US3083280A

US3083280A - Teletechnical circuit comprising relays or relay selectors

Info

Publication number: US3083280A
Application number: US772822A
Authority: US
Inventors: Ungar Ernest
Original assignee: Spectralink Europe APS
Current assignee: Spectralink Europe APS; Kristian Kirks Telefonfabrikker AS
Priority date: 1957-11-16
Filing date: 1958-11-10
Publication date: 1963-03-26
Anticipated expiration: 1980-03-26
Also published as: FR1214361A; DK96062C; BE572984A; GB904270A; DE1107724B

Description

March 26, 1963 E. UNGAR 3,083,280

TELETECHNICAL CIRCUIT COMPRISING RELAYS OR RELAY SELECTOR-S Filed Nov. 10, 1958 2 Sheets-Sheet 1 Fig.1

March 26, 1963 E. UNGAR 3,083,280

TELETECHNICAL CIRCUIT COMPRISING RELAYS 0R RELAY SELECTORS Filed Nov. 10, 1958 2 Sheets-Sheet 2 United States Patent 3,083,280 TELETECHNICAL CERCUIT COMPRISING RELAYS OR RELAY SELECTORS Ernest Ungar, Horsens, Denmark, assignor, by mesne assignments, to Industris-eiskahet Kristian Kirks Telefonfabriker A/S, Copenhagen, Denmark Filed Nov. 18), 1958, Bar. No, 772,822 Claims priority, application Denmark Nov. 16, 1957 15 (Ilaims. (Cl. 200-104) The invention relates to a telecommunication circuit comprising relays or relay selectors, for example, subscribers circuits, connecting circuits, register circuits or relay selectors having a multiple of the type, in which the connecting leads and fixed contacts are placed on one or more carrier plates in the form of printed wiring.

As is known, printed wiring consists of an electrically conductive coating on a plate of insulating material. Such wiring may by way of example be produced by printing, plating, spraying-on or bonding-on of a conductive material, e.g., a metal, on the carrier, or by removal, for example, by etching or sand blasting of portions of a metal coating on the carrier.

The known telecommunication circuit of the type in question is so designed that each relay contact is divided into two series-connected contacts, where the two fixed contacts of the double contact set thus formed are placed on the same carrier plate in connection with their associated conductors of the printed network. The associated two movable contacts are placed on a common contact spring either each at one end of the contact spring or side by side on the contact spring or, on two electrically connected contact springs. Said contact spring or springs or, a number of such springs or pairs of springs is/ are together with a relay magnet assembled to make a unit, which is screwed on to the carrier plate of the printed wiring, so that the movable contacts are placed in the correct position in relation to the fixed contacts. Thus, each connection is led from a fixed contact on the carrier plate via a corresponding movable contact and one or two contact springs to the subsequent movable contact and from there to another fixed contact on the carrier plate.

Several drawbacks are attached to this construction. Firstly, the assembling of the movable contacts and the relay magnet on the plate must be effected with the greatest accuracy in order to be sure that the contacts are placed accurately in the correct position in relation to the fixed contacts, and likewise the adjustment of the movable contacts cannot be effected until the unit is mounted on the carrier plate.

Secondly, with a view to the function it must be considered a drawback that two series-connected contacts are to be used for each connection, in that the risk of contact faults is thereby at least doubled.

Finally, it is obvious that the use of two movable contacts for each connection insteadot a single contact means a considerable increase in costs.

The use of the printed wiring involves, however, in itself such material advantages that it must be considered of extremely great importance to make use of it within the field of telecommunication. Consequently, the invention has for its object to provide a telecommunication circuit of the type specified above but where the said drawbacks are eliminated.

According to the invention this is obtained by the movable contacts being constituted of, or permanently connected with, conductors on the printed wiring.

