US3005877A - Coordinate switch - Google Patents

Description

Oct. 24, 1961 R. NITSCH 3,005,877

COORDINATE SWITCH Filed April 2, 1958 6 Sheets-Sheet 1 R. NITSCH COORDINATE SWITCH Oct. 24, 1961 6 Sheets-Sheet 2 Filed April 2, 1958 v. m a

PP 1 A I! Oct. 24, 1961 R. NITSCH 3,005,877

' COORDINATE SWITCH Filed April 2, 1958 e Sheets-Sheet s FBJ M aizfy Oct. 24, 1961 R. NITSCH COORDINATE SWITCH 6 Sheets-Sheet 4 Filed April 2, 195a Oct. 24, 1961 R. NITSCH 3,005,877

COORDINATE SWITCH Filed April 2, 1958 6 Sheets-Sheet 5 I a i I I l Oct. 24, 1961 R. NlTSCH 3,005,877

COORDINATE SWITCH Filed April 2, 1958 6 Sheets-Sheet 6 dify United States Patent 3,005,877 COORDINATE SWITCH Rudolf Nitsch, Munich, Germany, assignor to Siemens and Halske Aktiengesellschaft Beriin and Munich, a

corporation oi? Germany Filed Apr. 2,1958, Scr. No. 726,006 Claims priority, application Germany Apr. 5, 1957 15 Claims. (Cl. 179-2754) This invention is concerned with improvements relating to coordinate switches of the type described in copending application Serial No. 573,039, filed March 21, 1956, and Patent No. 2,983,792, dated May 9, 1961, both owned by the assignee named in the present case, for use in signalling systems, especially telephone systems, such switches comprising mutually crossing line and row actuating coils as well as auxiliary holdingcoils which respectively embrace the entire corresponding line or row. The terms line and row are intended to designate difierent coordinate directions. At the crossing points of these coils are provided contact sets constructed of contact springs enclosed within protective tubing. The corresponding switch is provided with a magnetic shunt containing an iron path, serving to prevent actuation of the contacts responsive to energization of only a line coil or only a row coil. The iron path contained in the shunt consists of rectangularly abutting metallic strips or sheets disposed about the contact sets.

Theresult of the above indicated disposition of parts is a structure wherein pairs of metallic sheets or strips cooperate with the ends of the contact springs extending from the respective protective tubings, such strips being, for example, common to an entire row of the corresponding switch, and wherein the respective holding coils always embrace an entire line of the switch.

The various objects and features of the invention will be brought out in the course of the explanations which will be rendered below with reference to the accompanying drawings. In the drawings FIG. 1 shows the initially indicated parts of a switch and its tube-protected contact sets; other switch parts have been omitted to simplify representation and description; 7

FIG. 2 illustrates a switch with four crossing points each provided with a tube-protected contact set having four contacts;

FIGS. 3a and 3b represent an individual contact included in the structure according to FIG. 2;

FIG. 4 indicates in sectional view, taken at the contact spring air gaps, a contact structure according to FIGS. 3a and 3b;

FIG. 5 explains the non-uniform influence of the magnetic shunt on the springs of a contact;

FIGS. 6 and 7 show contact sets comprising magnetizable insert members to equalize or compensate the nonuniform eifect of the magnetic shunt;

FIG. 8 illustrates a contact set comprising compensating or equalizing inserts resulting from a combination of the features incorporated in FIGS. 6 and 7;

FIG. 9 explains the operation of a magnetizable insert;

FIG. 10 shows the use of permanently magnetized insert members in a switch; and

FIGS. 11a and 11b represent a contact set comprising four tube-protected contacts equipped with a magnetic shunt and with permanently magnetized insert members according to the invention.

