EP0654717A1 - Timepiece with a device for fixing a detachable piece to a support and method for fastening said piece to said support - Google Patents

Abstract

The invention relates to a timepiece having a body or support on which may be held, in a removable manner, a detachable piece. The invention also relates to a method for fastening this piece to this body or support. The timepiece is characterised in that the means for fixing the detachable piece to the body or support consist of at least one revolving lock (10) which is anchored permanently into the actual material of the body or support (2) with axial immobilisation provided by this material. <IMAGE>

Description

The present invention relates to a timepiece comprising a frame on which is detachably held, and by means of a specific fixing device, an insert.

Furthermore, this invention relates to a method of assembling such an insert on a frame of the aforementioned type.

More particularly, the invention relates to a timepiece and an assembly method, in which the frame is made of a synthetic material, said insert being made of any material, for example a metallic material.

It will also be specified that in a particular application, the insert can advantageously be constituted by a protective plate pressed against the frame, and attached to it to protect some of the fragile components of said timepiece.

In conventional timepieces, such protective plates are detachably held in place by screws whose thread is engaged in the synthetic material constituting the frame.

This arrangement has many drawbacks which affect the quality and durability of the timepiece.

In addition, this arrangement can lead, during disassembly and reassembly of the insert on the frame, to damage of components by the fixing device.

Indeed, in timepieces whose frame is made of synthetic material, such as for example plastic, the operations of assembly, disassembly and reassembly of the added parts, such as plates of protection of the type mentioned above, lead to the progressive tearing of the nets formed in the synthetic material. Thus, the number of disassembly / reassembly operations of the plate on the frame must be relatively limited.

In addition, since it is very difficult to measure the clamping forces which are applied when the screw is replaced by hand in the hole which has been tapped by the screw itself in the frame (self-tapping screw), it sometimes happens that this effort is significantly higher than the shear resistance of the threads and, during the first reassembly, this excessive effort can destroy the threads and can make the screw locking action ineffective. plate.

It will further be specified that, during these operations, the screws which are very small may be lost by the operator.

In addition, many components being arranged very compactly in the timepiece and some of them, such as for example the coil, not necessarily being covered by the protective plate, the tool of the operator who is at height with respect to the plate, can slip during the installation of the screw (s), and come to injure, for example, the wires of the coil and seriously damage this coil.

It is therefore understood that this type of attachment is not satisfactory for the removable assembly of an insert on a frame of a timepiece in particular forming a plate of synthetic material.

Furthermore, it has been proposed to provide, directly on the insert, fixing members operating by snap-fastening. However, in view of the dimensions of the components in question here, these members present real manufacturing difficulties and have an insecure operation, because of the low tolerances required for the operation of this device. type of device and difficulties in ensuring such low tolerances in the manufacture of plastic frames.

Thus, the object of the present invention is to respond to the aforementioned drawbacks by providing a timepiece in which the above-mentioned insert is held on the frame by removable fixing means capable of withstanding several disassembly and reassembly while retaining their reliability, and whose installation on the frame, as well as the subsequent disassembly and reassembly operations, are not likely to injure fragile components of the timepiece.

To this end, the subject of the invention is a timepiece of the type comprising a body or frame on which an attached piece is detachably held, such as for example a protective plate, this piece being held on the body or frame by fixing means integral with the body or frame which can rotate while remaining at a constant height relative to the body or frame to allow release of said insert and the release thereof, this invention being characterized in that the fixing means consist of at least one latch which is fixedly and permanently anchored in the same material of the body or frame, with an axial immobilization with respect thereto.

• à ménager un avant-trou sur ledit corps ou bâti,
• à fournir au moins un verrou de fixation destiné à maintenir une pièce rapportée sur le corps ou bâti, ce verrou ayant au moins un épaulement et au moins une aile de blocage, et
• à introduire ledit verrou dans l'avant-trou du corps ou bâti tout en déformant la matière constituant ledit corps ou bâti pour l'amener à recouvrir ledit épaulement, afin de maintenir ledit verrou en place par la matière même du corps ou bâti, le verrou dans cette position étant apte à maintenir ladite pièce rapportée.

