US2807133A

US2807133A - Self winding time-piece

Info

Publication number: US2807133A
Application number: US471455A
Authority: US
Inventors: Maire Georges
Original assignee: Tavannes Watch Co SA
Current assignee: Tavannes Watch Co SA
Priority date: 1953-11-28
Filing date: 1954-11-26
Publication date: 1957-09-24
Anticipated expiration: 1974-09-24

Description

Sept. 24, 1957 G, MMRE SELF WINDING TIME-PIECE 2 Sheets-Sheet .1

Filed Nov. 26, 1954 Sept. 24, 1957 s. MAIRE SELF WINDING TIME-PIECE 2 Sheetsiheet 2 Filed Nev. 26, 1954 United States Patent C) SELF WINDING TIME-PIECE Georges Maire, Tavannes, Switzerland, assgnor to Tavannes Watch Co. S. A., Tavannes, Switzerland, a firm of Switzerland Application November 26, 1954, Serial No. 471,455

Claims priority, application Switzerland November 28, 1953 1 claim. (Cl. ss-sz) The present invention relates to a self-winding timepiece with an oscillating weight pivotally secured at the center of the watch movement, said weight carrying a cam actuating at least one oscillating lever provided with a winding pawl. Itis an object of the invention to provide a novel and efficient automatic winding mechanism for self-winding watches.

A further object of the invention is to provide a selfwinding mechanism of solid and precise construction whereby most of the rotation of the oscillating weight is utilized for winding up the time-piece.

According to the invention, the winding weight drives a cam, shaped as a counter-heart piece and cooperating with two levers, whereby the oscillating movement of the levers is used to actuate a wheel connected to the winding mechanism.

These and other features and advantages of the novel winding mechanism, according to the present invention, will appear from the following description and claim in conjunction with the accompanying drawings, which illustrates by way of example an embodiment of the invention.

In the drawing:

Fig. 1 is a plan view of a time-piece, said gure including only those parts that are necessary for understanding the invention.

Fig. 2 is a cross section, on an enlarged scale through II-II of Fig. 1.

Fig. 3 is a plan view of a modification of said time-piece.

Fig. 4 is a cross section on an'enlarged scale through line IV-IV of Fig. 3.

Fig. 5 is a plan view of a further modification of said time-piece.

In Figs. l and 2, the rotary winding weight is designated by 1, it is pivotally secured and freely rotatable on a central pin 2 provided with a collar 2a. By means of this collar the pin 3 is fixed to a plate 3 and it is supported by two bearings 4 and 5 inserted in the frame-work of the automatic Winder.

The frame-work comprises a bridge 6, in a sleeve 6a of which is mounted the bearing 4 and a circular plate 7 centrally adjusted between two shoulders 6b of the bridge 6, one only being represented. The plate is fixed in its place by one screw 9 engaged in each shoulder. The bearing 5 is tixed by the plate 7 carrying a stud 7a that fits into the opening of a key 8 securing axially pin 2.

The plate 3 of the oscillating weight has a protruding portion 3a, the periphery of which constitutes a cam generally shaped as a counter heart, cooperating with two rollers 10, each pivotally fixed to an oscillating lever 11. Each ofthe levers 11 is pivotally mounted by means of a screw 12 secured to the frame-work of the automatic Winder. Each of these levers is submitted to the action of a spring 13, holding the rollers in contact with the cam 3a. Thus an angularly shifting of the weight 1 causes an oscillating movement of the levers 11.

A pawl 15 is pivotally fixed by a screw 14 to each lever 11. The leading edge of the pawl cooperates with a wheel 16 of the winding-up gear and it is held in contactwith the wheel 16, the pawl being submitted to the 2,807,133 Patented Sept. 24, 1957 ICC action of a spring 17. The wheel 16 is freely rotatable about the circular plate 7, serving as a support; furthermore it meshes with a wheel 18, rigid with a pinion 19, driving the ratchet wheel of the spring box, partially illustrated on Fig. 2 and designated by 40.

The angular shifting of levers 11 produces through the agency of the pawls 15 a rotation of the wheel 16 as indicated by the arrow 20, Fig. l. The edges 15a of the pawls 15 have a double tooth in order to decrease the idle-path ofthe same by meshing.

In the modification illustrated in Figs. 3 and 4, the oscillating weight 21, rigid with a plate 21a, is also pivotally secured to the center of the watch movement. This weight 21 carries a ring 22 the internal periphery of which has the shape of a counter heart piece, and two rollers 23 each driven by an oscillating lever 24 are held by the action of lsprings 25 in Contact with the counter heart piece 22. A pawl 26 is carried by each lever 24 and by the action of a spring 27 it is urged against a wheel 28 of the winding-up gear, pivotally fixed to the center of the watch movement. The rotation of the weight promotes, by the action of the ring 22 on the rollers 23, an oscillating movement of the levers 24 so that the pawls 26 drive the wheel 28.

In the modification illustrated in Fig. 5, the plate 29 of the oscillating weight 30 is rigid with a central cam 29a: identical to the cam 3a in Figs. 1 and 2. The cam 29a actuates two rollers 31 each carried by an oscillating lever 32 linked by a screw 33 to the frame-work of the automatic Winder and submitted to the action of the spring 34 holding the rollers 31 in contact with the cam 29a. Each lever 32 carries a pawl 35 urged, by means of a spring 36, against a ratchet wheel 37, coaxial with the screw 33. The ratchet wheels 37 are rigid with pinions 38 meshing with a wheel 39 pivotally fixed at the center of the movement, coaxially with the weight 30, and belonging to the winding-up gear, the other parts of which are not shown.

As will be apparent from the above description, an advantage of the winding mechanism of the present invention forms the fact that the movement of both levers is such as to convert, with the smallest possible losses, the shifting of the oscillating weight in an uni-directional rotary movement of the central wheel of the winding-up gear. This advantage is particularly suitable for the construction of automatic watches flat and of reduced size.

What I claim is:

In a self-winding watch, the combination of a case, a frame in said case, a winding weight revolubly mounted to move around the axis of the watch case, a cam rigid with said weight, two duplicate levers pivoted around points of the frame diametrically opposed with reference to the axis of the watch and at equal distances therefrom, said levers being lsymmetrical of each other with reference to said axis, springs urging said levers into engagement with said cam, a ratchet wheel coaxial with the watch, a pawl pivotally secured to each lever, said pawls being diametrically opposed and symmetrical of each other with respect to the watch axis and engaging the ratchet wheel to drive the latter in a predetermined direction each time the corresponding lever is shifted in a given radial direction under the opposed actions of the cam and of the spring cooperating with said lever, and a winding up gear controlled by the progression of the ratchet wheel in the said predetermined direction.

References Cited in the tile of this patent FOREIGN PATENTS 254,851 Switzerland Ian. 3, 1949 268,215 Switzerland 4 Aug. l, 1950 284,841 Switzerland Dec. 1, 1952