US1506760A - Calling device - Google Patents

Description

Patented Sept. 2, 1924.

UNITED STATES PATENT OFFICE.

NOEL I-I. LYSONS, OF MONTREAL, QUEBEC, CANADA, ASSIGNOR T0 WESTERN ELECTRIC COMPANY, INCORPORATED, 0F NEW YORK, N. Y., A CORPORATION OF NEW,YORK.

CALLING DEVICE.

Application filed May 24, 1922. Serial No. 563,185.

To all whom t may conce/m:

Be it known that I, NOEL I-I. LrsoNs, a subject of the King of England, residing at Montreal, Province of Quebec, Canada, have invented certain new and useful Improvements in Calling Devices, of which the following is a full, clear, concise, and exact description.

This invention relates to calling devices and particularly to impulse transmitters employed in automatic and semi-automatic telephone systems for the purpose of controlling the operation of switching mechanism.

In automatic telephone systems it is necessary to allow a certain minimum time interval between the last impulse of a series sent by a calling device and the first impulse of the next series in order to permit the switch ing mechanism to distinguish between successive digits.` This interval must be of as long a duration as the maximum time required for the automatic hunting operation of the switches at the central ofiice. In the usual type of calling device, a period of delay, after the group of impulses for each digit is sent, is secured by reason of the necessity of resetting the device for the next digit. It has been found by experience, however, that this period is not always suficient, particularly when the resetting movement is small, as in the case of the lower digits.

The object of the invention is to provide an impulse transmitter with simple and ecient means for insuring the proper time interval between the transmission of successive series of impulses in order to prevent false connections from being made.

The invention provides means, such as an arm integral with the motor spring and controlled by the main shaft of the dial, for removing the impulse springs from the control of the interrupter mechanism after the required number of impulses has been transmitted and at a definite time interval before themechanism reaches its normal position. In the drawing, Fig. 1 is a front view of a calling device embodying the invention;

Fig. 2 is a rear view; Fig. 3 is a side View; n Figs. 4 to 8, inclusive, show in successive stages, the operation ofthe impulse springs of the calling device; and

Fig. 9 shows a modiiedarrangement of springs in a position corresponding to Fig. 4; and

Fig. 10 is a fragmentary view of a detail of the device. y

The dial plate or finger wheel 1 is fixed to a shaft 2 rotatablysupported in a base plate 24. A spring 25 serves as a motor spring for driving the shaft. On the under side of the dial plate 1 is secured a pawl 27 which is arranged to engage with the ratchet 28 carried by the gear member 5, which meshes with the pinion. 6. On the same shaft as the pinion 6 is the butterfly cam or interrupter 3 and the gear 7, the latter of which drives the governor 4. The relation of the pawl and ratchet 27 and 28 is such that when the finger wheel is revolved in a clockwise direction, referring to Fig. 1, the gear 5 is not rotated. When the finger wheel is subsequently released, it is returned to its normal position by means of the motor spring 25, and during its return movement, the pawl 27 engages ratchet 28 and, therefore, causes the rotation of the interrupter 3 and the governor 4, all as disclosed more in detail in U. S. Patent No. 1,279,352 of Septemberl 17, 1918, to A.. E. Keith.

On the interrupter cam shaft 'is secured a. collar 30, having two diametrically disposed notches or recesses 31; mounted on the plate 24 is a bent leaf spring 32 with lits free end arranged to engage one of the notches 31 when the interrupter cam is in normal position; the position of the vspring is such that when the cam 3 and collar 30 rotate in a counter-clockwise direction (as viewed in Fig. 2),.the spring 32 is depressed and the collar30 rides Nover it, and if there is a tendency to rotate in the opposite direction, the side wall of one of the recesses 31 meets the end of the spring 32 and further movement is prevented.

Contact spring set 10, mounted on the rear of the base plate 24, comprises the springs 11, 14, 15, and 16. The arrangement of the springs is such that spring 14 tends to move toward spring 16 and makes contact therewith, and impulse spring 11 tends to move away from spring 15 and to bring its end 12 into the path of rotation of interrupter 3. However, when the finger wheel 1 is in normal position, as shown'in Fig. 1, finger 13 carried on the inner end of the shaft 2, bears 'upon ythe upper surface 14" near the free end of the spring 16 and'holds it "lawa'yfrom spring 16 and lagainst spring 11,"`whi`chin`-turn is'held against spring 15, making contact therewith and holding its outer end 12 out of the path of the interrupter 3. The arm 13, in the form shown in the drawings, is an insulated vextensin of, the motor spring 25. y l

