IM- PROVEMENTS IN RELAYS FOR ELECTRIC TELEGRAPHS
Year: 1877

page_text: LETTERS PATENT to. Carl Hermann Gustav Risch, of 6, Brighton Villas,
Cranfield Road, Brockley, in the County of Kent, for the Invention of "IM-
PROVEMENTS IN RELAYS FOR ELECTRIC TELEGRAPHS."
Sealed the 8th September 1877, and dated the 26th June 1877..
PROVISIONAL SPECIFICATION left by the said Carl Hermann Gustav Risch
at the Office of the Commissioners of Patents on the 26th June 1877.
CARL HERMANN GUSTAV RISCH, of 6, Brighton Villas, Cranfield Road, Brockley,,
in the County of Kent. "IMPROVEMENTS IN RELAYS FOR ELECTRIC TELEGRAPHS."
This Invention relates to the construction of a relay for electric telegraphs of the
kind well known as Siemens' polarised relay, the object of my Invention being to
construct a relay of that kind in such a manner that it will readily follow the
varying positive or negative charges of a long land line or cable, making the
required contacts in accordance therewith. For this purpose I provide a relay
tongue having the form of a circle, or segment of a circle, mounted at its centre, so
that it can freely turn thereon, and I make it either a permanent magnet, or polarise
it by induction at its centre from a permanent or electro-magnet.
At and nearly in contact with the circumference of the circular or segmental
tongue, I fix the two poles of one electro-magnet or the four poles of two electro-
magnets, the coils of which are in connection with the line, arranging these poles
symmetrically, and making them adjustable nearer to or farther from the periphery
of the tongue. From the tongue an arm projects between two adjustable contacts
which are free to slide or shift to right or left together, and for that purpose they
are preferably both mounted on an arm free to oscillate.
When the electro-magnets are quiescent the induced magnetism of the tongue
induces opposite polarity in the magnets, the tongue taking such a position in
respect of them as is determined by the magnetic forces in action without the aid of
springs or other means of adjustment, and when the magnetic forces are varied by
a current or change of current transmitted by the line, the tongue changes its
position, and the arm projecting from it makes contact on one side or the other by

page_text: meeting one of the two contacts, which it pushes aside while it still remains in
contact with it, thus causing the other contact to follow it up, so that on a reversal
of current or change of potential the arm by a very small movement makes contact
on the other side.
Two tongues such as I have described above, of like or of opposite polarity, may a
be made to act in unison, either conjointly for the purpose of operating according to
such codes as the Morse code, or separately for operating according to such code as
the Steinheil code.
SPECIFICATION in pursuance of the conditious of the Letters Patent filed by
the said Carl Hermann Gustav Risch in the Great Seal Patent Office on the
24th December 1877.
CARL, HERMANN GUSTAV RISCH, of 6, Brighton Villas, Cranfield Road, Brockley,
in the County of Kent. “IMPROVEMENTS IN RELAYS FOR ELECTRIC TELEGRAPHS."
This Invention relates to the construction of a relay for, electric telegraphs of the
kind well known as Siemens' polarised relay, the object of my Invention being to
construct a relay of 'that kind in such a manner that it will readily follow 'the
varying positive or negative charges of a long land line or cable, making the required
contacts in accordance therewith. For this purpose I provide a relay tongue having
the form of a circle, or segment of a circle, mounted at its centre, so that it can
freely turn thereon, and I make it either a permanent magnet, or polarise it by
induction at its centre from a permanent or electro-magnet.
At and nearly in contact with the circumference of the circular or segmental
tongue I fix the two poles of one electro-magnet or the four poles of the two electro-
inagnets, the coils of which are in connection with the line, arranging these poles
synimetrically, and making them adjustable nearer to or farther from the periphery
of the tongue. From the tongue an arm projects between two adjustable contacts
which are free to slide or shift to riglit or left together, and for that purpose they.
are preferably mounted on an arun free to oscillate.
When the electro-magnets are quiescent the induced magnetism of the tongue
induces opposite polarity in the magnets, the tongue taking such a position in
respect of them as is determined by the magnetic forces in action without the aid
of springs or other means of adjustment, and when the magnetic, forces are varied
by a current or change of current transmitted by the line, the tongue changes its
position, and the arm projecting from it makes contact on one side or, the other, by
meeting one of the two contacts, which it pushes aside, while it still remains in
contact with it, thus causing the other contact to follow, it up, so that on a reversal of
current or change of potential the arm by a very small movement makes contact on
the other side.
Two tongues sucli as I have described above,. of like. or of opposite polarity, may
be made to act in unison, either conjointly for the purpose of operating according
to such codes as the Morse code, or separately for operating according to such codes
as the Steinheil code.
:

