US1502493A - Time-indicating apparatus - Google Patents

Description

July 22 1924.

H. E. WARREN TIME INDICATING APPARATUS Filed April 15 1918 I5 Sheets-Sheot 1 H. E. WARREN TIME INDICATING APPARATUS July 22. 1924. 1,502,493

Filed April 15 1918 3 Sheets-Sheet 2 R al/1.4 TIMI IN VEN TOR.

July 22 1924.

H. E. WARREN TIME INDICA'IING APPARATUS Filed Aprn 15 1918 3 Sheets-Shut 5 INVENTOR. W6. WW

ATTORNEY Patented July 22, 1924.

UNITED STATES PATENT OFFICE.

HENRY E. WARREN, OF ASHLAND, MASSACHUSETTS, ASSIGNOR TO WARREN CLOCI: COMPANY. OF ASHLAND, MASSACHUSETTS, A CORPORATION OF MAINE.

TIME-INDIGATING APPARATUS.

Application filed April 15, 1918. Serial No. 228,688.

To all whom it may concern.

Be it known that I, HENRY E. WARREN, a citizen of the United States, residing in Ashland, county of Middlesex, and State of Massachusetts, have invented an Improvement in Time-Indicatin Apparatus, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

My invention relates to clocks or like apparatus, and in one of its as ects rel..tes to clocks designed to compare tlme indications derived from independent sources; as for instance the time indications given by the standard clock Work with those had from a synchronous alternating current motor. The invention has for its general object an improved arrangement 'ofparts affording an accurate, reliable and serviceable apparatus in which such indications may be readily compared and for correcting variations in time indications.

My invention has particular application where it is desired to regulate one of the sourcesof time indications so that two such independent sources may be made to give substantially the same time indications; for instance where it is desired to regulate the frequency of the alternating current to synchronous motors giving time indications so that their indications are made to agree with those of a standard time piece in the manner disclosed in Letters Patent No. 1,283,431 issued in my name on October 29, 1918.

To. give effect to my invention, I have found it expedient to have hands which are impelled separately by the independent sources of time, traverse the same indicating dial. Such an arrangement facilitates the exact visual comparison of the indications, while a concentric arrangement. ermits the relative angular displacement o the hands being made an index of the error which may exist between the respective time indications given by the two sources.

In further giving eifect to my invention, it is desirable that the source which is made the standard of comparison should have very accurate time keeping qualities, and also have means for correcting with great precision any deviations in its time indications from standard Observatory time signals such as are regularly sent out from Washington. To this end I have arranged, in a novel manner, to kee the spring tens on in the source, or time lieeper serving as the standard of comparison, substantially constant, by having its spring or driving means re-wound constantly by as much as it runs down; the rewinding may be conveniently accomplished by the synchronous motor which gives the other time indications. Also to correct for the deviations in the standard time keeper from the standard time signals I provide my standard time keeper with a device for accelerating or decelerating at will the movement of the timing element or pendulum, in my time keeper.

Such device is preferably an electro-magnetic one and is made with advantage, to function in two ways, one by applying a constant correction continuously to the movement of the timing element, the other by applying a definite correction to such movement for a limited time only.

These and other features of this invention will be pointed out in the claims at the end of this specification.

Fig. 1 is a front elevation of a time indicating apparatus embodying the invention.

Fig. 2, a side elevation of the apparatus shown in Fig. 1.

I, Fig. 3, a diagram illustrating one'form of mechanism for regulating or setting the apparatus shown in Figs. 1 and 2,

Fig. 4, a plan of a modified form of time indicating apparatus and Fig. 5, a front elevation of the apparatus shown in Fig. 4.

Referring to Figs. 1, 2 and 3, 10 and 11 represent the pendulum bob and rod of a clock movement having an escapement 12 and wheel 13, to which power is transmitted from the main spring 14 through gears and pinions15, 1e, 17, I8, 19, 20, 21, 22, in a manner well understood, and motion from the escapement is transmitted by pinion 23 and ear 24 to a sleeve 25, which carries a ban 26, which cooperates with a ial a having'numerals 1 to 5, which indicatethat the hand 26 makes a com lete revolution? once in five minutes. The hand 26 constitutes a revolving member or element indi cative of standard time.

