Switch Element

Abstract

A switch element having at least one pair of contacts to be switched-on and switched-off states, where the switch-on and the switch-off are controlled in accordance with only the attractive force or the repelling force acting between magnetic poles produced on each of two magnets which form the switch element, without the use of the internal stress of the arm of each of the contacts, and in which each the switched-on state and the switched-off state of the switch element is self-held by utilizing the residual flux density in a magnetic circuit including said pair of contacts.

Description

This invention relates to switch elements which are self-held by attractive force between magnetic poles, and, more particularly, to switch elements having contacts which are switched-on or switched-off in accordance with attractive or repelling forces between magnetic poles.

Switch elements of this type, such as reed release, have been broadly used in the art as channel switches of switching systems, etc. However, contacts of the conventional switch elements of this type are usually switched-on (or switched-off) by applying magnetic attractive force (or magnetic repelling force) between a pair of magnetic poles arranged in a narrow space (or in a contacted state) so as to be opposed to the internal stress of a pair of reeds which support a pair of the magnetic poles respectively. Accordingly, the conventional switch elements have disadvantages such that the quantity of energy necessary to switch-in, switch-off or to hold the switch-in state is relatively large.

An object of this invention is to provide switch elements having contacts which are switched-on or switched-off in accordance with an attractive or repelling force between magnetic poles, while producing a small loss of control energy at a high operation speed.

In a switch element of this invention, switch-on and switch-off motions of a pair of contacts are controlled in accordance with only the attractive force or the repelling force acting between magnetic poles, without the use of the internal stress of an arm of each of the contacts. Moreover, the switched-on state or the switched-off state of the element of this invention is self-held by utilizing the residual flux density in a magnetic circuit including a pair of contacts.

The principle of this invention will be better understood from the following more detailed discussion in conjunction with the accompanying drawings, in which the same or equivalent parts are designated by the same or equivalent numerals, characters, and symbols, and in which:

FIG. 1 is a schematic view explanatory of the construction of the switch element of this invention;

FIG. 2 shows magnetic hysteresis characteristics of small magnetic plates used in the switch element of this invention;

FIG. 3 shows time charts explanatory of drive currents used in the switch element of this invention;

FIG. 4 is a schematic view explanatory of the construction of another example of the switch element of this invention;

FIG. 5 is a perspective view illustrating an example of a single-wire type switching part used in the switch element of this invention;

FIG. 6 is a perspective view illustrating an example of a double switching part of double-wire type used in the switch element of this invention;

FIGS. 7 and 8 are respectively a perspective view and a plan view illustrating another example of the switch element of this invention;

FIG. 9 is a vertical view illustrating another example of the switch element of this invention;

FIG. 10 is a connection diagram for illustrating an example of a matrix switching network formed by the use of switch elements of this invention;

FIGS. 11 and 12 are time charts explanatory of examples of drive currents used in the matrix switching network shown in FIG. 10; and

FIG. 13 is a connection diagram for illustrating another example of the switch element used in the matrix switching network shown in FIG. 10.

With reference to FIG. 1, the main parts of a representative switch element of this invention comprise a movable small magnetic plate A, a fixed magnetic plate G, a first control means (W.sub.1, W.sub.1a ) and a second control means (W.sub.2). The fixed magnetic plate G is a U-shaped magnet having two pairs of opposed magnetic poles ((Q.sub.1, Q.sub.2 ) and (Q.sub.1a , Q.sub.2a ) ). The center of the movable small magnetic plate A is rotatably supported on a supporting pin O between two pairs of opposed magnetic poles Q.sub.1, Q.sub.2, Q.sub.1a and Q.sub.2a so that each of the magnetic poles (S, N) of the movable small magnetic plate A can be contacted to both of one pair ((Q.sub.1, Q.sub.2 ) or (Q.sub.1a , Q.sub.2a ) of said two pairs of the magnetic poles of the fixed magnetic plate G. The first control means comprises two windings W.sub.1 and W.sub.1a wound on a common leg of the U-shaped, fixed magnetic plate G to magnetize the U-shaped magnet in the reverse directions respectively. The second control means comprises a winding W.sub.1 wound on a fixed bobbin BO to magnetize the movable small magnetic plate A. The fixed magnetic plate G is made by a magnetic material having a substantially rectangular hysteresis characteristic K.sub.1 as shown in FIG. 2, and the movable small magnetic plate A is made by a magnetic material having a hysteresis characteristic K.sub.2 of low residual flux density as shown in FIG. 2.

