Clockwork Mechanism For Large Clocks

Abstract

A clockwork mechanism for clocks with chimes comprising a clock movement, a striking mechanism, a control device for the striking mechanism, a driving motor for driving the striking mechanism and a set of batteries for the driving motor all constituted as seperate units mounted in the housing of the clock. At least the motor and batteries are detachably mounted for each replacement.

Description

BACKGROUND

a. Field of the Invention

The invention relates to a clockwork mechanism for large clocks provided with Westminister or similar chimes comprising a clock movement, a striking mechanism, a control device for the striking mechanism, a driving motor for driving the striking mechanism and a set of batteries for energizing the driving motor.

B. Prior Art

The assembling and dismantling operations of such a clockwork mechanism are comparatively complicated, as three different, mutually cooperating, sets of gear wheels are arranged in the clockwork housing. During repair operations, for instance, changing springs, the driving motor, or individual defective parts of the clock movement or the striking mechanism or the like, the above sets of gear wheels completely disassemble. Moreover, it is usually impossible to use clock movements or driving motors of different types in a particular construction of the clockwork in order to meet the requirements of various users.

SUMMARY OF THE INVENTION

According to the invention, the clock movement, the striking mechanism, the control device, the driving motor and the set of batteries are constructed as separate construction units which are arranged in a housing.

Various advantages result from this separated construction of the structural units, particularly the control and actuation of the striking mechanism, which cannot be achieved in the conventional arrangements without encountering difficulties. Thus, for instance, according to one embodiment of the invention, a switch, such as a pull and tumbler switch for deactivating the striking mechanism, can be arranged in the electric circuit of the driving motor. COnsequently, this switch may be easily actuated, and the clockwork mechanism can be installed in a table clock, a wall clock or a free standing clock, so that the striking mechanism can be switched on or off according to the desire of the user.

In a further advantageous embodiment of the invention, the control device for the striking mechanism and the mechanism for moving the hands of the clock are arranged on the front side of the a mounting plate, and the remaining units of the clockwork are mounted on the rear side of the plate. This results in a more practical utilization of space, and the entire clockwork mechanism can be constructed so as to be relatively flat.

In a further advantageous embodiment of the invention, there is provided a particularly simple construction of the control device for the striking mechanism. This control device comprises a conventional star-like control cam, which is driven by the clock movement and is provided with three identical curved teeth and with one higher curved tooth, wherein a contact switch inserted in the electric circuit of the driving motor can be closed every quarter of an hour by said control cam and by means of a lever mechanism, and wherein said contact switch is opened after the completion of the quarter stroke as a result of rotation of a quarter-hour disc which is rigidly connected to the shaft of the striking mechanism. The lever mechanism according to the invention can consist of a few simple levers, which are in contact on the one hand with the star-like control cam and on the other hand with the quarter-hour disc. The quarter-hour disc is provided in proximity of its circumference with pins, which actuate the lever mechanism after the quarter-hourly stroke has been completed in such a manner that the contact switch opens.

The hands of the hand moving mechanism can be rotated in both the clockwise and the counter-clockwise direction in order to set the clock to the correct time. During this rotation, the star-like control cam also rotates, and, as a result, the striking mechanism departs from the proper sequence. In order to automatically return the striking mechanism in the proper sequence, the quarter-hour disc is provided, according to still another embodiment of the invention, with a recess on its circumferential surface, in which a part attached to the lever mechanism drops at approximately the time shortly after the striking of the third quarter of an hour, and, consequently, the contact switch can be closed only after actuation of the lever mechanism by the higher curved tooth of the star-like control cam. Consequently, the striking mechanism returns to the proper sequence at the time of striking the next full hour at the latest.

In a clockwork mechanism for large clocks according to the invention, it is possible to synchronize the striking mechanism with the movement of the hour wheel of the handle moving mechanism in a particularly simple manner. The cam discs for actuating the quarter-hour hammers and the hour hammer are seated on the shaft of the striking mechanism. According to the invention, the hour wheel of the hands moving mechanism is connected by means of interposed gear wheels with a gear wheel which is loosely supported on the shaft of the striking mechanism and is provided with pins, one of which after a full hour has been passed actuates a cam segment for starting the hour strike. The cam segment is pivotably supported on the hour cam disc and is held in its starting position by means of a spring in such a manner that it disengages from contact with the hour hammer of the striking mechanism. Consequently, the pins, which are located on the gear wheel which is driven from the hour wheel by means of the interposed gear wheels, determine the number of strikes which the hour hammer makes at each occasion. After the number of strikes corresponding to the given hour has been achieved, one of these pins engages the pivotably supported cam segment in such a manner that the teeth of the cam segment can no longer actuate the hour hammer.

