EP1233314A1 - Clockwork - Google Patents

Abstract

Mechanical clockwork assembly, especially for wrist or pocket watches has a mechanical oscillation system and a mechanical escapement with an escapement wheel (1) and an anchor (3). The functional elements of the escapement wheel are at least partially coated on their operating surfaces with a DLC (diamond like carbon) coating. An Independent claim is made for a mechanical clockwork assembly, especially for wrist or pocket watches with plate, plate element and balance-wheel arbor where the contact surfaces of the moving parts are coated with DLC.

Description

The invention relates to a mechanical clockwork according to the preamble Claim 1 or 11 and preferred, but not exclusively to one Clockwork for pocket and wristwatches.

Movements are known in numerous versions. Increasing popularity Mechanical watch movements have been enjoying themselves again for several years, especially in the movements for pocket watches and wristwatches where a lower one Coefficient of friction and also abrasion must be avoided, i.e. in particular on the bearings of the shafts and on areas of the escapement, i.e. on with the Anchor wheel cooperating areas of the anchor and on with the anchor interacting areas of the vibration system (balance) synthetic rubies use, specifically as a bearing for the shafts, as anchor pallets or Anchor stones and as lever stones on the balance shaft. This also means complex assembly steps.

Furthermore, it is particularly necessary for mechanical movements that these in certain periods must be overhauled to ensure accuracy to restore, i.e. in particular, oil and abrasion residues washed out and the bearings re-oiled, which is usually an at least partial dismantling of the clockwork and subsequent readjustment of the Gangs required.

The object of the invention is to show a clockwork, which is characterized by a high Accuracy and in which the usual maintenance practically not or is only required at very large intervals. To solve this task a clockwork is designed according to claim 1 or 11.

By "DLC coating" within the meaning of the invention, a D iamant- L IKE C arbon hard coating to be understood that on the carbon element is based a diamond-like layer having a high microhardness and with an extremely low friction coefficient. The thickness of this coating is, for example, in the range between 2 and 4 μm. The hardness of such a DLC layer is of the order of 2500 HV or higher. They are manufactured using plasma-assisted chemical vapor deposition, for example at a coating temperature of approx. 150 - 220 ° C. When the coating is deposited, silicon and oxygen atoms can also be added, which results in an even further reduced friction. Such a DLC coating and its production is described for example in WO 98/59089.

"Functional elements" in the sense of the invention are the elements of the vibration system (Balance) and the elements of the escapement in particular the anchor and the escapement wheel. "Other functional elements" in the sense of the invention are also the wheels of the Gear train, the pins and bearings of the clockwork.

As far as the DLC coated functional elements, boards or Board elements are those made of brass, it may be appropriate to the respective surface first a thin layer of a harder metal, For example, to apply a chrome layer in order to improve the adhesion of the DLC layer to reach.

In the case of functional elements, circuit boards or circuit board elements etc. made of steel, in particular Stainless steel, these are preferably one before the DLC coating Subjected to heat treatment, e.g. Vacuum hardening or plasma nitriding.

The invention can be used on the conventional press-in bearings made of synthetic Ruby can be dispensed with. The bearings are then, for example, directly in the board and the board elements (bridges) incorporated and coated by DLC Bearing holes or preferably formed by inserted metal bearings, the then DLC are also coated at least on their bearing surfaces.

In the invention, gears and drives are preferably also velvet Bearing DLC coated, so that this is also compared to conventional Movements significantly reduce the friction of the entire gear train results.

In the clockwork according to the invention there is still the possibility, especially the Bearing journal of the balance shaft as well as the armature shaft compared to the train known movements with an enlarged diameter, because by the DLC coating of these journals and the associated surfaces of the bearings results in very low friction, without impairing function and Accuracy allows an increase in the bearing journal diameter. By the enlargement of the journal diameter results in an improved Shockproof as well as possibly the possibility of using conventional Movements for shock protection provided elements (spring-loaded mounting of the Balance wave) entirely or partially.

Another advantage of a mechanical movement is that the Anchor pallets or anchor pins etc. formed from synthetic stones (rubies) are not are necessary and thus also for the manufacture of these pallets, stones, etc. and the assembly of previously required operations can be omitted.

