US2420827A - Electric clock - Google Patents

Description

Filed Aug. 14,1944 2 Sheets-Sheet 1 A? IN V EN TOR.

7 JESSE J KENNEDY 7 2 2 v 70 07 BY ATTORNEY.

y 20, 1947- J. J. KENNEDY 2, ,827

ELECTRIC CLOCK Filed Aug. 14, 1944 2 Sheets-Sheet 2 IN VEN TOR. JE55 J KENNEDY ATTORNEK Patented May 20, 1947 ELECTRIC CLOCK Jesse J. Kennedy, La Salle, Ill., assignor to General Time Instruments Corporation, New York, N. Y., a corporation of Delaware Application August 14, 1944, Serial No. 549,381

2 Claims.

The present invention relates in general to electric clocks and more particularly to electric clocks of the impulse type. The main object of the invention is the provision of an electric impulse clock having improved transmission means from the balance wheel to the time indicating means and new and novel circuit closing means.

One of the main features of the invention relates to the manner in which the oscillations of the balance wheel are transformed into substantially continuous rotation of the time indicating means.

According to another feature of the invention, manual manipulation of the time indicating means does not interfere in any way with the continued operation of the balance wheel. In other words the force applied to the clock hands during setting is not transmitted to the balance wheel.

A further feature of the invention resides in the novel circuit closing arrangement whereby the circuit to the electromagnetic means which maintains the oscillation of the balance wheel includes a portion of the means for transmitting the motion of th balance wheel to the time indicating hands. Thus the pressure at the circuit closing contacts is proportional to the force required to operate the clock hands ensuring a firm elec trical contact when the road on the-motion transmitting means is heavy.

Other objects and features and a clear understanding of the construction and operation of the invention may be had from a perusal of the following specification when read in connection with the accompanying drawing, comprising Figures 1 to 6, inclusive, in which Fig. .1 is a sectional plan view of the clock movement taken along the line I-I of Fig. 2;

Fig. 2 is a front elevational view;

Fig. 3 is a side elevational view;

Fig. 4 is a partial top view'showing the balance starting arrangement;

Fig. 5 is afront View of the construction shown in Fig. 4; and

Fig. 6 is a perspective View with some parts broken away showing the relationship and cooperation of the several parts of the motion transmitting mechanism.

In the drawing only so much of the electric impulse clock has been disclosed as is necessary for acomplete and clear understanding of the invention. Thus the dial, the case, and the arrangement and gearing for setting the hands of the clock are not shown since these do not constitute part of the invention and may be of any standard form and construction.

Referring particularly to Figs. 1, 2, and 3 of the drawing, the electric clock movement is supported between the two plates I and 2 which are maintained in parallel spaced relationship by the pillars 3. Mounted between the plates is the electromagnetic structure, designated generally as the reference character 4, comprising the two pole pieces 5 and 6 terminating in pole faces 9 and Id. The other ends of these pole pieces are connected by the core 1 around which is wound the coil 8. The entire magnetic structure is supported on the pillars 3.

Mounted between the two plates is the balance staff I2 which is pivoted at i3 and I5 in adjust.- able pivot screws, the lower pivot screw, as disclosed in Fig. 2, being supported in the bridge I4 formed out of the plate 2. This balance staff I2 carries the balance wheel I I comprising a ring of non-magnetic material supported by the cross piece I6 which is made of magnetic material and serves as an armature for the electromagnet 4. The ends of this armature It cooperate with and are acted on by the two pole faces 9 and I0.

The balance staff also carries the usual hair spring I1 one end of which is connected to a collar on the shaft and the other end is anchored at I8. The timing of this hair spring and the balance system may be adjusted by means of the usual regulator 25 having the downwardly ex.- tending projection I9. This projection i9 has a slot through which the hair spring passes.

The balance staff is also provided with two pallet pins 2| and 23. The pallet pin 2| is made of silver or other suitable electric contact material whereas the pin 23 may be made of brass or other material and carries a piece of insulation 22. These pallet .pins are arranged to engage the teeth of the star wheel 25 which is mounted on shaft 25 extending at right angles to the .balance staff I2. Shaft 25 is mounted on the bracket 2? having an upturned projection 2'5 which carries the pivot for one end of shaft 25 and an arm 23 extending at right angles to shaft 25 which carries the pivot for the other end thereof.

