Improved Escapement for Rotating Pendulums of Timekeepers.
Year: 1895

page_text: Date of Application, 14th May, 1895-Accepted, 8th July, 1895
COMPLETE SPECIFICATION.
Improved Escapement for Rotating Pendulums of Timekeepers.
1, WILHELM KOHLER, of 61 Konigstrasse, Furth, Bavaria, Clock Maker,
do hereby declare the nature of this invention and in what manner the same is to
bo performed to be particularly described and ascertained in and by the following
statement:-
The object of this invention is an escapement for a rotating pendulum which
acts in such a manner that by the mere rotation of the pendulum in one direction,
a ratchet tooth attached to the turung spring draws away the stop under the
superincumbent tooth of the motive wheel, whereupon the succeeding tooth of the
motive wheel falls against a blade which is also attached to the turning spring
communicating an impulse to the rotating pendulum, the stop having meanwhile
returned arrests the motive wheel on its escape from the blade.
An escapement of this kind is shown in the annexed drawings.
Figure 1 is a plan.
Figure 2 a back view, and
Figure 3 a side view seen from right to left, showing the escapement in the
position where the motive wheel is lying on the stop
Figures and 5 views from above and behind in that position of the escapement
where the ratchet tooth has drawn away the stop under the superincumbent tooth
of the motive wheel, and the driving blade receives an impetus from the succeeding
tooth of the motive wheel.
a, Figures 2 and 3, is the flat turning aping which has attached to its lower
extremity the body of the pendulum a'. The upper extremity of the spring 18 held
fast between two flat plates & which are riveted together. The clamp b is fixed
into the notch of a cylinder b', and is held there by a horizontal pin ³ going
through the cylinder and the clamp b, so that the turning spring a independently
of the position of the works must always maintain an upright position. The
cylinder has near its upper extremity a flange and an arm b' projecting from
the latter. The flange is kept in contact with the plate e' by two screws o³, which
are screwed from below into the plate of the back of the works. The
cylinder projects a short distance above the flange, and this projection is located
in the plate c in a circular hollow.
The screws are only tightened far enough to allow of the cylinder 61 being
turned by its arm b' in either direction, as may be necessary for the accurate
suspension of the rotating pendulum.
Axially with the turning spring a short shaft a° 19 placed having its lower pivot
in the plate c' and its upper pivot in the plate c³ The lower pivot runs upon a
stone which is held by the cylinder bl in the plate c¹.
The ratchet tooth af is secured to the lower end of this shaft aº, so that its
height can be accurately regulated. This shaft carries besides on an arm a
stretching horizontally inwards, the diving blade a which is held firmly in this
arm by movable and interchangeable screws. The driving blade is passed through
a notch in the back plate r of the works, and comes out exactly over the motive
wheel 9. The arm a which holds the blade a' has a continuation a projecting
beyond the axis of the shaft aº, from the unattached end of which Figure 2, a
più a extends perpendicularly downwards. The lower extremity of this pin
catches into a fork which is fastened to the thining sping a.
When the pendulum a' tios in the direction denoted by the arrow in Figure 1,
the ratchet tooth a comes in contact with a cone or pawld which is attached to au

page_text: upward directed piece of a lever d³, so that it cannot slip out when the pendulum
turns in this direction. The tooth a' then displaces the cone or pawl d, and causes
the vibration outwards on its axis o of the lever d which carries the pawl. The
lever has on its inward directed extremity the stop and the safety stop dº.
By this oscillation of the lever the stop d'15-drawn away under the super-
incumbent tooth of the motive wheel g, so that this wheel is set in motion, the
ratchet tooth a'then immediately clips away from the pawl d just before the
driving blade a' has come into the path of the teeth of the motive wheel, and 18
now caught by the succeeding tooth of the motive wheel and turned with its
shaft a. By the coupling a', a³, this motion is communicated to the turning
spring a and thus gives an impulse to the pendulam. While this tukes place, the
tooth of the motive wheel on leaving the stop d' comes into contact with the safety
stop d which offers a sloping surface.
The tooth of the motive wheel glides along this sloping surface, thereby bringing
back the lever d³ to its original position. As the blado is turned in a
horizontal
direction, and the tooth of the perpendicular motive wheel lying on the blade
moves downward in the arc, there domes a time when the tooth slips from the blade
and the motive wheel becomes free. This wheel however 18 immediately arrested
by the stop d' which has meanwhile returned to its original position while the
pendulum is turning still a little further in this direction.
On the rotation of the pendulum now taking place in the opposite direction,
the ratchet tooth raises the pawl d and goes under it without displacing either
the lever or its stop from their position.
As soon as the ratchet tooth below the pawl d has moved away, the latter
through its own weight falls back into its original position.
After this change of direction in the rotation of the pendulum, the occurrences
formerly described again take place.
In order to ensure accuracy in the progress of the escapement, the following
method has been devised.
The lever is lengthened out sideways above its turamg point, that is, it is
furbished with an arm which is either made heavy enough, or is loaded with a
specified weight do, so that it overbalancos the lever d'.
When the works are exactly perpendicular, the effect of this loaded. arm dis
anch that the lever d' cannot exert any side pressure on the pins of its axis o, and
consequently these pins are not held fast in their position. The greatest advantage
afforded by this equalising arm is however, when the works are not accurately
mounted; for it that case the lover would, in the absence of this equalising aim,
have a tendency in consequence of its own weight to turn outwards on its axis o.
and to draw away the stop d under the superincumbent tooth of the motive
wheel g.
Of course after the escape of a tooth of the motive wheel, the lever dª would
through the action of the salety stop, return to its original position, but as soon as
the tooth of the motive wheel had again restored the safety stop to its original
position, the lever would immediately fall outwards, and the stop would loosen
the next tooth of the motive wheel. The motivo wheel therefore would often bo
loosened unnecessarily, and thereby the motion would be irrégular.
The equalising arm obviates this inconvenience as it counteracts every effort
of the lever to fall outwards of its own accord. In order still further to guard
against the lever & being impelled outwards by any concussion that the works may
auffer from blows or any other cause, it is furnished with a spring which acts
toward the outside of the lever d', and 18 aauged so as to hold it in its inward
position Figure 1.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed 1 declare that what I
claim 16 :-
1. An escapement for a rotating pendulum characterised as indicated in the

page_text: annexed drawings by having a specially placed shaft attached to the turning spring,
which carries a ratchet tooth and a driving blade so arranged with respect to a
pawl of the stop holder, and to the motive wheel, that the ratchet tooth always
exerts an equal hold upon the pawl, and that the middle operating lever arm of
the blade remains the same for the purpose of assuring to the timepiece a perfectly
regular motion.
2. A method of working the escapement for the rotating pendulum described
under Claim 1 characterised by having the stop holder which is made like a lever,
overbalanced, this is done most effectually by a loaded arm, so as to avoid on the
one hand a sideward friction of the axis of rotation of the lever in its soveral
positions, and on the other hand to prevent the spontaneous loosening of the stop
should the works not be hung perpendicularly
3. A method of working the escapement for the rotating pendulum described
under Claim 1 characterised by having the pawl of the stop holder acted on by
the ratchet tooth so arranged that this pawl through its own weight, falls back into
its original position, for the purpose of dispensing with the spring which would
otherwise be necessary, all as herein described and substantially as shown in the
annexed drawings.
1
1005
H. GARDNER,
Patent Agent, 166 Fleet Street, London,
Agent for the said Wilhelm Kohler.