Improvements in Escapements for Watches and Clocks.
Year: 1888

page_text: Date of Application, 22nd Sept., 1888
Complete Specification Left, 21st June, 1889-Accepted, 27th July, 1889
PROVISIONAL SPECIFICATION.
Improvements in Escapements for Watches and Clocks.
I, ALEXANDER KAISER of Fribourg, Switzerland Engineer do hereby declare the
nature of this invention to be as follows:-
These improvements relate to the production of escapements for watches and clocks
of simple construction and easy management which, as they allow of the employment
of heavy balances or pendulums, are little affected by variations caused by shaking
or shocks, and therefore the utmost regularity in the going of the watch or clock is
secured.
The construction shown in sheet 1 of the Drawings consists
1. of the escape wheel A turning on the axis ff and having specially shaped
teeth a a.
2 of the escape roller or cylinder B having a notch adapted to receive the teeth
a a of the escape wheel A, and passing so far into the said escape wheel that the
chord c d is nearly equal to the distance apart, or pitch, t¹ of the points of the teeth
of the escape wheel.
3. of the double fork C which is fixed to the escape roller B and turns with it on
the axis or arbor g g¹, and
4. of the pins D D which move with the balance or pendulum.
The
Assuming that in Figures 1 and 11 the escapement is at rest, after the running down
of the driving power; immediately the driving power is wound up again the tooth a
of the escape wheel A which is in the notch b of the roller B acts upon the latter in
the direction of the arrow shown in the escape wheel A and moves the said roller
with an accelerating force into the position shown in Figure 1ª whereby the double
fork C transmits this accelerating action directly to the impulse pins D D.
next tooth a of the escape wheel now rests against the roller B whilst the impulse
pins complete their oscillation to the left (that is to say in the direction of the hands
of the watch or clock). The oscillation in the opposite direction causes the pin D
when it reaches the position shown in dotted lines in Figure 11 to strike the double
fork again and to carry it, and therewith the escape roller B, into the position
shown in Figure 1°, from whence the pins D are free to complete their oscillation to
the right from the positions shown in dotted lines in Figure 11 to the positions shown
in full lines in Figure 1°.
In passing from the position shown in Figure 11 into the position shown in
Figure 1 the escape roller has to pass through the positions shown in Figures 1
and 1. At the moment when the escape roller reaches the position Figure 1b the
locking of the escape wheel A by the escape roller ceases; the escape roller is still
moving with nearly its greatest speed while the inertia of the escape wheel A has first
to be overcome before it can be put in motion from the state of rest; when the
oblique part of the tooth a of the escape wheel approaches the side of the roller only
the resistance of a very short backward push is presented to the attainment of the
position shown in dotted lines in Figure 11, which resistance is easily overcome in
consequence of the smallness of the angle ¹¹. A spring arrangement may be
applied to the escape wheel A, or to one of the next wheels in the driving train if
it is desired to soften the backward shock. When the impulse pins D D have
completed their oscillation to the right and begin to move back in the opposite
direction one of them again strikes, in the dotted position 11, the double fork and
continuing its movement, brings the escape roller B into the position shown in
Figure 1 where a fresh impulse is given to it by the tooth of the escape wheel A, and
from whence the above described cycle of operations is repeated anew.
It should be remarked that in the passage from the position 1° or 1° to the

page_text: position 1" the edge y of the notch in the escape roller B has a much longer distance
to traverse than the adjacent tooth a of the escape wheel A, in consequence of which
the latter always follows closely the edge y of the escape roller in order to act accel-
leratingly on the said roller.
In the construction shown in sheet 2 the backward push a¹ of the escape wheel
is altogether avoided by making the escape roller B of two concentric cylindrical
pieces B and B of unequal radii 71 and 11, but with a common tooth space or
notch b.
