IMPROVEMENTS IN MAGNETO-ELECTRIC APPARATUS FOR RAILWAY SIGNALLING
Year: 1880

page_text: LETTERS PATENT to Geminiano Zanni, of Holborn Viaduct, in the City of
London, Medical Electrician, for an Invention of " IMPROVEMENTS IN
MAGNETO-ELECTRIC APPARATUS FOR RAILWAY SIGNALLING."
PROVISIONAL SPECIFICATION left by the said Geminiano Zanni at the
Office of the Commissioners of Patents on the 2nd October 1880.
GEMINIANO ZANNI, of Holborn Viaduct, in the City of London, Medical
Electrician. "IMPROVEMENTS IN MAGNETO-ELECTRIC APPARATUS FOR RAILWAY
SIGNALLING."
This Invention relates to apparatus for signalling on railways by means of
magneto-electric currents.
In signalling on railways according to the well known "block" system for the
purpose of advising distant stations of the state of the lines between the signalling
and receiving stations, that is to say, whether there is a train on the line or whether
the line is clear, it is of the utmost importance that the signals should be speedily
conveyed and easily interpreted, and to attain these results electricity is now
generally utilized, various kinds of apparatus being employed for making the same
available, and such apparatus, broadly speaking, may be divided into two classes,
first, such as are operated by voltaic electricity, and secondly, such as are actuated
by means of magneto-electricity. The first-named class of apparatus have various
defects; for instance, effective batteries are somewhat costly in construction, and
in some cases consume expensive materials in their operation; they also demand a
considerable amount of attention, as they readily become inoperative from various
causes, such, for instance, as leakage between the battery-cells.
The second class of apparatus, viz., those actuated by magneto-electricity, being
more uniform and reliable in their action, are therefore much to be preferred, but
such apparatus as hitherto made have usually been very complicated in construction,
and they are therefore liable to get out of order, and some of them only give weak
and intermittent currents; furthermore, the proper handling of all electric apparatus
as hitherto constructed for the aforesaid purpose, usually requires a certain amount
of knowledge beyond that ordinarily met with in the persons who have to be
entrusted with their management.
The object of this Invention is to provide means whereby magneto-electric
currents may be successfully employed for signalling on railways, and the apparatus
which I employ is simple in construction, inexpensive, durable, and capable of
being handled with great facility, and an important feature of this Invention
consists in the fact that my apparatus will be at all times ready for use and certain

