Improvements in Apparatus for Transmitting Telegraphic Indicating and other Analogous Signals or Movements by Means of Electric Currents.
Year: 1893

page_text: Date of Application, 14th July, 1893
Complete Specification Left, 16th Apr., 1894-Accepted, 19th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Transmitting Telegraphic Indicating
and other Analogous Signals or Movements by Means of Electric
Currents.
We, ANDREW BETTS BROWN, and WILLIAM FALCONER KING, both of
Rosebank Electric Works, Edinburgh, North Britain, Engineers, do hereby
declare the nature of this invention to be as follows:—
Our said invention relates to telegraphic indicating and other analogous apparatus
in which signals or movements are transmitted through a greater or less distance by
meaus of electric currents operating on an electro-magnet or magnets which is or
are caused to operate on an escapement wheel or other analogous device, causing it
to turn with its pointer attached to the message or signal which is required to be
transmitted; and it has for its object to apply to such apparatus devices for
ensuring the accurate correspondence of the sending and receiving instruments.
In the simple case taken for example in which the movement of the receiving
instrument is obtained by an ordinary escapement and escapement wheel, such as is
employed in the well-known A. B. C telegraph instruments of Wheatstone, the
receiving instrument sometimes gets out of correspondence with the sending instru-
ment owing to weak electrical power or other defect, and has to be re-set by hand
and by previous arrangement between the sender and receiver. The object of our
invention is to effect this re-setting automatically and once or twice during each
revolution of the indicator.
In carrying out our invention a correcting device is arranged to act at one, two,
or more definite positions. One or more springs or weights or an equivalent
appliance is arranged to act on the receiving instrument to move its pointer into
one or more definite positions whenever it is let go after being moved therefrom in
either direction. The sending instrument is arranged to release the receiving
instrument at these predetermined positions when the springs or weights before
mentioned cause the receiving instrument to move to the predetermined position or
positions and set the receiving and sending instruments into exact correspondence.
A second part of our invention consists of an arrangement of electro-magnets to
cause the receiving pointer to revolve in either direction according to the direction
in which the sending instrument is revolved. In the usual instruments of this step-
by-step class the pointer of the receiving instrument revolves always in one direction.
For some uses to which such instruments may be applied it is desirable that the
receiving instrument should move in either direction and follow the movement of
the sending instrument in whichever direction the latter is turned. This is notably
the case in an instrument for indicating the position of a ship's rudder at a distance
from the rudder. To effect this we fix on the spindle of the receiving instrument,
which also carries the indicating pointer, a wheel having V-shaped teeth of any
convenient number. Three or more electro-magnets are arranged to cause this
wheel to revolve by means of V-shaped pieces of metal attached to the armatures of
the electro magnets. These V-shaped pieces on the armatures are arranged round
the toothed wheel at such distances apart that when No. 1 V-piece is drawn into
full gear with one tooth of the wheel No. 2 V-piece is one third of the pitch of the
teeth of the wheel in advance of the centre of the tooth space to which it is opposite.
Similarly No. 3 V-piece is one third of the pitch behind the centre of its nearest
space, or, what is the same thing, it is two thirds of the pitch in advance of the next

page_text: nearest space. By this arrangement if the three electro-magnets are thrown into
action in succession in the order No. 1, No. 2, No. 3 the wheel will revolve in one
direction, but if the electro-magnets are thrown into action in succession in the
order 3, 2, 1, the wheel will revolve in the opposite direction.
This order of sending the necessary currents is evidently easily effected in the
sending instrument by having a succession of studs 1, 2, 3, 1, 2, 3, etc., each con-
nected by a wire to its appropriate electro-magnet, and when the connecting piece
of the sending instrument which completes the electrical circuit moves in one
direction it affects the electro-magnets in the succession of 1, 2, 3, 1 etc. and it is
evident that when this is moved in the opposite direction it affects the magnets in
the succession of 3, 2, 1, 3 etc., causing the receiving instrument to follow the move-
ments of the sending instrument in whichever direction it is moved.
We also apply to this form the correcting device described in the first part of the
Specification.
Dated this 13th day of July 1893.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicants' Agents.
Improvements in Apparatus for Transmitting Telegraphic Indicating
and other Analogous Signals or Movements by Means of Electric
Currents.
We, ANDREW BETTS BROWN, and WILLIAM FALCONER KING, both of
Rosebank Electric Works Edinburgh, North Britain, Engineers, 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 :-
Our said invention relates to telegraphic indicating and other analogous apparatus
in which signals or movements are transmitted through a greater or less distance by
means of electric currents operating on an electro-magnet or magnets which is or
are caused to operate on an escapement wheel or other analogous device, causing it
to turn with its pointer attached to the message or signal which is required to be
transmitted; and it has for its object to apply to such apparatus devices for
ensuring the accurate correspondence of the sending and receiving instruments.
In order that our invention may be properly understood and readily carried into
effect we have hereunto appended two explanatory sheets of drawings in the
several figures of which corresponding parts are marked with the same letters of
reference.
Figure 1 is a plan of the sending instrument.
Figure 2 is a section of the sending instrument.
Figure 3 is a plan of the receiving instrument with the dial removed.
In the simple case taken for example in which the movement of the receiving
instrument is obtained by an ordinary escapement and escapement wheel such as is
employed in the well known A. B. C. telegraph instruments of Wheatstone, the
receiving instrument sometimes gets out of correspondence with the sending instru-
ment owing to weak electrical power or other defect, and has to be re-set by hand
and by previous arrangement between the sender and receiver. The object of our
invention is to effect this re-setting automatically and once or twice during each
revolution of the indicator.
In carrying out our invention a correcting device is arranged to act at one, two,
or more definite positions. One or more springs or weights, or an equivalent
appliance is arranged to act on the receiving instrument to move its pointer into one
or more definite positions whenever it is let go after being moved therefrom in

