US2535214A - Electrically synchronized timing mechanism - Google Patents

Description

Dec. 26, 1950 J. J. KENNEDY ET AL 2,535,214

ELECTRICALLY SYNCHRONIZED TIMING MECHANISM Filed u 13, 1945 '5 Sheets-Sheet 1 1 Fey] l l jiez/enz oms .J'esse .Z'fienzedy 54%673 ivyer Dec. 26, 1950 J. J. KENNEDY ET AL 5 2 ELECTRICALLY SYNCHRONIZE]: TIMING MECHANISM Filed Aug. 15, 1945 s Sheets-Sheet 2 In yew/47:: Jesse .Ifiezzvedy fidert 021470" Patented Dec. 26, 1950 ELECTRICALLY SYNCHRONIZED TIMING MECHANISM Jesse Kennedy, San Bernardino, Calif., and

Robert Olinger, La Salle, 111., assignors to General Time Corporation, a corporation of Delaware Application August 13, 1945, Serial No. 610,500

Claims.

This invention relates to electric clocks and other time controlled instruments of the carry over or sustaining power type wherein the synchronous motor drives the clock only indirectly through the clock spring but synchronizes operation of the clock by direct control of the balance wheel or its equivalent.

One object of the invention isto provide an improved clock synchronizing mechanism.

Another object is to provide improved magnetic synchronizing mechanism which does not interfere with operation of the clock during periods of current failure.

A.further object is to provide mechanism employing a permanent magnet for synchronizing operation of the clock wherein the magnet is au tomatically shifted upon failure of current so as not to interfere with operation of the clock.

A still further object is to restore the magnet automatically to operative position upon restoration of current.

Other objects and advantages and the nature of the invention will become apparent from the following description of an illustrative clock embodying the invention and shown in the accompanying drawings.

In said drawings:

Figure 1 is a perspective view of the clock.

Fig. 2 is a front sectional elevation of the clock mechanism taken on the plane 22 of Fig. 1 and showing the synchronizing mechanism in operative position. i

Fig. 3 is a side sectional elevation taken on the plane 33 of Fig. 2.

Fig. 4 is a fragmentary sectional elevation taken on the plane 44 of Fig. 3.

Fig. 5 is a view similar to Fig. 2 showing the synchronizing mechanism in operative position.

Fig. 6 is a fragmentary plan section taken on the plane 6--6 of Fig. 5.

Fig. 7 is an elevation of a detail of the means foroscillating the synchronizing magnet; and

Fig. 8 is a section of a detent taken on the planet-8 of Fig. 3.

For convenience, the instruments to which the invention is applicable will be referred to as clocks, but it should be understood that the invention is equally applicable to other time controlled instruments.

In the illustrative instrument, a self-starting synchronous motor I0 controls the operation of the balance wheel II or its equivalent by requiring it to oscillate at a frequency determined by that of the alternating current supply, and supplies power to the clock mechanism indirect- 1y by winding the clock spring l2 or other energy storing means. The clock mechanism therefore functions continuously. For convenience the term clock spring will be employed as a generic term to include other energy storing means.

Clocks of this type are regarded as preferable to those wherein the spring driven clock mechanism is idle, i. e. at rest, except during periods of current interruption because of frequent failure of the latter mechanism to start (on current failure) due to static friction, hardening or viscosity of lubricant, etc. In clocks of the type here involved, it has been proposed to maintain synchronous speed by controlling the frequency of oscillationv of the regulator, e. g. balance wheel, by an oscillating permanent magnet operated by a synchronous motor at a frequency determined by the alternating current power supply. However, if the magnet be really effective in controlling clock frequency it correspondingly interferes with clock operation during periods of current failure. I

In the present embodiment of the invention, the regulator is represented by a conventional balance wheel ll driven by clock spring 12 through a conventional clock train (indicated diagrammatically at 20, Figs. 5 and 6) which need not be described since its details form no part of the present invention. The conven tional hairspring on the balance staff I4 is indicated at Hi. The balance wheel is preferably made of some nonmagnetic material such as brass but carries an armature I1, which may be either of soft iron or of some permanent magnet material such as Alnico, in this case in the form of a segmental insert in its rim, which causes the balance wheel to respond to and keep in step with the oscillation of the controlling permanent magnet. The latter which is advantageously made of Alnico, is preferably forked at IE to provide poles which lie on opposite sides of the balance wheel rim (see Figs. 3 and 5) and thereby increase control over the armature I! which in operative position (Fig. 5) lies between the magnet poles and moves in step therewith. The armature I1 is preferably counterbalanced by an appropriate counterweight on the balance wheel (Fig. 2).

