US2241447A - Clock synchronizing device - Google Patents

Description

May 13, 1941. E. A. DEMONET CLOCK SYNCHRONIZING DEVICE Filed Sept. 28, 1938 2 Sheets-Sheet 1 a m a 3204 E li-Fig" INVENTOR E. A. DEMONET A TORN Patented May 13, 1941 UNITED STATES PATENT OFFICE CLOCK SYNCEIONIZING DEVICE Eugene A. Damonet, East Orange, N. 1., assignorr to'lliewclternllnion'lelegraphampalmliew YorkJLY acfNewYork Application September- 28. 193 Serial No. 232,065

claims. CI. 58-34) This invention relates to clock synchronizing devices and has particular reference to a manual means for setting clocks having hands to which the driving force is transmitted by means of a clutch.

Heretofore, clocks were provided with mechanisms whereby the hands might be set to any desired position on the dial and thereby synchronized with any convenient standard. However, with such devices, the engagement of a'setting member was usually required and a visual observation of the setting operation was always necessary. Hence, the accuracy of the synchronization depended upon the mechanical skill of the operator, his ability to avoid parallax in viewing the dial and his capacity to estimate the elapsed time between his perception of a standardizing signal and the completion of the setting operation.

Standardizing signals are now available exactly on every hour and, in many instances, also on every half hour. One form of signal commonly employed for synchronizing purposes is a distinctive tone transmitted over radio channels from a large number of broadcasting stations and may be obtained by any suitable arranged radio receiving set.

Since clocks are generally utilized for the observation of the correct time, they are located where they may best perform this function. To this end, clocks are frequently displayed in show windows, in elevated positions on walls and in numerous other relatively inaccessible positions. Clocks so disposed are not susceptible of expeditious and accurate synchronization by prior art means which require, among other things, a clear view of the dial during the setting operation.

Hence, it is an object of this invention to provide a clock with means for obviating the above enumerated difliculties.

It is another object of this invention to provide means whereby the hands of a clock may be set substantially instantaneously to any one of a plurality of predetermined positions.

Another object of this invention is to provide means whereby said aforementioned setting device may be actuated from a point remote from the clock.

A further object of the invention is to provide means in a reciprocating clock setting member for simultaneously restoring any alarm or signal device to its normal position.

Still another object of the invention is to provide a means for attaining said aforementioned objects which may be inserted in an existing clock with a minimum of alteration thereof.

Although the invention will be described in conjunction with a clock the hands of which are driven by means of a synchronous electric motor of the self-starting ype. it is contemplated that such a combination be considered as merely illustrative. It should be obvious to those versed in the art that the present invention may be used with equal facility on other types of clocks including those which are spring or weight driven. Accordingly, the following description is taken in conjunction with the accompanying drawings, of which:

Fig. 1 is a front or face view of the clock embodying the invention;

Fig. 2 is a partial side view drawn to an enlarged scale and broken away to show some of the clock mechanism;

Fig. 3 is a view taken on the line 3-3 of Fig. 2 and with the case removed;

Fig. 4 is a view similar to Fig. 3 of a modification of the invention;

Fig. 5 is a view taken on the line H of 4;

Fig.6lsaviewtakenontheline Hofl 'lg. 4;

Fig.7isaviewsimilartothatofFis.3 ofanother form of the invention;

Fig. 8 shows the instrumentalities of Fig. 'l in their operated positions;

Fig. 9 is a view similar to that of Fig. 3 of another modiflcation of the invention; and

Fig. 10 is a side view of the device illustrated in Fig. 9 and shows the details thereof in their relations to other parts of the clock.

Having reference first to Fig. 1, there is shown in front elevation a clock having a dial II and hands l2 and I3 mounted in a case it. Projecting from the underside of the case M is a knurled knob or thumb screw IS with which the hands I2 and I! may be set by a rotating movement thereof. An arm i6 is also extended to a point on the exterior of the case M.

