portion thereof is magnetized to be an S pole. In a case where both the ends thereof are magnetized to be S poles and the middle portion thereof is magnetized to be an N pole, the direction of magnetic flux m the following description is completely reversed, but the actions thereof remain identical to the description below.

Due to the magnetic flux A from the permanent magnet 7 2 flowing through the armature 7 5 a via the magnetic pole 7 1 a. the armature 7 5 a is nagnetically attracted to the magnetic pole 7 1 a. whereby the armature 7 5 is stably retained as shown in Fig. 7 7 (a).

Here, if electric current is caused to flow to the coil 6 9 so that the magnetic flux flows in the direction of the magnetic pole 7 1 a from the armature 7 5 a, the magnetic flux A from the permanent magnet 7 2 is counterbalanced by the magnetic flux C (which is flowing inside the iron core 6 4) from the coil 6 9 between the armature 7 5 a and the magnetic pole 7 1 a, whereby the magnetic attraction force between the armature 7 5 a and the magnetic pole 71 a is decreased.

Simultaneously, by causing electric current to flow to the cod, the magnetic attraction force between the armature 7 5 b and the magnetic pole 7 1 b, which is produced by the magnetic flux C generated toward the armature 7 5 b from the other magnetic pole 7 1 b and the magnetic flux B oriented from the permanent magnet 7 2 to the armature 7 5 b via the magnetic pole 7 1 b. is increased, wherein if this magnetic attraction force exceeds the magnetic attraction force between the armature 7 5 a and the magnetic pole 7 1 a, the armature 7 5 b is attracted to the other magnetic pole 7 1 b to cause the armature 7 5 to be inversed (See Fig. 7 7 (b)).

(b) shows the moment when the armature 7 5 is inversed by excitation of the coil 6 9 of the electromagnet block 6 2 and the armature 7 5 b is brought into collision with the other magnetic pole 7 1 b. At this time, since the kinetic energy by which the armature 7 5 b is inversed is not able to be absorbed between the armature 7 5 and magnetic pole 7 lb. impact vibrations are produced at the armature 7 5. The state of generation of these impact vibrations is shown in (c) and (d).

(c) shows a state where the armature 7 5 a is most dissociated from the magnetic pole 7 1 a by impact vibrations due to collision of the armature 7 5 b with the magnetic pole 7 1 b.

(d) shows a state where the armature 7 5 a is drawn near the magnetic pole 7 1 a, which is the state next to that of above (c).

Herein. the one- dot dashed lines shown in (c) and (d) show a stabilized position of the armature 7 5 at a standstill. The impact vibrations are continued. gradually reducing the vibration magnitude of the armature 7 5, and finally the armature 7 5 is stabilized and stands still at the position shown with the one- dot dashed line.

Thus, since in a conventional electromagnetic relay the armature 7 5 is brought into collision with the magnetic pole 7 1 when the armature 7 5 is caused to inversely rock when operating the relay, impact vibrations are transitionally produced at the armature 7 5, whereby the following problems occur.

(1) The movable contact spring 7 6 is made integral with the armature 7 5 by an insulative supporting member 7 9. and by excitation of the coil 6 9 of the electromagnet block 6 2 when operating, the armature 7 5 is caused to inversely rock and is alternately brought into contact with the magnetic poles 7 1, 7 1 of the electromagnet block 6 2, centering around the supporting springs 7 8, 7 8 which extend from the lengthwise center of the movable contact spring 7 6 in the direction orthogonal thereto.

However, as the armature 7 5 is brought into collision with the magnetic pole 7 1, said transitional impact vibrations are produced until the armature 7 5 is stabilized, and said impact vibrations are transmitted to the movable contact spring 7 6 and supporting spring 7 8 - Fig. 7 8 is a cross- sectional view of the peripheries of the supporting spring 7 8 illustrated in Fig. 7 7 when they are observed from the side thereof, and (a), (b). (c) and (d) correspond to each other. As understood from these drawings, (a) illustrates a stabilized state of the supporting spring 7 8, wherein stabilization is obtained with the end portion of the supporting spnng 7 8 fixed at the upper part of the common terminal junction part 5 9 of the housing 5 1. In (c). since the supporting spring 7 8 is displaced downward, and the armature 7 5 is drawn near the fixed contact 5 5 side, the deflection amount of the movable contact spring 7 6 is, increased in comparison with the stabilized state. In (d), to the contrary, since the supporting spring 7 8 is displaced upward and the armature 7 5 is dissociated from the fixed contact 5 5 side, the deflection of the movable contact spring 7 6 is decreased in comparison with the stabilized state. As a result, the contacting pressure between the fixed contact 5 5 and the movable contact 7 7 is accordingly changed, especially in (d) the contacting resistance between the contacts is increased by reduction of the contacting pressure between the fixed contact 5 5 and mo-,able contact 7 7, and at the same time, in a remarkable case, the contact between the fixed contact 5 5 and the movable contact 7 7 is not sufficient to cause them to be dissociated from each other.

Thus, while the armature 7 5 is vibrating by impacts when the electromagnetic relay operates, a so- called bounce phenomenon occurs, resulting from intermittent opening and closing of the fixed contact 5 5 and movable contact 7 7. When the deflection of the movable contact spring 7 6 is decreased. the contacting pressure is also reduced. Therefore, the armature 7 5 is in such a state that the same is easily influenced by external disturbance. For this reason, it is necessary to provide the circuit with a certain countermeasure in order to prevent erroneous operations in the circuits while such a.bounce phenomenon is being generated. Furthermore, in the meantime, since the relay does not completely function as a switching circuit, such an electromagnetic relay is not able to be used in a device which needs a high speed switching feature.

(2) In this case, precious metal on the contact surface may be evaporated or transferred due to discharge produced through closing and opening of the contacts under the current and voltage conditions by which an arc discharge may be generated. and the contact surface may be deformed if the contact is opened and closed many times. Therefore, a bounce phenomenon is produced when opening and closing the contacts. Furthermore, electric discharge is continued while the bounce phenomenon is generated.

Accordingly, the contact life cycle is shortened.

(3) Essentially. the armature 7 5 is caused to inversely rock alternately, confronting the magnetic poles 7 1, 7 1, centering around the supporting spring 7 8 Therefore, the supporting spring 7 8 is subject to twisting deformation.

However, once impact vibrations are produced at said armature 7 5, deformation due to bending and tension is further given to the supporting spring 7 8 in addition to the twisting deformation as shown in Fig. 7 8. Since impact vibrations of the armature 7 5 are produced when the supporting spring 7 8 is subject to the maximum twisting deformation, the maximum stress acting inside the supporting spring 7 8 is made greater in comparison with a case of the twisting deformation. Therefore, the durability (life) of the supporting spring 7 8 is shortened in cases where the same is repeatedly used.' Furthermore, since impact vibrations are generated whenever ging the electrical contacts, a number of deformations due to bending and tension are produced for one-7 time contact changing operation, whereby the nilm r of times of repetition of deformation acting on the supporting spring 7 8 is increased, and the durability (life) thereof is also shortened.

(4) Although a magnetic residual gap is formed by a non- magnetic plated layer or non- magnetic metallic plate between the armature 7 5 and the magnetic pole 7 1 in order to adjust the magnetic attraction force of the armature 7 5 and magnetic pole 7 1, such non- magnetic plated layer or non- magnetic metallic plate which constitutes the magnetic residual gap may be worn by impact vibrations of the armature 7 5.

If the contact surface of the armature 7 5 with the magnetic pole 7 1 is observed when impact vibrations are produced at the armature 7 5, a relative movement of a remarkably small magnitude in response to the impact vibrations of the armature 7 5 is carried out between the armature 7 5 and magnetic pole 7 1 resulting in a micromotion wear on the contact between the armature 7 5 and magnetic pole 7 1 whereby minute powder is produced due to wearing. Since this minute wearing powder is adhered to the surface of the movable contact 7 7 and fixed contact 5 5. resulting in defective contact, the contact life will be shortened.

Furthermore, as the magnetic residual gap formed between the armature 7 5 and magnetic pole 7 1 due to friction is decreased, the operating properties may change due to an increase in the operating voltage and/or a lowering of the returning voltage, thereby causing the life of the electromagnetic relay to be shortened.

The respective terminals of fixed contact terminal 5 6, common terminal 5 8. coil terminal 6 0, etc., and fixed contact 5 5 are provided in the housing 5 1, and the respective terminals of the fixed contact terminals 5 6, common terminal 5 8 and coil terminal 6 0. etc., which are formed by press- working a conductive thin plate, such as copper alloy etc. to an predetermined shape are insert- molded with a molding material such as synthetic resin, etc. so that one end thereof protrudes from the underside of the housing 5 1.

The fixed contact 5 5 is formed by electrically welding a bulky precious metal tip to the fixed contact junction portion 5 7 and the movable contact 7 7 is formed by electrically welding a bulky precious metal tip to the end part of the movable contact spring 7 6. However, especially, since the fixed contact 5 5 is formed by electrically welding a bulky precious metal tip to the fixed contact junction part 5 7, the contact height may be made uneven, resulting from the fact that the terminal shape is complicated and the terminal is insert- molded. If the contact height is made uneven, the contacting pressure between the fixed contact 5 5 and movable contact 7 7 differs at every contact, whereby the contact properties are made uneven, and the distance between the fixed contact 5 5 and movable contact 7 7 becomes uneven. Therefore, the state of said bounce phenomenon will differ at every contact, and it will be very difficult to carry out adjustments for the capacity of electromagnetic relays.

Furthermore, there is such a problem that according to the state of electric welding of a bulky precious metal tip, the contact height may change and the contacting pressure is made uneven.

Still furthermore, if the welding state is not sufficient. the thermal resistance between the fixed contact 5 5 and the fixed contact junction part 5 7 and between the movable contact 7 7 and the movable contact spring 7 6 is made greater, especially, if the electromagnetic relay is used under such a condition that an arc discharge is generated, and the contact wearing will be remarkable, thereby causing such a problem to occur that the contact durability (life) is reduced.

Additionally, if it is attempted to achieve a sufficient welded state, the temperature of a welding part is increased when welded the same, thereby causing the movable contact spring 7 6 and fixed contact junction part 5 7 to be deformed. and there will occur such a problem that the contact height is made uneven.

13 - SUMbMY OF THE ITSIVENTION It is therefore an object of the invention to provide a high performance and long- fife electromagnetic relay which can prevent a bounce phenomenon from occurring, increase the durability (life) in the repeated movement of a supporting spring, minimize the micromotion wear on the contact surface between the armature and magnetic poles, prevent changes of the operating characteristics due to changes of a magnetic residual gap and prevent defective contact of the contacts due to an adhering of powder due to wearing onto the contacts, obtain a stabilized contacting press ure with the contact heights made even, and secure a long life of contacts even under a discharge condition.

In order to achieve the above object, the invention constitutes an electromagnetic relay comprising: an electromagnet block comprising of an iron core on which a coil is wound. and a permanent magnet; an armature block comprising of an armature, a movable contact spring, an insulative supporting member, and a supporting spring extending fromtthe lengthwise center of the movable contact spring in the diretion perpendicular thereto and fixed to a housing, in which the armature and movable contact spring are made integral with each other by the insulative supporting member. ' which can inversely rock between a pair of magnets,v confronting the electromagnet block. centering around the supporting spring-, the housing having a common terminal, and fixed contact terminal and coil terminal, and to which the electromagnet block is attached; and a casing outwardly fitted to the housing, wherein a stopper is provided, which regulates the upward or downward displacement of the supporting spring. which displacement is generated by rocking of the armature.

Furthermore, the invention constitutes an electromagnetic relay comprising-. an electromagnet block comprising of an iron core on which a coil is wound. and a permanent magnet; an armature block comprising of an armature, a movable contact spring, an insulative supporting member, and a supporting spring extending from the center of the movable contact spring in the direction, perpendicular thereto and fixed to a housing; the housing being provided with a common terminal, a fixed contact terminal and a coil terminal, to which the electromagnet block and armature block are attached, wherein a one-way linking means is provided, which causes the armature and movable contact spring to inversely rock, confronting the magnetic poles of the electromagnet block centering around the supporting spring in such a state that the armature and movable contact spring are formed to be separated via an insulative supporting member.

Furthermore, the invention constitutes an electromagnetic relay which is provided with a one-way linking means, wherein a contacting pressure stabilizing mechanism is provided, which consists of a magnetic flux condensing member or an engaging piece to optimize the contacting pressure between the movable contact and the fixed contact.

Furthermore, the invention constitutes an electromagnetic relay provided with a displacement stopper which regulates the upward or downward displacement of the supporting spring due to the armature displacement resulting from a magnetic attraction force of said magnetic flux condensing member.