The transmission of the driving force from the hour wheel of the handle moving mechanism to the gear wheel which is loosely supported on the shaft of the striking mechanism is achieved in a preferred embodiment with three interposed wheels arranged therebetween, the transmission ratio between the hour wheel and the above gear wheel being 1:3 in total. Therefore, the gear wheel conducts a one-third rotation in the course of twelve hours. In this case, three pins are provided which are equally spaced along the circumference and which serve the purpose of actuating the cam segment.

In a preferred embodiment, the hour cam disc of the striking mechanism is provided with only one rigid cam tooth for the full hour and the cam segment which is pviotably supported on this cam disc is provided with eleven additional cam teeth for actuation of the hour hammer. This cam segment can be shifted between two swivel positions, wherein the eleven cam teeth can come into contact with the hour hammer in only one of these positions. The cam segment can be held in this position by means of a crank which is under influence of a spring, wherein this tilted position can be secured by an ascending curved cam attached to the cam segment and abutting against a rigid stop, and the crank holding said curved segment in the above tilted position can be released by a pin of the gear wheel which is loosely supported on the shaft of the striking mechanism. As soon as the crank is released, the further teeth of the curved segment can no longer actuate the hour hammer and the striking of the hour ceases after the correct number of strokes has been achieved.

In a preferred embodiment, the crank is provided with a nose, which is preferably directed inwardly and which in a position in which the crank presses the cam segment outwardly, is located in the path of the pins of the gear wheel which is loosely supported on the shaft of the striking mechanism. As a result of this, the crank is released at the proper moment corresponding to the position of the associated pin and the cam segment drops under the influence of a spring to the position in which it is out of engagement with the hour hammer. After the associated pin of the gear wheel has completed its travel up to a point behind the nose, the following pin of the gear wheel comes into engagement with the nose attached to the crank always after the end of the hour striking for the next twelve hours.

It is often desirable in such clocks provided with striking mechanism or chimes to provide an opportunity to deactivate the striking mechanism during a certain time period, for instance, for the duration of night. It is true that this can be generally achieved by the switch in the electric circuit of the driving motor; however, according to a further advantageous embodiment of the invention, the deactivation of the striking mechanism for a certain period of time can be accomplished automatically. For this purpose, a control curved cam is provided on one of the interposed gear wheels, which deactuates the driving motor for the duration of a time period corresponding to a predetermined difference of angular positions of this interposed gear wheel. For example, the curved control cam can actuate the lever mechanism in such a manner that the same cannot activate the striking mechanism. This embodiment of the invention is particularly simple to construct and to operate, as it can be arranged at any arbitrarily chosen location on the axle of the interposed gear wheel, depending on the construction of the clock. The same effect could also be achieved if, for instance, a contact switch inserted in the electric circuit of the driving motor were opened by this curved cam for a limited period of time.

An arbitrary selection of the time of deactivation can be achieved by making the control curved cam displaceable in the direction of rotation on the interposed gear wheel or on its axle. An adjustment of the duration of the period of deactivation can be achieved by utilizing two curved control cams which are attached to the gear wheel and are displaceable in relation to each other and to the gear wheel in the direction of rotation. The first curved control cam determines the beginning and the other the end of the period of deactivation.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic view of the clockwork mechanism from the rear of a mounting plate supporting the clockwork mechanism;

FIG. 2 is a schematic view from the front of the single mounting plate;

FIG. 3 is a schematic view, slightly simplified, of the striking mechanism;

FIG. 4 is a cross-section taken approximately along line IV--IV in FIG. 3;

FIG. 5 is a cross-sectional view taken approximately along the line V--V in FIG. 3, showing the striking mechanism shortly before the beginning of the full hour stroke; and

FIG. 6 is a cross-sectional view corresponding to that of FIG. 5, but in a position shortly before the first quarter-hour stroke.