The following portion of the description is taken with reference to Figs. 2 and 3. The mechanism for driving the hands I! and I3 is disposed behind the dial II, and that portion of the mechanism comprising the gear train is supported between the plates I1 and it. These plates are spaced a suitable distance apart by means of a plurality of sleeves I9, 20 and 2|. A synchronous motor 22 drives the gear train by which a suitable speed reduction is obtained whereby the gear 23 is driven at the rate of one revolution per hour. The gear 24 is securely fastened to the shaft 25 at the extremity of which is mounted the minute hand I2. Interposed between the gears 23 and 24 is a clutch by means of which the rotary movement of gear 23 is transmitted to gear 24 and thereby drives the minute hand over the dial of the clock. Gears 26, 21 and 28 form a unitary structure and gear 21 is arranged to mesh with the minute hand gear 24. Gear 26 is arranged to mesh with the hour hand gear 29 which is secured to a shaft 33 carrying the hour hand I3 of the clock. The minute hand gear 24 has inserted in the front face thereof two short pins 3I which are located on a diameter of the gear 24. The minute hand I3 is placed on the shaft 26 so that it points at the numeral XII inscribed on the dial I I when the minute hand gear 24 is in such a position that the pins 3| are horizontally disposed.

A thin elongated plate 32 is mounted immediately forward of the minute hand gear 24. As may be seen more clearly in Fig. 3, this plate 32 is provided with a'generally rectangular opening 33 at the central portion thereof. The upper side of the opening 33 is horizontal and has an arcuate groove 34 formed at the center thereof. The lower part of the opening 33 is somewhat narrower and is adapted to permit the gear 26 to extend through the plate. The width of this lower portion of the opening 33 is slightly greater than the maximum diameter of the gear 26 so that the plate 32 may be freely moved up and down with respect to the gear 26 which is instrumental in preventing sidewise movements of the plate. A portion of the upper left hand corner of the plate 32 as viewed in Fig. 3 is cut away to provide a shoulder 36 which abuts the spacing sleeve I9 and thereby limits the upward movement of the plate 32. The formation of this shoulder also provides a longitudinal edge 36 which also abuts the sleeve I9 thereby limiting the sidewise movement of the plate 32 toward the left. At the top of the plate 32 is also privided a lug or ear 31. A spiral spring 33 is coiled about the spacing sleeve I9 and is attached with one end in engagement with the top of the plate l3 and the other end in registry with the under side of the lug 31. The effect of the spring 33 is to urge the plate 32 in an upward direction and at the same time toward the left so that the edge 36 is maintained in sliding contact with the sleeve I9.

The plate 32, being thin and located in a plane parallel to the planes of the various gears, is

adapted to be moved up and down. Its normal position which is maintained by means of the spring 38 is up as shown in Fig. 3. However it may be moved downward against the force of the spring 33 by depressing the L-shaped operating lever I6 attached thereto. The manner in which this downward motion effects the setting 01'. the hands is as follows. Let it be assumed that the hands I2 and I3 are disposed so that they indicate a time corresponding to a few minutes before the hour of six. In such a position the pins 3| which are carried by the minute hand gear 24 are disposed at an angle as shown in this figure. If at this time it be desired to set the hands of the clock so that they point directly to the numerals XII and VI respectively on the dial, the plate 32 is depressed by means of the lever I6 and the upper edge of the opening 33 engages one of the pins 3I. Further movement of the plate 32 imparts a rotative movement to the gear 24 whereby, at the bottom of the stroke, the pins 3I will be disposed in a horizontal position and the hands of the clock will point directly to the numerals XII and VI. It will be noted that the arcuate portion 34 of the upper edge of the opening 33 is for the purpose of avoiding contact between the plate and the shaft 26. Upon the release of the member I6, the plate 32 is restored to normal by means of. the spring 33.

Because of the relation of the minute hand gear 24 and the hour hand gear 29 through the reduction gears 26 and 21, the resetting motion which is imparted to the gear 24 by the plate 32 is also transferred to the gear 29. It will be obvious that the device comprising this invention will also effect the setting operation when the minute hand I2 is located in a position past the exact hour position. It also will be noted that the hands of the clock may be reset to the exact hour when their positions indicate any time within the range between approximately ten minutes before and ten minutes after any exact hour. Also the disposition of the pins 3I is such that the hands may be set to the exact half hour from any point within a corresponding range.

