IMPROVEMENTS IN WATCH ESCAPEMENTS
Year: 1885

page_text: COMPLETE SPECIFICATION.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. & Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN WATCH ESCAPEMENTS" (a communication to me from abroad by Gerson
Krichevski (Watch Maker) and Abraham Edmonds (Artist) both of the City
County and State of New York United States of America) and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
The object of this invention is to reduce the friction and increase the durability
of the escapement movement of watches and the invention consists principally of a
curved or circular detent or locking piece for the escapement wheel. The invention
also consists in giving said detent or locking piece a circular movement for releasing
the teeth of the escapement wheel. The invention consists also of the means
employed for rotating the escapement detent and of the construction arrangement
and combination of parts all as hereinafter described and claimed.
Reference is to be had to the accompanying drawings forming a part of this
specification in which similar letters of reference indicate corresponding parts in all
the figures.
Figure 1 shows the new escapement movement the parts thereof being in the
position they occupy when the escapement wheel is held by the locking piece or
escapement detent, the latter shown in section on line x of figure 5.
Figure 2 shows the same, the parts being in the position they occupy just as a
tooth of the escapement wheel is released by the detent or locking piece.
Figure 3 shows the same after the tooth has passed the detent, showing a tooth
of the escapement in engagement with the impulse pallet to the balance wheel,
I Drine G71

page_text: Figure 4 shows the same the parts being in the position they occupy at the time
the disengaging pallet passes the pawl or spring upon the escapement lever during
the return movement of the balance wheel. Figure 5 is an enlarged edge view of
the movement showing the hair spring and part of the balance wheel. Figure 6 is
a detail view Figure 7 is an enlarged perspective view of the detent having its
plate or arm slotted, and Figure 8 is an enlarged detailed plan view of a part of the
lever provided with a pin for reciprocating the detent.
A represents the lower plate, and B the balance wheel of the watch movement,
and C represents the escapement wheel. k is the staff on which the balance
wheel B is secured and on this staff k is secured the hair spring x shown in
figure 5. The staff k is provided with the disc roller which is formed with the
disengaging pallet m to act in connection with the escapement lever e, and spring n
as hereinafter described to vibrate the lever e. The staff k, is also provided with
the larger disc roller q, formed with the impulse pallet p, that intercepts the teeth
of the escapement wheel C and causes the wheel to impart new power to the
balance wheel.
a is the escapement detent or locking piece pivoted on its staff b and made
practically semi cylindrical or meniscus-shaped in cross section at the point where
the teeth of the escapement wheel come in contact with it. It is formed to present
the curved horn or surface a¹ at the point of contact with the teeth of the escape-
ment wheel. The detent a, receives rotary reciprocating motion upon its axis by the
vibration of the lever e acting through the disc or arm c secured to the detent and
the pin c¹ secured to the dise and entering the slot f made in the lever e; the
slot fand pin c¹ may be retained if desired that is to say I may form the slot fin
the plate or arm c, as shown in figure 7 and provide the lever e with pin c¹ as
shown in Figure 8, the pin being placed so that as the lever e vibrates past the
detent a, the pin c¹ will enter the slot fat each movement and rotary reciprocate
the detent a as above described.
The lever e pivoted at e², is held pressed constantly towards the escapement
wheel by the spring h, the free end of which presses against pin h¹ secured to the
lever, and the said lever e is provided with the above mentioned spring n that
: reaches past the free end of the lever so as to stand normally in the path of the
disengaging pallet m as shown clearly in the drawings.
The action of the escapement movement is as follows:-The escapement wheel
being held by the detent a and the balance wheel swinging in the direction of the
small arrows shown in the drawings the disengaging pallet m on the fixed disc
will strike the end of the delicate spring n and carry the lever e to the dotted line
marked e¹ in Figures. 1 and 3. In moving to this position the lever e, will turn the
holding piece or detent a, and bring the curved portion a¹ thereof from in front of
the tooth of the escapement wheel C and let the tooth pass. At the time the tooth
passes the detent a, the impulse pallet p fixed to the disc q is carried to the dotted
line marked r, in Figure 1 and the instant the tooth of the escapement wheel leaves
the curved detent a, the tooth of the escapement wheel nearest the line marked r
'will strike the pallet p and throw the balance wheel with its staff and discs q, l,
and pallets m, p partly around the circle or nearly a whole revolution. The instant
the pallet m leaves the end of the spring n, the lever e is forced back by the spring h,
to its original position (that shown in full lines in Figures 1 and 3) which movement
of the lever e will turn the locking pallet a in position to intercept the next tooth
of the escapement wheel C. The hair spring a will now return the balance wheel
shaft k discs l, q and pallets m p, the spring n yielding to permit the pallet m to
A pin s is fixed
pass beyond it and past the lever e ready for another vibration.
in the plate A of the watch movement to prevent the lever e and detent a from
being moved too far and a pin s¹ is fixed in the disc q to prevent vibration of the

page_text: Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed I declare that what
I claim is
•
1. The detent a connected with the lever e by an arm or disc c and pin c¹
entering a slot in the lever substantially as described.
2. The semicircular detent a formed or provided with an arm or plate c sub-
stantially as shown and described.
3. In an escapement, the lever and the detent with its arm constructed as
described and provided with means for the mutual engagement of lever and arm as
set forth.