DETAILED DESCRIPTION

The structure of the clockwork mechanism for large clocks according to the invention can be clearly seen from FIG. 1, showing the various single structural units, which are attached to a single mounting plate located behind the plane of the drawing. The various single structural units are simplified in FIG. 1, and they are shown as separate blocks. The entire clockwork mechanism is composed of a clock movement 10, a striking mechanism 12 with hammers 14, a driving motor 16 for the striking mechanism and a set of batteries 18 for energizing the driving motor 16 and the clock movement. The movement 10 can be of arbitrary shape ad construction, such as clock movements which are commonly marketed at the present, e.g., balance wheel clocks or even pendulum clocks. The striking mechanism is mounted in such a position that its hammers 14 are able not only to strike horizontally arranged gong rods, but also vertically arranged gong rods in which case the hammer support arms are bent upwardly 90.degree. to the position 20 as shown in chain-dotted lines in FIG. 1. By this arrangement, it is possible to install the same clockwork in table clocks, wall clocks or standing clocks. For the same reason, a switch 22 which serves the purpose of deactivation of the striking mechanism and which is inserted in the electric circuit of the driving motor 16 in a manner which is not shown in detail, is provided as a tumbler and pull switch. The set of batteries which can energize both the drive of the clock movement and the driving motor of the striking mechanism, preferably is not rigidly connected to the body of the clockwork, but is located at an easily accessible place in the housing, for instance, at the inner surface of the door of the housing. The batteries are connected to the clockwork mechanism by means of flexible wires provided with disconnectible plugs.

The front side of the mounting plate 24 is schematically shown in FIG. 2, whereas the rear side of the plate with the structural units attached to the same is shown in FIG. 1. The set of batteries 18 can be either rigidly connected to this mounting plate or attached at any other, easily accessible location in the housing of the clock, as already mentioned above.

On the front side of the plate 24, there is provided a mechanism for moving the hands of the clock, and a control device for the striking mechanism. The clock movement of hand moving mechanism. is provided in a conventional manner with an hour wheel 26, which meshes with a first interposed gear wheel 28, which in turn is operatively connected to with a second interposed gear wheel 30, which meshes a third interposed gear wheel 32 (shown in FIG. 4) in a manner which is not shown in greater detail. The third interposed wheel 32 meshes with a gear wheel 36 which is loosely supported on a shaft 34 of the striking mechanism, the transmission ratios being chosen in such a manner that the gear wheel 36 has a 1:3 ratio in respect to the hour wheel 26. Hence, the gear wheel 36 rotates one third of a revolution in the course of one full rotation of the hour wheel.

Furthermore, the clock movement is provided with two hands 38 and 40 which are shown in chain-dotted lines in FIG. 2. A second ring gear 42 of the hour wheel meshes in a conventional manner with an interposed wheel 46 by means of a drive 44, wherein the interposed wheel 46 drives a star-like curved cam 48 provided with three curved teeth 50 of identical height and a curved tooth 52 with a larger height. The transmission ratios are chosen in such a manner that the star-like curved cam is subject to one rotation per hour.

A roller 54 is mounted on a lever 58 which is rotatably supported on an axle 56, the roller 54 following the cam teeth 50 and 52, and, as a result of this movement, the lever 58 acts on a flange 60 abutting the lever 58, the flange being integral with a lever 62 which is tiltable about the same axle 56 as lever 58. Hence, both levers 58 and 62 are pivoted in the counter-clockwise direction. During this pivoting movement, an additional lever 66 attached to the lever 62 by joint 64 is pivoted in a direction which extends downwardly and to the right against the opposition of a return spring 68. The lever 58 and the flange 60 of the lever 62 are urged into abutment by means of a spring 70.

A quarter-hour disc 74 is attached to the striking mechanism shaft 34 below the lever 66 and the disc 74 is provided with four quarter-hour pins 76 which have successively increasing spacing.