The present invention may also be used in cooperation with any of the conventional types of resetting devices. One such device is shown in Fig. 2 and comprises a vertical shaft 39 carrying at its lower extremity the thumb nut I6 and mounted in a bracket 43 which is attached to the rear supporting plate I3. The shaft 39 carries at its upper extremity a horizontally arranged gear 4| and is arranged to be slidably moved up and down in the bracket 43. The shaft 39 is normally held in its upper position by means of a compression spring 42 which is attached to the shaft by a collar 43 and is arranged to engage the lower portion of the bracket 40. In this position the gear H is disengaged, but upon the depression of the shaft 39 it is brought into engagement with gear 23. A rotative movement which may be applied to the shaft 39, while being held in its depressed position, will cause rotation of the gears 26, 21 and 23 and thereby effect a movement of the hands I2 and I3. By means of such a resetting device the hands may be placed in any desired position and it will be noted that the movements of the shaft 39 and the plate 32 are entirely independent of one another. Upward movement of the shaft 39 is limited by the engagement of another collar 44 attached thereto with the lower part of the bracket 43.

It is customary to provide synchronous electrically driven clocks of the self-starting type I with an indicator or alarm signal for the purpose of indicating that some abnormal condition exists or has existed. For example, if the current supply for the electric driving member is interrupted for substantially any period of time, the indicating device will be actuated and will remain in its actuated position until manually reset. An electrically driven clock having such a device is shown in Figs. 4, 5 and 6. A shaft 46 having its ends journaled in the plates I1 and I3, carries adjacent its forward end a sector-shaped disc 46. The front surface of this disc is divided into two parts, one of which 41 is preferably colored white and the other of which 43 is preferably colored red. A circular opening 49 is provided in the plate I1 in front of the disc 46 and a similar opening is also provided in the dial of the clock whereby the face of the disc 46 may be observed. In its normal position, indicated in Fig. 4 by the full lines, the white portion 41 of the disc face is visible through the openings. When the indicating device is in the position shown by the dotted lines, the red portion 43 is visible.

The movements of the disc 46 are controlled by a member mounted adjacent the rear end of the shaft 46. This member comprises a plurality of arms or fingers extending radially from the shaft in such a manner that the center of gravity of the complete structure mounted on the shaft 46 lies to the left of the pivot point as viewed in Fig. 4. In the absence of any restraining infiuence, the disc 46 is moved by the force of gravity to its dotted position. However, when potential is applied to the field coil 60 of the synchronous motor the core 6| and the extended screw 62 become magnetized. When the indicating device is restored to its normal position one of the plurality of arms 63 which is provided with an angular projection 64 is brought into proximity with the screw 62. The arm 62 being of magnetic material, the device is held in this position magnetically as long as the coil 60 is energized. when the energization of this coil is interrupted for even a short time, the attraction for the projection 64 is removed and the disc 46 is carried to its dotted position under the influence of gravity.

A bell crank having a long arm 66 extending upwardly and a short arm 66 extending horizontally is pivoted at the juncture 61 of said arms on the rear plate Ill. The horizontal arm 66 is arranged to bear against the -under surface of the resetting gear 4|. The outer edge of the long arm 66 is arranged to bear, adjacent its upper extremity, against a projection 66 extending forwardly from the plate I 8. A wire spring 66 is coiled about the pivot point 61 and one end thereof placed against the under side of the spacing stud 20. The other end of the spring 69 is extended upward and has a loop formed therein which is placed in registry with the inner or left hand edge of the long arm 65. The purpose of the spring 59 is to hold the bell crank in the position shown. The inner or left hand edge of the upper portion of the long arm 66 is arranged to engage another arm 6| of the indicating device. When the device is in its lower or dotted position a projection on the arm 6| is brought into registry with the upper end of the long arm 55. When the hands of the clock are reset by means of the conventional shaft 39, the downward movement of the gear 4| carries with it the extremity of the short arm 66. This movement causes the upper end of the long arm 66 to be moved to the left to the position shown dotted. Thus the finger 6| is rotated in a clockwise direction, thereby restoring the indicating device to normal, in which position the projection 64 comes within the influence of the magnetized screw 62.

