A GALVANIC SWITCH

Abstract: The present invention relates to a galvanic switch for electrically making or breaking one cross-point among a plurality of cross-points in a three-dimensional switching matrix. The switch includes electrical contact lines (16), first links (17) which extend perpendicular to the contact lines, and second links (18) which extend perpendicular to both the contact lines and the first links. At each cross-point, there is located a contact element (10) in the form of a spherical element for making and breaking the electric contact respectively. The contact elements either make or break the cross-point depending on whether the coupling element is conductive (15) or non-conductive (14), and are manoeuvered by manoeuvering elements (11, 12, 13). In a first selection, first manoeuvering elements (11) are manoeuvered so as to move all coupling elements simultaneously in a chosen first plane (x-y) of cross-points, where-after second manoeuvering elements (12) are manoeuvered so as to move simultaneously all of the coupling elements moved by the first manoeuvering element (11) in the intersection between the first selected plane and a selected second plane (y-z) of cross-points. Manoeuvering of third manoeuvering elements (13) for moving the coupling element moved by the first and the second manoeuvering elements in the intersection between the selected second plane (y-z) and a selected third plane (x-z) is utilized as a coupling function for bringing into the cross-point a coupling element of opposite kind to the coupling element already present in the cross-points.

Description: A GALVANIC SWITCH TECHNICAL FIELD The present invention relates to a galvanic switch for electri¬ cally making or breaking one cross-point among a plurality of cross-points in a three-dimensional switch or connector matrix, wherein each of said cross-points may comprise of one or more conductors, including electrical contact lines which extend in a first direction; first links which extend perpendicularly to said contact lines; second links which extend perpendicularly to both the contact lines and the first links, wherein each contact line, first link and second link, is comprised of a corresponding number of conductors, electrical contact elements at each cross-point for making or breaking electrical contact between the conductors of the contact lines and the conductors of the first or the second links respectively, andmanoeuveringelements formanoeuveringthe contact elements atsaidcross-point, including firstmanoeuvering elements which are parallel with the contact lines and can be moved parallel thereto, second manoeuvering elements which are parallel with the first links and can be moved parallel thereto, and third manoeuvering elements which are parallel to the second links and can be moved parallel thereto. BACKGROUND ART Many versions of galvanic switching devices or connectors of different kinds have been known to the art for a number of years. Such switches have been revitalized for use with controllable cross-connectors. The ball switch belongs to this switch category. The requirement for cross-connectors is found in many fields, with the size of such connectors varying from some tens of lines to some tens of thousands of lines and for frequencies between just a few kHz to some hundreds of MHz. The difficulty is found in producing simple units of this kind at low cost and in small volumetric sizes and which are not power consuming once having operated. In many applications, the switches are in operation only a few times each year. The known switches are normally of the x-y selector type, i.e. selection is effected in two planes, for example the code selec¬ tor, the coordinate selector, the ball selector or ball switch. In order to enable larger switching or selector networks to be constructed, it is necessary to connect these switches in several stages with the aid of link coupled systems, for instance a system of the kind illustrated in Figure 1. As will be seen from the Figure, link coupling results in serious problems, such as requiring large quantities of cable, rotation of the links between the various stages, and the provision of different manoeuvering devices for manipulation of the various selector modules. Furthermore, in the case of cross-connectors, it is undesirable to differentiate between In and Out as in the Figure 1 illustration. This can be achieved by coupling i with u , and coupling i with u , and so on. This results in a so-called folded selector network 2 whichmay have the configuration shown inFigure 2. The aforemen¬ tioned problem prevails, however. The aforesaid problems can be solved bymeans of a switch of cubic construction. The cube incorporates several selector stages in a manner which excludes the aforementioned links, i.e. link cabling is not necessary. Rotation of the links has been achieved by uti¬ lizing all of the x-y and z-directions, i.e. with the aid of a three-dimensional coupling field with electric contacts in three dimensions. Manoeuvering is accomplishedbyutilizing a selection in three dimensions common for all selector stages in the cube. The x, y and z-planes have been utilized to form the link-coupled structure and a plurality of selectors in one and the same unit. Figure 2 illustrates the link coupling structure. This structure