US533919A - Synchronizer for clocks - Google Patents

Description

(No Model.) 3 SheetsSheet 2.

H. S. PRENTISS. SYNGHRONIZER FOR CLOCKS.

WITNESSES INVENTOB I ,luw/i W J'Lentg SPtenhss BY A (No Model.) 3 Sheets-Sheet 37 H. S. PRENTISS..

SYNGHRONIZER FOR CLOCKS.

No. 533,919. Patented Feb. 12,1895.

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WITNESSES: INVENTOR: 1451M flQfWW/Zfl' Henry S. Ptenciss,

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UNITED STATES PATENT OFFICE.

HENRY S. PRENTISS, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE PRENTISS CLOCK IMPROVEMENT COMPANY, OF NEIV YORK, N. Y., AND JERSEY CITY, NEW JERSEY.

SYNCHRIONIZER FOR CLOCKS.

SPECIFICATION forming part of Letters Patent N 0. 533,919, dated February 12, 1895. Application filed June 30,1 892. Renewed June 22, 1894. Serial No.5l5, l25. (No model.)

To all whom it may concern.-

Be it known that I, HENRY S. PRENTISS, a citizen of the United States, and a resident of Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Synchron-izers for glocks, of which the following is a specificaion.

My invention has reference to electrically synchronizing clocks having self contained motors, and it consists in certain novel features, whereby slow running clocks are advanced to the correct time at the commencement of the synchronizing period, and fast running clocks are held at the hour, until the exact hour as indicated by the master clock is reached, or until the end of the synchronizing period; all of which is more fully pointed out in the following specification and claims, and illustrated in the accompanying drawings, in which Figure 1 represents a face View, part being broken away, of a secondary clock. Fig 2 is a vertical section in the plane 00 to, Fig. 1. Fig. 3 is a diagram showing the arrangement of the clocks in a system. Figs. 4: to 9 are detail views on a larger scale than the preceding figures, illustrating detail parts and their operation.

Similar letters indicate corresponding parts throughout the several views.

In these drawings the letter C designates one of the secondary clocks, which may embody any suitable motor and movement. In this example, I have illustrated a pendulum movement, in which an is the arbor of the minute hand; P, the pendulum; V, the verge rod; 19, the pallet lever mounted on an arbor 19, and S, the scape wheel mounted on an arborj.

In line with the arbor j, (see Figs. a to 9 especially) and supporting one end thereof, is arranged a stud j, on which is mounted a pinion g which is adapted to slide back and forth thereon, and meshes with one of the gears of the train. The pinion carries a dog a b, one end a of which is provided with a tooth a, normally adapted to engage with one of the teeth of the scape-wheel S for propelling the same. The opposite end I) of the dog is arranged to be engaged, under certain circumstances, by a detent c secured to the frame of the clock. The pinion g is engaged by a forked arm g mounted on a bar g which is guided to move in the direction of its length and is connected to the arm-aturef of an electromagnet M. A spring it normally draws the pinion toward the scape-Wheel, its motion being arrested by a suitable shoulder on the bar g Consequently the tooth of the dog CL 1) is in engagement with the scape-wheel S, and the connection between the latter and the train of the clock motor is established. The detent c is so arranged with respect to the end I) of the dog, that when the secondary clock is at the hour, the said end I) is quite opposite the said detent.

In the example illustrated, I have made use of a scape-wheel which makes one rotation a minute. Consequently at the end of each minute the end I) of the dog is opposite the detent c.

D is a circuit closer, of any suitable construction, but which I have here shown as consisting of a cam-shaped metallic part (I mounted. on the arbor m of the minute hand,

and a part d in the shape of a spring contact arm. Back of this circuit closer islocated a second circuit closer E, consisting of a metallic cam-shaped part c mounted on the arbor m; a part e made of insulating material,

a portion of which projects above the surface of the part c; and a contact arm 6 The circuit closer D is intended to close the circuit in case the secondary clock is slow, and to that end is so set, that the circuit is closed by the same at a short time, say two minutes before the hour as indicated by the secondary clock, and then broken at one minute before the hour as indicated by said clock. The circuitcloser E is intended to close the circuit in case the secondary clock is fast, and to this end it is so set, that the contact arm (2 leaves the insulated part c, and consequently closes the circuit at the hour as indicated by said secondary clock and then breaks the circuit shortly after.

The master clock closes the circuit at one minute before the hour, (exact hour,) and breaks it at the exact hour.

