Patent Application
20180284697
The present application claims priority to Swiss Patent Application No. 00425/17, filed Mar. 30, 2017, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present invention relates to the field of mechanical timepieces, in particular wristwatches, which are equipped with a digital time display by means of multiple numeric disks.
In particular, the present invention relates to a timepiece in the form of a wristwatch with a digital display, the wristwatch comprising a minute-units disk, a minute-tens disk, and an hour ring, and with a movement having a balance-spring system and a gear train by means of which a minute-units wheel of the minute-units disk is advanced rotatably with ten steps per revolution in cyclic steps, and with a switching device by by means of which the minute-tens disk is advanced rotatably with six steps per revolution, wherein the hour ring is advanced rotatably during one revolution of the minute-tens disk by the minute-tens disk via a Maltese intermediate wheel with twelve steps per revolution, as well as with a manually actuatable disk setting means, wherein the movement comprises at least a first barrel, a first transmission chain and a second transmission chain, wherein both transmission chains are connected to a release mechanism and the first transmission chain controls the second transmission chain by means of the release mechanism such that the second transmission chain transmits every minute, clocked via the balance-spring system of the movement, a force in the form of a rotational movement to the minute-units wheel.
Time pieces without hands, which indicated the time with moving or jumping numbers on rotating disks or rings, appeared as early as the 16th century. However, these were monumental clocks on towers or churches.
In the second half of the 19th century, jump hour pocket watches appeared, which digitally indicated both the hours and the minutes through mechanically jumping digits, wherein the seconds, however, were indicated in analog with a hand. In particular, the manufacturers IWC, Cortébert Watch, Gedeon Thommen, Aeby & Landry, Kaiser, and others produced such jump hour pocket watches. The expert can find an overview of this production at that time in the book “Die Sprungziffern-Taschenuhren” by Alex Kuhn, publishing company Simonin, 2010. The first technical descriptions of this type of watch can be found in particular in the so-called Pallweber patents, see, for example, the German Reich Patent 25 042 from 1883.
In the meantime, these pocket watches have been essentially completely ousted from the market by mechanical wristwatches with analog displays. In the sixties, cheaper electronic wristwatches with digital displays of any kind also appeared, which, at first glance, made a further development of mechanical watches with digital display seem little meaningful. In view of the current demands of the consumer in terms of accuracy of indication and adjustability, the field of mechanical watches having a digital time display can thus again be regarded as technical new ground.
A few innovations with respect to the pocket watch production of the 19th century shall be mentioned in the following:
The patent specification DE 10 2007 042 797 discloses a watch, in particular a wristwatch, having a main energy storage, by which, via a gear train, a tensioning element of a tensioning device forming a first device configured to be switched in a stepwise manner can be rotatably driven, controlled by a tensioning control, in cyclic steps about a tensioning axis and a storage hairspring connected with one end to the tensioning element is tensioned, wherein the other end of the storage harspring is connected to a wheel rotatably driving the movement, which is engaged with the train of the escapement, wherein a further device configured to be switched in a stepwise manner can be rotatably driven in cyclic steps by an element of the gear train from the main energy storage to the tensioning element. The movement of this watch is mainly used in so-called movements with constant torque and therefore has a tensioning device charging the storage hairspring at regular time intervals to avoid large torque fluctuations.
The patent specification DE 10 2009 019 335 discloses a watch, in particular a wristwatch, having a drive, through which a gear train of a digital display having a plurality of numeric disks can be rotatably driven in cyclic steps, wherein a drive wheel allows to rotatably advance a units wheel of a minute-units disk with ten steps per revolution, with a switching device which is driven by the units wheel and which allows to rotatably advance a minute-tens disk with six steps per revolution, and with an numeric hour disk which can be advanced rotatably by the minute-tens disk with twelve steps per revolution during a revolution of the minute-tens disk, wherein a pinion which engages in the gear train can be driven by a manually actuatable disk adjusting wheel, wherein the pinion is positively coupled via a locking mechanism with the drive wheel. The coupling realized by said locking mechanism between the pinion manually drivable by the disk adjusting wheel and the drive wheel of the train of this watch has a specific configuration and, in particular, is mounted axially sliding on the axis of the pinion arranged coaxially with the drive wheel, wherein the train is designed as a continuous gear train with successively driven numeric disks in order to save installation space and to reduce the number of components.
