US1255905A - Electric clock. - Google Patents

Description

-EL H. MESSIMRQ H Ei CLC'.. APPLICMLQH man oms. 1914.

Patented Feb, l2; 1918.

l @SHEETS-Sgen 2.

E. H. MESSiTER.

ELECTRIC CLOCK.

APPLlcATloN FILED ums. 19m

Patented Feb. 12, 1918.

4 SHEETS-SHEET 3.

E. H. MESSITER.

ELECTRIC cLocK.

APPLKCATiON FILED DEC.5. |914.l

Patented F6512, 191s@ INVENTOR and a resident of Brooklyn,

- fication,

UNITED :STATES PATENT oEEioE.

EDWIN H. MESSITER, BROOKLYN, NEW YBK.

ELECTRIC cnocx` To all whom z't may' concern:

Be it known` that I, EDWIN H. MEssrrER, a citizen of the United States of America, Kings county, and` State of New'Yorlnhave invented certain 'new and useful Improvements in Electric Clocks, of which the following is a specipanying drawings, forming a part thereof.

y invention relates to clocks and other chronological instruments and has v,special reference 4to such as are maintained in operation by electricity.

. I am aware that clocks of-theso-called f self-winding type have hitherto been known and in general use. They are provided with electric motors yfor keeping the main-spring under tension or for raising the weight, the spring or weight being relied upon for directly imparting driving' forces to the clock mechanism. AW'hile my invention pertains to chronological devices which are driven by electricity, the device of my invention is of an. entirely different type from those of the prior art to which reference has just been;

made, since I employ and rely directly upon an electric motor for actuating the escapement mechanism.

One object of my invention is-to. provide a simple and `accurate mechanism that shall .avoid the use-of weights, springs and complicated gearing, and operate with very small friction losses and wear.

' Another` object is to provide a clock` of the character above indicated having a direct driving motor which shall act in the dual ca-g pacity of motor and damping device to drive and at the same t1me prevent too rapid movement of the escapement mechanism.

Another object is to provide a motor that` shall consume a very small amount of energy, shall operate with great inherent regularity, andwith a substantially constant or uniform torque; in fact a motor that shall beparticularly adapted to actuate a clock mechanism.

Other objects'and advantages of my in-' vention will be set forth hereinafter,`and in order that my invention may be thoroughly understood, I will now proceed to describe the same in the following specification and then vpoint out the novel features thereof in appended claims.

I Specification of Letters'l'atent.

reference heilig had to the accomv- Patented Feb.1 2,1918.

AppIication filed December 5, 1914. Serial No.,875,5 76.

Referring to the drawings: Figure 1 isa partially sectional elevation of a clock mechanism constructed in accordance with and embodying the driving motor of my invention. -v v' v, A sectional elevation of the same mechai nism, taken on the line 2'2"of Fig. 1,-isy

shown in Fig. 2.

' Fig. 3 is a sectional view taken on the line 3&3 ,of Fig.` 1 and illustratingthe coperation'b'etween the escapement mechanismand the lever which'it actuates.- k

4 vThe same leverfand the coperating escapenent mechanism isshown in another pobeingv broken away to show'the construction in detail. I t Fig. 8 is a view corresponding to Fig. f1, of

a po'rtion of a modified mechanism in which an impulse is imparted to the pendulum once instead ofV twice in each complete cycle.

' Fig. 9 corresponds to'I Fig."- 4 and illustrates the escapement andthe actuating lever which are adapted for usewith the structure of Fig. 8.

Fig. 10 is a detail'view of a contact maker which is a part of the same mechanism.

Figs. 11, 12 and ,13 are `diagrammatic f views which show the diii'erent positions of the armature disk relative to the poles of the' field magnet of the motor and vwhich clearly show the form of the pole faces.

A diagrammatic. view of the circuit/'connections for' the mechanism of Figs. 1, 2, 3 and 4 is shown in Fig. 14 while a similar view of the connections for the mechanism of Figs. 8, 9 and 10 is shown in Fig. 15.

Figs. land 17 are respectively a sectional elevation and a detailed view of a modified motor structure which also embodies my invention.

While I have shown a Denison esca lement 'mechanism which I now consider preferable,

myinvention is not restricted tothe use of any particular escapement and other well known forms may be employed. The escapement per se forms no partof my present invention.