Referring now to FIG. 1, showing the switch parts according to the initially indicated structure, when the holding coil H1 is energized, it will impress a magnetic flux on the tube-protected contacts embraced thereby, which will hold openatively actuated contacts in their actuated positions. It will be seen from FIG. 1 that a magnetic circuit will thereby result involving the contact sets I and II, the outwardly extending ends of the contact springs of which are magnetically coupled by means of the metallic strips of sheets Nl-NZ and N9-N10. The arrows pointing in FIG. 1 to the right indicating the direction of the corresponding fluxes. On the contact set II is thereby impressed an undesired flux extending in a direction opposite to the direction of the desired holding flux, as indicated by the arrows pointing to the left. In case the holding coil (not shown) disposed underneath the coil H1 should also be energized, the fluxes produced by the two holding coils would be superposed, causing weakening of the holding flux resulting with respect to one contact set. A complete compensation does not take place since the main part of the flux produced by one holding coil is closed by way of the iron path which embraces the contact sets in the manner of a cage. The consequence of the superimposing of the fluxes responsive to energization of two holding coils is, that stronger holding energization must be applied.

The invention, showing a way to void these difliculties, is thereby characterized that those of the pairs of metallic strips or sheets which efiect the magnetic coupling for the ends of the contact springs extending from the contact sets to the outside, at the side where the holding coil is disposed, are so arranged, that they do not produce a magnetic coupling between contact springs controlled by different holding coils.

The pairs of metallic strips forming the magnetic coupling for the ends of the contact springs which extend from the contact sets at the other side are advantageously likewise arranged so as to avoid magnetic coupling between contact springs controlled by other holding coils.

The result is a structure which provides for each contact set two outer metallic strips and two centrally disposed metallic strips, one outer pair of strips embracing one energizing or actuating coil, the other outer pair embracing the holding coil, and the centrally disposed pair of strips embracing the other actuating coil, whereby the metallic strips which embrace the actuating coils are interlocked by means of slots, thus providing the magnetic coupling for the movable parts of the contact springs at the air gap formed thereby.

FIG. 2 illustrates a structure which meets the above stated requirements. The figure shows four crossing points of a switch, each crossing point being provided with a tube-protected contact set comprising four contacts. Among the actuating coils of the switch are the line coil A, the row coil C and the holding coil H1. At the crossing point between the line coil A and the row coil C is disposed a contact set comprising four tube-protected contacts 11, 12, 13, 14. The holding coil H1 is embraced by a pair of metallic strips N7 and N8 which also form the magnetic coupling for the ends of the contact springs extending at the corresponding side from the protective tubings to the outside thereof. A pair of metallic strips N3 and N4 embraces the line actuating coil A in similar manner. Between the two pairs of strips N7, N8 and N3, N4 is disposed another pair of metallic strips N5, N6 which embraces the row actuating coil C. The pairs of metallic strips N3, N4 and N5, N6 are interlocked and form the magnetic coupling for the movable parts of the contact springs at the air gaps formed thereby.

A magnetic coupling affecting contacts sets which are not embraced by one and the same holding coil (as in FIG. 1), is in FIG. 2 only possible by stray flux passing through the air. Such stray flux will decrease in accordance with decreased magnetic impedance of the iron path affecting the ends of the contact springs. The centrally disposed metallic strips N5, N6 embracing the actuating coil C and the metallic strips N7, N8 embracing the holding coil H1 are for this purpose angularly bent in the direction of the contact spring sets. The bent portions abut and form the magnetic coupling for these pairs of metallic strips. The corresponding angular configuration provides for a large engaging surface, resulting in a low magnetic impedance, and also forms a shape which is favorable for the insertion of the coils. The entire structure is in the assembling of the parts pretensioned so that the pairs of metallic strips are for good magnetic contacting in mutually firm engagement.