A toothed wheel 31?. is secured to shaft 25 adjacent to star wheel 24. In the preferred embodiment the star wheel 24 has five points and the toothed wheel 32 has ten teeth. The star wheel could be designed to have any desired odd number of points, but the toothed wheel should have twice as manyteeth as the star wheel has points. A click spring 30 secured to bracket 2'! by means of a Screw 3I engages the toothed wheel 32. A

worm 33 surrounds shaft 25 and is secured thereto. Said worm 33 engages a worm wheel 34 that is mounted on shaft 35 and has its bearings in plates and 2.

Shaft 35 also carries the pinion 36 which is in engagement with the gear wheel 31 mounted on shaft 38 journaled in the two movement plates. Also mounted on shaft 38 is the pinion 39 which meshes with the gear wheel 40 mounted on the center shaft 4|. This center shaft has its bearings in the movement plates and 2 and in front of the plate 2 is provided with apinion 61. This pinion is in engagement with the motion wheel 68 mounted on a stub shaft projecting from plate 2 and rigidly connected to the motion wheel pinion 69. The latter engages the hour wheel is mounted on a sleeve surrounding center shaft 4| which sleeve also carries the hour hand 12. The minute hand H is mounted on the end of center shaft 4|.

The center wheel friction is provided by the friction spring 44 retained between gear 49 and the collar 43.

The bracket 2'! previously referred to is insu lated fro-m the plate 2 and the frame of the clock by means of the insulating block 42. This bracket has another arm 28 extending toward and hav ing its end in engagement with the contact plate 85 which is mounted on plate 2 by means of screw 59 and is insulated from the plate by the insulators 60.

Also mounted on the screw 59 and in electrical contact with the plate 65 is a resistor 58, the purpose of which will be explained later. The other end of this resistor which may be of the carbon pile type is connected to the terminal 62 by means of the flat spring connector 6 l. Terminal 62 is mounted on movement plate I and insulated therefrom and is provided with a terminal screw 63 for facilitating the electrical con nection.

Referring now more particularly to Figs. 4 and 5, the rear plate carries an oscillatable arm 52 which is held on the plate by means of the rivet 57. This arm has a curved cam portion 53 normally held against the cam surface by means of the straight wire spring 55. This spring is anchored to the plate I by means of the stud 58. Sleeve or bushing 45 extends through plate I and is riveted thereto and through this sleeve I extremity carries the wire 54 which projects at right angles therefrom. This wire lies adjacent to the balance When the knob 50 is depressed the cam surface 5| acting on the curved end 53 of the lever 52 rotates the lever about its pivot 51, thereby bringing the wire 54 into engagement with the peripheral surface of balance H and rotating it from its position of rest. When the knob is released the shaft 45 and the knob are returned to normal position by the spring 41. This permits the spring wire 55 to oscillate the arm 52 in a clockwise direction about its pivot 51 during which motion the wire 54 gives an impulse to the balance wheel in order to start its oscillation.

The electrical connections to the clock are made at the terminal 52 from one side of the source of power, the other side of the power source being grounded to the framework of the clock. One end of coil 8 is connected to the contact arm 28 by means of wire 66 and the other end of the coil is connected to the terminal post 62 by means of wire 64. The contact arm 28 is in direct e1ectrical connection through bracket 21 with the star wheel 24. Since the balance wheel is grounded to the frame through its pivots and through the hair spring, the circuit to the electromagnet 4 is completed when the pallet pin 2| engages a tooth on star Wheel 24.

It will also be seen that the resistor 58 is bridged directly across the coil 8 in order to reduce the effect of the induced electromotive force When the circuit to the coil is opened.