As hereinafter more fully pointed out, the structure shown in Figs. 8, 9 and 10 is'better adapted for use in chronometers and like 1nvstruments which must operate with great prises an escapement wheel 1G mounted Von a shaft 17, a driving motor 18 operatively connected to the same shaft, a pendulum 19, Vand a pendulum actuating lever or fork 20.

The shaft 1T is supported in bearing sleeves Q1 and 22,which are mounted in stationary plates Q3 and 2a and are insulated therefrom by bushings '25 and 26.

The motor comprises an armature 31, and a field magnet Q7 which, as shown, is provided with a winding 28 and has a pair of opposed pole pieces 29-30. The armature 31 comprises a hub 32, a magnetizable disk 33 secured thereto and extending between the pole pieces Ql'and 30. a non-magnetizable rim 31 which is U-shaped in cross-section and provides a circumferential channel in which a portion of the armature winding 35 is supported.` The air gap existing between the pole faces is not uniform` each of the pole faces being eut back as clearly shown in Figs. 11, 12 and 13 to increase the air gap over a portion of thepole faces at one side. The purpose of this arrangement will hereinafter be fully pointedA out in connection with the operation of the device.

Mounted on the shaft 17 in addition to the escapement. 16 and the motor armature is a lantern p inion 36 which meshes witha train 36 of suitable gearing for propeiling the several hands (not shown) of the clock.

Attention is directed to the fact that power is applied to the escapement shaft v1T which operates at a relatively high speed und '1s geared down to the slower moving hands of the clock instead of being applie'd to the slow moving shafts which are geared up to the eseapement shaft and to the faster moving hands according to usual practice. B v this means a large amount of friction in the works is avoided and the clock is improved by increasing its accuracy and reliability.

While other well known forms of escapements may be used. I prefer the three-legged dead-beat escapeinent shown in the drawings. This escapement is provided with a plurality'of triangular projections or driving teeth 37-38-39 which are secured to but are insulated from the body of the wheel; and radial arms or stopping teeth 410-41--42 The fork 20 is pivotally mounted at its upper end by means of a pivot pin 43 and has an enlargement 4a at its lower end which is apertured to form shoulders 4:3 46 A driving pallet 47 is secured to\and is insulatedfrom the shoulder 45 while a driving pallet 48 is secured to and is in electrical contact with the shoulder 46. The location of the fork 2O ,with reference to the escapement wheel 16 is such that the driving teeth 3'1"*-38-39 extend into the aperture 49 of the fork and are adapted to engage the driving pallets 46 and 47 as hereinafter explained. the escapem'ent shaft 17 extending freely through the aperture of the fork.

The fork 2O is also provided with stopping pallets 50-51 which are laterally opposite each other and are adapted to c0- operate with the stopping teeth of the escapement wheel as hereinafter explained.l

As clearly shown in Fig. 7 the magnetizable armature disk 33 is provided with notches so that the armature has the form of a wheel with three arms 54, 55 and 56 and the channel-shaped non-magnetizablc rim 34. The disk armature is wound with three coils 57 '5S-59, each of which extends diametrically across the disk and adjacent to opposite edges of two of the arms which have the form of sectors. Each coil comprises a plurality of turns but has the general form of a semi-circlesince the wires only extend across one of the side faces ofthe disk7 the remainder of the coil beino disposed 'in the channel-shaped rim of the armature. By reference to Fig. 1 it is therefore evident that onlv that portionA of the coil which is adjacent to the flat surface of the disk is influenced by the magnetic lines of force constituting the field existin between the pole pieces 29-30 of the tiel( magnet.

As clearly shown in the diagrammatic view coils vS-,Q isconnected to the armature disk itself. The other terminal of each is insulated from the disk and from the shaft but. is connectech to one of the driving teeth of the. escapement wheel which, as already pointed out, are insulated from the escapement disk and are electrically independent of each other. The arrangement of parts is obviously such that when one of the driving teeth 37-38-39 engages the pallet 18. a circuit will be established with one of the coils of the armature.