• Synthetische Einpreßlager, Paletten, Ankersteine, Hebelsteine usw. aus Rubin sind nicht mehr erforderlich.
• Das Uhrwerk bedarf keiner Schmierung, so daß auch die Gefahr eines Verhärtens von Ölen und eine Beeinträchtigung der Ganggenauigkeit hierdurch nicht besteht.
• Durch eine Verringerung der Reibung im gesamten System wird eine absolut stabile Ganggenauigkeit über eine lange Zeit erreicht.
• Eine Wartung des Uhrwerkes ist praktisch nicht mehr erforderlich, allenfalls erst nach einer Vielzahl von Jahren, beispielsweise nach fünf Jahren.
• Durch die hohe Oberflächenhärte wird ein mechanischer Abrieb weitestgehend vermieden. Auch dies trägt zur Erhöhung der Langzeit-Gangstabilität sowie zur Verlängerung der wartungsfreien Zeit bei.
• Durch Vereinfachung der konstruktiven Ausbildung des Uhrwerks ergibt sich eine wesentliche Reduzierung der Fertigungskosten.
• Durch die DLC-Beschichtung wird weiterhin auch ein Korrosionsschutz erreicht und damit Beeinträchtigungen der Ganggenauigkeit sowie auch des Zustandes des Uhrwerks insgesamt selbst bei eingedrungener Feuchtigkeit vermieden.

The main advantages of the invention can thus be summarized as follows:

• Synthetic press-fit bearings, pallets, anchor blocks, lever blocks, etc. made of ruby are no longer required.
• The clockwork does not require any lubrication, so that there is also no risk of hardening of oils and impairing the accuracy of the movement.
• By reducing the friction in the entire system, absolutely stable accuracy is achieved over a long period of time.
• Maintenance of the clockwork is practically no longer necessary, at most only after a number of years, for example after five years.
• Mechanical abrasion is largely avoided due to the high surface hardness. This also contributes to increasing long-term gait stability and extending the maintenance-free time.
• By simplifying the design of the clockwork, there is a significant reduction in manufacturing costs.
• The DLC coating also provides protection against corrosion, thereby avoiding impairments in the accuracy of the clock and in the condition of the movement as a whole, even if moisture has penetrated.

In a preferred embodiment of the invention, the interacting surfaces, for example the bearing surfaces and / or the interacting surfaces in the area of the escapement, for example in the area of the anchor pallet, are designed such that one of these surfaces has the DLC coating and the other the interacting surfaces of silicon carbide (SiC) is formed. For example, the bearings of the clockwork shafts are formed from silicon carbide bearing stones, while the surfaces of the shafts interacting with these bearing stones have the DLC coating. In a similar manner, the anchor pallets are then made of silicon carbide, for example, while the surfaces of the anchor or escapement wheel 1 DLC that interact with these pallets are coated. It has been shown that the combination of DLC coating and silicon carbide results in extremely low coefficients of friction of the order of 0.05-0.02, and this in a very surprising manner, although for example the combination
Silicon carbide / silicon carbide has a significantly higher coefficient of friction and silicon carbide is therefore generally unsuitable as a bearing stone in mechanical watches.

Fig. 1

in vereinfachter Funktions-Darstellung die Anker-Hemmung einer mechanischen Taschen- oder Armbanduhr gemäß der Erfindung;

Fig. 2

in vereinfachter schematischer Darstellung einen Teilschnitt durch die Werkplatine sowie durch eine an dieser Platine vorgesehene Brücke, und zwar im Bereich der Unruh;

Fig. 3

und 4 in vergrößerter Teildarstellung als weitere mögliche Ausführungsformen der Erfindung die Lagerung der Unruh-Welle bzw. des Unruh-Wellenzapfens.

