Watch case with bayonet connection and lock

Abstract

The invention relates to a watch case (1) comprising a case (3) adapted to receive a movement (8) and a battery (9) housed in a compartment of the movement (8), a case back (2) assembled with a bayonet connection in the case (3) and a lock (6) disposed at the bayonet connection to block any relative rotation between the case back (2) and the case (3).

Description

Technical field of the invention

[0001] The invention relates to a watch case adapted for an electronic watch. More specifically, it relates to a watch case comprising a case middle and a back assembled with a bayonet joint equipped with a lock to secure access to the battery. Technological background

[0002] Portable electronic devices can be powered by one or more removable power sources, such as batteries, accumulators, or cells.

[0003] For example, electronic or electromechanical watches are powered, at least partially in the case of electromechanical watches, by a removable electrical power source, such as a button cell battery, which is housed in a compartment within the watch case. A removable cover is provided to enclose the battery within the compartment, ensuring at least some water resistance. Typically, the battery is housed in a battery well covered by a lid on the bottom of the watch case.

[0004] To ensure easy battery replacement, the cover and casing typically feature quick-release, rotating coupling / uncoupling mechanisms that allow rapid access to the battery and quick closure of the compartment after battery replacement. Examples of such quick-release coupling / uncoupling mechanisms include quarter-turn or bayonet-type assembly systems.

[0005] Furthermore, the cover may have an indentation on its outer surface designed to receive the end of a tool, allowing it to be rotated. To further facilitate battery replacement, this indentation is often a simple and common shape, such as a slot, so that the wearer can use various readily available tools to open the compartment without needing a specialized tool or taking the watch to a watchmaker for battery replacement.

[0006] However, these various interesting and advantageous technical solutions for battery replacement can also present drawbacks in certain situations, particularly when handled by children, and especially young children. Indeed, these young children could inadvertently manage to remove the battery cover and access the battery compartment, creating a risk of ingestion, with the serious consequences that this can entail.

[0007] Therefore, there is a need to secure watch cases to prevent access to the battery compartment by an irresponsible person, and particularly young children, while retaining the advantages of easy and quick removal of the cover. Summary of the invention

[0008] The present invention proposes a watch case design that allows secure access to a rechargeable battery or cell.

[0009] According to the invention, the watch case is formed by joining the case back and the case middle with a bayonet fitting. The entire assembly is secured by a lock that prevents the case back from rotating relative to the case middle.

[0010] More specifically, the invention relates to a watch case comprising a case adapted to receive a movement and a battery housed in a compartment of the movement, a case back assembled with a bayonet connection in the case and a lock disposed at the bayonet connection to block any relative rotation between the case back and the case.

[0011] This design allows the electrical power source to be placed inside the watch case with locking mechanisms that prevent access to the power source without a specific tool. This makes it possible to assemble and disassemble a watch case while securing access to the battery. The case back itself forms the battery cover. Unlike a battery well with a cover, this design allows for the easy installation of a lock. Brief description of the figures

[0012] There Figure 1A represents an exploded view of the watch case according to the invention. figure 1B represents a three-dimensional view of the bottom. The figure 2 represents a three-dimensional view of the watch case according to the invention. figure 3 represents a partial vertical cross-sectional view of the bayonet fitting. figure 4 represents a three-dimensional view of the lock according to one variant. figure 5represents a horizontal cross-sectional view of the watch case with this lock variant. figure 6 This represents a partial vertical cross-sectional view of this lock variant within the watch case, showing the positioning of the tool for removing the lock. figure 7 represents a horizontal cross-sectional view of the watch case fitted with the lock according to another variant, with an enlargement of the lock at the bayonet connection. Detailed description of the invention

[0013] The invention relates to a watch case 1 more specifically adapted for an electronic watch. Conventionally, it comprises a back 2, a case middle 3 and a crystal 4 visible at Figure 1A and 2The case back 2 has a slot 18 or holes (not shown) on its accessible face for receiving a tool to detach the case back from the case. The case 3 and the crystal 4 can be a single unit, with the crystal welded to the case to form a container. The watch case also includes a sealing gasket 5 between the case 3 and the case back 2, visible in the figure 3 .

[0014] According to the invention, the case back 2 and the case middle 3 are assembled with a bayonet joint equipped with a locking mechanism 6 that prevents the case back from rotating relative to the case middle after assembly. This locking mechanism 6 can be an added component on the case middle 3 and the case back 2, as shown in the figures. Figures 1A And 5 à 6 or be an integral part of fund 2 as shown in the figure 7 Preferably, the lock 6 is positioned between the lugs 7 of the case 3 so as to be hidden after the bracelet is put on.

[0015] To ensure the bayonet connection, the base 2 has a groove 10 formed in a rim 11 extending in an arc around the perimeter 2a of the base 2 towards the case ( Figures 1A and 1B The groove 10 is open at least at one end of the arc to allow the engagement of a protruding rim 12 inside the case 3 and optionally closed at the other end by a stop (not shown). The figure 3 This represents a cross-sectional view of this bayonet joint with the rim 12 of the case 3 engaged in the groove 10 of the base 2. The rims 11 and 12 are preferentially present in number around the perimeter 2a of the base 2 and inside the case 3 respectively. In the illustrated example, there are two rims 11 and 12, diametrically opposed.