Before describing the other modifications of my invention l will set forth the operation of the one already described. Assumof Fig. 14.-, one terminal of each of thel ing that the yparts i ceci-lpg; the positions shown in Fig. 3, thatthe riving tooth. 39 has just finished 'ving an impulseto the pallet47, driving t efork'20 the penduev lum' 19 to the right, andfnthatthe motion of the escapement'vwheel has been stopped bythe tooth 40 engaging the pallet 51: the pendulum will now 'complete its swing to the right and its direction of` motion Will befree to turn. y l

When the escapement Wheel is inthe position shown in ig.

' pieces of the magnetas shown in Figs.. 2

' tooth ll2 engagesthe stop pallet 50'the relai tive positionsof thelield magnet and arma- 'and Il.y The magnet winding 28"is lenergized but there is no current ina-ny ofthe' armature coils. Under these conditions the magnetic field existing between the pole faces attracts the adjacentA sectorsv of the` armature disk tending to draw them into..

the air gap. Inasmuch as theair gap'is greater at the right where the pole faces are cut backthanat the left, the ma etic field is more powerful at the left an con# sequently the disk amature is moved .to the right, or, in other Words, in a clockwise direction (countersclockwise direction as viewed in Fig. 2). This movement of v'the disk armature produces, of coui.se, a cory responding rotation of the escaper'nentwhee-l.

(in a clockwise direction as viewedin Fig. 3),

and the driving tooth 38'engages pallet 48,-

thereby giving the lever and the penduluman impulse to the left. This impulse is produced bythe magneticaction of the mag? net upon the armature the armature coils. i

Therotationof the disk armature and of the escapement will continue until the independently of ture of the motor being as shown in Fig. 12.-v The disk tends to move still fartherr in the same direction by reasonof the same inagl netic action but is prevented at this time from doing so by the pallet50. The pendulum now' continues its swing to the left and on its return stroke the escapement wheel is'again released. lVhen released it turns a little farther in a clockwise direction by the'magnetic impulse as" above indicated and the driving tooth 39 engages Ipallet 48. The field and armature are now Immediately, when contact is made, one of the coils of the arinature is energized and by reason of thecur I y i shown in Figs. 8, 9 'and '1 0 to which refer# as shown in Fig. 13.

rent transversing the coil a new impulse is imparted to the disk in the'same direction 3, the, armature. disk- 33 is in the position relative to the-'pole' :of eachk coil is influenced'l b r.ing thev coils, thedireetion of in whichftliey are shown in Fig. 3, except .that another driving tooth has taken the position occupied by the tooth 39. The cycle is repeated aslong as current is supplied ."It isevident that Vif thearmature coil were notenergized there would be no 4tendency for the armature to move in th'e same direction after the rst impulse, but the-coil is pdesigned andfwound so that when it is energized vthe influence of 'the magetic ifield upon itis vstronger than the influence of the field upon the adjacent magnetizable arm...

of the armature and `is exerted so as to iinypart ,another-impulse in the same direction, 4vto the armature.

The 'circuit--jconnections may be traced able source of ener-gy` to field magnet winding28 through a conductor' 91,'circuit being` completed through conductor 92 tothe op; posite terminal of the'battery. ofthe driving teeth of the escapement,l as

)for example ,the tooth 38 engages the drivjing`pallet48a motor circuit is temporarily .I completedfrom the conductor 91,.'through a branch 93, bearing sleeve 22, shaft 17, arma- .ture disk 33, armature coil 59, conductor 94,

tooth 38,,pallet 48, fork 20 and pivot pin 43 whichis connected to the frame23 and to conductor 92. The coils are-so wound andformed that only; a single radialsection y the field of force at vone time .and by `suitably connectmotion is alwaysclockwise.

lthe resulting ioo l By slightly modifying the actiiatin'g'lever l 20 as shown in Figi 6, byadding theretoga light resilient contact ,member '60, they-apl paratus may be made self-starting- 'The re-i silient contact is substantiallyUshaped` and is attached to the lever within the aperture 4 9 and extends just into the y of the driving teeth 37-38-f39 and insuch position that whenever the clock is stopped path of .travel Aand the pendulum and leverjcome'to rest in` a centralposition one ofthedriving teeth' will enga-getlie spring and thereby bein 'position to completea 'circuit through one of the` armature coilsas :soon as 'energy is supplied to the vreceiving circuit of thefclock, This feature is particularly valuable for'.

large clocks'orsuch asini'e located kwith their worksv in' a relatively inaccessible position or with their-.axis secured-.to a rigid base so that the pendulum cannot readily be started 4vby hand ,0I-'by tilting thewhole clock..