Magnet 13 is carried on an oscillating arm l8 pivoted at [9 and preferably made of nonmagnetic material so as to concentrate the magnetic flux on the armature l'i. Arm [8 is oscillated in this instance by a crank pin 2| operating in a slot 22 in arm I8. The crank pin in the present instance is rotated at synchronous speed by shaft 23 driven by synchronous motor Iii through a driving train presently described. The self-starting synchronous motor may be of any appropriate design, that here shown having a core type stator with a single actuating winding. Its shaft carries driving pinion 26% which drives a train of gears 25, 28 and 27 (Fig. 4) (beginnin with gear 25 and ending in gear 2i on shaft 23) designed to reduce speed and to rotate shaft 23 (and thereby to oscillate control magnet is) at a rate pro portional to the synchronous motor speed and corresponding with the proper rate of oscillation of balance wheel ll. Gear 26 is coaxial with gear 25. It will be understood that the tension of hairsp-ring i5 is adjusted so that in conjunction with conventional escapement mechanism indicated generally 26 the balance wheel normally oscillates as nearly as possible at the correct rate. Departure from the correct rate, however, is prevented during normal periods (when current is on) by the oscillating magnet which compels the clock spring to oscillate the balance wheel at a rate determined by the synchronous motor. Since normal frequency of the balance wheel is adjusted as nearly as may be to the correct frequency, there is little tendency for the balance wheel to get out of step with the oscillatlllg magnet.

During intervals of current failure, magnet 13 is automatically shifted'to an inoperative position (see Fig. 2) sufficiently distant from armature i of the balance wheel not to interfere with the frequency of. oscillation of the balance wheel as then determined solely by the conventional regulating mechanism. In this condition the clock will continue to run as an ordinary spring wound clock for a period determ'ned by the capacity of clock spring [2. Ordinarily, the latter need not be more than the ordinary 24-hour type since generally current interruptions are relatively short in duration. In the present case, if necessary, the clock may be. rewound by hand with key 29.

As here shown, the magnet I3 and its oscillating mechanism comprises a unit mounted in a movable frame 39' (pivoted in this case at 31) and movable to. carry magnet is into and out of operative position relative to the balance wheel and armature ll". In such pivoting movement, the terminal gear 2"! of the driving train rolls around gear 28 thereby'maintaning a continuous driving connecti'on. To eifect this operation, the frame pivot 3i is coaxial with shaft 32 of driving gear 25. A springet connected to frame 36 biases the latter to move out of operative relation with balance wheel Ii to the idle position shown in Fig. 2 upon current failure; The driving force exerted by the synchronous motor upon restora tion of ourent is employed automatically to oscillate frame 31! against the tension of spring 33 into operative position (see Fig. 5). Coaxial with shaft but having no driving connection therewith, is a gear 35 meshing with pinion 36 on and connected to shaft 23. Thus rotation of gear 25 on the frame 36 drives gear- 35' through pinionas. Means are provided for resisting rotation of gear 535' whenever the synchronous motor is operating, with the result that the reaction to rotat'on of gear 35 on pinion 36 creates a torque in a clockwise direction (see Fig. 2) suflicient to overcome the biasof spring 33 and move frame 39 withthe-oscillating magnet i3 into-operative relation to the balance wheel H (see Fig. 5). Durng periods of current failure, resistance torotation of gear 535: being absent, the aforesaid torque disappears and spring 33 rotates frame in a counterclockwise direction to move magnet i3 out of operative relat'on with balance Wheel II and its armature (see Fig. 2)

The means for developing the aforesaid torque on frame 30 is here shown in the form of a friction device 38 operating as next described to resist rotation of gear (Fig. 8), which in this case is mounted on a sleeve 39 (flanged at both ends) coaxial with shaft 32 but otherwise free thereon. Whenever current is on and the synchronous motor operates, the friction device 38 resists rotation of sleeve 39 and gear 35. During periods of current failure sleeve 39 (Fig. 8) is free to rotate, in which event the aforesaid torque disappears with the aforesaid results. The friction control means is here shown in the form of an electromagnet, in this case utilizing the field of the stator of the synchronous motor. A portion of the stator flux is shunted through a magnetizable bar 40' connected at its lower end to stator 4| adjacent one of its poles. The opposite end c'ontrols a pivoted armature and pawl 42 mounted on the side of the stator, depressing the armature and pawl (against tension of spring 43) when the stator is energized, to render the friction means operative. to the stator completes the current for the flux shunted through bar 49. In the present case, the tip of pawl 42 engages the teeth of a ratchet wheel 44 (which may advantageously be in the form of an ordinary spur gear)- operatively connected with sleeve 39 by pinion 45 and gear 46. The latter is only frictionally connected tosleeve 3F; and gear 35 by the friction device 38'. The latter is here shown in the form of a curved spring washer which, reacting against one flanged end on sleeve 39, frictionally presses gears 35 and 46 together and against the flange on the other end of sleeve 39 (see Fig. 8). Both of the latter gears may advantageously be made of fiber or other noiseless gear material. Gear 35 is suspended from gear 46 by a spacer to insure against inter-- meshing of gear 35 with pinion 45. Pinion 45 is connected to ratchet gear 44 by shaft 41 on which both are mounted.

