Improvements in and relating to Escapements for Watches or Clocks.
Year: 1895

page_text: Date of Application, 2nd Sept., 1895
Complete Specification Left, 13th May, 1896-Accepted, 15th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in and relating to Escapements for Watches or
Clocks.
I, ANDREAS HILLGREN, of 15 Rue Necker, Geneva, in the Republic of
Switzerland, do hereby declare the nature of this invention to be as follows:-
In all escapements for watches used or known at present it has been observed
that it is not possible to completely poise in all the vertical positions of the watch
the variations arising from the contractions of the spiral-spring which gradually
alter the position of the centre of gravity of the balance-wheel during more than
one revolution of the latter, so that the counterweights which may be attached to
the balance-wheel are not able to completely poise the same.
One object of my invention is to provide means for exactly poising an
escapement of any construction whatever, in any vertical position of the watch.
My invention has further for its object to prevent another imperfection of the
well-known escapements especially of those known as: "bascule-escapements" or
detent-escapements," the so called: racing or galloping of the same, that is to
say the imparting of two or more impulses to the balance-wheel whilst the same is
moving in one and the same direction.
61
In view of realising the first of these two objects I provide two supplementary
gear-wheels, one of which is affixed to the axis of the balance-wheel and gearing in
the other one which is especially intended to poise the balance-wheel and its
spiral-spring in any position or contraction of the same; to that effect the
diameters and number of teeth of the said two wheels are so arranged as to
have the said poise-wheel making always less than one revolution during each
full revolution of the balance-wheel.
The second object of my invention is realized by providing a suitable pin on the
said poise-wheel in combination with a suitable catch-spring of the "detent" or
"bascule so as to bave the latter put out of action as soon as the balance-wheel
has fulfilled one complete revolution.
A further object of my invention is to provide means for temporarily stopping
the escapement-wheel whilst the balance-wheel is removed for repair.
In order that my invention may be the better understood I now describe the
same more in detail.
The axis of the balance wheel is provided with the usual spiral-spring and the
said balance-wheel-axis carries the usual disc with pallet, the latter being intended
to receive the impulses imparted to it by the teeth of the escapement-wheel.
In reach of the said escapement-wheel is placed the axis of the detent-lever which
is provided with a pallet intended to engage the teeth of the escapement-wheel;
the said axis is also provided with the usual spiral spring intended to normally
engage the pallet with the teeth of the escapement-wheel. The said detent-lever is
further provided with a second pallet which remains normally out of reach of the
teeth of the escapement-wheel when the escapement is going, but which may be
temporarily engaged with the said teeth by hand or with the help of any instrument
whatever when the wheel is to be stopped for removing the balance-wheel.
The well-known catch-spring is also provided which is intended to be acted upon
by the balance-wheel each time the pallet is to be disengaged from the teeth: of the

page_text: escapement-wheel. This spring may be acted upon by the pin fixed on the poise-
wheel or the said spring may be acted upon by a tooth directly connected to the
balance-wheel-axis. A pinion or gear-wheel is fixed to the said balance-wheel-
axis and engages a gear-wheel of larger size so as to always have the said wheel
fulfilling more than one revolution for each revolution of the pinion or gear-wheel,
that is to say of the balance-wheel-axis.
Now it is evident that if the diameter of the poise-wheel is for instance twice the
diameter of the pinion or gear wheel it will be possible to poise the balance-wheel
and its spiral-spring in any position or form of contraction which said spiral-spring
may assume during two full revolutions of the balance-wheel. This poising will
for instance take place by providing the poise-wheel with out-cuts or with counter-
weights suitably applied to one of its faces until a complete poising is obtained.
The pin on the poise-wheel and the spring are combined so that the latter is
lifted out of reach of the tooth by means of the said pin as soon as the balance-
wheel, and with it the said tooth has fulfilled one complete revolution with the
object of preventing the said spring from being acted upon a second time even if
the balance-wheel fulfils two complete revolutions.
Dated this and doy of Santamber 1895
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in and relating to Escapements for Watches or
[Clocks.
I, ANDREAS HILLGREN, of 15 Rue Necker Geneva, in the Republic of
Switzerland, Watchmaker 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 :-
In all escapements for watches used or known at present it has been observed
that it is not possible to completely poise in all the vertical positions of the
watch the variations arising from the contractions of the spiral-spring which
gradually alter the position of the centre of gravity of the balance-wheel during
more than one revolution of the latter, so that the counterweights which may
be attached to the balance-wheel are not able to completely poise the same.
"
One object of my invention is to provide means for exactly poising an escape-
ment of any construction whatever, in any vertical position of the watch.
My invention has further for its object to prevent another imperfection of
"bascule-escapements
the well-known escapements especially of those known as:
or "detent escapements," the so called: racing or galloping of the same, that is
to say the imparting of two or more impulses to the balance-wheel whilst the
same is moving in one and the same direction.
With the view of realising the first of these two objects I provide two supple-
mentary gear-wheels, one of which is affixed to the axis of the balance-wheel and
gearing in the other one which is especially intended to poise the balance-wheel
and its spiral-spring in any position or contraction of the same; to that effect the
diameters and number of teeth of the said two wheels are so arranged as to have
the said poise-wheel making always less than one revolution during each full
revolution of the balance-wlieel.
The said contractions of the spiral spring cause the centre of gravity of the
latter to be displaced every moment and thus the gravity of the spires affect the
exactness of poising of the balance wheel. My said supplementary gear wheels
are therefore intended to compensate the said action of the gravity of the spires in
their different states of contraction.

