System for attaching display element and measuring instrument

Abstract

The utility model relates to a system for attaching a display element and a measuring instrument. One aspect of the utility model relates to a system (1) used for attaching a display element (2) to a driving shaft (3), the driving shaft is assembled to a simulation display mechanism of a measuring device, the system (1) comprises an installation part (6) used for installing the display element (2) and an embeddable end piece (4a) of the driving shaft (3), the installation part is made of materials with softening characteristics, and the installation part is made of materials with softening characteristics. And an embeddable end piece (4a) configured to be bonded by fusion into the mounting portion (6), the end piece (4a) comprising a portion of an outer peripheral wall (13) of the drive shaft (3) provided with a patterned outer bonding surface configured to mechanically anchor the end piece (4a) in the mounting portion (6).

Description

Technical Field

[0001] The present utility model relates to the field of measuring instruments, particularly to the field of watchmaking, and more particularly to the field of systems for attaching a display element, such as a display hand, to the drive shaft of a display mechanism.

[0002] The present utility model also relates to a measuring instrument, such as a timepiece, including such a display element mounted on the drive shaft using this attachment system. Background Art

[0003] In the prior art, a measuring instrument, such as a timepiece, includes a hand that is attached to its drive shaft by means of a forced drive attachment system, which is a hollow cylinder, in this case a tube, that is forced onto a mandrel whose diameter is slightly larger than the inner diameter of the cylinder. In this system, the elastic and plastic properties of the material used are employed for this driving operation, and the material is typically metal. As a result, the hollow cylinder can only be driven onto a conventional rotating shaft, such as those used in mechanical watchmaking, with a diameter difference of a few micrometers. Alternatively, the hollow cylinder is preferably a straight circular cylinder, and the hollow cylinder can also be driven onto a frustoconical rotating shaft in order to limit the excessive driving force that may damage the movement during this operation.

[0004] In addition, the attachment of the hand must provide sufficient force to hold the hand in place during impacts. For example, the force required for driving in a conventional watch hand is on the order of 30 N.

[0005] To solve these problems, one solution is to manufacture a hand with a tube that has one or more slots parallel to the axis of rotation and that open at opposite ends of the hand such that the tube elastically deforms.

[0006] However, a major drawback of this solution is that the slots in the tube weaken the tube, which means that the slots must be very narrow so as not to weaken the tube too much. It should also be noted that in order to obtain as fine slots as possible while considering the width and length required to obtain the desired driving force, the machining operation is complex, which increases the production cost and time. Summary of the Utility Model

[0007] The main object of the present utility model is to overcome the various drawbacks of the prior art.

[0008] Another object of the present utility model is to provide an attachment system that improves the retention of a display element with a non-metallic body on the drive shaft of a display mechanism of a measuring instrument and is thus insensitive to magnetic fields.

[0009] Another object of the present utility model is to provide an attachment system in which the display element has a reduced mass and inertia and can be of any desired shape.

[0010] Another object of the present invention is to provide an attachment system in which the display element is robust over time and the manufacturing cost thereof is reduced.

[0011] According to the present invention, one aspect of the present invention relates to a system for attaching a display element to a drive shaft, the drive shaft being assembled to an analog display mechanism of a measuring instrument, the system comprising a portion for mounting a display element made of a material having softening characteristics and an insertable end member of the drive shaft, the insertable end member being configured to be joined to the portion by fusion, the end member including a portion of the outer peripheral wall of the drive shaft, the portion being provided with a patterned outer bonding surface configured to mechanically anchor the end member in the portion.

[0012] In other embodiments:

[0013] - The mounting portion includes a tube in which a shaft hole is formed, and the shaft hole is configured to mount the display element to the drive shaft;

[0014] - The insertable end member is joined to the tube by fusion;

[0015] - The patterned outer surface includes a plurality of raised patterns;

[0016] - The plurality of raised patterns extend over all or part of the patterned outer surface;

[0017] - A portion of the outer peripheral wall of the end member protrudes respectively on both sides of the opposite faces of the mounting portion of the display element;

[0018] - The material that is easily softened wholly or partly includes a plastic material having softening characteristics;

[0019] - The end member includes a first and a second portion protruding respectively from two opposite openings of the shaft hole of the tube;

[0020] - The insertable end member is made of a material having a softening point higher than that of the material constituting the mounting portion;

[0021] - A region for assembling the mounting portion and the end member, wherein the materials respectively constituting the end member and the tube are joined to each other by fusion, integration or association, in particular by fusion, integration or association using ultrasound;

[0022] - The display element has a body that is symmetric with respect to a longitudinal symmetry plane and / or a transverse symmetry plane;

[0023] - The display element is a display pointer, the body of which includes a board provided with the assembly area.

