IMPROVEMENTS IN CLOCKS
Year: 1886

page_text: 1, HENRY DAVEY, of Rupert Lodge, Headingley, Leeds, in the County of York,
Engineer do hereby declare the nature of my invention for IMPROVEMENTS IN
CLOCKS and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
'My invention consists in mechanism for giving impulses to the pendulum, and
for indicating the time on the dials of master and secondary clocks. The pendulum
is made to receive an impulso only occasionally, say, once per minuto, and the time
is indicated in both the master and secondary clocks, by a simple ratchet move-
inent. On reference to the drawing a is a pendulum, of the proper length for
beating seconds. On one side of the pendulum is mounted a ratchet wheel b
having 30 ratchets. A pawl c prevents the ratchet wheel from turning contrary
to the direction of the arrow. On the axle of the ratchet wheel b is a moveable
arm d carrying on its upper, ond a pawl, engaging into the ratchet wheel b. The
lower end of the lever d is during the swing of the pendulum made to come in
contact with the stop g. By this means, every double swing of the pendulum
causos the ratchet wheel to turn in the direction of the arrow to the extent of one
ratchet. On the face of the wheel b there is a pin c. When the pin comes into
the position shown on the drawing it engages with tho pin fixed in the lower end
of the lever h. The lever turning on the fulcrum i causes an electric contact
maker to completo the circuit of the electro magnet n at the time when the
pendulum is at the full extent of its swing towards the left. During the swing
of the pendulum to the right an armature m attached to the lever h is attracted
by the electro magnet n thereby giving an impulse to the pendulum a through the
lever h. At the end of the impulse, the upper end of the lever h¹ breaks contact
with the electro inagnet and the lever being heavier below the fulcrum than above,
falls into a vertical position. On the return of the pendulum to the left, the
lever will have caused the pin in the ratchet wheel b to have moved out of
the way of the pin e' in the lever h. The pendulum will then be free to swing
under the influence of gravity for sixty seconds, at the end of which time, the pin
in the ratchet wheel b will again engage with the pin on the lever h and another
impulse will be given to the pendulum in the manner before described. t is a
ratchet wheel having 60 ratchets, and a hollow spindle to the outer end of which
is fastened the hour hand.

page_text: 8 is another ratchet wheel having 60 ratchets fixed on a spindle over the hollow
spindle of the ratchet wheel t and carrying the minute hand. Every twelfth
ratchet of the wheels is made a little deeper than the others. On the lever o is a
pawl made to engage in the ratchet wheel, and so shaped that when it falls into
the deep ratchets it also engages in the ratchet of the wheel t. The lever o is
moved by the action of the lever h¹ before described. The secondary clock is
cyncronized in the following way On the spindle of each of the hands is placed
a heart shaped cam At twelve o'clock, the master clock actuates a contact maker
and sends an electric current through the electro-magnet which attracts the
armature y and lifts the pawls ¹ which were engaging in the ratchet wheels t 8
at the same time bringing the levers ww to bear on the said cams. The said
wheels being free to move under the influence of the levers w w³ are both brought
to the position of 12. The master clock, having broken the current to the electro-
magnetz the pawls fall into the ratchets, and the normal movements of the clock
are resumed.
Having described my invention, and the manner in which it is carried out, what
I claim is:
1. Actuating the pendulum by means of an escapement, which gives the
pendulum an impulse at long intervals, substantially as described and shown on
the drawing.
2. Indicating the time on master and secondary clocks by means of mechanism,
substantially as described and illustrated.