Gripping device for holding, centering and / or collet tightening of micromechanical or watch components

Abstract

To provide a gripping device for positioning and fastening a micromechanical or horological component, or a tool.SOLUTION: A gripping device 100 for holding, centering, and / or clamping a micromechanical or horological component 200 in a chamber delimited by a collet including at least one movable jaw and at least one stationary jaw 3, where some of the movable jaws and / or the stationary jaws 3 include a reference surface 20 for supporting the component 200 abutting from the front. The gripping device 100 includes both the stationary jaws 3 including the reference surface 20 for supporting the abutting component, and the movable jaws for centering and / or clamping the component 200.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a gripping device for holding, centering and / or collet clamping of a micromechanical or horological component in a clamping chamber delimited by a collet comprising at least one movable jaw.

[0002] The invention further relates to a method for mounting such a micromechanical or horological component in a clamping chamber contained in such a gripping device.

[0003] The invention relates to the field of micromechanics and to the positioning and clamping of components during a manufacturing step or the positioning and clamping of tools during a manufacturing step. [Background technology]

[0004] Extremely precise positioning of micromechanical components, especially watch components, in manufacturing tooling is always complicated. The requirement for such precise positioning must be balanced with sufficient clamping so as not to induce undesirable deformation. The problem is similar for positioning and holding microtools used in manufacturing operations, where perfect angular indexing is often required.

[0005] Existing fastening means include many variations of Jacobs chucks, whose collets are elastic or articulated to hold the component. In particular, in the watch industry, "Ottet" type collets are very commonly used in conventional fastening means. This type of fastener allows the component to be fastened by opening and closing several collet segments. The collet segments are typically elastically deformed under the combined action of a screw-nut system, an elastic return means such as a spring, a pressure piece such as a ball bearing said elastic return means, and an inwardly or outwardly tapering cone cooperating with a conical or rounded sector contained in said segment. These segments are usually intended to be machined internally to match as closely as possible the contour of the component to be fastened and can be machined in place in the machine for maximum precision. The collet itself is mounted on a pallet that is clamped / unclamped from an automatic fastening device that is typically fitted into a divider of a machining tool. The principle of cone fastening of such collets is described in US Pat. No. 5,399,363.

[0006] However, because these segments must pivot to clamp the component, there is no reference bearing point in space to ensure the height and position of the component. In other words, when a component is clamped with this type of collet, it becomes difficult to guarantee a precise axial and radial position. For example, if the components do not have exactly the same dimensions, or if the friction between the various segments and the clamping cone changes, the relative position of the component to the collet will change slightly. This problem is considerably greater for rework machining, which requires more localized machining operations than the previous operation.

[0007] When precision bearings are required, standard spring collets of this type are generally no longer used, since the space available in the center of the fastener is reserved for the mechanical components that transmit the clamping / unclamping forces.

[0008] As a result, customized solutions for these situations are typically required, which are therefore less flexible, have a larger overall size, and are more expensive.

[0009] Another issue relates to the ability to retain the machined component cut from the blank component, which will be the only piece remaining retained in the collet after the machining operation.

[0010] It is again noted that, taking into account the trend towards miniaturization of micromechanical machining tools, it is necessary to construct increasingly compact fastening means, which are able to guarantee all the desired functions as well as the necessary rigidity and precision. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] European Patent No. 1602426(B1) Summary of the Invention

[0012] The object of the invention is to improve the positioning and clamping of micromechanical or horological components or tools by incorporating precise reference bearing points. To this end, the invention relates to a gripping device for holding, centering and / or clamping a micromechanical or horological component according to claim 1.

[0013] The present invention thus overcomes the problem of providing a fixed reference bearing point in space by providing at least one fixed reference bearing point, in particular by modifying a standard commercially available collet of a recognized and popular model, which makes the manufacturing of the gripping device according to the present invention extremely cost-effective. Moreover, such modification does not alter the external dimensions of the collet.

[0014] Another aspect of the invention relates to a method for mounting such a micromechanical or horological component inside a clamping chamber contained in such a gripping device. [Brief description of the drawings]

[0015] The objects, advantages and features of the present invention will be better understood upon reading the following detailed description, given in conjunction with the accompanying drawings, in which:

[0016] [Figure 1] 1 shows a schematic representation of a gripping device according to the invention, which is manufactured on the basis of a commercially available spring collet that includes jaws separated by slots. Some of these jaws are machined internally in such a way that they can no longer move when the spring collet is activated, i.e. they are stationary jaws. These are contrasted with the movable jaws, which in a non-limiting alternative embodiment are arranged alternately. The spring collet is of the type that clamps substantially concentrically around the collet axis. [Diagram 2] FIG. 2 shows a schematic side view of the gripping device of FIG. 1; [Diagram 3] FIG. 2 shows a schematic top view of the gripping device of FIG. 1; [Figure 4]2 shows a schematic cross-section of the gripping device of FIG. 1 along the section plane AA in FIG. 2. The components are arranged in steps along the collet axis, starting from the lower end of the gripping device. The pallet comprises a standardized handling interface, in this case in the form of a groove, through which a housing of an operating member (not shown), such as a screw or rod for pushing or pulling, passes. The pallet bears a pushing member, in this case a ball arranged on a spring (not shown). The pushing member is actuated by an operating member to push an inwardly tapering cone, in this case a conical sector, which is included in a number of mobile jaws. These mobile jaws comprise a gap surrounding a holding plate that holds a stationary jaw, not shown in this cross-section. This plate bears the component to be positioned and clamped. This gap allows the movable jaw to be operated by pivoting it to clamp the component. It is understood that the movable jaw is thus actuated by an actuating cone when the clamping screw is moved. [Diagram 5] A feature of Figure 4 is shown illustrating this gap. [Figure 6] 3 shows a schematic cross-sectional view of the gripping device of FIG. 1 along the section plane BB in FIG. 2. It shows that the stationary and mobile jaws alternate. Only the conical sector of the mobile jaw is visible in the middle, the stationary jaw does not have an actuating cone. [Figure 7] The gripping device of FIG. 1 is shown similarly to FIG. 3 after pivoting of the jaws is complete. [Figure 8] The gripping device of Fig. 1 is shown in a cross-sectional view along the cut plane EE in Fig. 7, similar to Fig. 4. The stationary jaw alone and the rigid connection by means of which the threaded retaining plate bears the component are shown. [Figure 9] The gripping device of FIG. 1 is shown similarly to FIG. 2 after pivoting of the jaws is complete. [Figure 10]The gripping device of Fig. 1 is shown in a cross-sectional view along the section plane CC in Fig. 9, similar to Fig. 8. The stationary jaw alone and the precise positioning by pinning using a retaining plate bearing the components are shown. [Figure 11] FIG. 11 shows diagrammatically an exploded side view of the basic components of a spring collet that can be used to manufacture a gripping device according to one of FIGS. 1 to 10 having an inwardly tapered cone; [Figure 12] 13A-13C show schematic exploded side views of the basic components of a spring collet that can be used to manufacture a gripping device according to another embodiment having an outwardly tapered cone. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The invention relates to a gripping device 100 for holding, centering and / or collet-clamping a micromechanical or horological component 200 in a clamping chamber delimited by a collet comprising at least one movable jaw 2 .

[0018] More specifically, in the non-limiting version shown in the figures, the invention relates to a gripping tool with a collet having a number of substantially concentric jaws distributed around a collet axis D. However, the principles of the invention explained below are also applicable to other manufacturing tools of the vice type, or to special tools with movable jaws.

[0019] In an alternative non-limiting embodiment shown in the figures, the invention can be accomplished by modifying a commercially available collet 80 (of the "Ottet" type or similar) to add precision reference bearing points.

[0020] The reference bearing points allow for precise positioning of the components by clamping them.

[0021] The illustrated example relates to the use of a standard collet as the clamping base: a standard collet 80 of the "Ottet" type or similar is modified at low cost.

[0022] This modified collet is intended to be assembled to a pallet 40 fitted with a standard interface 41. This interface 41 is available from suppliers such as "Erowa", "Yerly", "TG-Colin" etc. to make it interchangeable and to equip any type of machine with this fastening means. In an alternative embodiment, this device can also be directly attached to any shank nose.

[0023] The components can be tightened / untightened either manually, for example from outside the machine, using screws or rings, or automatically, and in a non-limiting embodiment, using a control rod to which the machine is fitted.

[0024] The gripping device 100 includes a cone 30. The cone 30 is the element that allows the opening and closing of the collet according to its inward / outward taper, respectively. This is shown in Figure 11 (inwardly tapered cone) and Figure 12 (outwardly tapered cone).

[0025] To modify the standard collet used, the invention splits the role of the collet segments, in this case consisting of a number of moving jaws 2 and a number of stationary jaws 3, into two separate functions. In particular, in a non-limiting embodiment, half of the segments can be shared between each function to achieve balance. Any other combination is possible depending on the constraints specific to the manufacturing operation to be performed.

[0026] The first function remains the basic function of the gripper: clamping / unclamping the component 200 while ensuring centering.