[0024] Another aspect of the present invention relates to a measuring instrument including at least one such display element mounted on an embeddable end piece of a drive shaft using such an attachment system.

[0025] Advantageously, such an instrument is a timepiece. Description of the Drawings

[0026] Other features and advantages of the present invention will be better understood by reading the following description given by non - limiting specific embodiments of the present invention, which description is provided for descriptive purposes with reference to the accompanying drawings, in which:

[0027] Figure 1 is a view of a system for attaching a display element for mounting the element on an embeddable end piece of a drive shaft of a display mechanism of a measuring instrument according to an embodiment of the present invention;

[0028] Figure 2 is a top view of the attachment system according to an embodiment of the present invention, in which the end piece of the shaft is incorporated into or integrated with or combined with the tube of the display element; and

[0029] Figure 3 is according to an embodiment of the present invention Figure 2 longitudinal sectional view along line III - III of the mounting portion of the display element shown. Detailed Description

[0030] Referring Figures 1 to 3 , the present invention relates to a system 1 for attaching a display element 2 to a drive shaft 3 of an analog display mechanism of a mechanical, electronic or hybrid measuring instrument. The device can contribute to measuring the movement speed of an object by acting as a tachometer, measuring atmospheric pressure by acting as a barometer or even measuring time by acting as a timepiece such as a watch, in a non - limiting and non - exhaustive manner. It should be noted that such a measuring instrument can be a portable object.

[0031] Referring Figure 1 , the system 1 includes a display element 2 and in particular the mounting portion 6 of the display element 2 and a drive shaft 3 and in particular the end piece 4a of the shaft 3. In the system 1, the end piece 4a and the mounting portion 6 are configured to cooperate with each other in order to attach the display element 2 to the drive shaft 3. More specifically, the mounting portion 6 includes a tube 14 in which a shaft hole 5 is provided, the hole being configured to mount the display element 2 on the drive shaft 3. In other words, the tube 14 and the end piece 4a are configured to cooperate with each other to attach the display element 2 to the drive shaft 3.

[0032] This display element 2 is also referred to as a "display indicator". The display element includes a body 8 provided with a mounting portion 6, which mounting portion includes an assembly area 7, which assembly area includes a tube 14 in or with which the drive shaft 3 of the drive member of the display mechanism can be joined, integrated or combined. It should be noted that the present utility model can be applied to analog display mechanisms for mechanical, electronic or hybrid timepieces.

[0033] In an embodiment of the attachment system 1, the display element 2 is preferably a display pointer. However, it can be clearly understood that the display element 2 is obviously not limited to a pointer, and it can be completely different from a pointer and, for example, can be a disk. It should also be noted that the display element 2 is described here as a particular but non-limiting case of a rotating element, such as a rotating pointer. However, in principle, the present utility model can also be applied to a display element 2 having a non-circular movement trajectory, such as a linear cursor, etc.

[0034] It should also be noted that when the measuring instrument is a timepiece, the pointer can be included in the display mechanism as an hour hand, minute hand or second hand having a variable length or variable radial extension.

[0035] Reference Figure 1 , the display pointer (display element 2) includes a body 8 formed by a plate, which plate includes a first end provided with a counterweight 9 and an opposite second end, which second end includes a tip 10 indicating information, such as the time when the display mechanism is a timepiece display mechanism. In this plate, such a tip 10 adopts a triangular shape in this case, but can have any other suitable shape in order to indicate a specific angular position on the dial of the timepiece. The counterweight 9 is preferably rectangular in shape. However, the counterweight can adopt any other shape, for example, the counterweight 9 can adopt the shape of an identification.