In the construction shown in sheet 2 Figures 2, 21, 2ª, 2ª¹, 2b, 2b1, 2º, 2º¹, and 2
show the parts in positions analagous to those shown in the construction illustrated in
sheet 1. It will be seen by the positions Figures 2°, 21, and 2 that when the
difference between the radii 111 is equal to, or greater than the distance a¹ by
which the escape wheel can spring forward, while the edge y passes from the position
Figure 2b into the position Figure 21 or Figure 2, no backward shock is occasioned,
but the adjacent tooth a thereby simply quits the surface of the roller B¹ and comes
to hear on the surface of the roller B.
For holding the escape roller securely in the position of rest during the free
movements of the impulse pins D D the arms of the double fork can be so
lengthened that they bear against the disc F on the balance arbor.
The balancing of the double fork can be effected by a correct distribution of the
mass of the roller as shown in the Figures in sheet 1, or by special counterweights G
as shown in the Figures in sheet 2.
The position of the impulse pins in Figures 1 and 2 may be taken as the middle
position, or better still the position in Figures 11 and 21, so that accelerating action
takes effect immediately the driving train is wound up.
If a second notch 6 is formed on the acting surface c d (Figure 1) of the escape
roller B the recoil of the roller can be reduced one half without the impulse action of
the escape wheel thereon being shortened. From this it follows that by a correct
distribution of notches on the whole circumference of the roller, and corresponding
arrangement of suitable fork arms C a rotating escapement Figures 3 and 3¹ plate 3,
can be produced which moves one division backwards and two divisions forwards.
A sufficient security for the holding of the escape roller B in the position of rest is
afforded by the special form of the fork arms C Figure 3, as an improper
movement of the said roller is always prevented by the disc F, whilst by the
oscillation to the right, of the impulse pin D the latter, immediately after a completed
revolution of the escape roller, is prevented from turning further in the direction i k
and the escape roller is held till the next tooth a of the escape wheel comes to rest
upon it. The holding of the escape roller may be effected in a manner similar to that
shown in the construction illustrated on sheet 2, or a special safety wheel may be used
for this purpose. D m is the middle position for the balance or the pendulum. It
may also be observed that in the oscillation of the pin D to the left the releasing of
the escape roller, in the construction shown in Figures 3 and 31, takes place with
proportionally less speed in consequence of the form of the arms C, so that the
tooth a of the escape wheel always follows the edge y of the escape roller closely and
consequently can always impart an impulse thereto.
As compared with the so called anchor escapement the above described arrange-
ments are distinguished by the following characteristics
1. The lever arm of the chief resistances to be overcome is, in the escape roller B,
half what it is in the corresponding anchor H Figure 0. (In the anchor escapements
there also occurs a slight recoil (Rückstoss) of the escape wheel in consequence of the
necessary entrance (anzug) when leaving the position of rest.
2-The transmission of power is effected in the constructions shown in Figures 1 to 3
by tooth engagement for nearly the entire duration of each impulse of the escape
wheel, partially in a manner similar to that mostly employed in chronometer
escapements (In anchor escapements it may happen that the tooth of the escape.
wheel only comes into action on a part of the bearing; surface of the anchor arm,
whereby the already very small impulse is still more shortened).

page_text: 3-The bearing surfaces of the constructions shown in Figures 1 to 3¹ (sheets 1, 2
and 3) move circularly and are formed of a cylindrical surface, whereby the
manufacture is materially facilitated (In anchor escapements the bearing surfaces
must be sloped down on account of the necessary entrance (anzug).
4-The release takes place in the above described constructions less suddenly than
in anchor escapements, and therefore the escapement wheel can follow closely tho
edge y of the notch in the escape roller and thereby act freely on the same.
5 In the construction shown in Figure 3 especially, the fork wheel can be
stamped out, and the corresponding escape roller can be drawn like a pinion, whereby
the manufacture and maintenance of this escapement is simplified as compared with
one having the usual toothed wheel with driver:
6 The advantageous use of the impulsion for the acceleration of the impulse
devices allows of the employment of heavy balances or pendulums which are less liable
to variations by shaking or shocks than light ones.