1Iii-practice, the VContact'spring 15 will lbe connectedby a suitable conductor 44 to one side of fthe' "subscribers line, while lthe springs 11 and `l1'4, which aretied together, willbe conductively connected to the other side '40'through the subscriber@ receiver 41 and transmitter 42. Spring 16 will be lconducftiyely connectedfto the second side of thesubscribers line in'shunt of the 'receiver .41.- Therefore, whenth'e. springs are inthe position shown in Figsf4and 8 of the drawingfthel circuitwill be Closed through the subseribers telephone instruments.

llvllienv Jthe Isubscriber ydials 'the yfirst digit `by rotating thenger wheel in a clockwise directiomthe lvarm`13 will be moved inthe direetion'of the arrow, inFig. 4, and will, therefore, `after a short movement, release the spring 1,4,- which will thereupon rise and make Contact with spring 16, thereby shiuiting the sul'oscribers receiver during the dialing operation, as is common practice. Thev release 'of spring 14 also results in 'the -partial release of spring 11. Spring 11, however, is` permitted to move only a short distance `when it is stopped by the contact of its outer end 12 with a wing of the interrupter 3 This movement of springll is not sluiiicient f to breakits contactwith spring 15. As soon as thelinger wheelv is released and-starts. on its return movement,

the .interrupt-er '3` is rotated as Adescribed .above and intermittently releases and de- -presses the spring 11,-(Figs-6 and 7) vthus alternately breaking and making its contact with spring 15 and, therefore, sending outv impulses over the line and eiecting the selective Ioperation of a switching device at the Acentral eXchangein a well-known manner.

l i Since itis l'the ycustom of the callingsubscriber to immediately reset the dial, the second series of impulses is frequently begun before connection has been completed at the central exchange to a switch that is free,V toV respond to its impulses, withthe resultjthat there is an incorrect settingy of the switches.I In the present device, the dial plate 1, andthereforetheinterrupter 3, continue to-y rotate for a, substantial period,

when the required number yof impulses has tained during the entire rotation rofthe .in-

terrupter 3 and no impulses are sent over the line. As the dial continues to rotate, arm 13 moves invthe direction of the arrows shown in Figs. 7 VVand 8, and finally when the dial plate reaches its normal relation, the parts assume the position shown in'Fig. 8, which is the same as thatshownin'Fi'g; 4. rlhe dial will now'be reset'for the next series ofy impulses and the sequence Vof operations shown in Figs. '4to 8fwill'be repeated. There is, thus, added tothe interval re quired for resetting the rvdial ari-"interval equal to the time which is occupied fby'the dial in moving through an anglesuflicient to bring the interrupter 3 lto the position shown in Fig.' S. iThe length of this'period will depend upon the length'of bearing'surface '14"of`the spring 14. A period equivalent tofthat required for sending two'impulses has been found to give satisfactry results. y y y p The modification shown in ig. "9 is adapted to be usedwitha circuitsimilarto that shown in 'UQ S. VPatent LNo."1,353,612, September 21, l1920, to F- N. Reeves. Spring 15 willbe connected to'one side 43 of the line. VSpring 20 will vbe connected throughthe receiver`49 to the" same sideof vthe line. Springs 11 an'd 16, which'are electrically tied .'togetlier, will be connecte'd'to the other side ofthe line` through "the transmitter 46. Spring' 14I will be connected to said other side 45 of theline Yinshiint of the transmitterfl when thesubstation circ-uit' is yready'forI the calling Idevice to be operated. Spring 16 is adapted to cooperate withI spring 14 to close .a pathfalternate 'to the^path through spring f2() and the receiver. Spring 11 ispr'ovided with an insulatedlmember 22 to prevent electrical connection betweenfit and sprii1g`14. l

What is claimed is: n s y f 1. InI an impulse sending device,`a.inger wheel for setting said fd'evice, Contact springs, *an interrupter for said `contact springs, a motor yspring for operating-,said device, and means integral with said'mlotor spring for removing said contact springs from the control of' said interrupten' 2. In anaimp'ulse sending device, a linger wheel for setting said device, a plurality of contact springs, an -interrupterV in operative relation to one of said contact' springs, a motor spring, an arm integral withsaid motor spring in operative relation topan- "rac other of said Contact springs and controlled motor spring in operative relation to anby said finger Wheel for removing said other of said Contact springs and controlled 10 springs from the control of said interrupter. by said finger Wheel for removing said 3. In an impulse sending device, a finger springs from the control of said interruptor` Wheel for setting said device, a plurality of ln Witness whereof, I hereunto subscribe Contact springs, an interrupter in operative my name this seventeenth day of May,. relation to one of said Contact springs, a A. D. 1922. motor spring, an arm integral with. said NOEL H. LYSONS.

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