[0036] In this pointer, the plate also has a head located between the counterweight 9 and the tip 10 of the pointer. This head includes a mounting portion 6 in which the drive shaft 3 can be joined or integrated, especially in the tube 14 of the assembly area 7 of this mounting portion 6. Such an assembly area 7 and thus the tube 14 include a shaft hole 5, which is also referred to as an "adjustment diameter", which is provided for joining the embeddable end piece 4a of the drive shaft 3. It should be noted that the shaft hole 5 has a surface area that is substantially smaller than the cross-section of the embeddable end piece 4a. The term "substantially smaller" is understood to mean "strictly smaller" or "substantially smaller". The shaft hole 5 has two opposite openings 15a, 15b visible in Figure 1

[0037] In the present text, the plate is made in whole or in part of a material having softening properties, such as a plastic material, in particular a thermoplastic material. Preferably, such a material is a rigid material having softening properties. In these cases, the material can be heated sufficiently to soften and become rigid / hard again upon cooling. Such a plastic material consists of a straight-chain or branched-chain polymer that is capable of deforming and shaping under the action of heat. The plastic material includes, for example, thermoplastic polymers.

[0038] Thus, it can be understood that the plate can be made entirely or solely of such a material having such softening properties. Alternatively, such a plate can be made in part of such a material, where at least the mounting part 6 and thus the tube 14 are made of such a material.

[0039] In the system 1, the drive shaft 3 including the axis of rotation A1 is also referred to as the "rotating shaft" or the "drive shaft". Such a shaft 3 includes an insertable end piece 4a that is configured to be incorporated into, integrated into, or combined with the tube 14 in the assembly area 7 of the mounting part 6 of the pointer's plate. It should be noted that the end piece 4a is particularly configured to be attached or anchored in the assembly area 7.

[0040] In Figure 1 and Figure 3 the drive shaft 3 includes: a main part 4b that is connected to the drive member of the display mechanism; and the free end of the shaft 3 that forms the insertable end piece 4a (also referred to as the "pivot"). Such an end piece 4a is preferably formed integrally as a single piece with the main part 4b of the shaft. Alternatively, the end piece 4a can be a part that is fastened to the main part 4b by being assembled to the part 4b in a non-limiting and non-exhaustive manner, such as by driving, bonding, or welding.

[0041] The shape of such an insertable end piece 4a is substantially cylindrical. Of course, it can be understood that the insertable end piece can have other shapes. Such an insertable end piece 4a is preferably made of a material having a softening point that is higher than the softening point of the material constituting the mounting part 6 and thus also higher than the softening point of the material of the tube 14 on which the insertable end piece may be incorporated, integrated, or combined. Such a material is preferably a metal, such as aluminum, brass, steel, or titanium. Alternatively, the material can also be a thermosetting material. It should be noted that the main part 4b of the shaft is preferably also made of the same material as the end piece 4a. Alternatively, the main part 4b can be made of a material different from the material of the end piece 4a, although such a material must have a softening point that is substantially similar to the softening point of the material of the insertable end piece 4a.

[0042] Furthermore, in Figures 1 to 3In this case, the end piece 4a includes a portion of the outer peripheral wall 13 of the shaft 3, and this portion is provided with an outer surface for engaging with the tube 14 of the mounting portion 6 of the plate, in particular a patterned outer engaging surface. Such a patterned outer surface includes a plurality of raised patterns 12. The plurality of patterns 12 preferably extend over the entire outer surface of this portion of the outer peripheral wall 13. Alternatively, the plurality of patterns 12 may be distributed over a specific area of the outer surface, and this area is configured to cooperate with the material of the tube of the mounting portion 6 of the plate constituting the pointer. It should be noted that these patterns 12 may be the same, that is, have a similar three-dimensional shape, as Figure 2 visible in. It should be noted that this three-dimensional shape is specifically configured to ensure that the end piece 4a is firmly mechanically anchored in the tube 14 of the assembly area 7 of the mounting portion 6.

[0043] Such a patterned outer surface helps to increase the contact surface between the end piece 4a and the material used in the tube of the mounting portion 6 of the plate. In addition, in this configuration, the material can be inserted onto and between the raised patterns 12 on the surface to ensure that the plate is firmly held on the end piece 4a. Therefore, it can be understood that the retention of the end piece 4a in the tube 14 of the mounting portion 6 is thus improved, and thus helps to ensure the optimal mechanical anchoring of the end piece in the tube 14.