When the balance wheel is given an initial impulse as described above, the pallet pin 2| rotating in a clockwise direction (looking down upon the Wheel as in Fig. 1) engages a tooth of star wheel 24 thereby completing the circuit to the electro-magnet. The ends of armature H; are thereby attracted to the pole faces 9 and I0 giving an impulse to the balance wheel in a clockwise direction. As soon as pin 2| becomes disengaged from the tooth of the star wheel 24, the circuit to the magnet is opened. The star wheel rotated an additional amount by the click spring 39 seating itself between two adjacent teeth of the wheel 32. This is done so that the tooth which has just been disengaged by pin 2| will not interfere with the return movement of this pin. The star Wheel is rotated a sufficient amount by pallet pin 2| so that the click spring 30 is lifted just over the top of a tooth of toothed wheel 32. The pressure of click spring 3!! on said tooth snaps the wheel 32 forward an additional amount unti1 said click spring seats in the hollow between the tooth just passed and the next adjacent tooth. Since there are ten teeth on wheel 32, the star wheel is rotated by this action onehalf the distance between two of its points to a position where no point is pointing vertically upward (as shown in Fig. 6), so that the pin 2| on its return movement passes over the star wheel without contacting it. However, one of the points of the star wheel is now pointing vertically downward in a position to be engaged by the insulated pallet pin 23 when the balance wheel reverses its direction under the influence of the hair spring. As the balance wheel oscillates in a reverse direction, the pallet pin 23 strikes the lowest point on the star wheel rotating it in the same direction as did pallet pin 2|. The action of the click spring 30 then continues the rotation until a point on the star wheel is pointing vertically upward ready to be engaged by pallet pin 2| when the balance wheel again reverses direction. During the return movement the circuit to the magnet is not closed. Upon the next vibration of the balance wheel in a clockwise direction the circuit to the magnet is again closed giving an additional impulse to the balance wheel, and this operation continues as long as electric power is supplied to the clock.

The relationship of the two pallet pins 2| and 23 and star wheel 24 is clearly disclosed in the schematic drawing, Fig. 6.

From the foregoing explanation it will be seen that the-electric circuit to the magnet which provides the power for maintaining the balance wheel in operation is closed through the transmission from the balance wheel to the hands of the clock. Rotation of the star wheel 24 rotates shaft 25 whereby the worm 33 rotates the worm wheel 34 and the associated shaft. This movement is transmitted through the previously described gearing to the center shaft 4| which is rotated at the rate of one revolution per hour. The minute hand H is mounted on the shaft and therefore revolves at the same rate. Hour hand 12 is revolved at the rate of one revolution in 12 hours through the. reduction gearing previously described. Thus if the load on the transmission is heavy, the contact pressure between the pallet pin 2! and the star wheel 24 is increased, thereby insuring a firm electrical contact at this point.

By means of the worm 33 and associated gearing, the intermittent rotation of shaft 25 is transformed into substantially continuous rotation of the center shaft H and the minute hand of the clock.

Although only one embodiment of the invention has been disclosed in the drawing and described in the specification, it will be apparent that modifications may be made without depart-- ing from the spirit of the invention.

Having described the invention, what is thought to be new and is desired to have protected by Letters Patent will be pointed out in the appended claims.

What is claimed is:

1. In an electric clock, time indicating means, an oscillatable shaft carrying a balance wheel, electromagnetic means for maintaining said shaft and balance wheel in oscillation, a second shaft substantially at right angles to said first shaft and carrying a star wheel, two pallet pins on said first shaft adapted to alternately engage teeth on opposite sides of said star wheel during successive oscillations of said balance wheel whereby said second shaft is intermittently rotated in one direction, and transmission means for transforming the intermittent rotation of said second shaft into substantially continuous rotation of said time indicating means, said means including a worm on said second shaft and a worm wheel operated thereby,

2. In an electric clock, time indicating means, an oscillatable shaft carrying a balance wheel, electromagnetic means for maintaining said shaft and balance wheel in oscillation, a second shaft substantially at right angles to said first shaft, a star wheel on said second shaft, two pallet pins on said first shaft adapted to alternately engage teeth on opposite sides of said star wheel during successive oscillations of said balance wheel whereby said second shaft is intermittently rotated in one direction, one of said pins being insulated from said first shaft, a circuit for said electromagnetic means including the other of said pins whereby said balance wheel receives an impulse during every other oscillation thereof when said other pin engages a tooth on said star wheel, and means for transforming the intermittent rotation of said second shaft to substantially continuous rotation of said time indicating means.

JESSE J. KENNEDY.

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

UNITED STATES PATENTS Number Name Date 1,091,153 Moore Mar. 24, 1914 1,752,446 Marti Apr. 1, 1930 1,964,857 Neumann July 3, 1934 1,965,762 Battegay July 10, 1934 2,008,338 Rodanet July 16, 1935 FOREIGN PATENTS Number Country Date 666,179 France May 14, 1929

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