can be drawn in a manner of the structure shown in Figure 3, and a configuration according to Figure 4 can be obtained by moving the centre stages in between the contacts inthe first selector stage. Each cross-point may consist of one or more conductors having a contact function, for instance similar to the ball switch or some other manoeuverable contact function. It is not necessary to have external access to the links y and z, and consequently all con- nections to the coupling field are effected from one side. The contact function shall be mechanically bistable. Switches of the aforedescribed kind are known to the art. One drawbackwith switches of this kind, however, is that manoeuvering of a selected cross-point, i.e. the choice of x, y and z-coor- dinates, is effected bymeans of individual manoeuvering means for the respective different coordinates. The switch therefore includes a large number of manoeuvering means and the switch as a whole is unnecessarily expensive and space consuming. It is not possible to reset the switch quickly and simply, but requires individual manoeuvering of all cross-points, therewith taking a long time to reset. DISCLOSURE OF THE INVENTION The object of the present invention is to eliminate the drawbacks of known switches of the aforesaid kind, and to provide a galvanic switch of simple construction which will operate quickly and reliably and which is inexpensive and does not require a large amount of space. This object is achieved with a switch having the characteristic features set forth in the accompanying Claims. Manoeuvering of the cross-points in the cube is effected in¬ dividually. A cross-point is indicated and manoeuvered in the x, y and z-plane, by selecting a contact element, for instance a ball, by effecting three movements in the x, y and z-planes. Figure 5 illustrates the principle on which the choice is made. A first choice function results in movement of all contact elements in a single plane, for instance in the x-direction or x- plane. During this movement, the contact elements take a position in which movement of one plane in the y-direction will only move those contact elements which form intersections between the x-y plane and the y-z plane. During movement of a plane in the y direction, the contact elements which form intersections between the x-y plane and the y-z plane take a position in which they can be influenced by a plane in the z-direction. Thus, there is indicated a point in the space in the intersection plane between the x-y plane, the x-z plane and the y-z plane. Movement in the z- plane can be used advantageously for switching a contact function on and off. The planes are preferably moved with the aid of electromagnets or hydraulic devices positioned on the sides of the cube selector. Thevariousplanes areconstructed frommanoeuveringelements, for instance in the form of bars or cams, with the contact elements positioned so as to be moveable in the x, y and z-direction, as shown in Figure 5. Theplanes are obtained by joining together the outer edges of the bars, so that the bars can be manoeuvered together in a single plane, as described above. The cube selector is constructed by combining the aforedescribed contact function with the manoeuvering function described above, so as to form a unit, i.e. a cube switch or selector. The invention will now be described in more detail with reference to a preferred exemplifying embodiment thereof and also with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figures 1-4 illustrate in principle the manner in which a switch network can be formed into a three-dimensional cross connector module. Figure 5 illustrates in principle the manoeuvering function in a cross-point of a galvanic cross connector constructed in accor¬ dance with the present invention. Figure 6 illustrates inprinciplethe on/off switching function at a cross-point. Figure 7 illustrates the contact function between contact lines and first links with a closed and a broken contact respectively at two cross-points. Figure 8 illustrates the contact function between contact lines and second links with a closed and a broken contact respectively at two cross-points. Figure 9 illustrates the manoeuvering elements and their mutual relationship in the three-dimensional connector matrix. BEST MODE OF CARRYING OUT THE INVENTION Figure 5 illustrates in principle the manner of manoeuvering a switch cross-point. Three different types of manoeuvering elements, each including several bars, are used to move an electric contact element located in the vicinity of the selected cross-point. The contact elements have the form of spherical connector elements, or balls, of which half are electrically conductive and the remainder electrically insulating, so as to make or break an electric connection at the cross-point. For the sake of simplicity, only one bar has been shown in each manoeuve¬ ring element, and no contact lines or links have been shown in this Figure for the same reason. A bar 11a, referred to here as the x- bar, included in a first manoeuvering element 11, can be displaced in the x-direction according to the Figure, from a neutral position, shown in broken lines, to an activated position. A contact element 10 which was initially located outside the cross- point although in the vicinity thereof, in a recess