WATCH

Abstract

 The invention relates to a watch comprising a set of mechanisms or machine, a cover which supports the machine and a middle which surrounds said machine. During the setting step, the machine is solidly connected to the cover of the watch and the assembly thus formed is pivot mounted to the middle, such that at least one hand of the watch can be set by rotating the assembly in relation to the middle in a first direction of rotation. The inventive watch also comprises blocking means which block at least one of the hands of the watch in respect of the middle when the aforementioned assembly is being rotated in relation to the middle in a second opposing direction of rotation. Said system enables one hand to be set by rotating the machine in one direction, and the other hand to be set, without moving the first, by rotating the machine in the opposite direction.

Description

[0001] The present invention relates to a watch that comprises a movement or machine, a cover that lends support to said machine, and a middle of the watch-case that surrounds said machine.

BACKGROUND ART

[0002] There are known in the art wristwatches provided with an external crown coupled to a stem that acts mechanically on the hands of the watch, I order to facilitate setting the hands to the right time. This time-setting system isn't very convenient because the stem has to cut through the whole machine and this seriously limits the watch design.

[0003] The stem of a conventional time-setting system limits, for example, the shape of the watch; for instance, it is difficult for conventional automatic watches to be extra-flat, since the rotor must stay above the machine. The stem limits the esthetic appearance of the watch too; for instance, in a transparent watch the stem breaks the harmony of the visible elements.

[0004] Besides, the stem limits the technical possibilities of the machine, since, on one hand, it must cut trough the machine, and, on the other hand, it must cooperate with a mechanism belonging to the machine that rests space therein.

[0005] Swiss patent No. 662235 discloses a wristwatch in which the time-setting and winding crown encircles the watch periphery, surrounding the glass. This invention is intended to provide a mechanism simpler than the traditional one for time-setting, but it doesn't actually eliminate the stem, but just changes its location. Besides, it is necessary to be aware of the position in which the crown stays after each time-setting operation, since should the crown stay in another position it would cause the watch halting. It is clear that this shortcoming is a serious drawback of this system.

SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to provide a watch which does not need any time-setting stem and is simpler and more versatile than known watches.

[0007] Before starting this summary, it is convenient to state precisely the terminology employed in this specification. Hereinafter, the "machine" is an assembly consisting of the principal elements and mechanisms of a watch, which cooperate to drive the hands of the watch and form an unitary block (in this memory the machine is considered a "black box", though, of course, the hands, which are driven by the machine, rotate with respect to the machine when in operation). The "middle" of the watch-case is the middle part of the case, in which the machine is fitted; the middle does not include the watch "cover", which is the bottom of the watch. The "dial" is a plate bearing various markings to show the hours, minutes and seconds, on which the user reads the angular position of the hands.

[0008] In a watch according to the invention, at least during the step of time-setting, the machine and the cover move together and in the cover and the machine are rotatably mounted with respect to the middle, so that at least one hand of the watch can be set on time by rotating the cover and the machine in a first sense of rotation with respect to the middle.

[0009] In this way, by rotating the machine with respect to the middle, it can be obtained for at least one hand of the watch any angular position with respect to the middle. Moreover, the machine can be placed in any position and the watch can have any shape.

[0010] Advantageously, the watch comprises blocking means for blocking at least one hand with respect to the middle when the cover and the machine are rotated in a second sense of rotation opposite the first sense of rotation. That is, this arrangement allows to time-set one hand by rotating the machine in one sense, and to time-set the other hand, without further moving the previous hand, by rotating the machine in the opposite sense.

[0011] In an embodiment, said blocking means comprises a ratchet mechanism arranged between the transmission of movement to the hour hand and the own hour hand. Thus, though it is added a simple ratchet mechanism, it is also subtracted the whole traditional time-setting mechanism, and, overall, the mechanical complexity of the watch is reduced and space is freed in the machine.

[0012] Preferably, said ratchet mechanism comprises a ratchet wheel such that said ratchet wheel and the hour hand move together, and that during the normal operation of the watch said ratchet wheel is frictionally dragged to appropriately rotate, and wherein the ratchet mechanism also comprises at least one pawl intended to engage the ratchet wheel for blocking its rotation in a second sense of rotation. During the normal operation of the watch, the pawl slides over the ratchet wheel, but when the machine is forced to rotate in the second sense of rotation, the pawl blocks the ratchet wheel and the hour hand stays still with respect to the middle, and for keeping rotating the machine, and the minute hand too, in said second sense of rotation, the friction between the ratchet wheel and the mechanism for transmitting rotation to the hour hand must be overcome.

[0013] Advantageously, the ratchet mechanism comprises two claws which engage both sides of the ratchet wheel, one at each side, said claws being fixed to a support plate which is fixed to the middle. This arrangement provides a ratchet mechanism balanced and reliable.

[0014] In an embodiment, the cover comprises a crown which protrudes radially with respect to the middle. In this way, for rotating the machine with respect to the middle it is enough to rotate said crown with one hand, since the middle doesn't move for being attached to the watch belt, which is fixed to the wrist. Alternatively, the middle can be held with one hand and the crown can be rotated with the other hand. Said crown is normally knurled.