A thin plate 62 which is substantially similar to plate 22 on Fig. 3 is also provided as a means for resetting the hands of the clock and at the same time for restoring the indicating device to normal independently of the mechanism described hereinbefore. In addition to the details for resetting'the hands of the clock, plate 62 is provided with an extension 63 having at its extremity an angular portion 64. This extension 64 is so disposed that when the indicating device is in its abnormal or alarm position and the arm 63 is raised to the position shown dotted, an engagement is effected between the angular extension 64 and the arm 63. Also the plate 62 is provided with a rod or plunger 66 attached to the upper part of the plate 62 and extending upward through the clock case l4 and carrying at its extremity a button 66. When the button 66 is depressed the plate 62 is carried downward and the hands of the clock are set as previously described. Simultaneously. the arm 63 of the indicating device is restored to its normal position by the downward movement of the extended arm 64, whereby the projection 64 is disposed adjacent the screw 62.

Another form of the invention is shown in Fig. 7 wherein the minute hand gear 24 is provided with a single pin 61 which is larger in diameter than the minute hand shaft 26. As in the modifications previously described, this pin projects forwardly from the minute hand gear. The means for actuating this gear to synchronize the hands is a plate 68, the upper portion of which is guided by the spacing sleeve IS in the manner previously described. However, the lower portion of the plate is not dependent upon the gear 26 for support or guiding. This lower portion is in the form of two legs 69 and II, the outer edges of which are arranged to engage the spacing sleeves 20 and 2i, respectively. Plate 68 is normally urged upward by the action of the spring 36 and, in the form shown, is arranged to be depressed by the application of pressure upon the button 66. However, it should be obvious that suitable arrangements may be made whereby the plate is actuated by being drawn or pulled to its lower portion. The upper part of the recess formed between the legs 69 and II is characterized by two substantially horizontal edges 12 spaced apart by the width of a second recess 13. The recess 13 is wide enough to permit passage of the plate 66 over the minute hand shaft 25 and yet is narrow enough to prevent the entry of the pin 61 thereinto. The junctures of the edges 12 with the vertical portions of the recess 13 are given beveled configurations.

The operation of the synchronizing device is as follows. The plate 68 is moved downward under pressure applied to the button 66 whereby one of the edges 12 is brought into engagement with the pin 61. Further movement of the plate causes the pin to be rotated about the axis formed by the minute hand shaft 25 whereby the minute hand gear 24 and the minute hand l2 are given a rotative movement. Just prior to the attainment of the synchronous position of the hands l2 and I2 one of the beveled portions of the plate 66 effects engagement with the pin 61. It will be noted that at this position the torque which is applied to the pin 61 by the edge 12 is small, but by applying the pressure to the pin through the beveled portions a substantial increase in the torque tending to rotate the gear 24 and the hand I2 is eflected. Also, it may be seen by reference to Fig. 8 that upon the attainment of the synchronous position the beveled portions of the plate 68 afford a secure and positive seating for the pin 61. It should be obvious that the synchronizing operation may be effected in cases where it is desired to move the hands backward with equal facility since the instrumentalities provided therefor are symmetrical with respect to the center of rotation.

Such an arrangement permits the synchronizing of the clock at but one point on the dial, that is, in the exact hourly position. It will be noted, however, that with a suitable arrangement this synchronizing may be effected when the deviation of the hands from the synchronous position is much greater than is possible with the device described hereinbefore. It should be obvious that the beveled portions of the plate 63 may be made so that they predominate over the horizontal edges 12. However, the range within which the hands may be synchronized by means of the latter' arrangement will be materially reduced.

Another modification of the invention will be In this form of the invention the instrumentalities for effecting the synchronizing are reversed with respect to the minute hand gear 24 and the reciprocable plate. The minute hand gear is provided with a notched member or disc 14 which is secured to the gear by means of a plurality of pins or rivets ,15 or by any other conventional means of attachment. The disc 14 is provided with two diametrically opposed V-shaped notches or slots. A plate It which is supported and guided by one of the spacing sleeves l8 and one of the gears 26 is disposed between the disc 14 and the hour hand gear 29. A pin or projection 11 is carried by the plate 18 in a position which is normally free of the disc 14 and protrudes rearwardly from the plate. The lower or working portion of the pin is provided with a V-shaped configuration. Preferably the angle subtended by the two lower surfaces of the pin 11 is equal to or slightly greater than the angle of the vshaped notches of the disc 14.

