Device for setting the hands of a clock

Abstract

The present invention relates to a device for setting the hands of a clock comprising a first hand, a second hand, a clockwork mechanism, and a crown (1) with a winding stem (2). The crown is provided for switching between a normal position and an adjustment position for setting the first hand. It comprises a gear (3), a pawl (4), and a spring (5). In the adjustment position, the position of the second hand is static. When the crown is turned, the gear rotates, and the pawl (4) slides along the teeth of the gear as the gear rotates, allowing the first hand to be adjusted only in discrete steps. The proposed solution enables precise and incremental adjustment of the first hand and prevents asynchrony between the first and second hands.

Description

[0001] The present invention relates to a device for setting the hands of a clock, in particular a setting mechanism for a clockwork of such a clock for synchronously setting two hands.

[0002] Clock movements, particularly mechanical ones, are known from the prior art in which – depending on the position of the crown – the time can be set or the clock's mainspring wound by turning the crown. For example, to set the time, the crown is moved from a normal position to a setting position to connect a winding stem to the clock's hands.

[0003] A disadvantage of conventional clock mechanisms is that when setting the hands, their relative positions can change undesirably, causing them to rotate asynchronously and negatively affecting the accuracy of the time display. For example, the second hand might be pointing exactly at 12, while the minute hand is positioned between two minute markers. When setting the clock, the crown can be turned continuously, thus continuously adjusting the minute and hour hands. This can lead to asynchronous hand positions between the second and minute hands. It's conceivable, for instance, that the minute hand might point precisely to a whole-number minute marker, while the second hand doesn't point to exactly zero seconds, i.e., it might not be on the 12 o'clock position on the clock face.

[0004] Against this background, the present invention aims to provide a solution that avoids the aforementioned disadvantages and creates an improved control mechanism for clockworks.

[0005] According to the invention, this problem is solved by a device for setting the hands of a clock comprising a first hand, a second hand and a crown with a winding shaft, wherein the crown is provided for switching between a normal position and a setting position for setting the first hand, comprising a gear, a pawl and a spring, wherein in the setting position the position of the second hand is static, when the crown is turned a rotation of the gear, and a sliding of the pawl along the teeth of the gear is provided when the gear is turned, whereby the first hand can only be adjusted in discrete steps.

[0006] According to the invention, when the gear rotates, the pawl slides along the teeth of the gear. The spring presses the pawl into detent positions. Thus, the crown can only be rotated in discrete steps. These discrete steps are defined by the gear.

[0007] A clock has at least two hands, usually a minute hand and a second hand, which indicate the time. A third hand may also be present. This third hand can be an hour hand, indicating the time in hours. Each hand has a specific function and must be precisely adjusted to display the correct time.

[0008] Optionally, the clockwork can be a mechanical clockwork. A mechanical clockwork within the meaning of the present invention can be understood as the gearing of a clock, which is mechanically driven to move the hands. It is driven by a spring and uses gears, springs, and other mechanical components to ensure a continuous and precise movement of the hands.

[0009] The movement can optionally be an automatic movement. An automatic movement uses the kinetic energy generated by the wearer's movements to wind a spring. This stored energy is then released to power the watch's hands. The mechanism often includes a rotor weight that rotates with movement and, via a transmission system, continuously winds the spring, thus eliminating the need for manual winding.

[0010] The clock movement can optionally be a quartz movement. A quartz movement uses an electronic oscillator, stabilized by a quartz crystal, to generate highly precise time oscillations. These oscillations are converted into electrical signals and control a small stepper motor, which drives the clock's mechanical gears. This type of movement requires a battery as a power source to continuously supply the oscillator and motor with current.

[0011] A crown can be an external control element that a watch user can manually turn. The winding stem connects the crown to the movement and can be used to wind the watch (i.e., to wind a spring in the movement) or to set the watch hands. It is equipped with a setting mechanism consisting of at least one gear, a pawl, and a spring, with the crown allowing the user to select a winding position and a neutral position.

[0012] In the setting position, the position of the first hand can be adjusted by turning the crown. The second hand, for example, the seconds hand, does not change its position during the setting process. The crown can be turned to set the first hand. As the gear is turned, the pawl slides along the teeth of the gear. The spring pushes the pawl into detent positions, which are located between the teeth of the gear. Thus, the first hand can be set in one step or in discrete increments. The setting mechanism can be connected to the crown. The user can set a setting position as well as a normal position for the crown. In the setting position, the user can change the position of the minute hand by turning the crown. In the normal position, the user can wind the spring by turning the crown.

