US2724234A - Bearing for weighted pendulum of self winding watches - Google Patents

Description

Nov. 22, 1955 MEYER 2,724,234

BEARING FOR WEIGHTED PENDULUM OF SELF WINDING WATCHES Filed Sept. 24, 1952 2 Sheets-Sheet l Nov. 22, 1955 M. MEYER 2,724,234

BEARING FOR WEIGHTED PENDULUM OF SELF WINDING WATCHES 2 Sheets-Sheet 2 Filed Sept. 24, 1952 United States Patent- Ofiice 2,724,234 Patented Nov. 22, 1955 BEARING FOR WEIGHTED PENDULUM F SELF WINDING WATCHES Max Meyer, Soleure, Switzerland, assignor to Reamer Watch Co. S. A., fiolenre, Switzerland, a corporation. of Switzerland Application September 24, 1952, Seriai No. 311,257

Claims priority, application Switzerland September 29, 1951 3 Claims. (Cl. 58-82) The object of the present invention is a bearing of a weighted pendulum of a self-winding watch.

In watches of this type it is the established practice to employ a mass or pendulum pivoted to the center of the movement, and capable according to the nature of the watch either of complete rotations in both directions or only of limited angle oscillations between two abutments.

The energy developed by this mass in movement serves to wind the main spring.

The present invention is applicable to such watches, whether of the type in. which the mass makes limited oscillations of a given extent or of the type in which the mass can accomplish complete revolutions, but preferably to those of the latter type.

Admittedly the pivoting of the oscillating mass of a self-winding watch raises very difficult problems, especially in the case of wrist-watches, where the available space is very small.

The mass, disposed eccentrically at the extremity of a lever-arm, subjects its hearings to very great stress, especially when the watch is on the flat, or when it receives shocks perpendicularly to the median plane of its movement.

The ball-bearings, as hitherto made, do much to limit the friction, and have an excellent radial resistance; but a shock to the watch on the fiat is liable, according to the lever-arm, to overstress the ball-bearings dangerously.

The bearing according to the present invention is an improvement, as will be seen, inasmuch as it remedies these drawbacks. It is strong, but at the same time it eliminates the friction just as ball-bearings do.

According to the present invention the bearing is a roller-bearing having two rows reacting inversely on one another, but both placed on the same side of the movement.

The annexed drawing shows three embodiments of the 7 object of the present invention given by way of example.

oscillating mass of the watch shown in the two previous figures; Fig. 4 is a corresponding section showing the second embodiment; Figs. a and 5b show the rollers for use in each of the two preceding embodiments; Fig. 6 is an axial section of the bearings according to the third embodiment; Fig. 7 is a section of the upper half of a ball-cage used in the embodiment shown in Fig. 4; Fig. 8 is a diagram showing how the stress is distributed between the parts of the bearings in accordance with the invention.

Figs. 1 to 3 show that the mass 1 is pivoted to a bearing, whose axis 2 has a pinion 3 geared to two toothed crowns 4 and 5. Each of these crowns has a ratchet 6 and 7 acting on a corresponding ratchet-wheel 8 and 9. These two ratchet-wheels are connected to pinions 10 and 11 geared to toothed wheels 12 and 13, which are themselves geared to one another. Wheel 12 by means of a pinion l4 geared to a wheel 15 drives the shaft 16 of the barrel 17, and so produces the winding of the main spring.

The elements described are supported by bridges 18 and 19.

The details of the mechanism above described do not form part of the present invention. They are well-known contrivances, patented elsewhere, for producing by means of ratchets 6 and 7 a Winding of the main spring of the barrel 17, always in the same direction, independently of the sense of rotation of the mass 1.

The following is the solution of the problem of the pivoting of the mass according to one embodiment of the invention.

The references accompanying the following specification have not all been reproduced in Fig. 1, in order to avoid unnecessary detail in the drawing. It is quite clear that Fig. 3 is only an enlargement of part of Fig. l, and that it is sutficient to explain the present description of the first embodiment.

The mass is therefore shown as 1, especially at the extremity (which does not appear in Fig. l) of its arm 1. We have seen how it winds the main spring by its rotation around axis 2.

Shaft 2 has two opposite roller races, one exterior 20 and the other interior 21, between which there is a crown 22 fixed at bridge 18, having itself two roller races opposite to the above two.

Between each of the roller races 21 and 21 and the corresponding face of the crown 22 there are conical rollers 23 and 24, the geometrical axes of which are inclined in relation to the geometrical axis of the shaft 2 in such a way that the axes of the bearings describe two cones with opposite apexes.

Thanks to this arrangement, and to the fact that the apexes of the cones formed by the said rollers also come across the axis of the shaft 2, the rollers roll in their courses without the least sliding.

In the example shown in the drawing the height of the pivoting shown is so low that the cones described by the axes of the rollers interpenetrate (see the dot-and-dash lines).

It will readily be perceived that the mechanical action of the parts of bearings of this kind will be much weaker in case of shocks, if the mass hangs than if it is fiat, in-

spite of the wedging eifect of the rollers, and further that with a flat disposed mass the action will still be much less than with the usual bearings.

