US2355349A - Signal impulse sending system - Google Patents

Description

Aug. 8, "1944. H, wHEELOCK ET AL 2,355,349

SIGNAL IMPULSE SENDING SYSTEM Filed June 21, 1940 s Sheets-Shed 1 I Z iche J. H. WHEELOCK ET AL 2,355,349

SIGNAL IMPULSE SENDING SYSTEM FiI Led June 21, 1940 s Sheets-Sheet 2 J7'z0z-n'f0r-5: J5/zrz 7271426610 c/r 11522 F Cry 25er- A 8; 1944. J. H. WHEELOCK- HAL 3 5, 9

SIGNAL IMPULSE SENDING SYSTEM Filed June 21, 1940 5 Sheets-Sheet 5 17' 8 d5 0 O O \d 4 5'34 12 41 Q v 7 l Q A l a. 45

3'9 v 4 521.- 35? r 4 7 L Patented Aug. 8, 1944 2,355,349 SIGNAL EIPULSE SENDING SYSTEM John H. Wheelock,

Fitzwilliam, N. H., and Hugo F. Cypser, New York, N. Y., assignors to Signal Engineering &

Manufacturing Company, New

York, N. Y., a corporation of Massachusetts Application June 21, 1940, Serial No. 341,740

4 Claims.

The present invention relates to an electrical impulse sending system for controlling the operation of suitable devices for sounding or displaying signals at diiferent locations throughout a building, or other establishment in which the system is installed. Calling and locating individuals by code number, or transmission of special signals are well known uses of such a system.

Signal code sending systems of the above indicated character are customarily employed in association with telephone apparatus, a usual arrangement being to have the code determining and sending mechanism of the system installed where it may be conveniently actuated by the operator at a telephone switchboard. While a source of energy for operating telephone apparatus is available at any switchboard, it has been the accepted practice to provide for the energization of such code sending mechanism, as well as the signals under the control thereof from the usual commercial lighting circuit, largely due to the fact that telephone current does not provide sufficient power. As a result all parts of the system must be installed in. accordance with the regulations governing the distribution of current at 110 volts or higher, in contrast to the relatively low cost installation of apparatus operated from power available at a telephone switchboard.

According to the present invention, there is provided a signal impulse sending system that is adapted to be operated from the electrical energy available at a telephone switchboard, both as regards the signal impulse sending mechanism, and the signals operated thereby. The improved system is so arranged as to draw energy from a source of telephone ringing circuit only at the rate available, and to utilize this energy at a greatly increased rate to operate signals of the loud sounding type ordinarily requiring energization from a commercial power source. Thus the entire system of the present invention is adapted to be installed with the same facility and low cost as associated with the installation of ordinary telephone apparatus. I

The above and other advantageous features of the invention will hereinafter more fully appear from the following description, with reference to the accompanying drawings, in which:

Fig. 1 is a diagrammatic View of'a system embodying the invention, in its normal, non-oper ating condition.

Fig. 2 illustrates the system of Fig. 1, after the initiation of the sending of a signal impulse- Fig. 3 illustrates the system of Fig. 1 in the. act of transmitting a signal impulse.

Fig. 4 is a view in side ping relay employed in the Fig. 5 is a detail perspective view of a timing device cooperating with the relay.

Referring first to Fig. 1, the system includes a code determining device of any suitable type shown, for purposes of illustration, as comprising a key K, manually operable to set up a code combination with respect to associated contacts k-I, k-2, 10-3, etc. These key operated contacts are connected to correspondingly designated contacts dl, d-2, d 3, etc. of a distributing device D. The contacts d|, d-2, etc. are arranged around the periphery of a ring I, and a double arm 2 mounted on a shaft 3 passing through the ring I, is adapted to successively engage the contacts d-I, d 2, etc., while continuously bearing on the ring I. The shaft 3 of the distributing device D, also carries a ratchet wheel 4 that is adapted to be turned by a pivotally mounted pawl 5, connected by a link 6 to the armature I of a stepping relay R. The relay provides a winding 8, energization of which attracts the armature 1 and causes the pawl 5 to turn the ratchet wheel 4 through an angle suflicient to move the arm 2 from one distributor contact to another. The armature I carries a pivoted contact member 9 normally in engagement with a stationary back contact I0 when the windelevation of the stepsystem.

