US927663A - Harmonic signaling system and magneto hand-generator therefor. - Google Patents

Description

R. H. MANSON. SYSTEM AND MAGNETO HAND GENERATOR TE APPLICATION FILED TBB. 1, 1907.

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R. H. MANSON. EAEMONIG STGNALING SYSTEM AND MAGNETO HAND GENERATOR THEEETOE. APPLICATION FILED FEB.1, 1907.

927,663, Patented July 13, 1909.

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R. H. MANSON. HARMONG SIGNALING SYSTEM AND MAGNET() HAND GENERATOR THEREFOR. APPLICATION YILED FEB.1, 1907.

927,663, I Patented July 13, 1909.

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I-I. MANSON, OI" ELYRIA, OHIO, ASSIGNOR TO 'll'IE DEAN ELECTRIC COMPANY, OF ELYRIA,

OI-IIO, A CORPORATION OF OHIO.

HARMONIC SIGNALING SYSTEM AND MAGNETO HAND-GENERATOR THEREFOR.

To cltwhom it may concern:

Be it known that I, RAY H. HANsoN, a citizen of the United States, residing at Elyria, in the county of Lorain and State of Ohio, have invented certain new and useful Improvements in Harmonic Signaling Systems and Magneto IIand- Generators Therefor, of which the following is a speci tication, reference being had therein to the accompanying drawing.

This invention relates to telephone systems and especially to harmonic signaling systems.

It has for its object the production of means whereby an anmmciator or indicator may be actuated from a sub-station or other point on a line, without actuating any o'll the ringers at the subscribers" stations.

The invention is particularly applicable to what are known as rural or farmers lines, whereof the length and resistance are too great to permit of the use of common battery, and therefore the old fashioned inagneto hand generator is employed for purposes of signaling. At the central station constituting' the terminus of such a line the operator is provided with ringing generators as used in all systems: and at` the sub-stations. the hand generators are located usually in open bridges of the line, closed when signaling.

IVhen ordinary hand generators are used in the manner indicated, with harmonic ringers, there is a strong tendency for the low frequency ringers to be actuated every time a subscriber is calling central. By low frequency ringers in this case I particularly refer' to the 16 and 33 cycle ringers, where the complete set of frequencies employed are: 1G, 33, 50, 66. Of course these frequencies may be made any thing desired, but are referred to herein because they are standard.

The present design consists specitically of a eommutator arrangementl adapted to regulate thel current from the hand generator, so as to prevent its ringing any oit' the bells Specification of Letters Patent.

Application filed February 1, 1907.

Patented July 13, 1909.

Serial No. 355,207.

at the sub-stations when signaling the cx* change for a connection or when clearing out.

I have found that an ordinary alternating current generator will operate the 1G cycle bell even when the line terminates in a 100 ohm annunciator at t-he switchboard. rl`his is true when a low voltage generator is used, such as a three bar alternating current generator with one magnet reversed so as to neutralize one of the other magnets and give in effect a one bar generator. I have also found that three bar direct current generators and pulsating current generators will operate the low frequency harmonic ringers. A special drum wound armature with a large number of connuutator segments will not do this but. the tamstruction cannoty be carried t-o this point on account'. of expense in manufacture and in carrying special stock therefor. Instead of such an armature and commutator, I prefer to employ a special commutator having one or more contact points wired in series with the terminals of the generator, which is arranged to give alternating current. The form of connnutator actually employed by me in practice has only one point, and it breaks up the alternating current into widely separated periods ot' a single impulse or wave each, so that there are no alternations in continuity to start the low frequency bells to vibrating. rlhe single point of the commutator makes contacty only once during a complete revolution of the armature, and the duration of contact is very short.. The best results are obtained in an ordinary sized generator with a contact 1/16 long on a 5/8 or 3/4 diameter commutator. The current thrown on the line by this commutator apparently has a very high and peaked curve, and while not of sutliclent volume or strength to operate the ringers it is sufficient to operate the switchboard annunciators with ease.

Bv the use of my new generator I am enabled to employ a high wound bridging CIK til

switchboard annunciator, thereby preventing the shunting of voice current when two parties on the line are talking.

