Year: 1888

page_text: Date of Application, 13th Oct., 1888
Specification Accepted, 23rd Nov., 1888
I, PAUL PERRET, of Chaux de Fonds in Switzerland, Watch Manufacturer do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement (reference being had to the accompanying drawings and to the letters and
figures marked thereon) that is to say :-
The improved construction of the crown and stem for stem winding watches,
hereinafter described, presents the double advantage of strongly securing the stem
in the pendant while allowing an easy withdrawal of the same, when the movement is
to be taken out of the case.
My system of crown and stem, of which figs. 1 to 5 of the accompanying drawings
shew different forms, which will be used according to the different systems of watch
cases, is essentially composed of a stem A provided with a square hole, or with some
other coupling arrangement intended to be connected with the stem of the movement;
of a crown B, of variable shape; of a screw nut C, which secures the crown to the
stem; and of the screws c which prevent the unscrewing of the screw nut C.
In those arrangements of crowns which are intended to be used in hunting watches,
whereby the screw nut C has to play as a push piece acting upon the secret spring of
the watch case, either the system shewn in Fig. 2, in which the screws c work
together as push screws acting upon the cannon D may be used, or the system shewn
in Fig. 3 in which the screw nut C is provided at the same time with push screws b
and with screws c, the latter being intended to secure the screw nut C as well from
In the construction shewn in
its unscrewing, as from falling out of the crown.
fig. 4, the screw nut works directly upon the stem A.
For the purpose of causing the crown to bear always upon the pendant, I place a
spring a between the cannon D, and the stem A (Fig. 3), or a spring a' (Fig. 4), or
an elastic ring a" (fig. 5) between the screw nut C and the crown B.
With the constructions shewn in Figs. 1, 2 and 3, the stem A can only be withdrawn
allow the
inward of the case-ring, whilst the constructions shewn in Figures 4 and
stem to be withdrawn out of the pendant, and still secure a very solid fastening of
the stem to the pendant. A ring R (Fig. 4) is placed between the cannon A of

page_text: stem A, and the crown B, and is free to turn around the stem. Two screws v, v,
the heads of which are lodged into the pendant, are screwed into said ring R, and
thus the stem is strongly affixed to the pendant, but still free to turn upon it. In
the construction shewn in fig. 5 the heads of the screws v, v, are covered by tho
border of the crown.
To withdraw the stem it will be sufficient to unscrew the screws v, v, or the pendant
may be provided, as shewn in fig. 6, with a bayonet slot.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same may be performed I declare that what I
claim is
1. The combination of the stem A having a coupling cylinder A¹, of the crown B
of any shape or configuration, of the screw nut C, and of the screws c, substantially
as shewn and described and for the purpose specified.
2. The combination of the steni A, having a coupling cylinder A', with the
cylinder D intended to act upon the secret spring in hunting watch-cases, the push
screws b, with or without screws c, the screw nut C acting as a push piece, and the
springs a, a', or a", substantially as shewn and described and for the purpose
specified.
3. The combination of the stem A, with ring R into which are screwed the
screws, v, traversing the pendant substantially as shewn and described, and for the
purpose specified.
T
1
1000