US2567567A

US2567567A - Hairspring for timepieces

Info

Publication number: US2567567A
Application number: US18880A
Authority: US
Inventors: Kohlhagen Walter
Original assignee: INGRAHAM E CO
Current assignee: E INGRAHAM Co; INGRAHAM E CO
Priority date: 1948-04-05
Filing date: 1948-04-05
Publication date: 1951-09-11
Anticipated expiration: 1968-09-11

Description

Sept. 11, 1951 w. KOHLHAGEN HAIRSPRING FOR TIMEPIECES Filed April 5, 1948 Patented Sept. 11, 1951 HAIRSPKING FOR TIMEPIECES Walter Kohlhagen, Elgin, Ill., assignor to The Ingraham Company, Bristol, 001111., a corporation of Connecticut Application April 5, 1948, Serial No. 18,880

3 Claims. (01. 58-115) The present invention relates to improvements in hairsprings and relates more particularly to improvements in hairsprings for clocks, watches and other timepieces.

It is the general practice to secure the inner end of a spiral hairspring to a unit comprising a balance-staff and a balance-wheel on the latter and then prior to the assembly of the unit into a timepiece, vibrating the assembly until the same oscillates at approximately the predetermined desired rate, whereupon the outer convolution of the hairspring is provided with a kink located adjacent its end and designed to be seated against an anchoring-abutment which usually takes the form of an apertured anchoring-stud.

In assembling hairsprings of the type above referred to in a clock movement for instance, the outer end of the hairspring is manually maneuvered through an aperture in a regulatinglever and then through an aperture in an anchoring-stud. This procedure requires careful handwork and hence is expensive.

Furthermore, since it is the general practice to anchor the outer end of such hairsprings in an aperture in an anchoring-stud by means of a wedge, the indiscriminate kinks commonly applied in such hairsprings are apt to be unduly straightened out in the process of driving the wedge in place. This latter effect results in distortion of the hairspring and erratic behaviour of the timepiece in which it is installed.

One of the main objects of the present invention is to provide a superior hairspring having a terminal-end which will not materially interfere with its threading through an aperture in a regulating-lever or in an anchoring-stud.

Another object of the present invention is to provide a hairspring having a superior terminalend so shaped as to substantially thread itself through apertures in a regulating-lever or ananchoring-stud when the balance-unit of which it may form a part is rotated in the direction required to move its said outer end toward such apertures.

A further object of the present invention is to provide a superior hairspring 01' the character referred to having an outer terminal-end which not only will not materially interfere with its entry into apertures of the character referred to but which will also minimize the distortion of the hairspring when its said terminal-end is anchored in an anchoring-stud or the like.

With the above and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all 2 features in the said disclosure which are novel over the prior art.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a perspective View of a hairspring embodying the present invention and shown as attached at its inner end to a hairspring-collet;

Fig. 2 is a broken face view of a movementframe of a clock showing the hairspring constructed in accordance with the present invention as mounted therein, together with a bah ance-stafl, balance-wheel, bearings and regulator;

Fig. 3 is an edge view thereof;

Fig. 4 is a broken detail sectional view taken on line 4-4 of Fig. '3 but on a larger scale;

Fig. 5 is a broken view on a still larger scale of the outer portion of the hairspring shown in conjunction with the anchoring-stud and wedgelike retaining-pin, the anchoring-stud being shown in section and the retaining-pin being shown as partly inserted into the aperture in the said anchoring-stud; and

Fig. 6 is a. perspective view of the regulatinglever, detached.

The hairspring illustrated in the accompanying drawings is of spiral form and is generally designated bythe reference character [0. The outer portion of the said hairspring adjacent its extreme end. is bent substantially radially inwardly to form a stop-reach H and then is bent again in the general direction of the curvature of the hairspring to form a terminal-reach l 2. The respective reaches H and I2 are integral with the hairspring proper It] and the terminal-reach I2 is inclined outwardly from the inner end. of the stop-reach ll so that its extreme end occupies the position which is substantially the same radial distance from the center of the hairspring as is the point of juncture of the stop-reach H with the hairspring proper of which it forms a part.

The inner end of the hairspring I0 is clamped in a collet 13 which, in turn, is tightly fitted upon a balance-staff [4 which, like the collet 13, may be of any approved construction. The balancestafi' M has mounted thereon a balance-wheel l5, in a manner usual in so-called marine type escapement mechanisms.

The respective opposite ends of the balancestafi M are of conicalform and the endv adjacent the hairspring I0 is adapted to oscillate in a bearing-stud I5, while the end of the balancestafl nearest the balance-wheel i'5'is' adapted to oscillate in a bearing-stud H, as is indicated in Fig. 3.

The bearing-stud I6 is mounted in a movement-plate l8 and in a similar manner the bearing-stud I1 is mounted in a companion movemerit-plate l9 between which the unit comprising the parts to [5 inclusive, is adapted to oscillate. The said movement-plates l8 and iii are held in spaced relationship with respect to each other by a suitable number of pillars such as 20.