If the lever 66 moves to the right and downwardly as a result of the roller 54 coming into contact with a curved tooth 50 of the star-like curved cam 48, a nose 72 at the end of the lever 66 is moved around the first quarter-hour pin 76 and drops into the space immediately therebehind. Simultaneously, a projection 78 provided in the center of the lever 66 drops behind a central pin 80 on an additional lever 84 which is rotatably supported on an axle 82. By these operations, the leverage is in a position in which it is prepared for the actuation of the striking mechanism. Now, if the roller 54 drops from one of the cam teeth, in the illustration of FIG. 2 from the cam tooth 50 for the first quarter of an hour, the lever 66 is retracted upwardly and to the left by means of spring 68, and it pulls, by its central projection, 78, the lever 84 in the same direction whereby the lever 84 closes a contact switch 88 by means of an upper pin 86. The switch closure connects the driving motor 16 to the voltage source. However, the driving motor is energized only if the switch 22, which is inserted in its electric circuit, is closed.

As soon as the driving motor is energized, the quarter-hour disc 74 which is connected thereto starts to move in the counter-clockwise direction. The second quarter-hour pin 76 presses against the nose 72 of the lever 66 toward the end of the first quarter-hour period, and lifts the lever 66. The central pin 80 of the lever 84 disengages from the projection 78 and the lever 84 drops back and opens the contact switch 88. The driving motor stops. The same process is repeated for successive quarter-hour periods. The number of quarter-hour strokes changes as a result of the increasing mutual distance of the quarter-hour pins 76. Between the fourth and the first quarter-hour pin 76, four quarter-hour strokes, as well as maximally twelve hour strokes are effected, i.e., the quarter-hour disc 74 rotates by more than one half of its entire rotation during the stroke of any full hour so as to reach the first quarter-hour pin. The number of the hour strokes to be sounded at each occasion is determined by the striking mechanism itself in a manner which will be explained hereafter in greater detail.

The setting and adjustment of the exact time can be effected in the counter-clockwise, as well as in the clockwise direction. If the hands are rotated in the counter-clockwise direction, the star-like control cam also rotates in the same direction. As a result of this, only the lever 58 is lifted, and drops again on the flange 60 of the lever 62 under the influence of the spring 70. Consequently, the additional levers 66 and 84 of the lever mechanism are not actuated. If the hands are rotated either in the counter-clockwise as well as in the clockwise direction, the striking mechanism will be brought out of the proper sequence in respect to the time shown by the hands of the clock, since the position of the star-like control cam 48 in relation to the quarter-hour disc 74 has been changed by moving the hands, and, moreover, the driving motor 16 is first actuated for a short period of time by the lever 84 during the clockwise rotation of the hands, and is stopped only by the next following quarter-hour pin 76. In order to return the striking mechanism to the proper sequence, the quarter-hour disc 74 is provided on its circumference with a recess 90. The lever 84 rests by means of an inner pin 92 against the circumferential surface of the quarter-hour disc 75, and in the course of every hour, after finishing the three-quarter-hour stroke, it drops into recess 90. As a consequence, the central pin 80 of the lever 84 moves such a distance from the projection 78 of the lever 66 that only the high curved tooth 52 of the star-like control cam 48 can move the lever 66 by means of the levers 58 and 62 so far that it can drop behind the central pin 80 of the lever 84 by its tooth 78. Since the high tooth 52 of the control cam corresponds to a full hour of the position of the hands, the lever 84 is caught in this position and the following sequence of strokes is started after the drop of the lever 58 from the high curved tooth 52, which, at the particular moment, is the full-hour stroke. This menas, that the synchronization between the position of the hands and the striking mechanism is always renewed at the next full hour.

A fine adjustment of the lever mechanism can be achieved by means of an eccentric stop 94 for the lever 62, which stop is rotatably supported by the single mounting plate 24.

The driving motor 16 is detachably connected to the striking mechanism 12 in a manner which is not shown so that use can be made of various available units not only for economic reasons, but also for reason of repair, as the motor is probably the apparatus most likely to be subject to breakdown. The clock movement 10 is also replaceable in a similar manner and for similar purposes.

