EP0939350A2 - Chain drive unit for the weight drive a clock - Google Patents

Abstract

The sprocket assembly for the weight drive of the running gear and / or the striking mechanism of a watch consists of a sprocket (22) arranged between two coaxial profile disks (20, 21) on a shaft (1), which in the direction of drive rotation has a directional lock with an axially on the shaft (1) fixed drive gear (7) is in rotary connection and is pressed with its two profile disks (20, 21) by a spring in the axial direction against the drive gear (7). The sprocket (22) and the first profile disk (20) located between it and the drive gear (7) are connected to one another in a rotationally fixed manner at least in the drive direction by a coupling element (14). This profile disc (20) has at least one axially movable spring tongue (31 to 34) which engages in a support surface ring (9) of the drive gear. The second profile disk (21) is designed as a locking spring washer and holds together the otherwise loose parts on the shaft (1).

Description

The invention relates to a sprocket assembly for the Weight drive of the drive and / or a hammer mechanism a watch with a sprocket between two coaxial Profile washers, each with a radial Supporting shoulder provided with an outwardly projecting flange ring have, is arranged on a shaft, wherein the sprocket in the direction of rotation via a directional lock with a drive gear axially fixed on the shaft is in rotation and together with his two profile disks by a spring in the axial direction is pressed against the drive gear.

In the known sprocket assemblies of the generic type The directional lock consists of one with the sprocket non-rotatably connected ratchet wheel and from a spring with pawl engaging the teeth of this ratchet wheel, on a bearing pin of the drive gear is stored.

The drive gear itself is axially fixed on the shaft attached. In most embodiments of the known Sprocket assemblies are the drive gear either pressed directly onto the shaft or on a bearing bush attached, which in turn pressed onto the shaft is.

The two enclosing the sprocket between them Profile washers each have an annular support shoulder, on which the meshes with the sprocket standing link chain or guided over the chain wheel supports. In addition, these profiles are each with one adjoining the support shoulder Provide flange ring to guide the vertical Chain sections in the area of the sprocket serves.

The ring-shaped inside the support shoulders Sections are different for the two profile disks educated. While with the drive gear facing the outside of the ratchet wheel of the directional lock, which is arranged at one in the on the same level as the ring wall lying on the flange ring, is the opposite profile disc in the center with a slightly conical ring section Mistake.

The two profile disks, the sprocket in between and the ratchet wheel are connected to one another in a rotationally fixed manner on a common bearing bush, which sits loosely on the common shaft.
These four components form a sub-assembly with the bearing bush holding them together, while a second sub-assembly is formed by the shaft and the pressed-on drive gear, on which the pawl of the locking mechanism and the engagement spring acting thereon are mounted or fastened. The spring, which holds these two assemblies together on the common shaft, consists of a centrally perforated washer with three or more radial spring tongues, which rest on the flange ring of the profiled washer facing it, while the central washer is supported on a locking washer located in a groove in the shaft .

Thus, this known sprocket assembly consists of a total ten individual parts, of which five, namely the two profile disks, the sprocket in between and the ratchet wheel of the directional lock, with a bearing bush assembled and connected to a first subassembly must be, while four other components, namely the Shaft, the drive wheel, the pawl and the pawl spring assembled into a second sub-assembly must be before the entire sprocket assembly completed with the help of the spring and the lock washer can be. In addition, to achieve a better press fit of the drive gear in the shaft the section where the gear sits with a corrugation must be provided.

These conventional sprocket assemblies are one hand because they consist of many individual components and, on the other hand, because they require significant assembly work very expensive to manufacture.

A sprocket assembly is already known (DE-PS 25 100), in which the sprocket consists of two conical, cast There are disks that are wedge-shaped in cross section Form a cavity between them in which the weight chain is carried along. The directional lock, via which the drive gear wheel stuck on its shaft is in drive connection with the chain wheel, can consist of a ring of ratchet teeth on the End face of the sprocket is arranged and through a axially effective compression spring with the spokes of the drive gear is kept engaged.

