CH706901B1 - Clock-watch barrel. - Google Patents

Abstract

The invention relates to a clock shaft (1) having a hook (3) for hooking an inner coil of a mainspring in a single winding direction (S), and comprising on a first part of its periphery at the hook (3) and downstream of the hook in said winding direction (S), a spring bearing surface (6) for supporting the inner coil. The shaft (1) comprises, upstream of the hook (3) in the winding direction (S), a planar clearance surface (8) flush with respect to the spring bearing surface (6), and limited by a flat end surface (9) of the hook (3). The invention also relates to a method of manufacturing such a shaft (1) in which the planar clearance surface (8) is made by reaming with respect to the spring bearing surface (6) and located upstream. hook (3) in the winding direction (S).

Description

Field of the invention

The invention relates to a watch barrel shaft having a hook for attaching an inner coil of a mainspring in a single winding direction, and having on a first portion of its periphery at level of said hook and downstream of said hook in said winding direction, a spring bearing surface for the support of such an inner coil.

The invention also relates to a watch cylinder, comprising at least one mainspring lock spring, and such a barrel shaft arranged for receiving said at least one mainspring.

The invention also relates to a timepiece comprising at least one such barrel.

The invention also relates to a manufacturing method of a watch-wheel shaft pivoting about a pivot axis and having a hook for hooking an inner coil of a mainspring in a single winding direction, and comprising on a first portion of its periphery at said hook and downstream of said hook in said winding direction, a spring bearing surface for the support of such an inner coil.

The invention relates to the accumulation of energy in clockwork mechanisms, and more particularly the engine barrels, ringing barrels, and the like.

Background of the invention

The shaft of a watch cylinder is a small component that is subject to significant effort, which requires a particularly careful realization. Its geometry makes its machining generally quite expensive, especially because of the presence of the hook, which requires machining all around its periphery, to ensure a good attachment of the spring, and secondly to ensure the assembly of the eyelet of this spring with sufficient clearance.

The barrel spring is also a highly stressed component, and the design of the shaft must be made to ensure optimal winding, at the inner turns in particular. In particular, the second turn must be positioned on the first inner turn with the least possible variation of curvature, so as to avoid accelerated fatigue aging.

Summary of the invention

For this purpose, the invention relates to a watch barrel shaft having a hook for attaching an inner coil of a mainspring in a single winding direction, and comprising on a first part from its periphery at the level of said hook and downstream from said hook in said winding direction, a spring bearing surface for supporting such an inner turn, characterized in that said shaft comprises, upstream of said hook in said winding direction, a planar clearance clearance surface with respect to said spring bearing surface.

According to a feature of the invention, said planar clearance surface is parallel to a pivot axis about which said shaft rotates, and said planar clearance surface is limited by a flat end surface of said hook.

The invention also relates to a watch cylinder, comprising at least one mainspring lock spring, and such a barrel shaft arranged for receiving said at least one mainspring, characterized in that said hook has a radial projection relative to said flat plane of clearance which is at least equal to the thickness of the inner coil of said spring, in that said eyelet bears on said flat end surface when winding said spring and in that said planar clearance surface and said end planar surface together define a cavity for receiving the free end of said inner coil so as to maintain said free end recessed with respect to a turn of said spring by bearing on a downstream portion located at the downstream end of said spring bearing surface in said winding direction.

The invention also relates to a timepiece comprising at least one such barrel.

The invention also relates to a manufacturing method of a watch-dog shaft pivoting about a pivot axis and comprising a hook for hooking an inner turn of a mainspring in a single winding direction, and comprising on a first portion of its periphery at said hook and downstream of said hook in said winding direction, a spring bearing surface for the support of such an inner turn, characterized in that, in the manufacture of said shaft, there is provided a flat clearance clearance surface with respect to said spring bearing surface and located upstream of said hook in said winding direction.