; ing 8 is in its deenergized condition.

One terminal of the stepping relay winding 8 is connected to one terminal of a condenser II through a pair of normally closed contacts I2, forming part of the relay, as shown in Fig. 4. The other terminal of winding 8 is connected to the other terminal of the condenser II through a pair of normally closed contacts I3 adapted to be operated by the key K, as hereafter described. The winding 8 is thus normally connected across the terminals of condenser II, so as to maintain the same in a discharged condition.

The terminals of condenser H are also connected to the output side of a full wave rectifier M, the input side of which is connected to one main I5a, energized from a source indicated as being that usually employed in a telephone ringing circuit, namely, a source operating at volts, 20 cycles. The other main E52) from the 90/20 source, is adapted to be connected to the input side of the IE leading to a pair of normally open contacts I1, one of which is received in a notch 53 provided on the periphery of a control disk 5 8. The disk I9 is mounted on a shaft 20 connected by reduction gearing, 2| to the shaft 3 of the distribrectifier I 4 through conductors 2 uting device D, for a purpose which will later appear.

The conductors 16 leading to open contacts H are connected in parallel to conductors 22, lead-.

with the rectifier l4 being adapted for energiza tion upon closure of either pair of contacts H or The ring I of the distributing device D is connected to one contact l1, so that closure of the contacts I! by turning of the control disk as,

is adapted to connect the ring i to the supply main I51). The other supply-main l5a is connected by a conductor 25 to one of a pair of parallel signal energizing mains 25 extending through the system, across which mains 25 are connected a plurality of signal units 21, of a particular construction adapted for the present system. The other signal energizing main Z6 is connected to the contact ill of the stepping relay R, the other contact of which is connected by a conductor 28 to a common key contact Ic-il, which is always in engagement with the key K. Consequently, the signal energizing mains 26 will be connected to the source of telephone ringing currentenergizing the mains a and [5b, only in accordance with the arrangement of those particular key contacts k-l, 70-2, etc. that are connected to the common contact ki upon depression of a particular key K.

Each signal unit 21 comprises the apparatus enclosed within the dotand dash lines at the end of the mains 26, such a unit being more fully shown and described in the co-pending application of Hugo F. Cypser, one of the applicants herein, filed of even date, Serial No. 341,739. For the purposes of the present application, it is sufficient to state that each unit 21 consists of a suitable signal S of the single stroke solenoid type, having a winding 29 adapted to be connected across the terminals of a condenser 30 when the relatively movable contacts 3| and 32 of a relay are engaged. One terminal of the condenser 30 is connected in series with thewinding 33 of the relay, and the condenser is adapted to be charged from the output side of 'a rectifier 133, when therelay pulls up to disengage the movable contact member 32 from the stationary contact 35. The input side of the rectifier 34 is connected across the signal energizing mains 26by conductors and normally the elements of each unit .21 are in the condition of Fig. 1, withthecondenser 3i] discharged through the operating winding 29 of the signal S.

Upon pressing the key K all the way in, as shown in dotted lines in Fig. 2, its insulating tip 23 closes the normally open contacts 23, and simultaneously opens the contacts i3, movement of the lower contact 23 being imparted to the upper contact I3 by an operating member 36 of insulating material. Closure of contacts 23 establishes a shunt circuit around the then open contacts I! and completes the circuit to the input side of the rectifier M from the mains Ma and I51), thereby causing the rectifier to impress a charging voltage on the condenser E l. The condenser thus becomes fully charged, since it is not for the moment short circuited by the operating winding 8 of the stepping relay,

. ply main opening of the contacts 13 in circuit with the winding 8, by the depressed key K.

Upon release of the key K, a spring 31 returns the key to an intermediate position, in which it is held by a latch 38. In the latched position of the key K, code determining contacts kr-i, k-3

and k4 are engaged by the key K, so that all connected to the comto the contacts 9 and Patent No. 1,823,585, issued September 15, 1931.

Upon return of the key K to its latched position, the contacts 23 are reopened, while the contacts 13 are reclosed, as the insulating tip 24 of the key permits these contacts to assume an unfiexed condition. When the contacts l3 close, the winding 8 of the stepping relay R is connected directly across the terminals of the then charged condenser ll, whereupon the relay R pulls up, in response to the full energization of its Winding 8 by the condenser discharge. It is to be noted that the relay R is operated entirely by energy stored in the charged condenser H, and without drawing any current from the 90 volt, 2O cycle ringing current source.