Another embodiment provides that the sprocket one on its end facing away from the drive gear Has ratchet. Reach into this ring gear two fingers of a leaf spring like pawls one that is connected to the shaft by means of a pin connection is rotatably attached.

This construction is also particularly complex in terms of assembly technology.

The invention has for its object a sprocket assembly of the kind mentioned in the introduction to create the a minimum number of easy to manufacture and easy, in particular automatically mountable individual parts exists and is therefore cheaper with the same functional quality can be produced.

This object is achieved in that the sprocket and between that and the drive gear lying first profile disc by a coupling element at least in the drive direction rotatably with each other are related and that these are preferably from Spring steel sheet existing profile washer at least one axially movable spring tongue integrally connected to it has that in the manner of a pawl in a concentric Support surface ring of the drive gear engages and that the second preferably also from spring steel sheet existing profile washer as a spring washer trained and as such with several radial Lock spring tongues is provided, the inner locking or Support the locking edges with radial pressure on the shaft and thereby axially resiliently against the Sprocket and this with the first profile disc against press the drive wheel.

In the solution according to the invention, this is conventional Ratchet wheel replaced by the gear rim support surface and the one usually engaged with the ratchet wheel Pawl (cone), which takes the drive wheel in the drive direction is replaced by at least one axially movable spring tongue which with the support surface ring, functionally equivalent as the pawl is engaged.

While it is not necessary in the conventional sprocket assemblies to provide a rotationally fixed connection between the sprocket and the profiled washer separating the sprocket from the drive gear, in the sprocket assembly according to the invention this profiled washer, which is arranged between the sprocket and the driven gear, also acts as a coupling connecting element, which inevitably entrains the Drive gear in the drive direction. In the opposite direction of rotation of the sprocket, there is no entrainment due to the directional lock existing between the profile disk and the drive gear, which consists of the spring tongue and the supporting surface ring.
The sprocket assembly designed in this way has at least three components fewer than the conventional sprocket assemblies and is therefore much cheaper to manufacture than the conventional sprocket assemblies.

By the embodiment according to claim 2 is another Advantage achieved in that the drive wheel no longer must be pressed onto the shaft, which is a less expensive Assembly enables.

At the same time, another component, namely the separate one Spring, which holds the sprocket with the two profile disks presses against the axially fixed drive gear, saved become. In addition, there is no design the second profile washer as a spring washer the axial Lock washer, on which the spring washer with the conventional sprocket assemblies.

The embodiment according to claim 3 not only has the advantage that the supporting surface ring is an integral part of the drive gear, but the additional advantage that the supporting surface ring with the help of a Punching tool in one step and therefore very inexpensive can be made.

With the embodiment according to claim 4 is a functional good engagement position between the spring tongue or tongues and the support surfaces achieved.

By the configuration according to claim 5, the Force exerted by the chain wheel over the profile disc or its Transfer coupling members to the drive gear is distributed over several coupling elements.

The embodiment according to claim 7 is particularly so far advantageous than the spring tongues in an immediate lying next to the flat surface of the drive gear Are arranged level and thus from the drive gear even have the smallest possible axial distance, so that they practically do not bend when transferring power be claimed. In addition, the spring tongues in the form provided for in claim 7 also simply in one piece using a punching and embossing tool generate in the profile disc, which is not only a significant Reduction in manufacturing costs compared one or more pawls, their storage and whose pawl springs means.

Also compared to the embodiment known from DE-PS 25 100 this configuration is considerably less expensive, because no sprocket is attached to the sprocket body must become.

There is also the possibility, according to claim 7 to arrange the spring tongues with their ratchet tooth surfaces so that only some of these ratchet tooth surfaces with the Support surfaces of the drive gear mesh simultaneously stand while other locking surfaces of other detent springs for example by half a division of the supporting surface ring staggered with its support surfaces reach. In this way you can divide the supporting surface ring reduce effectiveness, e.g. cut in half. This also makes it possible to break through the support surface ring to choose so large in cross section that them without further ado, for example in the fine stamping process, can be punched.