Swiss patent specification CH 511 471 also discloses such a watch, wherein a minute-units disk may be advanced rotatably with ten steps per revolution, with a switching device by which a minute-tens disk may be advanced rotatably with six steps per revolution and with an numeric hour disk which may be advanced rotatably by the minute-tens disk with twelve steps per revolution during a revolution of the minute-tens disk. The movement has a first transmission chain which transfers the force from a first barrel to a first escapement of a regulator of the watch, and a second transmission chain which transmits the force from a second barrel to the indicator disks, wherein the rotation of the wheels of the second transmission chain is controlled by a wheel of the first transmission chain. The necessary blocking of the second transmission chain between the stepwise advancing of the indicator disks as well as their release at the time of a step of advance is accomplished via second pallets of a second escapement in cooperation with superimposed, mutually rotatable plates, which requires a relatively complex structure of the movement.
An instantaneous display mechanism of a watch of this type is disclosed in the Swiss patent specification CH 581 857, wherein a drive wheel of a indicator disk meshes with an intermediate wheel, which is mounted on a rocker. A block of the rocker is engaged with a toothing of the disk, however, the block is released from the toothing both during a manual correction operation as well as by the automatic dislocation of the rocker during the normal course of the watch.
The European Patent Application EP 3 032 348 also discloses an instantaneous display mechanism which comprises a drive wheel, a time display and a jumping member that is mounted on said time display and coaxial with the drive wheel, as well as a cam configured to release four-arm pallets once per unit of time. This arrangement is especially designed for displays that realize a jumping switching every second, in particular using a single source of energy in the watch movement.
Despite the previously known embodiments, it is further desirable to provide a watch of the above mentioned type which shows an as small a change as possible of the amplitude of the balance-spring system, respectively of the frequency of the regulator of the movement, during the stepwise rotation of the indicator disks that are relatively heavy as compared to hands,
The aim of the present invention is therefore to avoid the disadvantages of the previous embodiments, the realization of the above-mentioned advantages, and to provide a watch which disposes of a digital display having several numeric disks, wherein the numeric disks should be released instantaneously and be advanceable with the least possible expenditure of energy. In particular, the indicator disks should stand for one minute, while at the end of each minute, as soon as the second hand has reached sixty seconds, the minute-units disk should be immediately released and further rotated by one position. At the end of ten minutes, the minute-tens disk should additionally be further rotated and, at the end of one hour, the hour disk further rotated by one more position. A further object of the present invention is the provision of a manually actuatable disk setting means for safe setting of the time in both directions. A further object of the present invention is an attractive digital time display in the context of mechanical wristwatches. This is to be achieved by using a movement that is designed constructionally as simple and robust as possible and that ensures safe operation.
According to a first aspect of the invention, a timepiece according to the invention comprises, in particular, a release mechanism with a control disk, two release levers each having a first lever arm and a second lever arm, and a release wheel, wherein the first lever arms of the two release levers are positioned in shifted manner and bear with pressure on the circumference of the control disk such that, after the end of every minute, the first lever arm of one of the release levers falls from the control disk edge into a recess of the control disk and the second lever arm of this release lever releases the release wheel of the release mechanism, such that the second transmission chain rotates freely until a tooth of the release wheel strikes against the second lever arm of the other release lever, thus allowing the minute-units wheel and the minute-units disk to rotate by one step, and the first transmission chain comprises a centre wheel driven by the first barrel, a third wheel driven by the centre wheel, and an intermediate pinion meshing with the third wheel, wherein said control disk is fastened to the axis of the intermediate pinion.
These features achieve a number of advantages, in particular, the amplitude fluctuations in the balance-spring system are kept low and it is possible to implement sixty releases per hour with a comparatively simple assembly, in particular thanks to a control disk designed as a cam disk divided into two sections and two associated levers, which has the advantage that the steps or sections can be made larger, which in turn causes a safer functional sequence.
According to a second aspect of the invention, a timepiece according to the invention comprises a manually actuatable disk setting means which has a plurality of setting wheels respectively serially meshing with each another, which are movable by a winding stem in its pulled-out position by means of a coupling pinion, wherein the last setting wheel is fixedly attached to the minute-units disk and the assembly consisting of the last setting wheel and the minute-units disk is arranged loosely and freely rotatable on an intermediate wheel pinion, which is a part of the second transmission chain, and wherein a star is coaxially fastened to the intermediate wheel pinion and a conjugately shaped detent spring is mounted on the minute-units disk to allow the alignment of the minute-units disk in a dial window of the timepiece as well as, in the presence of a higher force than the detent spring force, to allow a stepwise coupling and decoupling between the intermediate wheel pinion and the minute-units disk.