[0015] Preferably, the cover comprises a cylindrical portion, such that between said cylindrical portion and the middle there is arranged a gasket which seals the machine. This gasket provides also some friction between the cover and the middle, with enough force to avoid unintentionally rotating the cover with respect to the middle.

[0016] In an embodiment, the cylindrical portion of the cover has a peripheral groove that can fit a plurality of bolts which run through the middle and fix it axially to said cover, but do not prevent said middle from rotating around the machine.

[0017] In an embodiment, between the machine and the cylindrical portion of the cover it is arranged a bearing for supporting said machine. This is a very convenient manner of supporting the machine when, during the watch functioning, the machine rotates with respect to the machine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Some particular embodiments of the present invention will be described in the following, only by way of non-limiting example, with reference to the appended drawings, in which:

figure 1 is a schematic side view of one embodiment;

figure 2 is a schematic view of a mechanism of a conventional watch;

figure 3 is similar to figure 2 and shows a detail of an embodiment;

figure 4 is similar to figure 3 but with some fillings added which represent related elements; and

figure 5 is a top view of a detail of figure 3.

DESCRIPTION OF PARTICULAR EMBODIMENTS

[0019] One embodiment of the invention, as seen in figure 1, applies to a watch provided with only one hand, which completes a turn every twelve hours and marks the hour on a dial.

[0020] In this embodiment, a machine 1 is fixed to a cover 2 which is the watch bottom. The embodiment comprises a middle 3 which encloses the machine 1 and can rotate around it, or vice-versa. A transparent glass 4 for viewing the hour, which is shown by the position of a hand 5 on a dial 6, is fixed to the middle 3, as well as the dial 6 is. The rotation of the hand 5 depends only on the internal mechanisms of the machine 1.

[0021] The cover 2 comprises a cylindrical portion 21 which is provided with a peripheral groove 7 that can fit some bolts 8, normally four, that run through the middle 3 and axially fix it to the cover 2; in other words, said bolts do not prevent the middle from rotating around the cover, but do not allow a significant axial movement of the middle relative to the cover.

[0022] The watch also comprises a gasket 9 between said cylindrical portion 21 and the middle 3, which seals the watch.

[0023] For time-setting the watch it is enough to rotate a crown 22, arranged on the cover 2, which drags the machine 1 and the hand 5, until the hand 5 is over its desired position on the dial 6, which has not moved. Relative rotation between the machine 1 and the middle 3 is subjected to a friction, so that the machine cannot inadvertently rotate relative to the middle.

[0024] Another embodiment is a watch similar to the watch of the previous embodiment but with additional elements, such that a minute hand. In this embodiment, the time-setting is carried in two steps, one for each hand. In the first step the hour hand is set, analogously to the way of the previous embodiment, and in the second step the minute hand is set, by way, for example, of a ratchet which will be described afterwards.

[0025] Before continuing disclosing this embodiment, it is convenient to briefly describe the mechanism which drives the rotation of the minute hand and the hour hand of a conventional watch. This explanation will make reference to figure 2. In the next paragraph the term "wheel" refers to a gear wheel.

[0026] A conventional watch comprises a wheel 11, termed "chaussee" or cannon pinion, which is linked to a first cannon 12 that encapsulates one shaft 10. The first cannon 12, and also the cannon pinion 11, rotates with the shaft 10 by virtue of the friction between them. The cannon pinion 11 engages with a wheel 14 to which a pinion 15 is attached; the pinion 15 engages an hour wheel 16 which is coaxial with the first cannon 12 and can rotate around it by virtue of a second cannon 17. Above a dial 6 there are two hands, a minute hand 20 and an hour hand 25, which mark the time on the dial 6. The minute hand 20 is fixed to the first cannon 12 and rotates following the rotation thereof. The hour hand 25 follows the rotation of the hour wheel 16, the relationship between the teeth of the different wheels and pinions being the appropriate for having a correct ratio between the rotational speed of both hands.

[0027] Now the second embodiment will be disclosed, making reference mainly to figures 3 and 4. The typical elements of a conventional watch as shown in figure 2 are repeated in figures 3 and 4.

[0028] On the cannon 17 there is mounted by friction (with an appropriate tightening) a ratchet wheel 30 which engages a pawl 32 fixedly mounted on a support plate 36, which is fixed to the middle 3. The pawl 32 has two claws 33, one at each side of the ratchet wheel 30, which make the engagement of the pawls to the ratchet wheel. Figure 5 shows the ratchet mechanism. The hour hand 25 now follows the movement of the ratchet wheel 30 and the latter is mounted by friction on the hour wheel 16.

[0029] In normal operation, the watch of this embodiment works as a conventional watch: the minute hand 20 rotates with the first cannon 12 and the hour hand 25 rotates with the ratchet wheel 30 in the sense of arrow A (figure 5), such that the ratchet wheel 30 slides over the claws 33 of the pawl 32, and the ratchet mechanism does not have any mechanical effect.