[0013] The gear, pawl, and spring ensure that the movement of the hands is controlled and occurs in specific increments. A gear is a rotating machine element with teeth that is operatively connected to other gears in the clockwork mechanism. In the present invention, the gear can be moved by turning the crown and serves as a transmission element that influences the movement of the pawl. The pawl is a movable part that can engage with the teeth of the gear. The spring provides the necessary restoring force so that the pawl can return to its starting position after each engagement. When the crown is turned, the pawl can slide over the teeth of the gear, enabling the hands to be set in a specific increment.

[0014] In this way, the solution according to the invention ensures that the synchronization of the two hands is maintained during the setting process. With regard to clocks, synchronization describes the agreement of the hands' movements, whereby the hands of a clock are synchronized when their movements are coordinated so that the correct time can be displayed. In the present invention, synchronization can refer to the fact that the first and second hands can remain in sync at all times. Even if the first hand is moved abruptly during setting, the setting mechanism ensures that the position of the second hand remains unchanged. This prevents a temporal discrepancy from arising between the hands, thus ensuring that the clock remains accurately set.

[0015] Preferably, the first hand is a minute hand and the second hand is a second hand. In this way, the solution according to the invention ensures that the synchronization of the second hand with the minute hand is maintained during the setting process. The minute hand is the hand of the clock that indicates the time in minutes. The minute hand can move across the dial and complete one full rotation in one hour. The second hand can indicate the time in seconds and complete one full rotation in one minute.

[0016] In a preferred embodiment, the minute hand is set in increments of an integer multiple of a minute. The adjustment is discrete and not continuous. The second hand cannot change its position during the adjustment process. This ensures that the relative position of the two hands to each other remains unchanged. This incremental movement can occur at predefined intervals, in integer multiples of a minute. This means, for example, that the minute hand can only be moved by exactly one, two, three, or more minutes. This type of adjustment prevents erroneous or inaccurate positioning of the minute hand. Therefore, it is not possible to adjust the minute hand by a fraction of a minute (for example, half a minute or a quarter of a minute).The movement only occurs in multiples of whole minutes (e.g. 1 minute, 2 minutes, 3 minutes, etc.).

[0017] Preferably, the gear is movably mounted on the winding stem, and the pawl is attached to a stationary part of the watch so that the pawl can engage the teeth of the gear. The spring can be mounted to a stationary part of the watch. The spring pushes the pawl toward the gear. The winding stem can rotate in its normal position without the gear rotating with it. The gear can rotate but cannot move axially or radially. The pawl is attached to a stationary part of the watch and engages the teeth of the gear. The spring can be attached to the watch and push the pawl onto the gear.

[0018] In a preferred embodiment, the end face of the gear can be configured as a first functional surface, and a second functional surface can be configured on the winding shaft. The end face of a gear is the flat surface that is perpendicular to the axis of the gear. This can be one of the two parallel surfaces of the gear that border the gear rim. The tooth flanks run radially to the axis of rotation. The two functional surfaces are opposite each other and can be moved towards each other to engage.

[0019] The first functional surface and the second functional surface can connect with each other in the set position, so that the gear can rotate with the winding shaft when the winding shaft is turned.

[0020] In a further preferred embodiment, at least one of the two functional surfaces is designed as a spring element, so that in the set position the two functional surfaces are connected by a frictional connection. It is conceivable that one of the spring elements is a disc spring. A disc spring is a special type of spring that has the shape of a flat, conical disc. It is characterized by its special geometry, which allows it to yield elastically under load. The disc spring's function is based on the fact that it is compressed under pressure, thereby developing a restoring force that is proportional to the deformation. In this way, high forces can be absorbed and released in a small space with a compact design. Due to its special geometry, a disc spring can generate progressive spring characteristics, meaning that the resistance to a load increases with increasing deformation.This enables efficient power storage and transmission, making it ideal for applications where high loads need to be absorbed in a controlled manner in a limited space.