Contacts controlled between the ON-state and the OFF-state are not shown in FIG. 1 for simple illustration but will be described below. However, it is assumed at this time that the state shown in FIG. 1 of the movable small magnetic plate A is the ON-state and the reversely switched state thereof is the OFF-state.

The operation of the example shown in FIG. 1 will be described with reference to FIG. 3. If drive currents iw.sub.1 and iw.sub.2 are respectively passed through the windings W.sub.1 and W.sub.2 at a time T.sub.1 as shown in FIG. 3, the magnetic poles Q.sub.1, Q.sub.2, Q.sub.1a and Q.sub.2a are respectively magnetized to the states "S," "N," "N" AND "S" while the magnetic poles P.sub.1 (P.sub.2 ) and P.sub.1a (P.sub.2a ) of the movable small magnetic plate A are respectively magnetized to the states "S" and "N" as shown in FIG. 1. Accordingly, the movable small magnetic plate A rotates with respect to the supporting pin O so as to assume the OFF-state since two poles (Q.sub.1, P.sub.1 or Q.sub.1a , P.sub.1a ) repel each other. In this case, if the ampere-turn of the winding W.sub.1 is sufficiently large, the two plates A and G are still maintained in the OFF-state in which the magnetic poles P.sub.1 (or P.sub.3a ) and Q.sub.2 (or Q.sub.2a ) contact each other, since the fixed magnetic plate G is still magnetized as shown in FIG. 1, even when the drive current iw.sub.1 is terminated at a time T.sub.1. Thereafter, if drive currents iw.sub.2 and iw.sub.1a are respectively flowed through the windings W.sub.2 and W.sub.1 at a time T.sub.3 as shown in FIG. 3, the states of the magnetic poles of the fixed magnetic plate G are all reversed from the states shown in FIG. 1, while the states of the magnetic piles of the movable small magnetic plate A are maintained without change as shown in FIG. 1. Accordingly, magnetic poles P.sub.1 and P.sub.1a of the movable small magnetic plate A rotate so as to contact respectively to the poles Q.sub.1 and Q.sub.1a of the fixed magnetic plate G as shown in FIG. 1. This ON-state is maintained also after the termination of the drive currents iw.sub.2 and iw.sub.1a by the residual magnetic flux of the fixed magnetic plate G.

In general, the magnitude of force acting between two magnetic poles is inversely proportional to the distance squared between the two magnetic poles. Accordingly, the attractive force between poles of the two magnetic plates A and G act effectively during both ON-state and the OFF-state since the opposed poles of the two magnetic plates A and G contact each other or are extremely close to each other during such states. While the contacts of the conventional switch element of this type are moved in opposition to the internal stress of reeds or arms, the movable small magnetic plate A of the switch element of this invention is rotated with respect to the supporting pin O within a small rotation angle region by the use of only attractive force or repelling force acting between magnetic poles oppositely arranged. Accordingly, the loss of the energy in the switch element of this invention is almost negligible.

The switch element of this invention may be constructed as shown in FIG. 4. In this example, two magnetic plates A and G have, respectively, hysteresis characteristics K.sub.1 and K.sub.2 shown in FIG. 2, so that the windings W.sub.1 and W.sub.1a are wound on the movable small magnetic plate A while the winding W.sub.1 is wound on the fixed magnetic plate G. The bobbin BO in this example is arranged so as to rotate together with the movable small magnetic plate A. The movable small magnetic plate A of this example can be also controlled similarly as in the operation of the example shown in FIG. 1, by the use of the drive currents iw.sub.1, iw.sub.2 and iw.sub.1a shown in FIG. 3.

In the above example, it is assumed that the movable small magnetic plate A or the fixed magnetic plate G is entirely made of ferromagnetic material having a rectangular hysteresis characteristic. However, only a part of either the plate A or G may be made by ferromagnetic material having a rectangular hysteresis characteristic as shown by a reference Ga in FIG. 1 by way of example. In this case, the remaining part is made by a magnetic material having a nonrectangular hysteresis characteristic.

