US1491223A - Clock-synchronizing mechanism - Google Patents

Description

April 22, 1924. 1,491,223

T. s. CASNER I CLOCK SYNCHRONIZING MECHANISM Filed Sept. 20, 1922 Z XIII/III Patented Apr. 22, 1924.

UNITED STATES PATENT oFFicE.

rnannnus STEPHENS cAsNEn, or rnam'rmnn, new

CLOGK- SYNGHRONIZING MECHANISM.

1 Application flied September 20, 191252.. Serial No. 589,448.

To all whom it may concern:

Be it known that I, THADDEUS STEPHENS CAsNnn, a citizen of the United States, and residing at Plainfield, county of Union,

State of New Jersey, have invented' certain.

utilized in correcting master or other clocks} by Hertzian waves transmitted through space from a central station at which a standard time piece is located. In my co Finding application Serial No. 4'55,262,'filed arch 24, 1921, is disclosed an-apparatus for synchronizing a master clock with the standard clock at Washington, D. C.,'the synchronizing mechanism associated with the clock being operated by an electromechanical device which is in turn controlled by the wireless signals from the central station. 'The synchronizing means is operated electrically and its controlling switch is closed at the proper instant by mechanism which becomes operative only upon receipt of a predetermined series or codes-of signals, such asthat sent outby the central station at Washington.

This switch controlling device is in reality a code reading apparatus which becomes operative only. upon receipt of the proper sequence of signals. It may be formed in different ways and the present invention has for its object the'provision of a device of this character formed as an attachment which can be connected to a wireless receiving set and a clock having a suitable synchronizing device and by means-of which a circuit through the synchronizing device will be closed and the clock correctedat the exact instant of noon each day.

One embodiment of the invention is illustrated in the accompanying drawing in g which cured thereto, which plate maybe of insulating material if desired or may be of brass :or other'conductin'g metalprovidedthat the various current bearing members of the apparatus are insulated therefrom, so that short circuits do not occur.

- Theswitch controlling the circuit through the synchronizing mechanism of the master or other clock (not shown)- is indicated at S,Ythis switch having two flexible blades 12 and 13 the movement of both of which are I necessary to effect the closing of the switch and the completion of the circuit through the synchronizing device. The switch blades 12 and 13 are of resilient material and are supported upon a block 14 of an insulating substance, the wires 15 and 16 leading from these blades respectively to the clock synchronizing mechanism. In the operation of certain types of electro-mechanical synchronizing mechanisms it is desirable that the switch controlling the same be closed GX-I actly at the time set and then opened immediately so that the clock is corrected and immediately released, and is not retarded by the synchronizing mechanism. The mechanism controlling switch S is of this character, that is, it is designed to'efi'ect the in stantaneous closing of the switch at the proper instant and immediately after to effeet the opening thereof.

The downturned end of switch blade 13 is adapted to be moved to the right from the position in which it is illustrated in Figure 1 to the position'in which it is illustrated in Figure 2 by means of a segmental cam 17 of insulating material, such as fiber or bakelite. This cam is rotatably mounted upon a short shaft 18 supported on the plate 11, the cam being freely rotatable upon the shaft but its movement being limited by means of a pin 19 which works in the circular slot 20 in the cam, this pin being secured in wheel 21 which is also rotatably supported upon shaft 18.

VVhee] 21 is provided the lowermost of which is normally in engagement with a pin or stop 22 projecting laterally from the plate 11, a spring 23 having one end fixed to the wheel and the other end to plate 11 tending constantly to rotate wheel 21 in a counter clockwise direction to this limiting position. The angle subtended at the center of pin 18 by the slot 20 is equal to the angle subtended by eight consecutive teeth of wheel-21 and as this wheel is rotatwith eleven teeth 21 i the cam 17 downwardly to the position inwhich it is illustrated in Figure 2, the switch blade 13 being thereby'moved to the right. lrlovement of wheel 21 through a lesser angle than that subtended by nine teeth will not afiect the movement of switch blade 13 since pin 19 will not contact with the end of slot 20 to move the cam.

