Improvements in Watch-case Springs.
Year: 1890

page_text: Date of Application, 24th June, 1890-Accepted, 26th July, 1890
COMPLETE SPECIFICATION.
Improvements in Watch-case Springs.
I, HERBERT JOHN ALLISON, of 52 Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention which has
been communicated to me from abroad by "Courvoisier Wilcox Manufac-
turing Co.," (Incorporated) of the City and State of New York, United States of
America, and in what manner the saine is to be performed to be particularly
described and ascertained in and by the following statement :-
This invention relates to improvements in lock and fly springs for watch cases and
it has for its object to facilitate the insertion of said springs into the watch case.
The invention consists in the novel details of improvement and the combination of
parts that will be more fully hereinafter set forth and then pointed out in the
claims.
Reference is to be had to the accompanying drawing forming part of this specifi-
cation, wherein,
Figure 1 is a partly broken face view of a watch case containing my improvements.
Figure 2 is a cross sectional view of the same, and
Figures 3, 4 and 5 are detail views of my improvements more fully hereinafter
explained.
In the accompanying drawing the letter A indicates a portion of a watch case
and B is its stem.
D is a lock or fly spring that fits within the case A and holds the watch cover
(not shown) closed or open. The spring D is curved to conform to the curve of the
case A and it has secured to it a back piece E. Screws a, that pass through the
case A and enter the back piece E, hold the latter and thereby the spring D, within
the case A
To place the spring D into position in the case A, it should be bent or
its ends moved toward each other (as in do:ted lines, figure 3 and full lines, figure 4)
to shorten the arc to permit its free entry. If the back piece E were one continuous
piece of metal secured to the spring D, sald spring could not be properly bent, and
therefore to place the spring D within the case would require much exertion, and
danger of scratching, injuring the case. To overcome this difficulty, I sever or
separate the back piece E, preferably about midway of its length, as at b, as clearly
shown in the drawing. The inner or severed parts of the back piece E, are free or
disconnected from the spring D (see figure 4) which leaves the spring D, free to
bend opposite the severed part b of the back piece E. The back piece E, at or near
its outer ends may be secured to the spring D, by rivets or solder. When the
spring D is bent to insert it in the case A, the severed ends b, of the back piece E,
move outwards slightly (as in figure 4) which gives freedom to the spring D in
bending.
When the spring D is to be placed in the case A, it is first bent as in figure 4 to
shorten the arc, or reduce the size of the spring, the inner severed ends of the back
piece E permitting the bending of the spring as before stated; the spring is then
passed into the case A. and as the arc of the spring is now less than the arc of the
case A, it is free to enter the same. The ends of the spring are now released when
it will expand to its proper size and thus fit snugly within the case A.
The screws a being next passed into the back pieco E, the spring will be firmly
held in the case.
Springs constructed according to my invention can be placed in the case with
much greater speed and case than where a continuous back piece is used, said latter
back piece being so stiff as to prevent the spring D bending to permit its easy and
nick insertion in the case

page_text: The stem B, in figure 2, is shown connected to the end of the lock spring D as
usual. The fly spring is also to be constructed as before stated.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is ;-
1. The spring D, combined with the separated back piece E, secured to the same,
substantially as described.
2. The spring D, combined with the back piece E, secured to the same at certain
points and separated transversely between its ends substantially as described and
for the purpose specified.
3. The spring D, combined with the back piece E that is secured to the spring D
near its outer ends and disconnected therefrom at its central part, substantially as
described.
4. The spring D, combined with the back pieco E that is secured thereto and
separated or severed as at 6 substantially as described.
Dated this 24th day of June 1890.
ALLISON BROS., .
Agents for the Applicant.