Furthermore, the invention constitutes an electromagnetic relay in which a plastic sheet is caused to intervene between the armature and the magnetic poles.

Additionally, said electromagnetic relay is constituted by providing the housing with an insulative substrate made of ceramic or glass-coated metal, a fixed contact made of a sinter-molded thick film formed on the upper surface of the insulative substrate, an armature block, and a fixing portion at which the electromagnet block is fixed. and providing the insulative substrate with a coil terminal, common terminal, and fixed contact terminal on the underside thereof.

Still furthermore, the invention constitutes an electromagnetic relay in which the movable contact formed at both ends of the movabi e contact spring is made of a sinter- molded thick film paste.

As described above. an electromagnetic relay provided with a movable contact spring made integral with an armature and insulative supporting member causes an attraction force to operate on roughly the end portion of the armature at the side thereof which is not in contact with a magnetic pole by magnetizing the coil so that the attraction force of the permanent magnet operating on the magnetic pole of the electromagnet at the side thereof which is in contact with the armature is weakened and the attraction force of the - 16 permanent magnet operating on the magnetic pole at the other side is strengthened, whereby the armature is caused to inversely rock, centering around the supporting spring, when electric current flows, thereby causing the contact to be changed over. At this time, a collision occurs between the armature and the magnetic pole, and impact vibrations are generated, resultmg from the fact that the rocking energy of the armature is not completely absorbed. The impact vibrations are transmitted to the movable contact spring and supporting spring, whereby displacement is produced in the vertical direction at the supporting spring in addition to the twisting deformation.

However, since the displacement of the supporting spring in the vertical direction due to the impact vibrations is regulated by a stopper, the displacement amount of the supporting spring in the vertical direction is decreased, and the deflection of the movable contact spring is made constant, thereby the duration of generation of the impact vibration can be shortened.

Furthermore, in such a construction that the armature and.movable contact spring are divided and separated from each other via the insulative supporting member, since the armature is constructed so as to inversely rock, impact vibrations of the armature are not transmitted to the movable contact spring and supporting spring even though the impact vibrations are generated by the collision between the armature and the magnetic pole. Therefore, the supporting spring is not displaced in the vertical direction, and the deflection of the movable contact spring is made constant.

Still fin-thermore, since a plastic sheet is caused to intervene between the armature and the magnetic pole, the impact vibrations due to collision between the armature and the magnetic pole is absorbed by the plastic sheet, the time of generation of the impact vibrations of the armature is shortened, and at the same time no powder due to micromotion wear between the armature and the magnetic pole is generated.

In addition, since the movable contact is formed of a sinter-molded body of thick film paste, and the housing is composed of an insulative substrate made of ceramic or glass-coated metal and a fixed contact made of a sinter-molded body of thick film paste, which is formed at the upper part of the insulative substrate, the height of the contacts are made uniform and made free from any unevenness, and especially, in a case of an electromagnetic relay in which a plurality of contacts are formed, the contacting pressure between the respective fixed contacts and movable contacts is made constant, whereby the distance between the respective fixed contacts and movable contacts are made constant.

In view of the shortcomings and problems described above, the present invention can eliminate these shortcomings and problems.

From the above description, in an electromagnetic relay comprising an electromagnet block, armature block, a housing having said electromagnet block and armature. and a casing externally attached to the housing, since a stopper which regulates upward or downward displacement of the supporting spring, which displacement is generated along with the rocking of the armature, is adopted, an electromagnetic force is generated atmagnetic poles by exciting the coil of the electromagnet block and the armature is attracted by said electromagnetic force. Therefore it is possible to attenuate the impact vibrations of the armature by regulating the upward or downward Aisplacement of the supporting spring, which is generated by impact vibrations occurring between the armature and magnetic poles when the armature is caused to inversely rock, the bouncing prevented from occurring, and the durability (fife) of the supporting spring can be increased.

Still furthermore, the contacts are changed over at a high speed since it is possible to prevent the bouncing from occurring. Therefore, an electromagnetic relay according to the invention is applied to devices in which high- speed switching is requisite. Still furthermore, since the bouncing can be prevented from occurring, it is possible to increase the durability (life) of the contacts even in the conditions of generating electric discharges.

In an electromagnetic relay comprising an electromagnet block, armature block, a housing having said electromagnet block and armature, and a casmg externally attached to the housing, by causing the movable contact spring and armature to inversely rock beiween a pair of magnetic poles centering around the supporting spring via a one-way linking means which allows the displacement to be transmitted in one direction along with the movements of the armature, the impact vibration in the direction along which the armature is most dissociated from its stabilized state, of impact vibrations generated by collision between the armature and the magnetic pole, is not transmitted to the movable contact spring and supporting spring. Therefore, it is possible to reduce the bouncing from occurring and possible to increase the durability (life) of the supporting spring.

By employing a contacting pressure stabilizing mechanism in addition to the one-way linldng means. the engagement of the one-way linking means when the movable contact is brought into contact with the fixed contact is strengthened. an predetermined deflection can be obtained. and a much higher contacting pressure can be obtained. Therefore, it is possible to further stabilize the contacting resistance.

Since. in addition to the one-way linidng means, a contacting pressure stabilizing mechanism comprising of a magnetic flux condensi member is provided. and Ituther a displacement stopper. which regulates upward or downward displacement of the supporting spring along with the upward or downward displacement of the armature by a magnetic attraction force produced by the magnetic flux condensing member, is provided in such a state that the same is m contact with or slightly apart from the upper part or lower part of the supporting spring. the durability (fife) of the supporting spnng can be much increase& At the same time, a more stab contacting pressure can be obtained, and it is possible to prevent the bouncing of contacts from occurring.

It is possible to absorb impact vibrations generated when causing the armature to inversely rock, by causing a non-magnetic sheet such as a plastic sheet member. etc. to intervene between the armature and magnetic poles. and it is possible to minimize the impact sound due to impact vibrations - 20 of the armature. Therefore, it is possible to shorten the generating time of impact vibrations.

Furthermore, the effect of preventing the bouncing from occurring is much increased, and it is possible to further increase the durability (life) of the supporting spring, and at the same time it is possible to prevent powder due to micro wearing from being generated. Therefore, it possible to lengthen the service life of the contacts.

Stiff furthermore it is easier to adjust the magnetic residual gap by forming the magnetic residual -gap with a plastic sheet, and the unevenness is minimized.

Since the housing is provided with an insulative substrate made of ceramic or glass-coated metal, a fixed contact sinter-molded with thick film paste, which is formed on the upper part of the insulative substrate, and an attaching portion at which the armature block and electromagnetic block are provided, and finther equipped with a coil terminal, common terminal, and fixed contact terminal at the lower part of the insulative substrate. it is much easier to adjust the height of the fixed contacts, the mass production efficiency thereof is much increased with the unevenness thereof minimi ed, and it is easy to change the terminal array.

Furthermore, since the thermoelectromotive force thereof is decreased, an electromagnetic relay according to the invention can be used for small signal circuits, and as the thermal dissipation is superior, it is possible to lengthen the durability (fife) of contacts even though usage happens in such a state where an arc discharge occurs.

Especially, in an electromagnetic relay having a number of contacts, the contacting pressure among the respective contacts is stabilized, and the operation timing is synchronized, whereby the reliability of the electromagnetic relay is further increased.

Still finthermore, it is easy to form a microstrip line and coplanar line by using a ceramic substrate. and if the fixed contact lead portion and common terminal lead portion, which are signal lines, are formed with a microstrip line or coplanar line, it is possible to obtain an electromagnetic relay of superior high frequency characteristics.

Since an electromagnetic relay is constituted with through holes formed at the insulative substrate and by securing electrical connections through these through holes between components provided on the upper surface and the lower surface of the insulative substrate, electrical connections between the upper and lower surfaces of the insulative substrate is made easier. thereby causing the mass production efficiency to be much improved.

Since an electromagnetic relay is constituted by forming a movable contact with sinter-molded, thick film paste at both the ends of the movable contact spring, the thermal resistance between the movable contact and movable contact spring is minimized, whereby it is possible to lengthen the durability (Iffe) of contacts even if the same are used under the condition of generating an arc discharge.

Further details and advantages of this invention will be seen in the - 22 accompanying drawings and following description of preferred embodiments.

SUMMARY OF THE DRAWINGS

Fig. 1 is a plan view of a first preferred embodiment of the invention.

Fig. 2 is a sectional view taken along the line II- II in Fig. 1.

Fig. 3 is a cross- sectional view taken along the line III- HI in Fig. 1 Fig. 4 is a cross- sectional view of a second preferred embodiment of the invention.

Fig. 5' is a cross- sectional view of a third preferred embodiment of the invention Fig. 6 is a plan view of a fifth preferred embodiment of the invention.

Fig. 7 is a sectional view taken along the line VII- VII in Fig. 6.

Fig. 8 is a sectional view taken along the line VIII- VIII in Fig. 6.

Fig. 9 is a plan view of an armature block according to the ffth preferred embodiment of the invention.

Fig. 10 is a front elevation view of the armature block according to the fifth preferred embodiment of the invention.

Fig. 11 is a sectional view taken along the line M-)g in Fig. 9 - Fig. 12 is a bottom view of the armature block according to the fifth preferred embodiment of the invention.

Fig. 13 is a view for explaining the actions of the armature according to the fM preferred embodiment of the invention.

Fig. 14 is a view showing the contact operating state of a conventional example and the contact operating state of the fifth preferred embodiment of the invention.

Fig. 15 is a plan view of a sixth preferred embodiment of the invention.

Fig. 16 is a sectional view taken along the fine XVI- XVI in Fig. 15 Fig. 17 is a sectional view taken along the line M- M in Fig. 15.

Fig. 18 is.a plan view of an armature block according to the sixth preferred embodiment of the invention.

Fig. 19 is a front elevational view of the armature block according to the sixth preferred embodiment of the invention.

Fig. 2 0 is a sectional view taken along the line XX- XX in Fig. 18.

Fig. 2 1 is a bottom view of the armature according to the sixth preferred embodiment of the invention.

Fig. 2 2 is a view for explaining the armature according to the sixth preferred embodiment of the invention.

Fig. 2 3 is a view showing the engaged state of a one-way linking means in a case where the contacting pressure of the fifth preferred embodiment of the invention is increased.

Fig. 2 4 is a view showing the engaged state of a one-way linldng means in a case where the contacting pressure of the sixth preferred embodiment of the invention is increased.

Fig. 2 5 is a plan view of a seventh preferred embodiment of the invention.

Fig. 2 6 is a sectional view taken along the fine KM- KM in Fig. 2 5.

Fig. 2 7 is a sectional view taken along the line XXVH- XXVII in Fig. 2 5.

- 24 Fig. 2 8 is a cross- sectional view of major parts showing a first contacting pressure stabilizing mechanism according to the invention.

Fig. 2 9 is a view for explaining the actions of an armature in which the first contacting pressure stabilizing mechanism of the invention is adopted.

Fig. 3 0 is a cross- sectional view of major parts showing a second contacting pressure stabilizing mechanism of the invention.

Fig..3 1 is a cross- sectional view of major parts showing a third contacting pressure stabilizing mechanism of the invention.

Fig. 3 2 is a view for explaining the actions of an armature in which the third contacting pressure stabilizing mechanism of the invention is adopted.

Fig. 3 3 is a cross- sectional view of major parts showing a fourth contacting pressure stabilizing mechanism of the invention.

Fig. 3 4 is a plan view of an eleventh preferred embodiment of the invention.

Fig. 3 5 is a sectional view taken along the line MV- MV in Fig. 3 4.

Fig. 3 6 is a sectional view taken along the line MVI- XXXVI in Fig. 3 4.

Fig. 3 7 is cross- sectional view of major parts showing a fifth contacting pressure stabilizing mechanism of the invention.

Fig. 3 8 is a cross- sectional view of major parts showing a sixth contacting pressure stabilizing mechanism of the invention.

Fig. 3 9 is a cross- sectional view of major parts showing a seventh contacting pressure stabilizing mechanism of the invention.

Fig. 4 0 is a cross- sectional view of major parts showing an eighth contacting pressure stabilizing mechanism of the invention.

Fig. 41 is a plan view of a fifteenth preferred embodiment of the invention.

Fig. 4 2 is a sectional view taken along the line W- XLE in Fig. 4 1.

Fig. 4 3 is a sectional view taken along the line XLIH- MH in Fig. 4 2.

Fig. 4 4 is a plan view showing a sixteenth preferred embodiment of the invention.

Fig. 4 5 is a sectional view taken along the line W- XU in Fig. 4 4.

Fig. 4 6 is a cross- sectional view taken along the line XLVI- XLM in Fig.

44.

Fig. 4 7 is a plan view showing a seventeenth preferred embodiment of the invention.

