US1551722A - Telephone signal device - Google Patents

Description

Sept. 1; 1925.

F. H. N. WOYHLERS TELEPHONE SIGNAL'DEVICE Filed April 14. 1921 2 Sheets-Sheet l INVEN TOR.

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sept. 1'; 1925. I 1,551,722

A E.' H. N. woHLERs TELEPHONE S IGNAL DEVICE Filed April `14. 1921 2 Sheets-Shea?. 2

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Patented Sept. 1, 1925.

UNITED. STATES PATENT oF'FflcE.

FRIEDRICH H. N. WOHLEB/Sl OF JAMAICA, NEW YORK, ASSIGNOR TO DICTOGRAPH PRODUCTS CORPORATION, A CORPORATION OF VIRGINIA.

TELEPHONE SIGNAL DEVICE.

Application med April 14,1921. serial No. 461,282.

i nection with intercommunicating telephones.

In various telephone and similar systems, certain stations may be rovided with a plurality of visual signed/devices, each corresponding to a different distant station, andwith a buzzeror audible signal device and circuit which may be controlled singly or in common by alll of the visual signal devices, to be rendered active whenever any visual signal device is shifted to a full indicating position. This shifting of the device is usually accomplished by means of an electromagnet which is energized by the closin of a circuit thereto from the corresponding distant station. The circuit of the electromagnet is opened to permit of the return of the visual signal to its normal position whenever the calling party discontinues the calling attempt or the called party connects his instruments with the calling party. It often happens that the party at the called station is absent at .the time the call is made and upon his returnl desires toA know whether or not attemptsto communicate with him have been made during his absence, and if so, the identification of the calling station. It has been proposed to furnish such a notification of unanswered calls by locking the visual indicators, when operated during a call, in their call indicating position, but where audible signals are controlled thereby and considerable delay occurs in the return of the called party the audible signal batteries soon run down and have to be replaced. The continued op eration of the audible signal is also often objectionable to other nearby parties.

An object of the invention is to provide a switchboard construction for intercommunicatin telephone systems which will visually an audlbly indicate all calls and identify the calling station, which will indicate to the called partythat an ineffectual attempt to commumcate with him has been made by another station, and identify that station, which will accomplish these. results with a minimum of deterioration of batteries or consumption of energy, and in which the indicator will be automatically restored to normal non-indicating position by the act of calling the prior calling station from the prior called station. A further object is to provide a construction of this kind and for this Vpurpose which is simple, eficient, reliable, inexpensive, and easily installed on existing switchboards withA a minimumo changes in existing constructions. Other objects and advantages will be apparent from" the following descriptions, and the novel features of my invention will be particularly pointed out in the claims. .l

In carrying my invention into practice I may provide a latch for each visual indicator for automatically preventing its complete return to non-indicating position, at the cessation of an unanswered call from a distant station, but permitting a return sufficient to open the circuit of the audible signal device, and also indicate by its position that an unanswered call was received. The

latch is arranged to be operated to release the visual in dicator upon an operation of the switch during the completion or breaking of the connections incident to the answering of the call, or duringa special releasing operation.

In the accompanying drawings:

Fig. l is a side elevation Yof a switch board uni constructed in accordance with my inven ion with the visual indicator in one indicating position;

Fig. 2. is a front elevationpf the same;

Fig. 3 is a side elevation of the same withv some of the parts in positions dii'erent from those of Fig. l;

Fig. 4 is a front elevation of the same; Fig. 5 is a side elevation of the samev with some of the parts in a still different position; y

Fig. 6 is a front elevation of the same; Fig. 7 is a side elevation of the same showing the positions of the parts, d'uring the receipt o a call;

.Fig. 8 is front elevation of the same, and

Fig. 9 is a wiring diagram.

