AN IMPROVED ESCAPEMENT FOR WATCH AND CLOCK MOVEMENTS, APPLICABLE GENERALLY TO MACHINES WORKED BY CLOCKWORK
Year: 1881

page_text: LETTERS PATENT to Alexander Browne, of the Firm of Browne and Company,
of 5, Southampton Buildings, in the County of Middlesex, Patent Agents,
for an Invention of "AN IMPROVED ESCAPEMENT FOR WATCH AND CLOCK
MOVEMENTS, APPLICABLE GENERALLY TO MACHINES WORKED BY CLOCKWORK."
A communication from abroad by Edward Wensch, of Vienna, in the Empire
of Austria Hungary.
PROVISIONAL SPECIFICATION left by the said Alexander Browne at the
Office of the Cominissioners of Patents on the 20th June 1881.
ALEXANDER BROWNE, of the Firm of Browne and Company, of 5, Southampton
Buildings, in the County of Middlesex, Patent Agents. AN IMPROVED ESCAPE-
MENT FOR WATCH AND CLOCK MOVEMENTS, APPLICABLE GENERALLY TO MACHINES
WORKED BY CLOCKWORK.". (A communication from abroad by Edward Wensch,
of Vienna, in the Empire of Austria Hungary.)
In watch and clock mechanism constructed according to this Invention, instead
of the escapement transmitting the motive power direct from the escapement wheel
to the balance or pendulum, as is the case with movements as at prosent constructed,
the said escapement only serves to bend a spring, which after being set free by
means of the balance or pendulum, gives the impulse for the movement of the
balance or pendulum.
The said spring which only moves a short distance is of equal and continuous
moving power, and therefore always gives the same uniforın impulse to the balance
or pendulum, consequently an accurate movement is obtained for watch and clock
nechanism.
I will describe the Invention supposing the works to be constructed with a
balauco wheel. The balance is pivotted between the plate and bracket, and is
kept in position in the usual manner by a spring under the balance wheel, and on
its axis is fixed a small cam, and on the outside near the centre of the said balance
wheel a small pin is scrowed. A rod is pivotted on the plate; one end of this rod
"

page_text: is forked so that tho aforesaid cam may work therein; the other end of the rod is
of a T form, the arms being furnished with pins which catch in teeth of the
escapement wheel, which latter is pivotted to the aforesaid plato and a bracket, and
is actuated by the works. To the side of this last named bracket is fixed a flat
spring, the upper end of which comes against the aforesaid pin fixed near the centre
of the balance wheel; the said spring is provided with a peg so as to take in the
teeth of the escapement wheel. When the balance moves so far in one direction
that the aforesaid pin comes in contact with the spring, the cam has reached its
maximum travel in the left direction, and imparted this movement to the aforesaid
forked rod, therefore one pin on the T end of this rod is situated in and the other
pin out of the teeth of the escapement wheel, so that one pin stops this wheel. The
spring pressing on the pin on the balance, and being in tension drives the said
balance, and the stop or peg on the spring comes in contact with the next tooth of
the escapement wheel. By vis inertiae the balance moves further round. Tho
aforesaid cam and also the forked rod have now completed their action in this
direction, in consequence of which the pins on the T arms of the rod are reversed,
that is to say, the one which was engaged with the escapement whool is now
disengaged and the opposite one is engaged. The tooth of the wheel which was
engaged becomes set free, and the escapement wheel now moves so far until the
next tooth, which previously was free, is caught by the opposite pin. During the
above mentioned movement the spring is put in tension by means of the projection
or peg on the said spring. Now the balance makes its return oscillation, the pin
on the same comes again in contact with the spring, and the pin on the Ṭ end of
the rod being disengaged from the escapement wheel, this wheel sets free the
projection of the spring, and the latter gives the balance a new impulse in the
opposite direction, the pin again catches the escapement wheel, and so on.
The above action takes place as long as the escapement wheel is driven by the
motor. It is clear that by means of the above described arrangement the escape-
ment wheel does not transmit directly the motive power of the clock work to the
balance, but that the movement of the balance depends solely on the power of the
aforesaid elastic spring which remains always equal.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Browne in the Groat Seal Patent Oflice on the
20th December 1881.