[0044] As already mentioned, the end piece 4a of the shaft 3 is embedded in the tube 14 of the mounting portion 6 of the plate by integration / combination or fusion. More specifically, as a result of the operation of fusing / integrating / combining the materials respectively constituting the end piece 4a of the shaft 3 and the tube 14 of the mounting portion 6, the end piece 4a is embedded in the tube 14 of the mounting portion 6. This operation softens the material constituting the mounting portion 6 including the tube 14 by supplying energy to ensure that the end piece 4a is inserted and anchored in the mounting portion 6, and in particular is inserted and anchored in the tube 14 of the assembly area 7. Therefore, in the assembly area 7 of the mounting portion 6 having the end piece 4a, the materials respectively constituting the end piece 4a and the mounting portion 6 including the tube 14 are joined to each other by fusion, integration or combination due to this energy supply. It should be noted that the energy can be supplied in a non-limiting and non-exhaustive manner by ultrasound or by a heating element, by laser or by steam injection.

[0045] In the case of using ultrasound, such an operation can be an ultrasonic fusion / integration / combination operation. This operation softens the material constituting the mounting portion 6 including the tube 14 by applying mechanical vibrations to the mounting portion 6, and the mechanical vibrations are generated by ultrasound. Herein, these mechanical vibrations then generate frictional heat in the mounting portion 6 of the material having softening characteristics and excite its molecules, and the molecules then will start to move. Accordingly, the material of the mounting portion 6 including the tube 14 becomes more flexible when softened, thereby allowing the end piece 4a to be inserted / embedded into the mounting portion 6 and bonded to the material. In particular, the end piece 4a is then embedded into the axial hole 5 of the assembly area 7. Herein, the assembly area 7 holds the end piece 4a in the tube 14 of the mounting portion 6 and thus helps to axially and rotatably hold the pointer on the drive shaft 3.

[0046] In this configuration, in the case where the end piece 4a is arranged in the plate of the pointer, it should be noted that the outer peripheral wall 13 including the end piece 4a projects on both sides of the opposite faces of the mounting portion 6 of the plate showing the pointer. These two opposite faces are connected together by the side wall of the pointer. Such an arrangement of the end piece 4a in the mounting portion 6 helps to axially and rotatably stabilize the display pointer.

[0047] More specifically, the end piece 4a includes first and second portions 16a, 16b which project from two opposite openings 15a, 15b of the axial hole 5 of the tube 14 respectively. These first and second portions 16a, 16b define the surface of the end piece 4a on the outer peripheral wall 13 of the drive shaft 3. In this configuration, these first and second portions 16a, 16b of the end piece 4a have preferably similar thicknesses E3, E4. Such thicknesses E3, E4 are less than the following thicknesses:

[0048] - the thickness E1 of the end piece 4a;

[0049] - the thickness E2 of the tube 14.

[0050] Such an arrangement of the end piece 4a in the tube 14 helps to axially and rotatably stabilize the display pointer 1. In addition, such an arrangement helps to make the stress distribution uniform when the pointer is assembled to the drive shaft and after it is assembled to the shaft. In other words, such stress is uniformly distributed over the entire thickness E2 of the main body 8. Such uniform distribution ensures that the main body 8 of the pointer and the mounting portion 6 including the tube 14 remain flat. Accordingly, the main body 8 of the pointer remains flat after being assembled to the shaft 3.

[0051] It should be understood that such an arrangement of the end piece 4a in the main body 8 of the pointer allows the use of a wider range of materials, especially by making it less necessary to use particularly reinforced materials to prevent deformation of the pointer that may be caused by such stress.

[0052] It should also be noted that the display pointer is symmetric with respect to the longitudinal symmetry plane P1 and / or the transverse symmetry plane P2 of the pointer. It should be understood that these two planes P1 and P2 are perpendicular to each other. Due to the symmetry, this display pointer is flip - able, which helps to simplify and reduce the time spent assembling it in the display mechanism. In other words, this display pointer can be assembled on the shaft 3, and its visible face can be either of its two opposite faces.

[0053] The above description corresponds to the preferred embodiment and should not be considered restrictive in any case, and more specifically so with regard to the type of display element 2 used in the system 1. More specifically, other display elements such as disks, especially date disks, are also part of the present utility model.

[0054] Furthermore, this description is also not limited to the forms described for the various structural elements or their materials that make up the display element 2. A person skilled in the art will have no particular difficulty in selecting any other material, for example, for the plate of the pointer, that has the mechanical properties necessary to implement the present utility model.