In the illustrated embodiment, a frame unit l of a switchboard carries `upon its rear side an electromagnet or relay'2, and upon mounted a pivoted armature 5,which is responsive to the influence of the electromagnet. The armature carries a rigid arm 6, extending from one side thereof and along one side of the electromagnet toward the face plate 3. The frame 1 is provided on the l side abutting the face plate and opposite the window with a slot 7 into which the free end 8 of the arm is turned to form an indicating element. lVhenthe electromagnet is deenergized the indicating arm normally lies at the bottom of theA slot and holds the armature away from the electromagnet as illustrated in Figs. 5 and 6. When the electromagnet is energized, the armature will be attracted and carry the indicating end 8 of arm 6 toward the top of the slot and behind the window as illustrated in Figs. 7 and 8,which position of the arm 6 represents the full indicating position and visually notities the attendant'at that station that a certain station is calling. If the call is unanswered, a discontinuance of the call causes. a deenergization of the electromagnet 2 and the arm 6 falls. A bell crank pawl 9, pivoted tothe frame unit 1, is normally urged by gravity or a suitable -spring to rotation in a direction to bring one of its arms 9a below the indicating arm 8. The arm 9n is normally held by the arm 8 at one side thereof when arm 8 is .1n its lower non-indicating position. Upward movement ot the arm b during a call releases the pawl automatically and permits 1t to move to bring the arm 9 beneath the arm 8. Vhen the arm 8 falls it engages the end of the pawl and is held in an intermediate indicating position as illustrated in Figs. 1't0 4.

A switch key 10 is pivoted in the frame unit and extends through an aperture 11 in the' facev plate for manual operation. spring strip contact 12 is normally in contact with a spring contact'l for controlling the circuit to the electromagnet but `is shiftable by one of the cam rollers 14 on an ex* tension of the key out of engagement therewith and into engagement with a spring contact strip 15 controlling the talking circuit whenever the key is moved upwardly.A The free end of strip 12 is offset tangentially of a cam roller so that when the key is shifted upwardly, the strip 12 will be locked in engagement with strip 15 and will yieldingly Ahold the key in upper position as limited by a lug 16 of the key which engages with the face plate. Spring strips 17 extending over the cam rollers yieldingly limit downward movement of the key beyond its normal or straight out position, while a second lug 18 on the key by its engagement witlrthe face plate limits downward movement of the key. The strips 12 and 17 engage on opposite sides of the cam rollers 14, when the key is vin normal straight out position and yieldthe action of gravity is ordinarily sufficient. A,

Limited downward movement of the key beyond normal position,l as illustrated in Figs. 5 and 6 will force the free end of one of the strips 17 upwardly and through it carry the pawl to a position in which it releases the indicating arm. An arm 18a on the armature is adapted to move into engagement with a spring contact 19 carried by and insulated from the electromagnet when the armature has shifted the indicator to approximately its full indicating position. A battery 2O is connected by wire 2l to a buazer, or other suitable audible signal device 22. The buzzer is connected by a wire 23 with each of the contacts 19 carried by the electromagnets or relays 2, so that each pair of contacts 18a and 19 may complete the circuit through the bell independently of the' others. The contacts 19 are so disposed relative to arms 184 that when the arm Sgis held in an intermediate indicating position the contactsv 18 vand 19. of the corresponding electromagnet will be in an open circuit condition. The audible signal circuit is diagrammatically illustrated in Fig. 9, in which only portions of the other circuits are shown, the complete circuits being illustrated and described in the U. S. Patent No. 1,160,125.

In use let it be assumed that a call is received at the stationl C through a wire 2/1 from a distant station A, the key 10 at station CY being in normal position. The calling circuit includes contact strips 12 and 13 and. electromagnet 2 corresponding to station A. The energization of this electromagnet 2 moves its indicator to full indicating position and through contacts 18l1 and 19.closes the audible signal circuit to andibly call attention to the fact that another station is calling, the identification of the calling station being given by the raised indicating arm 8 corresponding to that station.