Fig. 4 8 is a front elevational view of the seventeenth preferred embodiment of the invention.

Fig. 4 9 is a sectional view taken along the line XLEK- XLEK in Fig. 4 7.

Fig. 5 0 is a plan view showing a housing according to the seventeenth preferred. embodiment of the invention.

Fig. 5 1 is a front elevational view showing the housing according to the seventeenth preferred embodiment of the invention.

Fig. 5 2 is a side elevational view showing the housing according to the seventeenth preferred embodiment of the invention.

Fig. 5 3 is a plan view of an armature block according to the seventeenth preferred embodiment of the invention.

Fig. 5 4 is a front elevational view of the armature block according to the seventeenth preferred embodiment of the invention.

Fig. 5 5 is a plan view of an armature block provided with a block frame according to the seventeenth preferred embodiment of the invention.

Fig. 5 6 is a sectional view taken along the line LVI- WI in Fig. 5 5.

Fig. 5 7 is a plan view of a nineteenth preferred embodiment of the invention.

Fig. 5 8 is a cross- sectional view taken along the line LVIH- LVM in Fig. 57.

Fig. 5 9 is a sectional view taken along the fine LIX- LIX in Fig. 5 7.

Fig. 6 0 is a plan view showing a twentieth preferred embodiment of the invention.

invention.

Fig. 6 1 is a sectional view taken along the fine LM- LM in Fig. 6 0.

Fig. 6 2 is a sectional view taken along the line M- MH in Fig. 6 0.

Fig. 6 3 is a plan view of a twenty- first preferred embodiment of the Fig. 6 4 is a sectional view taken along the line MV- W9V in Fig. 6 3. Fig. 6 5 is a sectional view taken along the line M- M in Fig. 6 3.

Fig. 6 6 is a plan view of a twenty- second preferred embodiment of the invention.

Fig. 6 7 is a sectional view taken along the line LM- LM in Fig. 6 6. Fig. 6 8 is a sectional view taken along the line LMI- MW in Fig. 6 6. Fig. 6 9 is a disassembled perspective view of a conventional example.

Fig. 7 0 is a plan view of the conventional example.

27 - Fig. 7 1 is a sectional view taken along the line LKM- L= in Fig. 7 0. Fig. 7 2 is a sectional view taken along the line LM- UXII in Fig. 7 0.

Fig. 7 3 is a plan view of an armature block according to the conventional example.

Fig. 7 4 is a front elevational view of the armature block according to the conventional example.

Fig. 7 5 is a sectional view taken along the line LM- LM in Fig. 7 3.

Fig. 7 6 is a bottom view of the armature block of the conventional example.

Fig. 77 is a view for explaining the actions of the armature block of the conventional example.

Fig. 7 8 is a view for explaining the actions of a supporting spring of the conventional example.

- 28 DESCRHMON OF PREFERRED EMBODIMENTS OF THE IN'VENTION Hereinafter, preferred embodiments of the invention are described in detail with reference to the drawings attached herewith. In these preferred embodiments, members which are identical to those in the conventional example are given the same reference numbers, and the explanation of these same members is omitted hereinafter.

A first preferred embodiment of the invention is described by using Fig. I through Fig. 3 with reference to Fig. 7 0, Fig. 7 1, and Fig. 7 2 which describe the conventional example. 5 1 is a housing which has a side wall 5 2 and is like a box, the top surface of which is open. The housing 5 1 is divided into a coil accommodation chamber 5 3 and an armature accommodation chamber 5 4 by a partition wall 5 1 a and is provided with stoppers 2 4 a, 2 4 b described later.

Fixed contact terminal 5 6, common terminal 5 8, coil terminal 6 0, etc., which are formed to an predetermined shape by press- working a conductive thin plate of copper alloy are disposed in the housing 5 1 so that one end of each of the respective terminals is projected downward from the housing 5 1 bottom. wherein a group of these terminals is fixed with insertmolded synthetic resin, etc. One end of the fixed contact terminal 5 6 protrudes from the underside of the housing 5 1, and the other end thereof is disposed at each of the four comers of the armature accommodation chamber 5 4, and the fixed contact 5 5 made of a bulky precious metal tip is fixed to the upper part of the fixed contact terminal 5 6 by electrical welding to ensure electric connection therebetween.

One end of the common terminal 58 protrudes from the underside of the housing 5 1, and the other end thereof is disposed at the lengthwise center of the side wall of the armature accommodation chamber 5 4 and at the center of the partition wall 5 1 a, thereby causing a common terminal junction part 5 9 to be formed. A supporting spring 7 8 of the armature block 7 3 described later is fixed to the common terminal junction part 5 9 by electric welding.

The stoppers 2 4 a, 2 4 a which regulate the upward displacement of the supporting spring are made of insulative material such as synthetic resin, etc, and are provided to protrude from the lengthwise center of the side wall of the armature accommodation chamber 5 4 and the center of the partition wall 5 1 a, so that they are brought into contact with or slightly apart from the lower part of the supporting spring 7 8.

Furthermore. the stoppers 2 4 b, 2 4 b which regulate the downward displacement of the supporting spring are made of insulative material such as synthetic resin, etc., and are provided to protrude from the lengthwise center of the side wall of the armature accommodation chamber 5 4 and the center of the partition wall 5 1 a, so that they are brought into contact with or slightly apart from the upper part of the supporting spring 7 8 (Fig. 3).

As already explained, the coil terminal 6 0 is provided so that one end thereof protrudes from the underside of the housing 5 1 and the other end thereof protrudes from the concave part of the side wall of the coil accommodation chamber 5 3, thereby causing the coil terminal junction part 6 1 to be formed. The coil lead- out terminal 6 8 of the electromagnet block 6 2 described later is fixed to the coil terminal junction part 6 1 by electrical welding.

The electromagnet block 6 2 is composed of an electromagnet 6 3 and a permanent magnet 7 2. The electromagnet 6 3 is further composed of an iron core 6 4, coil 6 9 and coil lead- out terminal 6 8.

The iron core 6 4 is made of a magnetic substance of electromagnetic mild iron and is formed to be roughly channel- shaped, and at the intermediate part thereof a spool 6 6 made of a molded member of synthetic resin, etc. is provided, and the end portion of the spool 6 6 is provided with a flange 6 7 made of a molded member of synthetic resin, etc., wherein both ends of the iron core 6 4 protrude sideward from the flange 6 7, and the magnetic poles 7 1 are formed thereat.

The coil lead- out terminal 6 8 (Fig. 2) is made of conductive metal material And is formed to be roughly channel- shaped. The coil lead- out terminal 6 8 is provided so as to protrude from the flange 6 7.

wherein one end thereof is fixed to the coil terminal junction part 6 1 of the housing 5 1 by electrical welding to ensure electrical connection with the coil terminal 6 0.

The coil 6 9 is wound onto the spool 6 6 secured at the intermediate portion of the iron core 6 4, and the coil lead- out line 7 0 is - 31 soldered and fixed to the other end of the coil lead- out terminal 6 8, whereby the coil lead- out line 7 0 is electrically connected to the cod terminal 6 0 via the coil lead- out terminal 6 8.

The permanent magnet 7 2 is roughly plate- like. both the ends thereof are magnetized to the same pole, and the middle part thereof is magnetized to the other pole. wherein both the ends thereof are provided so as to intervene between the magnetic poles 7 1, 7 1 which are the ends of the iron core 6 4.

The armature block 7 3 is composed of an armature 7 5.

movable contact 7 7. movable contact spring 7 6, supporting 78, sprmg and insulative supporting member 7 9.

The armature 7 5 is made of magnetic material such as electromagnetic mild iron. etc. and is formed to be roughly plate- like.

The movable contact spring 7 6 is formed of conductive metallic material of copper alloy, etc. The movable contact spring 7 6 is mounted integral with the armature 7 5 downward thereof. by an insulative supporting member 7 9 made of insulative material such as synthetic resin. etc.

which is provided in parallel with the armature 7 5. The movable contact 7 7 made of a bulky precious metal tip is fixed to both the ends of the movable contact spring 7 6 by electrical welding and is electrically connected to the common terminal 5 8 via a supporting spring 7 8 described later.

The supporting spring 7 8 is formed mechanically and electrically integral with the movable contact spring 7 6, extends from the lengthwise center of the movable contact spring 7 6 in the direction perpendicular thereto, and is fixed by electrical welding to the common terminal junction part 5 9 disposed at the lengthwise center of the armature accommodation chamber 5 4 of the housing 5 1 and at the center of the partition wall 5 1 a, whereby electrical connection with the common terminal 5 8 is secured.

Furthermore, a casing 8 2 (not illustrated) is externally fitted to the housing 5 1 in which the armature block 7 3 and electromagnet block 6 2 are provided.

In an electromagnetic relay thus constructed according to the first preferred embodiment of the invention, if the coil 69 of the electromagnet block 62 is excited, an electromagnetic force is generated at the magnetic pole 7 1 to cause an attraction force to operate on the armature 7 5, whereby the armature 7 5 is caused to inversely rock, confronting the magnetic poles 7 1, 7 1 of the iron core centering around the supporting spring 7 8 - At this time, although impact vibrations are generated at the armature 7 5 as a transitional phenomenon by collision of the armature 7 5 with the magnetic pole 7 1 to cause the supporting spring 7 8 to be displaced in the vertical direction, the downward displacement of the supporting spring 7 8 is regulated by the stopper 2 4 a being brought into contact with the supporting spring 7 8. whereby it is possible to obtain stabilized contacting pressure, and it is possible to prevent bouncing from occurring. Furthermore, since deformations other than twisting of the supporting spring 7 8 are reduced, the durability (life) of the supporting spring 7 8 can be much increased. Still furthermore, the upward displacement of the supporting spring 7 8 is regulated by the stopper 2 4 b being brought into contact with the supporting spnng 7 8, whereby stabilized contacting pressure can be obtained, and it is possible to prevent bouncing from occurring. 'Merefore, since deformations other than twisting of the supporting spring 7 8 are reduced, the durability (life) of the supporting spring 7 8 can be much increased.

Since no bounce phenomenon is generated, the contact life cycle can be lengthened even under the conditions of current and voltage where arc discharge occurs.

Furthermore, the energy of impact vibrations is absorbed by the stoppers 24a, 24b, so that the generating duration of impact vibrations can be shortened.

Herein, although such a construction is adopted that the stoppers 24a, 24b are respectively provided so as to protrude from the lengthwise center of the side wall of armature accommodation chamber 5 4 and the center portion of the partition wall 5 1 a, only any one of them may be provided instead. In addition, it is possible to obtain the same effect if they are provided at the lower part and the upper part of the insulative supporting member 7 9, at the housing 5 1 and permanent magnet 7 2 located at the lower part or the upper part of the insulative supporting member 7 9, at the lower part and upper part of the supporting spring 7 8, and at the casing 8 2, etc.

Fig. 4 shows a second preferred embodiment of the invention, in which the stoppers 2 4 c, 2 4 d are provided on the bottom surface of the housing 5 1 and on the underside of the permanent magnet 7 2 while the insulative supporting member 7 9 is put therebetween.

In the second preferred embodiment of the invention, since the displacement of the armature block 7 3 in the vertical direction is reduced by the stoppers 2 4 c, 2 4 d, displacement of the supporting spring 7 8 in the vertical direction is accordingly regulated.

Fig. 5 shows a third preferred embodiment of the invention, wherein the stoppers 2 4 e, 2 4 f are provided at the underside and upper surface of the insulative supporting member 7 9, which has the same effect as that of the first or second preferred embodiment.

Furthermore, it is needless to say that these stoppers 2 4 e, 2 4 f are constructed integral with the insulative supporting member 7 9.

A fourth preferred embodiment is featured in that a plastic sheet is caused to intervene between the armature and the magnetic pole (Not illustrated).

A plastic sheet of, for example. polyethylene terephthalate, polyethylene naphthalate, polyimide, polyetherimide, polyphenylenesulfide, aramide, liquid polymer, etc. is caused to intervene between the armature 7 5 and the magnetic pole 7 1, thereby causing a magnetic residual gap to be formed.

In the preferred embodiment, although a polyimide film of 2 5 11 m thick is employed, the magnetic residual gap may be formed by combination with a conventional non- magnetic plated layer and non- magnetic metallic plate. In an electromagnetic relay thus constructed. since an impact due to a collision between the armature 7 5 and magnetic pole 7 1 which occurs when the armature 7 5 is caused to inversely rock, is absorbed by a plastic sheet which is an elastic substance, it is possible to shorten the generating duration of the impact vibrations. In comparison with the first preferred embodiment. the effect of preventing a bounce phenomenon can be increased.

and displacement other than a twisting of the supporting spring 7 8 is ftather. reduced. Therefore. displacement other than the twisting of the supporting spring 7 8 can be reduced to cause the durability (life) of the supporting spring 7 8 to be much increased.

