IMPROVEMENTS. IN CHRONOMETERS OR OTHER TIMEKEEPERS
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Ignaz Herrmann at the Office of
the Commissioners of Patents, with his Petition, on the 24th September
1866.
I, IGNAZ HERRMANN, of Clerkenwell, in the County of Middlesex, Watch
Maker, do hereby declare the nature of the said Invention for "IMPROVEMENTS.
IN CHRONOMETERS OR OTHER TIMEKEEPERS," to be as follows:-
My Invention relates to improvements in the "escapement" of chrono--
meters or other timekeepers, whereby the balance receives its impulse from
suitable mechanism, as herein-after described, arranged and constructed in:
such manner and strength as may be found most convenient for the purpose.
required. This spring detent or hammer is a mechanical contrivance or
combination of parts for receiving the power from the "escapement wheel,"
and transferring it to the "balance," consequently the impulse is not given by
the power of the mainspring, but by means of this improved arrangement of
spring detent or hammer. This power is regularly brought into action by
each succeeding tooth of the escape wheel suitably constructed for this
purpose, as herein-after described, reference being had to the accompanying
Drawing, which shows a diagram of an arrangement of mechanism suitable
for carrying out my improvements.

page_text: pallet b; c is another roller of similar form but smaller; this roller c may if
desired be of similar form to a small "table roller," and having a small pin
placed parallel with the balance staff; d is a steel spring having its power
of action at d, where it is made thinner than the other part, as shown
at e; it is fixed to the plate or such part of the movement as may be most
convenient; is a piece of steel or arm fixed with a screw and steady pin to
the spring d; i is another piece of steel fixed to the spring d by a steady pin
and screw; the face l is jewelled to reduce friction, and placed at such an
angle as is best suited to the height the spring is required to be raised;
9 is the excape wheel, so placed and arranged that there is no connection
between the balance and escape wheel. The direction of its movement is
shown by the arrow, its number of teeth being determined according to the
number of vibrations required of the balance. h are vertical teeth placed at
such angles, back and front, either as shewn or as may be found most con-
venient; m are long horizontal teeth, and n are other teeth or projections of
triangular shape descending from the teeth m at such distance from their
points as may be required for obtaining sufficient strength; k is an arbor with
two pivots working in brass or jewel holes. On to this arbor are fixed two
pallet arms or levers o and p; the ends of these are furnished with jewels q
and r.
The face of the pallet q forms the circumference of the radius from
the centre k, the face of the pallet r being at an angle of about 85°, with a
line from its point to the centre k, and upon a level or in the same plane with
the teeth m, the pallet 9 being upon a level with the teeth n; t is a bar of
steel fixed on the axis k below the arm or lever a, of such length that by the
revolution of the balance the pallet on the roller c does not come in contact
with it; is a short prolongation of the bar or lever t; wis a small thin
spring of steel or gold fixed to the arm or lever by a screw, but longer, so
that the roller c acts upon it; u is a spring fixed to the plate or other part of
the movement by a screw and steady pin; y is a bracket having a set screw
(by preference brass), the tail of which is on a level with the bar or lever t;
a¹ is another bracket having a screw, the thread of which may be either below
or above the spring d, the inner face of the screw head forming a stop to the
spring d.
The action of the escapement is as follows:-The roller a is now moving
in the direction indicated by the arrow, the spring w is lifted or raised by the
point or projecting pallet of the roller c, the spring w resting at the end
against the bar or levert pushes it before it. The diagram shows it in the
position when it is on the point of being disengaged. The spring w acting on
to the end or prolongation of the lever or bar t forces it back until the arm

page_text: rests against the end of the screw z. The spring w must be sufficiently
narrow to be perfectly free of the thread of this screw z. The pallet arm or
lever o, q, being fastened to the axis k, the same as bar or lever t, by the
return movement of the levert the pallet 9 retires from before the teeth n of
the escape wheel which it had previously been detaining, and the wheel
forced on by the action of the main power in the direction of the arrow, the
face of the tooth h begins to act against the face of the piece 7, and moving
on raises the spring until the tooth marked h¹ has arrived at A, the pallet or
lever p, r, being also in motion with bar or levert has been brought to a
position to receive the point of tooth m at the same time that the tooth h¹
arrives at , and here it is detained, and the detent spring or hammer t is
now in a position to give impulse to the balance at the desired moment. The
balance having completed its vibration now returns, but this time the point of
the roller c passes the spring w without disturbing the rest of the escapement,
and the balance moves again in the direction of the arrow and moves the arm t;
the pallet or arm p, r, retires from before the face of the horizontal tooth m,
and allows the escapement to pass. By this movement the tooth h¹ retires
from beneath the piece of spring d until the tooth n rests against the face of
pallet o, q. The force of the spring d is now at liberty, and the time it is
unlocked the face of the impulse roller a, b, is before the end of the impulse
piece, the force or strength of the spring d acts freely against the face of
roller a and give it the impulse until it arrives again at the position shewn by
the diagram. By this arrangement the balance receives equal power of
impulse by every second vibration, and any irregularity of the main power
does not reach the regulating piece or balance, care being taken that after
allowing for wear and corroding of oil and dirt, sufficient power is still
supplied to the escape wheel to actuate the detent d. In chronometers for
pocket use two detents or springs d will be required, and the balance will
then receive double impulse, and therefor the motion of the wearer will not
stop it. The escape wheel in this arrangement will then require an additional
number of teeth m..