US3101395A - Cordless switchboard - Google Patents

Cordless switchboard Download PDF

Info

Publication number
US3101395A
US3101395A US813178A US81317859A US3101395A US 3101395 A US3101395 A US 3101395A US 813178 A US813178 A US 813178A US 81317859 A US81317859 A US 81317859A US 3101395 A US3101395 A US 3101395A
Authority
US
United States
Prior art keywords
contact
extension
button
contacts
switchboard
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US813178A
Other languages
English (en)
Inventor
Engqvist Erik Isidor
Adenstedt John Helge Willy
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Application granted granted Critical
Publication of US3101395A publication Critical patent/US3101395A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching

Definitions

  • the present invention refers to ⁇ a cordless switchboard, ie. a switchboard, at which all the connect-ions between the extensions connected to the switchboard are established by the operation of push buttons or keys only.
  • a ⁇ group of keys is provided for such extension and these groups yare for the sake of clearness yarranged in parallel rows.
  • corresponding keys have the same function so that, provided a certain key inone row in operated position connects a cord circuit to an extension assigned to this row, a corresponding key of another row in operated position connects the same cord circuit to the extension of this latter row. r[he two extensions are thus communicated when both keys simultaneously are operated.
  • Incoming exchange lines may be terminated in similar key rows as used for the extensions, whereby connections to these lines are treated by means of normal cord circuits, or these exchange lines may be connected to special cord circuits, which in this case are not to be used for interconnecting the extensions.
  • the accessibility for maintenance work is rather bad.
  • the vkey has [to be detached in order to make the springs accessible, whereby the risk ⁇ arises of breaking wires connected to the key.
  • One object of the invention is to provide Ia simple cord less switchboard in which each contact means includes only a yfew contact springs and 4in which the wiring is reduced as far as possible.
  • Another Iobject is to provide a switchboard in which the contact springs are easily accessible ⁇ for adjustment without having to -detach the contact means.
  • An additional object of the invention is to provide la switchboard having an extremely simple operators switching procedure.
  • each group of contact means arranged for connecting the necessary auxiliary circuits, such as cord circuits, operators circuit etc., to an extension, is provided with a mechanical Ablock-ing member, which is yieldably held in a blocking position 'where it retains any contact means yof the group brought to active position, said blocking member at operation of any other contact means of the group being momentarily removed from the blocking position, soi that the contact means, retained up to that moment, is liberated and by its resiliency brought back to inactive position.
  • FIIG. 1 is a schematic representation of the contact arrangement of the switchboard, including two vertical pushbutton strips with locking b-ars, joined together by horizontal contact-carrying plates;
  • FIG. 2 is ya diagram showing the principal electrical circuits of the switchboard in a preferred layout, all the 3,l0
  • FIG. 3 is a diagram showing the circuit of ian extension line in ⁇ an alternative design of the switchboard, all the contacts of the extension line circuit being connected in parallel.
  • Thek contact means are larranged in 'a supporting iirame consisting on the one hand of Ia number of plane, parallel land equidistant push button strips 11 and on the other hand of contact plates 12 of insulating material that are placed at right angles 'to the strips and are also parallel )and equidistant.
  • Eachr push button strip carries along the one edge a number of push buttons -13 which are normally kept in inactive position away from Ithe edge by means of individual springs (not shown on the ligure) yand that may be ldepressed against the spring fonce into a position, where the contact springs are actuated.
  • the push button endstur-ned inwards the strip are designed as two parallel bars 14 and 15, that are placed on each side of the strip, the bars being formed for actuating each a pair of contact springs.
  • a blocking bar 16 common to lall of the push buttons, is in a convenient way provided on the strip, which bar by means ot a spring (not shown) is held in a blocking position, in which any 'depressed button is retained.
  • the blocking bar is in the known way so
  • Two contact bars are xed in parallel relationship' on each side of the plate adjacent tot one olf the longitudinal .edges of the plate.
  • the movable contact springs are of equal size, 'are fixed to the opposite longitudinal ⁇
  • the edge carrying the contact springs is provided -with recesses tor said springs, of which recesses every second 19 is of 'a certain depth while the others 2i) are of a different depth. The difference of depth corresponds to the distance between the con-tact bars, so that the legs of the contact springsy on each one side of the contact plate with ⁇ their ends reach alternatively tol the one cont-act bar and to the other.
  • both are provided with slits 21 and 22.
  • the width of the slits 21 equals the thickness of the contact plates
  • the width of the slits 22 of the plate equalling the thickness of the contact strip.
  • the lengths of the slits as well as their location along the strip and the plate respectively are chosen in such a way that when assembling the strips and plates that their respective slit bottoms touch each other, and the inner endsy of the push buttons are brought to an adequate position for co-operation with the contact springs.
  • the contact springs of the different contact plates, each one with its legs are in Contact with equally placed contact springs on adjacent plates.