Switch blade 12 is rigidly connected by means of a bar 24 of insulating matetial to the armature 25 of electromagnet 26, this armature bein pivotally mounted at 27 on the plate 11. lillectromagnet 26 is in a local circuit 28 which is normally closed, the ma net 26 being therefore normally'energized and switch blade 12 normally in the posi tion in which it is illustrated in Figure 1. Circuit 28 includes, however, the armature 29 of an electromagnet 30, this armature being normally drawn to the right so that its free end is in contact with screw contact 31. A coiled spring 32 retracts armature 29 to break circuit 28 whenever electromagnet is deenergized.

Electromagnet 30 is included in a circuit 33 which .is normally closed and which is controlled by a relay 34 of the :type described and illustrated in my copending application Serial No. 455,261, filed March 24, $19.21. One member 35 of this relay is included in circuit 33 and is normally in contact with adjusting screw 36' so that the circuit is closed. The relay is connected by wires 37 to a wireless receiving set of-any well known type, and is designed and constructed to efiect a movement of member'35 away from screw 36 whenever an impulse is received by the receiving 'set. In other words, whenever an electrical impulse is received by the receiving set electromagnet 26 is" degenergized and 'the' resilient switch blade 12 immediately moves armature 25 to the left to the position shown iii'E-igure 2; Electromagnet 26 is, however, energized as soon as the wireless impulse is terminated.

Securely mounted upon plate 11 are electromagnets 40 which are in a local circuit containing a switch (not shown) operated by the pendulum or escapement of theelock to be synchronized with the standard time piece, this switch being closed once eachsec- 0nd by theclock. Armature 41 pivotally supported vat 42 on plate 11 is positioned to be attracted by magnets 40 each time these magnets are energized and this armature has a horizontal arm to the end of which is pivotally connected a pawl 43 acted on by a spring 44 to normally engage the toothed periphery of wheel 21. \Vhen electromagnets 40 are energized, pawl 43 is raised through a distance equal to that. between successive teeth of wheel 21 and a succession of energizations and deenergizations of these magnets effects a steady advance of wheel 21 in a clockwise direction, a dog 45 normally drawn by a spring 46 against the toothed periphery of wheel 21 preventing return movement of the wheel.

Ten movements of armature 41 will effect the advance of wheel 21 through ten teeth and, therefore, the movement of cam 17 and switch blade 13 to the positions occupied by these members in Figure '2. Further advance of wheel 21 can not take place inasmuch as there are no more teeth to be engaged by pawl 43. If dog 45 and pawl 43 are simultaneously moved by armature 25 to releasewheel 21 after it has been rotated to the full extent of its movement, the spring 23 acts to return it quickly to initial position with its lowermost tooth abutting against stop 22.

The device above described is designed particularly for use in connection with clocks to be synchronized in accordance with the signals sent out by wireless from Washington, as before mentioned. In "this system, signals are sent out at second intervals for the five ,min'utes preceding the noon'hour except that the twenty ninth second of each minute is blank, and also the fifty fifth through the fifty ninth second of each minute, exce'pt'the' lafstcminute, when the fiftieth through the 'fi'fty ninth seconds are blank, the final dash being given on the sixtieth second. I

In the operation of the device thewireless is connected to relay 34 and the magnets 40 are electrically connected to the clock escapement at. least several minutes before the noon signal, either manually or by automatic means. The movement of thependuhim or escapement' causes energization of magnets 40 at second intervals and the pawl 43 tends to advance Wheel one tooth per second, Each secondgdiowever, an impulse is received by the wireless apparatus and magnet 26 is deenergized. This deenerg-ization of magnet 26 results in the movement ofarxnature 25 toward the left through the action of the spring contact blade 12 so that pawl 43 and dog 45 are disengaged from wheel 21 at each second and this wheel therefore falls back again to -starting position. i