Further advantageous embodiments of the invention are Subject matter of claims 9 to 12.

Due to the inventive design of the individual parts, of which the sprocket assembly is composed, this sprocket assembly can also be easily automatically assemble because all parts except the one with the Locking springs provided second profile washer, loose let it slide on the shaft. But also the second, at the same time Profile disc designed as a locking spring washer, can be done with a simple device without large Force in their intended position on the shaft push. There will be no special ones for manual assembly Assembly tools needed.

Fig. 1

eine Kettenradbaugruppe in Schnittdarstellung;

Fig. 2

Teile der Kettenradbaugruppe aus Fig. 1 mit einer anderen Welle;

Fig. 3

das Kettenrad der Fig. 1 in Seitenansicht;

Fig. 4

das Antriebszahnrad der Fig. 1 in Seitenansicht;

Fig. 5

die zwischen dem Kettenrad und dem Antriebszahnrad angeordnete Profilscheibe in Seitenansicht;

Fig. 6

einen Schnitt VI-VI aus Fig. 5;

Fig. 7

einen Teilschnitt VII-VII aus Fig. 5, bei dem eine Ratschenfeder mit dem Stützflächenkranz des Antriebszahnrades in Eingriff steht;

Fig. 8

das die Kupplungsscheibe und die zwischen dieser und dem Antriebszahnrad liegende Profilscheibe drehfest miteinander verbindende Kupplungelement in Stirnansicht;

Fig. 9

die zweite Profilscheibe in Seitenansicht IX aus Fig. 1.

The invention is explained in more detail below with the aid of the drawing. It shows:

Fig. 1

a sprocket assembly in a sectional view;

Fig. 2

Parts of the sprocket assembly of Figure 1 with another shaft.

Fig. 3

the sprocket of Figure 1 in side view.

Fig. 4

the drive gear of Figure 1 in side view.

Fig. 5

the profile disc arranged between the sprocket and the drive gear in side view;

Fig. 6

a section VI-VI of Fig. 5;

Fig. 7

a partial section VII-VII of Figure 5, in which a ratchet spring is engaged with the support surface ring of the drive gear.

Fig. 8

the coupling element and the lying between this and the drive gear profile disc rotatably connecting coupling element in front view;

Fig. 9

the second profile disc in side view IX of FIG. 1st

The sprocket assembly shown in the drawing is from a shaft 1, the two journals 2 and 3 as well has a radial ring shoulder 4. On this ring shoulder 4 lies on the face with the edge 5 of its central Bore 6 a drive gear 7, which in itself is loosely arranged on the shaft 1 and the spur gear 8 has. This drive gear 7 is with a support surface ring 9, which consists of several, in essentially rectangular or trapezoidal or breakthroughs 10 like ring segment. These breakthroughs 10 are, as can best be seen from FIG. 4, at equal angular intervals α from one another in a Bore 6 or circular ring concentric to the shaft axis 12 11 arranged. In the illustrated embodiment the support surface ring 9 contains a total of twelve openings 10, so that their angular distances α are 30 ° in each case, with which the division α of the supporting surface ring 30 ° is.

Although basically any number of breakthroughs it would be conceivable to use one by the number To provide "4" divisible number of openings 10 so that as explained in more detail in the following description which engages in this support surface ring 9 Spring tongues can take effect in pairs.

On the opposite side of the ring shoulder 4 Drive gear 7 is rotatable on the shaft 1, a coupling element 14 arranged. This coupling element 14 consists of a socket 15 with a hexagonal outer profile 16 and a cylindrical bore 17, the Diameter corresponds to the outer diameter of shaft 1, so that the bushing 15 on the shaft 1 with little play is freely rotatable.