This invention also relates to a method of assembling an insert on a body or frame of a timepiece, characterized in that it consists:

• to provide a pilot hole on said body or frame,
• providing at least one fixing lock intended to hold an insert on the body or frame, this lock having at least one shoulder and at least one locking wing, and
• to introduce said lock into the pilot hole of the body or frame while deforming the material constituting said body or frame to cause it to cover said shoulder, in order to hold said lock in place by the material of the body or frame, the lock in this position being able to maintain said insert.

• la figure 1 est une vue en coupe faite selon la ligne I-I de la figure 2, et représentant une pièce d'horlogerie montrée ici de façon partielle, cette pièce étant munie de moyens de fixation, selon un premier mode de réalisation de l'invention, qui sont montrés dans leur position de blocage d'une pièce rapportée sur un bâti de ladite pièce d'horlogerie,
• la figure 2 est une vue de dessus de la figure 1, montrant de façon partielle la pièce rapportée montée sur ledit bâti,
• la figure 3 est une vue en coupe faite selon la ligne III-III de la figure 4, et représentant les moyens de fixation de la figure 1, mais dans leur position de déverrouillage de ladite pièce rapportée,
• la figure 4 est une vue de dessus de la figure 3,
• la figure 5 est une vue similaire à la figure 1, mais représentant un deuxième mode de réalisation de l'invention,
• la figure 6 est une vue en coupe partielle faite selon la ligne VI-VI de la figure 5, et
• la figure 7 est une vue similaire à la figure 3, mais représentant l'invention selon un troisième mode de réalisation.

Other characteristics and advantages of the present invention will appear on reading the detailed description which will be made of two embodiments of the invention, in the light of the appended drawings given here only by way of examples, and in which:

• Figure 1 is a sectional view taken along line II of Figure 2, and showing a timepiece shown here partially, this piece being provided with fixing means, according to a first embodiment of the invention , which are shown in their blocking position of an insert on a frame of said timepiece,
• FIG. 2 is a top view of FIG. 1, showing partially the attached part mounted on said frame,
• FIG. 3 is a sectional view taken along line III-III of FIG. 4, and showing the fixing means of FIG. 1, but in their unlocked position of said insert,
• FIG. 4 is a top view of FIG. 3,
• FIG. 5 is a view similar to FIG. 1, but showing a second embodiment of the invention,
• FIG. 6 is a partial sectional view taken along line VI-VI of FIG. 5, and
• Figure 7 is a view similar to Figure 3, but showing the invention according to a third embodiment.

Referring now to FIG. 1, a timepiece according to the invention will be described below, identified by the general reference 1.

The timepiece 1 comprises a body 2 forming, for example, a frame, made of a synthetic material, in particular of a plastic material, such as phenylene polysulphide (PPS) or in a nonlimiting manner of another synthetic material.

On the body or frame 2 which, in the application shown, constitutes a plate, is mounted an excitation coil 4, shown here in section very schematically.

In addition, on this same frame 2 is removably mounted an insert 6 forming here, for example, a so-called protection plate intended either to protect some of the components (not shown) of the timepiece 1 , or to give this room a particular aspect.

We see that in this embodiment, the protective plate 6 does not entirely cover the coil 4 because of the outside diameter of this coil which must be as large as possible, for reasons of energy supplied, while the thickness movement should be as small as possible.

The timepiece 1 according to the invention further comprises fixing means 8 which are integral with the frame 2 and which hold in place firmly, but removably, the insert 6.

Advantageously, these fixing means 8 consist of one or more latches 10 (only one being shown here) which are permanently anchored in the very material of the body or frame 2, with an axial immobilization, relative to this body or frame, provided by this material, these locks being able to rotate in the body or frame.