page_text: tongues may be permanently magnetic or have magnetism induced on them by the
proximity of the poles of a magnet M, or they may be temporarily magnetised by
the line current passing through a coil 5 surrounding the axis à, the one tongue T
being of opposite polarity to the other tongue T'. Four coils 1, 2, 3, and 4, arranged
symmetrically in reference to the axis a have their cores terminating in eccentric
caps, by turning which more or less round, the distance between them and the arcs
of the tongues can be adjusted. An arm A extends from the one tongue between
two contact screws 6 and 7, which are on the upper end of an insulated lever arm 8
that is mounted on a pivot 9 with a light spring behind it to give friction adjustable
by a screw nut on the pivot. The coils 1, 2, 3, 4, are connected to the line, so that'
a current arriving by it increases the magnetic force of the one pair, such as 1 and 4
and diminishes or reverses that of the other pair 2 and 3, whereupon the sector
tongues are caused to deflect to the right or left, as the case may be, and the arm A
makes contact with 6 or 7. When it makes such contact, as for example with 7, a
continuation or increase of current or a succession of long continued currents,
alternating with short reversals has the effect of pressing the arm A farther and
farther in the same direction, and the contact 7 against which it bears is thus moved
with the lever 8, bringing the other contact 6 along with it close behind the arm A,
so that on a sufficient reversal of current the arm makes contact on the other side.
By separating the axis a into two parts, each with its tongue provided with a
contact lever, such as 8, the relay may be employed for signalling, as for the code
known as the Steinheil code.
Fig. 3 shews the arrangement of a single sector tongue T, which may be of the
form shewn in Fig. 4, with two electro-magnets 1 and 2, and contacts 6 and 7 on a
lever, such as 8 in Fig. 1.
Figs. 5 and 6 shew other forms of double sector tongues operating with four electro
magnets..
For operating with relays of the kind above described, I prefer to employ a
sending key of the construction shewn in plan at Fig. 7, in side view at Fig. 8, and
in end view at Fig. 9. This key, to which I make no claim as part of my present
Invention, may be employed with advantage for operating when other relays are
used at the receiving station, as by its use the signals are rendered more decided and
free from tailing. The knob is divided into two parts, one on the main lever L¹,
and the other on a side lever L mounted on L' by an insulating pivot 6, and acted
on by a spring 7 so as to keep the two parts of the knob asunder, unless when
they are closed together by the hand of the operator when he is about to use the
key.
Until so closed the lever L connected to line by the spring 7 completes
circuit from the line to the relay for receiving signals. On closing. the knob this
circuit is broken, and the line is then put in circuit with the key lever L', which by
the screw 1 is in circuit with the zinc pole of the battery. On the back part of the
key lever L are mounted by pivots fand f¹, two side levers A and B, of which A
is in metallic contact with L, and B is insulated from it; A is drawn by a spring 8
on to the screw 3, which is connected to the zinc pole, and B is drawn by a spring 9
connected to earth on to the screw 2, connected to the copper pole. Thus when the
knob is closed the line is connected to the zinc, and earth to the copper pole. On
the lever L¹ are fixed two insulated brackets C and Z, connected respectively to
the copper and zinc poles, and having screws 4 and 5 so adjusted that they are
just clear of the front ends of the levers B and A, when their back ends rest on 2
and 3.
When the operator having closed the knob depresses it, the following changes of
connection take place:-Contact is first broken between 1 and Z, but the lever A
maintains connection of line and zinc, and 4 coming in contact with B makes con-
nection to earth. By farther depression of the key the contacts of A and B with 2
and 3 are broken, and then contact is made at C. In the ascent of the knob a
similar series of changes of circuit arc effected in reverse order, and thus in both
cases the line is discharged in the course of the key's movement, and the discharge
•

page_text: is followed up by an impulse of opposite sign to the previous charge, and this gives
the receiving instrument or relay a more decided action.
The period of discharge may be varied in duration by adjustment of the screws 4
and 5.
Having thus.described the nature of my Invention and in what manner the same
is to be performed, I claim, the. use of an electric telegraph relay, wherein one or
more tongues terminate in circular arcs presented towards poles of electro-magnets
having coils connected to the line, so arranged that without the aid of lateral springs
the tongues maintain a middle position, or are deflected to right or left by electric
impulses transmitted by the line, substantially as herein described.
In witness whereof, I, the said Carl Hermann Gustav Risch, have hereunto
set my hand and seal, this Twenty-second day of December, in the year
of our Lord One thousand eight hundred and seventy-seven..
C. H. G. RISCH. (L.S.)