Further advantages and special features of the invention result from the following description of a possible embodiment of the clockwork according to the invention. The invention is explained in more detail below with reference to the figures using an exemplary embodiment. Show it:

Fig. 1

in a simplified functional representation the anchor escapement of a mechanical pocket or wristwatch according to the invention;

Fig. 2

in a simplified schematic representation, a partial section through the work circuit board and through a bridge provided on this circuit board, specifically in the area of the balance;

Fig. 3

and FIG. 4 in an enlarged partial representation, as further possible embodiments of the invention, the bearing of the balance shaft or of the balance shaft journal.

1 shows as a possible embodiment the anchor escapement of an otherwise Mechanical movement of a pocket or not shown in this figure Wristwatch. This inhibition consists in a manner known per se from the remaining clockwork or gear train in an anchorage or drive connection Escapement wheel 1, which by means of its journal 2 in FIG. 1 is not The printed circuit board of the clockwork is mounted and driven with the other, also not shown functional elements of the clockwork is connected, and from the armature 3, which around its bearing journal 4, which is also mounted in the board is pivotable, with a predetermined by the balance 5 Oscillation frequency. The anchor 3 acts for this with its on the arm 3 ' provided fork end 3 "with a on a lever disk 6 of the balance shaft 7th provided driver 8 together.

The armature 3 also has two with the armature wheel 1 or with the teeth there 11 interacting pallets, namely the entrance pallet 9 and the Output range 10. The peculiarity of this anchor escapement includes in that the anchor 3 with the associated pallets 9 and 10 in one piece from metal, is preferably made of stainless steel hardened, and at least to those with Teeth 11 interacting surfaces of the pallets 9 and 10 DLC is coated, and that the escapement wheel 1 at least on the pallets 9 and 10 interacting teeth 11 is also DLC coated. Furthermore, the anchor is 3 at least on its with the driver 8 of the lever disk 6 cooperating fork end 3 "DLC coated. A DLC coating shows also the driver 8 formed by a pin made of metal, for example made of steel on.

In a preferred embodiment of the invention, at least the Bearings 3 and 4 and the balance shaft 7 DLC coated, the associated bearing in the for example made of steel or another suitable Metal-made circuit board in the simplest case formed by simple holes and then at least the areas of these holes DLC forming the bearing surfaces are coated.

This coating results in extremely high surface hardnesses of approx. 2500 HV, so that there is no noticeable wear even without lubrication. Especially in Reference to the anchor escapement can in particular also refer to the pallet 9 there and 10 as well as for the driver 8 (lever block) synthetic rubies that were previously common can be dispensed with, which require an additional, complex assembly step. The Armature 3 can rather be made in one piece with the pallets 7 from metal or steel become. Furthermore, it is also possible for the driver 8 to be particularly simple Way of making metal.

Figure 2 shows a simplified representation of the on the work board 12 and one Another board 13 (bridge) mounted balance 5 with the balance shaft 7. As in the figure 2, the work board 12, the bridge 13 and the balance shaft 7 are shown each provided on the entire surface with the DLC layer 14, which is also stretches into the bearing bores 15 and 16, which for the balance shaft 7 in the Board 12 or bridge 13 are provided. Since both the shaft 7 and that of the holes 15 and 16 formed bearing surfaces DLC are coated, results still an extremely low coefficient of friction, so that the balance pin or Balance shaft 7 compared to known designs also in the area of the bearings stronger, for example with a diameter of 0.2 mm instead of the previous one usual diameter of 0.1 mm can be performed. This results in in any case an improved shock resistance, possibly can also be the usual one Shock protection can be completely dispensed with due to the spring-loaded bearing of the balance shaft 7 can. All other shafts and journals and the associated bearings are also preferred of the clockwork DLC coated, so that on the usual jewels or rubies can be dispensed with, thereby simplifying manufacture at the same time reducing the friction in the entire system and a substantial Improvement in gait stability is possible, without lubrication or Relubrication of the bearings.

All gears are also preferred, at least on their teeth or Provide tooth flanks with the DLC coating, which also includes to decrease friction, to increase gait stability over a long period of time, and Avoiding abrasion helps.

However, the DLC coating also has the advantage that it is very forms effective corrosion protection, so that also corrosion on the circuit board Shafts, on gears and other functional elements of the clockwork effective are avoided.