Furthermore, m addition to the impact vibrations between the armature 7 5 and the magnetic pole 7 1 being absorbed, since there is no powder produced due to micromotion wear between the armature 7 5 and magnetic pole 7 1, it is possible to prevent defective contact of the contact points, which may be produced by powder due to wearing.

Furthermore. since the magnetic residual gap is not changed due to micromotion wearing, it is possible to prevent the operating characteristics from fluctuating due to an increase of the operating voltage and a lowering of the returning voltage.

In addition. it will be easy to adjust the magnetic residual gap by forming the magnetic residual gap with a plastic sheet, and the unevenness thereof can be much reduced.

36 Here, since said plastic sheet and armature are subject to impacts and relative micromotions are generated on the contact surface between the plastic sheet and armature, a crystalline high polymer is highly recommended as the material of the plastic sheet.

Furthermore, as the operation of an electromagnetic relay accompanies heating of the coil, it is also highly recommended that the plastic sheet has a heat resistant property of 12 0 " C or more. Polyimide is most preferable as a material capable of meeting these conditions.

Next, Fig. 6 through Fig. 8 show a fifth preferred embodiment of the invention. A movable contact spring 7 6. supporting spnng 7 8, armature 19, magnetic pole 7 1 and permanent magnet 7 2 are laminated in order from the housing 5 1 bottom, wherein a one-way linking means 3 2 a is composed of an engaging portion secured at the insulative supporting member 2 1 a and a portion to be engaged. which is secured at the armature 19, and the movable contact spring 7 6 and armature 19 are separated from each other and are composed so that they are able to operate independently via the insulative supporting member 2 1 a.

Fig. 9 through Fig. 12 shows an armature block 18 a of the fifth preferred embodiment according to the invention, wherein the insulative supporting member 21 a made of insulative material such as synthetic resin, etc, the cross- section of which is roughly channel- shaped, is insert- molded at the center of the movable - contact spring 7 6 together with the movable contact spring 7 6. An engaging piece 3 3 is formed on the upper surface of the side walls 2 1 c, 2 1 d which are free ends of the insulative supporting member 21 a. The supporting spring 7 8 which is electrically and mechanically integral

with the movable contact point 7 6 is formed so as to extend from the lengthwise center of the movable contact spring 7 6 in the direction perpendicular thereto, whereas the supporting spring 7 8 is fixed by electrical welding to the common termmal junction part 5 9 which is disposed at the lengthwise center of the armature accommodation chamber 5 4 of the housing 5 1 and at the center of the partition wall 5 1 a.

The armature 19 made of a soft magnetic material such as electromagnetic soft iron, etc., which is formed to be roughly plate-like, is disposed upward of the movable contact spring 7 6, and the armature 19 is provided with an opening 3 7 in which the side walls, 2 1 c, 2 1 d formed on the insulative supporting member 2 1 a are inserted. The side walls 2 1 c. 2 1 d of the insulative supporting member 2 1 a and the engaging piece 3 3 are inserted in and engaged with the opening 3 7. whereby the movable contact spring 7 6 and armature 19 are separated. Such a construction is herein called one-way linking means 3 2 a.

The magnetic pole 7 1 of electromagnetic magnet block 6 2 and the permanent magnet 7 2 are disposed upward of the armature 19.

The one-way linking means 3 2 a is constructed by the side walls 2 1 c, 2 1 d formed at the insulative supporting member 2 1 a, the cross- section of which is channel- shaped as described above, passing through the opening 3 7 formed at the armature 19 and the engaging piece 3 3 which is the engaging portion secured at the end portion of the side walls 2 1 c, 21 d bei engaged with the opening 3 7 which is the portion to be Ing engaged of the armature 19, whereby one end portion of the armature 19 is attracted by and retained at the magnetic pole 7 1 by an attraction force of the permanent magnet 7 2 in such a state that the engaging piece 3 3 is engaged with the opening 3 7 of the portion to be engaged.

In an electromagnetic relay of the fifth preferred embodiment thus constructed of the invention, an electromagnetic force is generated by exciting the coil 6 9 of the electromagnet block 6 2. an attraction force is caused to operate on the end portion of the armature 19 at the side which is apart from the magnetic pole 7 1, whereby the engaging piece 3 3 of the insulative supporting member 2 1 a engaged with the opening 3 7 of the portion to be engaged of the armature 19 at its side which is apart from the magnetic pole 7 1 is lifted up, and the insulative supporting member 21 a and the movable contact spring 7 6 which is integral with the insulative supporting member 2 1 a are caused to inversely rock between the magnefic poles 7 1, 7 1, centering around the supporting spring 7 8 secured to the housing 5 1.

Since the engaging piece 3 3 of the engaging portion which constitutes the one-way linking means 3 2 a is engaged with the opening 3 7 of the portion to be engaged and the armature 19 is retained by an attraction force of the permanent magnet 7 2, the armature 19 is caused to inversely rock between the magnetic poles 7 1, 7 1, centering around the supporting - 39 spring 7 8 together with the movable contact spring 7 6.

The actions of the armature 19 in the fifth preferred embodiment according to the invention are described. using Fig. 13, with reference to the actions (Fig. 7 7) of the conventional armature 7 5.

(a) shows a state where the armature 19 a is magnetically attracted by one magnetic pole 7 1 a of the electromagnet block 6 2 and the movable contact 7 7 a is in contact with the fixed contact 5 5 a (not illustrated) in a stabilized state.

Herein. if the coil 6 9 of the electromagnet block 6 2 is excited in such a direction that the magnetic attraction force between the armature 19 a and the magnetic pole 7 1 a is reduced and the magnetic attraction force between the armature 19 b and the magnetic pole 7 1 b is increased. the armature 19 b is magnetically attracted toward the other magnetic pole 7 1 b at the moment when the magnetic attraction force between the armature 19 b and magnetic pole 7 1 b exceeds the magnetic attraction force between the armature 19 a and magnetic pole 7 1 a. whereby the armature 19 is caused to inversely rock (See Fig. 13 (b)).

(b) shows the moment when the armature 19 is caused to inversely rock by excitation of the coil 6 9 of the electromagnet block 6 2 and the armature 19 b is brought into collision with the other magnetic pole 7 1 b.

At this time. since the kinetic energy with which the armature 19 is caused to inversely rock is not absorbed between the armature 19 b and the magnetic pole 7 5 b, impact vibrations are generated at the armature 19. The states of generating the impact vibrations are shown in (c) and (d) below.

(c) shows a state where the armature 19 a is most dissociated from the magnetic pole 7 1 a by the impact vibrations between the armature 19 b and the magnetic pole 7 1 b.

On the other hand, an opening 3 7 into which side walls 2 1 c, 2 1 d formed on the insulative supporting member 2 1 a are inserted is formed at the armature 19, and the side walls 2 1 c, 2 1 d of the insulative supporting member 2 1 a pass through the opening 3 7. The engaging piece 3 3 which is an engaging portion formed on the upper surface of the side walls 2 1 c, 2 1 d of the insulative supporting member 2 1 a is engaged with the portion to be engaged of the armature 19 to cause the armature 19 to be retained by attraction force of the permanent magnet 7 2, whereby a one-way linking means 3 2 a is constituted. Therefore, unless the portion to be engaged of the armature 19 lifts up the engaging piece 3 3 of the insulative supporting member 2 1 a, the action of the armature 19 is not transmitted to the movable contact spring 7 6.

Therefore. in this state. since the impact vibrations of the armature are not transmitted to the movable contact spring 7 6, etc. the supporting spring 7 8 is not displaced downward, differing from an armature 7 5 (See Fig. 7 7 (c)) of the conventional example, and it is possible for the movable contact 7 7 a to be brought into contact with the fixed contact 5 5 a (not illustrated) in a stabilized state.

(d) is the state which follows the state (c) and shows a state where the arma ture 19 a comes near the magnetic pole 7 1 a.

In this state, although the armature 19 a (See Fig. 13 (c)) which has been most dissociated from the magnetic pole 7 1 a by the impact vibrations is caused to come near the magnetic pole 7 1 a by the reaction thereof to the maximum, the Idnetic energy is low because the reaction is the inertia moment of only the armature 19 Therefore, the supporting spring 7 8 is scarcely displaced upward.

Thus, since the supporting spring 7 8 is not displaced downward and is scarcely displaced upward. it is possible to reduce the displacement other than a twisting of the supporting spring 7 8 and to reduce bouncing.

Furthermore. it is possible to increase the durability (life) of the supporting spring 7 8.

Still fin-thermore, it is possible to obtain the same effect if the engaging portion formed at the insulative supporting member 21 a and the portion to be engaged, which is formed at the armature 19. are inversely provided.

In addition, as described in the fourth preferred embodiment of the invention. since it is possible to absorb impact vibrations of the armature 19 by causing a plastic sheet to intervene between the armature and the magnetic pole, bouncing can be reduced, whereby the durability (life) of the supporting spring 7 8 can be increased.

Fig. 14 is a view showing the contact operating situation where the state of generating this bounce phenomenon is observed. In the same drawing, (1) and (5) show that electric current flows to the coil 6 9, (2) and (6) show states where the movable contact 7 7 b is in contact with the fixed contact 5 5 b, (3) and (7) show states where both the movable contacts 7 7 a, 7 7 b are not in contact with the fixed contacts 5 5 a. 5 5 b. and (4) and (8) show states where the movable contact 7 7 a is in contact with the fixed contact 5 5 a.

Furthermore, (3) and (7) also show a non- contacting state while changing the contacts, and the state of generating a bounce phenomenon.

As has been made clear from these drawings, in the fifth preferred embodiment of the invention, since the duration of generating the bouncing is very short, a quick and stabilized changeover of the contacts can be carried out.

Fig. 15 through Fig. 17 shows a sixth preferred embodiment of the invention, wherein a movable contact spring 7 6, supporting spring 7 8, magnetic pole 7 1, permanent magnet 17 and armature 2 0 are laminated in order from the bottom of the housing 5 1, and by an engaging portion provided at the end portion of the insulative supporting member 2 1 b and the portion to be engaged, which is notched at the armature 2 0, the side portions 2 1 e. 2 1 f of the insulative supporting member 2 1 b pass through openings 3 7 b. 3 7 b of the permanent magnet 17 to constitute a one- way linking means 3 2 b, thereby the movable contact spring 7 6 is separated from the armature 2 0 to cause them to operate independently.

Fig. 18 through Fig. 2 1 show an armature block 18 b of the 43 sixth preferred embodiment of the invention, in which an insulative supporting member 2 1 b made of insulative material such as synthetic resin, etc., the cross- section of which is made roughly channel- shaped, is insertmolded together with the movable contact spring 7 6 at the center of the movable contact spring 7 6, a circular column- like projecting portion 3 6 is formed on the upper surface of the side walls 2 1 e, 2 1 f which are free ends of the insulative supporting member 2 1 b, the cross- section of which is roughly channel-shaped.

Furthermore, the supporting spring 7 8 which is mechanically and electrically integral with the movable contact spnng 7 6 is formed so as to extend from the lengthwise center of the movable contact spring 7 6 in the direction orthogonal thereto, and is fixed by electric welding to the common terminal junction part 5 9 disposed at the lengthwise center of the armature accommodation chamber 5 4 of the housing 5 1 and at the center of the partition wall 5 1 a.

The magnetic pole 7 1 and permanent magnet 17 of the electromagnetic block 15 are disposed upward of the movable contact spring 7 6, and an opening 3 7 b into which a projecting portion 3 6 formed on the upper surface of the side walls 2 1 e, 2 1 f' of a channel- shaped insulative supporting member 2 1 b is inserted is formed at the permanent magnet 17.

An armature 2 0 made of a soft magnetic material such as electromagnetic soft iron and formed to be roughly plate- like is disposed upward of the magnetic pole 7 1 and permanent magnet 17, and a concave 44 - portion 3 5 engageable with the projecting portion 3 6 formed on the upper surface of the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b is formed at the underside of the armature 2 0.

The one-way linking means 3 2 b is composed of the projecting portion 3 6 of the engaging portion formed on the upper surface of the side walls 2 1 e. 2 1 f of the insulative supporting member 2 1 b and the concave. portion 3-5 of the portion to be engaged, which is formed at the armature 2 0.

The armature 2 0 is retained by an attraction force of the permanent magnet 17 with the projecting portion 3 6 engaged with the concave portion 3 5.