FIGS. 3a and 312 show two views, with some parts in section, of the contact set and associated parts, included in the switch illustrated in FIG. 2, which is provided with the iron path of the magnetic shunt made in accordance with the invention and comprises the contact springs 11 to 14; FIG. 3a showing the contact set and associated parts as seen in FIG. 2 from the side and FIG. 3b showing the contact set and associated parts turned by 90 and looking down. For the sake of clarity, the parts of the iron path disposed in the direction of viewing FIGS. 3a and 3b respectively in front and in back of the contact set, have been omitted, thus showing in sections only the parts of the iron path positioned laterally of the contact set. The tube-protected contacts K are at their ends embraced by the pairs of metallic strips N3, N4 and N7, N8, respectively, such strips also respectively enclosing the line coil A and the holding coil H1. The portions of the metallic strips N3, N4 extending from the actuating coil A in straight manner beyond the protective tubes K to the left, thus forming openings at the side of the switch Where the line actuating coils are located through which the tube-protected contacts can be inserted. The metallic strips N7, N8 are, however, angularly bent in close proximity to the ends of the contact springs extending from the protective tubes. In case the spacing of the straight metallic strips N3, N4 from the ends of the contact springs extending from the protective tubes to the left, should result in undesirably high magnetic transition impedance with respect to such ends of the contact springs, magnetizable inserts may be used so as to provide the required magnetic connection. Disposed between the pairs of metallic strips N3, N4 and N7, N8 is the pair of metallic strips N5, N6 which interlock with the strips N3, N4, to provide the magnetic coupling for the contact springs at the air gap thereof, such strips N5, N6 being angularly bent to form portions lying close to the contacts. The pair of strips N5, N6 embraces the row actuating coil C. The right hand end walls of the strips N5, N6 abut similar left hand end walls of the strips N7, N8, thus interconnecting the corresponding strips magnetically.

FIG. 4 shows a section of the contact set of FIGS. 3a, 3b, taken along a line which intersects the air gap formed by the contact springs. The four tube-protected contacts K are enclosed Within the four metallic strips N3, N4, N5 and N6, as in a cage. It will be seen that the contact springs Fa lying close to the metallic strips N3, N4 have a better magnetic connection to these metallic strips than the contact spring Fi lying on the inside. The effect of the magnetic shunt with respect to the individual contact springs of the contact set is, therefore, non-uniform.

FIG. 5 explains the non-uniform influence of the magnetic shunt, illustrating only one tube-protected contact K engaged by a portion of the metallic strip N3. The non-uniform magnetic effect of the shunt is due to the different spacing of the contact springs F1 and Fa from the strip N3, spring Fa lying closer thereto than spring Fi. The effect of the magnetic shunt is, accordingly, undesirably weakened so far as the contact spring Pi is concerned.

This drawback may be avoided by the provision of magnetizable inserts placed between the individual tube-pro tected contacts to affect the contacts in the region of their air gaps.

FIGS. 6 and 7 show examples for the use of such incerts, the figures again showing contact sets each comprising four tube-protected contacts. In the case of FIG. 6, there is provided a vertically extending insert Zs, and in the case of FIG. 7, there is provided a horizontally extending insert Zp. These inserts are magnetically connected with the pairs of metallic strips which embrace the respective contact sets, causing deflection of the stray fluxes preferentially from the innermost contact springs F1. The inserts are advantageously held in suitable slots formed in the pairs of metallic strips so as to obtain good magnetic connections.

In the structure according to FIG. 7, the wide surfaces of the contact springs are always opposite a metallic strip or an insert, respectively, thus providing an effect of the magnetic shunt on both contact springs of such contact which is more uniform than in FIG. 6.

FIG. 8 shows a combination of the features of FIGS. 6 and 7. There are provided inserts Zp and Zs in crossing relationship, thus forming for each contact an individual cage which encloses the contact symmetrically and thereby elfecting the most uniform action of the magnetic shunt on the individual contact springs.

The inserts may also serve for producing a particular effect, namely, to reduce the expenditure required for the energization :of the holding coils. The inserts are for this purpose permanently magnetized parallel to the axis of the tube-protected contacts so as to obtain closure of the resulting stray flux across the contact air gap. Such a permanently magnetized insert may be disposed in parallel with or perpendicular to the contact springs.

The cost of hard magnetic material represents an important item and it is therefore advantageous to place the permanently magnetized insert so that it can perform in the best possible manner, thereby reducing the use of the expensive material to a minimum. This will be the case when the permanently magnetized insert is disposed in parallel with the contact springs, as shown in FIG. 7. For example, the insert Zp, in FIG. 8, may be made of magnetically hard material and the insert Zs may be made of magnetically soft material.