Brief description of the drawings

Other features and advantages of the invention will appear on reading the detailed description which follows, with reference to the accompanying drawings, in which: <tb> fig. 1 <SEP> shows, schematically and in end view, a cylinder shaft according to the invention, having a planar clearance clearance surface with respect to the barrel spring bearing surface, forming a dihedral with a planar end surface of the hook hook of this spring; <tb> fig. 1A <SEP> represents the tree of FIG. 1, on which is wound the inner turn, only shown, of a mainspring; <tb> fig. 1B <SEP> represents the same shaft, equipped with the same spring, which is illustrated in the following coil winding superposition on the inner coil; <tb> fig. 2 <SEP> shows, schematically and in elevation, the shaft equipped with the spring according to FIG. 1A; <tb> fig. 3 <SEP> shows, schematically and end-to-end, the machining by milling of the planar clearance surface and the flat end surface of the hook, with a first configuration of a cylindrical mill performing butt machining the flat surface clearance, and the machining of the flat surface of the hook with its cylindrical portion; <tb> fig. 3A <SEP> represents the same machining, in the inverse working configuration of the milling cutter; <tb> fig. 4 <SEP> represents the machining of a clearance surface of the hook with a cylindrical cutter, in combination with milling movement along the Z axis and the rotation of the shaft along an axis C; <tb> figs. 5 and 6 <SEP> represent, in end and elevation view, the machining of upper and lower faces of the hook, corresponding to the width of the spring eyelet, in combination of movement of the linear axes and an axis VS; <tb> fig. 7 <SEP> represents another way of making this hook width setting with a form tool; <tb> fig. 8 <SEP> represents the contouring of a helical spring bearing surface, in combination of motion of a shaft C at the level of the shaft, and a large-diameter milling cutter; <tb> fig. 9 <SEP> represents the profile of a drawn bar made by drawing, suitable for the simplified embodiment of a shaft according to the invention.

Detailed Description of the Preferred Embodiments

The invention relates to a watch barrel shaft 1 having a hook 3 for the attachment of an inner coil 4 of a barrel spring 5 in a winding direction S single. This shaft 1 comprises, on a first part of its periphery at the hook 3 and downstream of the hook 3 in the winding direction S, a spring bearing surface 6 for the support of such an inner turn 4 .

Naturally, a barrel 100 having a shaft 1 according to the invention may comprise several springs barrels, hooked to as many hooks. The invention is here described in the most common case of a single spring, it is generalizable without particular modification for a multi-spring arrangement.

According to the invention, the shaft 1 comprises, upstream of the hook 3 in the winding direction S, a flat clearance surface 8 which is flush with respect to the spring bearing surface 6.

Preferably, the planar clearance surface 8 is parallel to a pivot axis D about which the shaft 1 pivots, and the flat clearance surface 8 is limited by a flat end surface 9 of the hook 3. This flat surface 9, which is on the upstream side of the hook 3 in the winding direction S, constitutes the bearing surface for the eyelet 51 of a spring 5.

The flat clearance surface 8 stripped from the bearing surface 6 of the mainspring spring, forms a dihedral with a flat end surface 9 of the hook 3 of attachment of this spring 5. This dihedron is arranged to facilitate the machining of the shaft 1.

Advantageously for manufacturing, the flat clearance surface 8 and the flat end surface 9 of the hook 3 are preferably perpendicular or form with each other an obtuse angle. The flat clearance surface 8 is delimited by a first upstream edge 81 and a second downstream edge 82, respectively upstream and downstream of which extends the spring bearing surface 6. Preferably, the second downstream edge 82 is the intersection of the flat clearance surface 8 and the flat end surface 9, which are then contiguous. Other embodiments, with clearance at the foot of the hook between the second downstream edge 82 and the end planar surface 9, are also feasible.

For a good holding of the barrel spring 5, the flat end surface 9 is preferably inclined relative to a plane P passing through the pivot axis D and the intersection between the flat surface 8 of clearance and the flat end surface 9, preferably constituted by this second downstream edge 82.

As shown in the figures, the flat end surface 9 is inclined, in the direction of its extension from the pivot axis D, upstream in the winding direction S, with an angle of vertex e between 15 ° and 25 °, at the intersection between the flat plane 8 of clearance and the flat end surface 9.