In comparison with the usual roller escapement Figure 0 0 the arrangements above
described possess especially the advantages of free motion, and of heavy balances or
pendulums; but the escape roller shown in Figure 2 also offers the advantage over the
usual escape roller of simplicity of construction and easy maintenance combined with
a powerful acceleration or impulse of the balance or pendulum.
In Figures 1 and 1ª of sheet + the escape rollers B1 and B2 are fitted direct on to
the axis of the balance wheel.
In Figures 2 and 2ª of sheet 4 the constructions shown in sheets 1 and 2 for
escapements with oscillating movements are reduced to the simplest form. By a
suitable choice of proportions the double fork C is replaced by the notch O and the
two impulse teeth and C" with the employment of one impulse pin D in connec-
tion with the balance or pendulum, while the shoulders H H, by pressing against
the teeth a limit the extent of the oscillations. The cam or tappet K with the safety
dise F prevents any prejudicial displacement of the escape roller. The friction on the
circumference of the escape roller B Figure 2, sheet 4, may be adjusted if required
by forming the surface at the radius 111 somewhat eccentric.
In the construction of the escapement shown in Figure 2 sheet 4 the escape roller B
can be made of one piece with the axis g g', because metal, steel wire for example,
can easily be drawn to the correct form with the teeth C¹ and C, the shoulders HH,
and the notches O and ; then broken off to the required lengths, and turned down
as may be required, only the cam or tappet K is in this case driven on to the axis g g¹
separately.
Dated this 21st day of September 1888
COMPLETE SPECIFICATION.
Improvements in Escapements for Watches and Clocks.
I, ALEXANDER KAISER, of Fribourg, Switzerland, Engineer, do hereby declare the
nature of the said 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 four sheets of Drawings annexed to my Provisional Specification:
--:
These improvements relate to the production of escapements for watches and
clocks of simple construction and easy management which, as they allow of the
employment of heavy balances or pendulums are little affected by variations caused by
shaking or shocks, and therefore the utmost regularity in the going of the watch or
clock is secured.
The construction shown in sheet 1 of the aforesaid Drawings consists:
1 of the escape wheel A turning on the axis f f¹ and having specially shaped
teeth a

page_text: 2 of the escape roller or cylinder B having a notch 6 adapted to receive the
teeth a a of the escape whee! A and passing so far into the said escape wheel that the
chord e d is nearly equal to the distance apart, or pitch, t t' of the points of the teeth
of the escape wheel.
3 of the double fork C which is fixed to the escape roller B and turns with it on
the axis or arbor g g¹, and
4-of the pins D I) which move with the balance or pendulum.
Assuming that in Figures 1 and 1' the escapement is at rest after the running down
of the driving power, immediately the driving power is wound up again the tooth a
of the escape wheel A which is in the notch 6 of the roller B acts upon the latter in
the direction of the arrow shown in the escape wheel A and moves the said roller with
an accelerating force into the position shown in Figure 1" whereby the double fork C
transmits this accelerating action directly to the impulse pins D D. The next tooth a
of the escape wheel now rests against the roller B whilst the impulse pins complete
their oscillation to the left (that is to say in the direction of the hands of the watch or
clock) The oscillation in the opposite direction causes the pins D when they reach the
position shown in dotted lines in Figure 11 to strike the double fork Cagain and to
carry it, and therewith the escape roller B into the position shown in Figure 1 from
whence the pins D are free to complete their oscillation to the right from the positions
shown in dotted lines in Figure 1 to the position shown in full lines in Figure 1.