Pulling up of the relay armature 1 by the winding 8 turns the ratchet 4 through the space of one tooth, thereby engaging the distributor arm 2 with the first contact d-i. This initial turning of the shaft 3 is also imparted to the control disk l9 through the reduction gearing 2!, so as to close the contacts I! as the lower contact rides out of the notch E8. The contacts l-l will then remain closed during one complete revolution of the disk 19, which will require thirty-six successive operations of the relay R, with twelve teeth on the ratchet 4 and a speed relation of three to one between the shafts 3 and 29. Closure of the contacts H on the first pull up of the relay R, therefore establishes a circuit from the sup- I5b through to the common key contact 10-0, but the signal energizing mains 2'5 are not immediately energized, due to the fact that the stepper relay contacts l0 are then open, as indicated in dotted lines in Fig. 2.

Just after the stepper relay'armature I pulls up, upon energization of the winding 8 by discharge of the condenser H, an actuator 39,- forming part of a timing'device 23, opens the contacts I2 that are connected in the circuit of the winding 8. Thereupon, the relay armature 1 drops back, leaving the condenser H in a dise charged condition. When this occurs, the movable contact member 9 again engages the stationary contact if] of the relay, thereby com pleting connection of the signal energizing mains 2b to the 90/20 mains I511 and ISbthrough, the circuits previously prepared by depression v(lithe; key K and turning of the arm 2 and ;'control; disk l9. Energization of the mains ZBthen cOnnects the input side of the rectifier: 34I0f :each

signal unit 2'! to the 90/26 source; With-there due' to the sult that each relay winding 33 pulls up through, the signal winding 29, to remove the? winding 29 from across the terminals of the? condenser 30, as shown in Fig. 2. The condenser? 301then becomes charged from the output,'side ::of1 thev rectifier 34, and remains in thi's'c'on'ditidn," due to the fact that sufficient current'ztraverses the relay winding 33. through J the resistor; 33a,I .to hold up the movable'contact member i32'.i1'Ihere'=.

armature drops back, upon breaking of the circuit of the winding 8. As best shown in Fig. 5, the actuator 39 fo'rms part of a timing device 40 of the spring wind-up type, such as is shown in Wheelock 8; Humphreys application, Serial No. 183,053, filed January 3, 1938, now patent.

No. 2,235,273. As the armature I pulls up, the

link 6 turns an arm 4|, which winds up a spring driven ratchet 42 on a shaft 43, before being released by a pin 44 as the armature completes its upward movement. Thereafter, the shaft 43 turns the actuator shaft 45 through an angle represented by the displacement of one projection 39a, which opens the contacts l2, and then recloses them after a predetermined interval.

Assuming that the contacts I2 are held open through a period of one or more seconds, it is obvious that the condenser I I will again become charged, due to the fact that the contacts I! remain closed after the first step of the relay R, and throughout the operating cycle of the sys tem. Therefore, when the timing device 49 per,- mits contacts l2 tov reclose, the condenser H again discharges into the winding ,8, to cause the armature 1 to again pull up and turn the shaft 3 through another step. Since the relay breaks the circuit of its winding 8 at the contacts l2, oneach pull up, it follows that the successive charging and discharging of the condenser will cause the stepper relay R to be operated intermittently, until a complete revolution of the disk I9 again permits the lower contact I! to enter the notch I 8 and bring the stepping mechanism to rest.

Since the dropping back of the relay armature I after its first pull up results in charging of all the condensers 30 of the several signal units 21, as shown in Fig. 2, it follows that the next or second pull up of the relay armature I will result in simultaneous operation of all of the signals S through discharge of the several condensers 30. This is due to the fact that as the relay contacts 9 and I9 open in response to pulling up of the armature 1, the resulting disconnection of one main 26 from the 90/20 source, deenergizes all of the signal unit relay windings 33, whereupon each charged signal condenser 30 discharges into its associated signal winding 29, as the contact 3| is engaged by the contact 32, as shown in Fig. 3.