Between two profile disks, namely a first profile disk 20 and a second profile disc 21 is on the coupling element 14 has a sprocket 22 which eight commonly shaped teeth 23 and a central opening 24 with a hexagonal profile 25. This Hexagon profile 25 is on the hexagon outer profile 16 of the coupling element 14 so matched that the coupling element 14 over the hexagonal profile 25 with the sprocket 22 is positively and thus non-rotatably connected.

The axial length of the coupling element 14 is dimensioned that they have little axial play between the Drive gear 7 and the radial locking springs 57 of the second profile disc 21 extends.

The first profile disk 20, which is shown in FIGS. 5 and 6 is shown as a single part, has a central Breakthrough 26 on, also with the same hexagon profile 25 is provided. Through this hexagon profile 25, the profile disc 20 is positive and thus rotatably via the coupling element 14 with the sprocket 22 in connection.

The coupling element 14 could also consist of a cylindrical Bush exist that only have a driving surface has its scope. Accordingly, they would also have to Openings 24 and 26 of the chain wheel and the profile disc 20 profiled.

The preferably also made of spring steel sheet first profile disk 20 has a support shoulder 27, to which a ring flange projects radially outwards 28 connects.

Within the support shoulder 27, the first profile disc has 20 a lying in the plane of the flange ring 28, plane ring wall 29, in which a total of four spring tongues diametrically opposite each other in pairs 31, 32 or 33 and 34 in the form of free cut Ring wall sections are arranged. Cut freely means that the spring tongues 31 to 33 each in ring segment-shaped cutouts 36 and 37 of the ring wall 29 lie and in one piece with the remaining Parts of the annular wall 29 are connected. As from Fig. 1 and 6 can be seen, the support shoulder 27 consists of the outer portion of a V-shaped ring bead 26.

These spring tongues 31 to 34 are on the same Annular ring 11 as the support surface ring 9, and they are each with radial locking tooth surfaces 41 and 42 or 43 and 44, each with one of the same radially extending support surfaces 13 of the openings 10 of the support surface ring 9 can engage, such as which is shown for example in Fig. 7. Are there the axially resilient end portions 45 of all spring tongues 31 to 34 by appropriate embossing against the drive gear 7 in its plane to the outside what is offset by an appropriate embossing tool happens. As can be seen from Fig. 7, there is between put in the plane of the drive gear 7 End sections 45 and the remaining subsections of the Spring tongues 31 to 34 each have an oblique connecting section 46. If the sprocket 22 in the direction of the elevator, that is against the drive direction, compared to the stationary one Drive gear is rotated, cause this oblique connecting sections 46 that they share with the sections 45 axially from the openings 10 in the Level of the annular wall 29 are lifted out.

In the circumferential direction, these are end portions embossed 45 kept so short that they are each complete dip into one of the openings 10 of the supporting surface ring can.

As can best be seen from FIG. 6, the Breakthrough 26 with the hexagonal profile 25 in a central, radially extending wall section 47, the opposite the annular wall 29 and the annular flange 28 by the width of the Support shoulder 27 is offset such that the support shoulder 27 and the outer side facing the chain wheel 22 of the central wall section 47 lie in one plane and can rest together on the sprocket 22.

From Fig. 1 it can be seen that the diameter of the ring flange 28 is smaller than the diameter of the base circle 30 of the spur toothing 8 of the drive gear 7.

As can be seen from Fig. 4, of the twelve available Support surfaces 13 of the support surface ring 9 each two on a line 50 or 51 of the axis cross, which means that those lying on line 50 in each case Support surfaces 13 from the support surfaces lying on line 51 13 have an angular distance β of 90 °.