in the bar in position 1, is therewith moved by the bar 11a to position 2 and inserted into a recess in a bar 12a, the y-bar, included in a second manoeuvering element 12, said y-bar being moveable perpendicularly to the bar 11a in the y-direction. The bar 12a is then moved from its neutral position, shown in broken lines in the Figure, to an activated position, said contact element 10 being moved to position 3 and inserted into a recess in a bar 13a, the z- bar, included in a third manoeuvering element 13. As indicated in broken lines, the bar 13a can be moved perpendicular to both the bar 11a and the bar 12a in the z-direction, and is used as an off/on function to move the contact element 10 to position 4, as explained in more detail herebelow. Located at each cross-point is a ball train consisting of three contact elements 10. In the starting position of the selector switch, i.e. the state in which no cross-point is activated, the ball train includes two insulating balls 14 and an intermediate, conductive ball 15. The insulating balls are positioned between contact lines and contact tongues in contact links, as described herebelow. Figure 6 illustrates in the lowerpart the position of the ball train in the bar 13a, in the neutral position, whereas the upper part of the Figure illustrates the activated, or switched-on state of the switch. As will be seen from Figure 6, the ball receiving recess in the bar 13a has a width which corresponds to five ball-diameters. In the neutral position, the bar 13a takes a position in which the ball train is located centrally in the recess, with an empty space corresponding to the diameter of one ball at each end of the train. When manoeuvering the cross-point by means of the manoeuvering elements 11 and 12, the ball which initially lay outside the cross-point although in the vicinity thereof, position 1 in Figure 5, enters the recess of the bar 13a either at the top or at the bottom of the ball train, position 3. It should be noted that two x-bars 11a and two y-bars 12a are provided for each cross-point, although only one pair of such bars has been shown in the Figures, for the sake of clarity. The pair of x and y-bars not shown in the drawing is disposed in the space in the recess of the z-bar present on the opposite side of the ball train. When the z-bar 13a is moved downwards in Figure 6 , the contact element 10 in position 3 will move the ball train down¬ wards, therewith replacing an insulating ball 14 with a conductive ball 15 and vice versa. The bottom part of Figure 6 illustrates the state of the switch prior to moving the z-bar, while the upper part of the Figure shows the state of said switch subsequent to moving said bar. When the y-bar and x-bar are returned, the manoeuvering elements 12 and 11 are deactivated in that order and the contact element is returned to its original position 1, outside of the cross-point although in the vicinity thereof, as shown in Figure 5, but is now located in the other pair of x and y- bars. Having described the actual manoeuvering function above, the electrical contact function will now be described in more detail with reference to Figures 7 and 8. The switch includes contact lines 16 which extend parallel to the x-bars 11a of the manoeu- vering elements 11 and to which external incoming and outgoing lines are connected. Cross-connection is also achieved with the aid of first links 17 which extend parallel with the y-bars 12a of the manoeuvering elements 12, and second links 18 which extend parallel with the z-bars 13a of the manoeuvering elements 13. The links 17 and 18 are used solely to achieve the actual cross connection within the switch and no external access is necessary. Also shown in Figure 7 are two cross-points with contact lines 16 and first links 17 respectively, wherein the upper part of the Figure shows a closed or activated cross-point with electric contact achieved through the conductive balls 15 located between the respective lines 16 and links 17, whereas the bottom part of the Figure illustrates an electrically broken cross-point. The first links 17 are provided with tongues 19 at the actual contact point itself. In the illustrated embodiment, the contact lines 16 have the form of round rods provided with V-shaped grooves 20, and the tongues 19 are pitted with depressions or provided with holes 21 for the intention of providing a surface which will hold the ball train in position. Figure 8 illustrates, in a similar manner, two cross-points with contact lines 16 and second links 18 respectively. The upper part of this Figure also illustrates an activated cross-point and the lower part of the Figure an electri¬ cally broken cross-point. Similar to the links 17, the links 18 are provided with contact tongues 19, which are also embossed, pitted or configured in some other way with the purpose of holding the ball train in position. Thus, the contact function and manoeuvering function in the illustrated switch are achieved with the aid of balls, as in a ball switch. An electrical contact is made or broken by moving a ball train which consists of two insulating and one conductive ball, by means of another conducting ball, or by moving a ball train which consists of one insulating and two conductive balls by means of another insulating ball. Balls and contact lines are positioned