CH718918A2 - Watch case comprising a bottom oriented in a predefined angular position, watch comprising said case and method of mounting such a case. - Google Patents

Abstract

The present invention relates to a watch case (100) comprising a middle part (110) comprising a first opening receiving a crystal opposite to a second opening receiving a back (130), the watch case (100) being characterized in that the back (130) is held against an annular bearing surface (112) of the caseband (110) by a threaded ring (140) cooperating by screwing with said caseband (110), the bottom (130) comprising a first indexing means configured to cooperate with a second indexing means (114) with which the middle part (110) is equipped so as to immobilize the said back cover (130) in rotation according to a single angular position with respect to the middle part (110).

Description

Technical field of the invention

The invention relates to the field of watchmaking, and in particular components of a watch case.

More particularly, the invention relates to a watch case comprising a bottom oriented in a predefined angular position, a watch comprising said case and a method of mounting such a case.

Technology background

[0003] The watch cases comprise a middle part on either side of which are arranged a crystal and a bottom.

[0004] The bottom is generally fixed to the caseband by screwing, and for this purpose comprises a thread intended to cooperate with an internal thread made in the caseband.

[0005] This type of attachment does not make it possible to control the orientation of the caseback relative to the middle part, and in particular relative to a vertical axis 12 o'clock - 6 o'clock, when they are attached to each other. .

[0006] Such a drawback is particularly detrimental for aesthetic reasons and of perceived quality, when the background comprises decorative elements or inscriptions.

[0007] The solutions developed by the state of the art are generally complex and expensive to implement.

[0008] In particular, it is known to specifically machine a thread in the caseband and a thread on the back so that they are associated with each other so that when said caseback is fixed to said caseband, the angular position of the latter is known and always identical. However, in practice, this solution presents difficulties both at the level of the manufacturing process and at the level of the after-sales aspect, for example if it is necessary to replace a possibly lost or damaged bottom.

Summary of the invention

The invention solves the aforementioned drawbacks by proposing a solution making it possible to fix a back cover to a middle part in a single predefined relative angular position.

To this end, the present invention relates to a watch case comprising a middle part comprising a first opening receiving a glass, opposite a second opening receiving a bottom, the bottom is held in abutment against an annular bearing surface of the middle part by a threaded ring cooperating by screwing with said middle part, the back comprising a single first indexing means configured to cooperate with a single second indexing means with which the middle part is fitted so as to immobilize the said back in rotation according to a single angular position with respect to to the middle.

[0011] Thanks to these characteristics, the back does not require adjustment of its angular position with respect to the caseband after having been fixed to the caseband insofar as it is locked in rotation in a single predefined position.

The present invention also makes it possible to control the tightening torque of the bottom, and in particular of the ring, since when screwing the ring onto the caseband, the bottom is oriented in the predefined position.

[0013] The orientation of the bottom is achieved with great precision thanks to the cooperation between the first and second indexing means, said indexing means playing a keying role insofar as they make it possible to immobilize the bottom in a single position.

[0014] This feature also guarantees simplicity of production and assembly of the watch case, which contributes to reducing the manufacturing costs of watches comprising this case.

It is understood from the characteristics of the present invention that the first and second indexing means blocks the mobility of the bottom in rotation and that the ring blocks the mobility of the bottom in translation.

[0016] In particular embodiments, the invention may also comprise one or more of the following characteristics, taken in isolation or in all technically possible combinations.

[0017] In particular embodiments, the first and second indexing means are formed by a lug/notch couple.

[0018] In particular embodiments, the caseband comprises an internal thread with which cooperates by screwing an external thread with which the ring is equipped.

[0019] In particular embodiments, the back has a peripheral lip extending radially around the periphery of said back, and being arranged to bear against the annular bearing surface of the middle part.

In particular embodiments, the ring comprises an annular portion comprising the external thread and an end surface by which it bears against the peripheral lip of the bottom.

[0021] In particular embodiments, the peripheral lip extends from a tubular wall materializing an upper end of the back, the tubular wall being engaged in a bore of the caseband.

In particular embodiments, the notch is arranged on the tubular wall and extends axially from a free end of said tubular wall, said notch being configured to cooperate with the lug, said lug being arranged on the bore.

[0023] In particular embodiments, a seal is arranged between the caseband and the back, and is interposed between a shoulder formed by the junction between the tubular wall and the peripheral lip, and an annular recess of the caseband formed at the junction between the annular surface and the bore.

[0024] In particular embodiments, the ring comprises a radial portion connected to the annular portion and having an internal radial surface arranged opposite an annular bearing surface of the bottom.

In particular embodiments, the radial portion of the ring comprises a lower cylindrical surface facing which is arranged a lower cylindrical surface of the bottom of complementary shape.

[0026] According to another object, the present invention relates to a watch comprising a watch movement housed in an internal volume of a watch case as described above, said internal volume being defined between the middle part, the crystal and the back.