In an electromagnetic relay of the sixth preferred embodiment of the invention thus constructed, an electromagnetic force is generated at the magnetic pole 7 1 by exciting the coil 6 9 of the electromagnet block 15.

and an attraction force operates on the end portion of the armature 2 0 at the side thereof which is apart from the magnetic pole 7 1, whereby the concave portion 3 5 of the portion to be engaged. which is formed at the armature 2 0 at the side thereof which is apart from the magnetic pole 7 1, presses the projecting portion 3 6 of the engaging portion of the insulative supporting member 2 1 b which is engaged with the concave portion 3 5, and the insulative supporting member 2 1 b and the movable contact spring 7 6 which is made integral with the insulative supporting member 2 1 b are caused to inversely rock relative to the magnetic poles 7 1, 7 1 centering around the supporting spring 7 8 which is fixed to the housing 5 1 The engaging projecting portion 3 6 and the concave portion 3 5 of the portion to be engaged, which constitute the one-way finking means 3 2 b. are engaged with each other and retained by the attraction force of the permanent magnet 17. Therefore, they are caused to inversely rock, as described above, relative to the magnetic poles 7 1, 7 1 centering around the supporting spring 78, together with the armature 20 and the movable contact spring 76.

Herein, the actions of the armature 20 in the sixth preferred embodiment of the invention are explained, using Fig. 2 2, with reference to the actions (Fig. 7 7) of the conventional armature 7 5.

(a) shows a state where the armature 2 0 a is magnetically attracted to one magnetic pole 7 1 a of the electromagnet block 15 and the movable contact 7 7 a is in conta ct with the fixed contact 5 5 a (not illustrated) in a stabilized state.

Here, if the coil 6 9 of the electromagnet block 15 is excited in such a direction that the magnetic attraction force between the armature 2 0 a and magnetic pole 7 1 a is reduced and the magnetic attraction force between the armature 2 0 b and magnetic pole 7 1 b is increased, the armature 2 0 b is magnetically attracted to the other magnetic pole 7 1 b at the moment when the magnetic attraction force between the armature 2 0 a and magnetic pole 7 1 b exceeds that between the armature 2 0 b and magnetic pole 7 1 b, whereby the armature 2 0 is inversed (See Fig. 2 2 (b)).

(b) shows the state of the moment when the armature 2 0 b is brought into collision with the other magnetic pole 7 1 b by inverting of the armature 2 0 due to excitation of the coil 6 9 of the electromagnet block 15. At this time, since the kinetic energy which inversed the armature 2 0 can not be completely absorbed between the armature 2 0 b and magnetic pole 7 1 b, impact vibrations are brought at the armature 2 0. (c) and (d) below show the states where these impact vibrations are generated.

(c). shows a state where the armature 2 0 a is most dissociated from the magnetic pole 7 1 a by the impact vibrations between the armature 2 0 b and the magnetic pole 7 1 b.

On the other hand, a one- way linking means 3 2 b is constituted by retaining the armature 2 0 by the attraction force of the permanent magnet 17 in such a state that the projecting portion 3 6 of the engaging portion formed at the insulation supporting member 2 1 b is engaged with the concave portion 3 5 of the portion to be engaged, which is formed at the armature 2 0, whereby the operation of the armature 2 0 is not transmitted to the movable contact spring 7 6 unless the concave portion 3 5 of the portion to be engaged of the armature 2 0 presses the engaging portion 3 6 of the insulation supporting member 21 b.

Therefore, in this state. since the impact vibrations of the armature 2 0 are not transmitted to the movable contact 7 6, etc, the supporting spring 7 8 is not subject to any upward displacement. differing from the armature 7 5 (See Fig. 7 7 (c)). Therefore, the movable contact 7 7 a can be brought into contact with the fixed contact 5 5 a (not illustrated) in a stabilized state.

(d) is the next state of the above (c) and shows a state where the armature 2 0 a is drawn near the magnetic pole 7 1 a.

In this state, the armature 2 0 a (See Fig. 2 2 (c)) which has been most dissociated from the magnetic pole 7 1 a by the impact vibrations is most drawn near the magnetic pole 7 1 a by its reaction. However. since the action results from the inertia moment of only the armature 2 0, the kinetic energy is small and the supporting spring 7 8 is scarcely displaced downward.

Thus, since the supporting spring 7 8 is not displaced upward and is hardly displaced downward. the displacement other than a twisting of the supporting spring 7 8 can be minirni ed, whereby it is possible to reduce the bouncing, and at the same time the durability (life) of the supporting spring 7 8 can be increased.

Furthexmore, even though the projecting portion. 3 6 formed on the upper surface of the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b and the concave portion 3 5 formed at the armature 2 0 are inversely formed, it is also possible to obtain a effect simila thereto.

Furthermore. although the projecting portion 3 6 is circular column- Eke in the sixth preferred embodiment of the invention, it is needless to say that the shape of the projecting portion 3 6 is not limited to the above.

Still furthermore. as described in the fourth preferred embodiment of the invention. since it is possible to absorb the impact vibrations of the armature 2 0 by causing a plastic sheet to intervene between the armature 2 0 and the magnetic pole 7 1, it possible to reduce the 48 bouncing, and the durability (fife) of the supporting spnng 7 8 can be increased.

Fig. 2 5 through Fig. 2 9 show a seventh preferred embodiment of the invention.

Herein, in a case where the spring force of the movable contact spring 7 6 is strengthened to increase the contacting pressure between the movable contact 7 7 and fixed contact 5 5 in the fifth preferred embodiment of the invention, it is considered that the insulative supporting member 21 a is pushed upward by the reaction of the movable contact spring 7 6 as shown in Fig. 2 3 (b), and the engagement of the engaging piece 3 3 a which constitutes the one- way linking means 3 2 a may be lost. (At this time, the armature 1 9 is attracted to the magnetic pole 7 1 b with the engaging piece 3 3 b made a fulcrum).

The seventh preferred embodiment of the invention is constructed so as to obtain a stabilized contacting pressure even in such situations.

An electromagnetic relay according to the seventh preferred embodiment of the invention comprises: an electroinagnet block 6 2, equipped with magnetic poles 7 1, 7 1 at both the ends thereof, comprising of an iron core 6 4 on which a coil 6 9 is wound, and a permanent magnet 7 2; an armature block 18 a comprising of an armature 19, a movable contact spring 7 6. to both the ends of which a movable contact 7 7 made of bulky precious metal tip is electrically welded, an insulative supporting member 21 a. a supporting spring 7 8 extending from the center of the movable contact spring 7 6 in the direction orthogonal thereto and fixed to the housing 5 1; a housing 5 1 equipped with a common terminal 5 8, a fixed contact terminal 5 6 to which a fixed contact 5 5 made of bulky precious tip is electrically connected by electrical welding, and a coil terminal 6 0, in which the electromagnet block 6 2 and armature block 18 a are provided; and a casing (not illustrated) external fitted to the housing 5 1, wherein the movable contact spring 7 6, supporting spring 7 8. armature 19, magnetic pole 7 1 and permanent magnet 7 2 are laminated in order from the bottom of the housing 5 1, an one-way linking means 3 2 a is composed of an engaging portion formed at the insulative supporting member 2 1 a and a portion to be engaged, which is formed at the armature 19, and the movable contact spring 7 6 and armature 19 are divided so as to cause them operate independently via the insulative supporting member 21 a.

* Fig. 2 8 is a cross- sectional view of major parts showing a first contacting pressure stabilizing mechanism. An insulative supporting member 2 1 a made of insulative material such as synthetic resin, etc., the cross- section of which is roughly channel- shaped, is insert- molded together with the movable contact spring 7 6 at the center of the movable contact spring 7 6. An engaging piece 3 3 is formed on the upper surface of the side walls 2 1 c, 2 1 d of the insulative supporting member 2 1 a.

An armature 19 made of a soft magnetic material such as an electromagnetic soft iron, etc., and formed to be roughly plate- like is disposed upward of the movable contact spring 7 6, and an opening 3 7 into which the side walls, 2 1 c, 2 1 d formed at the insulative supporting member 2 1 a are inserted is formed at the armature 19. Ile side walls 2 1 c, 2 1 d of the insulative supporting member 2 1 a and the en g piece 3 3 are inserted into and engaged with the opening 3 7. whereby the movable contact spring 7 6 is separated from the armature 19.

The. magnetic pole 7 1 of the electromagnet block 6 2 and permanent magnet 7 2 are disposed upward of the armature 19. The permanent magnet 7 2 is roughly plate- like, and both the ends thereof are magnetized to be in the same polarity with the center portion thereof magnetized to be in the different polarity. The permanent magnet 7 2 is caused to intervene between the magnetic poles 7 1, 7 1 which are the ends of the iron core 6 4.

The one-way linking means 3 2 a is constituted by the side walls 2 1 c. 2 1 d formed at the insulative supporting member 2 1 a, the cross section of which is roughly channel- shaped as shown above. passing through the opening 3 7 formed at the armature 19 and the engaging piece 3 3 which is the engaging portion provided at the end art of the side walls 2 1 c, 2 1 d being engaged with the opening 3 7 which is the portion to be engaged of the armature 19.

The first contacting pressure stabilizing mechanism is constituted by causing a magnetic flux condensing member 2 7 a to protrude roughly at the center of the armature 19 so as to confront the permanent magnet 7 2.

The actions of the magnetic flux condensing member 2 7 a are described in detail with reference to Fig. 2 9.

The magnetic flux condensing member 2 7 a is to condense the magnetic flux passing through the center of the armature 19 and the permanent magnet 7 2. Since the magnetic flux passes through a narrow path to be condensed by the magnetic flux condensing member 2 7 a, the magnetic attraction force which operates between the center portion of the armature 19 and the permanent magnet 7 2 is made greater in comparison with a case where no magnetic flux condensing member 2 7 a exists.

(a) shows a state where neither of the movable contacts 7 7 a. 7 7 b are in contact with the fixed terminals 5 5 a, 5 5 b (not illustrated). In this state, the movable contact spring 7 6 is free from any deflection, and the forces acting on the armature 19 are only a force due to a magnetic flux passing through the center portion of the armature 19 and the permanent magnet 7 2, a force due to the magnetic flux passing through the magnet pole 7 1 a and armature 19 a, and a force due to the magnetic flux passing through the magnet pole 7 1 b and armature 19 b. The engaging pieces 3 3 a, 3 3 b which constitute the one-way linking means 3 2 a are engaged with the armature 19 whereby the one- way hnldng means 3 2 a does not come off.

(b) shows a standstill state where the armature 19 a is magnetically attracted by the magnetic pole 7 1 a and the movable contact 7 7 a is brought into contact with the fixed contact 5 5 a. However, the force due to the magnetic flux passing through the center portion of the armature 19 and the permanent flux 7 2 is strengthened by the actions of the magnetic flux condensing member 2 7 a, that is, since the center portion of the armature 1 9 is attracted by the center portion of the permanent magnet 7 2. the engagement of the one- way linking means 3 2 a, 3 2 a is strengthened, whereby the one- way linIdng means 3 2 a, 3 2 a does not slip off from its engagement even by the force due to deflections of the contact spring 7 6.

Therefore, since the one-way finidng means 3 2 a does not slip off from the engagement thereof even by the deflection of the movable contact spring 7 6 which is produced when the movable contact 7 7 is brought into contact with the fixed contact 5 5, it is possible to obtain an predetermined deflection of the movable contact spring 7 6. Therefore, the contacting pressure between the movable contact 7 7 and fixed contact 5 5 is more stabilized, and the contact resistance can be more stabilized.

Furthermore, in the seventh preferred embodiment of the invention. although the magnetic flux member 2 7 a is formed of the same material as that of the armature 19. the material is not limited to this so long as it is a soft magnetic material, the saturation magnetic flux density of which is high and the magnetic permeability of which is large. The shape thereof is not limited to the above.

Fig. 30 is a cross-sectional view of major parts showing a second contacting pressure stabilizing mechanism, wherein a magnetic flux condensing member 2 7 b is provided to protrude at the center portion of the permanent magnet 7 2 so as to confront the armature 19.

In an eighth preferred embodiment of the invention, where the second contacting pressure stabilizing mechanism is employed instead of the first contacting pressure stabilizing mechanism, it is possible to obtain the same efiect as that of the seventh preferred embodiment of the invention.

Furthermore, in the eighth preferred embodiment, although the magnetic flux condensing member 2 7 b is made of the same material as that of the permanent magnet 7 2. it is not limited to the above, and it may be any other hard magnetic material. or soft magnetic material, the saturation magnetic flux density of which is high and the magnetic permeability of which is large.

Fig. 3 1 is a cross- sectional view of major parts showing a third contacting pressure stabilizing mechanism which is such that an engaging member 30a made of an elastic member, for example, rubber is caused to intervene between the armature 19 and insulative supporting member 2 1 a.

The actions of a ninth preferred embodiment of the invention III which an engaging member 3 0 a of the third contacting pressure stabilizing mechanism is employed is described. using Fig. 3 2.

