US2019768A

US2019768A - Electric clock

Info

Publication number: US2019768A
Application number: US558773A
Authority: US
Inventors: Maryline B Poole
Original assignee: MARYLINE B POOLE
Current assignee: MARYLINE B POOLE
Priority date: 1931-08-22
Filing date: 1931-08-22
Publication date: 1935-11-05
Anticipated expiration: 1952-11-05

Description

l ELECTRIC CLOCK Filed AAug. 22, 1931 Patented Nov. 5, 1935 UNITED STATES PATENT OFFICE ELECTRIC CLOCK ceased, assigner to N. Y.

Application August 22,

6 Claims.

My invention is an electric clock of the type run from a regulated A. C. current. By regulated current, I mean a current whose frequencyis regulated at the power house sothat the average 6 cycles per second of the current is exactly some predetermined number, usually 60.

One of the objects of my invention is a clock of this type which will bridge over a period of no current and so keep up the motion of the clock hands during a short period of interruption to the current` supply. Another object of my invention is t-he provision of a recoil escapement in aclock of this type to the end that the clock will start itself as soon as power is supplied to it, and not have to be started by outside means as is the case of clocks with a detached escapement (for example, a lever escapement) heretofore used.

A further object of my invention is the elimination of the synchronous motor used in clocks of this type and the substitution therefore of a vibrating reed and connections thereto to keep the clock movement in synchronism with the A. C. current.

A further object of my invention is the provision oi' a frequency reducer to step down the frequency of the cmrent to a sub-multiple value and then by means of a vibrating member in step with said reduced current to bring a clock movement in step therewith. The frequency reducing means 30 may be electrical, mechanical or a combination of both, as is most convenient for the particular conditions to be met.

'Ihe above and other objects of my invention will be described in thefollwing specification and set forth in the claims.

Before giving a detailed description of the mechanism of my invention, I will first give a short description of the principles on which it is based. In the preferred form of my invention, I employ a continuously running clock movement, the power to run which may be obtained from the source of regulated current. Alternatively, the clock may be wound by hand or by.

any suitable battery actuated wind. I'he clock escapement is of the recoil type. since as will be afterwards pointed out, I am not concerned that it keep exact time. 'I'he balance wheel of the ciocor the pendulum, as the case may be, is more orless governed as to its time of vibration by a spring or its equivalent. 'I'he other end of this'spring is arranged to be vibrated periodically by an element actuated in step with the current and preferably at some frequency which is a submultiple of the current frequency. for instance,

1931, Serial No. 558,773

one-half or one-third. I have discovered that even if the frequency at which the end of the spring is vibrated is a multiple of the natural frequency of the balance and its spring, the balance will be forced into step. 5 To take a specific case: Assume that the balance of the clock makes three oscillations per second and that the current frequency is 60. Then there is a factor of 20 between the balance and the current. A factor of 5 may be taken care of between 10 the current and the member vibrated by said current and a factor of 4 between the vibrating member and the balance. That is, an electromagnet, excited by the 60 cycle current, vibrates a. reed at a frequency of l2 and the reed' vibrates 15 the end of the balance spring at a frequency of l2 (four times the frequency of the balance system) and thu's keeps the balance, whose frequency is three, in step, both with the reed and the current. By means of this system of frequency reduction. 20 I do not need a synchronous motor and its associated system of gear reduction, and am free also from the concomitant lubrication troubles.

With the help of these preliminary remarks. my invention may be best understood by reference 25 to the accompanying drawing of which:-Fig. l is a diagrammatic drawing of a clock embodying my herein described invention and Fig. 2 is an alternative circuit which may be used therewith. In Fig. 1. for the sake of clearness, the balance 30 and escapement are shown on a larger scale than the remainder of the clock.

In Fig. l, Ill and II are line conductors which supply regulated current. Ihese are connected by wires I2 and I3 to a winding I4 on an electro- 35 magnet I6, having curved poles IB and Il which define an alte ating magnetic eld in which vibrates a reed Il, held by a block I9 in the framework. 'Ihe reed I8 supports a block 20 in whichis a timing screw 2| to adjust the frequency of 40 the reed. The reed I8 also supports an arm 22 to which is secured one end of a balance spring 23 whose other end is fastened to a balance stai 24. A balance 25 is on the stall' 24 and is provided with four timing screws of which two, 26 45 and 21, are shown. The staff 24 is also provided with two

arms

28 and 29 projecting therefrom and alternately engaged by the pins 30 in a crown wheel 3i mounted on a staff 32. The

arms

28 and 29 with the pins 30 will be recognized as 50 forming the well-known verge escapement.

Power is supplied to the wheel 3l in the usual manner by a pinion 33 on the stai 32 engaging a wheel 3l on a stati' I5 having a pinion 36 driven by awheel Il on a stad I8 which carries a pinion 55 89 driven bythe center wheel 4l on a stad Il revolving once an hour. The stall' Il carries a minute hand 48 and a cannon pinion 42 which drives an intermediate wheel ltturning on a stud 45. A pinion 44 on the wheel 4I turns a wheel (not shown) to which is attached the hour hand l1.

