Improvements in Means for Electrically Re-winding Clock or similar Mechanism.
Year: 1899

page_text: Date of Application, 25th Sept., 1899
Complete Specification Left, 25th June, 1900-Accepted, 11th Aug., 1900
PROVISIONAL SPECIFICATION.
Improvements in Means for Electrically Re-winding Clock or
similar Mechanism.
We, THE BRITISH THOMSON-HOUSTON COMPANY, LIMITED, and FRANK HOLDEN,
all of 83, Cannon Street, in the City of London, Electrical Engineers, do hereby
declare the nature of this invention to be as follows:-
This invention relates to a mechanism for rewinding clocks or other similar
apparatus by electrical means. Devices of this kind heretofore used or described,
have, in general, either failed in practice from one cause or another or have
possessed undesirable complications, and we believe the present invention to be
both novel and an improvement on these.
The novelty of this invention consists essentially in the contact opening and
closing device which is applicable to many of the well known electro-magnetic
arrangements used for obtaining a reciprocating motion by the use of electric
currents, which are periodically interrupted. This reciprocating motion may,
by the use of a pawl and ratchet or other common expedient, be made to wind
the clock.
The contact device may also be applied so that the reciprocating part itself
corresponds to the balance wheel of the clock, and the clock work being actuated
by a pawl and ratchet arrangement or otherwise. The contact arrangement is
such that when the movable member "A" of the electro-magnetic device has
reached a certain position in unwinding, it, by its movement, closes the circuit
of the electro-magnet.
66
The movable member A" carries a contact "B" extending at least over the
angle through which it is desirable to have the magnetic pull take place. When
the first contact is made the parts become magnetized and at once attract a
second contact piece "C" on to the movable contact "B" in opposition to the
spring attached to "C" which otherwise would keep the circuit open. The
movable member A" as soon as it moves, breaks the first contact, but the
circuit is held closed till the movable contact "B" breaks the circuit by sliding
by the attracted contact "C."
"
By this means the circuit of the electro-magnet is kept closed by continuous
contact between "B" and "C" for a greater or lesser fraction of the whole motion
of the movable member "A." During this period the magnetic pull is con-
tinuously exerted on "A" causing it to increase its velocity to any desired extent
before the circuit of the electro-magnet is opened by the contact "B" sliding
away from "C."
Part of the energy required for rewinding the clock or other device is stored
kinetically in the movable member "A" while under the influence of the

page_text: magnetic pull. The arrangement described affords a very simple means for
obtaining a cyclical movement of parts and enables all contacts to be of a rubbing
character, and we have found further that it enables us to entirely avoid all
injurious sparking of the contact pieces. In some cases we find it advantageous
to connect a small condenser between the contacts "B" and "C" or shunting the
magnetizing coil.
Dated this with don of C
3000
Improvements in Means for Electrically Re-winding Clock or
similar Mechanism.
We, THE BRITISH THOMSON-HOUSTON COMPANY, LIMITED, and FRANK HOLDEN,
all of 83, Cannon Street, in the City of London, Electrical Engineers, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to a mechanism for rewinding clocks or other similar
apparatus by electrical means. Devices of this kind heretofore used or described,
have, in general, either failed in practice from one cause or another or have
possessed undesirable complications, and we believe the present invention to be
both novel and an improvement on these.
The novelty consists essentially in the contact closing and opening device which
is applicable to many of the well known electro-magnetic arrangements whereby
a reciprocating motion is obtained by the use of electric currents. This recipro-
cating motion may be used for winding the clock in any one of the ways now well
understood.
Referring to the drawings in which the same letters indicate the same part,
Fig. 1 is a plan view of the clock and winding mechanism for use on either
alternating or direct current circuits, Fig. 2 is a side elevation of the same:
Fig. 3 is a sectional view on plane Z, Z (Fig. 2): Fig. 4 a detail of the winding
mechanism Fig. 5 a detail of the contacts: Fig. 6 a plan view of a modified form
of the contact mechanism of Figs. 1 and 2: Fig. 7 a plan of a simpler winding
mechanism for use on continuous current circuits and Fig. 8 a side elevation of
the mechanism shewn in Fig. 7.
The apparatus is composed of a clock mechanism and a winding mechanism.
The former comprising a main spring, intermediate gears, pinions and escape-
ment device, one of the several types of clock mechanism being clearly shewn in
Figs. 3 and 4: the winding mechanism, shewn in plan in Fig. 1, comprises an
electro-magnetic motor device for rewinding the main spring of the clock
mechanism together with suitable contacts for making and breaking the electric
circuits of the motor device at intervals as determined by the design of the
motor device.