Figure 1 is a side elevation of my generator. Fig. 2 is an end elevation thereof. Fig. 3 is a perspective of the separated parts ofthe commutator and a portion of the armature spindle. Fig. t is a sectional view of one end of the armature spindle and the commutator. Fig. 5 is a diagram of a current curve. Fig. G is a diagrammatic view showing a line, a switchboard drop, three substation ringers bridged across the line, and my improved generator also bridged at a fourth station. Fig. 7 is a similar diagram with the substation ringers in ground taps.

Referring to F ig. 1, 1 designates the field magnets of the generator, of which there are three and to which is secured the plate 2 having apertures at 3 to receive bolts for attachment to a support. The pole piece et of the armature has secured to it at each end a pair of supporting plates 5 and G each provided with an extension in which is journaled the main shaft 7. Carried by the main shaft and meshing with a pinion 8 on the armature shaft 9 is the main or driving gear wheel 10 operated in the usual manner by the crank 11. The line contacts 12 and 13 are carried upon a frame 14 secured above the armature shaft 9 on the plate 5 and so positioned as to be engaged by the projecting insulated end 15 of the shaft 7 when the generator is operated. The end of the armature shaft 9 is hollowed out and is provided with an insulating bushing 16 in which the commutator spindle 17 is secured by means of the pin 18 which passes through a bushed opening in the shaft 9 and is insulated from the shaft by the collar 19. To the end of the commut-ator spindle 17 is secured the commutator C3 comprising a pair of metallic disks 2O having projecting teeth 21 and separated by the disk of insulation 22. This disk of insulation is provided with a notch 23 which lies between the two teeth 21 of the disks 20, so as to insure positive contact with the brush 24 carried by the frame 14. The parts 2O and 22 are secured together by bolts 25 passing through all the disks and electrically connecting the disks 20.

The frame 14 is electrically in connection with the field magnets and supports an arm 27 insulated therefrom but which is in electrical connection with the spring 13. This arm is provided with a line terminal binding post 2G. The other line terminal binding post is indicated at 2S and is formed upon the plate The brush 24 normally bears against the insulation 22 until the shaft is turned sufficiently to bring the lugs 21 of the disks 2O in vcontact therewith at which time the aperture 23 allows the spring to engage said lugs. The brush 24 being in' engagement with the spring 12 and the spring 13 being at that time forced over into engagement with the spring 12 by the operation of the crank 11 in circuit is thus completed through the generator. From the time of last contact of the teeth 21 with the brush 24 there is no current whatever passing out over the line as the circuit is broken by reason of the brush engaging the insulating disk 22 and the E. M. F. in the generator piles up so that when the lugs again contact with the brush a high peaked wave is thrown on the line through the bridge wires. This current is not of suflicient volume or strength or of long enough duration to operate the low frequency bells butis strong enough to operate the switchboard drop.

ln Fig. 6 I have shown four stations A, B, G and D, the first three of which are indicated by the bells B and the condensers Cl and the last one of which is indicated by the generator heretofore described, in a diagrammatic way. S points out the switchboard drop at the central oflice, which when the generator is operated indicates to central that a call has been made and connection is desired. The cord circuit and other apparatus l have not shown as it is deemed unnecessary to the understanding of this invention.

In Fig. 7 l have shown a similar system to that of Fig, (3 except that the stations A2, B2, C2, D2, E2, F2 and G2 are grounded.

As before stated, when a generator as for instance that at station D in Fig. 6 was operated the low frequency bells of other subscribers on the same line were operated, resulting in confusion at the substations and also at the central otlice because the switchboard drop and the low frequency bells were operated simultaneously.

In a modified form of my generator the commutato-r is mounted on the crank shaft and may be fitted with one or more teeth with the result that without changing the gear ratios ordinarily used in standard generators and without special formation of the couunutator, impulses of low frequency may be delivered from such generator and that such frequency will not be adapted to operate harmonic ringers. ln connection with this form of generator, l. have found, however, that without specially designing the gears, the impulses delivered are irregular in value and that in many cases a large number of turns of the crank is required bctween impulses of maximum electromotive force. eflicient operation of the apparatus designed to be actuated by such generator which may, however, be overcome by constructing the eonnnutator on the crank shaft with but one tooth, and by using gears of even ratio.

Thus there is an onaortunitv for inceases Such an arrangement howeverv does not einploy standard gearing, and for this reason I prefer the arrangement already described, in Which the coniniutritor is located on the armature shaft and has but a single tooth, making contact. but once for a short space of time during` each rotation of the arniature. The point at ivhich this shall occur is definitely fixed, so as to give the proper current effect.

