IMPROVEMENTS IN CHRONOMETERS, CLOCKS, AND WATCHES, AND OTHER HOROLOGICAL INSTRUMENTS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Arthur Charles Henderson at the
Office of the Commissioners of Patents on the 3rd February 1879. A commu-
nication from abroad by Marie Edouard François, of the Republic of France.
ARTHUR CHARLES HENDERSON, of 6, Southampton Buildings, Holborn, in the
County of Middlesex. "IMPROVEMENTS IN CHRONOMETERS, CLOCKS, AND WATCHES,
AND OTHER HOROLOGICAL INSTRUMENTS." A communication from abroad by Marie
Edouard François, of the Republic of France.
The improvements relate, 1st, to the prime mover whose force is rendered precise,
constant, and invariable; 2nd, to the escapement by an improvement in the detent;
and 3rd, to the balance which by the distribution of articulations, and compensating
and regulating weights is rendered compensatory.
The object in creating the new motor is to constitute with a spring the equivalent
of a weight so as to obtain from it a precise, constant, and invariable force.
The modus operandi is as follows:-On the prolonged shaft of the pinion of the
time wheel of an ordinary clock, for example, is placed a small barrel which gears
with the centre pinion inside the small plate. The spring of this barrel may be
tightened at will, which communicates to the escapement the perfectly exact force
required.
In producing this force at the right pitch it becomes constant, since the spring
of the small barrel can no longer tighten or loosen except in the most restricted
limits.
To render the force invariable when the great barrel spring has reached the
limit of its course it instantly stops the movement; for this purpose the large barrel
has its shaft or arbor extended beyond the large plate for presenting a worm or
thread on which a nut runs.
The lid of the large barrel bears a plug which traverses the large plate, so as to
fix a ferrule there, or even a wheel; on this ferrule a shaft is fixed which freely
traverses the nut, and causes it to turn at the same time as the barrel. So that
when this latter is wound up the nut separates from the plate, and when the
barrel is nearly unwound it presses on a long spring which instantly stops the
movement.
The motion of the nut, the length of the thread on the shaft of the great barrel,
is utilized for acting by a rack and pinion on an index showing the force of the
spring at any time.
The constant force has no connection with the striking part of the clock.

page_text: To the motor accessories may be adapted, such as the days of the week, months,
phases of the moon, and so forth.
The improvements introduced in the escapement are, 1st, the rest of the escape
wheel occurs at the end of the detent; 2nd, the small spring is placed below the
detent on a ferrule in the same way that a spiral is placed on the seat of a cylinder;
3rd, the small spring can also be placed on the plate; 4th, the escape wheel may be
-placed.at.a_tangent.;-5th,-the-back-spring-is-placed on-the-plate.-
The
improvements_in_the_balance-comprise,-1st,-a-steel-frame_with_bent_arms_
-fixed-on-the-axis-of-the-balance,-and-a-copper-frame-fixed-on-the-steel-one-close-to-
the axis; 2nd, bent levers (but which may be straight) which are articulated to the
-steel-frame; 3rd, compensating and regulating weights fixed to the levers. The
ends of these levers are actuated by the copper frame when contraction or expansion
occurs, since the steel and copper contract and expand irregularly.
The steel frame instead of having arms in are sections may be entire circles.
Terminal indices of the weighted compensating and regulating levers show the 1
effect of the expansion and contraction.
Finally the compensating balance applies to circular balances and to pendulums.
The improvements herein mentioned are applicable to horological instruments in
general, to chronometers, watches, time pieces, clocks, and all mechanical pieces
requiring precision of motion.
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