US2997841A

US2997841A - Security devices for the balance springs of watches

Info

Publication number: US2997841A
Application number: US718261A
Authority: US
Inventors: Loge Lars
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-03-03
Filing date: 1958-02-28
Publication date: 1961-08-29
Anticipated expiration: 1978-08-29

Description

L. LOGE Aug. 29, 1961 SECURITY DEVICES FOR THE BALANCE SPRINGS OF WATCHES Filed Feb. 28, 1958 2,997,841 SECURITY DEVICES FOR THE BALANCE SPRINGS F WATCHES Lars Loge, Spregaten 15, Stavanger, Norway Filed Feb. 28, 1958, Ser. No. 718,261 Claims priority, application Norway Mar. 3, 1957 2 Claims. (Cl. 58107) This invention concerns a security device for the balance springs of watches, in particular wrist watches. It has been found, especially with small watches, such as wrist watches that the balance spring which is attached at its inner end to the balance wheel shaft and at its outer end to an adjustable anchorage, has a tendency to become dislocated should the watch be subjected to impacts, becoming wedged or causing irregular running. The end of the outermost winding of the spring, which is threaded generally through a slit in a post underneath the hairspring regulator also has the same tendency to become dislocated and to jam when subjected to impact-although not so frequently as is the case with the outermost part of the spring preceding the anchorage. The invention has for object to eliminate these troublesome jammings which are a great inconvenience to watchmakers,

According to the invention, one or more spring tongues capable of vibrating upon shock are associated with the balance spring mounting to assist the balance spring to return to normal position after dislocation.

A device according to the invention is shown by Way of example in the accompanying drawing, wherein:

FIGURE 1 shows in plan a balance spring assembly according to the invention.

FIGURE 2 is a side elevation looking in the direction of the arrows 22 FIGURE 1 and FIGURE 3 is a side elevation looking in the direction of the arrows 3-3 FIGURE 1.

Referring to the drawings the reference 1 indicates a watch casing and 2 the balance wheel support plate provided with an extension 3 fitted with a downward directed post 5, to which the outer end of the balance or hair spring 4- is fastened. The inner end of the spring 4 is fastened to a sleeve 6 on a balance wheel arbor 7. The outermost winding of the spring passes through a slit or groove 13 in the downwardly directed post 10 forming part of a regulator 9 for the hairspring. When the watch is subjected to a violent shock, the spring 4 tends to jam against the post and partly against the post 10. To

tea ii atent G avoid this effectively, there is provided a tongue 11 of spring metal attached to lower end of the post 5, the tongue curves upwardly creating a slanting passage for the spring 4 if dislocated to slide or glide back into its appropriate place.

The tongue 11, which has a free upper end and being made of springy material, will start vibrating when the watch is subjected to shock, thereby facilitating the guiding back of spring 4. To the same effect a similar tongue 12 has in the example illustrated, been attached to the lower end of the post 10. The spring tongues 11 and 12 need not necessarily be fastened to the

posts

5 and 10, but may be attached to independent posts or formed as an integral part of the

post

5, 10 or the hair-spring regulator extension 3 respectively.

What I claim and desire to secure by Letters Patent is:

1. In a watch balance spring assembly including a balance wheel support plate, an extension on said plate for supporting a post, a post fitted on said extension and extending downwardly from the balance wheel support plate, an arbor on said balance wheel, a sleeve on said balance wheel arbor, a balance spring fastened on its inner end to said sleeve, a regulator for said spring constituting a post having a slit through which the outermost winding of said spring passes, a tongue of spring metal extending outwardly from the axis of said post in an inclined path toward the plane of said support plate whereby said tongue prevents entanglement of the balance spring with said post by creating a slanting passageway for said spring when said spring is dislocated by a shock to jam against said post and thereby provides a return guide for said balance spring.

2. The device of claim 1 wherein the said tongue is attached to the lower end of said post and there is provided an additional tongue attached to said regulator to facilitate guiding of said spring away from a jammed position against said post when the watch is subjected to impact thereby facilitating relocation of the balance spring.

References Cited in the file of this patent UNITED STATES PATENTS 361,850 Van Strait Apr. 26, 1887 2,105,966 Bowen Jan. 18, 1938 FOREIGN PATENTS 219,447 Switzerland May 16, 1942