The control device according to the invention, to be used for the striking mechanism, makes possible a particularly simple additional device for deactivating the striking mechanism, for example, for the duration of the night hours. The interposed wheel 30 rotates once in the course of 24 hours, and a sector member 98 provided with a curved surface 96 is attached to wheel 30 so as to be rotatable about an axle 100. A screw 102 is attached to the interposed gear wheel 30 and extends in a circular slot 104 of the sector member 98. By tightening the screw 102, the sector member 98 can be fastened in any arbitrary position to the wheel 30. The length of the curved surface 96 corresponds to the duration of deactivation of the striking mechanism. For instance, the sector member 98 can be divided into two parts, which can be displaced in relation to each other, so that even the duration of deactivation of the striking mechanism can be predetermined. For example, the curved surface 96 can lift the lever 66 sufficiently high, by means of a roller 106 attached to the lever 66, so that the lever 66 can no longer actuate the lever 84 by projection 78. Consequently, the striking mechanism is put out of operation. Instead of the actuation of the lever 66 by means of the roller 106, the curved surface 96 could also, for instance, directly open a contact switch inserted in the electric circuit of the driving motor 16 for a certain period of time. The deactivation of the striking mechanism could be arbitrarily made or anulled by means of a further switch (not shown) and which could be arranged in parallel to the contact switch. This control device can also be provided on a different location at the axle 100, so that it is accessible from the rear.

The construction and control of the striking mechanism are shown in FIGS. 3 to 6. The quarter-hour discs 108 and the hour cam disc 110 are seated on the striking mechanism shaft 34. The quarter-hour hammers 112 and the hour hammer 120 are actuated by these cam discs. Another cam (not shown) can be connected to the hour hammer 120, which lifts the single quarter-hour hammers simultaneously with the hour hammer, so that a chord is produced in the course of each full hour stroke. The arrangement of the hour cam disc 110 on the common axle of the striking mechanism with the quarter-hour cam discs 108 differs from conventional striking mechanisms. In the conventional mechanisms, the hour striking mechanism has its own main spring or its own chain as a driving means and the power source and is released by the high tooth of the star-like switching cam in cooperation with the quarter-hour striking mechanism. In order to synchronize the hour stroke, contrary to the known embodiments, only the three interposed wheels 28, 30 and 32 are needed in the clockwork mechanism according to the invention, said wheels representing the connection between the hour wheel 26 of the hand moving mechanism and the gear wheel 36 loosely supported on the shaft 34 of the striking mechanism. As already explained, the gear wheel 36 rotates by one-third of its total rotation in the course of twelve hours. Three pins 116 are equispatially located along the circumference of the gear wheel 36 and these pins change their positions in exactly 12 hours. These pins 116 produce the following effect.

The hour cam disc 110 is provided, as shown in FIGS. 5 and 6, with a rigid tooth 118 for the full hour. In a manner shown in FIG. 5, the tooth 118 actuates a tooth 122 rigidly connected to the hour hammer 120, and, as a result of this engagement, 1 hour stroke is accomplished. The teeth 124 for the hour strokes of two to 12 are located on a cam segment 126, which is therefore, provided with a total of eleven teeth 124 which are mutually equally spaced. The cam segment 126 is pivotable about an axle 128 and is supported on the hour cam disc 110, and provided with an ascending curved cam surface 130 at its end opposite the teeth 124. During the movement of the ascending curved cam surface 130 along a rigid, rectangular stop 132, the cam segment 126 is tilted from the position shown in FIG. 6 into the position shown in FIG. 5, while a crank 134 engages a pin 136 of the cam segment 126 and consequently, holds the segment in this position. The crank 134 is also rotatably supported on the hour cam disc 110 by means of axle 138, and is pressed against the pin 136 by means of a spring 140. The teeth 124 of the cam segment 126 actuate the hour hammer 120 in this position. As soon as the pin 116, of the gear wheel 36 which is momentarily in the region of the crank 134, engages an inwardly projecting nose 142 of the crank, the crank is disengaged from the pin 136 against the force of the spring 140, and, as a result, the cam segment 126, which has been freed from the stop 132 in the meantime, can be retracted to the position shown in FIG. 6 by means of a return spring 144. In this position, the pin 136 comes to rest on a second recess 146 of the crank.

The ascending curved cam 130 travels along the stop 132 in the course of the duration of the fourth-quarter stroke and lifts the cam teeth 124 to the operative position, i.e., to the elevation of the rigid tooth 118. Herein, the position of the first pin 116 engaging the nose 142 of the crank 134 determines the amount of hour strokes which can be effected in each specific hour stroke. The gear wheel 36 rotates, as can be seen from the above explanation, by exactly a 10.degree. angle which is the distance between the teeth 124, so that one more tooth 124 is allowed to actuate the hour hammer 120 every hour, before the cam segment 126 drops back. This continues until the 12th hour is reached. For 1 o'clock, the following pin 116 comes into action in such a manner that the cam segment 126 forcedly projected by means of the ascending curved cam 130 is allowed to fall back immediately, before its first tooth 124 can engage the hour hammer 120.