page_text: The electro-magnetic motor, as shewn in the accompanying figures, has been
found to work well but we do not intend to limit ourselves to this precise arrange-
ment as there are evidently many. equivalents. which would be quite as satisfactory
to which the contact device may be equally- well applied..
Referring to Figs. 2, 3 and 4, one end of the main spring E is fastened to
the stud J fixed in the base F of the frame supporting the entire clock and winding
mechanisms. The other end of the main spring E is attached to the rotatable
shaft S. The ratchet wheel V, fastened to the shaft S, drives the gear G by
means of the pawl attached to the gear G by the pivot y. A small spring
fastened by stud z¹ to gear G maintains the pawla in contact with the teeth of
gear V. The gear G, mounted loosely on shaft S, drives the pinion L mounted
on the shaft b
2
The main shaft S passes through the plate F¹ and carries the armature A of the
electro-magnetic motor device. The relative movements of the several parts of the
clock and winding mechanisms during the unwinding period are indicated by
arrows. Referring to Figs. 1 and 2, the motor rewinding device is shewn as an
electro-magnet, P representing the iron core of the magnet and M the magnetis-
ing winding with terminals at screws e and b. The armature A is of iron and
provided with two curved wings W and W₁ also preferably of iron. A block T
of insulating material serves to support the steel or iron spring I and the metallic
contact support I, the former being attached by screws a and b, and the latter
by screws and d. The block T of insulating material serves as a terminal
support the screw e is connected to wire X of the current supply and the return
is made through screw H to wire Y. The iron core P of the electro-magnet is
attached to the non-magnetic plate F by means of screws Q, Q. The wing W
of the armature A carries a contact piece 1) and contact piece C' is mounted on
the end of a flexible contact support I¹. The spring I carries a smaller spring B
on which is mounted a contact piece C. N, N, are pieces of insulating material
serving to prevent spring I from touching the iron core P.
The spring E in unwinding causes the armature A to rotate as shewn by the
arrows. When contact D touches C, the circuit of the magnet winding M is
closed on the current supply mains X, Y: and current flows as follows:-from
wire to screw e, magnet winding M to screw b, thence by the resistance R to
screw, spring I contacts C¹ and D to wing W₁, armature A. shaft S, plate F
and by screw H to main Y. The resistance R is used to limit the current flowing
through the winding M on establishing contact at C, D. Upon the closure of
the circuit of the magnet winding M at the contacts C¹, D, the core becomes
magnetized, attracts the spring I and brings together the contacts C, W thereby
short circuiting the resistance R. The magnetic forces due to the first contact
are preferably not great enough to rotate the armature A, but with the increased
current consequent on making the second contact C, W the armature A rotates.
The wing Wis made of such a length that C does not leave it till the armature
has almost reached the position of maximum pull, as shewn by dotted lines, but
the armature continues to rotate through a considerably greater angle until
its kinetic energy is given up in winding the spring E of the clock.
The contacts C₁1) are separated by the first movement of A but as the
contacts CW are touching there is no spark at C, D), and when C and Ware
separate the velocity of C is so great that serious sparking is prevented.
While the device works well without a condenser it is advantageous to connect
a condenser K in multiple with the winding M thereby reducing possible sparking
between Cand W to a negligible quantity: a resistance R' of suitable value being
connected in series with the condenser with the object of preventing excessive
charging currents.
By this arrangement a cyclical movement of the parts is obtained and all
contacts are made of a rubbing character and therefore self cleaning; good
electrical contacts are thus obtained; an indispensable condition to successful
operation of such devices.