That the contacts are constituted by, or permanently connected with, the said conductors, is to be so understood that the contacts are either constituted by parts of the conductors proper, or that on the said conductors, contact buttons or contact springs are secured, which at their free ends carry the actual contacts. By the construction according to the invention, the very important advantage is obtained that all relay contacts of the telecommunication circuit together with the wiring, may be assembled into a unit, and may be adjusted prior to the placing of the driving systems of the relays. The wiring, on which the movable contacts are placed, may be the same printed wiring as the one on which the fixed contacts are made, the movable contacts being in such case constructed as contact springs, one end of which is secured to the printed wiring, e.g., by soldering or by means of connecting rivets or a conductive adhesive, whereas the other end of the said springs, which serves for establishing contact, is situated opposite the said fixed contacts on the wiring. The printed wiring, on which the movable contacts are situated, may however also be an independent wiring, in that the movable contacts may by way of example be de signed as cam-like portions of a plate having printed wires, the cam teeth of said portions and the metal coating applied thereto being designed with sufiicient elasticity to act as contact springs. The word printed has here the same scope as above in the term printed wiring."

A particularly advantageous embodiment is according to the invention, obtained by the contacts being placed in consecutive rows with constant spacing, and the contact springs for the make and break contacts being alike.

This construction involves different advantages with respect to the manufacture. The constant contact spacing simplifies the production, the placing of the. contacts and the arrangement of the wires; only a single type of contact springs is required, and the assembling of the springs is the same no matter whether it is a make contact or a break contact.

Especially in the last mentioned embodiment, but nevertheless also in other embodiments of the invention, it is, according to the invention, particularly advantageous that the actuating member both for the make contacts and the break contacts is constituted by toothed members having constant tooth spacing, where the teeth are removed in all places where no contact actuation shall take place, whereby each contact can be made a make contact or a break contact, alternatively, in dependence on the point of actuation of the tooth on the contact springs. Thereby an extremely simple process of production is obtained, in that the actuating members may be produced in long lengths which are cut off, eventually broken off, into suitable lengths, the teeth being broken off according to directions given.

In another embodiment of the invention, the actuating members of the make contacts as well as of the break contacts consist of rows of small rollers on two shafts, and in the places where no contact actuation shall take place, provision is made of spacing rollers having such small diameter that in no position of the armatures they touch.

the contact springs whereby make or break contact is obtained in dependence on the point of actuation of the rollers on the contact springs. In this instance, principally uniform actuating members for the make and break contacts are likewise concerned, since it is only the different placing of the members on the two shafts which is decisive for the production of one or the other type of contact.

In a further expedient, embodiment according to the invention, the actuating members for the make contacts as well as the break contacts consist of small tubes having uneven wall thickness on two opposed sides and being assembled on a rod. Dependent on the position of the tube the actuated contact establishes make or break contact.

If the telecommunication circuit comprises a relay selector, it is, according to the invention, expedient that the multiple contacts with their associated conductors on the printed plate change numerical sequence at every second contact group or selector unit witha view to making multiple connections possible without crossing of conductors. The contacts of two neighboring units may thereby be directly interconnected by means of conductors situated on one side of the carrier plate, while the connections from each of the contacts of these two units to one each of the two subsequent units are placed on the other side of the plate. If the contacts are designed as contact rivets, these establish directly the necessary connection between the conductors on either side of the carrier plate, and in the case where no contact rivets are used but e.g. the contacts are plated on the conductors, or the conductors are directly used as contact-establish ing elements, the connection may be made round the edge of the plate. In both cases, separate connecting members, e.g., rivets or holes with a conductive material for the purpose of establishing contact between the conductors on either side of the plate, are avoided.

According to the invention, conductors on the printed plate may form common leads for the relay selector, while its individual multiple contacts consist of springs, but it is also possible according to the invention to let the conductors on the printed plate form individual contacts while contact springs form common leads.

