US3481137A

US3481137A - Electronic timepiece

Info

Publication number: US3481137A
Application number: US578535A
Authority: US
Inventors: Max Dipl Ing Hetzel; Henri Robert; Heinrich Haering
Original assignee: Centre Electronique Horloger SA
Current assignee: Centre Electronique Horloger SA
Priority date: 1965-09-13
Filing date: 1966-09-12
Publication date: 1969-12-02
Anticipated expiration: 1986-12-02
Also published as: FR1502783A; CH1267865A4

Description

Dec. 2, 1969 M. HETZEL ETAL ELECTRONIC TIMEPIEGE 5 Sheets-Sheet 1 Filed Sept. 12, 1966 Dec. 2, 1969 M. HETZEL ETAL 3,481,137

' ELECTRONIC TIMEPIECE Filed Sept. 12, 1966 5 Sheets-Sheet 2 De 1969 M. HETZEL ETAL ELECTRONIC TIMEPIECE 5 Sheets-Sheet 3 Filed Sept. 12, 1966 Dec. 2, 1969 M. HETZEL. ETAL ELECTRONIC TIMEPIECE 5 Sheets-Sheet 4 Filed Sept. 12, 1966 mm mm mm 2 whim D 1969 M. HETZEL ETAL 3,

ELECTRONIC TIMEPIECE Filed Sept. 12, 1966 5 Sheets-Sheet 5 3,481,137 ELECTRONIC TIMEPIECE Max Hetzel, Bienne, Henri Haring, Tavannes, and Henri Robert, Chaux-de-Fonds, Switzerland, assignors to Centre Electronique Horloger S.A., Neuchatel, Switzerland Filed Sept. 12, 1966, Ser. No. 578,535 Claims priority, application Switzerland, Sept. 13, 1965, 12,678/ 65 Int. Cl. G04c 3/00 US. Cl. 5823 7 Claims ABSTRACT OF THE DISCLOSURE In an electronic timepiece including a base plate independently carrying both a movement cage and the foot of a resonator which is electrically maintained, wherein the resonator constitutes the time base and the driving member for the movement, there is provided a bearing cage independent from the movement cage and connected rigidly to the foot and including a ratched wheel; and a pawl for transmitting motions of the resonator to the ratchet wheel, whereby the bearing cage, the movement cage and the resonator can be independently and separately assembled and disassembled.

In electronic timepieces employing an electro-mechanical oscillator as a time base and driving member, the transformation of the oscillating movement into a rotating movement for driving the clockwork is etfected generally by means of a ratchet device comprising a driving pawl rigid with the resonator, acting on a first ratchet wheel, and a stop pawl, secured on the plate of the move ment, immobilizing the ratchet wheel when the same is not driven by the reasonator.

The ratchet wheel is pivoted in the plate as are the other mobiles of the movement. The resonator, the pawls and the ratchet wheel constitute a driving assembly the members of which must be adjusted one to the other in a very precise manner. However, such an adjustment is very diflicult under practical conditions when the resonator is made separately with its driving pawl, then mounted on the plate bearing the ratchet wheel and the stop pawl. It has been noted furthermore that the plate often has a certain flexibility so that the stop pawl can more sufiiciently with respect to the driving pawl so as no longer be correctly in phase with the driving pawl.

The present invention has for object an electronic timepiece the time base of which and the driving member of which consist of a reasonator electrically upkept and driving the movement by means of a pawl driving a ratchet wheel, which timepiece does not have the drawbacks above-mentioned. It is characterised mainly by the fact that the ratchet wheel is mounted in a bearing cage which is independent of the movement cage which is secured on the resonator itself.

The bearing cage can be secured by its upper bridge on the foot of the resonator. The cage can be made independently of the resonator, however because of its cantilever position on the resonator, there is the danger of having the upper bridge bend and with it the cage would move vertically.

This can be avoided by suitable assembly.

According to another characteristic of the invention, the independent cage has two bridges secured respectively on the upper and lower faces of the foot of the resonator securing the resonator to the plate.

This arrangement is made practically possible thanks to the great precision which can be obtained by the current milling processes for shaping the thickness of the resonator.

United States Patent The annexed drawing represents by way of example two embodiments of the object of the invention as well as modifications.

FIGURE 1 shows a partial view of an electronic watch provided with a double mechanical pawl arrangement.