(a) shows a state where both the movable contacts 7 7 a. 7 7 b are not in contact with the fixed contacts 5 5 a. 5 5 b (not illustrated). In this state, the movable contact spring 7 6 is free from any deflection. Therefore, the forces acting on the armature 19 are only a force due to a magnetic flux passing through the center portion of the armature 19 and the permanent magnet 7 2, a force due to the magnetic flux passing through the magnet pole 7 1 a and armature 19 a, and a force due to the magnetic flux passing through the magnet pole 7 1 b and armature 19 b. The engaging pieces 3 3 a, 3 3 b which constitute the one- way linIdng means 3 2 a are engaged with the armature 19, whereby the one- way hnldng means 3 2 a does not come off.

(b) shows a standstill state where the armature 19 a is magnetically attracted to the magnetic pole 7 1 a and the movable contact 7 7 a is brought into contact with the fixed contact 5 5 a. However, although the movable contact 7 7 is brought into contact with the fixed contact 5 5, deflection is generated at the movable contact spring 7 6. and a compression force is given to the engaging member 3 0 a, the distance between the armature 19 and the insulative supporting member 2 1 a is kept constant by a restoration force of the engaging member 3 0 a which is an elastic member, that is, since the engagement of the one-way linking means 3 2 a is strengthened, the one-way linking means 3 2 a does not slip off from the engagement thered Therefore, since t he movable contact spring 7 6 can obtain an predetermined deflection, the contacting pressure between the movable contact 7 7 and the fixed contact 5 5 is more stabilized as in the seventh and eighth preferred embodiments of the invention, whereby the contacting resistance is more stabilized.

Fig. 3 3 is a cross- sectional view of major parts showing a fourth contacting pressure stabilizing mechanism, wherein an engaging member 3 0 b made of an elastic member, for example, a coil spring is caused tointervene between the armature 19 and the insulative supporting member 2 1 a.

With a tenth preferred embodiment of the invention in which the fourth contacting pressure stabilizing mechanism is employed instead of the third contacting pressure stabilizing mechanism, it is possible to obtain the effect identical to that which is obtained by an electromagnetic relay according to the ninth preferred embodiment of the invention.

Furthermore, the material and shape of an engaging member 3 0 a which is the third contacting pressure stabilizing mechanism and an engaging member 3 0 b which is the fourth contacting pressure stabilizing mechanism are not limited to the above.

Fig. 3 4 through Fig. 3 7 show an eleventh preferred embodiment of the invention. A movable contact spring 7 6, supporting spring 7 8, magnetic pole 7 1, permanent magnet 17. and armature 2 0 are laminated in order from the bottom of the housing 5 1. Ilie eleventh preferred embodiment is such that a one- way linking means 3 2 b is employed. which is constituted by the engaging portion provided on the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b passing through the openings 3 7 b. 3 7 b of the permanent magnet 17 and being engaged with the portion to be engaged, which is provided at the armature 2 0. so that the movable contact spring 7 6 and armature 2 0 are separated and operate on independently. In the sixth preferred embodiment described above, in a case where it is attempted that the spring force of the movable contact spring 7 6 is strengthened in order to increase the contacting pressure between the movable contact 7 7 and fixed contact 5 5, the insulative supporting member 2 1 b is pushed upward by a repulsion force of the movable contact spring 7 6 as shown 56 - in Fig. 4 (b), whereby it is considered that the engaging concave portion 3 5 a which constitutes the one- way linking means 3 2 b is disengaged from the engaging projecting portion 3 6 a. (At this time, the armature 2 0 is attracted to the magnetic pole 7 1 b with the engaging projecting portion 3 6 b made a fulcrum).

Even in this state, with the eleventh preferred embodiment of the invention, it is possible to obtain a stabilized contacting pressure.

Fig. 3 7 is a cross- sectional view of major parts showing a ffffi contacting pressure stabilizing mechanism which is employed in the eleventh preferred embodiment of the invention, wherem an insulative supporting member 2 1 b made of insulative material such as synthetic resin, etc., and formed to be roughly channel- shaped is insert- molded at the center portion of the movable contact spnng 7 6 together with the movable contact spring 7 6, and a circular column- like projecting portion 3 6 is formed on the upper surface of the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b, the cross- section of which is roughly channel- shaped.

A magnet pole 7 1 of the electromagnet block 15 and the permanent block 17 are disposed upward of the movable contact spring 7 6, and an opening 3 7 b into which the projecting portion 3 6 formed on the upper surface of the side walls 2 1 e, 2 1 f of the channel- shaped insulative supporting member 2 1 b is inserted is formed at the permanent magnet 17.

An armature 2 0 made of a soft magnetic material such as electromagnetic soft iron, etc. and formed to be roughly plate- like is disposed upward of the magnetic pole 7 1 and permanent magnet 17, a concave portion 3 5 which is engaged with the projecting portion 3 6 formed on the upper surface of the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b is formed at the underside of the armature 2 0.

The one- way linking means 3 2 b is constituted by a projecting portion 3 6 of the engaging portion formed on the upper surface of the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b and a concave portion 3 5 of the portion to be engaged, which is formed on the armature 2 0.

The fifth contacting pressure stabilizing mechanism is such that a magnetic flux condensing member 2 7 c is provided to protrude at the center portion of the armature 2 0 so as to confront the permanent magnet 17.

With the eleventh preferred embodiment of the invention thus constructed. it is possible to obtain the same effect as that in the seventh preferred embodiment of the invention.

Fig. 3 8 is a cross- sectional view of major parts showing a sixth contacting pressure stabilizing mechanism, wherein a magnetic flux condensing member 2 7 d is provided to protrude at the center portion of the permanent magnet 17 so as to confront the armature 2 0.

In the twelfth preferred embodiment in which the sixth contacting pressure stabilizing mechanism is employed instead of the fifth contacting pressure stabilizing mechanism, it is possible to obtain the same effect as that in the eleventh preferred embodiment of the invention.

Fig. 3 9 is a cross- sectional view of major parts showing a seventh contacting pressure stabilizing mechanism. wherein the seventh contacting pressure stabilizing mechanism is such that an engaging member 3 0 c made of elastic material such as rubber is provided between the armature 2 0 and the bottom of the insulative supporting member 2 1 b.

In the thirteenth preferred embodiment m which the seventh contacting pressure stabilizing mechanism is employed. it is possible to obtain the same effect as that in the ninth preferred embodiment of the invention.

Fig. 4 0 is a cross- sectional view of major parts showing an eighth contacting pressure stabilizing mechanism. wherein the same is such that an engaging member 3 0 d made of elastic member such as a coil spring intervenes between the armature 2 0 and the insulative supporting member 2 1 b bottom.

In the fourteenth preferred embodiment m which the e ighth contacting pressure stabilizing mechanism is employed instead of the seventh contacting pressure stabilizing mechanism, it is possible to obtain the same effect as that in the thirteenth preferred embodiment of the invention.

Fig. 41 through Fig. 43 are views showing a fifteenth preferred embodiment of the invention. An electromagnetic relay according to the fifteenth preferred embodiment of the invention comprises: an electromagnet block 6 2 comprising of an iron core 6 4 on which a coil 6 9 is wound and which is provided with magnetic poles 71, 71 at both the ends thereof, and a permanent magnet 7 2; an armature block 18 a comprising of an armature 19, a movable contact spring 7 6, to both the ends of which a movable contact 7 7 made - of bulky precious metal tip is attached by electrical welding, an insulative supporting member 2 1 a, and a supporting spring 7 8 extending from the center of the movable contact spring 7 6 in the direction orthogonal thereto and fixed to the housing 5 1; a housing 5 1 equipped with a common terminal 5 8, a fixed contact terminal 5 6 to which a fixed contact 5 5 made of bulky precious metal tip is electrically connected by electrical welding, and a coil terminal 6 0 and to which the electromagnet block 6 2 and armature block 18 a are attached; and a casing (not illustrated) to which externally attached to the- housing 5 1, and the same is constructed so that the movable contact spring 7 6, supporting spring 7 8, armature 19, magnetic pole 7 1 and permanent magnet 7 2 are laminated in order from the housing 5 1 bottom, a one-way linking means 3 2 a is constructed by an engaging portion formed at the insulative supporting member 2 1 a and the portion to be engaged, which is formed at the armature 19, and the movable contact spring 7 6 and the armature 19 are separated from each other so as to independently operate via the insulative supporting member 2 1 a.

An insulative supporting member 2 1 a made of insulative material such as synthetic resin, etc., and formed to be roughly channel- shaped is insertmolded at the center of the movable contact spring 7 6 along with the movable contact spring 7 6. An engaging piece 3 3 is formed at the side walls 2 1 c, 2 1 d which are free ends of the insulative supporting member 2 1 a.

An armature 19 made of a soft magnetic material such as electromagnetic soft iron and formed to be roughly plate-like is disposed upward of the movable contact spring 7 6, and an opening 3 7 into which side walls 2 1 c, 2 1 d formed at the insulative supporting member 2 1 a are inserted is formed at the armature 19, wherein the side walls 2 1 c, 2 1 d of the insulative supporting body 2 1 a and the engagmg piece 3 3 are inserted into and engaged with the opening 3 7, thereby causing the movable contact spring 7 6 and armature to be separated.

The magnetic pole 7 1 of the electromagnet block 6 2 and permanent magnet 7 2 are disposed upward of the armature 19. The.permanent magnet 7 2 is formed to be roughly plate- like, wherein both the ends thereof are magnetized to be the same polarity and the central portion thereof is magnetized to be the other polarity. And the permanent magnet 7 2 is provided to intervene between the magnetic poles 7 1, 7 1 which are at the ends of the iron core 6 4.

The one-way linking means 3 2 a is constituted so that the side walls 2 1 c, 2 1 d formed at the insulative supporting member 2 1 a, the crosssection of which is formed to be roughly channel- shaped as described above. is caused to pass through the opening 3 7 formed at the armature 19 and the engaging piece 3 3 which is the engaging portion provided at the ends of the side walls 2 1 c, 2 1 d is engaged with the opening 3 7 which is the portion to be engaged of the armature 19.

A contacting pressure stabilizing mechanism is such that a magnetic flux condensing member 2 7 a is provided to protrude at the center portion of the armature 19 so as to confront the permanent block 7 2.

The magnetic flux condensing member 2 7 a is to condense the magnetic flux passing through the center portion of the armature 19 and the permanent magnet 7 2. Since the magnetic flux is concentrated to pass through a narrow path by the magnetic flux condensing member 2 7 a, a magnetic attraction force operating between the center portion of the armature 19 and the permanent magnet block 7 2 is made greater in comparison with a case where no magnetic flux condensing member 2 7 a exists. Therefore, even though the movable contact 7 7 is brought into contact with the fixed contact 5 5 and deflection is produced at the movable contact spring 7 6, the one-way linking means 3 2 a does not slip off from its engagement and an predetermined deflection of the movable contact spring 7 6 can be obtained.

Therefore, the contacting pressure between the movable contact 7 7 and fixed contact 5 5 is stabilized, and the contacting resistance is also stabilized.

In the fifteen preferred embodiment of the invention, by the displacement stopper 2 5 a being provided in the housing 5 1 in such a state that the same is brought into contact with the upper part of the supporting spring 7 8 or slightly apart therefrom, it is possible to regulate, by a magnetic attraction force which is produced by the magnetic flux condensing member 2 7 a, an upward displacement of the supporting spring 7 8 due to the upward displacement of the armature 19. Therefore, it is possible to increase the durability (life) of the supporting spring 7 8 and furthermore possible to obtain a more stabilized contacting pressure, whereby it is possible to finther prevent bouncing of the contacts.

Fig. 4 4 through Fig. 4 6 show a sixteenth preferred embodiment of the invention, wherein a movable contact spring 7 6, supporting spring 7 8, magnetic pole 7 1, permanent magnet 17 and armature 2 0 are laminated in order from the bottom of the housing 5 1, the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b pass through the openings 3 7 b, 3 7 b of the permanent magnet by the engaging portion formed at the end of the insulative supporting member 2 1 b and the portion to be engaged of the arm 2 0, whereby the one- way linking means 3 2 b is constructed, the movable contact spring 7 6 and armature 2 0 are separated so as to independently operate.

An insulative supporting member 21 b made of an insulative material such as synthetic resin. the cross-section of which is roughly channel-shaped, is insert-molded at the center portion of the movable contact spring 76 along with the movable contact spring 76, and a circular column- Eke projecting portion 3 6 is formed on the upper surface of the side walls 2 1 e, 2 1 f which are free ends of the insulative supporting member 2 1 b, the cross-section of which is channel-shaped.