In a particular embodiment of the telecommunication circuit according to the invention having a relay selector, there is a maneuvering member at each cross point, i.e. at the point of contact between the common lead and the individual multiple contact. The use of the separate maneuvering member affords advantages, in that the mounting and the connection thereof may be effected in a very simple manner as a consequence of all of the points of contact being placed on a'plane carrier, and this further involves the advantage that the bar mechanism otherwise used in the known relay selectors may be dispended with, that a great coupling speed is obtained, and that at any rate within certain limits the choice as to the size of the selector unit is free.

In this case it is possible by using two carrier plates with printed circuits on top of each other to double the capacity of the selector. In such case, two additional driving'systems may be used for establishing the connection to one or the other plate. Further, in such case, a common driving system is used at corresponding cross points on the two plates.

Accordingto the invention, it is particularly expedient that the individual multiple contacts, the multiple connections, and the common leads are lying in parallel planes, because by so doing an extremely simple construction is obtained.

In the following, the invention is explained in detail with reference to the drawing, where FIG. 1 shows diagrammatically part of an embodiment of the telecommunication circuit according to the invention in the form of a carrier plate having a printed circuit with fixed and movable relay contacts, of which 4 a part just as the driving systems associated with the relays have been left out for the sake of clarity,

FIG. 2 shows the embodiment of FIG. 1 as viewed in section at right angles to the plane of FIG. 1 parallel to the contact springs shown therein and with a driving system for a relay,

FIG. 3 shows a modified embodiment of the relay portion of the circuit in the same sectional view as FIG. 2,

FIG. 4 shows part of a modified embodiment of the circuit according to the invention having two carrier plates in the same sectional view as FIGS. 2 and 3,

FIG. 5 shows one of the carrier plates shown in FIG. 4}

FIG. 6 shows an embodiment of the telecommunication circuit according to the invention in the form of a relay selector with the associated wiring multiple as viewed from the side,

FIG. 7 shows a modified embodiment of the relay, selector shown in FIG. 6,

FIG. 8 shows part of a carrier plate with contact springs for the relay selector shown in FIG. 7, and

FIG. 9 shows the carrier plate shown in FIG. 8 as viewed from the other side.

In FIG. 1, l designates a carrier plate of a printed circuit having a number of printed conductors 2, of which for the sake of clarity only a few are shown. Those of the conductors 2 located at the side of the carrier plate shown in the figure are fully drawn whereas those located at the opposite side of the plate are shown in dotted lines. Connections between conductors at either side of the plate are according to the known and commonly used technique for printed circuits established through holes in the plate as indicated by 3, for example, by means of rivets or by conductive coatings on the side walls of the holes.

The conductors 2 constitute together with par-ts of relays, with which they are connected, the telecommunication circuit as used in various performances in the telecommunication plants.

On the printed conductors contact springs are secured, of which FIG. 1 illustrates two embodiments, namely, the contact springs 4 and the contact springs 4'. Ordinarily, only a single type of contact springs is used so that all of the contact springs in a given construction may by way of example by designed either as the contact springs 4 or as the contact springs 4'. The contact springs extend in parallel to each other across the carrier plate 1 with their free ends projecting outside one edge 5 of the plate 1.

The contact springs 4 or 4, of which one is shown in sideview in FIG. 2, are each provided with a contact 6', e.g. a contact rivet, and the conductor on the printed circuit associated with each of these contact springs, i.e. the conductor with which the contact spring concerned shall be able to make or break a connection, is in the vicinity of the edge 5 of the plate 1 designed with in creased width, as will be seen in FIG. 1 with the designation 7 on some conductors, where the associated contact springs have been removed for the sake of clarity.

On these extended parts 7 there may be plated a special contact material, or a contact may be riveted or welded on to said parts, but it is also possible, if desired, to use; the extended part proper of the printed conductor as a. contact and, if so, a precious metal should be used for the conductors.

Thus, each contact 6 forms together with the associated. contact part 7 on the printed circuit a set of contacts, and a certain number of such con-tact sets placed side by side constitute a contact system for a rela the contact springs 4 concerned being operated by a common driving,

system.

