Improvements in Telegraph Apparatus.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Telegraph Apparatus.
We, MAICHE LIMITED, being a limited company formed to develop the inven-
tions of Louis Maiche, and having our registered office at 4, St. Mary Axe,
London, EC., do hereby declare the nature of this invention (as communicated
to us from abroad by Louis Maiche, Engineer, of 368, Rue St. Honoré, Paris)
to be as follows:-
This invention relates to improvements in telegraph apparatus which are prin-.
cipally applicable to circuits of considerable length where great sensitiveness
is necessary on account of the small current that is available; the apparatus may
however also be employed with advantage in other cases.
The main feature of the invention consists in causing the signalling current
to actuate at the receiving station a relay so arranged that the current only has
to overcome the inertia of the contact device for closing a local circuit in which
is included the recording instrument, the use of springs or gravity for breaking
the contact being entirely avoided, and the return motion of the contact device
being effected by a magnetic action produced by the closing of the local circuit.
Furthermore, in order to render the relay still more sensitive, the sticking of
the contact device is prevented by using mercury for the fixed contact while the
moving contact is constituted by a fine platinum point.
The relay is preferably constructed as follows for the above purpose.
The moving contact may be variously arranged, but preferably it consists of
a suspended coil, such as is employed in the well known syphon recorder, but
which in the present case carries, in lieu of such recorder, an arm with fine
platinum point projecting at right angles to the coil so as to oscillate by pre-
ference in a horizontal direction, and to make contact with a vertically arranged
mercury surface.
For providing such vertical contact surface, a small body of mercury is held
by capillary attraction in a horizontally placed glass tube, one end of which is
closed and has the conducting wire of the local circuit sealed into it, while the
other open end is presented to the platinum point of the moving contact so
that this on being deflected dips into the vertical surface of the mercury.
Although it is preferred to arrange the moveable contact to oscillate horizontally
and to make contact with a vertical mercury surface, it will be obvious that these
parts may be arranged to operate in any other position.
The coil of the moving contact is not acted upon by any springs, so that the
signalling current in deflecting the contact for closing the local circuit merely
has to overcome the inertia of the coil and arm with platinum point.
For effecting the return motion of the moving contact a magnetic device is
employed, so arranged in connection with the local circuit as to move the contact
back again, the moment the local circuit is closed. The local circuit includes
a battery and any suitable known form of recording instrument.
The magnetic device for the above purpose may consist of a second coil formed

page_text: of a few turns of stouter wire surrounding the coil of fine wire of the moving
contact, and connected at one end with the latter, while the other end is con-
nected to the one terminal of the recording instrument in the local circuit.
This second coil is so arranged that the current flows in the contrary direction
to that of the signalling current in the contact coil, so that as soon as contact
has been made and the local circuit closed by the action of the signalling current,
it will be immediately broken again by the magnetic action of the local current
in the second coil.
The above described construction of relay, being exceedingly sensitive, can
be worked at a very high rate of speed, and although it can be used with
advantage with the ordinary arrangement of long distance circuits, yet we prefer
to enable these to work with a corresponding greater rapidity for the above
purpose by effecting a considerable reduction of the retardation due to the
inductive capacity of the line in the following manner.
Referring to the accompanying diagrammatic drawing, there is combined with
the line wire L an induction coil consisting firstly of a low resistance coil A,
connected at one end to earth E and to the one pole of the battery B, while the
other end is connected to the lead of the signalling key D; secondly, there is
provided a high resistance coil C one end of which is connected to key D while
the other end is connected to the line wire L. The two coils are wound in the
same direction upon a bundle of soft iron wires, their resistances and number of
convolutions being so proportioned that the magnetic effect of the low resistance
coil considerably exceeds that of the high resistance coil, the result being that
the line is discharged with much greater rapidity by the action of the induction
coil than is possible with the usual arrangement.
Dated this 13th day of August 1898.
ABEL & IMRAY,
Agents for the Applicants.
Improvements in Telegraph Apparatus.
We, MAICHE LIMITED, being a limited company formed to develop the inven-
tions of Louis Maiche, and having our registered office at 4, St. Mary Axe,
London, E.C., do hereby declare the nature of this invention (as communicated
to us from abroad by Louis Maiche, Engineer, of 368, Rue St. Honoré, Paris),
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
This invention relates to improvements in telegraph apparatus which are prin-
cipally applicable to circuits of considerable length where great sensitiveness
is necessary on account of the small current that is available; the apparatus may
however also be employed with advantage in other cases.
The main feature of the invention consists in causing the signalling current
to actuate at the receiving station a relay so arranged that the current only has
to overcome the inertia of the contact device for closing a local circuit in which
is included the recording instrument, the use of springs or gravity for breaking
the conact being entirely avoided, and the return motion of the contact device
being effected by a magnetic action produced by the closing of the local circuit.
Furthermore, in order to render the relay still more sensitive, the sticking of
the contact device is prevented by using mercury for the fixed contact while the
moving contact is constituted by a fine platinum point.