When a 'key 10 at station C correspondin to the visual signal then effective is operated llO i upwardly from the Fig. 1 to the'iFig. 3 position, the strip 12 will be separated from contact with strip 13 to open the circuit through the energized electromagnet 2 permitting the indicator to fall, and connect the wire 24 instead to the talking circuit with the distant station. The visual signal arm 8 thereupon drops but is held in an intermediate position by the'pawl or lever 9 which moved beneath the arm 8 when the latter was moved to its full indicating position by the energized electromagnet. In this intermediate position thd contacts 18a and 19 are separated and the buzzer circuit is open.y During the return movement of the key to its normal straight outposition at the conclusionof the conversation, the

' spring strip 12 usually imparts enough energy to the key to carry it against the upper strips 17 and shift pawl 9 to release the arm. The arm then drops to the bott-om of the slot 7 which is its normal position, as illustrated in Figs. 5 and 6. If the return of the keyfails to vrelease the arm 8 from the pawl, the key `can be slightly depressed as illustrated in Figs. 5 and 6 to force the pawl clockwise and K release the arm 8. The spring strip 17 will then return the key to Anormal straight out position when released.

It the call from station A is unanswered, the disconnection at station A at thelabandonment of the call will open the circuit to the energized yelectromagnet 2 and permit the indicator arm 8 to fall.- The pawl 9 will prevent a complete return of the arm 8 but will allow it to return far enough to open the audible signal circuit, by separat? ing the contacts 18a and 19` There will be no circuit iiowing through the system and the intermediate position of the indicator arm8 will visually indicate that an unanswered call was received. The yoperation of the vkey 10 in calling station A to answer the call willcause a complete release and return of the arm v8 as before. fThe pawl 9 )drops back at vone side of the arm 8 when the latter Ais released, so as to be ready to move beneath the arm when another call is received.

L :It will be obvious that various changes in the details and 'arrangements herein described and illustrated for the purpose of vexplaining the principle of -the invention, may be made within the principle and scope of the invention.

Lclaim: 1. A switchboard construction comprising an indicator movable between two indicatingpositions, remotely operable means for actuating the indicator from one position to the other, means adapt-ed to automatically prevent complete return of the indicator to initial position, but -permit return to an, intermediate indicating position, va switch device and means operative bythe switch device upon an operation thereof for releasing the indicator to permit of its complete return to its initial position.

'switch device, and means operable by the switch device as the latter is operated for releasing the element to permit of its complete return.

3. A switch board construction comprising an electromagnet normally included in a telephone circuit, an armature for the electromagnet and operable thereby, a visual indicator operable by the armature between two extreme indicating positions, an audible signal rendered active by the visual indicator when the latter has been shifted to one of its extreme positions by t e energization of the electromagnet, a device for preventing complete return of the indicator upon deenergization of the electromagnet but per. mitting return to an intermediate indicating position ',in which .the audible signal is inactive, a switch device for disconnecting the electromagnet 'from the circuit and operable upon said device to release the visual indicator and permit it to return completely to its Vother extreme indicating position.

4. A switchboard construction comprising an indicating member operable between two extreme indicating positions, means controlled from a telephone system for causing movement of the member from one of said positions to theother upon the receipt of a call from a station corresponding to said member, an audible signal device rendered other position, means operative upona movement of the member froml said one posi tion to the other for preventing complete` return of the member upon a cessation of the 'active by movement of the member to said y key held in normal position by said strips, a pivoted pawlv biased to rotation in one direction against one of the strips to bring an arm beneath the indicating member for preventing a complete returnot the latter to said one position but permitting a partial return, said pawl being operable to release -the member for complete return movement to said one position through the operation of the key to flex the strip. that is engaged by the pawl.

6. A switchboard construction comprising a frame unit, a face plate having a Window therein carried bythe unit, means carried by the frame responsive to an incoming call from a distant station for indicating the existence of the call including a member movable -behind the window from a normal position to another position when a call is being received and tending to return to normal position when the call ceases, an audible signal device controlled by the member. and rendered active when the latter is in said another position, switch mechanism for controlling a circuit to said distant Station, a pawlpivoted to the frame and biasscd to rotate to bring an arm thereof beneath the member when it moves from normal position to the other position and limit its return movement to an intermediate position in Which the audible device is inactive When the call ceases, and switch mechanism controlling a circuit to said distant station operable to shift the pawl to release the member for complete return to normal position.

In witness whereof, I hereunto subscribe my signature.

FRIEDRICH H. N. VOHLERS.

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