page_text: The second object of my invention is realized by providing a suitable pin on the
said poise-wheel in combination with a suitable catch-spring or passing spring of
the "detent" or "bascule" so as to have the latter put out of action as soon as
the balance-wheel has fulfilled one complete revolution.
A further object of my invention is to provide means for temporarily stopping
the escapement-wheel whilst the balance wheel is removed for repairs.
In order that my invention may be the better understood I have illustrated the
same by way of example only in the accompanying drawing which shows two
different constructions of my improved escapement, it being understood that I do
not limit myself to these constructions.
Figures 1 and 2 show one form of the improved escapement.
Figures 3 and 4 show another form or modification of the same.
Figs. 5 and 6 are diagrammatic views showing the application to a watch.
Similar letters of reference indicate similar parts in the various figures.
Figure 1 shows an escapement of the well-known "detent kind " provided with
my poise-wheel E with a detent-pin e fixed to the said poise-wheel and with a
means for temporarily stopping the escapement-wheel when the balance-wheel is
to be removed for repairs. In this figure the escapement is shown in the position
it ocenpies at the moment when the pallet b meets the teeth of the escapement-
wheel A.
In Figure 2 the escapement is shown in the position it occupies at the moment
when the pin e is about to escape from the spring b+ after having displaced the
latter so as to disengage the pallet 6 from the tooth of the escapement-wheel A.
An escapement of the well-known "detent kind" is shown in Figure 3, with a
detent-tooth ct fixed to the balance-wheel-axis and with a poise-wheel E and with
means for temporarily stopping the escapement-wheel. In this figure the escape-
ment is shown in the position in which the tooth c+ meets the spring b+ from left
to right with the object of moving the pallet b out of reach of the teeth of the
wheel A.
Figure 4 shows the same escapement in the positiou in which the pin e engages
with the spring b+ from right to left with the view of moving the same out of
reach of the tooth e+.
C is the axis of the balance wheel, which is provided with the usual spiral-
spring not shown and the said balance-wheel-axis carries the usual disc c with
pallet c', the latter being intended to receive the impulses imparted to it by the
teeth of the escapement-wheel A.
In proximity to the said escapement-wheel A is arranged the axis 62 of the
detent-lever B which is provided with a pallet intended to engage the teeth of
the escapement-wheel A; the said axis is also provided with the usual spiral-
spring (not shown) intended to normally engage the pallet with the teeth of the
escapement-wheel. The said detent lever B is further provided with a second
pallet which remains normally out of reach of the teeth of the escapement-
wheel A when the escapement is going, but which may be temporarily engaged
with the said teeth by hand or with the help of any instrument whatever when the
wheel A is to be stopped for removing the balance-wheel.
b+ is the well-known catch-spring which is intended to be acted upon by the
balance-wheel each time the pallet is to be disengaged from the teeth of
the escapement-wheel A. In the construction shown in Figures 1 and 2 this
spring 6+ is acted upon by the pin e fixed on the poise-wheel E. In the
construction shown in Figures 3 and 4 the spring 6+ is acted upon by the tooth c+
directly connected to the balance-wheel-axis. D is a pinion or gear-wheel fixed
to the said balance-wheel-axis and engaging a gear-wheel E of larger size so as to
always have the said wheel E fulfilling less than one revolution for each revolution
of the pinion or gear-wheel D, that is to say of the balance-wheel-axis.
Now it is evident that if the diameter of the poise-wheel E is for instance twice
the diameter of wheel D it will be possible to poise the balance-wheel and its
spiral-spring in any position or form of contraction which said spiral-spring may