in contact blocks in which manoeuvering bars are also found. The switch is switched on and off, by moving the balls with the aid of a z-bar in which the distance between the pins equals the combined diameters of five balls. As illustrated in the drawings, one ball is located outside of the cross-point, although in the vicinity thereof. The bars on both sides of the contact block are joined together and are moved pairwise when moving in the x and y- directions. After manoeuvering a cross-point (including two contact lines in the illustrated embodiment) , the ball which lies outside the ball train will enter a recess in the y-direction bars. When the y-direction bar is moved, this ball will then be moved to a position which is not in the position of the ball train, and hence only three balls will be left in the z-direction bar. In this new operational state, the ball will enter a recess in the x-direction bars, which, in turn, move the balls to their neutral position. At the beginning of a manoeuvering operation, all balls inthe cube are in their neutral positions. By connecting all bars in the x-direction, as illustrated in Figure 9, in which the x- bars 11a are mutually connected in two planes to the manoeuvering elements 11, which lie in a plane x-y, all balls in this plane can be moved from their neutral position to a central position. The balls located in the central position can now be moved with the y- bars 12a, which are connected to the manoeuvering elements 12 in a plane y-z perpendicular to the x-direction plane. When these y- direction bars are moved to the manoeuvering position, all balls which are located in a row in the intersection between the two planes will follow saidmovement to themanoeuvering position. By mutually connecting the z-direction bars 13a to the manoeuvering elements 13 in a plane perpendicular to the y-z plane, only one of the balls now located in the manoeuvering position will be moved in response to movement of the z-direction bar, therewith manoeuvering only one cross-point. During this manoeuvering operation, one ball will enter the position of the ball train and a corresponding ball on the other side will enter the y-direction bar which forms the pair for the cross-point. This ball is returned to the manoeuvering position in accordance with the aforegoing. The surfaces of the contact tongues are embossed or likewise roughened, so as to hold the balls firmly between the contacts. As will be evident from the earlier Figures, the x-contact lines have the form of straight conductors. The cube can be constructed from a plurality of plastic plates incorporating the y-links and the z-links. The plastic plates are then assembled to form a larger block (a cube) . Because the x-conductors are straight, they can be inserted through a slot transversely to the plates. The plates are configured to enable the bars to be inserted into a cube which has already been assembled. The balls are positioned in the cube, by placing said balls in respective compartments when inserting the z-bar and advancing the z-bar incrementally so as to press said balls into the cube. At the end of this ball-charging or ball-positioning operation, all balls will be located in a manoeuvering position and by moving all z-bars to/from, all contacts will lie in the off-position. As the balls are being loaded, the x and y-bars are in an activated position, therewith enabling all balls to be moved to their starting positions, by first deactivating all y-bars and then all x-bars. This operation can also be used for "resetting" purposes, i.e. to switch-off all cross-points without needing to manoeuver all cross-points individually, although this may be necessary should controlling equipment lose information as to which cross-points have been set. Both the bars and the contact lines are through-passing, which means that large units can be constructed, by stacking several cubes on top of one another, adjacent one another and behind one another. This enables very large units to be constructed from smaller basic models. Manoeuvering is effected with the aid, for instance, of electro- magnets placed in manoeuvering modules on four sides of the cube. The manoeuveringmodules interconnect and manoeuver the cams. The four sides of the cube are used for x, y and on/off. The x and y bars are held deactivated by means of springs for instance, and the on/off bar or the z-bar is held in its central position when none of the on-coils or off-coils have been energized. All cabling inputs are on one side of the cube. Inthe describedand illustrated embodiments, each cross-pointhas two conductors. It will be understood, however, that the cross- points may include only one conductor, in which case the ball trains in the z-bars will consist of one single ball and have a correspondingly smaller recess in the bar. Similarly, cross- points may include more than two conductors, in which case the ball trains and the recesses in the z-bars will be correspondingly larger. It will also be understood that the configuration and positioning of the contact conductors and the links may also be modified so as to function in the intended manner. The invention is, of course, not restricted to the aforedescribed and illustrated embodiments, since these embodiments can be modified within the scope of the following Claims.