As can be seen from FIG. 3, the driving motor 16, which is also attached to the base plate 24, drives the striking mechanism shaft 34 by means of a gear 148, on which shaft the quarter-hour disc 74 is also attached. The representation of the control device, which is located on the left side of the base plate 24 in FIG. 3, is significantly simplified and is not to scale.

Claims

What is claimed is:

1. A striking mechanism for a clock comprising a time gear train for moving the hands of the clock including an hour wheel, a striking control mechanism responsive to said time gear train for actuating said striking mechanism, said striking mechanism comprising hammers for sounding at the quarter hour and hour, respectively, cam discs for actuation of said hammers including an hour cam disc with a single tooth on the periphery thereof for actuating the first stroke of the hour sounding hammer, a shaft mounting said cam disc, a motor for driving said shaft, said motor being intermittently actuated by said striking control mechanism, a gear wheel loosely mounted on said shaft, a gear train driven by said hour wheel for driving said gear wheel at a transmission ratio of 1 to 3 relative to said hour wheel, said gear wheel having three pins mounted thereon in equally spaced angular relation, a cam segment pivotally mounted on said hour cam disc and having a peripheral surface with eleven hammer actuating teeth thereon, means biasing said cam segment to a first position out of cooperation with said hour hammer, means to pivot said cam segment to a second positon enabling cooperation of said teeth with said hour hammer, and means for holding said cam segment in said second position, said holding means coating with one of said pins so that on each occasion when the sequence of strokes has been completed, the cam segment is released permitting said biasing means to return said cam segment back to said first position.

2. A mechanism according to claim 1 comprising a clock movement and a set of batteries for the driving motor, and driving motor and the set of batteries being constituted as separate units and means supporting the units on a common mounting structure.

3. A mechanism according to claim 2 comprising an electric circuit for the driving motor including a switch means for activating the striking mechanism.

4. A mechanism according to claim 3 wherein the clock movement includes hour and minute hands, and a mechanism for moving the hands, the control mechanism for the striking mechanism and the mechanism for moving the hands being arranged on one side of the mounting structure and the remaining units on an opposite side thereof.

5. A mechanism according to claim 2 wherein at least the set of batteries and the driving motor are detachably installed on the mounting structure.

6. A mechanism according to claim 2 wherein the control mechanism for the striking mechanism comprises a star-like control cam driven by the clock movement and including three identical curved teeth and one higher curved tooth, a contact switch inserted in the electric circuit of the driving motor and a lever mechanism between the control cam and contact switch to close the switch every quarter of an hour, said striking mechanism including a shaft, a quarter-hour disc rigidly connected, to open the switch after the completion of the quarter-hour stroke, to said shaft of the striking mechanism and coupled to the lever mechanism.

7. A mechanism according to claim 6 wherein the quarter-hour disc is provided with a recess on the circumferential surface thereof, the lever mechanism including a pin which drops into the recess at a time approximately after the stroke of the third quarter of an hour, such that the contact switch can only be closed after actuation of the lever mechanism by the higher curved tooth of the star-like control cam.

8. A striking mechanism as in claim 1 wherein said holding means is a crank pivotally mounted on said hour cam disc and said crank has a nose located in the path of said pins to coact therewith for releasing said cam segment.

9. A mechanism according to claim 8 comprising a control curved cam on one of said interposed wheels for deactivating the driving motor for a time period corresponding to the difference of angular positions of this interposed wheel.

10. A mechanism according to claim 9 wherein the control curved cam engaged the lever mechanism such that the same cannot actuate the striking mechanism.

11. A mechanism according to claim 10 wherein the control curved cam is attached to one of the interposed wheels so as to be capable of being adjustably displaced in the direction of rotation.

12. A mechanism according to claim 11 wherein two curved control cams are provided on said one of the interposed gear wheels as as to be displaceable in the direction of rotation in relation to each other as well as in relation to the interposed gear wheel.