Mounted for turning movement against the outer face of the movement-plate l8 and about the bearing-stud I6 as a center, is a regulatinglever generally designated by the reference character 2|. The said regulating-lever is formed with an aperture 22 through which the outer convolution of the hairspring is adapted to pass.-

The width of the aperture 22 is in excess of the length in a radial direction) of the stop-reach l l of the said hairspring so as to freely permit the kinked end of the latter to be passed therethrough. 1

Mounted in the movement-plate I8 is a substantially -T-shaped anchoring-stud or -member 23 having its leg or stem extending through the said movement-plate inwardly toward the balance-wheel IS. The said anchoring-stud is rigid- 1y attached to the movement-plate 18 in a suitable manner such, for instance, as by staking the same at 24, as is indicated in Fig. 3. e

The anchoring-stud 23 above referred to is formed with an aperture 25v which, like the aperture 22 before referred to, is in circumferential alignment with the free end of the hairspring it. The width of the said aperture 25, in a direction radially of the balance-wheel l5 and associated parts, is slightly in excess of the length of the stop-reach ll of the hairspring so as to freely permit the kinked end of the latter to be passed therethrough.

By reference to Figs. 1 and 5 in particular, it will be noted that the extreme end or tip of the inclined terminal-reach 12 of the hairspring i0 is substantially the same radial distance from the center of the balance-staff M as is the portion of the outer convolution of the hairspring immediately adjacent the radially-outer end of the stopreach I l. The dotted lines 26 in Figs. 1 and 5 are concentric with respect to the central axis of the collet l3 and the said line 26 serves to indicate the circumferential coincidence of the parts just referred to prior to being stressed, in the manner as will presently appear.

For the purpose of holding the free end of the outer convolution of the hairspring ill anchored in the anchoring-stud 23, a wedge-like retainingpin may be employed.

After the hairspring ill and its collet l3 have been assembled onto a balance-staff such as l6, such unit will be installed between the move ment-plates l8 and i9 so that the opposite ends of the balance-staff M respectively freely bear in the bearing-studs I 6 and l'l.- The unit-may now be turned in a counterclockwise direction (as viewed in the drawings), whereupon the sloping terminal-reach 12 will pass through the aperture 22 in the regulating-lever 2! with little, if any, direct manual deflection in a radial direction, which deflection may be provided by a pair of tweezers held by the assembler.

After passing the outer terminal end of the hairspring [0 through the aperture 22 in the regulating-lever 2 i, the continued turning movement of the balance-staff I 4 will cause the inclined terminal-reach l2 of the hairspring It! to 4 enter and pass through the aperture 25 in the anchoring-stud 23. The wedge-like retainingpin 2'! may now be inserted into the aperture 25 from a direction toward the said terminal-end, preparatory to clamping (Fig. 5) the portion of the outer reach of the said hairspring lying immediately adjacent the stop-reach I i, against the innerwall of the said aperture 25. -The driving in of the retaining-pin 2'! will seat the stop-reach ll against the adjacent face of the anchoringstud 23, as is indicated in Fig. 5, and a further "straighten out, as is indicated in Fig. 4, until the extreme end of the inclined terminal-reach I2 engages with the inner face of the said retaining-pin.

The engagement of the extreme end of the terminal-reach l2 with the inner face of the retaining-pin 21, as above described, serves to restrain the stop-reach l I from further straightening out under force exerted by the driving in of the-said retaining-pin, and thus very accurate location of the outer end of the hairspring such as Ill may be achieved uniformly from clock-to-clock.

It will be seen from the foregoing that by so shaping the end of the outer convolution of the hairspring in as to provide the stop-reach l i and the inclined terminal-reach E2 in such relationship that the extreme end of the said terminalreach substantially circumferentially coincides with the portion of the said outer convolution immediately adjacent the outer end of the stopreach H, the passage of the hairspring through apertures such as 22 and 25 is not materially interfered with. Furthermore, the stop-reach II is prevented from unduly straightening out when the retaining-pin 2'! or its equivalent is driven home, by the engagement of the extreme end of the terminal-reach l2 with the said retaining-pin or its equivalent,

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics ofthe invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

1. A spiral hairspring for timepieces having its outer convolution kinked to provide a relatively short integral inwardly-extending stopreach and a terminal-reach integral with the inner end of the said stop-reach; the said stopreach extending inwardly generally in a substantially-radial direction and the said terminalreach being inclined from the inner end of said stop-reach outwardly to a point substantially coinciding with an imaginary circumferential line touching the junction of the said stop-reach and the said outer convolution.

2. A hairspring-unit for timepieces comprising a collet; and a spiral hairspring having its inner convolution secured to the said collet and having its outer convolution kinked to provide a relatively short integral inwardly-extending stopreach and a terminal-reach integral with the inner end of the said stop-reach; the said stopreach extending inwardly generally in a substantially-radial direction and the said terminalreach being inclined from the inner end of said stop-reach outwardly to. a point substantially coinciding with an imaginary circumferential line touching the junction of the said stop-reach and the said outer convolution.

3. An anchorage for a hairspring in a time piece, comprising a kink in an end-convolution of said spring to form therein a laterally-extending stop-reach and a continuing terminal-reach extending in the general direction of said endconvolution; an anchor-member having an aperture through which said end-convolution extends with said stop-reach bearing against said anchor-member and said terminal-reach extending in toto beyond the latter; and a wedge forced in said aperture in the anchor-member to clamp said end-convolution in place therein, the taper 16 2 6 of the forced wedge extending in a direction to hold the clamped portion of said spring convolution in said aperture under sufiicient longitudinal tension to deflect said reaches toward said wedge and force the end of said terminal reach into permanent engagement with said wedge.

WALTER KOHLHAGEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Putnam July 23, 1940 Number