Preferably, the spring bearing surface 6 comprises a sector of cylindrical type parallel to a pivot axis D about which pivots the shaft 1, and comprises at least one helical sector, in the particular embodiment illustrated. by the figures, where the spring bearing surface 6 comprises, from the hook 3 and in the winding direction S, a helical sector 63, then a cylindrical sector 64.

To accompany the development of the inner coil 4, spring 5 the spring bearing surface 6 has a constant radius or increasing in the winding direction S. The variation of these surfaces naturally depends on the geometry of the coil. shaft 1, and the spring 5 used.

The invention also relates to a watch cylinder 100, comprising at least one mainspring 5 with hooking eye 51, and such a cylinder shaft 1 arranged for receiving this at least one mainspring 5 According to the invention, the hook 3 has a radial projection 31 with respect to the plane clearance surface 8 which is at least equal to the thickness of the inner coil 4 of the spring 5. The eyelet 51 bears on the surface end planar 9 during the arming of the spring 5. The plane clearance surface 8 and the flat end surface 9 together define a cavity 2 for receiving the free end 41 of the inner coil 4, so to maintain this free end 41 recessed with respect to a coil of the spring 5 which is supported on a downstream portion 62 located at the downstream end of the spring bearing surface 6 in the winding direction S.

Thus, this free end 41 of the inner turn 4 does not impede the winding of the end of the first turn 4. Preferably, the transition between the end of the first turn 4 and the next turn 42 is made to promote the recovery of the next turn 42 on the first 4, in particular above the hook 3, and if possible so that the end of the first turn 4 arrives substantially tangentially with a dorsal surface 32 that includes the hook 3. This dorsal surface 32 is advantageously radiated, similarly to the helical surface 63 but with an upper radius, so as to accompany the support of the spring 5 without breaking bend, so that shortly after its passage on the back of the hook 3, in the winding direction S, the next turn 42 comes to full support on the first turn 4. In a particular variant embodiment, the dorsal surface 32 has the same geometric profile as the downstream 62, and preferably is a fragment of a cylindrical surface 64 of axis D, which can advantageously be rough machining.

Thus, preferably the plane clearance surface 8 is delimited by a first upstream edge 81 and a second downstream edge 82, and the spring support surface 6 is scalable constant radius or increasing in the direction of This bearing surface 6 has an upstream bearing surface 61 which extends downstream of the first upstream edge 81, and a downstream bearing surface 62 which extends upstream of the second downstream edge 82. with respect to the direction S. And the radial gap between the downstream bearing surface 62 at the second downstream edge 82 on the one hand, and the upstream bearing surface 61 at the first upstream edge 81 of on the other hand, is greater than or equal to the radial projection 31 of the hook 3 with respect to the second downstream edge 82. Preferably, the upstream bearing surface 61 is a helical surface 63, and the downstream bearing surface 62 is a cylindrical surface 64, each of which constitutes approximately half the periphery of the supporting surface 6.

The invention also relates to a method of manufacturing such a rotary shaft 1 rotating clockwise about a pivot axis D and having a hook 3 for hooking an inner turn 4 of a barrel spring 5 in a single winding direction S, and having on a first portion of its periphery at the hook 3 and downstream of the hook in the winding direction S, a spring bearing surface 6 for the support of such an inner coil 4.

According to the invention, during the manufacture of the shaft 1, there is provided a flat clearance surface 8 in relief relative to the spring support surface 6 and located upstream of the hook 3 in the direction of winding S.

Preferably, during the production of the plane clearance surface 8, a flat end surface 9 of the hook 3 is produced.

In a particular variant of implementation of this manufacturing method, the planar clearance surface 8 is produced, or / and the end planar surface 9, or / and a dorsal surface 32 of the hook 3 by wire drawing, with a profile as visible in FIG. 9. The corresponding drawn bar is then taken in a special form of pliers to continue its machining.