  • FIG. 2 shows a simplified diagram of ⁇ the switchboard. For the salie of simplicity only equipment for two extensions, one cord circuit and one exchange line, is shown on the drawing, whereas only those parts of the operators circuit that are necessary for explaining the principle of the invention are shown.
  • the switchboard is provided with one push button strip for each extension and with one for the operators circuit, the diagram of the gure including four push buttons TT, TS, TC and TA for each push bntton strip.
  • La and Lb indicate the connection points of the aand b-wire of the extension.
  • B is an indicator that serves as a signal means for calling and conclusion signals.
  • the extension line can be connected to the operators circuit, by means of the TS- button lto a cord circuit, by means of the TC-button -to the exchange line and by means of the 'TA-button to the v signal indicator.
  • Each push button actuates two contact spring pairs 2, 3 and 6, 7, all the contact spring pairs indicated by 2, 3 being located on one side of the strip while the contact pairs 6, '7 are on the other side.
  • a change relay TR indicates a feeding relay of the cord circuit
  • CL are connection points for an exchange line
  • CI a call indicator of said line.
  • the call indicator ⁇ Cl is connected in series with a condenser Cl, which can be short-circuited by means of a manually operable push button V.
  • DR is a holding coil for the exchange line and CRll is an auxiliary relay for connecting the holding coil.
  • CR is a supervisory relay that in order not to introduce an unnecessary attenuation in the exchange line is bridged by a condenser C2.
  • the contacts 3 and 2 of the 'TA-button are thereby closed and a circuit is formed from positive on TA through contacts 3, 2 of TA, TC and TS and contacts 3, 4 of TT to relay TR and negative, whereby said relay operates and connects the operators circuits to the contacts 5 and S of the button TT.
  • the b-wire of this extension is connected to the operators circuit while the a-wire is connected through the contacts '7, 8 of the same button TT and contacts 6, 7 of TS, TC and TA.
  • the operator presses a TS-button belonging to this extension and corresponding to a free cord circuit, whereby the TT-button of this extension is restored. Thereafter she presses the 'IT-button of the solicited extension, whereby lthis extension is connected to .the operators circuit. After having sent out a ringing signal, which is eiected by a ringing button (not shown) of the operators circuit, she oppresses the TS-button of the called extension, whereby the two extensions are connected together through contacts i 5, 6 and 7, 8 of their respective TS-buttons.
  • the feeding relay FR that is connected -to the contacts 5 and 8 of these buttons, is common to the two extensions.
  • the relay was operated through the loop of the calling subscriber, when the 'TS-button of this extension was oppressed, and is maintained operated until, ater conversation, the two subscribers have hung up their receivers. This having occurred the relay FR releases and connects current through its contact to the contacts ll and 2 of the two TS-buttons land from these through the contacts 3 and 2 of the respective rIT-buttons to the indicators B of both extensions, which are actuated and show conclusion signals.
  • ⁇ Current is then connected from the contacts of the relay through contacts 1, 2 of the lCR-buttort to the indicator of the extension, which shows conclusion signal.
  • the operator then presses the TA-button, whereby the rIC-button is restored yand the exchange connection disconnected.
  • the operator connects herself to the exchange line by pressing the TC-button of the operators circuit.
  • the operator sends a yringing sign-al to this extension in the same way as indicated Ibelow internal Calls and thereafter she presses the TC-button oi said extension.
  • a circuit is closed lfrom positive on the contacts 3, 2 of the TA-button of the exchange, through contacts 3, i of Ithe 'TC-button, the Winding of relay RCL the contacts l, Z of the TC-button of the operator, contacts 3, 2 of the TS- and "IT-buttons to negative.
  • Relay RCll operates and takes hoilding to negative on its own contact.
  • the holding coil DR is lsimultaneously connected across the exchange line, whereby this line is retained until the extension answers, so that the operator in the meantime is at liberty to handle other calls.
  • the supervisory yrelay CR operates and when this relay after termination of the call releases, current is connected t-o the indicator of the extension, which shows conclusion signal as described below outgoing exchange calls.
  • the operator then presses the rlTA-button of the extension, whereby the TC-button is liberated.
  • the relay CRl releases and the extension as well as ⁇ exchange line are free ttor new calls.
  • FIG. 3 shows a diagram'rfor 1an extension equipment in which the contact pairs referred to are connected in parallel.
  • a cordless manual switchboard 'for connecting local lines to trunk lines and local lines in pairs comprising, calling signal means for each local line, la plurality of push buttons for each local line, locking means releasably securing a single one of said push buttons in a depressed position and simultaneously releasinganother depress-ed push 'button in response to manual yactuation thereof, said one of said push buttons in ysaid depressed position connecting said calling signal means to the respective local line.
  • each movable leg of each contact spring in a normally inactive position is in contact with a leg of la contact spring located on an 'adjacent contact strip, whereby said'contact springs compose a series circuit along each l push Ibfutton strip from a contact spring on the uppermost contact strip to a conta-ct spring lon the lowermost contact strip through contact springs on intermediate 'contact strips.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Push-Button Switches (AREA)
  • Telephonic Communication Services (AREA)
  • Transceivers (AREA)
  • Telephone Set Structure (AREA)
US813178A 1958-05-23 1959-05-14 Cordless switchboard Expired - Lifetime US3101395A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE497858 1958-05-23