When it is desired to synchronize the hands of the clock, the plate 16 is given a downward movement whereby the pin TI effects engagement with one side of one of the V-shaped notches of the disc 14. Further downward movement of the plate produces a rotative movement of the disc 14 and also the gear 24 and minute hand I2. When the plate 16 has been moved to the bottom of its stroke, the pin 11 is disposed at the bottom of the V-shaped notch. By providing the pin 11 with an angularity greater than that of the notch in the disc, a firm seating of the pin in the notch is secured. Also, such an arrangement permits an accurate determination of the synchronous position of the hands. By means of the two oppositely disposed notches in the disc 14 it will be seen that the hands of the clock may be synchronized either exactly on the hour or exactly on the half hour.

In this modification of the invention, the movement of the plate 16 is effected by drawing it downward by means of a depending rod 18. The value of such an arrangement is that where the clock is located in a relatively inaccessible po-- sition such as in a display window or in an elevated position on the wall, the rod 18 may have attached to its lower extremity a cord or cable I9. The cord may be passed around a plurality of pulleys such as 8| and 82 whereby its free end may be easily reached whenever it is desired to reset the clock. Obviously such a resetting may be effected by merely pulling on the free end of the cord which effects the downward movement of the plate 16.

The modifications of the invention shown in Figs. 7 and 9 may also have incorporated in them a means for setting an alarm or signal device where such is provided. The means for attaining this end is shown and described in connection with Fig. 4 and its adaptation to these modifications should be obvious. The nature of the instant invention may be ascertained from the foregoing description and the scope thereof determined from the appended claims.

What is claimed is:

1. In a clock, a train of reduction gears, a supporting structure therefor, a minute hand gear, and means for rotating said gear to a predetermined position, said means comprising two pins positioned diametrically on and projecting from one face of said gear and a reciprocable member constrained to a longitudinal movement by one of said reduction gears and by said sup- ;i -porting structure and having a lateral portion to engage said pins.

2. In a clock, a plurality of gears including one associated with the minute hand of said clock, a plurality of pins diametrically positioned on and projecting from a face of said one gear, a reciprocable plate having a rectangular slotted guideway adapted to slidably engage the periphery of another of said gears, means having an edge thereof extending laterally of said plate in proximity to said pins, and manual means for moving said plate longitudinally relative to said other gear to rotate said one gear to a predetermined position by effecting engagement between said laterally extending edge and said pins.

3. In a clock, a train of reduction gears, a pair of spaced plates to journal said gears, a plurality of sleeves for suitably spacing said plates, a minute hand gear provided with diametrically positioned projections on one face thereof, a fiat member disposed adjacent said face and having an opening for said projections and a guide recess formed therein, and manual means for moving said member to effect engagement of an edge of said opening with one of said pins to produce rotation of said gear, said rotation ultimately bringing the other of said pins into contact with said edge, said flat member being guided in a straight line movement by one of said sleeves coacting with said recess and one of said reduction gears coacting with edges of said opening.

4. In a clock, a plate having an opening and provided with a guideway formed in one side of said plate, a train of reduction gears, a supporting structure for said gear train, one of said gears and part of said structure serving in cooperation with said guideway to restrict the movement of said plate to a longitudinal one, a minute from the center of rotation of said minute hand gear, and means including a manually operable device for effecting a reciprocating movement of said plate, said reciprocating movement effecting rotation of said minute hand gear by the engagement of an edge of said opening with said projections.

5. A clock comprising hands, a driving means therefor, a train of reduction gears, a pair of spaced plates for journaling said gears, a plurality of sleeves for suitably spacing said plates, one gear of said train being provided with two diametrically positioned pins extending from one face thereof, a device for rotating said one gear with respect to a second gear, said device comprising a flat member having a slot through which a third one of said reduction gears projects and serves as a guide for said member, said flat member being further characterized by a recessed portion having one edge thereof in sliding registry with one of said sleeves and an opening through which said pins project, a spring for urging said fiat member in a manner to effect engagement between a second edge of said recessed portion and said one sleeve, and means accessible from the exterior of the clock for moving the fiat member against the action of said spring to effeet the engagement of an edge of said opening with said pins.

EUGENE A. DEMONET.

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