page_text: assume during twò full revolutions of the balance-wheel. This poising will for
instance take place by providing the poise-wheel E with out-cuts or with counter-
weights suitably applied to one of its faces until a complete poising is obtained.
In the construction shown in Figures 3 and 4 the pin e and the spring b+ are
combined so that the latter is lifted out of reach of the tooth c+ by means of the
said pin e as soon as the balance-wheel, and with it the said tooth ct, has fulfilled
one complete revolution with the object of preventing the said spring + from
being acted upon a second time even if the balance-wheel fulfils two complete
revolutions.
The balance-wheel of the watch is supposed to be exactly poised so as to have
no point of its circumference liable to play as a pendulum or as a metronome in
any position of the watch containing the same.
Now this may be obtained as to the balance-wheel proper but the same is
necessarily combined with a spiral spring having its outer end fixed to the cock-
bridge and the inner end fixed to the axis of the said balance-wheel. A rule has
been found for giving to the windings of the spiral spring such a form as to balance
the combined balance-wheel and spiral-spring but the said rule is only true if one
considers the spiral spring as a rigid disc the centre of gravity of which remains
always the same. Now this is not at all the case in spiral-springs and their centre
of gravity is displaced at every contraction of the spring and also by changing the
vertical position of the watch. The centre of gravity will therefore always be
eccentric and the overweight concentrated there will act either as a pendulum or
as a metronome upon the balance wheel, according as the vertical position of the
watch is pendant up, pendant down, pendant left or pendant right.
In watches in which the balance-wheel makes less than one revolution such
action cf the spiral spring might be poised by means of a weight fixed to the
circumference of the balance-wheel but in those watches in which a very exact
regulation is required the balance-wheel makes more than one revolution and
therefore a device must be provided in which a suitable counterweight may act
upon the balance-wheel in proportion as the centre of gravity of the spiral-spring
is displaced this reaction being the same when the balance-wheel has made say a
quarter of revolution and when it has made more than one revolution.
In Figure 5 the watch is shown diagrammatically in the position with the
pendant to the left. The centre of gravity g of the spiral spring G will act like a
pendulum X and tend to cause the balance-wheel to rotate in the direction
indicated by the arrow 1, that is to say accelerate its rotation and the watch will
run too fast. Now I provide a pinion D fixed to the axis C of the balance-wheel
and a wheel E gearing with said pinion D and provided with a weight et which will
work like a metronome Y, the weight et being fixed to the wheel E will tend to
cause the latter to rotate in the direction of the arrow 2 tending to cause the watch
to run slower; if the weight et is suitably calculated it will poise the overweight
of the spiral spring G acting at the point g, that is to say the metronome Y will
counterbalance the action of the pendulum X.
The same will be the case if the watch is held in the position with the pendant
to the right shown in Figure 6, and also in any and every vertical position of
the watch.
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 :-
1st. In an escapement of any kind for clocks or watches, the combination of a
pinion or gear-wheel connected to the balance-wheel-axis with a wheel of larger
diameter intended to exactly poise the balance-wheel and its spiral spring in any
position or contraction of the same substantially as and for the purpose specified.
2ly. In an escapement of any kind for clocks or watches, the combination of a
pinion or gear-wheel connected to the balance-wheel-axis with a wheel of larger
diameter provided with suitable openings or outcuts to exactly- poise the balance-

page_text: wheel and its spiral-spring in any position or contraction of the same substantially
as and for the purpose specified.
3rd. In an escapement of any kind for clocks or watches, the combination of a
pinion or gear-wheel connected to the balance-wheel-axis with a wheel of larger
diameter provided with suitable counter-weights applied to one or to both of its
faces with a view of exactly poising the balance-wheel and its spiral-spring in any
position or contraction of the same substantially as and for the purpose specifie.l.
4th. In an escapement of the well-known "detent kind" the combination of a
pinion or gear-wheel D connected to the balance-wheel-axis with a gear-wheel E.
of larger diameter bearing an excentrical pin e intended to act upon the usual
catch-spring + of the detent-lever B with a view of disengaging the pallet 6 of
the same from the teeth of the escapement-wheel A substantially as shown and
described.
5th. In an escapement of the well-known "detent kind" the combination of the
axis of the balance-wheel with a tooth ct and with a pinion or gear-wheel D
engaging a gear-wheel E of larger diameter, the said wheel E bearing a pin e aud
the catch-spring b+ of the detent-lever B being so disposed as to have the said
pin e moving the said catch-spring + out of the path of the tooth ct as soon as
the balance-wheel has fulfilled one full revolution, substantially as shown aud
described.
6th. In an escapement of the well-known "detent kind" the combination of the
detent-lever B having the usual pallet b, with a supplementary pallet b' intended.
to stop the escapement-wheel A when the balance-wheel is to be withdrawn.
Dated this 13th day of May 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.