The pole 48 of magnet bar 40' is advantageously provided with a shading ring 49 to prevent vibration of the armature under the alternating magnetic field. An adjusting screw 50 carried by bracket 51 limits upward movement of the pawl and armature. The latter fulorums on a bracket 52'.

It is apparent from the foregoing that whenever motor lElis energized the aforesaid electromagnet arrests rotation of gear 43- thereby creating resistance to rotation on gear 35 with the result above described. Upon current failure pawl 42 releases ratchet gear 44 and through it gear 46 allowing magnet 13 to move out of operative position. When thus released from magnet control the clock continues to operate as an ordinary spring driven clock under the sole control of the balance hairspring and escapemerit mechanism.

To neutralize possible interference by magnet I3 with the'balance wheel as it moves away from the ba'lancewheel (at which time the magnet has ceased to oscillate), the control mechanism is provided with an element for giving a supplemental impulse to the balance wheel to insureits continued oscillation, the impulse device is here shown in the form of a light spring pin 53' carried on an arm- 54 projecting from frame 30. When the magnet oscillating mechanism is in The armature being connected operative position (Fig. spring pin 53'lies adjacent to but out of contact with the periphery of balance wheel II. In movement of the pin 53 to inoperative position with frame 30 (to Fig. 2) it passes over the periphery of balance wheel I I giving it a light impulse sufficient to insure continued movement.

Energy is delivered to clock spring i2 or other energy storing means by synchronous motor through an appropriate gear train comprising a series of gears and pinions 55, 56, 51, 58, 59 and 60,- the latter. pinion 60 being in mesh with spring winding-gear 6|. The first gear 55 in the train isin mesh with pinion 63 on the end of sleeve 39 which, as above described, is rotated by motor driving pinion 24.

To prevent stalling of the motor when the spring is wound a slip connection is inserted between the spring and the spring winding means. This is here represented by a conventional slip spring arrangement between the spring and its surrounding winding barrel 65. The latter is rotated by winding gear 6|, at a torque somewhat less than the maximum torque which the motorlis capable of delivering without stalling, the clock spring when substantially fully wound, will slip inside barrel 65.

Pawl 66 and ratchet 6! permit the spring to be hand wound through key 29 on winding stem 84 without disturbing the winding train. Preferably, the mass of balance wheel I0 is made substantially greater than in ordinary clock mechanisms to give it a relatively low oscillation frequency, thereby reducing the oscillation frequency necessary for magnet I3 and its associated mechanism and correspondingly reducing power required for this purpose.

It will be understood that the clock may be provided with appropriate hands H3 if desired but these may be omitted if the instrument be used for purposes other than indicating time.

Obviously the invention is not limited to the details of the illustrative instrument, since these may be variously modified, Moreover, it is not indispensable that all features of the invention be used conjointly, since various features may be used to advantage in different combinations and subcombinations.

We claim as our invention:

1. A clock of the character described comprising, in combination, clock mechanism having an oscillating regulating device carrying an armature, an oscillatable magnet associated with the armature on said device and adapted to act on the armature to control the oscillation of the regulating device, a movable frame on which said magnet is pivotally supported, a synchronous motor for oscillating said magnet at synchronous frequency to cause said timing device to maintain said frequency, and means operative on failure of motor driving current for moving said frame to separate said magnet and regulating device so that the latter is not influenced by said magnet.

2. A clock of the character described comprising, in combination, a, clock mechanism having an oscillatable regulating device and means for oscillating said device, an oscillatable arm, permanent magnet carried on said arm in proximity to said regulating device for controlling the oscillation of the latter, a movable structure to which said arm is pivoted and carrying arm oscillating means, a synchronous motor for driving said arm oscillating means at synchronous frequency, and means operative on current failure for moving said structure out of operative position. .1

3. A clock of the character described comprising, in combination, clock mechanism having an oscillatable regulating device and including means for oscillating said device, anv oscillatable arm, permanent magnet carried on said arm, a movable frame to which said arm is pivoted andcarrying arm oscillating means, said frame being movable to carry said magnet into operative position with said regulating device for controlling oscillation of the latter, a synchronous motor for operating said arm oscillating means at synchronous frequency, and means operative on energizing said motor to move said frame and magnet into operative position for controlling the frequency of said regulating device.

