Improvements in Telegraph Receivers.
Year: 1890

page_text: Date of Application, 15th July, 1890
Complete Specification Left, 11th Apr., 1891-Accepted, 16th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in Telegraph Receivers.
I, CHARLES LANGDON-DAVIES of Mowbray House, Norfolk Street, Strand,
London, Electrician, do hereby declare the nature of this invention to be as
follows:-
:-
This invention has for its object improvements in telegraph receivers for vibratory
electric impulses and relates to instruments such as are described in the Specification
of my Patent No. 16616 in the year 1886 where the vibratory impulses in a line
bobbin impart movement to a reed and thereby open a local circuit which is
normally closed; the action being aided or reinforced by coils in the local circuit
which also influence the reed.
According to my present invention I render these instruments more sensitive and
efficient by constructing them in the manner shewn by the annexed drawings.
Figure 1 is a front elevation,
Figure 2 is a vertical section and
Figure 3 is an horizontal section.
a a are the bobbins connected with the line wire and which receive the vibratory
impulses. Preferably the connection is made by means of phonopores as is
The
described in my former Specification and without any through circuit.
bobbins are upon soft iron cores which are magnetised by a permanent magnet b.
The cores are furnished with pole pieces c c which influence a small armature d of
soft iron attached to a steel ribbon e. The ribbon e is strained to such a tension
that it vibrates in unison with the impulses received by the line bobbins and for
this purpose its ends are attached to levers ff adjustable by screws gg. A lever h
by a screw which it carries bears upon the ribbon e, it is held on by the light
spring h² and this spring can be strained more or less by a silk thread which can be
wound upon a pin i. is an insulated adjusting screw carrying a contact point
which is so set as to be in electric connection with the lever when the ribbon is at
rest but when the ribbon vibrates the lever leaves the contact point and a local
battery circuit is thereby opened. 11 are reinforcing coils when the instrument is
at rest the current of the local battery passes in these coils. The coils have soft
iron cores and these are magnetised by the permanent magnet b. The current in
the coils augments the magnetism induced by the permanent magnet; this is the
case both with the line coils and the reinforcing coils. m is an armature or relay
tongue which is attracted by the cores of the reinforcing coils, it pivots at m¹ and
a light spring m³ tends to withdraw it from the cores. The spring is adjustable by
winding a silk thread upon the pin n. When the armature or tongue m falls away
from the cores, (that is to say, when signal impulses enter the line bobbins) it closes
a relay circuit in which a signal instrument or indicator of any ordinary type is
included. Or in some cases the signals may be read by sound produced by the
armature or tongue in its movements.
The line bobbins, the reinforcing bobbins, the permanent magnet and the relay
tongue or armature are carried on a slab o of vulcanite or slate forming the back
of the instrument; whilst the steel ribbon and the parts connected therewith are
mounted upon a metallic ring frame p. The back is held to the frame by screws
passing through elongated holes and spring washers and by a screw passing through
the ring frame and entering a tapped hole in a lug fixed to the back slab of the
instrument. This screw serves to adjust the distance between the pole pieces and
To tune the strained ribbon to
the armature carried by the strained ribbon.
unison with the electric impulses on the line I employ a small mechanical telephone
and the thread of this instrument I connect with the metallic frame p.

page_text: In this receiving instrument in addition to the general arrangement of the parts
which is efficient and convenient, the application of the permanent magnet
magnetising the cores by induction is important and so is also the ribbon and the
means for straining the same, its armature and contact lever.
Figures 4, 5 and 6 show modifications to which I sometimes resort.
In Figure 4 there is no augmentor and the permanent magnet M serves as one
of the holders of the reed, which is then tuned by a single screw. LC is a single
line coil.
In Figure 5 a lever or finger in contact with the reed makes signals by opening
a relay or other local circuit.
In Figure 7 a local circuit is dispensed with.
A sonorous organ SO such as a profile or other bell, or a piece of strained
wood is struck by a hammer H. The normal rate of action of the hammer is
governed by a spring pulling it towards the stop S. When this rate differs
suitably from the normal rate of the reed, the blows struck by the hammer are
fewer and stronger and so they produce a greater effect upon the bell.
These instruments, in which no augmentor is used, are sufficient for short
circuits and many purposes where circumstances are favorable to electrical action,
and they are inexpensive.
But these devices can be used in conjunction with augmentors, and as modifica-
tions of the instrument shewn in the Figures 1, 2 and 3.
In the receiver, a single line coil and augmentor can sometimes be employed,
instead of two, and both for simplex and duplex working.
Dated this 15th day of July 1890.
C. LANGDON-DAVIES.
COMPLETE SPECIFICATION.
Improvements in Telegraph Receivers.
I, CHARLES LANGDON-DAVIES, of Mowbray House, Norfolk Street, Strand,
London, Electrician, 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 :-
This invention has for its object improvements in telegraph receivers for
vibratory electric impulses and relates to instruments such as are described in the
Specification of my Patent No. 16616 in the year 1886 where the vibratory
impulses in a line bobbin impart movement to a reed and thereby open a local
circuit which is normally closed; the action being aided or reinforced by coils in
the local circuit which also influence the reed.
According to my present invention I render these instruments more sensitive
and efficient by constructing them in the manner shewn by the annexed drawings.
Figure 1 is a front elevation,
Figure 2 is a section on the line 1-2 in Figure 1 and
Figure 3 is an horizontal section on the line 3-4 in Figure 1.
Figures 4, 5 and 6 shew modifications and
Figure 7 is a diagram of the circuits.
In Figures 1, 2 and 3, a a are the bobbins connected with the line wire and
which receive the vibratory impulses. Preferably the connection is made by means
of phonopores as is described in my former Specification and without any through
circuit. The bobbins are upon soft iron cores which are magnetised by a permanent
magnet b. The cores are furnished with pole pieces c c which influence a small
armatured of soft iron attached to a steel ribbon e. The ribbon e is strained to
such a tension that it vibrates in unison with the impulses received by the line
bobbins and for this purpose its ends are attached to levers ff adjustable by
screws gg. A lever h by a screw which it carries bears upon the ribbon it is
held on by the light spring and this spring can be strained more or less by a
€,