With 17 two springs are indicated in Figure 2, which serve to protect the shock. Also these springs 17 are at least on their side facing the shaft 7 with the DLC coating Mistake.

So far for the elements described above, for example for the circuit board 12 and / or Bridge 13 or brass is used as the basic material for gears, this is before the DLC coating, preferably with a coating of a harder one Metal, for example made of chrome. Are functional elements made of steel, For example, stainless steel, preferably before the DLC coating Heat treatment, for example vacuum hardening and / or plasma nitriding.

Above it was assumed that the bearing bores 15 and 16 directly in the board 12 or bridge 13 are provided. In practical training it will but be useful, these bearing holes in bushings 15 'and 16' to be provided which are made of stainless steel or hardenable steel, preferably of plasma nitridable Steel (e.g. stainless steel 4301 according to DIN 1.4301) by machining Machined and then also with the DLC layer 14 after hardening are specially provided on the bearing surfaces and in the bridge 13 or in the Board 12 are pressed. The bearing bushes 15 'and 16' can also in Be made of carbide.

The invention was described above using an exemplary embodiment. It it is understood that numerous changes and modifications are possible without thereby leaving the inventive concept on which the invention is based. So is it is also possible, for example, to date, particularly in the case of mechanical watches to retain at least some of the usual synthetic ruby bearings and the counter surfaces interacting with these bearings, namely the surfaces of the To provide the bearing journal with the DLC coating.

Furthermore, it is in particular also possible to use silicon carbide for the Provide waves 2 and 7, while the waves themselves at least on their with the Interacting bearing surfaces that have DLC coating. It has It has been shown that the DLC coating in combination with silicon carbide is too extreme leads to low friction coefficients, in dry air, as in one closed clockwork is assumed to be a coefficient of friction in the Order of magnitude of only 0.02, with high wear resistance both Bearing stones as well as the shafts on their interacting with the bearing stones Surfaces.

There is also the possibility of input and output pallets 9 and 10 also to be made from silicon carbide, the anchor or escapement wheel at least on the escape gear teeth interacting with these pallets Has DLC coating.

FIG. 3 again shows a partial view and enlarges the bearing of the balance shaft 7 or the upper, reduced diameter end 7 'of this shaft. In the lower end of the shaft 7 is the same as that shown in this figure stored, namely in the work board, not shown in this figure.

The shaft 7 is made of hardened stainless steel (for example plasma-nitrided) and in the illustrated embodiment, at least in the area of its section 7 'DLC-coated or with another coating that is also hard Surface with a low coefficient of friction for section 7 'guaranteed.

The shaft 7 is supported with its pin end 7 'in the bridge 13. For this is in one there recess 18 provided a special bearing 19, which is like a ball bearing is executed and from the bearing ring 20 and the spherical bearing elements 21st which the latter directly with the section 7 'of the shaft 7th interact. The bearing ring 20 is suitable, for example by Press fit held in the recess 18. At the center of the shaft 7 facing Underside forms the bridge 13 annular web 22 with an opening 23 through which the pin end 7 'is passed and which has a diameter that something is larger than the diameter of this pin end 7 ', but smaller than that Diameter of the recess 18.

While the circuit board or the bridge 13 is made of brass, for example, the bearing ring 20 is made of hardened stainless steel and is, for example, suitably coated, for example DLC-coated, at least on the surfaces interacting with the bearing elements 21. The bearing elements 21 consist of silicon carbide or synthetic ruby or of a ceramic, for example of Al ₂ O ₃ ceramic. The diameter of the bearing elements is of the order of the pin end 7 ', ie in the embodiment shown the diameter of the bearing elements is approximately 0.3 mm and the outer diameter of the pin end 7' is approximately 0.5 mm.

On the top of the bridge 13 facing away from the work board, not shown the bearing 19 completed by the spring 17, for example made of stainless steel hardened and DLC-coated or made of silicon carbide or synthetic ruby is made. The pin end 7 'is supported against the spring 17.

Another material can also be used as the material and / or coating of the spring, for example silicon carbide, synthetic ruby or Al ₂ O ₃ .