It will be readily understood that when the secondary clock is correct, no effect is protoo I duced on the same by the making and breaking of the circuit at the master clock.

Assuming the case that one 'of the secondary clocks is slow, it will be seen that the circuit is not broken by the circuit closer D, at a minute before the exact hour. Conse quently, when the circuit is closed by the master clock at one minute before the exact hour, the electro-magnet M is vitalized and the dog a b is withdrawn from engagement with the scape-wheel S, and the train is free to move until its motion is arrested by the engagement of part b of the dog with the detent c, which takes place at one minute before the hour, and the hands of the secondary clock indicate this time. The circuit is then broken at D and the clock continues in the usual manner.

Assuming the case that one of the secondary clocks is fast,(the error not to exceed one minute)it will be seen that the circuit is closed at E at a corresponding time before the exact hour, that is to say, it is closed at the hour as indicated by the secondary clock. The circuit at the master clock being closed at one minute of the hour, as before stated, the dog a b is withdrawn as soon as the secondary clock indicates the hour, but, in view of the fact that at that time the end I) of the dog is quite opposite the detent, the train is not permitted to advance, and the clock simply remains idle. The circuit being broken by the master clock at the exact hour, the connection of the train with the scape-wheel is reestablished and the clock resumes its motion at that time.

In Fig. 3 I have shown the clocks arranged in a system, A beingthe master clock; D,1ts circuit closer; O 0 G the several secondary clocks; B, the battery; 10 and 11, the line wires, and I2, 13 and 14s, the several local wires.

Instead of bringing the slow running secondary clock to the correct time at the commencement of the synchronizing period, they may be set slightly in advance of the correct time at this time; then permitted to run in the usual manner, then held until the exact hour, and then released. To this end the circuit closer I), as before, closes the circuit at two minutes before the hour as indicated by the secondary clock, and breaks it at one minute before the hour, but the master clock, instead of closing the circuit at one minute before the exact hour, closes it at, say, sixty-five seconds (more or less) before the hour, so that, as it were, the time at which the master clock closes the circuit overlaps the time during which the circuit closer at the secondary clock is closed. Assuming the case that the secondary clock is correct, it will be seen, that the circuit is closed at D two minutes before the exact hour. The master clock closes the circuit at sixty-five seconds of the exact hour, and consequently the secondary clock is ad" vanced to within one minute of the hour, at which time the circuitis broken at E and the clock again runs as usual, but is actually five seconds fast. Then the secondary clock reaches the hour, as indicated by the same, the circuit closer E closes the circuit and the clock is held at the hour until the circuit is broken at the master clock, at the exact hour. When the secondary clock is slow a like action takes place.

I do not herein wish to restrict myself to any particular means for establishing the connection between the governing member and the train, nor to the application thereof directly to the scape-wheel. Neither doI wish to restrict myself to the duration of the synchronizing periods as here stated, since these will vary with the part of the train to which the connecting device is applied, as well as with the number of times that the clocks are synchronized daily. Neither do I wish to restrict myself to the use of circuit closers, in

preference to mechanical means, or to their application to the arbor of the minute hand, as they could be operated by a faster moving part, and brought into action only at the synchronizing period.

IVhat I claim as new,and desire to secure by Letters Patent, is-- 1. In a clock system, the combination of a master clock constructed to close the circuit at a predetermined period before the hour and to break it at the hour, and a secondary clock provided with a separable connection between two operativeparts of the train, an electro-magnet controlling said connection, a detent for arresting the movement of the train when in a predetermined position, and a circuit closer D operated by the train and set to close the circuit through the electro-magnet in advance of the closing of the circuit at the master clock, and to break it simultaneously with the closing of the circuit at the master clock, substantially as described.

2. In a clock system, the combination of a master clock constructed to close the circuit at apredetermined period before the hour and to break it at the hour, and a secondary clock provided with. a separable connection between two operative parts of the train, an electro-magnet controlling said connection, a detent forarresting the movement of the train when in a predetermined position and two circuit closers operated by the train; the one being set to close the circuit through the electro-magnet in advance of the closing of the circuit at the master clock, and to break it simultaneously with the closing of the circuit at the master clock; the second circuit closer being set to close the circuit through the electro-magnet at the hour as indicated by the secondary clock, substantially as described.

In testimony that I claim the foregoing as my invention I have signed mynarne, in presence of two witnesses, this ant day of June, 1892.

HENRY S. PRENTISS.

Witnesses:

A. FABER DU FAUR, .ln, KLAS H. TEnUs'rUn.

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