Claims: CLAIMS 1. A galvanic switch for electrically making or breaking one cross-point among a plurality of cross-points in a three-dimen¬ sional coupling matrix, wherein each of said cross-points may consist of one or more conductors, including electrical contact lines which extend in a first direction, first links which extend perpendicularly to said contact lines, second links which extend perpendicularly to both the contact lines and the first links, wherein each contact line, first link and second link, is com- prised of a correspondingnumber of conductors, electrical contact elements at each cross-point for making or breaking electrical contact between the conductors of the contact lines and the conductors of the first or the second links respectively, and manoeuvering elements for manoeuvering the contact elements at said cross-point, including first manoeuvering elements which are parallel with the contact lines and can be moved parallel thereto, second manoeuvering elements which are parallel with the first links and can be moved parallel thereto, and third manoeuvering elements which are parallel to the second links and can be moved parallel thereto, c h a r a c t e r i z e d in that the contact elements (10) are comprised of spherical coupling elements (14, 15) arranged in and adjacent each cross-point; in that the first manoeuvering elements (11) are disposed in first planes (x-y) parallel with the contact conductors (16) and the first links (17) in order to move all coupling elements simultaneously adjacent respective cross-points in a selected cross-point plane; in that the second manoeuvering elements (12) are disposed in second planes (y-z) parallel with the first links (17) and the second links (18) in order to move simultaneously all of the coupling elements moved by the first manoeuvering elements (11) in the intersection between the first selected plane and the selected second cross-point plane; and in that the third manoeuvering element (13) are disposed in third planes parallel with the contact conductors (16) and the second links (18) in order to move the coupling elements moved by the first manoeuvering elements (11) and the secondmanoeuvering elements (12) in the intersection between the second selected plane and the third selected plane, said coupling elements (10) , upon mechanical activation of respective manoeuvering elements, being moved so as to establish contact with the contact conductors (16) and the first links (17) or the second links (18) in order to make or break the cross-point electrically, depending on whether the coupling element (14, 15) is electrically conductive (15) or electrically non-conductive (14) , and in that manoeuvering of the third manoeuvering elements (13) is used as a coupling function for bringing into the cross- point a coupling element of a kind which is opposite to the kind of element that is already located in the cross-point. 2. A galvanic switch according to Claim 1, cha r acter i ¬ z e d in that the manoeuvering elements (11, 12, 13) comprise recessed bars (11a, 12a, 13a) provided with recesses for accom¬ modating the coupling element (14, 15) . 3. A galvanic switch according to Claim 1, ch a ra ct e r i ¬ z e d in that the coupling elements (14, 15) are comprised of a ball train located in the cross-points and alternating with electricallyconductive (15) and electricallynon-conductive (14) balls. 4. A galvanic switch according to Claim 1, c h a r a c t er i ¬ z e d in that the first and the second links (17, 18) include contact tongues (19) ; and in that the coupling elements (14, 15) are disposed between the contact conductors (16) and the contact tongues (19) of said links. 5. A galvanic switch according to Claim 4, c h a r a cte r i ¬ z e d in that the contact tongues (19) are embossed or roughened in some other way for holding the coupling elements in position. 6. A galvanic switch according to Claim 1, c h a r a cter i ¬ z e d in that themanoeuvering elements (11, 12, 13) are activated in one direction by electromagnets and in the other direction by return springs.

Inventors: ROOS STURE GOESTA, ROOS, STURE, GOESTA
Applicants: ERICSSON TELEFON AB L M, TELEFONAKTIEBOLAGET LM ERICSSON
Application year: 1992
Main classification: H01H67
IPC codes: H01H67