[0027] According to yet another object, the present invention relates to a method of mounting a watch case as described above, in which the bottom is engaged in the second opening of the middle part so that the first indexing means cooperates with the second indexing means, then the ring is screwed to the caseband so as to immobilize said back resting against said caseband.

Brief description of figures

Other characteristics and advantages of the invention will appear on reading the following detailed description given by way of non-limiting example, with reference to the appended drawings in which: FIG. 1 represents a cross-sectional view of a watch comprising a case according to a preferred embodiment of the invention; FIG. 2 represents an exploded perspective view from above of the box of FIG. 1 on which a single first indexing means with which the bottom is provided is visible; FIG. 3 represents an exploded perspective view from below of the case of FIG. 1 on which a single second indexing means with which the middle part is equipped is visible.

Detailed description of the invention

[0029] Figure 1 shows a cross-sectional view of a watch 10 comprising a watch case 100 according to the present invention.

The box 100 comprises a middle part 110 comprising a first opening receiving a crystal 120, opposite a second opening receiving a bottom 130; crystal 120, back 130 and middle 110 defining a volume inside which a watch movement is arranged in a manner known to those skilled in the art.

The watch movement and the other watch components used in a case 100 being known to those skilled in the art and not forming part of the present invention, they are not described below.

The box 100 includes a ring 140 adapted to be fixed to the caseband 110 while maintaining the bottom 130 in position against the latter.

The ring has a central through hole through which the bottom is visible, as shown in Figures 1 to 3.

It should be noted that the bottom 130, the ring 140 and the middle part 110 have shapes of geometry of revolution, whose axes of revolution are coaxial, as seen in Figures 2 and 3.

The ring 140 has an external thread 141 by which it is intended to cooperate by screwing with an internal thread 111 made in the middle part 110, at the level of the second opening.

Even more specifically, in the preferred embodiment of the present invention, the ring 140 has, at one of its ends called "upper end", an axial annular portion defined by an end surface 142 connecting an upper cylindrical surface 143 and an outer surface, the external thread 141 being made on the outer surface of the annular portion.

The terms "upper" and "lower" relate in this text to the orientation in space of a box 100 as shown in Figures 1 to 3, the glass 120 being arranged above the background 130.

[0038] In addition, the bottom 130 has a peripheral lip 131 extending radially around the periphery of the bottom 130, from a tubular wall 132 materializing an upper end of said bottom 130, said peripheral lip 131 being arranged to rest against an annular bearing surface 112 of the middle part 110. Furthermore, the tubular wall 132 is engaged in a bore 113 of the middle part 110 when the back is fixed to said middle part 110.

Alternatively, the bottom 130 may comprise a plurality of peripheral lips (not shown in the figures) each extending radially around a portion of the periphery of the bottom 130, in the same plane.

As shown in the sectional view of Figure 1, the ring 140 is configured so as to bear against the peripheral lip 131 of the bottom 130 by the end surface 142 of the annular portion, when said ring 140 is screwed with caseband 110.

Advantageously, the bottom 130 comprises a single first indexing means configured to cooperate with a single second indexing means with which the caseband 110 is provided, so as to immobilize said bottom 130 in a single angular position with respect to the middle part 110 when the ring 140 fixes the back 130 against said middle part 110.

[0042] More particularly, the first and the second indexing means are formed by a lug/notch couple.

In the embodiment shown in Figures 2 and 3, the bottom 130 has a notch 133 arranged on the tubular wall 132, said notch extending axially from a free end of said tubular wall 132.

The notch 133 is intended to cooperate with a lug 114 extending inside the middle part 110. More particularly, the lug 114 is arranged on the bore 113 and has a shape complementary to that of the notch 133, to within mechanical play, so as to be able to engage inside the notch 133 when the tubular wall 132 of the bottom 130 is introduced into the bore 113.

It should be noted that in other embodiments of the invention not shown in the figures, the notch 133 can be arranged in the caseband 110 and the lug 114 can be arranged on the bottom 130 , analogously to the preferred embodiment shown in the figures.

The ring 140 comprises a radial portion having an internal radial surface 144 intended to be arranged opposite an annular bearing surface 134 of the back 130, when the ring 140 is screwed to the thread 111 of the middle part 110. The radial portion is connected to the annular portion, as shown in Figure 1.

[0047] Advantageously, the fixing ring 140 can possibly bear against the annular bearing surface 134 peripheral of the bottom 130 in addition to bearing against the peripheral lip 131.

This annular surface 134 is connected to the peripheral lip 131 by an upper cylindrical surface 135 intended to be arranged facing the upper cylindrical surface 143 of the annular portion of the ring 140, when the bottom 130 is fixed to the middle 110.

Furthermore, a seal 150 is arranged between the middle part 110 and the bottom 130, and is interposed between a shoulder formed by the junction between the tubular wall 132 and the peripheral lip 131, and an annular recess of the middle part 110 formed at the junction between the annular surface 112 and the bore 113.