The windings W.sub.1 and W.sub.1a , which are provided to magnetize the magnetic plate A or G in the reverse directions to each other, can be replaced by a single winding (W.sub.1a ). In this case, the drive currents iw.sub.1 and iw.sub.1a are conducted through this single winding W.sub.1 in the reverse directions to each other.

The construction of contacts used in the switch element of this invention will now be described. FIG. 5 is an example of the switching part of single-wire type, which is enclosed in a glass tube U. In this example, the movable small magnetic plate A which is composed of a single small magnetic plate of conductive material is connected at a point M by the use of a flexible connection line L to one of two terminal lines C and D. The above-mentioned two pairs of opposed magnetic poles of the fixed magnetic plate G are illustrated by dotted lines. The winding W.sub.1 is wound on the glass tube U. In the ON-state shown FIG. 5, the terminal lines C and D are connected to each other by the flexible connection line L and the movable small magnetic plate A, since the poles of the magnetic plate A are attracted as shown in FIG. 1 at the ON-state to the magnetic poles of the fixed magnetic plate G. If the thickness of the glass tube U is decreased as far as possible and the magnetic poles Q.sub.1, Q.sub.2, Q.sub.1a and Q.sub.2a are arranged closely to the glass tube U, the pole P.sub.1 is effectively attracted by the pole Q.sub.1 so as to close the contacts P and Q. It will be readily understood that the contacts P and Q are separated at the OFF-state.

The switching parts shown in FIG. 5 may be replaced by the switching parts shown in FIG. 6. In this example shown in FIG. 6, the movable small magnetic plate A is composed of three laminated plates A.sub.1, A.sub.a and A.sub.2. In this case, the plates A.sub.1 and A.sub.2 are conductive while the plate A.sub.a is insulative. The conductive plates A.sub.1 and A.sub.2 are connected respective flexible connection lines. In the ON-state shown in FIG. 6, two connecting circuits are formed by the terminal line C.sub.1, the flexible connection line, the conductive magnetic plate A.sub.1, contacts P.sub.1 and Q.sub.1 and a terminal line D.sub.1, and by the terminal line D.sub.2, the flexible connection line, the conductive magnetic plate A.sub.2, contacts and a terminal line C.sub.2. Accordingly, this double-wire type shown in FIG. 6 can control simultaneously two switching circuits.

With reference to FIG. 7, another example of the switch element of this invention comprises a U-shaped magnet A and a W-shaped magnet G, which have respectively a rectangular hysteresis characteristic and a magnetization characteristic of low residual flux density. The windings W.sub.1 and W.sub.1a are wound on the U-shaped magnet A for causing magnetization in reverse directions to each other. The winding W.sub.2 is wound on a center leg of the W-shaped magnet G to magnetize the magnetic poles of the magnet G as shown in FIG. 7 by way of example.

In this example, if drive currents iw.sub.1 and iw.sub.2 are passed into the windings W.sub.1 and W.sub.2 respectively as shown in FIG. 3, all the magnetic poles P.sub.1, P.sub.2, Q.sub.1, Q.sub.2 and Q.sub.3 are magnetized as shown in FIG. 7. Accordingly, the magnetic poles P.sub.1 and P.sub.2 are respectively attracted to the magnetic poles Q.sub.2 and Q.sub.3 as shown by dotted lines in FIG. 8 since the magnetic poles P.sub.1 and P.sub.2 are repelled from the magnetic poles Q.sub.1 and Q.sub.2 of the same polarity. This condition is maintained until the polarities of the magnetic poles are not changed. Thereafter, if drive currents iw.sub.2 and iw.sub.1a are passed through the windings W.sub.2 and W.sub.1a as shown in FIG. 3, the U-shaped magnet A is magnetized in the reverse direction to that shown in FIG. 7. Accordingly, the U-shaped magnet A is restored as shown in FIG. 8, since the magnetic poles P.sub.1 and P.sub.2 are attracted to the magnetic poles Q.sub.1 and Q.sub.2, respectively.