At the close of each minute five secondimpulses of the wir eless are omitted, the magnet 26 remains. energized for fiv onds and wheel 21 is advanced five teeth be fore magnet26 is again deenerg ized and the wheel released. During this rotation pin 19 travels toward the bottom of slot 20 but not through a sufficient distance to operate cam 17. When, however, the end of the final minute is reached, magnet 26 will remain energized for ten consecutive seconds and pawl 43 will advance. wheel 21 ten teeth so that pin 19 strikes the lower end of slot 20 and moves cam 17 into the position shown in Figure 2, moving blade 13 to the right. Upon the recei t by the wireless receiving set of the final noon signal magnet 26 is again deenergized, armature 25 moves quickly to the left and spring blade 12 makes a contact with blade 13 thereby closing switch S and actuating the clock synchronizing mechanism. Movement of the armature 25 to the left of. course, throws out pawl 43 and dog 45 and releases wheel 21. This wheel turns rapidly in a counter clockwise direction'and, when pin 19 reaches the u per end of slot 20, moves cam 17 upwardly to allow spring blade13 to move. to the left and to thereby break the circuit through the synchronizin mechanism.

The synchronizing mechan sm 1s, there fore, energized only for an instant and movement of the clock is not interfered with. InFigure 2 the arts are illustrated as they will be at the instant of the final deenergization of the electromagnet 26, contact having been established between blades 12 and 13 and wheel 21 having-been disengag'ed by pawl 43 and dog 45 and ready to start its return movement to operate cam 17 It sometimes happens that, due to thunderstorms or other electrical disturbances,

the noon signals are interfered with and when such disturbances are of considerable magnitude, as in case of summer thunderstorms, the mechanism may fail to catch the noon signal. In such case a wheel having six teeth only instead of eleven may be substituted, so that the apparatus will func tion after five seconds of radio silenoeinstead of ten. This causes the mechanism, whenever the signals are accuratel re ceived, to function five times instead 0. once and to correct the hands at the ends of the 56th, 57th, 58th, 59th and 60th minutes in steadof at the end of the 60th minute, or at noon. only. Thuswhen the conditions are such that the signals are received with difficulty the apparatus has five. chances of operating instead of one only. In this case the energization of magnets 40 begins at min utes before the noon hour.

From the above description the operation of the device will be apparent to those skilled in the art. It may be made as a unit, as illustrated. and attached to clocks of various types having suitable synchronizing mechanism, or may be built into'the clock itself if 'found desirable. It will also be obvious that changes may also be made in the design and arrangement of parts and that-the invention is not limited in its scope to that form herein disclosed by way of example.

Having thus described my inventionwhat is claimed as new and desired to be secured by Letters Patent is:

1. In a device of the class described, in

combination, asupport, a switch on said support and adapted to close and open a circuit through an electromechanicalclock synchronizing device, and means for opening and closing said switch, including a cam, a rotatable member for operating the cam, and electromechanical devices for operating said rotatable member upon receipt of a series of electrical impulses in predetermined sequence,

2. In a device oft-he class described, in combination, a support, a switch on said support, and means for openin and closing said switch including, a cam a apted to contact with' a movable switch member to operate the same, a rotatable member operatively connected to the cam for actuating the same,

a spring for normally turning said rotatable member in one direction to move the cam to inoperative position, an electromechanical device for rotating said rotatable member against the tension of said spring to throw the cam into operative position upon receipt of a predetermined number of electrical impulses, and a second electromechanical device for effecting the release of said rotatable member. 7 a

3. In a device of the class described, in combination, a support, ,a switch on said support and adapted to close a circuit through an electromechanical clock synchronizing device, and means for openingand closing said switch including a cam, a member pivot'ally mounted on said support for operating the cam, and devices for operating said pivoted member upon receipt of a series of energizations in predetermined sequence.

4. In a device of the class described, in combination, a support, a switch on said support and adapted to close and open a .circuit through an electromechanical clock through an electromechanical clock synchr0- nizing devie, and to be separated to open saidcircuit, and means for opening and closing said switch including electromechanical means for moving one switch member toward the other, a cam for moving the second switch member, and electromechanical means for operating said cam upon receipt of a' series of electrical impulses in predetermined sequence.

6. Ina device of the class described, inv combination, a switch having two flexible contact blades and controlling a circuit through an electromechanical. clock synchronizing device, and electromechanical means for bringing said switch blades into contact upon receipt of a series of electrical impulses in predetermined sequence, both blades being individually 'moved for the purpose set forth.

' In testimony whereof I hereunto afiix my 20 signature.

THADDEUS STEPHENS CASNER.

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