[0016] The 3-frame size visible at the Figure 1AIt includes a through-hole 3a for housing a movement 8 and a battery 9 housed in a compartment of the movement 8. The side wall of the housing 3a has the edges 12 of the bayonet fitting extending radially from the lower end of the side wall, i.e., from the end facing the bottom. A rim 15 is cut into this side wall, against which the gasket 5 and the bottom 2 bear.

[0017] To prevent the case back from rotating relative to the case, a locking bolt 6 is placed at the bayonet lug. In a first variant visible at figures 1A-1B-2 And 4-6The lock 6 is an added piece on the case 2 and on the base 3. For this purpose, the groove 10 of the base 2 communicates with a notch 13 made in the rim 11. The notch 13 is intended to be positioned opposite an opening 14 made in the wall of the case 3 to receive the lock 6 together. Said opening 14 passes through the wall of the case at the level of the rim 12, possibly in the middle of the rim 12.

[0018] The lock 6, according to the first variant, is a flexible piece with two hooks 6a, 6b at the lateral ends that hook the ends 11a, 11b of the rim 11 that frame the notch 13 in the bottom. As shown in the figure 4The lock 6 has three recesses 6c in the example to provide this flexibility to the part. The lock may also include a central tab 6d that separates two recesses 6c at the level of the two hooks 6a, 6b. To lock the bayonet joint against rotation, the lock is pinched to bring the two hooks 6a, 6b together and inserted simultaneously into the opening 14 in the case and the notch 13 in the base. The two hooks 6a, 6b then return to their position to hook the ends 11a, 11b of the rim. To remove the lock, it is necessary to insert a tool 15 into a slot 16 made through the base 2 ( Figure 1A ). As represented in the figure 6 , tool 15 presses on the tab 6d and on a wall 6e below the tab 6d, which will retract the hooks of the lock and push the latter out of the frame.

[0019] The locking mechanism 6, according to a second variant, is formed directly in the base 2. In place of the notch 13, the base 2 is provided with a flexible projecting portion 17 extending radially outwards from the base 2 at the level of one of the rims 11. The projecting portion 17 is made flexible by a recess 17a made within a part of the rim 11 and possibly within the projecting portion 17. The base therefore does not have a notch 13 intended to receive the locking mechanism, while the frame is provided with its opening 14 to receive the projecting portion 17. During assembly with the bayonet joint, the projecting portion is compressed against the lateral wall of the housing 3a of the frame before falling into the opening 14 of the frame and regaining its shape. To remove the lock, a tool (not shown) is inserted laterally into the opening 14 of the case to compress the protruding portion 17 and release the rotating base.

[0020] After removing the lock, the watch case can be disassembled by inserting a tool into slot 18 of the bottom 2 to impart a rotational movement to the bottom.

Claims

1. Watch case (1) comprising a case body (3) adapted to receive a movement (8) and a battery (9) housed in a compartment of the movement (8), a case back (2) assembled with a bayonet connection in the case body (3) and a lock (6) disposed at the bayonet connection to block any relative rotation between the case back (2) and the case body (3).

2. Watch case (1) according to the preceding claim, in which the case back (2) has on its periphery (2a) at least a first rim (11) through which a groove (10) passes and in which the case middle (3) has at least a second rim (12) projecting inside said case middle (3), said groove (10) being open at least at one end to allow the engagement of the second rim (12) when the case back (2) is rotated, and optionally closed at the other end by a stop to prevent rotation, the engagement of the second rim (12) in the groove (10) forming the bayonet connection.

3. Watch case (1) according to the preceding claim, in which the lock (6) is a flexible part attached to the case (3) and the bottom (2), an opening (14) being provided through the second rim (12) and the groove (10) communicating with a notch (13) made in the first rim (11), said notch (13) being positioned opposite the opening (14) to jointly receive the lock (6).

4. Watch case (1) according to the preceding claim, in which the lock (6) has two hooks (6a,6a) intended to hook respectively the ends (11a,11b) of the first rim (11) which frame the notch (13) of the bottom (2).

5. Watch case (1) according to claim 3 or 4, wherein the lock (6) has recesses (6c) to provide flexibility to said lock (6).

6. Watch case (1) according to any one of claims 3 to 5, wherein the bottom (2) is traversed by a first slot (16) to accommodate a first tool (15) in order to apply a force on said lock (6) ensuring its removal from the watch case (1).

7. Watch case (1) according to the preceding claim, in which the lock (6) has a tab (6d) disposed between the hooks (6a,6b) and a wall (6e) below said tab (6d) on which the force is applied.

8. Watch case (1) according to claim 2, wherein the lock (6) is an integral part of the case back (2) and is in the form of a flexible portion (17) projecting radially outwards from the case back (2), and in which an opening (14) is provided through the second rim (12), said flexible portion (17) being compressed against the case middle (3) during assembly with the bayonet connection before falling into the opening (14) of the case middle (3) and resuming its shape to ensure locking, unlocking being ensured by a second tool introduced into the opening (14) of the case middle (3) to compress the flexible portion (17).

9. Watch case (1) according to the preceding claim, wherein the flexible portion (17) is made flexible by a recess (17a) made within a part of the first rim (11) and optionally of the flexible portion (17).

10. Watch case (1) according to any one of the preceding claims, in which the lock (6) is positioned between lugs (7) of the case (3).

11. Watch case (1) according to any one of the preceding claims, wherein the case back (2) has on its visible face a second slot (18) or holes for the positioning of a third tool for mounting and dismounting the case back (2) ensuring its rotation relative to the case middle (3).

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