FIG. 9 shows an embodiment of this invention formed in accordance with the principle described with reference to FIGS. 7 and 8. In this embodiment, legs A.sub.1 and A.sub.2 of the U-shaped magnet A and the center leg G.sub.1 of the W-shaped magnet G are enclosed in a glass tube U. The legs A.sub.1 and A.sub.2 are made of a conductive, flexible magnetic material. Terminals C and D are provided respectively at the magnets A and G. An insulator R is provided at one side of the magnetic pole Q.sub.2 as shown in FIG. 9.

The condition shown in FIG. 9 corresponds to the ON-state of this switch element, in which the magnetic poles P.sub.1 and P.sub.2 are attracted to the magnetic poles Q.sub.1 and Q.sub.2 respectively so that the flexible leg A.sub.2 is contacted with the center leg G.sub.1. Accordingly, the conductive circuit from the terminal C to the terminal D is completed. In this case, if the magnetization direction of the U-shaped magnet A is reversed by flowing a drive current in the winding W.sub.1 or W.sub.1a , the magnetic poles P.sub.1 and P.sub.2 are attracted to the magnetic poles Q.sub.3 and Q.sub.2 respectively. However, since the leg A.sub.1 is separated by the insulator R from the center leg C.sub.1 of the magnet G, the conductive circuit from the terminal C to the terminal D is not completed. This condition corresponds to the OFF-state of this switch element.

The essential characteristics of the material of the U-shaped magnet A include its conductivity, flexibility, and its magnetic properties. In this case, it is not necessary that the flexible leg be resilient as in the conventional reed switch, since the ON-state and the OFF-state of this switch element are each maintained by the use of attractive force between different magnetic poles.

In the above examples shown in FIGS. 7, 8 and 9, it is assumed that one of the magnets A and G is fixed while the other is movable. However, both the magnets A and G may be movable. By way of example, even if the material of the W-shaped magnet G is also flexible, the same operation can be attained since the ON-state and the OFF-state of this switch element are each maintained by the use of an attractive force between different magnetic poles.

With reference to FIG. 10, an example of a matrix switching network using switch elements of this invention will be described. In this example, three row lines H.sub.1, H.sub. 2 and H.sub.3 and three column lines V.sub.1, V.sub.2 and V.sub.3 are shown for simple illustration. At each of the intersections of the row lines and column lines, switching contacts P.sub.11, P.sub.12, P.sub.13, P.sub.21, P.sub.22, P.sub.23, P.sub.31, P.sub.32 and P.sub.33 are each provided to switch-on or switch-off a connection between a corresponding one of the row lines H.sub.1, H.sub.2 and H.sub.3 and a corresponding one of the column lines V.sub.1, V.sub.2 and V.sub.3. Control parts S.sub.11, S.sub.12, S.sub.13, S.sub.21, S.sub.22, S.sub.23, S.sub.31, S.sub.32 and S.sub.33 control respectively the switch-on and the switch-off of the switching contacts. Windings W.sub.2.11, W.sub.1.11 and W.sub.1.11a correspond respectively to the windings W.sub.2, W.sub.1 and W.sub.1a of a switch element 11 (P.sub.11 and S.sub.11 ) arranged at the intersection of the row line H.sub.1 and the column line V.sub.1.

In operation, if the row line H.sub.1 is to be connected to the column line V.sub.2, drive currents Iw1 and Iw2 are flowed in lines W.sub.1.1 and W.sub.2.1, respectively, at a time T.sub.1 as shown in FIG. 11, so that all the contacts P.sub.11, P.sub.12 and P.sub.13 are switched into an OFF-state in accordance with control of the respective control parts S.sub.11, S.sub.12 and S.sub.13. At a time T.sub.1, a drive current Iw1a is flowed in a line W.sub.1.2 a under the flowing of the drive current Iw2 in the line W.sub.2.1, so that only the contact P.sub.12 is closed to connect between the row line H.sub.1 and the column line V.sub.2 in response to the ON-state of the control part S.sub.12. This closed condition of the contact P.sub.12 is maintained also after the termination of all the drive currents, as understood from the principle of this invention. In this case, the contacts P.sub.11 and P.sub.13 maintain the OFF-state after the time T.sub.1 while the contacts P.sub.22 and P.sub.32 maintain the respective prior states, since the movable magnet A assumes the same state even if the magnetic poles of the movable magnet A are reversely magnetized in response to the drive current Iw1a. Moreover, the states of other switch elements (S.sub.21, P.sub.21 ), S.sub.23, P.sub.23 ), (S.sub.31, P.sub.31 ) and (S.sub.33, P.sub.33 ) are not at all changed, since none of drive currents are conducted through the winding or windings of these switch elements.