These features allow to realize a disk setting means with a safe setting of the time in both directions, wherein the disk setting means has a simple and effective coupling between the intermediate wheel pinion and the minute-units disk.
According to a third aspect of the invention, in a timepiece according to the invention, the axes of the minute-units and minute-tens disks are arranged parallel to each other and inside the hour ring, wherein the minute-units disk is configured with at least two stages and the edge of its upper stage bearing digits is opposite the edge of the minute-tens disk, such that the surfaces of the two disks lie in the same plane. Preferably, the minute-units disk, the minute-tens disk and the hour ring of the digital display are also connected to one another via a switching device in the form of a Maltese cross drive.
These features realize an aesthetically pleasing, digital time display for mechanical timepieces, wherein the display leads to a reasonable thickness of the movement with a comparatively small space requirement of the indicator disks. In addition, the arrangement of the axes of the minute-units and minute-tens disk parallel to each other and inside the hour ring allows a certain freedom in the arrangement of the time display on the dial of the timepiece.
Further features and advantages will become apparent from the dependent claims as well as from the description setting out in detail the invention in the following by means of the accompanying drawings.
The accompanying drawings illustrate by way of example two embodiments of a timepiece with a digital display according to the invention. It is shown in
Two embodiments of the invention are now described in detail below with reference to the drawings.
A digital display 10 with a drive and release system for the disk rotation according to the present invention is intended for integration into a wristwatch. As shown in
The three display disks 11, 12, 13 of the digital display 10 are connected to each other via a switching device, which is configured in this embodiment as a Maltese cross drive. The latter is structured as follows: The lowest stage of the minute-units disk 11 carries a roller 15 which engages in the Maltese train on the bottom side of the minute-tens disk 12 and which causes the latter to turn during the switching of the minute-units disk 11 from the numeral “9” to the numeral “0”, wherein a rotation of the minute-units disk 11 by 36° causes a rotation of the minute-tens disk 12 by 60°. If the indicator disks stand as shown in
A first embodiment of a movement of a timepiece housing this digital display 10 is now described below with reference to
In order to ensure a high releasing precision during the switching operations of the digital display 10 and simultaneously to minimize amplitude fluctuations in the balance-spring system 26 of the movement, in this embodiment, the release mechanism 40, as shown in
The total angular width of 12° of the sections of the step disk 41 can preferably be divided asymmetrically in order to further increase the functional reliability of the release mechanism 40. For example, the angular width of the step shown in
During the normal operation of the movement, the step disk 41 continuously rotates with the minute wheel 22, wherein the first lever arms of the two release levers 42, 43 slide over the surface of the outer circumference of the step disk 41. At the end of each minute, the first lever arm of one of the release levers 42, 43 falls from the step disk edge into a gap of the step disk 41 and releases the release wheel 44 by means of its second lever arm. As a result, the second transmission chain 30 of the switching gear train can rotate freely until the tooth of the release wheel 44 strikes against the second lever arm of the other release lever 42, 43. Thus, the minute-units disk 11, which is preferably directly mounted on or in kinematic connection with a minute-units wheel 36 of the second transmission chain 30 of the switching gear train, rotates one step further, which corresponds to a rotation of 36° and each time makes visible the next digit on the minute-units disk 11 in a window (not shown in the figures) in the dial of the watch.
