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Publication numberUS3077728 A
Publication typeGrant
Publication dateFeb 19, 1963
Filing dateSep 29, 1960
Priority dateSep 30, 1959
Publication numberUS 3077728 A, US 3077728A, US-A-3077728, US3077728 A, US3077728A
InventorsHeinrich Stamm
Original AssigneeEbauchesfabrik Eta Ag
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Escapement lever for watches, timepieces and the like
US 3077728 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Feb. 19, 1963 H. STAMM 3,077,728

ESCAPEMENT LEVER FOR WATCHES, TIMEPIECES AND THE LIKE Filed Sept. 29. 1960 7 871'Tob 8 9 8 771 rid/1 5721mm United fitates Patent" 9 3,077,728 ESCAPEMENT LEVER FOR WATCHES, TIME- PIECES AND THE LIKE Heinrich Starnrn, Granges, Switzerland, assignor to ETA AJG. Eloauches-Fabrik, Granges, Switzerland, 2 joint stock company Filed Sept. 29, 1960, Ser. No. 59,242 Qlainis priority, application Switzerland Sept. 30, 1959 3 Claims. (Cl. 58-121) This invention relates to escapement levers for watches, timepieces and the like, and in particular to a fixing arrangement of the safety fingers of such levers.

The escapement levers known in the art and used in the best watches are usually provided with a heavy portion at the end of their forked arm. This heavy portion is extending below the lever arm and a bore is provided therein in a direction parallel to the arm carrying said portion to serve as lodging for the safety pin or finger.

The lever portion carrying the safety finger substantially increases, however, the moment of inertia of the lever and it also causes the latter to be considerably out of poise.

Since an escapement lever disturbs the running rate of the watch the more the greater its moment of inertia is, an escapement lever as for commoner watches provided with a safety pin merely riveted to a thin lever plate and then bent at right angle below said plate appears to be better in this respect than the escapement levers of the best watches, because it is substantially lighter and better in poise.

it is therefore an object of this invention to provide a fixing arrangement for a substantially cylindrical safety pin or finger of an escapement lever, which enables a substantial reduction of the weight and of the moment of inertia of the lever, while ensuring an absolutely reliable fixation and adjusting possibilities of the length of the safety pin or finger as good as with the known escapement levers of the same type.

Another object of the invention is to provide the forked lever arm with at least a pair of upright projections extending from its lower face underneath the forked end forming the horns of the lever, so as to enable resiliently clamping a substantially cylindrical safety pin or finger between said projections.

Still further objects of the invention will become apparent in the course of the following description.

One embodiment of the escapement lever according to the invention is represented by way of example in the drawings annexed to this specification.

In the drawings:

FIG. 1 is an elevational view of said embodiment;

FIG. 2 is a view from the bottom of the lever of FIG. 1, and

FIG. 3 is a part elevational view in the direction of arrow III in FIG. 1.

With reference to the drawings the escapement lever 1 is rigidly fixed to a usual staff 2 and it comprises an arm 3 slendered towards the forked lever end forming the horns t so as to reduce the weight and above all the moment of inertia of the lever part considered.

The slendered lever arm 3 is obtained by milling as at 5 the lower face of said arm. The milled portion 5 does however not extend to the end of arm 3. It leaves a heavy portion at said arm end, which is extending below the lever horns. A transverse slot 6 is provided across said heavy portion so as to form two projecting wall "ice portions below the lever arm and a channel 7 (FIG. 3) is provided in a direction parallel to arm 3 across said wall portions so as to form two pairs of projections 8.

The width of channel 7 is a trifle smaller than the diameter of the cylindrical safety pin of finger 9 so that the latter may be set between projections 8 while urging the latter away from one another and producing a resident deformation thereof. The projections 8 thus firmly grip the safety pin 9 so that the latter cannot move by itself with respect to the lever. The projections 8 are very light and they do not substantially increase the moment of inertia of the lever. Their length can even be reduced to such an extent that the ends of these projections are flush with the safety pin.

The weight of the lever is already substantially reduced even without providing slot 6 across the heavy portion of the forked lever arm and when the latter is accordingly provided with only one pair of safety pin clamping projections.

With respect to the fixing arrangements of the safety pin, which are known in the art, the arrangement described has still the advantage to permit using a safety pin with a diameter substantially smaller than that of the usual cylindrical safety pins set with force fit into a bore of a bulky lever portion, since it is indeed easier to provide a very narrow slot or channel as 7 than to provide a small cylindrical bore. This possibility of using a safety pin smaller than with known levers of the same type has again the advantage to permit reducing the moment of inertia of the lever.

Since the lever according to the invention clamps the safety pin at two different points being relatively far away from one another, it will be observed that the safety pin is held in a more precise position than with levers holding said safety pin between two parallel and relatively long surface portions.

While one embodiment of the invention has been described in detail with reference to the drawings, various changes in the shape, sizes and arrangement of parts will appear obvious to those skilled in the art.

I claim:

1. In an escapement lever comprising an arm carrying two horns and a safety finger on said arm, a safety finger fixing arrangement comprising upright projections on said arm near said horns thereof to clamp said safety finger resiliently, said safety finger being cylindrical and said projections having a length substantially equal to the diameter of said safety finger.

2. In an escapement lever comprising an arm carrying two horns and a safety finger on said arm, a safety finger fixing arrangement comprising two pairs of upright projections on said arm near said horns thereof to clamp said safety finger resiliently in two points longitudinally spaced apart along said finger.

3. The fixing arrangement of claim 2, said projections being flush with said safety finger.

References Cited in the file of this patent UNITED STATES PATENTS 1,327,226 De Long Jan. 6, 1920 2,964,901 Beyner et al Dec. 20, 1960 2,971,324 Beyner Feb. 14, 1961 FOREIGN PATENTS 3,730 Great Britain Dec. 8, 1868

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1327226 *Jul 13, 1916Jan 6, 1920De Long Charles EWatch-escapement
US2964901 *Feb 3, 1959Dec 20, 1960Ebauches SaLever escapement for timepieces
US2971324 *Jan 28, 1958Feb 14, 1961Ebauches SaLever escapement for timepieces
GB186803730A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4375382 *Sep 3, 1981Mar 1, 1983Wallace Computer Services, Inc.Method of making a continuous web form and product, particularly one suitable for airline ticketing
US9015921Aug 8, 2012Apr 28, 2015Nivarox-Far S.A.Metal pallets with polymer horns
EP2557460A1 *Aug 12, 2011Feb 13, 2013Nivarox-FAR S.A.Metallic pallets with polymer horns
EP2557461A1 *Jul 3, 2012Feb 13, 2013Nivarox-FAR S.A.Metal anchor with polymer horns
U.S. Classification368/125, 968/102
International ClassificationG04B15/14, G04B15/00
Cooperative ClassificationG04B15/14
European ClassificationG04B15/14