[0021] In a further preferred embodiment, the two functional surfaces are designed as friction surfaces, so that in the fixed position, the connection between the two functional surfaces is a friction-fit connection. A friction-fit connection can be created when two surfaces are held together by frictional force. In contrast to a form-fit connection, where the shape of the components prevents slippage, in a friction-fit connection, adhesion is generated by the friction between the surfaces. This type of connection arises from the pressure that holds the two functional surfaces together and the friction that prevents their movement relative to each other. In this way, torque can be transmitted continuously and without additional mechanical elements. Since the connection is created by friction, it can be easily released or adjusted without the need for a form-fit.This allows for flexible and reversible power transmission.

[0022] In a further preferred embodiment, the two functional surfaces are designed as bevel gears, so that in the operating position, the connection between the two functional surfaces is a positive-locking connection. A spur gear is a special type of gear in which the teeth run parallel to the axis of rotation of the gear. A positive-locking connection is a mechanical connection in which two components are connected to each other by their shape in such a way that they interact without play. In a positive-locking connection, the interlocking shapes—in this case, the teeth of the spur gears—prevent relative displacement of the parts. In this way, precise and low-loss power transmission is enabled.Since the teeth of the spur gears mesh directly with each other, a high efficiency is achieved in the transmission of torque without slippage or backlash, which is particularly advantageous in applications with high requirements for accuracy and efficiency - as is the case here.

[0023] Preferably, the gear is rotatably mounted on a stationary part of the watch and a second gear is fixedly mounted on the winding shaft, wherein in the normal position the two gears are not connected to each other, wherein in the setting position the two gears are positively connected to each other and the pawl engages in the gear in the setting position and the normal position.

[0024] Further details, features, and advantages of the invention are explained in more detail with reference to the following exemplary embodiments. The figures merely illustrate exemplary embodiments of the invention, which do not limit the inventive concept.

[0025] This shows: Fig. 1a the normal position in a first embodiment of the device according to the invention; Fig. 1b the positioning position in the first embodiment of the device according to the invention; Fig. 2a the gear, the pawl and the spring in an isometric view; Fig. 2b the gear, the pawl and the spring in a side view; Fig. 3a the functional surface of the gear; Fig. 3b the functional surface of the elevator shaft; Fig. 3c the functional surface of the gear for a force-fit connection; Fig. 3d the functional surface of the gear for a friction-fit connection; Fig. 3e the functional surface of the gear for a positive locking connection; and Fig. 4 a second embodiment of the adjusting mechanism according to the invention.

[0026] Fig. Figure 1a shows the normal position in a first embodiment of the device according to the invention. The crown 1 is connected to the winding shaft 2. The gear 3 is movably mounted on the winding shaft.

[0027] The pawl 4 is attached to a stationary part (not shown) of the watch in such a way that it can engage the teeth of the gear 3. The spring 5 then pushes the pawl 4 into a detent position. In the normal position, there is no fixed connection between the gear 3 and the winding stem 2. The winding stem 2 rotates when the crown 1 is turned, without the gear 3 moving.

[0028] The first functional surface 6 of the gear is also shown in the illustration. Opposite it is the second functional surface 7 of the winding shaft (in Fig. 1a (not visible) is formed. In the normal position, functional surfaces 6 and 7 do not touch. Crown 3 is in the normal position in the depressed state.

[0029] Fig. Figure 1b shows the setting position in a first embodiment of the device according to the invention. The setting position is adjusted using the crown 1, and the winding shaft 2 is connected to the gear 3. In the setting position, the crown 1 is in the pulled-out state, and the functional surfaces are in contact, ensuring a connection between the gear and the winding shaft 2.

[0030] When the crown 1 is turned in the setting position, the winding stem 2 rotates, and with it the gear 3. The pawl 4 engages the teeth of the gear 3, and when the crown 1 is turned, and thus the winding stem 2 and the gear 3 also rotate, the resistance of the spring 5, which presses against the gear 3, must be overcome, and the pawl 4 slides off the teeth of the gear 3, so that the crown 1 only jumps into the next detent position between two teeth and cannot be turned continuously.

[0031] Fig. Figure 2a shows the gear 3, the pawl 4, and the spring 5 in an isometric view. The spring 5 presses the pawl 4 into the tooth gap, thus providing a restoring force. When the gear 3 is rotated, this restoring force must be overcome, and the pawl 4 slides upwards along a tooth flank of a tooth of the gear 3 until it passes the tooth tip of the tooth of the gear 3, before sliding down into the next tooth gap.

