Improvements in Escapements for Clocks.
Year: 1892

page_text: Date of Application, 8th Oct., 1892
Complete Specification Left, 8th July, 1893-Accepted, 12th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Escapements for Clocks.
I CHARLES BALDOCK of Ware in the County of Herts, Gentleman, do hereby
declare the nature of this invention to be as follows:-
The object of the present invention is to provide a reliable escapement for
inexpensive clocks.
In carrying out my invention, I employ a single-impulse gravity escapement,
consisting of an impulse arm hinged near the suspension spring of the pendulum,
and carrying at its lower end a pivotted lifting hook. The beard of the lifting
hook takes into pins set on the face of an escape wheel, which forms part of
the train of wheels, under the influence of the clock spring, weight, or other
source of power. The tendency of the escape wheel is to draw the lifting hook,
and with it the impulse arm, away from the pendulum, an excessive tendency in
that direction being prevented by a balanced lever engaging with one of the arms
of a fly, which fly is geared with a wheel fast on the arbor of the escape wheel.
The pendulum is perfectly free in its swing in one direction, say, to the right,
but on its return swing to the left, it touches the tail of the pivotted lifting
hook, and raises the beard clear of the escape wheel pins.
The escape wheel, though released by the hook, cannot yet rotate, as the fly is
still held by the balanced lever before mentioned, so that the impulse arm will
follow the pendulum, when it again moves to the right, giving by its weight the
required impulse. This following movement of the impulse arm is, however, soon
arrested by a projection catching against the tail of the balanced lever, thereby
releasing the fly. At the same moment, the lifting hook is released by the
pendulum leaving the impulse arm, and the beard of the hook drops onto the
next pin of the escape wheel. The fly being now free, the escape wheel begins
to turn, and draw back the impulse arm to its first position, which has the effect
of dropping the balance lever in time to catch the next arm of the fly, as it comes
round.
October 1892
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Escapements for Clocks.
I CHARLES BALDOCK of Ware in the County of Herts, Gentleman, 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 :-
The object of the present invention is to provide a reliable escapement for
inexpensive clocks.
To this end, I employ, in conjunction with the pendulum, and a single impulse
gravity arm for giving the requisite impulse thereto, a specially contrived lifting
device for the gravity arm, and an escapement fly in connection therewith.
The lifting device consists of a ratchet wheel with many teeth, say 60 in a half
seconds clock, and a pivotted hook on the gravity arm engaging with said teeth.
The pivotted hook is raised by the pendulum from one tooth of the lifting wheel,
and, as the gravity arm thereby released, falls, is deposited in the tooth next
following, so that when the lifting wheel is allowed to rotate one tooth by the

page_text: release of the ny escapement, the gravity arm is lifted, and retained in a position to
give the next impulse to the pendulum.
The control of the fly is effected by an escape lever operated by the movement
of the gravity arm.
My invention is illustrated in the accompanying drawing, whereof-
Fig. 1 is a side elevation, with the front clock plate removed, and
Fig. 2 is a sectional plan.
A is the pendulum, which is hung to one side of the clock case. The pendulum
is shewn in its position of rest, and the extent of its swing is indicated by dotted
lines.
In the following description, I propose to designate the swing to the right, the
forward swing, and that to the left, the backward swing. B is a gravity arm
pendent from a pivot situated near the suspension spring of the pendulum. At the
lower end of the gravity arm B, upon a lateral extension thereof, is the pivotted
lever C, the long limb c of which, passing between adjustable regulating set
screws carried by the arm B, engages, by means of a hooked end, with the
teeth of the lifting wheel D.
The lifting wheel D is driven by means of a train of ordinary clock gearing,
whereof E is the great wheel upon the spindle of the spring drum; E' the centre
wheel, the arbor of which carries the hands; and E E' intermediate wheels
arranged in the usual way.
In the
D' is a toothed wheel fast on the arbor of the lifting wheel D, and engaging
with a pinion on the arbor of the fly F, which is thereby driven in the direction of
the arrow. The radial blades of the fly F may be any suitable number.
drawings, six are shewn. G is a three-armed lever, pivotted on a fixed bracket H,
in or near the plane of rotation of the fly, and constituting therewith an escapement
device.
The arm g is slightly the heaviest of the three arms, so that the tendency thereof
is to be depressed normally to obstruct the path of the fly blades, as indicated in
the drawing, or of a locking arm keyed on the fly arbor.
The depression of the arm g is, however, limited by the arm g¹ bearing upwardly
against an adjustable set screw on the bracket H.
The third arm g² of the lever G, when the clock is at rest, occupies a middle
position between the fixed stop formed by the set screw h, carried by the
bracket H before mentioned, and the movable stop, consisting of a set screw
carried by an extension 6* of the gravity arm B.
The operation of the various parts constituting the clock movement is as
follows:-
The clock is started by causing the pendulum A to swing forward, that is to say,
to the right. The projection a on the pendulum rod then touches the tail of the
lever C, thereby disengaging the nose of the long arm c from the tooth of the
lifting wheel D, wherein it rests.
The gravity arm B, previously raised by the lifting wheel D, is then at liberty
to follow the pendulum in its return or backward swing, the tail of the lever C still
being in contact with the projection a, and giving to the pendulum the impulse of
the falling weight of the gravity arm.
The movement of the gravity arm in this direction, in contact with the pendulum,
places the hooked nose of the lever C within the tooth of the lifting wheel D next
behind the tooth just released, and also, by means of the set screw carried by the
extension, strikes the arm g' of the lever G, and raises the arm g clear of the
blade of the fly F. The fly F is now free to rotate, which it does under
the influence of the wheel D' on the arbor of the lifting wheel D. At the same
time, the wheel D also rotates lifting with it the gravity arm B by means of the
lever C. This forward movement of the gravity arm removes the set screw carried
by the extension 6* from contact with the arm g³ of the lever G, the arm g of
which is thus allowed to drop, and catch the next advancing blade of 'the fly F.
This movement is repeated at each forward swing of the pendulum.

page_text: Among the advantages of this arrangement, besides that of being able to employ,
in small clocks, a gravity escapement, it will be found that there is little friction in
unlocking the escapement, as the blades of fly or locking arms are on an arbor
revolving at a higher speed than the lifting wheel, thus reducing the pressure
between the arm of lever b and the fly blades or locking arms.
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 :-
1. The employment, in conjunction with a clock pendulum and a gravity arm for
giving an impulse thereto, of a lifting wheel with teeth engaging with a hook
pivotted to the gravity arm, such hook having a tail operated upon by the
pendulum, for the purpose of disengaging the gravity arm, substantially in the
manner shown and described.
2. The gravity escapement for clocks hereinbefore described and illustrated,
consisting of a lifting wheel with teeth, a gravity arm carrying a pivotted book
engaging with the said teeth, and having a tail to come into contact with the clock
pendulum, an escapement fly, and an escapement lever engaging with the fly, and
operated by the movement of the gravity arm, for the purpose of controlling the
movements of the lifting wheel, substantially as explained.
Dated this 8th day of July 1893.
NEWTON & SON,
Agents for the Applicant.