As will be understood hereinafter, this or these rotary locks 10 can be turned in the frame 2 while remaining at a constant height with respect thereto. It will also be understood, as can be seen in FIGS. 3 and 7, that this angular displacement of the lock allows the release of the insert 6, and the release thereof relative to the frame 2 (according to arrow F).

As best seen in FIG. 3, each lock 10 comprises a body 12 which is provided, at a first end, with a foot 14 and, at a second end, opposite the first, with a head 16.

The head 16 has a straight slot 18 which allows the lock 10 to be actuated in rotation by a tool, not shown, for example a screwdriver.

The body 12 of the latch 10 comprises, at the end opposite to the foot 14, a cylindrical base 15 which is formed under the head 16, and which is partly embedded in the frame 2.

Each lock 10 is therefore in the form of an essentially cylindrical metal part, of generally elongated shape.

The body 12 of the latch 10 is provided with one or more so-called retaining shoulders 20a, 20b which extend transversely relative to the body 12, and which are retained axially (FIGS. 1, 3 and 5) by one or more regions deformed material constituting the frame 2, when the latch 10 is in place therein. As seen in fact in Figures 1, 3 and 5, the material of the body or frame 2 covers the shoulder (s) 20a, 20b; the body of the lock 10 being embedded in the form of an insert in this material. In addition, in the two embodiments of FIGS. 1 to 5, the body 12 of each latch 10 has, along its length, at least one collar 22 which is permanently anchored, that is to say permanently, in the material forming the frame 2, this collar thus participating in the holding of the lock 10 in the frame.

Indeed, in these two embodiments the latch 10 is provided with two retaining shoulders 20a, 20b; the first shoulder 20a being formed on the foot 14 and in particular on its side facing the head 16, this foot 14 being also chamfered at its free end to allow the introduction of the latch 10 in the material of the frame, and in particular in a pilot hole 24 (FIG. 1) formed therein. The second retaining shoulder 20b is in turn formed on the collar 22, also on the side of the head 16.

As seen in Figure 7, the collar 22 of the third embodiment is chamfered on a first side 22a, oriented towards the foot 14, while it has a flat transverse shoulder referenced 20c on its second side 22b which is opposite at the first 22a and which is oriented towards the head 16. This arrangement makes it possible to insert the latch 10 in the frame 2 by cold deformation.

It will be specified here that, preferably, in the embodiments which have just been described, each collar 22 is of circular shape and extends continuously around the body 12 of the latch 10. In an alternative embodiment not shown, this collar 22 can be formed by one or more corner segments partially covering the body 12.

As can be seen in FIGS. 1, 3, 5 and 7, the collar 22 is formed on the body 12 of the latch 10, at a distance from the foot 14.

In the embodiments shown, this collar 22 is formed approximately in the middle of the body 12, namely in a median region thereof.

It will be noted (FIG. 3) that the base 15 has an outside diameter D3 which is greater than that, referenced D2, of the collar 22; this same diameter D2 of the collar 22 being greater than the outside diameter D1 of the foot 14.

Thus the latch 10 has a stepped profile, the outer envelope of this latch varying progressively from the foot 14 towards the head 16.

As will be understood below, the arrangement of the retaining shoulders 20a, 20b improves the resistance characteristics of the latch 10 when it is fixedly anchored in the material of the frame 2, which has been deformed, in these embodiments, hot and creep during the installation of this lock.

It will further be noted that the latch 10 comprises, in the embodiments of FIGS. 1 to 5, two other shoulders 21a, 21b formed respectively under the collar 22 and under the base 15. These shoulders are oriented towards the foot 14, and they ensure the discharge of the synthetic material from the frame, under the effort of introducing the lock therein.

In the first embodiment, and as seen in FIG. 3, the shoulders 20a and 21a are formed by the two faces of a radial groove 26a shaped in the body of said latch, between the foot 14 and the collar 22. The latch 10 further comprises a second radial groove 26b, formed between the collar 22 and the base 15 and forming the shoulders 20b and 21b.