27 represents a self-starting synchronous motor, which may be such as is shown and described in another application Se. No. 138,763 filed by me Dec. 26, 1916. The motor 27 drives a shaft 29 through a slip coupling 28, and motion is transmitted from the shaft 29 by pinioii 30, gears 31, 32, and pinion 33 to shaft 34 upon which is fastened the hand 35. The shaft 34 extends through the sleeve 25 and the hand 35 is thus concentrically mounted with respect to the hand 26 and constitutes, a time element driven by the synchronous motor 27, and the ratio of the gears connecting the motor 27 with the hand 35 is-such that the latter revolves at precisely the same rate as the hand 26-and coo erates with'the dial a.-

nergy is also transmitted from the gear 31 through pinion 36, gear 37, pinion 38 and gear 39, pawl 41 and ratchet wheel 42 to shaft 40, to which'the inner end of the clock s ring 14 is fastened, the outer end of whic spring is fastened to the gear 15.

'Iheratio ofthe gears from 31 to 39 is such, that normally the sprin 14 will be wound b the motor 27 exact y as fast as the en ulum permits it to. be unwound. It will thus be seen that variation in the frequency of the alternating current which operates the synchronous motor 27, influences the rate at which the hand 35 is revolved over the dial a, and consequently variation in the frequency of the current is made lrnown to the operator at the power station in which the master clock is located by noting the osition of the hand 35 with relation to the hand 26.

Provision is made fonregulating. the rate of the pendulum with great convenience and precision, '"which is accomplished as herein shown by providing the pendulum.

10 at its lower end with a permanent steel bar magnet 50, which cooperates with and swings across flat coils of insulated wire 51 and 52, so that the magnetic lines preceding from the magnet 50 are constantly cutting the conductors in these coils. B

means of a battery of two or more cel s 53, I apply constant potential across the terminals of two potentiometers 54 and of known construction, and by means of sliding contacts 56 and 57, the position of which is indicated bymeans of scales 58 and 59, current= atplus or minus potential istaken from the resistances 60 or 61. Contact 56 is connected by the wire 62, contact maker 63 and 64, and conductor 65 at one end of coil 52, the other end of'whichis connected with the middle point of the batteries 53, so that if contact maker 63 and 64 is closed by pushing down on the knob 66, current will flow in either one direction or the other through coil 52, accordin to the position of sliding contact 56, WlllCll will be indicated on the scale 58.-

Current from potentiometer 55 flows throu h conductor 67 to one end of coil 51 and tl1us,'by connection 68 which is common to both coils 51 and 52, back tothe middle point of the battery 53. Conseuently current may flow in either direction mm the coil 51 according to the indication of the sliding contact 57 on the. scale 59. Graduations on the scales 58 and 59 are preferably made in seconds. The knob 66 may be held down after being depressed by catch 69, which is released once in every twelve hours by the pin 70 in the hour hand gear 71 of 'the clock. Consequentl the circuit through coil 52 which lnclud es potentiometer 54 can onl be. left closed for'somewhat less than two ve hours. The effect of current passing through either of coils 51 or 52 is to accelerate or retard motion of the pendulum 10 according to the direction of the current through these coils, and the amount of acceleration or retardation will depend upon the strength of the current. This is determined by the Potentiometers 54 and 55. If the sliding contacts 56 and 7 are in their mid position there will be zero potential across the terminals of the coils and consequently no current will flow. 011 deviation of the sliding contacts in one direction, the effect of the current will be to make the clock run faster, and the deviation of the slidin contact in the other direction will make t e clock run slower.

The scale graduations 59 are preferably such as will correspond to the acceleration or retardation of the clock of one second in twenty-four hours, and the scale graduations 58 correspond preferably with acceleration or retardation of one second in somewhat less than twelve hours. AS a result of this arran ement, the clock may be set by means 0 potentiometer -54, by depressing the knob 66 and sliding the contactor 56 so that the other end which passes over the scale will correspond with the number of seconds which the clock should gain or lose. This operation of setting must be performed -just after the pin 70 has permitted the arm 72 to drop so that the catch 69 may become effective, and it is usually arranged so that this result will take place about noon or mid-night when clocks are normally set.

The retardation or acceleration produced through potentiometer 54 will be effective for the next twelve hours only, so that the clock will not gain nor lose after the catch 69 has been released. The potentiometer 55 however, on the other hand remains in circuit constantl and consequently produties a constant e ec-t through coil 51 on the pendulum 10. Therefore by means of 'mally with an error less than one operator in an electric power station. The

synchronous motor 27 is connected to the bus bars so as to respond to the frequency of the alternating current being generated. The spring 14 is wound at the point 43 and the pendulum is started. The hands 35, 26 of the clock are then set to correspond with the true time, being exactly over each other.