[0030] Before disclosing the time-setting mechanism it is convenient to remember that, on one hand, the dial 6, the plate 36, the pawl 32 (neglecting the small oscillation of the claws 33) and the middle 3, all follow the same movement, and, on the other hand, the hour hand 25 and the ratchet wheel 30 follow the same movement too, but different from the former. The ratchet wheel 30 is linked by friction to the hour hand 25, but this friction can be overcome by applying enough torque.

[0031] The first step of the time-setting is similar to the one explained for the first embodiment, making reference to figure 1: the hour hand 25 is set in the correct position with respect to the dial by rotating the crown 2 an appropriate angle, but now this rotation must be made in a definite sense, the one indicated by arrow A in figure 5.

[0032] In the second step, the crown 2 is rotated in the opposite sense, the one indicated by arrow B in figure 5, by virtue of what at least one of the claws 33 engages the ratchet wheel 30 and the hour hand 25 stays still with respect to the dial 6. For this rotation to be possible it is necessary to overcome the friction between the ratchet wheel 30 and the hour wheel 16. Thus, the minute hand 20, following the crown 2 and the machine 1, rotates over the dial 6 till the appropriate position, with the hour hand 25 stays still in the position resulting from the first step.

[0033] In figure 4 there are grouped with the same filling the elements which move together in the second step just disclosed. Thus, in figure 4 are represented two blocks with relative movement to each other.

[0034] In sum, the invention provides a time-setting system that gets rid of the stem and its associated mechanism, consequently saving parts and also space in the machine, while only adding a simple ratchet, or similar, mechanism which does not limit the different aspects of designing a watch.

[0035] Although only particular embodiments of the invention have been shown and described in the present specification, the skilled man will be able to introduce variations and modifications without departing from the scope of protection defined by the appended claims.

[0036] For example, other systems for blocking the rotation of one of the hands in the second step of time-setting can be easily conceived.

[0037] Other arrangements for the bolts which axially fix the middle to the cover are easily conceived too, for example an axial arrangement.

[0038] Moreover, the expression "the machine and the cover move together" or "the machine is solidly connected to the cover" is to be understood as limited to the time-setting procedure, as during the normal watch functioning it could be the shaft 10, or an element solidly connected to it, the one which is solidly connected to the cover 2, but since, in this case, during the time-setting said shaft 10 and the machine would be solidly connected, the machine 1 and the cover 2 would then also be solidly connected.

[0039] If, during some stage of the watch functioning, the machine rotates with respect to the cover, one bearing (not shown) may be arranged between the cover and the machine. Since there is no stem, said bearing may be advantageously placed in an orbital arrangement between the machine 1 and the cylindrical portion 21 of the cover 2. In this way, the machine is much better supported than when it leans on a bearing that supports the shaft 10 (or an equivalent element).

Claims

1. Watch that comprises a machine (1), a cover (2) that lends support to said machine (1), and a middle (3) of the watch-case that surrounds said machine (1), characterized in that the machine (1) and the cover (2) move together and in that the cover (2) and the machine (1) are rotatably mounted with respect to the middle (3), so that at least one hand (5;20,25) of the watch can be set on time by rotating the cover (2) and the machine (1) in a first sense of rotation (A) with respect to the middle (3).

2. Watch according to claim 1, wherein it comprises blocking means for blocking at least one hand (25) with respect to the middle (3) when the cover (2) and the machine (1) are rotated in a second sense of rotation (B) opposite the first sense of rotation (A).

3. Watch according to claim 2, wherein said blocking means comprises a ratchet mechanism (30,32,36) arranged between the transmission of movement to the hour hand (25) and the own hour hand (25).

4. Watch according to claim 3, wherein said ratchet mechanism (30,32,36) comprises a ratchet wheel (30) such that said ratchet wheel (30) and the hour hand (25) move together, and that during the normal operation of the watch said ratchet wheel (30) is frictionally dragged to appropriately rotate, and wherein the ratchet mechanism also comprises at least one pawl (32) intended to engage the ratchet wheel (30) for blocking its rotation in a second sense of rotation (B).

5. Watch according to claim 4, wherein the ratchet mechanism comprises two claws (33) which engage both sides of the ratchet wheel (30), one at each side, said claws (33) being fixed to a support plate (36) which is fixed to the middle (3).

6. Watch according to any of the preceding claims, wherein the cover (2) comprises a crown (22) which protrudes radially with respect to the middle (3).

7. Watch according to any of the preceding claims, wherein the cover (2) comprises a cylindrical portion (21), such that between said cylindrical portion (21) and the middle (3) there is arranged a gasket (9) which seals the machine (1).

8. Watch according to any of the preceding claims, wherein the cylindrical portion (21) of the cover (2) has a peripheral groove (7) that can fit a plurality of bolts (8) which run through the middle (3) and fix it axially to said cover (2), but do not prevent said middle (3) from rotating around the machine (1).

9. Watch according to any of the preceding claims, wherein between the machine (1) and the cylindrical portion (21) it is arranged a bearing for supporting said machine (1).

Drawing