In a conventional embodiment where one starts from a raw material consisting of a bar, or wire or a low-profile blank, the flat surface is advantageously made, that is to say the flat surface of clearance. 8, or / and the flat end surface 9, by rolling milling or end milling. This milling operation is preferably done with a milling cutter 71 of one size or two sizes, whose axis is in a plane perpendicular to the pivot axis D and moved in a plane parallel to the pivot axis D and / or in a plane perpendicular to the pivot axis D.

The figures illustrate different variants.

It is understood that the execution of the planar clearance surface 8, and the flat end surface 9, with the same bur 71, is advantageous, which explains the preferred choice of an obtuse angle, or preferably at a right angle between these surfaces, for execution with a single cylindrical milling cutter 71.

Preferably, machining is performed by milling with a milling cutter 71 to a cylindrical size or with a milling cutter 71 two end sizes.

FIG. 3 shows the simultaneous machining of the surfaces 8 and 9 with the same cutter 71, whose axis F is in a plane orthogonal to the axis D. This milling can be achieved, either by rolling with the axis F describing parallel to the axis D, that is, given the small area of the surface 9 and provided that the diameter of milling cutter 71 is sufficient by tangential docking in the direction T with a surfacing of the surface 8 finishing at the surface 9 or by a direct dive of the cutter 71, in a direction oblique with respect to the surfaces 8 and 9. For a steel shaft 1 with a maximum diameter of 2.5 mm, a milling cutter 71 with a diameter of 2.5 mm mounted on a spindle turning at 10,000 rpm gives good results in the first run. In this variant, the surface 8 is machined with the end of the cutter 71, and the surface 9 with its cylindrical portion.

The variant of FIG. 3A is designed for similar machining, but where the surface 9 is machined with the end of the milling cutter 71, and the surface 8 with its cylindrical part.

FIG. 4 shows the same cutter assembly 71 as FIG. 3 or 3A on a Z axis, used in combination with a rotary axis C coincides with the axis D of the shaft 1, for the production of a dorsal surface 32 of the hook 3, for the support of the next coil 42 spring 4, and a disengagement surface 32A connected to this dorsal surface 32, the small section of these surfaces allowing execution by end milling, as illustrated.

In a particular variant of implementation of this manufacturing method, two side surfaces 33, 34, of delimitation of the hook 3 are produced, in the direction of the pivot axis D of the shaft 1, by bleeding. with a shape tool 72, as visible in FIG. 7.

In another variant embodiment of these surfaces 33, 34, they are executed by end milling, in the same arrangement as for milling flat surfaces 8 and 9, as visible in FIGS. 5 and 6, using a C axis coaxial with the axis D of the shaft 1 in synchronism with a paraxial movement of the cutter 71 in a plane perpendicular to the axis D. For example, a milling cutter 71 of diameter 0, 8 mm, with a speed of 25,000 rpm, is suitable.

In another particular variant, visible in FIG. 8, an upstream bearing surface 61 is developed, and in particular in a helical section version, by milling in combination of rotary and linear axes. Typically the shaft is mounted with its axis D coaxial with an axis C of a lathe or a machining center, while a cutter 71 is mounted on a radial axis of the same machine for end work, or is a cutter 71 of larger diameter mounted on an axis parallel to this axis C and movable relative to it, for a contouring operation.

Naturally these different milling machining operations can perform, in the same operations, the machining of plates 11 on the two or four sides, or similar, that includes the shaft 1, and various examples are illustrated by the FIGS.

In general, the turning surfaces of the shaft 1 are turned after the other machining operations, in particular after the one or more milling operations, in order to eliminate the burrs resulting from the other operations.

As an alternative to milling or turning, it is naturally possible to resort to grinding operations, or other forming or machining processes.

