Improvements in Electric Clocks.
Year: 1894

page_text: Date of Application, 9th Jan., 1894
Complete Specification Left, 8th Oct., 1894-Accepted, 9th Jan., 1895
Improvements in Electric Clocks.
I, ERNEST HERBERT, of 25 New Kent Road, in the County of Surrey,
Watchmaker, do hereby declare the nature of this invention to be as follows:-
The object of my invention is to provide an improved electrical or electro-
magnetic clock or time-piece in which the required impulse is imparted by gravity
to the pendulum at each oscillation thereof.
My improved clock or time-piece comprises an electro-magnet which is included
in an electric circuit arranged to be alternately closed and interrupted by the
action of the pendulum, and the armature of which is suitably pivoted or otherwise
supported in such a manner that it will be alternately attracted by the magnet and
allowed to act by gravity upon the pendulum to give the necessary impulse
thereto at each oscillation to keep the said pendulum in motion. This armature
is provided with an adjustable weight for regulating or determining the force
of the impulse thus imparted to the pendulum. An adjustable stop is also
provided for limiting the movement of the armature under the action of gravity.
Near the top of the pendulum-rod I provide a small slide or sliding contact-
piece which is actuated by the pendulum and which is so arranged that, when the
pendulum in its oscillation has very nearly reached the armature, the electric
circuit in which the magnet is included will be completed and the armature con-
sequently attracted and drawn away from the pendulum to such a distance that
the pendulum, in its normal swing, will almost touch the said armature, and
immediately the pendulum begins to recede, the contact will be broken and the
armature will be swung about its pivot by gravity, thus imparting the required
impulse to the pendulum. I find it advantageous to employ for this purpose,
preferably near the top of the pendulum-rod, a sliding tube weighted adjustably
and mounted upon a stationary rod and provided with a platinum or other suitable
contact-piece on one side of the pendulum and with an insulated arm on the other
side of the pendulum, so arranged that the pendulum, in its oscillation, will impart
to-and-fro movement through a very short distance to the said sliding tube.
The said contact-piece and the insulating arm are preferably made adjustable on
the said tube so that the action of the magnet can be very efficiently regulated or
determined. This is an important feature of my invention, as the armature should
not be allowed to strike the pendulum with any appreciable force or to fall further
than through a very small distance upon the pendulum.
By my invention 1 am enabled to so adjust the parts that the pendulum-rod
will, at the termination of its oscillation on one side, all but touch the extremity
of the armature while the said armature is held by the magnet, and the electrical
contact will then be broken so as to permit the armature to move by gravity
through the required arc with the pendulum and thus impart the necessary
impulse thereto without striking or falling upon the same with any appreciable
degree of force.
The armature is provided with a pawl or pallet having an adjustable weight and
adapted to engage with a ratchet-wheel or star-wheel suitably geared with the
hands of the clock, so that, when the armature is attracted by the magnet, it will
impart movement through a predetermined augle to the second-hand or minute-
band of the clock. A weighted click or retaining pawl is also provided for

page_text: checking the movement and preventing backward movement of the said ratchet-
wheel.
To prevent acceleration of the pendulum, I provide a suitable check, preferably
consisting of a tube provided with projecting arms or pins and with a suitable
weight, and arranged to slide upon a stationary rod. The said arms or pins are
made adjustable on the sliding tube and are secured at such a distance apart on the
said tube that, in the normal oscillation of the pendulum, the said sliding tube will
be moved to and fro by the pendulum through a very short listance. The friction
between this tube and the rod upon which it slides prevents acceleration of the
pendulum. By varying the weight attached to the sliding tube, the amount of
friction between the said tube and rod can be increased or diminished as may be
required to properly check the movement of the pendulum and prevent its striking
or bouncing against the armature.
It is obvious that I can, if desired, employ two sets of armatures and magnets,
one on each side of the pendulum. I consider it more advantageous, however, to
employ only one armature and one magnet.
Dated the Ninth day of January 1894.
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.
I ERNEST HERBERT of 25 New Kent Road, S.E. in the County of London
and Surrey 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 :-
My invention refers to that form of electric master clock in which a pendulum is
kept in motion by the falling of its own weight of the armature of an electro
magnet from a constant hight, and the motive power of the clock is obtained from
the movement of the armature when attracted by the electro magnet.
I provide a pendulum P. supported by a pendulum spring S. an electro
magnet E. having an armature A. pivotted at a. To the armature A is attached
a dropping pawl L pivotted at e which moves the first wheel of the clock train.
To readily adjust the momentum which the armature conveys to the pendulum
at each impact I provide an arm B to the armature A on which is attached a
weight W by a screw or other suitable means, so that the weight W can be moved
backwards or forwards along the arm B, thereby increasing or diminishing the
force of the impact of the armature A on the pendulum P.
Upon a rod R fixed at r near the top of the pendulum is a sliding piece C (not
touching the pendulum made of some conducting material to which is attached two
prongs, claws, or other suitable pieces (K, K¹) one of these has its end R of some
insulating material and the other has its end K¹ of some conducting material
preferably platinum. On the pendulum rod or spring opposite this point is fixed a
plate of platinum (t) or of some other suitable material. Between the prongs K
& K' the pendulum rod or spring moves as it oscillates carrying the sliding piece C
with it, during part of its motion.
Three wires hi form part of an electric circuit. The wire g is connected with
the sliding piece C. The wire i joins the pendulum rod or spring to the magnet E
and the wire h is joined to the magnet so that when the uninsulated prong K is in
contact with the pendulum spring or rod at t the circuit is completed as in
Fig. II.

page_text: To prevent acceleration of the pendulum and the bouncing against the armature
consequent thereon I provide a sliding piece D fixed on a rod N preferably at the
lower end of the pendulum and of suitable weight with prongs claws or other
suitable pieces (n & n') between which the pendulum moves freely only so long as
its arc of vibration is not greater than the required amount.
But if the vibration increases so that the pendulum rod touches the claws (n, n¹)
it has to move the sliding piece D and so the viberation is checked by the inertia
of D & its friction on the rod N. To start the clock the pendulum is moved.
As the pendulum approaches the armature A it makes contact between the
plate t and the point K and the electric circuit is completed as in Fig. II & the
armature A is attracted to the magnet E.
The pendulum carries the slide with it and the circuit remains complete untill
the pendulum begins to recede as in Fig. I. The plate t then leaves the point K¹
this breaks the circuit and the armature falls by its own weight upon the pendulum
giving it its impulse.
The pendulum continues to move coming against the insulated point K as in
Fig. I thereby carrying the slide with it untill it begins to turn and again approaches
the armature.
Fig. I shows the armature A when released from the magnet E acting on the
pendulum.
Fig. II shows the armature A when attracted by the magnet E owing to the
electric contact between K¹ & t.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is
(1.) The mode of completing the circuit by a sliding piece moved by the
pendulum substantially as above described.
(2.) To prevent the acceleration of the pendulum and to prevent bouncing
against the armature by the pendulum, and to prevent uneven swinging, a check
acting by inertia and friction consisting of a sliding piece which allows the pendulum
to move freely only when the viberation does not exceed the required amount,
operating substantially as above described.
(3.) The mode of regulating the impetus of the armature by a moveable weight
attached to it.
(4.) The combination of each of the above with one another and with a
gravity armature worked by electricity and imparting momentum to a pendulum.
Dated this 8th day of October 1894.
ERNEST HERBERT.