page_text: silk thread which can be wound upon a pin i. is an insulated adjusting screw
carrying a contact point which is so set as to be in electric connection with the
lever when the ribbon is at rest but when the ribbon vibrates the lever leaves the
contact point and a local battery circuit is thereby opened. I are reinforcing
coils when the instrument is at rest the current of the local battery passes in these
coils. The coils have soft iron cores and these are magnetised by the permanent
magnet b. The current in the coils augments or varies the magnetism induced by
the permanent magnet; this is the case both with the line coils and the reinforcing
coils. m is an armature or relay tongue which is attracted by the cores of the
reinforcing coils, it pivots at m' and a light spring m³ tends to withdraw it from the
cores.
When
the armature or tongue m falls away from the cores (that is to say, when signal
impulses enter the line bobbins) it closes a relay circuit in which a signal instrument
or indicator of any ordinary type is included. Or in some cases the signals may
be read by sound produced by the armature or tongue in its movements.
The spring is adjustable by winding a silk thread upon the pin n.
The line bobbins, the reinforcing bobbins, the permanent magnet and the relay
tongue or armature are carried on a slab o of vulcanite or slate forming the back
of the instrument; whilst the steel ribbon and the parts connected therewith are
mounted upon a metallic ring frame p. The back is held to the frame by screws
passing through elongated holes and spring washers and by a screw passing
through the ring frame and entering a tapped hole in a lug fixed to the back slab
of the instrument. This screw serves to adjust the distance between the pole
pieces and the armature carried by the strained ribbon without altering the relative
positions of the parts carried on the slab. To facilitate tuning the strained ribbon
to unison with the electric impulses on the line I employ a small mechanical
telephone and the thread of this instrument I connect with the metallic frame p.
In this receiving instrument in addition to the general arrangement of the parts
which is efficient, and convenient, the application of the permanent magnet
magnetising the cores by induction is important and so is also the ribbon and the
means for straining the same, its armature and contact lever.
In the diagram Figure 7 v v are wires forming part of an ordinary telegraph
line through which in addition to the ordinary signals, vibratory signals which do
not affect the ordinary telegraph instruments are transmitted; these vibratory
signals are interpreted by the instrument above described. wo wo are phonopores
which without metallic connection transmit the vibratory signals to the coils a a
Figure 1 and set the ribbon e in motion. x is a local battery, the circuit of which
when the ribbon e is at rest is completed through the lever h the screw k and the
coils l l. is another local battery the circuit of which is through the armature m
and the receiving instrument (of any ordinary type) z.
This circuit is closed and
a visible signal is given when the armature m is no longer held by the cores of the
coils. Or the connection may be made in the manner indicated in Figure 8.
One of the two line wires may be as is here shown simply an earth wire. One
line phonopore w will generally be sufficient, and when a phonoporic transmitter is
employed, the phonopore of the transmitter may be used to fulfil the functions
of wo as well as those of the transmitter.
Figures 4, 5 and 6 show modifications to which I sometimes resort.
In Figure 4 there is no augmentor or reinforcing coil and the permanent
magnet M serves as one of the holders of the reed, which is then tuned by a single
screw. LC is a single line coil corresponding to the coils a a in Figure 1.
In Figure 5 a lever or finger in contact with the reed makes signals by opening
a relay or other local circuit.
In Figure 6 a local circuit is dispensed with.
A sonorous organ SO such as a profile or other bell, or a piece of strained
wood is struck by a hammer H. The normal rate of action of the hammer is
governed by a spring pulling it towards the stop S. When this rate differs suitably
from the normal rate of the reed, the blows struck by the hammer are fewer and
stronger and so they produce a greater effect upon the bell.

page_text: These instruments, in which no augmentor is used, are sufficient for short circuits
and many purposes where circumstances are favourable to electrical action, and
they are inexpensive.
But these devices can be used in conjunction with augmentors, and as modifica-
tions of the instrument shewn in the Figures 1, 2 and 3.
In the receiver, a single line coil and augmentor can sometimes be employed,
instead of two, and both for simplex and duplex working.
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. In a telegraph receiver a coil on a core connected with a permanent magnet
and receiving vibratory impulses from a line wire and attracting intermittently
an armature on a supporting spring which as it oscillates opens a local battery
circuit.
2. In a telegraph receiver a coil receiving vibratory impulses from a line wire
and thereby magnetising a core and causing the same intermittently to attract an
armature on a strained metallic ribbon which as it oscillates opens the circuit of
other or reinforcing coils which also affect the magnetization of the core.
3. In a telegraph receiver the pair of coils a a on cores magnetised by the
magnet b which magnet also magnetises the cores of reinforcing coils // contained
in a local circuit; and influencing a relay armature m; the whole so arranged that
the armature m falls away and makes a signal or completes a local signal circuit
when the reinforcing circuit is opened by the vibration of a spring set in motion by
the intermittent attraction of the coils a a.
4. In a telegraph receiver, the metallic ring p carrying the strained ribbon e
and the parts connected therewith, the lever and contact screw k; and the slab o
carrying the parts a bland m the said slab and ring being adjustably connected
substantially as described.
Dated this 8th day of April 1891.
C. LANGDON-DAVIES.