[0055] Since the present utility model can be implemented in any type of object or device, especially in a portable object or device including the display element 2, the possible applications of this system 1 for attaching the display element 2 are very numerous.

[0056] Reference numerals

[0057] 1 System for attaching a display element

[0058] 2 Display element

[0059] 3 Drive shaft

[0060] 4a Embeddable end piece of the drive shaft

[0061] 4b Main part of the drive shaft

[0062] 5 Shaft hole of the display element

[0063] 6 Mounting part of the display element

[0064] 7 Assembly area of the display element

[0065] 8 Body of the display element or plate of the pointer

[0066] 9 Counterweight of the plate

[0067] 10 Tip of the plate

[0068] 12 Multiple patterns

[0069] 13 Outer peripheral wall of the drive shaft

[0070] 14 Tube of the display element

[0071] 15a, First and second openings of the shaft holes of 15b

[0072] 16a, 16b First and second parts protruding from the shaft holes

[0073] A1 Axis of rotation of the drive shaft

[0074] P1 Longitudinal symmetry plane P1 of the display element / pointer

[0075] P2 Transverse symmetry plane P2 of the display element / pointer

Claims

1. A system (1) for attaching a display element (2), said system attaching said display element (2) to a drive shaft (3) which is fitted to an analog display mechanism of a measuring instrument, characterized in that The system (1) comprises a mounting portion (6) made of a material having softening properties for mounting the display element (2) and an embeddable end piece (4a) of the drive shaft (3) configured to be bonded into the mounting portion (6) by fusion, the end piece (4a) comprising a portion of an outer peripheral wall (13) of the drive shaft (3), the portion being provided with a patterned outer bonding surface, the patterned outer bonding surface being configured to mechanically anchor the end piece (4a) in the mounting portion (6).

2. The system (1) according to claim 1, wherein: The mounting portion (6) includes a tube (14) in which a shaft hole (5) is formed and configured to mount the display element (2) to the drive shaft (3).

3. The system (1) according to claim 2, wherein: The embeddable end piece (4a) can be configured to be incorporated into the tube (14) by fusion.

4. The system (1) according to any one of claims 1 to 3, wherein: The patterned outer bonding surface includes a plurality of raised patterns (12).

5. The system (1) according to claim 4, wherein: The plurality of raised patterns (12) extend over all or part of the patterned outer bonding surface.

6. The system (1) according to any one of claims 1 to 3, wherein: The portion of the peripheral wall (13) of the end piece (4a) protrudes on both sides of the opposite faces of the mounting portion (6) of the display element (2).

7. The system (1) according to any one of claims 2 to 3, wherein: The end piece (4a) includes a first portion and a second portion (16a, 16b) protruding from two opposite openings (15a, 15b) of the axial hole (5) of the tube (14), respectively.

8. The system (1) according to any one of claims 1 to 3, wherein: The easily softenable material comprises in whole or in part a plastic material having softening properties.

9. The system (1) according to any one of claims 1 to 3, wherein: The embeddable end piece (4a) is made of a material having a softening point higher than the softening point of the material constituting the mounting portion (6).

10. The system (1) according to any one of claims 2 to 3, wherein: The system comprises an assembly area (7) for assembling the mounting portion (6) with the end piece (4a), wherein the materials constituting the end piece (4a) and the tube (14), respectively, can be configured to be bonded to each other by fusion, integration or combination.

11. The system (1) according to claim 10, wherein: The materials constituting the end piece (4a) and the tube (14), respectively, can be configured to be bonded to each other by fusion, integration or combination using ultrasound.

12. The system (1) according to any one of claims 1 to 3, wherein: The display element (2) has a body (8) that is symmetrical with respect to a longitudinal symmetry plane (P1) and / or a transverse symmetry plane (P2).

13. The system (1) according to claim 10, wherein: The display element (2) is a display pointer, the body (8) of which comprises a plate provided with the assembly area (7).

14. A measuring instrument, characterized in that: The measuring instrument comprises at least one display element (2) mounted on an embeddable end piece (4a) of a drive shaft (3) using a system (1) according to any one of claims 1 to 13.

15. The measuring instrument according to claim 14, wherein: The measuring instrument is a timepiece.

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