The magnetic pole 7 1 of the electromagnet block 15 and permanent magnet 17 are disposed upward of the movable contact spring 7 6, and an opening 3 7 b into which a projecting portion 3 6 formed on the upper surface of the side walls 2 1 e, 2 1 f of the channel- shaped insulative supporting member 2 1 b is formed on the permanent magnet 17.

An armature 2 0 made of a soft magnet material such as electromagnetic soft iron and formed to be roughly channel- shaped is disposed upward of the magnetic pole 7 1 and permanent magnet 17, and a concave portion 3 5 which is engaged with the projecting portion 3 6 formed on the upper surface of the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b is formed at the underside of the armature 2 0.

The one-way linldng means 3 2 b is constituted by the projecting portion 3 6 of the engaging portion formed on the upper surface of the side walls 2 1 e, 2 1 f of the insulative supporting member 2 1 b and the concave portion 3 5 of the portion to be engaged, which is formed on the armature 2 0.

The contacting pressure stabilizing mechanism is such that a magnetic flux condensing member 2 7 c is provided to protrude at the center portion of the armature 2 0 so as to confront the permanent magnet 17.

In the sixteenth preferred embodiment of the invention, by the displacement stopper 2 5 b being provided in the housing 5 1 In such a state that the same is brought into contact with the lower part of the supporting spring 7 8 or slightly apart therefrom, it is ossible to regulate, by a magnetic attraction force which is produced by the magnetic flux condensing member 2 7 c, a downward displacement of the supporting spring 7 8 due to the downward displacement of the armature 2 0. Furthermore, it is possible to increase the durability (life) of the supporting spring 7 8, and at the same time possible to obtain a more stabilized contacting pressure, whereby it is possible to prevent bouncing of the contacts.

Fig. 4 7 through Fig. 4 9 are views showing a seventeenth preferred embodiment of the invention, wherein 1 is a housing which is provided with an insulative substrate 2 made of ceramic or glass- coated metal, etc., and the respective terminals such as a fixed contact terminal 5 formed by press-working a copper alloy thin plate, a common terminal 8, a coil terminal 11 etc, and has a fixed contact 4 made of sinter- molded metal thick film paste of precious metal.

Hereupon, a conventional housing 51 is provided with the respective terminals such as a fixed contact terminal 5 6, common terminal 5 8, coil terminal 6 0, etc. and a fixed contact 5 5, and the respective terminals such as a fixed contact terminal 5 6, common terminal 5 8. coil terminal 6 0, etc. which are formed to an predetermined shape by press- working a copper alloy conductive thin plate are insert- molded so that one end thereof can protrude from the underside of the housing 5 1 (See Fig. 6 9 and the followings of the conventional example).

However, there was such a problem that since the shape of each of the terminals such as the fixed contact terminal 5 6 is complicated, the metal dies for insert- molding are made complicated, which causes the production cost to be increased.

Furthermore, since in the housing 5 1 the fixed contact terminal 5 6, etc. are insert- molded with synthetic resin. etc., the thermal conductivity thereof is poor. ff electric current is caused to flow to the coil 6 9, a temperature difference is generated at the respective terminals 5 6, 5 8, 6 0, - fixed contact 5 5, the respective terminal junction parts 5 7, 5 9, 6 1, etc. whereby a thermoelectromotive force is produced between the fixed contact terminal 5 6 and common terminal 5 8. If they are used for small capacity circuits, the thermoelectromotive force results in a problem.

Furthermore. heat is generated by the contacting resistance of the contacts and electric charge, depending upon the current and voltage conditions under which they are used, and the heat is not dissipated due to poor thermal conductivity thereof, thereby resulting in fusion and weld of the. contacts and finally a shortening. the durability (fife) of the contacts.

Still furthermore, since the fixed contact terminals 5 6 and common terminals 5 8 which are signal lines are insert- molded, the high frequency characteristics thereof are insufficient- Therefore, for high frequency communication such as mobile communication, digital communication, etc. it is desired that an electromagnetic relay having superior high frequency characteristics be developed.

- In addition, since the fixed contacts 55 are formed by electrically welding a bulky precious metal tip to the fixed contact junction parts 5 7, unevenness of the fixed contacts 5 5 frequently results from a poor state of electric welding or insert- molding, and complicatedness of the terminal shape, whereby the distance between the fixed contacts 5 5 and the movable contacts 7 7 is always different at every contact, resulting in unevenness of the contacting pressure of the respective contacts, whereby the bouncing is promoted, and at the same time the operation timing is imbalanced. Finally, - 66 the reliability of the electromagnetic relay is worsened. This frequently occurs especially in multi-contact electromagnetic relay.

Furthermore, if the welding is insufficient, the thermal resistance between the fixed contact 5 5 and fixed contact junction part 5 7 is made large, and especially, if they are used in a state where an arch discharge occurs, the wearing of the contacts is severe, thereby causing the durability (life) of the contacts to be shortened.

The seventeenth preferred embodiment of the invention is provided with a one-way linking means 32a which is constituted so that the movable contact spring 7 6, supporting spring 7 8 a, armature 19, magnetic pole 7 1 and permanent magnet 7 2 are laminated in order from the bottom of the housing 1, wherein the movable contact spring 7 6 and armature 19 are separated by the engaging portion provided at the insulative supporting member 2 1 a and the portion to be engaged, which is provided at the armature 19, so as to independently operate.

Fig. 5 0 through Fig. 5 2 are views showing a housing I of the seventeenth preferred embodiment of the invention, wherein a fixed contact terminal junction part 6, common terminal junction part 9. coil terminal junction part 12, etc. which are sinter- molded with metal thick film paste of copper alloy, etc. are formed at the underside of the insulative substrate 2, and as necessary the respective lead portions of a common terminal lead part 10, coil terminal lead portion 13, etc., are sinter- molded with metal thick film paste of copper alloy, whereby each of them is electrically connected to the fixed terminal junction part 6, common terminal junction part 9, and coil terminal junction part 12.

A fixed contact lead portion 7 is sinter- molded with metal thick film paste of copper alloy on the upper surface of the insulative subtrate 2.

A plurality of through holes 3 are formed at an predetermined place of the insulative subtrate 2, into which the fixed contact terminal 5, common terminal 8, coil terininal 11, etc. are inserted from the underside of the insulative substrate 2 and fixed therein. The respective terminals 5, 8, 11 are electrically connected to the respective junction parts 6. 9, 12 formed at the underside of the insulative substrate 2 by soldering. Furthermore, the fixed contact lead portion 7 and fixed contact terminal junction part 6 are able to be electrically connected to each other by promptly using an already known method, wherein for example, metal thick film paste is sinter-molded inside the through holes 3.

Furthermore, it is possible to form the fixed contact terminal lead portion 7, common terminal lead portion 10, coil terminal lead portion 13 and the respective junction parts 6. 9. 12 on either surface of of the insulative substrate 2 by utilizing these through holes 3. Still furthermore, it is also acceptable to form notches at the end portions of the insulative substrate instead of through holes 3.

The fixed terminal 4 is formed on the upper part of the fixed contact junction part 6 through printing and sintering a thick fihn paste in which predetermined kinds of metal are mixed, by an already known screen 68 printing method. Therefore, it is possible to easily adjust the height of contacts by only controlling the thickness of the thick film paste to be printed.

Furthermore, since the respective junction parts 6, 9. 12, and each of fixed contact lead portion 7, common terminal lead portion 10, cog terminal lead portion 13. etc., are able to be formed as well as the fixed contact 4, no unevenness is generated for the height of the fixed contact 4, differing from the fixed contact 5 5 in which a bulky precious metal tip made of clad material is fixed and formed on the upper surface of the fixed contact terminal 5 6 integrated with the base 5 2 like a conventional electromagnetic'relay.

Fig. 5 3 and Fig. 5 4 are views which explain an armature block 18 c according to the seventeenth preferred embodiment of the invention. The armature block 18 c consists of a movable contact spring 7 6. insulative supporting member 2 1 a. and a supporting spring 7 8 extending from the center portion of the movable contact spring 7 6 in the direction orthogonal thereto. However, an insulative supporting member 21 a made of insulative material such as synthetic resin, etc. the cross- section of which is roughly channel- shaped is insert- molded along with the movable contact spring 7 6 at the center portion of the movable contact spring 7 6, and an engaging piece 3 3 is formed on the upper surface of the side walls 2 1 c, 2 1 d of the - insulative supporting member 2 1 a.

Furthermore, the supporting spring 7 8 which is mechanically and electrically integral with the movable contact spring 7 6 is formed so as to extend from the lengthwise center of the movable contact spring 7 8 in the 69 - direction orthogonal thereto, and further the tip end thereof is bent roughly at a right angle and is inserted into an predetermined through hole 3 provided at the insulative -substrate 2 of the housing 1, wherein the same is soldered to the common terminal junction part 6 to ensure an electrical connection with the common terminal 8.

$ince the supporting spring 7 8 a is directly soldered to the common terminal junction part 6, the reliability thereof is further increased.

An armature 19 made of soft magnetic material such as electromagnetic soft iron, etc. and formed to be roughly channel- shaped is disposed upward of the movable contact spring 7 6, an opening 3 7 into which the side walls 2 1 c, 2 1 d formed at the insulative supporting member 2 1 a are inserted is formed at the armature 19, and the side walls 2 1 c, 2 1 d of the insulative supporting member 2 1 a are inserted into and engaged with the opening 3 7 together with the engaging piece 3 3. whereby a one- way linking means 3 2 a is constituted.

Furthermore, if a block frame 3 8 is provided for the armature block 18 c shown in Fig. 5 5 and Fig. 5 6, the fixing property thereof with the insulative substrate 2 is much enhanced, thereby causing the reliability thereof to be much increased.

In the seventeenth preferred embodiment of the invention. it is possible to reduce the generation of bouncing and simultaneously to increase the durability (life) of the supporting spring 7 8 a.

In addition, as already explained in the fourth preferred - embodiment of the invention, since it is possible to absorb impact vibrations of the armature 19 by causing a plastic sheet to intervene between the armature and magnetic pole, it is possible to reduce the generation of bouncing and to fin-ther increase the durability (life) of the supporting spring 7 8 a.

Furthermore, in the seventeenth preferred embodiment of the invention, a one-way linking means 3 2 a is employed as an armature block, and the movable contact spring 7 6. supporting spring 7 8 a, armature 19, magnetic pole 7 1 and permanent magnet 7 2 are laminated in order from the bottom of the housing 1. However, the arrangement thereof is not limited to this. It is needless to say that with a one-way finidng means 3 2 b employed. the movable contact spring 7 6, supporting spring 7 8 a, magnet pole 7 1, permanent magnet 17 and armature 2 0 may be laininated in order from the bottom of the housing I Furthermore, even in the armature block in which the armature 75 and movable contact spring 76 are made integral with each other by the insulative supporting member 7 9. it is also possible to obtain the similar effect by providing the same with a stopper which regulates upward or downward displacement of the supporting spring in line with the displacement of the armature.

In the seventeenth preferred embodiment of the invention, the temperature distribution is made small in the insulative substrate 2 since the thermal conductivity is superior due to use of an insulative substrate made of ceramic, etc. whereby the thermoelectromotive force between the fixed contact terminal 5 and common terminal 8 is made small, the insulative 71 substrate 2 becomes optimal for small signal monitoring, and the signal noise is minimized. Therefore, it is possible to provide a higher performance electromagnetic relay.

Furthermore, since the fixed contact 4 and fixed contact lead portion 7 are sinter-molded with a metal thick film paste in addition to superior thermal conductivity due to use of the insulative substrate 2, the thermal resistance between the fixed contact 4 and fixed contact lead portion 7 is made small, whereby even though the same is used under the conditions of generating an arc discharge, the contact Iffe can be lengthened.

Still furthermore, since a thick film paste with which predetermined kinds of metal are mixed is printed to an predetermined pattern and sintered to form a substrate, it is easy to adjust the height of fixed contacts, whereby the mass production efficiency there of is much increased with the unevenness of the contact height minimized, and the terminal array is made easier.

Especially, in an electromagnetic relay having a number of contacts, the contacting pressure between the respective contacts is stabilized to cause the operation timing to be synchronized. Therefore, generally, the reliability of electromagnetic relays will be much increased.

In addition, by using a ceramic substrate, it is easy to form a microstrip line path and coplana line path. whereby fixed contact lead portions 7 and common terminal lead portions 10 are formed of a microstrip line path and coplanar line path, and it is possible to constitute an electromagnetic relay - 72 of superior high frequency characteristics.

An eighteenth preferred embodiment (not illustrated) of the invention is such that a movable contact (for example, reference number 7 7 in Fig. 5 4) is formed by sinter- molding thick film metal of a precious metal, etc. in addition to the seventeenth preferred embodiment of the invention.