ALEXANDER BROWNE, of the Firm of Browne and Company, of 5, Southampton
Buildings, in the County of Middlesex, Patent Agents." "AN IMPROVED ESCAPE-
MENT OF WATCH AND CLOCK MOVEMENTS, APPLICABLE GENERALLY TO MACHINES
WORKED BY CLOCKWORK. (A communication from abroad by Edward Wensch,
of Vienna, in the Empire of Austria Hungary.)
The object of my Invention is to provide a new and improved escapement for
watch or clock mechanism, in which the power is not transmitted directly from tho
escapement wheel to the balance or pendulum, whereby the action of the watch or
clock mechanism will be more regular and uniform than heretofore.
The Invention consists in an anchor rod pivoted on the top plate of the works,
and having its lower end T shaped with a tooth engaging with the escapement
wheel at the ends of this T shaped part, and the upper end of this rod is provided
with a fork surrounding an eccentric on the shaft of the balanco wheel, above
which eccentric there is a plate with a pin at the edgo which a spring presses
against for imparting motion to the balance wheel.
And in order to explain my said Invention, I will now proceed to describe the
same with reference to the accompanying Sheet of Drawings, in which
Figures 1, 2, and 3, are plan views of my improved escapement, showing the
same in its various positions.
The balance wheel b is pivoted to the top plate P of the works and the bridge %,
and is provided with a hair spring 8 in the ordinary manner. A small eccentric e
is mounted on the shaft or arbour of the balance wheel, and is embraced by the
prongs of a fork at the end of a rod 7, pivoted to a clip or bridge" and the top
plate P, and is formed T shaped at its lower end, and provided with teeth a¹, a²
An eccentric pin or stud i projects from the top of the balance wheel b, and a
spring reaching up to the centre of the balance wheel is attached to the bridge or
clip of the escapement wheel r; this spring f is provided with a tooth or
shoulder a, so fixed that it can engage with the teeth of the escapement wheel 7.
For pendulum clocks the construction would have to be modified slightly. The
operation is as follows :-
When the balance wheel b moves sufficiently far in the direction of the arrow x
that the pin comes in contact with the spring of (as shewn in Figure 1), the
eccentric e has reached its maximum action in the direction toward the left, and
as the fork of the rod g embraces this eccentric, the upper or forked end of the
rod g has also moved to the left, and by this movement the tooth a¹ is engaged
with the teeth of the escapement wheels, whereas the tooth a is disengaged, and
the tooth a¹ thus stops the escapement wheel r. The spring presses against the
stud i, and being in tension drives the balance in the reverse direction of the
arrow, that is, in the direction of the arrow y, and the tooth or shoulder a of the
spring comes in contact with the next tooth of the wheel r, as shewn in Fig. 2.
By its own inertia the balance is carried further in the direction of the arrow y,
and the eccentric e and the fork of the rod y have now reached their maximum
action in the right hand direction. The tooth a² is now engaged with the escape-
ment wheel, the tooth a¹ is disengaged, and the tooth of the wheel which has
been previously stopped by the tooth a' is released and the wheel ? moves so far
in the direction of its arrow that the next tooth which was previously free is
stopped by the tooth a. During this action the spring f has been put in tension
by the action of the tooth a³ on the tooth a of the spring. The balance b makos

page_text: its return movement in the direction of the arrow x, the pin i strikes the spring f.
the shoulder or tooth a is released from the tooth a³ and the spring f gives the
balance wheel a fresh impulse, and the above described operation is repeated.
These movements take place as long as the escapement wheel is driven by the
motor; by these means the escapement wheel does not directly transmit the inotive
power of the mechanism to the balance, but the movement depends on the power
of the spring which always remains regular. It follows that the movement of
clock mechanism which is provided with this escapement must be most exact, and
the action can never vary because the motive power of the spring falways remain
the same.