Another modification-of niyinvention vis ence may now be had. y

Forv particularly laccurate time keeping, it is desirable to insure that a uniform im- CIK its

pulse be imparted to the balan ce Wheel 'or pendulum so that less reliance 1s placed'on e" e isochronism of these parts. By making mplitude o1 every oscillationl is the e and consequently the oscillations will made in more nearly equal periods of inne.

In the embodiment of my invention dis- .ised in 1 to 7 inclusive, the impulses imparted to the pendulum were alternately dependent upon magnetic attraction, and an electro-dynamic expulsion. The impulses exerted by the electro-magnetic attract-ions are inherently more accurately uniform and regular thanare the impulses which are dependent, not only on the strength ot' the magnetic field but also upon the form and location of the armature coils and the our rent traversing one of the coils at any given instant. I have accordingly in the modificat ion of my invention which I will describe in detail hereinafter. utilized only the electrtrruagnetic attractive impulses flor transmitting the motion to the pendulum and 'have utilized the electro-dynamic impulses merely for the purpose of moving the disk armature into a position for the next magnetic impulse to be effected. lVith this arrangement it is therefore obvious that the pendulum will always receive an impulse in the same direction instead of being propellcd alternately in opposite directions: in other words, the pendulum receives an impulse once in each complete cycle instead of twice in each complete cycle of its movement. In order to avoid, to an even greater y extent the possibilities of error, a permanent magnet may be utilized instead of the electro-magnet shown in the drawings for producing the motor eld.

This arrangement secures the advantages of the gravity or remontoire escapement, generally used in astronomical clocks as well :is those pertaining to the semi-independent escapement commonly used in marine and other chronometers.

Corresponding parts are designated by the same reference characters as those employed in theprevious ligures. The bearing sleeves 2l and 22 are not in this case insulated from the stationary supporting plates 23 and 24C and the coils of the disk armature instead of being connected to the driving teeth 37-38-39 of the escapement are respectively connected to a plurality of projecting pins 61-62-63 which are insulated from and extend laterally from a disk 64 and are successively engaged by a relatively stationary yielding contact finger 65 (see Figs. 10 and 15). The disk 64 is secured to the shaft 17 adjacent to the disk armature or at some other convenient point, and in fact the pins can be mounted on the armaimpulse equal to every other impulse ture itself if desired. The pins correspond in number and location to the driving teeth of the escapement. The pendulum actuating lever 20a, as shown in Fig. 9, has only a. single driving pallet 47 `which is not insulated from the lever and receives a driving impulse once for each complete cycle of the escapement wheel instead of a driving.

movement. The free movement is such as to bring the next sector of the disk armature into position to be attracted by the field magnet.

Still another modification of my invention is shown in Figs. 16 and 17 of the drawings.

Referring to these figures the structure here shown comprises a disk armature which is similar to the disk 33 of the motor already described. It has no armature winding and consequently the non-magnetizable rim is superfluous. Instead of a single field magnet, it is provided with a permanent magnet 70 having pole pieces 71 and 72, and an elec tromagnet 73 which is located on the opposite side of the disk axis and has pole pieces 74 and 75. Each pair of pole pieces corresponds in form to the pole pieces 29 and 30 of the motor 18.

The Winding 7 6 of the electro-magnet, instead of being constantly energized is controlled by a circuit closer and is periodically energized.

The circuit closer may be comprised of the escapement wheel driving teeth, coperating with one of the driving pallets of the pendulum lever, or a separate circuit closer, as for example the circuit closer 7S, may be provided. This device is similar to the circuit closer 6e of the previous figures and need not be described again in detail.

The operation of this motor is as follows: Assuming that the electro-magnet is deenergizcd, the permanent magnet produces a 60 degree advancement of the escapelnent wheel. This stroke draws one of the iron segments of the disk armature into the air gap of the permanent magnet. In this posi tion, the circuit closer completes a circuit through the coil of the electro-magnet and thereby another forward movement of the armature is produced, the electro-magnet being arranged to exert suiiicient force to overpowcr the permanent magnet. The action of the escapement `wheel in imparting impulses to the pendulum is the same as hereinbetore described.