A movable contact is formed through printing and sinter- molding of a thick film paste with which an predetermined kind of metal is mixed, by an already known screen printing method, at both the ends of the movable contact spring 7 6. Therefore, the thermal resistance between the movable contact 7 7 and movable contact spring 7 6 is made lower, and it is possible to lengthen the contact durability (life) even though the same isused in the conditions of generating an arc discharge.

Still furthermore, since it is possible to form a thick film paste with which an predetermined kind of metal is mixed, through printing and sinter- molding the same to an predetermined pattern by an already known screen printing method. it is easy to adjust the contact height, and the mass production efficiency can be much increased with the unevenness of the accuracy minimi ed.

Especially, in an electromagnetic relay having a number of contacts, the contacting pressure between the respective contacts is stabilized, and the operation timing is synchronized, whereby the reliability of electromagnetic relays can be much increased.

Fig. 5 7 through Fig. 5 9 show a nineteenth preferred - 73 embodiment of the invention, wherein 1 is a housing which is provided with an insulative substrate 2 made of ceramic or glass-coated metal, etc. , and the respective terminals of a fixed contact terminal 5 formed by press-working a copper alloy thin plate, etc., a common terminal 8, a coil terminal 11, etc., and is further equipped with a fix contact 4 made of sinter-molded metal thick film paste of a precious metal, etc. Still furthermore, the same is provided with a one-way linking means 3 2 a constructed so that the movable contact spring 7 6, supporting spring 7 8 a, armature 19, magnetic pole 7 1 permanent magnet 7 2 are laminated in order from the bottom of the housing I and the movable contact spnng 7 6 and armature 19 are separated and designed to independently operate by the engaging portion provided at the insulative supporting member 21 a and the portion to be engaged, which is provided at the armature 19, wherein a contacting pressure stabilizing mechanism, in which a magnetic flux condensing member 2 7 a is provided to protrude at the center portion of the armature 19 so as to confront the permanent magnet 7 2 is employed.

In the nineteenth preferred embodiment of the invention, which is thus constructed, it is possible to obtain an effect simila to that of the eighteenth preferred embodiment, and at the same time it is also possible to obtain an effect similar to that of the seventh preferred embodiment.

Furthermore, the contacting pressure stabilizing mechanism is not limited to a magnetic flux condensing member 2 7 a.

Fig. 6 0 through Fig. 6 2 show a twentieth preferred - 74 embodiment of the invention, wherein I is a housing which is provided with an insulative substrate 2 made of ceramic or glass-coated metal, etc. , groups of fixed contact terminals 5 formed by press-working copper alloy thin plate, etc., common terminals 8, coil terminals 11, etc., and is further equipped with a fixed contact 4 made of sinter- molded metal thick film paste of precious metal, etc., wherein a contacting pressure stabilizing mechanism in which a magnetic flux condensing member 2 7 c is provided to protrude at the center portion of the armature 2 0 so as to confront the permanent magnet 17 is employed.

In the twentieth preferred embodiment of the invention as constructed above, it is possible to obtain an effect simila to that of the nineteenth preferred embodiment of the invention.

Fig. 6 3 through Fig. 6 5 show a twenty- first preferred embodiment of the invention, in which a displacement stopper 2 5 c is provided at the block frame 3 8 in such a state that the same is in contact with or slightly apart from the upper part of the supporting spring 7 8 a. in addition to the nineteenth preferred embodiment of the invention.

In the twenty- first preferred embodiment of the invention as constructed above, since it is possible to regulate, by a magnetic attraction force produced by the magnetic flux condensing member 2 7 a, the upward displacement of the supporting spring 7 8 a, which is produced along with the upward displacement of the armature 19, it is possible to further increase the durability (life) of the supporting spring 7 8 a, and simultaneously possible to obtain a more stabilized contacting pressure. whereby the bouncing of contacts can be finther prevented from occumng.

Fig. 6 6 through Fig. 6 8 show a twenty- second preferred embodiment of the invention, wherein in addition to the twentieth preferred embodiment of the invention. a displacement stopper 2 5 d is provided at the block frame 3 8 in such a state that the same is in contact with or slightly apart from the lower part of the supporting spring 7 8 a.

In the twenty- second preferred embodiment of the invention as. constructed above. since it is possible to regulate, by a magnetic attraction force produced by the magnetic flux condensing member 2 7 c, the downward displacement of the supporting spring 7 8 a, which is produced along with the downward displacement of the armature 2 0, it is possible to fin-ther increase the durability Gife) of the supporting spring 7 8 a and simultaneously to increase a more stabilized contacting pressure. whereby the bouncing of contacts can be prevented from occurring.

- 76 WHAT IS CLAWED IS:

I An electromagnetic relay comprising: an electromagnet block comprising of an iron core on which a coil is wound, and a permanent magnet; an armature block comprising of an armature, a movable contact spring, an insulative supporting member, and a supporting spring extending from a center of the movable contact spring in a direction perpendicular thereto and fixed to a housing, in which the armature and movable contact spring are made integral with each other by the insulative supporting member, which can inversely rock between a pair of magnets centering around the supporting spring; the housing having a common terminal, and fixed contact terminal and coil terminal, and to which the electromagnet block is attached; and a casing outwardly fitted to the housi being characterized by further comprising a stopper which regulates an upward or downward displacement of the supporting spring, which displacement is generated by rocking of the armature.

2. An electromagnetic relay as set forth in claim 1, wherein the stopper which regulates the upward or downward displacement of the supporting spring is provided at the housing in such a state that the stopper is in contact with or slightly apart from an upper or lower part of the supporting spring.

3. An electromagnetic relay as set forth in claim 1, wherein the stopper which regulates the upward or downward displacement of the supporting spring is provided on an underside of the permanent magnet or an upper surface of a housing bottom in such a state that the stopper is in contact with or slightly apart from an underside or an upper surface of the insulative supporting member of the armature block.

4. An electromagnetic relay as set forth in claim 1 wherein the stopper which regulates the upward or downward displacement of the supporting spring is provided on the upper surface or underside of the insulative supporting"member of the armature block in such a state that the stopper is in contact with or slightly apart from the underside of the permanent magnet or the upper surface of the housing bottom.

5. An electromagnetic relay comprising: an electromagnet block comprising of an iron core on which a coil is wound, and a permanent magnet; an armature block comprising of an armature, a movable contact spring, an insulative supporting member, and a supporting spring extending from a center of the movable contact spnng in a direction perpendicular thereto and fixed to a housing-, the housing being provided with a common terminaL a fixed contact terminal and a coil terminal, to which the electromagnet block and armature block are attached; being characterized in that the armature and insulative supporting member are independently constituted, the armature block is provided with a - 78 one-way linking means which can transmit the displacement of the armature in one direction, and both the movable contact spring and armature are caused to inversely rock between a pair of magnetic poles by excitation of the coil, centering around the supporting spring.

6. An electromagnetic relay set forth in claim 5, wherein the one-way linking means is constructed so that the movable contact spring, supporting spring, insulative supporting member, armature, permanent magnet and magnetic poles are disposed in order from a housing bottom, the engaging portion is lifted upward by engagement of the engaging parts secured at the insulative supporting member with the parts to be engaged. which is secured at the armature, by utilizing the fact that the armature is attracted upwards or to one of the magnetic poles by a magnetic flux of the permanent magnet or a magnetic flux produced by excitation of the coil.

7. An electromagnetic relay as set forth in claim 6, wherein the one-way linking means consists of an engaging part secured at the insulative supporting member and a part to be engaged, which is secured at the armature, and the engaging part is engaged with the part to be engaged, via an opening formed at the armature or a side portion of the armature.

8. An electromagnetic relay as set forth in claim 6 or 7, wherein the oneway linking means consists of an engaging piece of the engaging parts formed at the free end of the insulative supporting member and an opening of the part to be engaged, which is secured at the armature, the engaging part of the insulative supporting member passes through the opening of the armature, and when the, armature is displaced by being attracted into any one of the magnetic poles in an predetermined direction. transmission of vibrations to the contact spring,due to collision between the armature and the magnetic pole is attenuated and lightened by the one-way linking means.

9. An electromagnetic relay as set forth in claim 5, wherein the one-way linicing means is constructed so that the movable contact spring, supporting spring, insulative supporting member, permanent magnet, magnetic poles and armature are disposed in order from a housing bottom, a engaging portion is pressed downward by engagement of the engaging parts secured at the insulative supporting member with the parts to be engaged, which is secured at the armature, by utilizing the fact that the armature is attracted down or to the magnetic pole by a magnetic flux of the permanent magnet or a magnetic flux produced by excitation of the coil.

10. An electromagnetic relay as set forth in claim 9, wherein the one-way linkin means consists of an engaging part secured at the insulative supporting member and a part to be engaged. which is secured at the armature. and the engaging part is engaged with the part to be engaged via an opening formed at the permanent magnet or a side portion thereof.

11. An electromagnetic relay as set forth m claim 9 or 10. wherein the one-way linking means consists of an engaging convex part formed at the free end of the insulative supporting member and a concave part to be engaged.

which is secured at the arm ature, the engaging convex part of the insulative supporting member passes through the opening formed at the permanent magnet, and when the armature is displacedby being attracted to any one of the magnetic poles by excitation of the coil in an predetermined direction, transmission of vibrations to the contact spring due to collision between the armature and magnetic poles is attenuated or lightened by the one-way linking means.

12. An electromagnetic relay as set forth in claim 6, wherein a contacting pressure stabilizing mechanism is provided, by which the contacting pressure between the movable contact and fixed contact is prevented from be' lowered since an predetermined deflection of the contact spring is not obtained due to a weakening or lightening of the engagement of the one-way linking means due to deflection of the contact spring which is produced when the movable contact is brought into contact with the fixed contact.

13. An electromagnetic relay as set forth in claim 9, wherein a contacting pressure stabilizing mechanism is provided, by which the contacting pressure between the movable contact and fixed contact is prevented from being lowered since an predetermined deflection of the contact spring is not obtained due to a weakening or lightening of the engagement of the one-way linking means due to deflection of the contact spring which is produced when the movable contact is brought into contact with the fixed contact.

14. An electromagnetic relay as set forth in claim 12 or 13. wherein the contacting pressure stabilizing mechanism is a magnetic flux condensing member which can condense the magnetic flux passing through almost a center of the armature and the permanent magnet.

81 - 15. An electromagnetic relay as set forth in claim 14, wherein the magnetic flux condensing member is provided almost at a center of the armature which confronts the permanent magnet.

16. An electromagnetic relay as set forth in claim 14, wherein the magnetic flux condensing member is provided almost at a center of the permanent magnet which confronts the armature.

17. An electromagnetic relay as set forth in claim 12 or 13, wherein the contacting pressure stabilizzing mechanism is an engaging piece comprising of an elastic member which intervenes between the armature and the insulative supporting member.

18. An electromagnetic relay as set forth in claim 17, wherein the engaging piece is a plate spring or a coil spring.

19. An electromagnetic relay as set forth in claim 17, wherein the engaging piece is a circular or square column- like rubber.

2 0. An electromagnetic relay as set forth in claim 14, wherein a displacement stopper which regulates an upward displacement of the supporting spring, which is produced in line with a magnetic attraction force by the magnetic flux condensing member, is provided in contact with or slightly apart from an upper part of the supporting spring, or the displacement stopper which regulates a downward displacement of the supporting spring, which is produced in line with a magnetic attraction force by the magnetic flux condensing member, is provided in contact with or slightly apart from the lower portion of the supporting spring.

82 - 2 1. An electromagnetic relay as set forth in any one of claim 1. 2, 3, 4, 5, 6, 7, 8. 9. 10, 11, 12, 13, 14, 15, 16, 17, 18. 19, or 2 0, wherein the housing is provided with an insulative substrate made of ceramic or glass- coated metal, a fixed contact made of a sinter- molded thick fihn formed on the insulative substrate, an armature block, and fixing portion at which the electromagnet block is fixed. and the insulative substrate is provided with a coil terminal, common terminal, and fixed contact terminal.

2 2. An electromagnetic relay as set forth in any one of claim 1, 2, 3. 4, 5, 6, 7, 8, 9, 10. 11, 12. 13, 14, 15. 16, 1 7. 18, 19, 2 0 or 2 1, wherein the movable contact formed at both ends of the movable contact spring is made of a sinter- molded thick film.

2 3. An electromagnetic relay as set forth in any one of claim 1, 2.

3. 4, 5, 6, 7. 8, 9. 10, 11, 12, 13, 14, 15, 16.17, 18, 19. 2 0. 2 1 or 2 2, wherein a plastic sheet is caused to intervene between the armature and magnetic pole.

24. An electromagnetic relay substantially as herein described with reference to any one of the figures 1 to 68 of the accompanying drawings.