4. A clock of the character described comprising, in combination, clock mechanism having an oscillatable regulating device and including means for oscillating said device, an oscillatable arm, a permanent magnet carried on said oscillatable arm, a movable frame to which said arm is pivoted and carrying arm oscillating means including an operating pinion, a driving gear meshing with said pinion, said frame being movable about said gear axis to carry said magnet into operative position with said device for controlling oscillation of the latter, a synchronous motor rotating said gear to oscillate said arm at synchronous frequency, and means operative on energizing said motor to move said frame and magnet into operative position for controlling the frequency of said timing device.

5. A clock of the character described comprising, in combination, clock mechanism having an oscillating balance wheel carrying an iron armature magnet on its rim, an oscillatable magnet 'having poles adapted to straddle said balance wheel to act on said armature to control the oscillation of the balance wheel, means including a synchronous motor for oscillating said magnet at synchronous frequency to cause said timing device to maintain said frequency, and means operative on failure of motor driving current for relatively separating said magnet and balance wheel so that the latter is not influenced by said magnet. I l

6. A clock of the character described compris ing, in combination, a clock mechanism having an oscillatable regulating device and including means for oscillating said device, a permanent magnet carried on an oscillatable arm in operative relation to said timing device for controlling the oscillation of the latter, a pivoted frame to which said arm is pivoted, crank means for oscillating said arm, a pinion rotatably mounted on said frame and drivingly connected to said crank means, a driving gear meshed with said pinion and coaxial with said frame pivot whereby said gear and pinion remain meshed while said frame is moved to carry said magnet into and out of operative relation with said regulating device, a synchronous motor for driving said gear to oscillate said magnet at synchronous frequency, and means operative on current failure for moving said frame out of operative position.

7. A clock of the character described comprising, in combination, a clock mechanism having an oscillatable regulating device and including means for oscillating said device, an oscillatable arm carrying a permanent magnet for controlling the oscillation of said device, a frame carrying said arm and adapted to move the magnet into and out of operative relation with said device,

means for biasing said frame to move said magnet into inoperative position remote from said device, arm oscillating mechanism including resisting means for creating a reaction opposing the bias on said frame to move the latter and said magnet to operative position, a synchronous motor for driving said arm oscillating mechanism at synchronous frequency, and means for releasing said resisting means upon current failure to permit said magnet to he moved to inoperative position. v

8. A clock of the character described comprising, in combination, a clock mechanism having an oscillatable regulating device and including means for oscillating said device, an oscillatable arm carrying a permanent magnet for controllin the oscillation of said timing device, a movable frame carrying said arm adapted to be moved into and out of operative relation with said regulating device, means for biasing said frame to move said magnet into inoperative position remote from said device, arm oscillating mechanism, a synchronous motor for driving said arm driving mechanism at synchronous frequency, said oscillating mechanism including gear means operated thereby for resisting operation of said oscillating mechanism and creating a reaction counter to said biasing means for moving said frame and magnet into operative position and means for releasing the resistance oifered by said gear means upon current failure to permit said magnet to be moved into inoperative position.

9. A clock of the character described comprising, in combination, a clock mechanism having an oscillatable regulating device and including means for oscillating said device, an oscillatable arm carrying a permanent magnet for controlling the oscillation of said device, a pivoted frame carrying said arm and adapted to move the magnet into and out of operative relation with said device, means for biasing said frame to move said magnet into inoperative position remote from said device, arm oscillating mechanism, a pinion carried by said frame and rotated .by said arm oscillating mechanism, a gear coaxial with said frame pivot and meshed with said pinion and having a friction device rotatable therewith and adapted when held against rotation to resist rotation (of said gear thereby to create .a reaction overcoming said bias and moving said frame and magnet in operative position, a synchronousmotor, for driving said arm oscillating mechanism at synchronous frequency, and releasable meansior holding said friction device to cause said ma net to be moved to operative position.

10. A clock of the character described comprising, in combination, a clock mechanism having an oscillating regulating device and: includ.- ing means for oscillating said device, an oscillatable arm carrying at its end a permanent magnet for controlling the oscillation of said timing device, a pivoted frame carrying said arm and adapted to move the magnet into and out of operative relation with said device, means for bias ing said frame to move said magnet into :inope erative position remote from said device, atmoscillating mechanism, a pinion carried by said frame and rotated by said arm oscillating mechanism, a gear meshed with said pinion and coaxial with said frame pivot, a friction device rotatahle with said gear adapted when held against rotation to resist rotation of said gear to create a reaction force for moving said frame and mag net against said bias into operative position, a synchronous motor for driving said arm oscillating mechanism at synchronous frequency, and an electromagnet means associated with the motor when energized holding said friction device against rotation and releasing the latter when deenerg-ized to permit said magnet to be moved to inoperative position.

JESSE J, KENNEDY. ROBERT OLINGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 233 7100? Poole Apr. 13 1937 2.2%,411 Neurenther July 8, I941 FOREIGN PATENTS Number Country Date 394,965 Great Britain June 22, 1933 845,449 France May 15, 1939

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