The similar control of each of the switch elements can be performed by conducting, simultaneously, the drive currents Iw1 and Iw2 in the windings W.sub.1 and W.sub.2, respectively, and further by conducting a drive current Iw1a sufficiently larger than (e.g.; twice) the value of each the drive currents Iw1 and Iw2 as shown in FIG. 12. In this case, the windings W.sub.1 and W.sub.2 may be connected in series, as shown in FIG. 13, to perform the simultaneous flowing of the drive currents Iw1 and Iw2 while reducing the number of necessary terminals.

Claims

What we claim is:

1. A switch element, comprising:

a first magnet made of a ferromagnetic material having a substantially rectangular hysteresis characteristic, and having at least three magnetic poles,

a second magnet made of a magnetic material of low residual magnetic flux density and having two magnetic poles,

means for movably supporting at least one of said two magnets so that each of said two magnetic poles of the second magnet can close to each of a pair of magnetic poles of different polarities selected from said at least three magnetic poles of the first magnet,

a first control means for magnetizing the first magnet in either of two possible states,

a second control means for magnetizing the second magnet in a predetermined state, and

at least one pair of contact means for closing in response to movement of one said magnetic pole of one of the two magnets when the first magnet is magnetized by the first control means to a predetermined one of said two possible states, and for opening in response to the movement of said one magnetic pole of one of the two magnets when the first magnet is magnetized by the first control means to the other of said two possible states,

said first magnet and the second magnet forming a substantially closed magnetic circuit in both the opened and closed conditions of said pair of contacts to self-hold the condition selected.

2. A switch element according to claim 1, in which the first magnet comprises a U-shaped magnet having two legs, and having two magnetic poles of one polarity on one said leg and two magnetic poles of the other polarity on the other said leg, and in which the second magnet comprises a small bar magnet.

3. A switch element according to claim 1, in which the first magnet is a W-shaped conductive magnet having three legs each having a magnetic pole thereon, wherein two of said poles on said W-shaped magnet have the same polarity, and in which the second magnet is a U-shaped conductive magnet including two legs having magnet poles of different polarities.

4. A switch element according to claim 1, in which the second magnet is U-shaped and has two legs made of flexible, conductive and magnetic material.

5. A switch element, comprising:

a first magnet made of a magnetic material of low residual magnetic flux density and having at least three magnetic poles,

a second magnet made of a ferromagnetic material having a substantially rectangular hysteresis characteristic and having two magnetic poles,

means for movably supporting at least one of said two magnets so that each of said two magnetic poles of the second magnet can close to each of a pair of magnetic poles of different polarities selected from said at least three magnetic poles of the first magnet,

a first control means for magnetizing the second magnet in either of two possible states,

a second control means for magnetizing the first magnet in a predetermined state, and

at least one pair of contact means for closing in response to movement of one said magnetic pole of one of the two magnets when the second magnet is magnetized by the first control means to a predetermined one of said two possible states, and for opening in response to the movement of said one magnetic pole of one of the two magnets when the second magnet is magnetized by the first control means to the other of said two possible states, said first magnet and the second forming a substantially closed magnetic circuit in both the opened and closed conditions of said pair of contacts to self-hold the condition selected.

6. A switch element according to claim 5, in which the first magnet is a U-shaped magnet having two legs, and having two magnetic poles of one polarity on one said leg and two magnetic poles of the other polarity on the other said leg, and in which the second magnet comprises a small bar magnet.

7. A switch element according to claim 5, in which the first magnet is a W-shaped conductive magnet having three legs each having a magnetic pole thereon, wherein two of said poles on said W-shaped magnet have the same polarity, and in which the second magnet is a U-shaped conductive magnet including two legs having magnetic poles of different polarities.

8. A switch element according to claim 5, in which the second magnet is U-shaped and has two legs made of flexible, conductive and magnetic material.