The operator is instructed to adjust thefrequency so as to maintain these hands together. He can do this very easily by observing the clock occasionally, say at half hour intervals and knowing'whether the hand 35 has a tendenc to gain or lose in respect to hand 26. f he finds that the hand 35 is gaining he will slow down the speed governors of the turbines, or speed them up if he finds that the hand 35 is losing.

Experience has demonstrated that in large power stations it is very easy to keep 'the hands together within two or three seconds. by comparatively infrequent adjustment of the speed governors. Each day, at noontime preferably, the readin of the hand 26 should be compared with t e true time 'received by wireless ,from- Washington or otherwise determined, and then the rate of the clock should be corrected by means of potentiometer 55 and the error of the clock should be corrected by potentiometer 54. clock made in this manner, will run norsecond per day. The motor 27, which is running constantly will keep the spring '14 which drives the pendulum. always wound at exactly the same tension.

In Fig. 1, the standard 3 time keeper: is shown as provided with amain s ring and controlled by a pendulum, but it is not desired to limit the invention in this respect, as a duplex master clock may be provided in which the standard time keeper may be otherwise driven as for instance by a synchronous motor M as shown in Figs. 4and 5. so that its rate is controlled by the freqliliency of the current which is supplied to temotorM. W

The master clock shown in Figs, 4 and 5. may be used in the .power house'ofan isolatedplant and the alternating current for the motor M may come from a large power station which is provided with a pen-- dulum master clock shown in Fig. 1, and the current; so plied to the second synchronous motor 27 in Figs. 4 and 5 may be received from the bus bars of the isolated plant, for example, a manufacturing plant which supplies its own power. It willthus be seen that by means of the modified master clock shown in Figs. 4 and 5, it is easy for the engineer of the isolatedplant to maintain the same average frequency as the large power station without purchasing-any electrical energy from the large power station, excepting the insignificant amount necessary to drive the tiny synchronous motor M.

The motor M is connected through gears 80. 81, 82, 83 with the hand 26, and the motor 27 through .gears- 30, 31, 32. 33, with the hand 35. The method of using the clock shown in Figs. 4 and 5 is the same as has been heretofore described. -The means for regulating the rate of the pendulum of the standard time keeper is not herein claimed as it forms the subject-matter of a divisional application Serial Number 390,014 filed by me on June 18, 1920.

Claims: 1. In an instrument of the character de-v scribed, a standard clock, a synchronous motor, two hands mounted concentrically,

connections between one hand and the standard clock and between the other hand and the synchronous motor, so proportioned that both hands revolve normally at the same rate, and connections between the syn chronous' motor and the driving mechanism ofthe standard c'lockwhereby the spring of the latter is kept constantly wound. p 2. In an instrumentof the character described, a clock movement provided with a main springand with a time element rotatablethereby, a second-time element concentric'ally mounted with relation to the first mentioned time element, 'a synchronous motor, gearing connecting said motor with said second time element, and gearing connecting said synchronous motor with the main spring of the clock .towind up the same.

3. In an instrument of the character (10- scribed, a clock movement provided with a main spring; a time element, and gearing connecting said'time element with said main spring to be continuously rotated thereby, a

;second time element concentrically mounted with relation to the first-mentioned time element. a synchronous motor, and gearing connecting the second time element with the synchronous motor to be continuously driven thereby, and soproportioned with relation to the gearing of the clock movement as to normallyrotate the second. time element at the same rate as the first-mentioned time element whereby variations in the synchronism of the-two motors are instantly visualized.

4. In an' instrument of the character described, a time element, a clock movement provided with gearing connected with said time element to rotate the latter, a second time element concentrically mounted with relation to the first-mentioned time element,

a synchronous motor, and gearing connecting variations in the chronism of the clockthe second time element with the synchronous movement and of t e synchronous motor are motor to be continuously driven thereby, an

d instantly visualized. so proportioned with relation to the gearing In testimony whereof, I have signed my of the clock movement as to normally rotate name to this specification. the second time element at the same rate as the first-mentioned time element, whereby HENRY E. WARREN.

Images