page_text: The relay for the above purpose is preferably constructed as we will describe
with reference to the accompanying diagrammatic drawing.
The moving contact may be variously arranged, but preferably it consists of a
light frame D suspended between the limbs of a magnet A and carrying a coil B
such as is employed in the well known syphon recorder and which is included in
the main circuit L but which coil in the present case carries, in lieu of such
recorder, an arm C insulated from frame D with fine platinum point E projecting
at right angles to the coil so as to oscillate by preference in a horizontal direction,
and to make contact with a vertically arranged mercury surface F.
For providing such vertical contact surface, a small body of mercury F is held
by capillary attraction in a horizontally placed glass bulb G one end of which
is closed and has the conducting wire H of the local circuit sealed into it, while
the other open end is presented to the platinum point E of the moving contact C
so that this on being horizontally deflected penetrates into the vertical surface of
the mercury F. Although it is preferred to arrange the moveable contact to
oscillate horizontally and to make contact with a vertical mercury surface, it will
be obvious that these parts may be arranged to operate in any other position.
The coil B of the moving frame D and contact C E is not acted upon by any
springs, so that the signalling current from X in deflecting the contact for closing
the local circuit merely has to overcome the inertia of the light frame coils and
arm with platinum point.
For effecting the return motion of the moving contact, a magnetic device
is employed, so arranged in connection with the local circuit as to move the con-
tact back again, when the local circuit as closed. The local circuit includes a
battery I and any suitable known form of recording instrument J.
As shewn on the diagram the magnetic device for the above purpose consists
of a second coil K formed of a few turns of stouter wire upon the frame 1) and
connected at one end by the wire H with the mercury contact F while the other
end is connected by wire H to the one pole of the local battery I, the other pole
of which is connected by wire H2 with the one terminal of the recording instru-
ment J and the other terminal of this is connected by wire H³ with the arm C and
platinum contact E so that when this makes contact with the mercury F the local
circuit H H1 H2 H3 is closed. The second coil K is so arranged that the current
flows in the contrary direction, through it to that of the signalling current in
the thin wire coil B, so that as soon as contact has been made and the local
circuit closed by the action of the signalling current, it will be at once broken
again by the magnetic action of the local current in the second coil. The above
described construction of relay, being exceedingly sensitive, can be worked at a
very high rate of speed, and although it can be used with advantage with the
ordinary arrangement of long distance circuits, yet we prefer to enable these
to work with a corresponding greater rapidity for the above purpose by effecting a
considerable reduction of the retardation due to the inductive capacity of the
line in the following manner.
of
a
one
Referring to the diagrammatic drawing accompanying our Provisional Specifi-
cation there is combined with the line wire L an induction coil consisting firstly
at
low resistance coil A, connected
and
end to earth E
to the one pole of the battery B, while the other end is connected
to the lead of the signalling key D; secondly there is provided a
high resistance coil C one end of which is connected to key D while the other end
is connected to the line wire L. The two coils are wound upon a bundle of soft
iron wires, their resistances and number of convolutions being suitably pro-
portioned to the resistance and inductive capacity of the line.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
1. In a telegraph circuit, a relay wherein a coil, through which the signalling
current passes, is suspended in a magnetic field so as to be deflected on the passage

page_text: of a current thereby causing an arm connected in an insulated manner to the
coil to close a contact on a local circuit including the recording instrument, the
return motion of the coil and arm for breaking the local circuit being at once
effected by a second coil included in the local circuit substantially as described.
2. In a relay for a telegraph circuit, the combination of a coil through which
the line current passes, and which is suspended in a magnetic field, a contact
arm connected to the said coil in an insulated manner and adapted to make a
liquid contact on the passing of a line current, a local circuit connected to the
contact arm and to liquid contact and including a recording instrument, and a
coil included in the local circuit arranged in the said magnetic field and made
to act upon the contact arm so as to break the contact again as soon as it is
made, substantially as described.
3. The use, for the liquid contact referred to in the second claim, of a small
tube closed at one end and open at the other in which a body of mercury is
retained by capillary attraction, substantially as described.
4. In a relay for telegraph circuits, the combination of a coil B suspended in
a magnetic field and included in the signalling circuit, a contact arm C E making
contact with a mercury surface l' included in the local circuit on the deflection
of the coil B and a second coil K included in the local circuit and so arranged
as to bring the coil B and contact arm back into their original position immediately
on the closing of the local circuit, substantially as described.
5. In combination with a telegraph transmitter an induction coil of which the
low resistance winding is connected at one end to the earth and return connection
of the battery, and at the other end to the signalling key contact of the line wire
while the high resistance winding is included between the line wire and the
signalling key, substantially as described.
T
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