It will therefore be noted that the geometry of the latch 10 which has just been described must be such that the material which has been deformed by creep by the shoulders 21a, 21b has sufficient space to come to be housed in the grooves 26a and 26b and to come fill them. Thus, the grooves or recesses 26a and 26b must define at least a volume equal to that of the material pushed back by the shoulders 21a and 21b.

As can be seen in FIGS. 1 to 5, the head 16 of the latch 10 has radial wings 28, here four in number, which are angularly displaceable by a corresponding action of the tool, not shown, in the slot 18. These wings 28 are shaped to cover, in a so-called locking position, one or more support regions 30, in particular of partially frustoconical shape or in the form of cylindrical recess (not shown), formed directly on the insert 6 in order to maintain it on the frame 2.

Although four wings 28 have been shown here on the head 16, it should be noted that the latter may have another construction having one or another number of wings 28.

As can be seen in FIGS. 2 and 4, each bearing region 30 is formed by the deformation of an edge, not referenced, of a passage orifice 32 formed in the insert 6. This deformation can be achieved by cold deformation of the material, for example by stamping.

Referring to Figures 5 and 6, we see that according to another embodiment the latch 10 has lateral flats 32a, 32b formed on either side of the base 15 and extending longitudinally relative to the body 12 These flats 32a, 32b (two in this example) form (FIG. 6), when the lock is put in place, corresponding flat shapes in the material of the frame 2. These flats keep the lock 10 in its angular position. locking, and during the rotation thereof, by a tool, they constitute means for increasing the torque in the material. These flats are formed by machining a particular side of the lateral straight sides of the head 16 and the slot 18, by a single operation, using a milling cutter train. Although two flats have been shown here, it is understood that in a variant not shown, only one can be provided on the latch 10.

As stated above, the invention further relates to a method of assembling the insert 6 on the frame 2. In this method, one or more pilot holes 24 are first cleaned in the frame 2, then the insert 6 is provided, which is provided with one or more through orifices 32.

After the insert 6 has been placed on the frame 2, one or more fixing locks 10, such as the one just described, are provided.

Then, each lock 10, preferably oriented in its locking position (FIGS. 1, 2, 5 and 6) is introduced into a pilot hole 24 made in the frame 2, via the passage orifice 32 of the insert 6, while deforming the material constituting the frame 2, under the action of the discharge shoulders 21a, 21b, to cause this repressed material to cover the shoulder (s) 20a, 20b. This introduction of the bolt (s) 10 into the material of the frame 2 is continued until the blocking flange (s) 28 of each bolt 10 come into contact with the bearing regions 30 to rest on the insert 6.

It will be specified here that in the embodiments of FIGS. 1 to 6, the material of the frame 2 is deformed by heating it which is provided by the lock itself, during its installation.

This heating of the material is caused for example by the application of high frequency vibrations to the latch 10 at the same time as it is pushed into its pilot hole 24. These frequencies are preferably chosen from the range of ultrasound.

In the embodiment of FIG. 7, the latch 10 is put in place by a cold deformation of the material of the frame 2.

It is therefore understood that each lock 10 is placed on the timepiece 1 preferably in an angular position such that the wings 28 come to cover the support region 30. In other words, the lock (s) 10 are placed on the timepiece in their angular locking position to abut on the insert 6 and also to define their proper operating height relative to this part.

Thus, when it is put in place, each latch 10 automatically cleans, during its own introduction, straight recesses or grooves in the material forming the frame 2. These grooves or recesses, not referenced, ensure the axial maintenance of the lock 10 but allow its rotation to release the wings 28 from the support regions 30 and to allow the release of the protection plate 6 when the wings 28 in the rotated position (FIGS. 3 and 4) coincide with the clearance formed by the orifice 32.

The head 16 of the lock 10 remains at constant height, whether this lock is in its locked position or in its unlocked position. Thus, when the end of a tool, not shown, such as a screwdriver, is introduced into the slot 18 of the head 16 which remains embedded in the insert plate 6, this tool end is held laterally by the flange of the passage orifice 32 of the added plate 6, and cannot slide to possibly injure one of the constituents of the timepiece 1, in particular the coil in this case.