[0027] The second function consists of eliminating clamping / unclamping motion and stiffening the segments with a rigid connection to provide a fixed reference bearing point. To eliminate this motion in certain desired segments, the cones that actuate those particular segments must first be removed / machined.

[0028] The movable jaw 2 allows clamping / unclamping of the component 200 (first function), while the stationary jaw 3, which are rigidly connected to each other, forms a reference bearing point (second function).

[0029] The movable jaw 2 is actuated by the cooperation of, on the one hand, an inwardly or outwardly tapering control cone 30 driven by a tightening screw 90 arranged to push a pushing means 50 (specifically a ball or pushing piece shuttle) through the pallet 40, and, on the other hand, a complementary advancement surface 23 (specifically a conical surface included in the movable jaw 2 integrated in a collet 80). The pushing means 50 is combined with an axially elastic return means 51, such as a spring, this cone 30 comprising a conical surface 32. It goes without saying that the conical surface of the cone 30 may be replaced by other surfaces of the advancement shape.

[0030] That is, according to the invention, at least one of the movable jaws 2 or the stationary jaws 3, or at least some of the movable jaws 2 and / or the stationary jaws 3 if the collet comprises several jaws, comprises a reference surface 20 arranged to support the component 200 directly abutting from the front, or a reference surface 20 arranged to support an intermediate holding plate 400 directly abutting from the front on the component 200, which intermediate holding plate 400 is arranged to abut from the front on the component 200. The gripping device 100 is arranged to perform clamping using a reference bearing point. The gripping device 100 comprises a stationary jaw 3 arranged to support the abutting component 200 with this reference surface 20, and a movable jaw 2 arranged to center and / or clamp the component 200 or the intermediate holding plate 400.

[0031] That is, the gripping device 100 includes movable jaws 2 arranged to center and / or clamp the component 200 and / or the intermediate holding plate 400. The intermediate holding plate 400 abuts against the reference surface 20 and acts as a support for the abutting component 200. The movable jaws 2 include recesses 24 that are made around the intermediate holding plate 400 to provide a clearance that allows the movable jaws 2 to elastically deform and move towards the collet axis D to clamp the component 200.

[0032] In detail, the gripping device 100 comprises a stationary jaw 3 including a reference surface 20 arranged to support an abutting component 200, and a movable jaw 2 arranged to center and / or clamp the component 200 and / or an intermediate holding plate 400, which abuts the reference surface 20 and acts as a support for the abutting component 200. The gripping device 100 is arranged to hold the stationary jaw 3.

[0033] In detail, the gripping device 100 comprises a pallet 40 including gripping means 41 arranged to cooperate with tools and / or handling devices so as to be aligned along the collet axis D, and an actuation device arranged to control the opening and closing of the collet.

[0034] In one particular embodiment, the actuation device comprises a ring that rotates about the collet axis D to control the closure of the collet by compressing a movable jaw 2 contained in the collet.

[0035] In another particular embodiment shown in the figures, the gripping device 100 comprises an operating means 90, such as a screw, nut or a push or pull rod, which actuates a pressing means 50 on the elastic support through or around this pallet 40 along the collet axis D, and an inwardly or outwardly tapering cone 30 comprising an advancement surface 32, in particular a conical surface. The advancement surface 32 is arranged to cooperate with a complementary surface 23 comprised in the movable jaw 2 and / or the stationary jaw 3, constituting a surface for actuating the collet 80.

[0036] In particular, only the movable jaw 2 includes such a complementary surface 23 , the stationary jaw 3 does not have such a complementary surface 23 .

[0037] In particular, the movable jaw 2 on the one hand and the stationary jaw 3 on the other hand are rotationally symmetrical with respect to the collet axis D.

[0038] In particular, there are an equal number of movable jaws 2 and stationary jaws 3 .

[0039] The drawings show a screw used as the manual means of clamping / unclamping the collet, however if the machine is equipped with a control rod that passes through the center of the pallet, this control rod may replace the screw acting as the automatic clamping / unclamping means if it is strong enough.

[0040] It goes without saying that the position indexing, and in particular the indexing of the angular position of the component 200, can be achieved by the simplest and cheapest pin. This pin can be present in the stationary jaw 3 or in the holding plate that holds the stationary jaw 3. The figure shows the case where the pin 39 is attached inside the holding plate. The holding plate is pinned to a spring collet. In an alternative embodiment, when working with standardized blanks with datums, such as notches, it can be advantageous to have a holding plate with a stationary jaw with one orientation, i.e. with a different recess for each datum. The holding plate can be changed without the need to add pins or machine drops in the recesses. If the workpiece has a rolled indexing surface or dihedral angle, a pin in the holding plate or an orientation counterform machined directly in the holding plate can take over the indexing. It will be understood that using different intermediate holding plates adapted to the manufacture of each type of component is cheaper than machining jaws, which may be irreversible.