The bearing 19 shown in FIG. 3 is characterized by a construction, which can be implemented easily and inexpensively, in particular the Bearing elements 21 made of silicon carbide, ceramic or synthetic ruby in the required spherical shape easily manufactured. Despite the compared to Bearing end 7 'of relatively large diameter of the bearing elements 21 is the bearing 19 easy to install.

FIG. 4 shows a further possible embodiment of a bearing 19a, which is essentially differs from the bearing 19 in that the bearing ring 20 floating, d. H. Axially movable in the opening 18 in the direction of the ring axis arranged and by two spring elements in the illustrated embodiment are formed by the plate springs 24 and 25, is held axially in the opening 18. The 4, the upper spring element 24 is supported against the spring 17 or one corresponding plate provided on the bridge 13 and the lower spring element 25 on the upper side of the web 22 facing the plate or the spring 17.

The shaft 7a is provided with a pin end 7a 'corresponding to the pin end 7' formed, which tapers in the shape of a truncated cone towards the free end, namely with a cone angle of 40 °. The two spring elements 24 and 25 are like this formed that the force of the spring element 24 is slightly greater than the force of the Spring element 25 so that the spherical bearing elements 21 with little force against the conical surface of the pin end 7a 'of the balance shaft 7a issue.

In the bearing 19a shown in FIG. 4, the spring elements 24 and 25 Disc springs arranged coaxially with the axis of the shaft 7a are provided. Instead of this disc springs can also other suitable spring elements, for example corrugated disc springs can be used. The shaft 7a in turn consists of stainless steel hardened and is DLC-coated at least at the ends 7a '.

Of course, it is also possible to add other parts or functional elements of the To provide the movement with the DLC coating, for example the inner surface of a Spring housing, especially where the spring with its spring end on the Inner surface of the spring housing is present and when winding the clockwork or Spring is taken from the rotating spring housing. Through the DLC coating can then dispense with the previous oiling here.

LIST OF REFERENCE NUMBERS

1

Anchor or escapement wheel

2

armature shaft

3

anchor

3 '

armature lever

3 '

fork end

4

Anchor journals

5

balance

6

roller table

7

Balance shaft or pin

8th

Lever block or driver

9

input range

10

output range

11

Ankerradverzahnung

12

movement plate

13

bridge

14

DLC layer

15, 16

bearing bore

15 ', 16'

Carbide bearings

17

feather

18

recess

19

camp

20

bearing ring

20 ', 20 "

Bearing ring section

21

spherical bearing element

22

drilling

Claims (13)