In addition, the rotation of the lock 10 does not cause, during the disassembly / reassembly operations, any axial displacement of the latter, there is no risk of the synthetic material being torn from the frame, which improves the service life. of this arrangement. Furthermore, during these operations, the thrust of the screwdriver towards the frame does not cause the latches to move axially in depth, the latter being stabilized downwards by the discharge shoulders 21a, 21b.

The locks 10 being fixed permanently, that is to say permanently, in the frame 2, there is no risk of loss of these during these disassembly / reassembly operations.

Finally, these latches 10 allow the arrangement of this arrangement in frames having thin walls.

Claims (15)

Timepiece of the type comprising a body or frame (2) on which an attached piece (6) is detachably held, such as for example a protective plate, this piece being held on the body or frame (2 ) by fixing means integral with the body or frame that can rotate while remaining at a constant height relative to the body or frame to allow release of said insert (6) and the release thereof, characterized in that the fixing means are constituted by at least one lock (10) which is anchored in the material of the body or frame, with an axial immobilization with respect thereto. Timepiece according to claim 1, characterized in that the lock (10) comprises a body (12) provided with at least one shoulder (20a, 20b, 20c) which is retained axially by a deformed part of the constituent material said frame (2). Timepiece according to claim 2, characterized in that the body (12) of the latch (10) has, along its length, at least one collar (22) which comprises said shoulder (20b, 20c) and which is permanently anchored in the material forming said frame (2), this collar (22) improving the holding of the latch (10) therein. Timepiece according to claim 3, characterized in that said collar (22) is chamfered on a first side oriented towards a foot (14) of said latch (10) while it has a straight shoulder (20c) on a second side, opposite the first. Timepiece according to claim 3, characterized in that said collar (22) is formed at a distance relative to a foot (14) of said latch (10). Timepiece according to claim 5, characterized in that said collar (22) has an outside diameter (D2) greater than that (D1) of the foot (14). Timepiece according to claim 2, characterized in that said shoulder (20a) is formed by one face of a radial groove (26) formed in the body (12) of the latch (10). Timepiece according to any one of the preceding claims, characterized in that said lock (10) has a head (16) having at least one wing (28) angularly movable and shaped to cover in a position, called locking, a support region (30) formed on the insert (6) in order to ensure its maintenance on the body or frame (2). Timepiece according to claim 8, characterized in that said bearing region (30) is formed by deformation of an edge of a passage orifice (32) formed on the insert (6). Timepiece according to any one of the preceding claims, characterized in that the lock (10) comprises at least one lateral flat (32a, 32b) extending longitudinally relative to it and constituting in the material of the body or frame (2) a corresponding flat shape to increase the torque of the latch (10) in said body or frame (2). Method of assembling an insert on a body or frame of a timepiece, characterized in that it consists: - to provide a pilot hole (24) on said body or frame (2), - Providing at least one fixing lock (10) intended to hold an added piece (6) on the body or frame (2), this lock (10) having at least one shoulder (20a, 20b, 20c) and at least a locking wing (28), and - Introducing said lock (10) into the pilot hole (24) of the frame while deforming the material constituting said body or frame (2) to cause it to cover said shoulder (20a, 20c, 20b), in order to hold said latch (10) in place by the very material of the body or frame (2), this lock in this position being able to maintain said insert. Assembly method according to Claim 11, characterized in that the said lock (10) is introduced into the body or frame (2) by orienting the said locking wing (28) in an angular position such that it comes to rest on the insert (6) previously positioned on the body or built to lock it. Assembly method according to claim 11, characterized in that the material of the body or frame (2) is deformed by heating it provided by the latch (10) during its installation. Assembly method according to claim 13, characterized in that the material is heated by the application of high frequency vibrations to the latch (10). Assembly method according to claim 14, characterized in that the high frequencies are chosen from the range of ultrasound.

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