Figs. 5a and 512 show in detail how the rollers can be constituted.

Although Fig. 3 does not show the rollers as detached from one another, an arrangement which yields excellent results, the second case shown in Fig. 4 illustrates how a staggered disposition is possible with (as will be seen below) an even better distribution of stresses.

This second illustration shows roller bearings 25 and 26 which are kept in quincunx by a ball-cage 27.

Again, in the second embodiment of Fig. 4 the bearing is mounted in a way different from that of the first embodiment. In the first embodiment the parts were forced onto the shaft 2, so as to form part of it. in the second embodiment on the other hand, while the int rior roller race 23 is part of the shaft as in the first embodiment, the exterior roller race 29 is held on a square-shaped part 30 by means of a screw 31.

Fig. 8 shows in diagrammatic form how rollers or balls in the staggered arrangement described receive the stress of the mass in the watch on the fiat. It is supposed that each row should consist of five rollers or balls, represented by black lines for the upper row and dotted lines for the lower row.

With the watch fiat in the plane of the drawing and the mass bearing on the extremity of arm 32, there will be a pressure on the left half on the two shaded rollers of the upper row and on the right half on the two shaded rollers of the under row. The stress will accordingly be distributed symmetrically as between each side of the axis AB on two=fifths of the rollers or balls.

If the direction of arm 32 was 32, the distribution would be on three-fifths.

But in any case the distribution remains symmetrical, with a symmetrical axis always passing through the axis of rotation of the shaft supporting the mass, and with stresses acting always at the greatest possible distance from the axis of rotation of the shaft, i. e. in the best possible conditions.

The position is quite different with the usual system of pivoting with a single row of balls. We may imagine how this would be, if we eliminated the balls of the lower row in the diagram in Fig. 8.

We should then have two of these balls loaded in the left part of the line AB, and three in the right part,

with the result that the symmetry axis would no longer pass through the axis of the pivoting shaft.

The symmetrical distribution of the stress and the increase in the number of rollers, as also the relative distance of their emplacement from the center, ensure the utmost possible durability of the bearings under the present invention.

As stated, the conical rollers having an angle of 15 to 16 roll without, or almost without, friction owing to the fact that their exterior extremity, whether conical (as in Fig. 5a) or spherical (as in Fig. 5b), does not touch the edge of the races (e. g. at 22) except along a line so as to suck up lubricant.

The ball-cage 27 according to the second embodiment shown in Fig. 4 should preferably consist of two parts identical with the half-section shown in Fig. 7. It is a pressed iron ring with notches 33 for the rollers, separated by teeth 34, while the opposite side has teeth 35 which fit into similar teeth in the other half, shown in part in dot-and-dash lines.

The third embodiment illustrated in Fig. 6 is on the same lines as the other two, but has two rows of balls 36 and 37 rolling between the exterior and interior ball races 38 and 39 and those of the intermediary crown 40.

These ball races are so placed that, as in the case of the conical rollers, the pressure on the balls is in a direction xy at an acute angle to the shaft 41 of the bearlugs.

In view of the ample means of lubricating this last type of ball-bearings, their friction is practically nil, and the whole arrangement is much more solid and economical than ordinary ball-bearing systems with V-shaped ball races having four points of contact for each ball.

The stress involved is thus very slight, so that the construction of such bearings does not call for an exaggerated degree of precision.

What I claim is:

1. In a self-winding watch having an oscillatable mass for Winding the main spring; a mounting for the oscillatable mass comprising a shaft extending axially at one side of the mass, fixed support means extending around said shaft and including annular race defining means thereon, two closely adjacent rows of conical rolling bodies at opposite sides of said race defining means and supporting said shaft on said race defining means with the axes of rotation of the rolling bodies in each of said rows generating a conical surface having an obtusely angled apex disposed on the axis of said shaft and with the conical surfaces generated by the axes of rotation of the rolling bodies in said two rows intersecting and enclosing substantially the same obtuse angle at the apices thereof, and a spacer cage means maintaining the rolling bodies in each of said rows in circumferentially spaced apart and staggered relationship with respect to the rolling bodies in the other of said rows.

2. In a self-winding watch having an oscillatable mass for winding the main spring; a mounting according to claim 1, wherein said rolling bodies are frusto-conical.

3. In a self-winding watch having an oscillatable mass for winding the main spring; a mounting according to claim 1, wherein each of said rows includes an odd number of at least five of said rolling bodies.

References Cited in the file of this patent UNITED STATES PATENTS 767,025 Volker Aug. 9, 1904 1,397,142 Palmgren Nov. 15, 1921 1,701,474 Harris Feb. 5, 1929 2,004,013 Reed June 4, 1935 2,491,005 Green Dec. 13, 1949 FOREIGN PATE TS 147,711 Austria Nov. 10, 1936 247,037 Switzerland Nov. 1, 1947 271,422 Switzerland Ian. 16, 1951

Images