Figures 4 to 8 represent a modification of my escapement which is based on the
same principle, but may be preferable to the above described as far as regards
facility of execution, cheapness of production, and precision of work. Hero as in
the former escapement a small eccentric e is mounted on the shaft or arbor of the
balance wheel b, and is embraced by the prongs of a fork at the upper end of the
anchor rod g pivoted at x to the plate P; but instead of the T shaped end of the
said anchor rod this latter has two prongs p and 2' which alternately engage with
the teeth of the balance wheel h, one of which p is provided with a peak shaped
stop n. The lever pivoted at its lower is constantly pushed against the
axle of balance wheel by a small spiral springs; this lever f¹ is provided at a with
a stop which acts upon the teeth of the escapement wheel r.
1
In Figure 4 the balance has reached its maximum action towards the left,
imparted it to fork g, and forced the stop p¹ of the anchor rod into the teeth of
the escapement wheel r. As the latter is being turned from the mechanism in the
direction of the arrow tooth 3 of the escapement wheel rests against the prong p¹,
tooth 1 which rests against the stop of the lever f¹ moves the latter to the right
and spring s is somewhat strained. The pin i stands diametrically opposito the
end of the lever f¹, and has now reached its maximum distance from it. The
balance b swings back in the direction of the arrow, Figure 4, and assumes the
position shewn in Figure 5; the balance has now completed its maximum action to
the right. The eccentric e has shifted the fork of the anchor rod towards the
right, and the prong p against the escapement wheel 2, but has distanced p¹; in
consequence of this tooth 3 has been set free, and the escapement wheel r moves in
the direction of the arrow, Figure 5, till tooth 2 is arrested by prong p; tooth 1
has now slid away under the stop a, whereby the lever f' has been set froe, the
latter however is stopped by the peak n which has been moving downwards,
bearing against stop a. The pin i swings softly past the lever f¹ without affecting
however in their relations to each other the position of the above described parts
of the check movement; at this instance the return oscillation of the balanco b
occurs (as shewn in Figure 6), in consequence of which the eccentric e is again
moving the fork of the anchor rod g towards the left, and there removing (without
setting tooth 2 free at first) the peak n from the stop a of lever fl which was
pushed forward by spring s now bears against the pin i, to which it is imparting
the necessary impulso in moving the balance b till the stop a is caught by
tooth 5.
1
The motion of the balance continuing in the direction of the arrow (Figure 6)
the tooth 2 is now set free, and the escapement wheel turns round till it is stopped
again, which is effected by tooth 4 bearing against prong p'; tooth 5 has mean-
while set the lever f¹ up again, and is now assuming the position of tooth 1 in
Figure 4; the position of all the other parts of the mechanism likewise remains
the same, as shewn in Figure 4, and thus the movement is repeated in regular
alternation as long as the works remain in motion. In lieu of the spring a a lever
with a regulating weight G, as shewn in Figure 7, can be used to act upon the
striking lever f¹
A further modification is the application of an elastic main spring (Fig. 8), in
lieu of the striking lever ƒ¹ with the spring s in Figures 5 and 6, the mainspringf
being pivoted upon a bracket w, and having a stop a similar to that of the striking

page_text: lever f. In working one or the other of the modifications shewn in Figures 7
and 8 all the other parts of the check movement remain the same, as described
above, and shewn in Figures 4, 5, and 6; the same refers to all the movements.
It is evident from the description of the construction just given that the escapement
wheel r can in no way transfer the power of the motor to the balance wheel, and
that the motion of the balance itself only depends on the power or strength of
spring & (or on that of spring for weight g eventually) which always remains the
same, no matter whether one or the other of these springs or the weight shall be
wound up by the application of a greater or less force of the motor in question, and
that as a consequence the balance can but perform oscillations of a fixed and equal
duration, whereas the escapement wheel r is being checked effectively and in uniform
intervals of time by the anchor rod g which is regulated by the motion of the
balance. The modification just described can be applied to watches and clocks of
any kind.
Having thus described the nature and object of my said Invention, and the
means whereby the same may be carried into practical effect, I would remark in
conclusion that what I claim and desire to secure by the hereinbefore in part
recited Letters Patent is, an escapement and the various parts connected there-
with, all constructed and operated substantially as described with reference to the
accompanying Sheet of Drawings.
In witness whereof, I, the said Alexander Browne, have hereunto set my
hand and seal, this Twentieth day of December, in the year of our Lord
One thousand eight hundred and eighty ono.