The first impulse of the signal code is therefore given by the signals as the relay R pulls up, to turn the shaft 3 through its second step, and thereby move the arm 2 from the contact dl to the contact d--2. However, when the relay armature 1 drops back a second time, the several signal operating condensers 30 are not charged, due to the fact that the code determining contact w2 is not engaged by the depressed key K. However, as continued operation of the stepping relay R causes the arm 2 to successively engage the distributor contacts (1-3 and 11-4, the resulting dropping back of the armature I after each such engagement, will result in charging of the several condensers 39, and the operation of the signals S by the discharge of the condensers, as the relay R pulls up for its fourth and fifth steps. Therefore, with the form of the key K shown in the drawings,continued step-by-step operation of the distributor arm- 2 through a complete revolution will result in the operation of the signals S once, then alpause, followed by operation of the signals twice,v to transmit the code sequence Twelve. This sequence will be transmitted three times before the opening of contacts 11 by; the disk I9 disconnects the rectifier l4.

The net result of the above described opera tion of the system is that when the signals S are operated on the pull up of the stepper relay R, very little current is broken at the contact ll], due to the fact that the windings 33 of the signal control relays are then in series with the resistors 33a across the terminals of the then charged condensers 30. Furthermore, when the arm 2 moves from one distributor contact to another, there is no current flowing, due to the fact that the circuit from the supply main 15b has already been broken at the contact I 0. Therefore, arcin in the system is reduced-to a minimum, since the signal operating current,

due to the discharge of a condenser 38, is no longerflowing when the contacts 34 and 32 of a signal operating relay are opened.

In considering the operation of the system as a whole, it is apparent that the only current flow from the /20 source of telephone ringing current is that required to first charge the condenser II to store up energy for operating the stepper relay R, and then to simultaneously charge the several signal unit condensers 30 to store up energy for operating the signal windings 29. Asmin ev n a r la ively high condenser charging current of as much as 15 mil. amperes for each signal unit, six bells can be operated from a 90/20 source, with a current consumption of less than mil. amperes, which is well within the limits of the power available at any telephone switchboard. It is apparent then that by the present invention there is provided a complete impulse sending system, in which the operating mechanism, as well as the signals, can be energized entirely from a source of telephone ringing current available at any telephone switchboard, without any connection whatsoever with a commercial power'source. Furthermore, it is possible to employ in this system, standard signals of the loud sounding type, each requiring 1. An impulse sending system, comprising in combination, a source of electrical energy having a limited instantaneous rate of power output, electrically operated signals, an electrically operated device for sending electrical impulses to said signals, with said signals and sending device having instantaneous rates of power intake higher than the power output rate available at said source, condensers for receiving charges of current from said source at the limited power output rate available, and means in the system, including said impulse sending device, for successively charging saidcondensers and discharging the stored energy of said condensers, for each impulse sent, to operate first said sending device andthen said signals at instantaneous rates of power input greater than the charging rates of said condensers from said source.

2. A signal sending system, comprising in combination, a source of electrical energy of the character that is employed for telephone ringing current, said source having a limited instantaneous rate of power output, signals providing operating windings, a step-by-step impulse send ing device having an operating windingwithsaid windings requiring instantaneous ratesof power input greater than that available at said source in order to actuate said device and signals, a

code determining device associated withsaid impulse sending device, means for rectifying current into unidirectional :current, condensers adapted to be charged by the rectified current,- and means including said step-by-step impulse sending device and set in operation by the initial actuation of said determining device for alternately charging said condensers by rectified current, and discharging them into the operating windings of said sending device and signals. 1

3. A signal sending system, comprising in combination, a source of electrical energy of the said step-by-step sending device and set in operation by the initial actuation of said code determining device for alternately charging said condensers by rectified current and discharging them into theoperating windings of said sending deviceand signals.

4. A signal sending system, comprising in combination, a source of electrical energy of the character that is employed for telephone ringing current, said source having a limited instantaneous rate of power output, electrically operated signals providing windings, an electrically operated step-by-step impulse sending device having a winding,'with each of said windings requiring instantaneous rates of power input greater than that available at said source in order to actuate said device and signals, a code determining device associated with said impulse sending device, means for rectifying the source current into unidirectional current, condensers associated with each of said windings, means in-- sending device for charging and discharging the remaining condensers with respect to their associated signal windings to cause operation of the signals in accordance with a code set up by said determining device.

JOHN H. WHEELOCK. HUGO F. CYPSER.

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