In passing from the position shown in Figure 1 into the position shown in Figure 1°
the escape roller has to pass through the positions shown in Figures 1b and 11. At
the moment when the escape roller reaches the position Figure 1b the locking of the
escape wheel A by the escape roller ceases, the escape roller is still moving with nearly
its greatest speed while the inertia of the escape wheel A has first to be overcome before
it can be put in motion from the state of rest; when the oblique part of the tooth a
of the escape wheel comes against the side of the roller only the resistance of a very
short recoil has to be overcome to enable the escape roller to reach the position
shown in dotted lines in Figure 11, which resistance is easily overcome in consequence
of the smallness of the angle al, 2¹, 2. A spring arrangement may be applied to the
escape wheel A or to one of the next wheels in the driving train if it is desired to
soften the recoil. When the impulse pins D D have completed their oscillation to the
right and begin to move back in the opposite directions one of them again strikes, in
the dotted position 1 the double fork and, continuing its movement, brings the
escape roller B into the position shown in Figure 1ª where a fresh impulse is given to
it by the tooth of the escape wheel A, and from whence the above described cycle of
operations is repeated and so on continuously.
It should be remarked that in the passage from the position 1° or 1" to the
position 1d the edge y of the notch in the escape roller B has a much longer distance
to traverse than the adjacent tooth a of the escape wheel A, in consequence of which
the latter always follows closely the edge y of the escape roller in order tolact accelera-
tingly on the said roller.
In the construction shown in sheet 2 of the aforesaid Drawings the recoil a¹ of the
escape wheel is altogether avoided by making the escape roller B of two concentric
cylindrical pieces B and B of unequal radii and, but with a tooth space or
notch common to both.
In the construction shown in sheet 2, Figures 2, 21, 2ª, 2a, 2b, 2b1, 2, 21, and 2
show the parts in positions analogous to those shown in the construction illustrated in
sheet 1. It will be seen by the positions Figures 2b, 21 and 2 that when the difference
between the radii is equal to, or greater than the distance by which the
escape wheel can spring forward, while the edge y passes from the position Figure 2b
into the position Figure 21 or Figure 2 no recoil is occasioned, but the adjacent
tooth a thereby simply quits the surface of the roller B' and comes to bear on the
surface of the roller B.
For holding the escape roller securely in the position of rest during the free move-
ments of the impulse pins D D the arms of the double fork can be so lengthened
that they bear against the disc F on the balance arbor.

page_text: The balancing of the double fork can be effected by a proper distribution of the
mass of the roller as shown in the Figures in sheet 1, or by special counterweights G
as shown in the Figures in sheet 2.
The position of the impulse pins in Figures 1 and 2 may be taken as the middle
position, or better still the position in Figures 101 and 201, so that the accelerating
action takes effect immediately the driving train is wound up.
If a second notch is formed on the acting surface c d (Figure 1") of the escape
roller B the recoil of the roller can be reduced one half without the impulse action
of the escape wheel thereon being reduced. From this it follows that by a correct
distribution of notches b on the whole circumference of the roller and corresponding
arrangement of suitable fork arms C a rotating escapement, Figures 3 and 31, Sheet 3
of the aforesaid Drawings, can be produced which moves one division backwards and
two divisions forwards.
A sufficient security for the holding of the escape roller in the position of rest is
afforded by the special form of the fork arms C Figure 3 as an improper movement
of the said roller is always prevented by the disc F whilst by the oscillation to the
right, of the impulse pin D the latter, immediately after a completed revolution of the
escape roller prevents the latter from turning further in the direction ik and holds it
till the next tooth a of the escape wheel comes to rest upon it. The holding of the
escape roller may however be effected in a manner similar to that shown in the
construction illustrated on sheet 2, or a special safety wheel may be used for this
purpose. Dm is the middle position for the balance or the pendulum. It may also
he observed that in the oscillation of the pin D to the left the releasing of the escape
roller, in the construction shown in Figures 3 and 3¹ takes place with proportionally
less speed in consequence of the form of the arms C, so that the tooth a of the escape
wheel always follows the edge y of the escape roller closely and consequently can
always impart an impulse thereto.