[0032] The spring 5 can be a compression spring, tension spring, torsion spring, leaf spring, coil spring, gas spring, or rubber spring. It can be located above or below the pawl 4. Alternatively, the spring 5 can be positioned as a torsion spring on the pivot axis of the pawl 4. The number of teeth on the gear 3 depends on the gear ratio of the hour hand to the crown 1 and the gear ratio of the crown 1 to the gear 3.

[0033] The number of teeth of gear 3 can be calculated using the following formulas 1.1 to 1.3, where i x the translation of crown 1 to minute hand, i y the translation from crown 1 to gear 3, U h the revolutions of the minute hand required to set one hour, U k the turns of crown 1 required to set one hour, U r the revolutions of gear 3 required to set an hour and z r Represent the number of teeth of gear 3. ix=UhUk iy=UkUr zr=ix∗iy∗60

[0034] Fig. Figure 2b shows a side view of the gear 3, the pawl 4, and the spring 5. Alternatively, the spring 5 can be arranged below the pawl 4, in which case the spring 5 is a tension spring. The pawl 4 engages in the gap between two teeth of the gear 3. The spring 5 pushes the pawl towards the gear 3.

[0035] Fig. Figure 3a shows the first functional surface 6. The first functional surface 6 is located on the end face of the gear 3. When the normal position is set, the functional surfaces 6 and 7 are not connected to each other. When the adjustment position is set by pulling the crown, the first functional surface 6 and the second functional surface 7 come into contact with each other. If the crown, and thus the winding stem 2, is rotated in the adjustment position, the gear 3 rotates with it, since the gear 3 is connected to the winding stem 2 via the connection between the two functional surfaces 6 and 7 in the adjustment position.

[0036] Fig. Figure 3b shows the second functional surface 7. The second functional surface 7 is mounted on a flange on the winding shaft 2, which is either fixed to the winding shaft 2 or is part of the winding shaft 2. When the crown 1, which is connected to the winding shaft, is pulled out, the second functional surface 7 is moved towards the first functional surface 6 until the two functional surfaces come into contact and are connected. Therefore, when the crown is turned in setting mode, the second functional surface 7 rotates with the winding shaft 2. Since the two functional surfaces 6 and 7 are connected in setting mode, the gear 3 also rotates when the crown is turned in setting mode.

[0037] Fig. Figure 3c shows the first functional surface 6, on which a disc spring 8 is embossed to create a force-fit connection. It is possible that, alternatively or additionally, a disc spring is formed on the second functional surface 7. Thus, it is possible that the spring is arranged on only one of the two functional surfaces or that there is a spring on each of the two functional surfaces.

[0038] The disc spring 8 is compressed during movement from the normal position to the set position, thereby exerting a spring force on the second functional surface 7. This compression of the disc spring 8 exerts pressure on the second functional surface 7, creating a frictional connection between the gear 3 and the winding shaft 2. Alternatively, instead of a disc spring 8, another spring, such as a compression spring or a rubber spring, can be arranged on one of the two functional surfaces.

[0039] Fig. Figure 3d shows the functional surface 6 of the gear 3, which is designed to create a friction-fit connection. This diagram schematically shows a roughened surface 9, which is designed to provide a suitable coefficient of friction to ensure the required static friction. The coefficient of friction is suitable if, in the set position, when the crown 1 is turned, the gear 3 can rotate freely with the winding stem 2.

[0040] When the normal position is moved to the operating position, the functional surfaces of the gear 3 and the winding shaft 2 come into direct contact. This generates a contact pressure that presses the two surfaces against each other, thus creating a frictional connection between the two functional surfaces 6 and 7. This contact pressure ensures that the two components are firmly connected and can move without slippage.

[0041] As soon as the winding stem 2 is moved by turning the crown 1, the gear 3 is also moved due to the generated friction, so that the rotational motion of the winding stem 2 is effectively transferred to the gear 3. This enables a smooth and controlled transmission of the motion from the winding stem 2 to the gear 3. The choice of material for the functional surface is irrelevant as long as a suitable coefficient of friction is achieved.

[0042] Fig. Figure 3e shows the functional surfaces of the gear 3 and the winding shaft 2, which are designed to create a positive-locking connection. On both functional surfaces, bevel gears 10 and 11 are arranged, their teeth being matched to mesh. In the operating position, the teeth of the bevel gear 10 on the first functional surface 6 therefore engage with the corresponding teeth of the bevel gear 11 on the second functional surface 7.

