Improvements in Recording Instruments for Electric Telegraphs.
Year: 1893

page_text: Date of Application, 2nd Nov., 1893
Complete Specification Left, 3rd Sept., 1894-Accepted, 13th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements in Recording Instruments for Electric Telegraphs.
I, ALEXANDER Muirhead, of No. 2 Prince's Street, in the City of West-
minster, Doctor of Science, Electrical Engineer, do hereby declare the nature of
this invention to be as follows:
My invention relates to that class of receiving instrument known as the siphon
recorder now generally used in conjunction with submarine telegraph cables.
The object of my present invention is to arrange or combine the component
parts of such an instrument that adjustments can be more readily effected than
hitherto and whereby the removal of the signal coil or other working parts of
the instrument is facilitated in case of accident, damage, or when otherwise
required.
The magnet forming part of the instrument is built up of a number of thin flat
horse-shoe shaped permanent steel magnets and is provided with adjustable pole-
pieces. The signal coil of rectangular shape is pivotted and is mounted together
with a fixed iron core on a brass or other suitable metallic plate connected to a rack
and pinion movement actuated by means of a milled-head screw or its equivalent
placed at the side of, or otherwise conveniently disposed on, the instrument. To
this latter plate is attached, by means of an arm, the bridge piece which carries
the aluminium frame or cradle of the siphon, the stretched wire, and part of the
apparatus for vibrating the siphon (consisting of a small electro-magnet with
hinged armature to which one end of the stretched wire is fastened). At one side
of or otherwise conveniently disposed on the framework of the instrument is fixed
the make-and-break or interruptor of the vibrator and a set of slide resistances for
the purpose of regulating the strength of the current flowing through the current
interruptor and the vibrator electro-magnets.
At another and accessible part
of the framework is the usual "sending" and "receiving" shunts to the signal
coil.
At the back of the instrument or in any other suitable position is mounted or
placed a small electro-motor connected to the driving wheel or paper roller either
through a series of friction wheels or by means of an india-rubber or equivalent
band. The speed of the paper roller is regulated either by varying the resistance
of the motor circuit or by varying the pressure between the surface of the motor
pulley and the friction wheel on which it rests.
The electro-motor I may generally prefer to use is one having permanent magnets
as field magnets.
Sometimes the signal coil may be suspended by means of a silk cord or fibre and
in order to keep it in position between the poles of the permanent magnet of the
recorder, two steel rods or axles working in agate holes or holes in hardened brass
plates are connected to the upper and lower horizontal parts of the coil.
The signal-coil is connected to the aluminium cradle which carries the siphon by
two fibres of silk or other similar material or of finely drawn suitable wire. These
two fibres or wires together with the stretched platinum wire or phosphor-bronze
strip on which the aluminium cradle is fastened give directive force to the coil.
When the coil is connected to the aluminium cradle by means of metallic wires
the latter may in some cases be coiled up into a short length of very fine spiral at
the extremities.
Sometimes the rectangular coil may be wound on an iron frame or strips of iron
may be attached to the upper and lower parts only of the coil to give additional

page_text: The ink box into which the siphon dips is adjustable, being supported on a pillar
provided with rack and pinion movement or other suitable means.
Dated this 2nd day of November 1893.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicant.
Improvements in Recording Instruments for Electric Telegraphs.
I, ALEXANDER MUIRHEAD, of No. 2 Prince's Street, in the City of West-
minster, Doctor of Science, Electrical Engineer, 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 relates to that form of receiving instrument known as the siphou
recorder now generally used in connection with submarine cables.
The object of my present invention is to arrange or combine the component
parts of such an instrument that the various adjustments of it can be more readily
effected than hitherto and so that the signal coil and other working parts of the
instrument can be more quickly removed in case of accident, damage, or when
otherwise required...
My invention is illustrated in the accompanying drawings.
Figures 1 and 2 are respectively front and side elevations of a recording
instrument made according to my invention.
Figure 3 is a front elevation and Figures 4 and 5 the two side elevations of the
bridge and suspension piece shown detached from the instrument.
The magnet M forming part of the instrument is built up of a number of thin
flat horse-shoe shaped permanent steel magnets and is provided with adjustable
pole-pieces N, S. The signal coil of rectangular shape is either pivotted or
suspended by fibres and is mounted together with a fixed iron core J on a brass or
other suitable metallic plate l' affixed to a rack R with which a pinion, operated
by a milled head screw H, engages. To the plate P an arm A is attached which
carries the bridge piece B. Across such bridge piece B a wire or fibre which
carries the aluminium frame or cradle of the siphon is stretched. For the sake of
clearness these parts are omitted from the present drawings but they, as well as the
other parts of the vibrating system are like those described in the Specification of
Letters Patent No. 3,413 dated 15th February 1893 granted to me jointly with
Robert Henry Edgar. E, E represents the electro magnet mounted on the bridge
piece B, X its hinged armature to which one end of the stretched wire carrying
the siphon is attached, and V, V the make-and-break or circuit interruptor of the
vibrator. Y is a set of slide resistances for the purpose of regulating the strength
of the current flowing through the coils V, V and E E. At another and accessible
part of the framework are placed the usual "sending" and "receiving" shunts to
the signal coil. The ink box G, into which the siphon dips, is adjustable. The
box is carried by an arm K attached to a pillar L provided with a rack with which
a pinion, operated by a milled head screw O, engages.
The signal coil is connected to the aluminium cradle which carries the siphon by
two fibres of silk or other similar material or by two finely drawn wires of some
suitable material. These two fibres or wires together with the stretched platinum
wire or phosphor bronze strip to which the aluminium cradle is fastened give the
necessary directive force to the coil as described in the said prior Specification.
According to my present invention when the coil is connected to the aluminium
cradle by means of metallic wires the latter may in some cases be shortened by
coiling them into very fiue spirals at their extremities.

page_text: Sometimes strips of iron may be attached to the upper and lower parts of the
coil to give additional directive force.
On the top of the instrument or in any other suitable position is mounted or
supported an electro motor Z, Z the armature of which is connected to the paper
roller by a band of india rubber or other suitable material and friction wheels or
by a series of friction wheels without a band. The drawings show a pulley Q
attached to the shaft T of the motor. The said pulley is connected by a band to
another one U to drive the paper roller W through the intermediary of an ebonite or
other suitable friction wheel F. The speed of the paper roller is regulated either
by varying the resistance in the battery circuit of the motor or (when a series of
friction wheels is employed) by varying the pressure between the surface of the
motor pulley and the friction wheel on which it rests.
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. A siphon recorder having its bridge and suspension piece and other working
parts adjustable and removable substantially as set forth.
2. In a siphon recording apparatus attaching the suspension piece to a rack and
pinion movement or any equivalent mechanical device in such manner that it can
readily be worked by means of a regulating screw from the front or the operating
side of the instrument.
3. The combination and arrangement of parts constituting my improved recording
instrument for electric telegraphs substantially as set forth.
Dated this 3rd day of September 1894.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicant.