US2447798A - Clock control mechanism - Google Patents

Description

Aug. 24, 1948. H. N. DEANE CLOCK CONTROL MECHANISM Filed 001;. '7, 1944 I INVENTOR. flfnfyfi Deqne.

Patented Aug. 24, 1948 CLOCK CONTROL DIECHANISM Henry N. Deane,

Gardner, Mass, assignor to Simplex Time Recorder 00., Gardner, Mass, a corporation of Massachusetts Application October 7, 1944, Serial No. 557,651

3 Claims. 1

This invention relates to time clocks operated by synchronous motors and relates more particularly to mechanism for resetting secondary clocks of this type to indicate the exact time shown by a master or control clock. The invention also relates to mechanism adapted to reset both the master clock and the secondary clocks after a general current interruption.

To the attainment of these general objects, I have provided. certain control mechanism of simple and effective construction and which is exceptionally well adapted to its intended purposes.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawing which is a diagrammatic view illustrating my improved control mechanism.

Referring to the drawing, I have shown a master or control clock C, and two secondary clocks Cl and C2. While two clocks only are shown in the drawing, it will be understood that any desired number of additional secondary clocks -may be placed in parallel with the clocks Cl and C2.

The master clock C is indicated as having a drive shaft It provided with a ratchet wheel H intermittently advanced by a feed pawl 12 on a feed lever Hi. The lever M has a stud l engaged by a cam 15 on a drive shaft H. A lowspeed synchronous motor M and a high-speed synchronous motor M are connected to the cam shaft ll through differential gearing of any usual type enclosed in a casing H3. The cam shaft It may thus be driven at low speed by the motor M, at high speed by the motor M, or at a still higher speed by the combined action of both motors M and M.

The motor M is commonly designed to turn the cam shaft I! one revolution per minute so that the sixty-tooth ratchet wheel I l is advanced one tooth for each minute and thus makes one revolution each hour.

Each secondary clock CI and C2 is similarly provided with a drive shaft 26 and ratchet wheel 22 and with a slow-speed motor 22, a high speed motor 23, and a differential gear box 24.

The control clock C has a pair of contacts 39 which are normally open but which close when a spring blade 32 drops into a notch 33 in a disc 34 mounted on and rotatable with the shaft [0. A second pair of contacts 46 in the clock C are normally closed but open when a blade 42 drops into a notch 43 in a disc 44, also mounted on the shaft I 9.

Similarly, each secondary clock Cl and C2 is provided with a pair of contacts 5!] which are normally closed but which open when a blade 52 drops into a notch 53 in a disc 56% mounted on its shaft 20.

A three-pole double-throw switch 5 is maintained normally in the raised position shown in the drawing by a spring 55, but is shifted to lowered position by a solenoid plunger 55 when its solenoid 57 is energized. Power is supplied through line wires L and L and the system becomes operative on the closing of a master hand switch 60.

The line wire L is then connected through the switch 50 to the upper blade SI of the switch S and thence through upper contact 62, wire 63 and branch wires 64 to one terminal of the slowspeed motor 22 in each secondary clock. The return circuit is through branch wires 65 and a return wire 66 to the line wire L. The motors of the secondary clocks are thus continuously energized and the clocks are regularly advanced at minute intervals.

At the same time the line wire L is connected through wire 70 and branch wire 1 I to the slowspeed motor M of the control clock C. A branch wire 12 and return wire 13 completes the return to the line wire L, thus continuously rotating the motor M and advancing the control clock at minute intervals through the feed mechanism previously described.

The discs 34 and 44 on the drive shaft I!) are {so set that the normally-open contacts 33 will be closed when the clock C is advanced to the fiftyninth minute, and the normally-closed contacts 1B will be opened when the clock C is advanced to the sixtieth minute. Similarly, the control discs 54 on the secondary shafts 2!) are set so that the normally-closed contacts 58 will be opened when the secondary clocks reach the sixtieth minute.

The notches 33, 43 and 53 in the control discs are of such angular extent that the normallyopen contacts 30 remain closed for a minute interval only, and the normally-closed contacts 433 and 50 remain open for a minute interval only.

- The contacts 40 and 5!] close as soon as the secondary clocks are advanced to the first minute.

The operation for time-correction is as follows: At the fifty-ninth minute, the blade 32 drops into the notch 33 of the disc 44 and the contacts 30 close. The line wire L is then connected through wire 10 and its extension 14 to the upper 3 contact point 3!], and thence through lower contact point 30, wire 15 and branch wire 16 to the solenoid coil 51 which operates the triple pole switch S. The circuit is completed through branch wire 11 and return wire 1-3 to the line wire L.

The plunger 56 is thus actuated to shift the three blades of the switch S downward to engage the lower contacts, and in particular to engage the middle blade 80 with its lower contact 8| which is connected by a branch wire 82 to the wire 15 previously described.

As the contacts 30 are at this time closed, the circuit is now complete from the line wire L through wires in and 14, contacts 30, wires 15 and 82, contact 8i and switch blade 80 to a wire 83 which is connected by branch wires 84 and normally-closed contacts 50 to wires 85 leading to one terminal of each high-speed motor 23. The return circuit is completed to the line wire L through branch wires 86 and through return wires 65 and 66 previously described.

The high-speed motors 23 will thus start in operation at the fifty-ninth minute and will continue to turn the associated cam shafts at their high speed of ten revolutions per minute until the secondary clocks have reached the sixtieth minute, when the contacts Eli-will separate and the high-speed motors will stop. It will also be noted that the low-speed motors 22 were previously stopped when the solenoid 5'! was energized and the switch blade 6| was moved downward away from its upper contact 62. Consequently the secondary clocks will now be stopped at the sixtieth minute, which time will be indicated by each secondary clock.

As soon as the control clock C advances to the sixty minute position, the blade 32 will be raised, the contacts (ill will be opened, the solenoid 51 will be deenergized, and the spring 55 will restore the three blades of the switch S to raised position. All parts are thus brought back to their original or normal running position, and the low-speed motors 22 of the secondary clocks are again started in operation.

I have thus provided simple and efficient mechanism for advancing the secondary clocks to show the correct time of the control clock at hourly intervals, if for any reason one'or more of the secondary clocks has been delayed and has gotten out of step with the control clock.

It sometimes happens, however, that an interruption of current in the line wires L and L will throw the control clock as well as the secondary clocks out of correct time. It is customary to provide a reset unit to take care of such current interruption in a synchronous system. I have indicated a reset device It for this purpose, the specific construction of said device forming no part of my present invention. For present purposes, it may be assumed that the device R comprises a spring-driven or battery-driven clock unit which will operate during the current interruption and which will store up the interval of delay until current is again supplied.

When this happens, a circuit will be completed from line wire L through the reset device R to terminals 90 and 9| connected thereto.

The terminal 90 is connected through a wire 22 to the upper contact 93 of the middle switch blade 80, and thence through wire 83, branch wires 32, contacts 50 and wires 85 to the high-speed motors 23 in the secondary clocks, the return being through the branch wires 86 and return wires 65 and 66 to the line wire L.

the end of the At the same time the terminal BI is connected through the lower switch blade 94 to its upper contact 95 and thence through wire 96, contacts 40 and wire M to the high-speed motor M in the control clock C, the circuit being completed through wires 91 and 13 to the line wire L. The high-speed motors 23 and M are thus all set in operation to advance the clocks for the period of delay stored by the reset device R.

During this resetting period, the low-speed motors M and 22 are also operative, as the blade 6 I is in normal or raised position. When the delay has been corrected, the reset device R cuts out and normal operation only is continued.

It is desirable to suspend the operation of the reset device R for the period of two minutes at hour when the ordinary correcting of the secondary clocks takes place, and for this purpose the contacts 40 are provided.

Assuming that the reset device is in operation and with all of the low-speed and highspeed motors active, the blade 32 at the fiftyninth minute will drop into the notch 33. of the disc 34 in th control clock C, thus closing the contacts 30. This will energize the solenoid 51 which will shift the triple blades of the switch S downward, thus breaking the circuits through which the low-speed motors 22 and the high-speed motors M and 23 had been operated by the reset device R. At the same time, the middle blade 83 engages its contact 8! and operates the high speed motors 23. as usual for time correction. This continues until the secondary clocks reach the sixtieth minute, when the contacts 50 open to stop the high-speed motors 23. When the control clock reaches the sixtieth minute, the contacts 313 are opened to deenergize the solenoid 5i and to restore the reset circuits. But at the same time the blade 42 drops into the notch A3 in the disc 44, opening the contacts 40 and breaking the circuit through the high-speed motor M for the control clock C. The open contacts 52 already hold the high-speed secondary motors inoperative. The low-speed motors M and 22 are now in operation and at the end of the sixtieth minute the contacts M) will close, restoring the motor M to control by the reset device R, and the contacts 50 will close, restoring the high-speed secondary motors 23 to control by the reset device.

The reset device It then keeps all high-speed and low-speed motors in operation until the stored delay period has been made up. The reset device then cuts out, leaving the low-speed motors M and 22 only in normal operation.

In the specification and claims, the reference to fifty-ninth, sixtieth and first minutes is illustrative only to identify successive time intervals, and the corrective apparatus may obviously be arranged to operate at any other successive inter vals in the hour period.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. A synchronous clock system comprising a control clock, a plurality of secondary clocks, a normally-operating low-speed motor and a normally-inoperative high-speed motor effective to drive each secondary clock, a normally-operating low-speed motor and a normally-inoperative high-speed motor eflective todrive the control clock, differential connections between the lowspeed and high-speed motors in each clock, means in said control clock to render the low-speed motors in the secondary clocks inoperative and the associated high speed motors operative just prior to a selected time in each hour for the purpose of correcting the time shown by each secondary clock, means in each secondary clock to stop said high-speed motors when each secondary clock has advanced to indicate said selected time, means in said control clock to start said lowspeed motors in said secondary clocks when said control clock thereafter indicates the selected time, a reset device elfective to render the highspeed motors in both the control and the secondary clocks all operative to drive said clocks at above normal speed after a current interruption and until the stored interruption interval has been made up in said control clock and in said secondary clocks by said high-speed motors, and means to cause the low-speed motors in all of said clocks to operate simultaneously and cumulatively with said high-speed motors during resetting and under the control of said reset device.

2. In a clock system supplied from an alternating current source, a master clock and a secondary clock, said clocks havin normal rate self-starting synchronous driving motors normally energized from such source, and self-starting synchronous resetting driving motors which are normally deenergized but arranged when energized from said source to drive their clocks at several times normal rate, energizing circuits for both secondary clock motors under control of the master clock including synchronizing switch means operated periodically by the master clock and effective during a short clock synchronizing interval just prior to the arrival of said clock at a predetermined time indication and becoming ineifective upon such arrival for opening the circuit of the normal rate motor of the secondary clock and closing the circuit of the resetting motor of the secondary clock, switching means operated by the secondary clock and effective only when said secondary clock is at said predetermined time indication for opening the circuit of its resetting motor, and energizing connections to both resetting motors which connections are independent of the aforesaid master clock synchronizing switch means, said last-mentioned energizing connections including normally closed switching means opened by said master clock during the clock synchronizing interval thereof, and normally open switch means in said energizing when it is deconnections adapted to be closed sired to reset both of said clocks.

3. A clock system comprising in combination with a source of alternating current supply, a master clock and a plurality of secondary clocks, each clock containing a pair of self-starting synchronous motors, one a correct rate motor for normally driving its clock at time keeping rate and the other a resetting motor for driving its lClOCk at several times correct rate for resetting purposes, circuit connections whereby said motors may be connected to and energized from said source of supply, the correct rate motors being normally connected to said source and the resetting motors being normally disconnected from said source, clolck synchronizing circuit control means for synchronizing the clocks at a predetermined time indicating synchronizing position comprising a normally open switch in the energizing circuit to all of the secondary clock resetting motors closed by the master clock during periodic synchronizing intervals, a normally closed switch in the energizing circuit to all of the secondary clock correct rate motors opened by the master clock during such synchronizing intervals and normally closed switches in the energizing circuits of the resetting motors of the individual secondary clocks opened by such clocks when they arrive at said predetermined synchronizing position, and clock resetting control means comprising a normally open resetting switch in the energizing circuit to all of the resetting motors in both master and secondary clocks adapted to be closed when it is desired to reset all of said clocks, said resetting circuit being independent of the aforesaid normally open switch controlled by the master clock but in series relation with the aforesaid normally closed switches in the secondary clocks, and means operated by said master clock for opening said resetting circuit during clock synchronizing intervals.

HENRY N. DEANE.

REFERENCES CITED The following references are of record in the

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