Mechanical movement, in particular for pocket and wristwatches, with a mechanical escapement which interacts with a mechanical vibration system and which has at least one escapement wheel (1) and an armature (3) as functional elements, characterized in that the escapement functional elements have at least a part of them interacting surfaces are provided with a DLC coating (14). Clockwork according to claim 1, characterized in that the escapement wheel (1) at least at its areas interacting with the armature (3), for example at its escapement wheel teeth (11) interacting with the armature (3) and / or the armature (3) is provided with the DLC coating on its areas interacting with the escapement wheel, for example on its anchor pallets or anchor pins. Clockwork according to claim 1 or 2, characterized in that the armature (3) is made of metal, for example steel, at least at its areas which cooperate with the escapement wheel (1),
wherein, for example, the armature (3) is made in one piece with the regions (9, 10) interacting with the escapement wheel (1); and or
where, for example, the areas interacting with the escapement wheel (1) are anchor pallets (9, 10) or anchor pins. Clockwork according to one of the preceding claims, characterized in that the armature (3) on its area (3 ") interacting with the oscillating system, for example with a balance (5) and / or the part interacting with the armature (3), for example a Driver (8) acting as a lever block are provided with the DLC layer. Clockwork according to one of the preceding claims, characterized in that the shaft (7) of the balance (5) serving as a vibrating system is provided with the DLC coating at least on its areas mounted in the circuit board (12, 13),
where, for example, the bearings for the balance shaft (7) are formed by bearing bores which are provided with the DLC coating at least in the area of the bearing surfaces,
and or
whereby for example the bearing bores are provided in bearing bushes (15 ', 16') which are made of stainless steel or hardenable steel, preferably of plasma nitridable steel (e.g. stainless steel 4301 according to DIN 1.4301) and which are provided with the DLC layer (14) Clockwork according to one of the preceding claims, characterized in that at least some of the gears of the clockwork are provided with the DLC coating at least in the region of the teeth or tooth flanks. Clockwork according to one of the preceding claims, characterized in that the functional elements of the clockwork are each provided with the DLC coating on their entire surface. Clockwork according to one of the preceding claims, characterized in that it has boards (12) and board elements (13) for the storage of functional elements, and that at least one board (12) or a further board element (13) is at least in stock for functional elements of the clockwork forming surfaces are provided with a DLC coating (14),
wherein, for example, the at least one circuit board (12) and the circuit board elements (13) are provided with the DLC coating on their entire surface and this coating also extends, for example, into the bores (15, 16) serving as bearings and completely covers the inner surfaces of these bores , Clockwork according to one of the preceding claims, characterized in that functional elements made of brass are provided on the coated areas with an intermediate layer made of hard metal, for example with an intermediate layer made of chrome,
and or
that functional elements made of steel, preferably stainless steel, are subjected to a heat treatment prior to DLC coating, for example vacuum hardening and / or plasma nitriding, and / or
that at least one bearing of the clockwork consists of a bearing stone, for example made of synthetic ruby, and the counter surface interacting with this bearing, for example the surface of a bearing journal, has the DCL coating,
and or
that at least two interacting and sliding surfaces of the clockwork form a surface of silicon carbide and the second surface is formed by the DCL coating,
and or
that at least one bearing of the clockwork, for example a bearing block forming this bearing, is made of silicon carbide and at least the counter surface interacting with these bearings, for example the surface of a journal, has the DCL coating,
and or
that the elements interacting with an escapement or escape wheel (1) of the clockwork, for example pallets (9, 10), are made of silicon carbide, and that the counter surfaces of the escapement wheel have the DCL coating,
and or
that a lever block or driver of an escapement of the clockwork consists of silicon carbide and the counter surface interacting with this lever block (8), for example an armature (2), has the DCL coating. Clockwork according to one of the preceding claims, characterized in that a spring housing is DLC-coated at least on part of its inner surface. Clockwork, in particular for pocket or wristwatches, with a balance shaft (7) mounted on both sides of a circuit board (12) and / or on a further circuit board element (13), characterized in that the balance shaft (7, 7a) has at least one End is mounted in a bearing (19, 19a) which has a bearing ring (20) and bearing elements (21) arranged in this bearing ring (20) and surrounding the balance shaft (7, 7a), and that the bearing elements (21) consist of silicon carbide or a ceramic, preferably an aluminum oxide ceramic or of artificial rubies,
wherein, for example, the bearing elements (21) are spherical
and or
the balance shaft (7, 7a) is supported in the bearing (19) with a pin end (7 ', 7a') with a reduced cross section
and or
the diameter of the bearing elements (21) is of the order of the diameter of the pin end (7 ', 7a') of the balance shaft (7, 7a),
and or
the balance shaft (7, 7a) is provided, at least at its area in the bearing (19, 19a), with a coating which gives a hard surface, preferably with a DLC coating. Clockwork according to one of the preceding claims, characterized in that the bearing ring (20) and the bearing elements (21) arranged in this ring on the side of the bearing (21) facing away from the balance are covered by a spring (17) against which the balance -Wave rests with its free end,
wherein, for example, the spring (17) is hardened and is provided with the DLC coating or with a ceramic coating at least on its surface forming a system for the balance shaft. Clockwork according to one of the preceding claims, characterized in that the bearing ring (20) is axially preloaded in the direction of the axis of the balance shaft (7a) by at least one spring element (24), so that the bearing ring (20) with the bearing elements (21 ) resiliently against the pin end (7a '),
wherein, for example, the bearing ring (20) is held axially by at least two spring elements (24, 25) and / or the bearing journal (7a) is frustoconical at its journal end (7a ').

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