Publications (1)

Publication Number Publication Date
US3101395A true US3101395A (en) 1963-08-20

Family

ID=20265415

Family Applications (1)

Application Number Title Priority Date Filing Date
US813178A Expired - Lifetime US3101395A (en) 1958-05-23 1959-05-14 Cordless switchboard

Country Status (5)

Country Link
US (1) US3101395A (fr)
BE (1) BE578329A (fr)
DE (1) DE1138825B (fr)
FR (1) FR1224640A (fr)
GB (1) GB917398A (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2107158A (en) * 1937-02-26 1938-02-01 Bell Telephone Labor Inc Telephone system
US2559561A (en) * 1947-07-07 1951-07-03 Micha Louis Telephone switchboard
US2613281A (en) * 1948-12-30 1952-10-07 Micha Louis Cordless telephone switchboard with interlocks

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE176831C (fr) *
DE949241C (de) * 1951-02-10 1956-09-13 Allg Telefonfabrik G M B H Einrichtung fuer an Fernsprech-Reihenschaltgeraeten vorgesehene Seitenschalter
DE1008360B (de) * 1953-06-09 1957-05-16 Autophon Ag Einrichtung in Telephonteilnehmerstationen mit mehreren durchgehenden Amtsleitungen

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2107158A (en) * 1937-02-26 1938-02-01 Bell Telephone Labor Inc Telephone system
US2559561A (en) * 1947-07-07 1951-07-03 Micha Louis Telephone switchboard
US2613281A (en) * 1948-12-30 1952-10-07 Micha Louis Cordless telephone switchboard with interlocks

Also Published As

Publication number Publication date
DE1138825B (de) 1962-10-31
BE578329A (fr) 1959-08-17
GB917398A (en) 1963-02-06
FR1224640A (fr) 1960-06-24

Similar Documents

Publication Publication Date Title
US3101395A (en) Cordless switchboard
US2691066A (en) Automatic telephone system
GB550235A (en) Improvements in telephone systems
US2993095A (en) Private branch exchange telephone system involving a cordless type switchboard
US2969439A (en) Electric switching device
US3001027A (en) Private line transfer switching circuit
US2929881A (en) Terminal-per-station telephone partyline switching system
US2164731A (en) Telephone system
US1568039A (en) Telephone-exchange system
GB1437031A (en) House exchange telephone system
GB1471364A (en) Electronic telephone system
US3325602A (en) Multiple station access repertory dialing system
US2212216A (en) Telephone set
US3048662A (en) Pabx switching system
US2907832A (en) Crossbar relay private branch exchange telephone system
US3014989A (en) Incoming telephone call pabx restrictive service
US2541336A (en) Secretary's answering key cabinet
US3328533A (en) Direct key calling telephone station having binary converting means
US3137771A (en) Paging system
US2847512A (en) Secretarial answering system
US3033942A (en) Cordless switchboard
US1107143A (en) Telephone-exchange system.
US2848547A (en) Station-identifying call-recording telephone system
US2762864A (en) Automatic telephone system
US1942671A (en) Telephone system