FIG. 2 shows such driving system in the form of a relay magnet 8 with associated armature 9 which by means of an angular piece 10 and an insulating interme-' diate layer is in a manner not shown secured to the carrier plate 1 on the same side as that where the contact springs are situated.

-on the edge 14 or a tooth on the edge 15.

From FIG. 2 it will be seen that the contact springs 4 are provided with a bent-out lug 12 at a distance from the free end.

On the armature 9 there is secured a driving member 13 of insulating material. The length of this member, i.e., the dimension at right angles to the plane of FIG. 2, is dependent on the number of contact sets associated with the relay concerned.

The driving member 13 has two operating edges, namely, an edge 14 projecting inwardly over the free ends of the contact springs 4, and an edge 15 projecting inwardly over the said lugs 12 of the contact springs. The two edges 14 and 15 are toothed so that there is a tooth opposite each contact spring, and they are so designed that they may easily be broken 011. During the process of manufacture, a breaking-oft of the tooth is eitected so as to leave opposite each contact spring either a tooth It will be seen that a contact set will in the first case work as a break contact and in the second case as a make contact and, consequently, the design of the contact springs 4 is quite independent of whether they are to be used for a make contact or a break contact, for which reason the two diiferent embodiments may be made completely alike. This involves considerable advantages with respect to manufacture. By way of example, the assembling of the springs on the printed wiring may be effected in the way that a certain number of contact springs, eg all contact springs for one and the same carrier plate, are made in one piece with a material strip at the end, so that all of the contact springs as a constructive unit may be brought in place in relation to the printed circuit and the individual contact springs are secured to the respective leads by an appropriate soldering process, whereupon the said material strip is cut off. Of the two embodiments of the contact springs shown in FIG. 4, contact springs 4 are soldered to printed conductors on the side of the plate 1 where the springs are situated, whereas the contact springs 4' with bent ends are extended through apertures in the plate 1 and connected with conductors situated on the other side of the plate.

In FIG. 2, a lead 16 is shown which connects the winding of the magnet 8 with one of the conductors of the printed circuit. In the embodiment shown, the connection is provided by means of a soldering lug 17, which is shown in FIG. 1. The connection may by way of example also be provided by means of soldering or riveting directly to the conductor concerned.

The circuit in question may, for example, be connected to a rack cable by means of a flat multiple plug of known type. For this purpose, conductors on the printed circuit in the embodiment shown have been extended out to the end-edge 18 of the plate 1, where the conductors are made wider and for the purpose of securing a reliable contact, taken round the edge and on to the other side of the plate so as to obtain a double-sided contact.

FIG. 3 illustrates an embodiment which as far as the placing of the driving system in relation to the carrier plate 1 is concerned, corresponds to that shown in FIG. 2, but the contact springs of the relay, which in FIG. 3 is designated by 26, is in this embodiment a wire spring,

one end of which is secured to a conductor on the carrier plate 1, while a bending 27 in the vicinity of the other end serves as a carrier of a contact. The relay is provided with two sets of actuating members 23 and 29, of which the former are operative when break contacts are concerned, and the latter when make contacts are concerned.

From the form of contact springs shown in FIG. 1 it will be seen that double contacts are used as is nowadays nearly always the case within the field of telephone technique. Such double contact may also be obtained in the case of wire springs as shown in FIG. 3 by using two alike interconnected wire springs placed closely side by side.

In FIGS. 4 and 5 there is shown part of a circuit according to the invention, where two

carrier plates

30 and 31 having printed circuits are used. One of these carrier plates is shown in FIG. 5.

On this carrier plate 30 there are a number of printed conductors 32 and a row of contact springs 33. These contact springs are, however, not as, is the case with the embodiments described above, separate members which in one way or the other are connected with the circuit, but they are directly constituted by narrow fingers produced at the edge of each plate, for example, by punching the spaces between the lugs so that each contact spring extends directly from the carrier plate as an integral part of the same, and likewise the printed conductors continue directly on the contact springs formed by the carrier plate. Out of regard to mechanical causes, namely, with a view tothe spring rigidity, as well as to the arrangement of leads, it may be expedient that the conductive coating is retained or placed on both sides of the contact springs 33.