page_text: The contact C, is, as already stated, carried by a light spring B, itself attached
to the spring I. This precaution is necessary in the case of alternating currents
to avoid vibration and sparking at the contacts. The same arrangement will of
course operate equally well on continuous current, but a simpler form to be
described hereafter, is cheaper and quite as satisfactory.
In place of the spring I in Figs. 1 and 5, the arrangement of Fig. 6 may be.
employed without further modifications of the remainder of the apparatus shewn
in both Figs. 1 and 5.
P is the core of the electro-magnet with its winding M as in the other figures;
on the insulated block T is fastened a support U and acts as a pivot for the iron
armature A carrying the spring B¹ to which is attached the contact C rubbing
on the surface wing W of the armature A of the motor device. The screw 9, in
contact with the support U, serves as a common terminal for the magnet wind-
ing M and the resistance R. Y¹ is a counter-weight sufficient to raise the
armature A¹ from the unmagnetized core P. N and N are insulating pieces to
prevent the contact of armature A¹ with the core P. f is an adjusting screw to
limit the upward motion of A¹. The resistance R and the condenser K, together
with the resistance R¹ are used for the same purposes and connected in the same
manner as has already been elicited in connection with the mechanism of Figs. 1
and 2.
For use on continuous current circuits only, the form of winding mechanism
shewn in Fig. 6 may be simplified by suppressing the contacts C¹ D support I
and the resistance R.
It is obvious that with the arrangement the axis of the shaft S of the arma-
ture A, and the axis of the coil M must both lie in the same horizontal plane.
Figs. 5, 7 and 8, shew a simplified form of winding mechanism for use on con-
tinuous current circuits only. The contacts C¹ D, support I¹ and the resistance R
of the mechanism if Figs. 1 and 2 are suppressed. The contact C is now mounted
directly on the spring I and on the rotation of the armature A by the unwinding
of the main spring E, contact is established between C and D¹.
The details of these contacts are shewn in Fig. 5. The circuit of the magnet
winding M is closed when the contacts C and D touch one another. Thereupon
the contact C is at once brought into firm touch with the surface of the wing W
because of the magnetic attraction between the wing W and the spring I due to
the creation of a magnetic field of force by the magnet, some of the lines of the
interpolar space being closed through the path offered by the iron wing W and
the spring I.
The magnetic attraction between the electro-magnet and its armature A returns
the latter to or beyond the medial position, thus winding the main spring. At
the same time the circuit of the motor device is interrupted rapidly at the
contact C when this leaves the tip of the wing W. A condenser K in series with
a resistance R¹ and connected to the terminals of the magnet-winding M, as
shewn, is also used with this mechanism and practically avoids any sparking.
To anyone skilled in the art it is obvious that the contacts C, W may be
operated by an electro-magnet the winding of which is connected in series or
shunt with the winding M of the motor device.
We believe the idea of having the contacts operated by the magnetic attraction
of the winding magnet to be novel whether applied in the particular way described
or otherwise.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. Electrical winding mechanisms having a contact or contacts actuated by
the magnetic field of the electro-magnetic motor device or by the magnetic field
of an electro-magnet connected in series or shunt with the aforesaid motor
winding, substantially as herein described.

page_text: 2. Electrical winding mechanisms comprising a winding device actuated by
an electro-magnetic motor, circuit making and breaking contacts and the clock
mechanism as described and shewn in the accompanying drawings.
Dated this 25th day of June 1900.
:
THE BRITISH THOMSON-HOUSTON CO., LTD.,