[0043] This interlocking action creates a positive connection that ensures the transmission of rotary motion without slippage and with high precision. The positive connection ensures that the gear 3 and the winding shaft 2 are firmly linked, allowing every rotary movement of the winding shaft 2 to be transmitted directly and without delay to the gear 3.

[0044] Fig. Figure 4 shows a second embodiment of the adjusting mechanism according to the invention. Here, the gear 3, the pawl 4, and the spring 5 are arranged on a plate 13 of the watch. Furthermore, a second gear 12 is arranged on the winding shaft 2. The second gear 12 is slidably but not rotatably mounted on the winding shaft 2. The second gear 12 rotates with the winding shaft 2, both when the adjusting position and when the normal position are set. Fig. Figure 4 omits the illustration of the crown. If it were shown, the crown would be located on the far right of the illustration and would be mounted on the winding stem 2. When the crown is pulled out, it enters the setting position. Turning the crown in the setting position moves the watch hands. When the crown is pushed in, it enters the normal position. Turning the crown in the normal position winds the watch's mainspring.

[0045] In the normal position, the two gears 3 and 12 are not connected. By moving the mechanism from the normal position to the setting position, the engagement of the teeth of the first gear 3 with the teeth of the second gear 12 creates a positive connection between the teeth of the first gear 3 and the teeth of the second gear 12. Consequently, the winding shaft 2 can only be rotated in increments, rather than continuously, because the pawl 4 and the spring 5 exert a restoring force that must be overcome for each increment. The mechanism forces the winding shaft 2 to rotate in discrete steps, similar to what already occurred with respect to the Fig. 2a and Fig. 2b is described.

[0046] The position of the first and second gears 3, 12 is irrelevant, as long as the teeth of both gears 3, 12 mesh in the set position. It is also conceivable that further gears are arranged between the first gear 3 and the second gear 12.

[0047] The figures described above and the embodiments explained in connection with them serve only to illustrate the invention and are not limiting to it. Reference symbol list: 1 crown 2 elevator shaft 3 gear 4 jack 5 springs 6 First functional area 7 Second functional area 8 spring element 9 friction surface 10 First bevel gear 11 Second bevel gear 12 Second gear 13 circuit boards

Claims

Device for setting the hands of a clock comprising a first hand, a second hand, a clockwork and a crown (1) with a winding shaft (2), wherein the crown is provided for switching between a normal position and a setting position for setting the first hand, comprising a gear (3), a pawl (4) and a spring (5), wherein in the setting position the position of the second hand is static, when the crown is turned a rotation of the gear, and a sliding of the pawl (4) along the teeth of the gear is provided when the gear is turned, whereby the first hand can only be adjusted in discrete steps. Device according to claim 1, wherein the first pointer is a minute pointer and the second pointer is a second pointer. Device according to claim 2, wherein, during the setting position, an adjustment of the minute hand by an integer multiple of one minute is provided. Device according to one of claims 1 to 3, wherein the gear is movably mounted on the winding shaft and the pawl (4) is attached to a non-moving part of the watch in such a way that the pawl (4) can be brought into engagement with the teeth of the gear. Device according to claim 4, wherein an end face of the gear represents a first functional surface (6) and wherein a second functional surface (7) is formed on the winding shaft, wherein in the position the two functional surfaces come into contact with each other, so that the gear rotates with the winding shaft when the winding shaft is rotated. Device according to claim 5, wherein spring elements (8) are arranged on at least one of the functional surfaces, which are provided to achieve a force-fit connection in the positioning position. Device according to claim 5, wherein the functional surfaces are designed as friction surfaces (9) which are provided to achieve a friction-fit connection in the positioning position. Device according to claim 5, wherein the functional surfaces are designed as bevel gears (10, 11) which are provided to achieve a positive locking connection in the positioning position. Device according to claim 1, wherein the gear is rotatably mounted on a stationary part of the watch and wherein a second gear (12) is arranged non-rotatably on the winding shaft and wherein in the normal position the two gears are not connected to each other, wherein in the setting position the two gears are positively connected to each other and in the setting position and in the normal position the pawl (4) is provided to engage the gear.

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