page_text: either direction. The sending instrument is arranged to release the receiving
instrument at these predetermined positions when the springs or weights before
mentioned cause the receiving instrument to move to the predetermined position or
positions and set the receiving and sending instruments into exact correspondence.
A second part of our invention consists of an arrangement of electro-magnets to
cause the receiving pointer to revolve in either direction according to the direction
in which the sending instrument is revolved. In the usual instruments of this
step-by-step class the pointer of the receiving instrument revolves always in one
direction. For some uses to which such instruments may be applied it is desirable
that the receiving instrument should move in either direction and follow the
movement of the sending instrument in whichever direction the latter is turned.
This is notably the case in an instrument for indicating the position of a ship's
rudder at a distance from the rudder. To effect this we fix on the spindle a of the
receiving instrument, which also carries the indicating pointer ba wheel c having
V-shaped teeth of any convenient number. Three or more electro-magnets d, e, f,
are arranged to cause this wheel to revolve by means of V-shaped pieces of
metal 1, 2, 3 attached to the armature of the electro-magnets. These V-shaped
pieces on the armatures are arranged round the toothed wheel at such distances
apart that when No. 1 V-piece is drawn into full gear with one tooth of the wheel,
No. 2 V-piece is one third of the pitch of the teeth of the wheel in advance of the
centre of the tooth space to which it is opposite. Simultaneously No. 3 V-piece is
one-third of the pitch behind the centre of its nearest space, or, what is the same
thing, it is two-thirds of the pitch in advance of the next nearest space. By this
arrangement if the three electro-maguets are thrown into action in succession in
the order No. 1, No. 2, No. 3, the wheel will revolve in one direction, but if the
electro-magnets are thrown into action in succession in the order 3, 2, 1, the wheel
will revolve in the opposite direction.
This order of sending the necessary currents is evidently easily effected in the
sending instrument by having a succession of studs 1, 2, 3, 1, 2, 3, etc., each
connected by a wire to its appropriate electro-magnet, and when the connecting
piece 9 of the sending instrument which completes the electrical circuit moves
in one direction it completes the circuits of the electro-magnets in the
succession 1, 2, 3, 1, etc., and it is evident that when this is moved in the opposite
direction it completes the circuits of the magnets in the succession of 3, 2, 1, 3, etc.,
causing the receiving instrument to follow the movements of the sending instrument
in whichever direction it is moved.
In order to ensure accurate correspondence of the indicators of the sending and
receiving instruments we provide one stud x not connected by wire with any of the
electro-magnets, so that when the connecting piece 9 is on this stud none of the
circuits of the electro-magnets is made, and all the V-pieces are disengaged from
the tooth wheel. On the spindle carrying the indicating pointer there is a crank h,
with light springs i, k pulling it to each side. These springs will, when none of
the V-pieces are in gear with the tooth wheel, draw the pointer to the zero position.
Thus whenever the connecting piece g of the sending instrument is on the stud a
the pointer of the receiving instrument will be brought to zero, and the two
instruments will be in correspondence.
In cases where the indicators of the sending and receiving instruments are to
make a complete revolution there may be a second stud r at the bottom of the
sending instrument not connected by wires to any of the electro-magnets. In this
case the pointers of the two instruments will be automatically brought into
correspondence twice during a revolution.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
The arrangement of springs or equivalent appliance by which the pointers of
the receiving and sending instruments are automatically brought into correspondence

page_text: once or twice during each revolution of the indicator in combination with a step-
by-step receiving instrument substantially as hereinbefore described.
Dated this 14th day of April 1894.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicants' Agents.