In considering the invention it must be borne in niind that for all harmonic signaling of successful commercial type, it takes more than a momentary impulse to start vibration of a ringer. This however is also truc in many eases of resonance. The trot of a dog ivill not at first start a bridge to vibrating, but if maintained for a feiv seconds it Will inevitably do so by reason of the cumulation of energy. it is upon this principle that my present invention' is based. li`ig. 5 shows a eiirrent curve approximating vthe wave forni produced in my generator. (.)wing to the sudden discharge when the momentary contact is made at the commutator, there is a jerk or peak which While it rims up high above the neutral line, is of small area, and th-i amount of energy represented is e()rrespondingly small. Several of these peaked Waves, if run together, would start the bells to ringing, but Vl separate them so that they have no power of starting the vibration. ln other words, l. break the resonance by destroying coutinuity.

Vhile l have shown a bridging circuit, it is to be understood that the generator is useful in other circuits, and also that this circuit inay be used with other specific forms of generator, so long as the essential principle is employed, of thus preventing resonant effects.

All non-essential changes and departures l include ivithin the scope of my claims.

Having thus described my invention what I claim and desire to secure by Letters Patent is:

1. ln a telephone system, a line circuit, a timed ringer at a substation connected thereto, such ringer adapted to be operated by periodic current of definite frequency, a central office, a line signal at the central office, and means at a substation on thc line for sending ivavcs of current through such ringer and such line signal, such waves of current adapted to operate the `line signal, and each of such waves lacking the characteristics necessary for operating` such ringer.

2. In a telephone system, a line circuit, a tiiiied ringer at a substation connected thereto, such ringer adapted to be operated by periodic current of definite frequency, a central office, a line signal at the central office, and means at the substation on the vline for sending waves of current through such ringer and such line signal, such waves of current adapted to operate the line signal and `when of the proper frequency lacking the other properties necessary for operating such ringer.

3. In a telephone system. a line circuit and a timed ringer at a substation connected thereto, such ringer adapted to be operated by periodic current of definite frequency, a central office, a line signal at such central ottico and means at a substation on the line for delivering current in recurring waves to such line circuit, such Waves adapted to operate such line signal, each of such Waves lacking the energy necessary to operate siicli ringer.

it. In a telephone system, a line circuit and a timed ringer connected thereto, siicli ringer adapted to be operated by periodic current of definite frequency, a central office, a line signal at such central office and means for delivering current in recurring waves to such line circuit, such waves adapted to operate suoli line signal, each of such waves when adapted in frequency lacking the energy necessary to operate such ringer.

5. In a telephone system, a line circuit and a timed ringer connected thereto, such ringer adapted to be operated by periodic current of definite frequency, a central office. a liue signal at such central oHice, a generator for delivering periodic current in recurring waves to such line circuit, such waves adapted to operate such line signal but of too short duration to operate such ringer.

G. In a telephone system, a line circuit and a timed ringer connected thereto, such ringer adapted to be operated by periodic current of definite frequency, a central office, a line signal at such central office, a generator for delivering periodic current in recurring waves to such line circuit, such Waves adapted to operate such line signal, each of siicli Waves when adapted in frequency being of too short duration to operate such ringer.

7. ln a telephone system, a line circuit and a timed ringer connected thereto, such ringer adapted to be Operated by periodic current of definite frequency, a central ollice, a line signal at such central oflice and means for delivering current in recurring Waves to such line. circuit, such waves adapted to operate such line signal and of the proper maximum electroniotive :force and frequency but of too short duration to operate such ringer.

8. ln a telephone system, a line circuit, a timed ringer at a substation connected thereto, such ringer adapted to be operated by periodic current of definite frequency, a central office, a line signal at the central otiice, and means at a substation on the line for sending Waves of current through such ringer and such line signal, and each of such Waves of current of n forni not adapted to operate such ringer.

9. 1n n telephone system, a line Circuit, a tuned ringer at a substation connected thereto, such ringer adapted to be operated by periodic current of definite frequency, a central office, a line signal at the central office, and ineens at a substation on the line for sending Waves of current through such ringer and such line signal, and such Waves of current of a forni not adapted either singly or together to operate such ringer.

In testimony whereof I aiX lny signature in presence of two Witnesses.

RAY H. MANSON. Vitnesses:

SEDNEY A. BEYLAND, S. J. ROBERTS.

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