Of the four ratchet tooth surfaces 41 to 44, which are also diametrically opposed in pairs, should each only two at the same time with two diametrically in pairs opposite support surfaces 13 engage. Therefore, the ratchet tooth surfaces 41 and 42 each have in the drive direction of arrow 35 in front or behind lying ratchet tooth surfaces 43 and 44 each one Angular distance β1 on, by a half pitch α / 2 of the support surface ring 9 or by half the angular distance α / 2 of the support surfaces 13 is smaller than the angular distance β, which the locking tooth surfaces 41, 42 or 43, 44 each closest support surfaces 13 from each other to have. This ensures that when twisting the sprocket 22 or the profile disc 20 opposite the drive gear 7 by half a division α / 2 each other ratchet tooth surfaces 41/42 or 43/44 with the next one in the corresponding direction of rotation Locking surfaces 13 of the support surface ring 9 engage. You achieve the same effect as with a division of the supporting surface ring which is half as large or as with a half the angular distance α of 15 ° between two adjacent support surfaces 13.

Just like the support surface ring 9 with more or less than twelve breakthroughs, it is possible, the profile disc 20 with more or less than four spring tongues. However, it is advantageous a number of supporting surfaces divisible by the number "4" 13 in the drive gear 7 and at least four spring tongues with diametrically opposed pairs Toothed tooth surfaces 41 to 44 to provide the locking tooth surfaces 41 and 42 or 43 and 44 always in pairs the support surface ring 9 or with its support surfaces 13 can engage. This results in a better power distribution and thus greater functional reliability when driving the drive gear 7 by the Sprocket 22 via the spring tongues 31 to 34 of the profile disk 20th

The second profile disk 21 arranged on the side of the chain wheel 22 opposite the drive gear 7 likewise has a support shoulder 27 and a flange ring 28, which are arranged symmetrically with respect to the chain wheel 22 with respect to the support shoulder 27 or the annular flange 28 of the profile disk 20.
On a radial annular wall section 53, which lies within the support shoulder 27, a slightly conically outwardly directed annular wall 54 is formed, which has a central bore 55 and which is divided into a plurality of wedge-shaped locking tongues 57 by a plurality of radial slots 56 arranged in a star shape, eight in the present example is. This second profile plate 21 with its locking tongues 57 is made of resilient material, for example spring steel, so that the locking tongues 57 can be brought into locking engagement with the outer surface 58 of the shaft with their inner end edges 58 and the profile disk 21 at the same time as a locking spring washer for axially fixing the Sprocket 22, the profile plate 20 and the drive gear 7 can be used on the shaft 1.

It may be appropriate to use a shaft 1 To provide annular groove 59 with which the inner end edges 58th the locking springs 57 positively engaged can be.

As can be seen from Fig. 1, the support shoulders serve 27 of the two profile disks 20 and 21 as a support for the chain links 60 of a drive chain 61 with which the teeth 23 of the chain wheel 22 each in a form-fitting manner Stand by.

While the chain wheel 22 is loaded in the drive direction two each of the diametrically opposite Spring tongues 31 to 34 through their locking tooth surfaces 41/42 or 43/44 with two each also diametrically opposite support surfaces 13 of the support surface ring 9 entrainment, that can Sprocket 22 with the first profile disk 20 in the elevator direction, i.e. against the drive direction, relative to Drive gear 7 are rotated, during this Rotational movement ratcheting the spring tongues 31 to 34 over the intermediate webs of the openings 10 of the supporting surface ring 9 slide.

This sprocket assembly is significant for several reasons can be produced at a lower cost than the known ones Embodiments: it consists of only six in total Individual parts exist, which can be produced very inexpensively are, these items only need to be loosely attached to the joint Wave 1 are put off, they will be on the wave 1 through the second profile disk 21 pushed on last fixed on shaft 1, and it's also a fully automatic Assembly possible.