The operation of the permanently magnetized insert may be explained with reference to FIG. 9, showing a tube-protected contact K comprising contact springs Pa and Ft. The metallic strip N3 and the permanently magnetized insert Zp are disposed opposite one another in the region of the air gap between the contact springs Fa, Fi. The insert produces a stray flux flowing in the direction of the arrows, such flux closing across the air gap and thus exerting upon the contact springs an attractive force; such force is, however, by itself insuflicient to hold the contact in actuated position and is, of course, wholly inadequate to effect operative actuation of the contact. Flux produced by the insert Zp flowing across the contact air gap in the same direction as the flux produced by the holding coil will support the latter, and the expenditure required for the energization of the holding coil can accordingly be reduced; if the fluxes flow in opposite directions, it will be necessary to provide for stuonger energization of the holding coil. Either effect may gain importance with respect to various operating requirements.

The material to be used for the permanently magnetized inserts should be adapted for rolling and machining including cutting, so as to facilitate the shaping of the inserts.

FIG. 10 shows a structure employing permanently magnetized inserts according to FIG. 9. The illustrated switch has four crossing points each with a contact set comprising four tube-protected contacts. Accordingly, there are two line control coils A and B, two row control coils C and D, and two holding coils H1 and H2. The permanently magnetized inserts, indicated at Zpl and Z 22 are respectively common each to a row. The direction of magnetization of the insert Zpl is indicated by the arrow.

FIGS. 11a and 11b are two part sectional views of a contact set comprising four tube-protected contacts and provided with the magnetic shunt and the inserts according to the invention. The structure is generally similar to that shown in FIGS. 3a, 3b and identical parts are, therefore, identically referenced. FIG. 11b shows the contact set rotated with reference to FIG. 11a by 90. The parts of the iron path lying in viewing direction respectively in front and in back of the contact set have again been omitted, only the parts being shown in section which lie laterally of the contact set. Within the region of the contact air gap are disposed the inserts Zp and Zs. The inserts and also the metallic strips serve advantageously a whole line and a whole row of the switch. Such inserts also appearin FIGS. 2 and 10.

In FIG. 2, the corresponding inserts are marked Zp and Zr. They extend thnough the contact sets and the pairs of metallic strips N5, N6 and N3, N4- within the region where the metallic strips engage the tube-protected contacts. The inserts are held in slots formed in these metallic strips.

Changes may be made within the scope and spirit of the appended claims.

I claim:

1. A coordinate switch for use in a signalling system, said switch having a plurality of similarly disposed contact sets transversely aligned in two coordinate directions, each contact set comprising a plurality of tube-protected contacts with the ends of the corresponding contact springs extending outwardly, and having a first actuating coil embracing a plurality of contact sets aligned in one coordinate direction and a second actuating coil disposed in crossing relationship with respect to said first coil and embracing a plurality of contact sets aligned in the other coordinate direction, and including a holding coil common to the contact sets embraced by one of said actuating coils, and further having a magnetic shunt containing an iron path formed by rectangularly abutting metallic strips which enclose the contact set disposed at the crossing point of said first and said second actuating coils, said iron path being operative to effect magnetic coupling-with respect to said outwardly extending ends of the contact springs of the corresponding contact set, the metallic strips forming said iron path in the vicinity of said holding coil extending with respect to the correspondingly placed outwardly extending ends of said contact springs so as to efiect responsive to energization of said holding coil solely magnetic coupling of said correspondingly placed ends of said contact springs and thus avoiding magnetically aflecting neighboring contact springs operatively associated with other holding coils.

2. A coordinate switch according to claim 1, wherein said iron path enclosing said contact set comprises two pairs of outer metallic strips respectively embracing said contact set at the opposite ends thereof, a further pair of metallic strips embracing such contact set within a region lying intermediate said first named two pairs of outer metallic strips, one of said pairs of outer metallic strips embracing one of said actuating coils, the other pair of said outer metallic strips embracing said holding coil, said further intermediate pair of metallic strips embracing the other one of said actuating coils, and means for mechanically interlocking the two pairs of strips which respectively embrace said actuating coils to provide magnetic connection therebetween which is upon energization of said actuating coils effective to produce a flux flowing across the air gap formed by the contact springs of said tube-protected contacts.