FIGURE 2 shows a partial vertical cross-section taken along the line I-I of the watch of FIGURE 1.

FIGURES 2A and 2B are cross-sectional views taken along lines 2A2A and 2B2B, respectively.

FIGURE 3 shows a similiar assembly but provided with a clique combined with a magnetic gear.

FIGURE 4 shows a partial vertical cross-section of the age and of the foot of the resonator.

FIGURES 5 and 6 show a cross-section and a plan view of a modified form of a magnetic gear. I

FIGURE 7 shows cross-sectionally a second modification of the pivoting of the magnetic gear.

The electronic watch shown on FIGURES 1 and 2, and 2A and 2B comprises essentially a resonator 1 having two bent branches maintained electromagnetically. This resonator is secured by its V-shaped foot 1a by means of three screws 2, 3 and 4 on the plate 5 of the movement. On one of the branches of the resonator is secured a driving pawl 6. A first ratchet wheel 18 is mounted in a cage independent of the movement cage and formed by the upper and lower bridges 7 and 8 respectively, linked therebetween by a screw 9 and two

positioning pins

10 and 11. The bearing cage is secured to the resonators foot 1a by its upper bridge 7 by means of two screws 13 and 14. The reasonator and the cage thus form a unit which can be made independently of the rest of the watch. In the cage is mounted additionally a lever 15 pivoted in this cage at 16 and bearing at is extremity 15a the stop pawl 17. This lever permits to adjust the phase of the stop pawl with respect to that of the driving pawl 6. The mobiles are formed in the order given by a first ratchet wheel 18 mounted on a shaft of a five toothed cam 19 periodically driving the arm 20 of a lozange shaped lever 21 at the extremity 21a of which is encased a pawl 22 driving a second ratchet wheel 23 the coaxial pinion 24 of which drives the second wheel 25, the first mobile of the gear train which is pivoted on the plate of the movement. This double pawl acts as a mechanical frequency filter between the resonator and the movement. The fact that the point of attack pawl 22 on the ratchet wheel 23 is located on the other side of the perpendicular joining the shaft of the lever 21 to that of ratchet wheel 23 by the point where it is encased in lever 21 permits to obtain a simple construction which does not require an auxiliary return spring for lever 21.

In a preferred embodiment, the oscillating resonator has a frequency of 480 cycles per second. By giving wheel 18, 240 teeth and cam 19 five teeth, it is seen that wheel 18 will make 2 turns per second and that each tenth of a second, lever 20 will make one oscillation. The second ratchet wheel 23 has teeth.

In the second embodiment shown on FIGURE 3, the cage of the device consists also of bridges 7 and 8 mutually connected by screw 9 and the two

positioning pins

10 and 11, the cage being secured by its upper bridge 7 to the foot 1a of the resonator by two screws 13 and 14. This cage is smaller than the previous one owing to the Jse of a simpler device. In this device, there is again the first ratchet wheel 18 driven by pawl 6 and held back by stop pawl 17, but rigid this time with a magnetised polar wheel 26 driving magnetically a second polar wheel 27 of greater diameter and the coaxial pinion of which 28 drives an intermediate Wheel 29 the pinion of which 30 meshes with the second wheel 25. The advantage of the magnetic gear in this particular case consists essentially in that the space separating the poles of wheels 26 and 27 can vary by several hundredths of a millimeter without 3 affecting the proper functioning of the watch, which permits to mount wheel 27 on the plate of the movement while the polar wheel 26 is mounted in the cage. The use of an independent cage for the ratchet and pawl device rigid with the resonator has in this embodiment certain evident advantages, the link between the two units formed on the one hand by the resonator and by its ratchet and pawl device and on the other hand by the movement, have a flexibility which is not present in the first embodiment and which permits a rapid and easy assembly of these two units.

In the embodiment shown in FIGURE 4, the cage is no longer cantilever on the resonator but is integral with the foot of the resonator.

In FIGURE 4 there is shown by 31a the securing foot of the resonator on plate 32 of the watch as shown .on FIGURE 1. The foot of the resonator secured to plate 32 of the movement by three triangularly disposed screws two of which 33 and 34 can be seen in the drawing. The cage is composed of an upper bridge 35 and of a lower bridge 36 linked together by a screw 37 freely passing through the foot of resonator 31a and positioned by

pins

38 and 39. This arrangement not only simplifies the assembly, the number of screws and the assembling elements being reduced to a minimum, but increases the precision of positioning of the mobiles with respect to the bridge. Furthermore, the fact of placing the head of screw 37 on the side of the lower bridge makes it impossible to take the cage apart without previously removing the assembly of the resonator and cage from the plate.

