US1226184A - Electrical selector. - Google Patents

Description

L. C. BYGRAVE.

ELECTRICAL SELECTOR.

APPLICATION FILED FEB-8.1916.

1,226, 1 84. Patented May 15, 1917;

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IMF- M L 1.1 1.4 L. 85; liar; I l 1 l r Inveniarr UNITED STATES PATENT OFFICE.

LEONARD CHARLES BYGRAVE, OF LONDON, ENGLAND, ASSIGNOR TO THE RELAY AUTOMATIC TELEPHONE COMPANY, LIMITED, 01 LONDON, ENGLAND.

ELECTRICAL SELECTOR.

To all whom it may concern:

Be it known that I, LEONARD CHARLES BY- GRAVE, a subject of the King of Great Brit'- ain, residing at Marconi House, Strand, London, England, have invented new and useful Improvements in Electrical Selectors, of which the following is a specification.

The invention relates to electrical selec tors or impulse responders consisting of relays which are energized in succession to select a certain circuit. The principal objects of the invention are to simplify the circuits of the selector and to reduce the number of relays required for a given number of selective positions.

The invention is illustrated panying drawing. of the invention having one switching relay for each selective position and Fig. 2 shows a selector in which the number of switching relays is less than the number of selectable lines.

by the accomrelay A. The selective impulses are sent over an impulse wire W from-an impulse transmitter, here represented by a key K.

A release key K controlling the locking circuits of the relays R, is closedv before the impulses are sent.

Upon the first impulse being sent, A is energized over a circuit extending through back contacts B of all relays R. A, upon operating, connects itself through its contact C directly to W and closes at its contact D the circuit of the first switching rei lay R which cuts itself in a locking circuit through its contact E and a contact F on the second relay R and prepares the circuit of the latter by closing contact G. \Vhen the first impulse ceases A denergizes and as its operating circuit is now open at contact B of relay R, the second impulse does not affect A, but operates the second relay R over contact B of A, contact Gr of relay R and .contact H of relay R RelayR. locks up over a circuit similar to that of relay R and prepares the circuit of relay R by closing its contact G. At the same time the locking circuit of the first switching relay is switched over to the impulse wire W at contact L. In consequence thereof relay R is denergized upon the cessation of the second impulse. In a simi- Speciflcation of Letters Patent.

Figure 1 shows one form The selector shown in Fig. 1 normally Patented May 15, 1917.

Application flied February 8, 1916. Serial No. 76,955.

lar manner the third impulse causes the operation of R and the deenergization of R and so on.

A relay, once deenergized, is evidently not renergized during the same setting period. The slector is restored to normal position by opening. the key K The selectable circuits, numbered 1 to 6, and here shown as single wire circuits, are connected to front gontacts of the corresponding switching reays.

I The selector shown in Fig. 2 consists of seven relays only, but may nevertheless be usedto select .any of ten circuits numbered 1 to 10. The circuits of the first six relays are mainly the same as in Fig. 1. there being five switching relays R. The seventh relay DR is a differentiating relay, operated bythe sixth impulse to switch the impulse circuit back to the starting end of the selector.

The first five impulses operate the selec-v tor in the manner iust described.

The sixth impulse energizes relay DR, which looks itself over its contact E and remains energized until the selector is restored to normal position. When the sixth impulse ceases, relay R denergizes and connects W over the back contacts B of all relays R to relay A. The selector is thereafter operated as before from the starting end by the seventh and following impulses.

The selectable circuits are divided in the manner shown in the drawing into two groups numbered 1 to 5 and 6 to 10 respectively, a circuit of the first group being connected up over a back contact of DR, while a circuit of the second group is connected up over a front contact thereof.

It appears from the above description that after six impulses have been sent, the differentiating relay DR only remains energized, and the sixth circuit is then connected up over back contacts of all relays R and front contact of DR.

A selector according to this invention, may be used for selecting circuits of any kind, but is particularly adapted for automatic and semi-automatic telephone systems. In such systems, for instance, it may be employed individually with each talking circuit to hold up a talking connection which it has established, or it may be'used in common by a plurality of talking lines and merely select and complete operating circuits for relays which make and hold up the connection; or it may be operated by a first series of impulses to select a group of lines and then by a second series of impulses to select a particular line of that group and to uphold the connection with said lines. It may also be used in combination with operators key-sets in semi-automatic systems to' control the transmission of current impulses, in which case the selector acts in known manner as a counting device to permit a certain number of impulses to be sent to the selectors of the exchange.

\Vhat I claim is 1. A selector comprising a series of switching relays, an impulse circuit for energizing the relays in succession and means for deenergizing a previously energized relay on the interruption of the impulse energizing the next relay.

2. A selector comprising a series of switching relays, an impulse circuit for energizin the relays in succession, means whereby eac relay on operating prepares the circuit of the next and means whereby each relay on deenergizing extends the impulse circuit to the next relay but one.

3. In an electrical selector, the combination of a starting relay, a plurality of switching relays, an impulse wire, means for transmitting electrical impulses to such wire, a back contact of each switching relay connected to a spring of the next succeeding relay, all such back contacts and springs being normally connected in series with the winding of the starting relay, a front contact of each switching relay being normally connected to the winding of the next succeeding relay, one of the springs of such next relay being adapted to break such connection and being connected to a front contact of the succeeding relay, springs of the relays connected to the impulse Wire and adapted to cooperate with the last mentioned contacts and means for restoring the relays to normal.

l. A selector comprising a series of switching relays, an impulse circuit for energizing the relays in succession, means whereby each relay after having been operated is deenergized on the interruption of the impulse energizing the next relay, said means com prising a holding circuit for each relay and means for opening such circuit on the cessation of the impulse succeeding the impulse which caused such relay to be energized.

5. A selector comprising a series of switching relays, an impulse circuit for energizing the relays in succession, means whereby each relay, after having been operated, is deenergizecl' on the interruption of the impulse energizing the next relay, said means comprising a holding circuit for each relay and means for branching such circuit to the impulse circuit on the operation of the next relay.

6. A selector comprising a series of switching relays, a number of selective lines controlled by said relays, an impulse circuit for energizing the relays in succession and means whereby the selector is automatically reset after it has been set to a fixed selective position.

7. A selector comprising a series of switching relays, a number of selective lines controlled. by said relays and arranged in groups, an impulse circuit for energizing the relays in succession and means whereby, after the selector has been set to a fixed selective position, a new group of selective lines is automatically switched into selective connection.

8. A selector comprising a series of switching relays, a number of selective lines controlled by said relays, an impulse circuit for energizing the relays in succession, means whereby each relay, after having been operated, is deenergized on the interruption of the impulse energizing the next relay and a differentiating relay operating, after the selector has been set to a fixed selective position, to switch the impulse circuit back to the first relay of the series.

LEONARD CHARLES BYGRAVE.

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