In the case that the contact springs 33 are to constitute the movable contact springs, the carrier plate 31 in FIG. 4 may be designed with contacts in a manner corresponding to the one indicated in connection with FIGS. 1 and 2, but it is also possible to design the carrier plate 31 with punched lugs for forming the contact springs in the same manner as the carrier plate 30, as shown in FIG. 5.

In the embodiment shown in FIG. 4, the carrier plate 31 is supposed to be designed with contact springs 34 like the carrier plate 30 but, as will be seen from the figure, somewhat shorter than the contact springs 33. The required spring tension is provided by the two

plates

30 and 31 being fixed under a certain angle with a view to obtaining pressure opposite the direction of movement of the armature.

The contact springs 33 and 34 are supported by the flanges of a U-shaped bar, and the contact actuation is obtained by means of an actuating lug 36 secured to the armature 9 of the relay. There is such an actuating lug 36 for each contact set in the relay, and by bending of the lugs is determined whether the con-tact set concerned is to form a make contact or a break contact.

In the figure there is shown a make contact in that the lug 36 will actuate the contact spring in the direction towards the contact spring 33 by armature attraction. A break contact is obtained by the actuating lug 36 being bent forwardly so as to pass freely during the armature movement by the end of the contact spring 34 whereby an actuation of the contact spring 33- away from the contact spring 34 will take place.

By this embodiment the advantage is obtained that one avoids connecting contact springs with the carrier plate, because the contact springs are integral with said plate, and this advantage is obtained without the necessity of using two series-connected contact sets.

In the following some embodiments will be described of the telecommunication circuit according to the invention comprising relay selectors.

FIG. 6 shows in side-view such circuit, namely, a 20- line selector unit comprising 10 double contact units 40 designed with two

carrier plates

41 and 42 with mulitple conductors and relay contacts designed, for example, as indicated in connection with one of the embodiments described above, and so that each plate is common 'for one of all of the double contact units.

Of the units, mainly their contact actuating members are shown in end-view. Each double unit has its contact actuating member and associated driving member, e.g., a relay magnet, and for the sake of simplicity the figure only shows a few marked '43.

The movable contacts associated with the plate 41 are marked a, b, c, and d. Corresponding contacts for the carrier plate 42 are provided, but they cannot be seen in the figure.

The connection to one or the other of the two

plates

41 and 42 is established by means of two additional contact units 44.

As Will be seen in the figure, the sequence of the contacts of two neighbouring units are reversed in relation to each other, the connection of corresponding contacts of two units may, therefore, be provided all on the same side of the plate without being crossed. The connection to the subsequent unit may then in a corresponding manner be placed on the other side of the plate and so on, whereby an extremely simple arrangement of leads is obtained. If contact rivets are used, they may as well serve for establishing connection between the conductors on the two sides of the plate. Otherwise, the connection between conductors on the two sides of the plate may be established over the edge of the plate.

FIGS. 79 show by way of example part of an embodiment of a relay selector built-up according to a principle similar to that indicated in FIG. 6 and comprising movable contact springs designed as the embodiment shown in FIG. 5.

FIG. 7 shows two

carrier plates

51 and 52. placed one above the other at some distance from each other in the same manner as the

plates

41 and 42 in FIG. 6. These

plates

51 and 52 bear printed circuits with contacts along their edges shown at the left-hand side of the figure, which contacts co-operate with movable contacts designed as described in connection with FIG. 5, the said movable contact springs 53 and 54 being made by punching carrier plates having a printed circuit. FIGS. 8 and 9 are respectively a top-view and a bottom-view of part of the Contact springs 53 which are made integral with the carrier plate 55 having printed conductors extending unbrokenly from one contact spring to another over the nonsplit part of the carrier plate. The contacts in a selector unit are marked a, b, c, and d, and it will be seen that, like indicated in connection with FIG. 6, they lie in reversed sequence in two neighbouring units, the corresponding contacts of which are thus connected Without crossing of the conductors, and each of said units are correspondingly connected with a subsequent unit on the other side of the plate.