[0041] In short, the present invention allows for the cost-effective manufacture of a gripping device that ensures both accurate positioning and accurate clamping of components. In particular, the gripping device can be manufactured by modifying widely accepted and widely used standard clamping means such as "Ottet" type collets and the like.

[0042] The present invention improves the precision of machining, particularly rework machining, since the reference bearing points allow good positioning repeatability.

[0043] The invention is easy to identify due to the distinction between the stationary segment (there is no actuation cone and the stationary segment is rigidly connected by a retaining plate) and the presence of the reference bearing points on the stationary segment.

[0044] The compactness of the present invention perfectly matches the trend towards miniaturization of micromechanical machining tools, with overall dimensions that precisely match the dimensional requirements of today's micromachines, while incorporating additional functionality.

Claims

1. A gripping device (100) for holding, centering and / or clamping a micromechanical or horological component (200) in a clamping chamber defined by a collet including at least one movable jaw (2) movable toward a central axis, characterized in that at least one of the movable jaws (2) or stationary jaws (3), or at least some of the movable jaws (2) and / or stationary jaws (3) in case the collet includes a plurality of jaws, includes a reference surface (20) arranged to support a component (200) in direct axial contact therewith, or includes a reference surface (20) arranged to support an intermediate holding plate (400) in direct axial contact therewith, against which the component (200) abuts in axial contact therewith; The gripping device (100) is arranged to clamp using the reference surface (20); the gripping device (100) includes the stationary jaw (3) arranged to support the component (200) in contact with the reference surface (20) and the movable jaw (2) arranged to center and / or clamp the component (200) and / or the intermediate holding plate (400); A gripping device (100) at

2. characterised in that the gripping device (100) comprises the movable jaw (2) arranged for centreing and / or clamping the component (200) and / or the intermediate holding plate (400), the intermediate holding plate (400) abutting against the reference surface (20) and acting as a support for the abutting component (200), The gripping device (100) of claim 1, further characterized in that the movable jaw (2) includes a recess (24) that is made around the intermediate retaining plate (400) to provide a gap that allows the movable jaw (2) to elastically deform and move toward the central axis, the collet axis (D), to clamp the component (200).

3. Features: said gripping device (100) comprising said stationary jaw (3) including said reference surface (20); the stationary jaw (3) is arranged to support the component (200) in abutment; the movable jaw (2) is arranged to center and / or clamp the component (200) and / or the intermediate holding plate (400); said intermediate retaining plate (400) abuts against said reference surface (20) and acts as a support for the abutting component (200); 2. The gripping device (100) of claim 1, wherein the gripping device (100) is arranged to hold the stationary jaw (3).

4. Features: The gripping device (100) is aligned along the central axis, the collet axis (D), a pallet (40) including gripping means (41) arranged to cooperate with a tool and / or a handling device; an actuation device arranged to control the opening and closing of said collet; The gripping device (100) of claim 1, comprising:

5. Features: such that the gripping device (100) is aligned along the collet axis (D), a pallet (40) including gripping means (41) arranged to cooperate with a tool and / or a handling device; The actuation device; Including, 5. The gripping device (100) according to claim 4, wherein the actuation device comprises a ring rotatable about the collet axis (D) to control the closure of the collet by compressing the movable jaw (2) contained in the collet.

6. Features: such that the gripping device (100) is aligned along the collet axis (D), a pallet (40) including gripping means (41) arranged to cooperate with a tool and / or a handling device; The actuation device; Including, said actuation device comprising a pushing means (50) on an elastic support, an inwardly or outwardly tapered cone (30) including a conical surface (32); 5. The gripping device (100) of claim 4, wherein the conical surface (32) is arranged to cooperate with a complementary surface (23) included in the movable jaw (2) and / or the stationary jaw (3) to form a surface for actuating the collet.

7. 7. A gripping device (100) according to claim 6, characterized in that only the movable jaw (2) comprises said complementary surface (23), and the stationary jaw (3) does not have said complementary surface (23).

8. 2. The gripping device (100) according to claim 1, characterized in that the movable jaw (2) and the stationary jaw (3) are alternated.

9. 9. The gripping device (100) according to claim 8, characterized in that the movable jaw (2) on the one hand and the stationary jaw (3) on the other hand are rotationally symmetrical with respect to the central axis, the collet axis (D).

10. 9. The gripping device (100) according to claim 8, characterized in that said movable jaws (2) and said stationary jaws (3) are present in equal number.

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