The radial portion of the ring 140 has a lower cylindrical surface 145 opposite which is arranged a lower cylindrical surface 136 of the bottom 130 of complementary shape.

When fixing the bottom 130 on the middle part 110, the bottom 130 is first engaged in the second opening of the middle part 110 so that the lug 114 cooperates with the notch 133, the tubular wall 132 of the back 130 being engaged in bore 113 of middle part 110 until peripheral lip 131 is arranged to bear against annular bearing surface 112.

The bottom 130 and the middle part 110 then form a housing defined between the upper cylindrical surface 135, the peripheral lip 131 and the internal thread 111 of the middle part 110, in which the ring 140 is intended to be engaged.

The ring 140 is then caused to cooperate with the internal thread 111 of the middle part 110, until the peripheral lip 131 is tightened against the annular surface 112 and reaches a predetermined tightening torque sufficient to fix rigidly, that is to that is to say, according to a mechanical connection of the embedding type, the back 130, the ring 140 and the middle part 110 together.

Advantageously, the ring 140 may include a fillet or a chamfer at the junction between the upper cylindrical surface 143 of the annular portion and the end surface 142, and the bottom 130 may also include a fillet or a chamfer at the junction between the annular surface 134 and the upper cylindrical surface 135, so as to facilitate the introduction of the ring 140 within the housing formed between the bottom 130 and the middle part 110.

In addition, a chamfer or a fillet can be made at the junction between the cylindrical surface of the radial portion of the ring 140 and the inner radial surface 144 of said radial portion.

Preferably, the ring 140 has on an outer face opposite to the inner volume of the watch case 100, radial notches 146 intended to cooperate with a tool manipulated by a user. Thanks to the radial notches 146, the ring 140 can be screwed or unscrewed by manipulation of the tool, so as to fix the ring 140 and the bottom 130 to the caseband 110, or on the contrary, so as to separate them from said caseband 110 .

Claims (12)

1. Watch case (100) comprising a middle part (110) comprising a first opening receiving a crystal (120), opposite a second opening receiving a bottom (130), the watch case (100) being characterized in that the back (130) is held against an annular bearing surface (112) of the middle (110) by a threaded ring (140) cooperating by screwing with said middle (110), the back (130) comprising a single first means of indexing (133) configured to cooperate with a single second indexing means (114) with which the middle part (110) is provided so as to immobilize the said back (130) in rotation according to a single angular position with respect to the middle part (110) . 2. Watch case (100) according to claim 1, in which the first and second indexing means are formed by a lug/notch pair (114,133). 3. Watch case (100) according to one of Claims 1 or 2, in which the middle part (110) comprises an internal thread (111) with which an external thread (141) with which the ring (140) is provided, cooperates by screwing. . 4. Case (100) watch according to one of claims 1 to 3, wherein the bottom (130) has a peripheral lip (131) extending radially around the periphery of said bottom (130), and being arranged to rest against the annular surface (112) of the caseband (110). 5. Case (100) watch according to claims 3 and 4, wherein the ring (140) has an annular portion comprising the external thread (141) and an end surface (142) by which it bears against the lip peripheral (131) of the bottom (130). 6. Case (100) watch according to claim 4 or 5, wherein the peripheral lip (131) extends from a tubular wall (132) materializing an upper end of the bottom (130), the tubular wall (132) being engaged in a bore (113) of the caseband (110). 7. Case (100) watch according to claims 2 and 6, wherein the notch (133) is arranged on the tubular wall (132) and extends axially from a free end of said tubular wall (132), said notch (133) being configured to cooperate with the pin (114), said pin (114) being arranged on the bore (113). 8. Watch case (100) according to claim 6, in which a seal (150) is arranged between the middle part (110) and the bottom (130), and is interposed between a shoulder formed by the junction between the tubular wall ( 132) and the peripheral lip (131), and an annular recess of the caseband (110) formed at the junction between the annular surface (112) and the bore (113). 9. Case (100) watch according to claim 5, wherein the ring (140) comprises a radial portion connected to the annular portion and having an inner radial surface (144) arranged vis-à-vis an annular surface (134) of the bottom (130). 10. Watch case (100) according to claim 9, in which the radial portion of the ring (140) comprises a lower cylindrical surface (145) facing which is arranged a lower cylindrical surface (136) of the bottom (130) complementary form. 11. Watch (10) characterized in that it comprises a watch movement housed in an internal volume of a watch case (100) according to one of claims 1 to 10, said internal volume being defined between the middle part (110 ), ice (120) and bottom (130). 12. A method of mounting a watch case (100) according to one of claims 1 to 10, in which the bottom (130) is engaged in the second opening of the middle part (110) so that the first means of indexing (133) cooperates with the second indexing means (114), then the ring (140) is screwed to the caseband (110) so as to immobilize said bottom (130) resting against said caseband (110).