I claim:

1. A telecommunication circuit comprising a number of relays having fixed relay contacts and movable relay contacts, connecting leads, a carrier plate on which said fixed relay contacts and said leads are positioned as printed wirings, said movable contacts :being fixed connected with conductors of printed wirings, the actuating members for the make contacts as well as :for the break contacts comprising a row of small rollers on two shafts, the rollers on one of said shafts engaging only contact springs of make contacts, the rollers of the other of said shafts engaging only contact springs of break contacts.

2. A telecommunication circuit comprising a number of relays having fixed relay contacts and movable relay contacts, connecting leads, a carrier plate on which said fixed relay contacts and said leads are positioned as printed wirings, said movable contacts being fixed connected with conductors of printed wirings, the actuating members for the make contacts as well as for the break contacts comprising small tubes having uneven wall thicknesses on two opposed sides, said tubes being assembled on a rod, some of said tubes facing the springs of make contacts with one of said opposed sides, the other of said tubes facing the springs of break contacts with the other of said two opposed sides.

3; A telecommunication circuit comprising a number of relays having fixed relay contacts and movable relay contacts, connecting leads, a carrier plate on which said fixed relay contacts and said leads are positioned as printed wirings, said movable contacts being constituted by conductors of printed wirings, the actuating members for the make contacts as well as the break contacts comprising a row of small rollers on two shafts, the rollers on one of said shafts engaging only contact springs of make contacts, the rollers on the other of said shafts engaging only contact springs of break contacts.

4. A telecommunication circuit comprising a number of relays having fixed relay contacts and movable relay contacts, connecting leads, a carrier plate on which said fixed relay contacts and said leads are positioned as printed wirings, said movable contacts being constituted by conductors of printed wirings, the actuating members for the make contacts as well as for the break contacts comprising small tubes having uneven wall thicknesses on two opposed sides, said tubes being assembled on a rod, some of said tubes facing the springs of make contacts with one of said two opposed sides, the other of said tubes facing the springs of break contacts with the other of said two opposed sides.

5. A telecommunication circuit comprising a relay selector, groups of fixed multiple relay contacts, movable relay contacts, a carrier plate on which said fixed relay contacts and connecting leads associated with said fixed contacts are positioned as printed wirings, said movable contacts being constituted by conductors of printed wirings, each one of said multiple relay cont-acts in one of said groups corresponding to one of said multiple relay contacts in each other one of said groups, corresponding contacts being disposed in same sequence in each of said groups but in opposite directions of sequence in each two adjacent ones of said groups, two adjacent contacts belonging to each one of two adjacent groups being corresponding contacts.

6. A telecommunication circuit comprising a relay selector, groups of movable multiple relay contacts, fixed relay contacts, a carrier plate on which said fixed relay contacts and connecting leads associated with said fixed contacts are positioned as printed wirings, said movable contacts being constituted by conductors of printed wirings, each one of said multiple relay contacts in one of said groups corresponding to one of said multiple relay contacts in each other one of said groups, corresponding contacts being disposed in same sequence in each of said groups but in opposite directions of sequence in each two adjacent ones of said groups, two adjacent contacts .belonging to each one of two adjacent groups being corresponding contacts. 7

7. A telecommunication circuit comprising a relay selector, fixed multiple relay contacts with associated multiple leads, movable relay contacts with associated common leads, a carrier plate on which said fixed relay contacts and their said associated leads are positioned as printed wirings, said movable contacts and their said associated lead being fixed connected with conductors of printed wirings, eachone of said multiple relay contacts in one of said groups corresponding to one of said multiple relay contacts in each other one of said groups, corresponding contacts being disposed in same sequence in each of said groups but in opposite directions of sequence in each two adjacent ones of said groups, two adjacent contacts belonging to each one of two adjacent groups being corresponding contacts.