A second embodiment of a movement of a timepiece housing the digital display 10, which has a further improved releasing accuracy, is now described below with reference to FIGS. to 8b. Similar to the movement of the previously described embodiment, the movement according to the second embodiment has, as shown in
In contrast to the release mechanism 40 according to the first embodiment of a movement according to the invention, in which the tapping of the moment in time of release is done using the minute wheel 22, respectively the step disk 41 fastened thereto, the tapping of the moment in time of release is carried out in the second embodiment of a movement according to the invention using the third wheel 53, due to the fact that the cam disk 71 is fastened to the intermediate pinion 54 meshing with the third wheel 53. The available torque is therefore slightly lower compared to the first embodiment of a movement according to the invention, but is sufficient and higher than the torque on the fourth wheel 56. On the other hand, by this way the rotational speed of the cam disk 71 of the second embodiment of a movement according to the invention, which is one revolution per hour at the step disk 41 of the first embodiment, can advantageously be significantly increased to one revolution per four minutes, since the modification of the transmission chain 50 by adding the intermediate pinion 54 and the loosely mounted third additional wheel 55 allows a modified and, depending on needs, within certain limits selectable number of teeth or gear transmission ratio at these wheels. The number of sections, each with a tooth and a recess, on the cam disk 71 is also accordingly selectable, wherein the cam disk 71 of the second embodiment of a movement according to the invention, as shown in
Like the first embodiment of a movement according to the invention, a movement according to the second embodiment of the present invention, on the other hand, has a switching gear train, which, as shown in
The release levers of the release mechanism 70 are also designed analogously to those of the first embodiment and are designed as pivotally arranged release levers 72, 73, each with a first and a second lever arm which preferably each correspond to a short and a long lever arm, with the difference that the axes of both levers are arranged coaxially. One of the release levers 72 is fixedly connected to an associated shaft serving as a pivot axis and the other release lever 73 is loosely and freely rotatably mounted on the pivot axis and axially secured with a bushing, as shown schematically in
In the following, the manually actuatable disk setting means, which allows the manual adjustment of the position of the numeric disks 11, 12, 13 of the digital display 10, is now described with reference to
The bearing stud of the intermediate wheel pinion 86 is, as shown in
As soon as the winding stem 77 is rotated in its pulled-out position, the minute-units wheel 11 is put into rotary motion by the above-mentioned wheel chain shown in
Preferably, the disk setting means further comprises a blocking device, a corresponding embodiment of the device now being described with reference to
After explaining the structure of the disk setting means, the winding of the barrels 21, 31, 51, 61 shall be explained in the following, for completeness of the description of the present invention, by means of illustrations 13, 14a and 14b. The two barrels 21, 31, respectively 51, 61 of the driving gear train and the switching gear train of the movement are wound up as follows. By rotating the winding stem 77 in its non-pulled position, the coupling pinion 80 is driven by a square of the winding stem 77, wherein the coupling pinion 80 transmits this rotational movement via its locking teeth onto the winding pinion 97. As a result, as shown schematically in
The barrels 21, 31, 51, 61 are preferably designed such that they run, even in the case of an identical length of the balance or tension springs in the first 21, 51 and the second barrel 31, 61, at different speeds and therefore do not have the same rotary speed, in particular such that the second barrel 31, 61 has a lower rotary speed than the first barrel 21, 51. This ensures that there is always enough force present on the second barrel 31, 61 to switch the display numeric disks 11, 12, 13 of the digital display 10 until the watch has reached its power reserve. In order to allow that the watch, respectively the barrels 21, 31, 51, 61, can always be fully wound up, it has two winding springs with a sliding clamp known to those skilled in the art. Optionally, the first barrel 21, 51 can also be provided with a balance or tension spring with a fixed stop for a manual winding.
Finally, it should be expressly pointed out at this point that the above-described two embodiments can be easily simplified by a specialist skilled in watchmaking so that instead of a first 21, 51 and a second barrel 31, 61, that are each used as its own source of energy for the driving gear train, respectively the switching gear train, only a single barrel is used, which serves as the sole source of energy for the entire train of the thus simplified movement. The resulting third and fourth embodiment of a movement according to the invention, which, according to the description above, have a release mechanism controlled either by means of a step disk 41 mounted on the minute wheel 22 or by means of a cam disk 71 mounted on the intermediate wheel 54 additionally inserted into the gear train, therefore, in view of the above description, don't require any further explanations and are not shown in the accompanying drawings, without this affecting the scope of the present invention also including these embodiments.
A watch according to the present invention has a number of advantages. The release mechanism of a movement according to the invention consists, in particular, only of a control disk, two release levers, each with a first and a second lever arm, and a release wheel, wherein the control disk is mounted on an intermediate pinion which is additionally integrated into the first transmission chain, this resulting in a simple and space-saving design as well as in a safe functioning. In the case of the preferred use of two barrels in the movement, these ensure a safe stepwise switching until the end of the power reserve of the timepiece, wherein the release mechanism realizes a safe control of the switching gear train by the driving gear train. Any amplitude fluctuations in the balance-spring system are thereby kept low. The associated disk setting means, which has a simply designed coupling between the intermediate wheel pinion and the minute-units disk, allows safe adjustment of the time in both directions and can be optionally equipped with a blocking device of the intermediate wheel pinion, which blocks said intermediate wheel pinion when setting the time in the counterclockwise direction. Furthermore, the winding device is robust, can be implemented in a relatively simple manner, and is characterized by a safe operation. The arrangement of the axes of the minute-units and minute-tens disk parallel to each other and inside the hour ring realizes an aesthetically pleasing, digital time display for mechanical timepieces and grants a certain degree of freedom in the arrangement of the time display on the dial of the timepiece.
| Number | Date | Country | Kind |
|---|---|---|---|
| CH 00425/17 | Mar 2017 | CH | national |