Claims (12)

Sprocket assembly for the weight drive of the running gear and / or a striking mechanism of a watch with a sprocket (22) between two coaxial profile disks (20, 21), each of which has a support shoulder (27) provided with a radially outwardly projecting flange ring (28) , Is arranged on a shaft (1), the chain wheel (22) in the direction of rotation via a directional lock with a axially fixed on the shaft (1) drive gear (7) in rotation and together with its two profile disks (20, 21) a spring is pressed axially against the drive gear (7),
characterized,
that the sprocket (22) and the first profile disk (20) lying between it and the drive gear (7) are connected to one another in a rotationally fixed manner at least in the drive direction by a coupling element (14) and that this profile disk (20), preferably made of spring steel sheet, is at least one axially Movable integrally connected spring tongue (31 to 34), which engages in the manner of a pawl in a concentric support surface ring (9) of the drive gear (7) and that the second profile plate (21), preferably also made of spring steel sheet, is designed as a locking spring washer and as such is provided with a plurality of radial locking spring tongues (57), the inner locking or locking edges (58) of which are supported with radial pressure on the shaft (1) and thereby the profile disk (21) is axially resilient against the chain wheel (22) and this with the first Press the profile disc (20) against the drive wheel (7). Sprocket assembly according to claim 1, characterized in that that the drive gear (7) on a radial Ring shoulder (4) of the shaft (1) can be rotated in contact is mounted on the shaft (1). Sprocket assembly according to claim 1 or 2, characterized characterized in that the support surface ring (9) from a Variety of depressions or openings (10) consists of a concentric to the shaft axis (12) Circular ring (11) arranged and each with a support surface (13) are provided, each of which have the same angular distances (α) from each other. Sprocket assembly according to claim 3, characterized in that that the support surfaces (13) each at least run approximately radially to the shaft axis (12). Sprocket assembly according to one of claims 1, 2 or 3, characterized in that the first profile disc (20) a plurality of circumferentially extending ones Spring tongues (31, 34), each with a on the circular ring (11) of the supporting surface ring (9) radial locking tooth surface (41 to 44) are, each with one of the support surfaces (13) can be brought into engagement. Sprocket assembly according to claim 5, characterized in that that the first profile disc (20) radially inside the support shoulder (27) at least approximately lying in the plane of the flange ring (28) plane ring wall (29) in which the spring tongues (31 to 34) in the form of free cut Ring wall sections are arranged. Sprocket assembly according to one of claims 1, 2 or 3, characterized in that at least one of the multiply existing ratchet tooth surfaces (41, 42) from the one in front or behind in the direction of rotation of the drive Locking tooth surface (43, 44) an angular distance (β1), which is about half a division (α / 2) the support surfaces (13) of the ratchet wreath (9) larger or less than the angular distance (β) that the closest to these locking tooth surfaces (41/42 or 43/44) have lying support surfaces (13) from each other. Sprocket assembly according to one of claims 1 or 3 to 7, characterized in that the supporting surface ring (9) of the drive gear one straight through the Number "4" has a divisible number of support surfaces (13) and that the first profile plate (20) with four diametrically opposite each other in pairs Lock tooth surfaces (41, 42 and 43, 44) is provided. Sprocket assembly according to one of claims 1 to 8, characterized in that the first profile disc (20) and the sprocket (22) through a coupling bush (14) are non-rotatably connected, which at least one driver surface (15) on its circumference by which they are profiled accordingly central openings (24, 26) of the profile disc (20) and the sprocket (22) positively and is non-rotatably engaged. Sprocket assembly according to claim 1 or 9, characterized characterized in that the coupling bush (14) is rotatable is arranged on the shaft (1) and at least approximately from the drive gear (7) to the locking spring tongues (57) of the second profile plate (21) extends. Sprocket assembly according to claim 8 or 9, characterized characterized in that the positive with the Coupling bushing (14) engaged breakthrough (26) of the first profile disc (20) in a central Ring wall section (47) is located opposite the Ring wall (29) with the support surface ring (9) axially to Sprocket (22) is offset. Sprocket assembly according to claim 1, characterized in that that the shaft (1) for locking or locking Inclusion of the inner locking or locking edges (58) of the locking spring tongues with an annular groove (59) is.

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