The ratchet wheel 40 driven by the resonator pawl is riveted between the upper bridge and the lower bridge of the cage and there instead of a pinion a polar magnetised wheel 41 of small diameter magnetically drives magnetic wheel 42 the pinion of which 43 meshes with an intermediate wheel 44 driving in its turn the dial train not shown. For reasons of assembly, in particular for cleanliness and handling, it is advantageous to lodge the magnetic wheel 42 in the cage and not under the bridge of the gear train. The upper pivot 44' of the magnetic wheel turns in a bearing of the upper bridge 35 while its lower pivot 45 turns in a bearing mounted in plate 32. The lower pivoting of the magnetic wheel and of its pinion and the lower pivoting of the intermediate wheel 44 are thus located in the same constructional element 32 so that pinion 43 will engage correctly with intermediate wheel 44.

The lower pivot shank 46 of the magnetic wheel passes through the lower bridge 36 with a small axial and radial play. During the taking apart of the resonator with the cage, the magnetic Wheel 42 remains rigid of the cage borne by the shoulder of the shaft and its upper pivot does not leave its bearing. Means are provided, for example, a stud 53 which locates the lower bridge member 36 with respect to base plate 32 before the lower pivot enters its bearing.

This arrangement reduces to the strict minimum the size of the lower bridge 36 of the cage and facilitates the fitting of the resonator bearing the cage on the base plate 32, without damaging the teeth of the first intermediate ard construction elements in particular settings. It is also possible to pivot the magnetic wheel 42 between the upper bridge and the lower bridge of the cage. In this case it is not however possible to use stones having standard dimensions, for during the placing of the resonator with the cage in the re-assembled plate, there is danger during the vertical movement of the assembly to hit and damage the teeth of the intermediate wheel 44.

FIGURES 5 and 6 show a modification fulfilling the required conditions. In this

construction stones

47 and 48 of the lower hearing are cut by a vertical plane in such a way that the edge of these stones pass at a certain distance from the Wheel 44 during the placing of the resonator with the cage in the timepiece. The

stones

47 and 48 are lodged in the lower bridge 36 and in a plate 49, the vertical surfaces of these stones being aligned with the edge of bridge 36.

In a second modification shown on FIGURE 7, there is used a single small size stone 50 aligned with the edge Slof bridge 36 or the stone may be separated from the edge by a very thin wall.

What is claimed is:

1. In an electronic timepiece including a base plate independently carrying both a-movement cage and the foot of a resonator which is electrically maintained, said resonator constituting the time base and the driving member for said movement, a bearing cage independent from said movement and connected rigidly to said foot, said hearing cage including a ratchet wheel, and a pawl for transmitting motion from said resonator to said ratchet wheel.

2. A timepiece as claimed in claim 1 comprising a cam rotatable with said ratchet wheel, and an oscillatory system driven by said cam and driving a second ratchet wheel geared to said movement.

3. A timepiece as claimed in claim 1 and comprising a magnetiSed polar wheel driven by said ratchet wheel and driving magnetically a second polar wheel which is mechanically free of said first polar wheel and which in turn drives said movement.

4. A timepiece as claimed in claim 3 wherein said second polar wheel has a spindle and the end of the spindle is journalled in said bearing cage and the other end of said spindle is journalled in said base plate.

5. Timepiece according to claim 1, wherein said bearing cage consists of a lower and an upper bridge, said lower bridge being located above the plate of the movement and the ratchet wheel being pivoted between said bridges.

6. Timepiece according to claim 5, wherein said lower bridge of said bearing cage is secured to said upper bridge.

7. Timepiece according to claim 1, wherein said bearing cage comprises two bridges secured against the upper and lower surfaces of the foot securing the resonator to the plate.

References Cited UNITED STATES PATENTS 2,625,004 1/1953 Bush et al. 58-23 2,700,272 1/1955 Trichel 5856 FOREIGN PATENTS 769,614 3/1957 Great Britain.

RICHARD B. WILKINSON, Primary Examiner E. C. SIMMONS, Assistant Examiner