Claims (16)

Clock shaft (1) comprising a hook (3) for hooking an inner turn (4) of a mainspring (5) in a single winding direction (S), and having on a first portion of its periphery at said hook (3) and downstream of said hook in said winding direction (S), a spring bearing surface (6) for supporting such a coil interior (4), characterized in that said shaft (1) comprises, upstream of said hook (3) in said winding direction (S), a planar clearance surface (8) flush with respect to said surface of spring support (6). 2. Shaft (1) according to claim 1, characterized in that said planar surface (8) of clearance is parallel to a pivot axis (D) about which said shaft (1) pivots, and that said planar clearance surface ( 8) is bounded by a flat end surface (9) of said hook (3). 3. Shaft (1) according to claim 2, characterized in that said planar clearance surface (8) and said flat end surface (9) of said hook (3) are perpendicular. 4. Shaft (1) according to one of the preceding claims, characterized in that said planar clearance surface (8) is delimited by a first upstream edge (81) and a second downstream edge (82) respectively upstream and downstream of which extends said spring bearing surface (6). 5. Shaft (1) according to claim 2, characterized in that said flat end surface (9) is inclined relative to a plane (P) passing through said pivot axis (D) and a second downstream edge (82). ) of intersection between said flat plane (8) of clearance and said flat end surface (9). 6. Shaft (1) according to claim 5, characterized in that said flat end surface (9) is inclined, in the direction of its extension from said pivot axis (D), upstream in said direction of rotation. winding (S), with an angle θ at the top at said second downstream edge (82) between 15 ° and 25 °. 7. A watch cylinder (100) comprising at least one mainspring (5) with a hooking eye (51) and a drive shaft (1) according to one of claims 1 to 6, arranged for the receiving said at least one barrel spring (5), characterized in that said hook (3) has a radial projection (31) with respect to said planar clearance surface (8) which is at least equal to the thickness of the inner coil (4) of said spring (5), in that said eyelet (51) bears on said flat end surface (9) during the winding of said spring (5), and in that said flat surface of clearance (8) and said flat end surface (9) together define a cavity (2) for receiving the free end (41) of said inner coil (4) so as to maintain said free end (41) in withdrawal relative to a turn of said spring (5) bearing on a downstream portion (62) located at the downstream end of said surface of spring support (6) in said winding direction (S). 8. Timepiece (200) comprising at least one barrel (100) according to claim 7. 9. A method of manufacturing a clock-bearing shaft (1) rotatable about a pivot axis (D) and comprising a hook (3) for hooking an inner turn (4) of a barrel spring (5) in a single winding direction (S), and having on a first portion of its periphery at said hook (3) and downstream of said hook in said winding direction (S), a surface spring support (6) for the support of such an inner turn (4), characterized in that, during the manufacture of said shaft (1), a planar clearance surface (8) is made with respect to said spring bearing surface (6) and located upstream of said hook (3) in said winding direction (S). 10. Manufacturing process according to claim 9, characterized in that, during the production of said planar clearance surface (8), a flat end surface (9) of said hook (3) is produced. 11. The manufacturing method according to claim 9 or 10, characterized in that said plane surface or / and a dorsal surface (32) of said hook (3) is made by drawing. 12. Manufacturing process according to claim 9 or 10, characterized in that said plane surface is produced by rolling milling or end milling, with a milling cutter (71) whose axis is in a plane perpendicular to said pivot axis ( D) and moved in a plane parallel to said pivot axis (D) and / or in a plane perpendicular to said pivot axis (D). 13. Manufacturing process according to one of claims 9 to 12, characterized in that two side surfaces (33; 34) of delimitation of said hook (3) in the direction of a pivot axis (D) of said shaft (1) by bleeding with a form tool (72). 14. Manufacturing method according to one of claims 9 to 13, characterized in that it achieves an upstream bearing surface (61) scalable milling in combination of rotary and linear axes. 15. The manufacturing method according to one of claims 12 to 14, characterized in that said machining is performed by milling with a milling cutter (71) to a cylindrical size or with a milling cutter (71) two end sizes. 16. The manufacturing method according to one of claims 9 to 15, characterized in that it carries out turning surfaces of said shaft (1) after the other machining operations so as to eliminate the burrs resulting from said other operations. .