As compared with the so called anchor escapement the above described arrange-
ments are distinguished by the following characteristics :-
1-The leverage of the chief resistances to be overcome (the recoil and slipping at
the release) is, in the escape roller B half what it is in the corresponding anchor H
Figure O sheet 3 of the aforesaid drawings (In anchor escapements there also occurs
a slight recoil of the escape wheel).
2 The transmission of power is effected in the constructions shown in Figures 1
to 3 by tooth engagement for nearly the entire duration of each impulse of the
escape wheel partially in a manner similar to that usually employed in chronometer
escapements (In anchor escapements it may happen that the tooth of the escape
wheel only comes into action on a part of the bearing surface of the anchor ariu
whereby the already very small impulse is still more reduced).
3-The bearing surfaces of the constructions shown in Figures 1 to 31 (sheets 1, 2
and 3) move circularly and are formed of a cylindrical surface, whereby the manu-
facture is materially facilitated (In anchor escapements the bearing surfaces must
be sloped down on account of the necessary clearance (anzug)).
4-The release takes place in the above described constructions less suddenly than
in anchor escapements and therefore the escape wheel can follow closely the edge y of
the notch in the escape roller and thereby act freely on the same.
5 In the construction shown in Figure 3 especially the fork wheel C can be
stamped out, and the corresponding escape roller can be drawn like a pinion whereby
the manufacture and maintenance of this escapement is simplified as compared with
one having the usual toothed wheel with driver.
6-The advantaneous use of the driving power for the acceleration of the impulse
devices allows of the employment of heavy balances or pendulums which are less liable
to variations by shaking or shocks than light ones.
In comparison with the usual roller escapement Figure 0 0 sheet 3 of the aforesaid
drawings the arrangements above described possess especially the advantages of free
motion, and of beavy balances or pendulums but the escape roller shown in Figure 2
also offers the advantage over the usual escape roller of simplicity of construction and

page_text: easy maintenance combined with a powerful acceleration or impulse of the balance or
pendulum.
In Figures and 1° of sheet 4 of the aforesaid drawings the escape rollers B¹
and B are fitted direct on to the axis of the balance wheel.
In Figures 2 and 2ª of sheet 4 the constructions shown in sheets 1 and 2 for escape-
ments with oscillating movements are reduced to the simplest form. By a suitable
choice of proportions the double fork C is replaced by the notch or by the two
impulse teeth C and C with one impulse pin D in connection with the balance or
pendulum while the shoulders H H, by pressing against the teeth a limit the extent
of the oscillations. The cam or tappet K with the safety disc F prevents any
prejudicial displacement of the escape roller. The friction on the circumference of
the escape roller B¹ Figure 2b, sheet 4, may be equalized if required by forming the
surface from the position of rest downwards somewhat eccentric that is to the
radins
In the construction of the escapement shown in Figure 2 sheet 4 the escape roller B
can be made of one piece with the axis g g' because metal (steel wire for example)
can easily be drawn to the correct form with the teeth C and C, the shoulders HH,
and the notches O and b; then broken off to the required lengths, and turned
down as may be required. Only the cam or tappet K is in this case driven on to
the axis g g separately.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
First In escapements for watches and clocks, the escape roller B furnished with a
notch and forked arms or impulse teeth C, and acting in combination with an escape
wheel A and impulse devices D substantially as herein before described, and illustrated
in the drawings herein referred to, and for the purposes specified.
Second Constructing the escape roller forming the subject of the first claiming
clause hereof with two cylindrical surfaces of unequal radii, as herein before described,
and illustrated in sheet 2 of the drawings herein referred to, and for the purpose
specified.
Third Constructing the escape roller forming the subject of the first claiming
clause hereof as a rotary escape roller as herein before described, and illustrated in
Figures 3 and 3' of the drawings herein referred to.
Dated this 21st day of Tuna 1000