8. A telecommunication circuit comprising a relay selector, movable multiple relay contacts with associated multiple leads, fixed relay contacts with associated common leads, a carrier plate on which said fixed relay contacts and their said associated leads are positioned as printed wirings, said movable contacts and their said associated leads being fixed connected with conductors of printed wirings, each one of said multiple relay contacts in one of said groups corresponding to one of said multiple relay contacts in each other one of said groups, corresponding contacts being disposed in same sequence in each of said groups but in opposite directions of sequence in each two adjacent ones of said groups, two adjacent contacts belonging to each one of two adjacent groups being corresponding contacts.

9. A telecommunication circuit comprising a relay selector, groups of fixed multiple relay contacts, movable relay contacts, a carrier plate on which said fixed relay contacts and connecting leads associated with said fixed contacts are positioned as printed wirings, said movable contacts being constituted by conductors of printed wirings, each one of said multiple relay contacts in one of 5 said groups corresponding to one of said multiple relay contacts in each other one of said groups, corresponding contacts being disposed in same sequence in each of said groups 'but in opposite directions of sequence in each two adjacent ones of said groups, two adjacent contacts belonging to each one of two adjacent groups being corresponding contacts.

10. A telecommunication circuit comprising a relay selector, groups of movable multiple relay contacts, fixed relay contacts, a carrier plate on which said fixed relay contacts and connecting leads associated with said fixed cont-acts are positioned as printed wirings, said movable contacts being constituted by conductors of printed wirrings, each one of said multiple relay contacts in one of said groups corresponding to one of said multiple relay contacts in each other one of said groups, corresponding contacts being disposed in same sequence in each of said groups but in opposite directions of sequence in each two adjacent ones of said groups, two adjacent contacts belonging to each one of two adjacent groups being corresponding contacts.

References Cited in the file of this patent UNITED STATES PATENTS 1,133,787 Babcock Mar. 30, 1915 2,410,136 Vincent Oct. 29, 1946 2,454,060 Hegy Nov. 16, 1948 2,616,994 Luhn Nov. 4, 1952 2,682,643 T hias June 29, 1954 2,790,875 Bancroft Apr. 30, 1957 2,800,552 Durant July 23, *1957 2,853,564 Gahagan Sept. 23, 1958 2,853,565 Arthur et al. Sept. 23, 1958 2,866,030 Wir-th Dec. 23, 1958 2,906,838 Deighton Sept. 29, 1959 2,931,871 Dowds Apr. 5, 1960 FOREIGN PATENTS 762,999 Great Britain Dec. 5,, 1956

Claims

1. A TELECOMMUNICATION CIRCUIT COMPRISING A NUMBER OF RELAYS HAVING FIXED RELAY CONTACTS AND MOVABLE RELAY CONTACTS, CONNECTING LEADS, A CARRIER PLATE ON WHICH SAID FIXED RELAY CONTACTS AND SAID LEADS ARE POSITIONED AS PRINTED WIRINGS, SAID MOVABLE CONTACTS BEING FIXED CONNECTED WITH CONDUCTORS OF PRINTED WIRINGS, THE ACTUATING MEMBERS FOR THE MAKE CONTACTS AS WELL AS FOR THE BREAK CONTACTS COMPRISING A ROW OF SMALL ROLLERS ON TWO SHAFTS, THE ROLLERS ON ONE OF SAID SHAFTS ENGAGING ONLY CONTACT SPRINGS OF MAKE CONTACTS, THE ROLLERS OF THE OTHER OF SAID SHAFTS ENGAGING ONLY CONTACT SPRINGS OF BREAK CONTACTS.