The permanent magnet may be replaced by a second electro-magnet which may then beA energized in alternation with the first, but I prefer to `use the permanent magnet and utilize its impulses for driving the pendulum or balance wheel of the clockv for the sake of uniformity of action.

The electro-magnets may be made to operate with a high degree of accuracy by designing the magnetic circuit to operate over the knee of the saturation curve where variations in the magnetizing currents have a very small effect upon the magnetic field.

The lower end of the fork 20*t may be entirely cut away in the form shown in Fig. 9 ifdesired, as only a single driving pallet is use j It is evident that various structural modifications may be effected within the spirit and scope of my invention and I intend that only such limitations be imposed as are indicated in the appended claims,

What I claim is: i

1. An electrically propelled clock cornprising an isochronous vibrator, an escapement, a driving shaft-therefor, and an electric driving motor connected to directly act upon said shaft. i

2. A clock comprising an escapement, a driving shaft therefor and a motor havin an armature directly attached to said sha arranged to impart a succession of rotative l ing an escapement and a rotary motor impulses to the shaft. f.

3. A clock comprising a pendulum, an escapement, a driving shaft therefor and an electric motor arranged to imparta succession of rotative impulses to the shaft, and means for controlling the periodicity of thel motor impulses.

4. A clock comprising a pendulum, an escapement,`a driving shaft therefor and an electric motor arranged to im art a succession of rotative impulses to t eshaft, and means dependent upon the escapement for controlling the periodicity of the motor impulses.

5. A clock comprising av'pendulum, ai, resi capement, a driving shaft therefor, and an electric motor adapted to impart a suc ession of rotative impulses te the shaft and comprising a field magnet, a disk armature, armature coils therefor, and means dependent upon the escapement for controlling energization of the coils.

(3. A clock comprising a pendulum, a pendulum fork, an escapement having a plural- I' ity of electrically independent driving teeth, a driving shaft for the escapement, anelectric motor mounted on the shaft, and coils for the motor adapted to be successively energized in'response to the coperative action of the escapement and the pendulum fork.

7. A clock comprising a pendulum, a pendulum fork having driving pallets, a source of electric energy connected to one of the driving pallets, an escapement comprising a plurality of electrically independent driving teeth, a driving shaft for the escapement, an electric motor mounted on the shaft and having a plurality of armature coils respectively connected to the driving teeth of the escapement, the opposite terminals of said coils being connected to the source of electric energy.

8. A clock comprising a pendulum, a pendulum forkhaving driving pallets, a source of electric energy connected to one of the driving pallets, an escapement comprising a plurality of electrically independent driving teeth, a driving shaft4 for the escapement, an electric motor comprising a field magnet adapted toproduce Ia constant magnetic field, a disk armature mounted on the shaft an'd arranged to cut the magnetic field, a plurality of coils extending diametrically across one face ofthe disk armature, a nonma-gnetizable circumferential support in which `the remainders of the coils-are mounted, said coils being electrically connected at one end to the said source of energy and at their opposite ends to the respective driving teeth of the escapement, whereby the coils are successively energized as the driving teeth make contact with the electrically active driving pallet.

9.An electrically propelled clock comprisadapted to operate at substantially,- the speed of the escapement and connected to drive said escapement.

driving shaft therefor and an electric motor arranged to impart succession of rotative impulses to the shaft, and means dependent upon the escapement for controlling the periodicity of the motor impulses.

11. A clock comprising an escapement, va driving shaft therefor, and an electric motor adapted to impart a succession of rotative imp ulses to the shaft and comprising a field magnet, a disk armature, armature coils therefor, and means dependent upon the escapement for controllingenergization f of the coils.

l. ico 10. A clock comprising an escapement, a

Sion of uni-directional impulses are impart-- ed to the shaft, and means dependent upon the escapement for controlling the periodicity of the motor impulses.

14. A clock comprising an escapement, a

driving shaft therefor, an electric motor comprising means tending to exert e succession of rotative lmpulses to the shaft alternating in direction, and electro-responsive means controlled by the ,escapement for counteracting alternate impulses whereby a succession of unidirectional impulses are imparted to the shaft.

In Witness whereof I have hereunto set iny hand in the presence of two subscribing 15

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