Power is supplied to the center )wheel I by a s gear Il meshing therewith; said gear is on a shaft I! to which is attached one end of a mainspring IU mounted in a barrel is fastened the outside end o: the-spring se. said spring is wound to a certain tension, after which the clip starts tol slip in the barrel 52, thereby A preventing. further winding of the spring. 'Ihe barrel $2 is provided withteeth 53 which are driven by a worm 54 on a shaft l5 which carries anism is well known and does not require extend -of the clip El.

ed description. The magnet III is excited by a winding 62 connected by wires 63 and 64 to the line wires I0 and Il.

' From the preceding, the operation of my improved clock will be clear. The line current drives the disc 59 which, by the connecting gears, turns the barrel 52 and winds the spring 5E faster than the running of the clock will unwind the shaft 49. excess wind being taken care of by the slip Driven by the. clock train. the verge escapement 4vibrates the balance 25 at a rate approximately determined, by the spring 23. The reed Il isvibrated by the regulated current and onaccount of its connection-with the end of the balance spring 2l holds the balance 25 in step. Ihus theV hands of -the clock will revolve at a rate determined by the frequency of the regulated current.

In the event the current is interrupted, the

stored power of the spring-SII will keep the clock going until said spring is-run down. When the current is again resumed. the reed Il will pick up its vibration and the balance will be held in step againLwith the error of the .clock that accumulated during a period of no current. However. the periods of no current in the ordinary commercial system are quite rare and of short duration so the time kept by my herein described clock will be practically that determined by the frequency of the regulated current.

In Fig'. 2, I have shown an electrical method of reducing the frequency of the regulated current by means of a multivibrator circuit well-known in the radio art. This device, with an input of say 60 cycles, will give an output of some submultiple of 60, say 6 cycles per second. 'I'he submultiple frequency is held rigorously with the main frequency. The circuits and description for the vmultivibrator may be found in Radio Engineer-' ing Principles, Lauer and Brown, second edition, page 20'8 et seq. McGraw-Hill Book Co. 1928: also in Reception des Signaux Horaires page 68 et seq.. published for the Bureau of Longitudes Paris by Gauthier-Villars et Cle., Quai desv Grands-Augustine 55, in 1924. In the gure, a multivibrator Il is connected to the line wires Il and Il. Conductors 65 and 68 connect the multivibrators 61 with the winding Il of'the magnet Il. In the event of using the circuit shown in Fig. 2, the multivibrator `may reduce the frequency 10 times to afrequencyofathereedilmayreducetimes tz, the inside of which is Y frictionally engaged by a spring clip Il to which'V l departing from the spirit .of

of the balance 25.

It wilLbe obvious that the reduction factor may be distributed 'in any desired manner between the agencies of the multivibrator, the reed. and the l5 balance. It is necessary only that their combined product be the frequency of the regulated current. This property gives a ilexibility to meet varied requirements which my invention may have tn meet.

The reed Il has a large restoring force compared to the spring 23. so that the force of the latter may be swamped in .the force of the former.

' It is also preferable that the reed I8 be polarized which may be done both by` making it a perl5 manentmagnet or providing a permanent mag- 1 netic ileld to polarize it.

-In the following claims, I have used the term "submultiple frequency" by which I mean a frequency which is that of the fundamental divided 20 Vby an integer other than one:i For example, 12 is a submultiple of 60 since it equals 60 divided by 5.

I consider the use of a vibrating reed as a substitute for a synchronous motor in clocks of this kind of great advantage. it is self-starting and has 25 no lubrication troubles.

Many changes and modifications may be made in the' precise structure herein shown without my invention since I claim 1. In an electric clock, the combination of a source of alternating current, an oscillating member, a spring connected to said`-member, a reed vibrating instep with said current. and a connection between said reed and said spring where by said oscillating member is kept in step withsaid current. l

y 2. In an electric clock the combination of a source of alternating current, an oscillating member, a spring connected to said member.- a reedsoJ vibrating in step with said current at submultiple frequency and a connection between said reed and said spring whereby said oscillating member -iskeptinstepwithsaidcurrent.

8. In an velectric clock the combination of a source of alternating current, and oscillating member, a recoil'escapement to drive said' oscillating member. a spring connected to said member a' reed vibrating in step with said current at submultiple frequency and a connection between said reed and said spring whereby said oscillating member is kept in step with said current.

4. In an-electric clock, the combination of a source of alternating current, a reed vibrated by said current, at a certain frequency, a balance 5 5 y having a frequency a submultiple of that of said reed and'means whereby said reed forces saidl balance into step with said current.

5. In an electric clock the combination of a `sc urce of alternating current having a certain frequency. an electromagnet connected to saidcurrent having an amature vibrating at a submultiple frequency, a balance having a submultiple frequency to that of said armature and connections between said armature and said balance 4 to hold said balance in step with said current. i 6. In an electric clock the combination of a source of alternating current, a reed vibrated by said current at a submultiple frequency of said lcurrent, a balance having a sublnultiple fre- 'I0 quency to said reed and a spring having one end attached to said reed and the other end attached"- to said balance.

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