3. A coordinate switch according to claim 2, wherein the ends of the metallic strips of said intermediate pair and the ends of the metallic strips of the outer pair which embrace said holding coil are respectively angularly shaped, such angularly shaped ends of said strips abutting to connect the respective pairs of strips magnetically.

4. A coordinate switch according to claim 1, comprising magnetically conductive insert means disposed between certain pairs of adjacent tubes of said contact set with the contacts of one tube of a pair disposed at one side of said last mentioned means and those of the other tube of such pair disposed at the other side of said last mentioned means, the magnetic flux produced by said insert means atfecting the region of said contacts including the air gap formed by the corresponding contact springs, said inserts being magnetically interconnected with the metallic strips embracing the corresponding contact set along such regions.

5. A coordinate switch according to claim 2, comprising magnetically conductive insert means disposed between certain pairs of adjacent tubes of said contact set with the contacts of one tube of a pair disposed at one side of said last mentioned means and those of the other tube of such pair disposed at the other side of said last mentioned means, the magnetic flux produced by said insert means afiecting the region of said contacts including the air gap formed by the corresponding contact springs, said inserts being magnetically interconnected with the metallic strips embracing the corresponding contact set along such regions.

6. A coordinate switch according to claim 3, comprising magnetically conductive insert means disposed between certain pairs of adjacent tubes of said contact set with the contacts of one tube of a pair disposed at one side of said last mentioned means and those of the other tube of such pair disposed at the other side of said last mentioned means, the magnetic flux produced by said insert means affecting the region of said contacts including the air gap formed by the corresponding contact springs, said inserts being magnetically interconnected with the metallic strips embracing the corresponding contact set along such regions.

7. A coordinate switch according to claim 1, comprising permanently magnetizable insert means disposed between certain pairs of adjacent tubes of said contact set with the contacts of one tube of a pair disposed at one side of said last mentioned means and those of the other tube of such pair disposed at the other side of said last mentioned means, said insert means being magnetized in a direction extending in parallel to the axes of said tubeprotected contacts, the stray flux produced by said insert means flowing across the air gap formed by the corresponding contact spring.

8. A coordinate switch according to claim 2, comprising permanently magnetizable insert means disposed between certain pairs of adjacent tubes of said contact set with the contacts of one tube of a pair disposed at one side of said last mentioned means and those of the other tube of such pair disposed at the other side of said last mentioned means, said insert means being magnetized in a direction extending in parallel to the axes of said tube protected contacts, the stray flux produced by said insert means flowing across the air gap formed by the corresponding contact spring.

9. A coordinate switch according to claim 3, comprising permanently magnetizable insert means disposed between certain pairs of adjacent tubes of said contact set with the contacts of one tube of a pair disposed at one side of said last mentioned means and those of the other tube of such pair disposed at the other side of said last mentioned means, said insert means being magnetized in a direction extending in parallel to the axes of said tubeprotected contacts, the stray flux produced by said insert means flowing across the air gap formed by the corresponding contact spring.

10. A coordinate switch according to claim 4, wherein said insert means is common to a plurality of contact sets disposed in a predetermined coordinate direction.

11. A coordinate switch according to claim 5, wherein said insert means in common to a plurality of contact sets disposed in a predetermined coordinate direction.

12. A coordinate switch according to claim 6, wherein said insert means is common to a plurality of contact sets disposed in a predetermined coordinate direction.

13. A coordinate switch according to claim 7, wherein said insert means is common to a plurality of contact sets disposed in a predetermined coordinate direction.

14. A coordinate switch according to claim 8, wherein said insert means is common to a plurality of contact sets disposed in a predetermined coordinate direction.

15. A coordinate switch according to claim 9, wherein disposed in a predetermined coordinate direction.

2,187,115 2,245,391 2,289,830 2,324,623 2,332,338 2,397,123 said insert means is common to a plurality of contact sets 10 2,836,676

References Cited in the file of this patent UNITED STATES PATENTS Ellwood Jan. 16, Dickten June 10, Ellwood July 14, Hickman July 20, 1943 Peek Oct. 19, Brown Mar. 26, Wirth May 27,

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