page_text: in its action; morcover, it yields a strong continuous current, and will thereby
readily overcome any leakage on the line.
According to my present Iuvention I produce the electric current by apparatus
constructed substantially in the manner set forth in the Specifications of my former
Letters Patent dated the 13th November, A.D. 1877, No. 4232, and 13th October,
A.D. 1871, No. 2721, and I provide this apparatus with an indicator, such as is
ordinarily used in railway signalling, and upon the dial of which a hand or index
moves to and fro when actuated by a suitable electric current, and thus indicates
the state of the line, that is to say, it is inclined on one side to indicate "line
clear," and on the other side to indicate "train on line.".
I also provide an electric bell of suitable construction which will ring when a
current is passing through the instrument so as to call the attention of the signal-
man or other person in charge to the signal or signals given by the indicator, that
is to say, the bell will sound simultaneously with the moving of the indicating
needle..
I further provide a switch of suitable construction which will allow the indicator
and bell to be cut out of the circuit when the apparatus is used as a sending
instrument, whilst at all other times the indicator and bell will be connected with
the line wire and the generator will be cut out, therefore it is in proper condition
to receive signals.
My Invention is especially applicable to the block or interlocking signalling
system now generally employed on railways, and I operate my apparatus as follows,
that is to say-At each of the two stations forming one circuit I place one of the said
apparatus, and connect them by means of a single conducting wire, the ends of
which are fixed to terminals on the said apparatus, carth wires being attached to
the other terminal of each of the said apparatus.
The current is generated by turning a crank or handle, and thereby rotating an
armature in the field of a permanent magnet. Now when it is desired to give a
signal the electric bell and indicator at the sending station are cut out of the
circuit by operating the switch, which preferably consists of a spring stud or studs
of ordinary construction in connection with suitable wires or the like. The nature
of the generated current depends of the direction in which the crank is rotated,
that is to say, when the said crank is turned from right to left the current may be
positive, and when the crank is turned from left to right it may be negative, or
vice versa, and the indicator being suitably arranged for the purpose the required
signal will be given at the receiving station, as the index will be caused to move
in one direction by a positive current, a negative current causing it to move in the
reverse direction.
As soon as the signal is given and the switch is released the apparatus used as a
sending instrument is ready to receive signals from the second station, and I am
thus enabled to give the signals required in the block or interlocking system by
means of one pair of very simple and inexpensive apparatus and a single con-
ducting wire.
I may also connect each apparatus to two stations in such manner that each
station can receive signals from one station (say the "up" station) whilst sending
signals to the other (viz., the "down" station).
Instead of using an indicator shewing the signals by means of a hand or pointer
moving on a dial I may use an indicator shewing the signals by means of flags or
otherwise, such an apparatus, for instance, as that described in the Specification of
my former Letters Patent, No. 3262, dated 2nd of November, A.D. 1872.
The magneto-electric apparatus and the indicator are combined in one case, and
the bell may be placed at the upper part of the indicator, so that the whole
apparatus will be very compact and will occupy but a small space, and I may
arrange two indicators and generators with their respective bells in one case so as
to have reciprocal lines.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Geminiano Zanni in the Great Seal Patent Office on the 2nd
April 1881.
GEMINIANO ZANNI, of Holborn Viaduct, in the City of London, Medical
Electrician. "IMPROVEMENTS IN MAGNETO-ELECTRIC APPARATUS FOR RAILWAY
SIGNALLING."
This Invention relates to apparatus for signalling on railways by means of
magneto-electric currents.
In signalling on railways according to the well known "block" system for
the purpose of sending information from one station to another respecting the
state of the traffic on the lines between these stations, so that it may be known
at the station which receives the signal whether there is a train on the line or
whether the line is clear, it is of the utmost importance that the signals should be
speedily conveyed and easily interpreted, and to attain these results electricity is
now generally utilized, various kinds of apparatus being employed for rendering
the same available. Such apparatus, broadly speaking, may be divided into two
classes, that is to say, first, the class of apparatus operated by voltaic electricity,
and secondly, the class of apparatus actuated by magneto-electricity or magnetic
currents. The first-named class of apparatus has various defects, for instance,
effective batteries are somewhat costly, and in most cases necessitate the use of
expensive acids and other materials; such batteries also require a considerable
amount of attention, as they frequently become inoperative through frost or from
various other causes, such, for instance, as leakage between the battery cells or
polarization. The second class of apparatus, namely, that which is actuated by
magneto-electricity, is however more uniform and reliable in its action, and is
therefore much to be preferred, but such apparatus as heretofore constructed has
usually been very complicated, and is therefore liable to get out of order; further-
more, in the said apparatus in many cases weak and intermittent currents only
are produced, and the proper handling or working of the said apparatus usually
requires a greater amount of knowledge than that ordinarily met with in the
persons who are entrusted with its management.
The object of this Invention is to provide means whereby magneto-electric
currents may be successfully utilized for signalling on railways, and for this
purpose I employ apparatus which is simple in construction, comparatively
inexpensive, durable, and capable of being handled with great facility, and an
important feature of this Invention consists in so constructing the said apparatus
that it will be at all times ready for use and certain in its action, and will yield
a strong continuous current, and therefore readily overcome any leakage in the
line-wire.
My Invention is illustrated in the accompanying Drawing, in which
Figure 1 is a front elevation of my improved railway signalling apparatus, and
Figure 2 is a rear elevation of the same with the back of the case removed.
Figure 3 is a front elevation of the apparatus with the front of the case and the
needle-dial removed, and
Figure 4 is an end elevation of the said apparatus with part of the case
removed.
Like letters indicate the same parts throughout the Drawing.
In carrying this Invention into practice, I employ for producing the magneto-
electric current apparatus constructed substantially similar to that described in the
Specification of my former Letters Patent, dated the 13th day of November, A.D.
1877, that is to say, I employ a single or permanent compound magnet a of the
ordinary horse-shoe form and a revolving armature b, whose spindle or axis
carries a disc or cylinder c upon which the springs d, d, rest. To impart the

page_text: requisite rotary motion to the said armature I arrange upon a shaft e a toothed
segment or rack f, which gears with a pinion on the spindle of the said armature.
This segment has a to-and-fro motion imparted to it by the handle g attached to
the shaft e on the outside of the case A, as shewn in Figures 1 and 4. In
combination with this current-producing mechanism I also provide my improved
apparatus with an indicator, such as is ordinarily used in railway signalling, and
upon the dial of this indicator a needle hand or index h moves to and fro; this
needle. is supported upon an axis or spindle h' provided with a polarized magnet h²
as heretofore, the said magnet, and consequently the needle, being caused to rock
by changing the polarity of the magnetic current passing through the line-wire,
this change of polarity being produced by turning the handle g in opposite
directions, as hereinafter described. The said needle or index will thus be caused
to indicate the state' of the line, that is to say, it will be inclined on one side. to
indicate "line clear," and on the other side to indicate "train on line." I also
provide the said apparatus with an electric bell or other sounder or alarm of
suitable construction which is in the same circuit as the needle h, and which
will sound when a current is passing through the instrument, and thus call the
attention of the signalman or other person in charge to the signal or signals given,
that is to say, the bell will sound simultaneously with the moving. of the indicating
needle h.
I further provide the said apparatus with a switch j of suitable construction,
which will allow the indicator and bell to be cut out of the circuit when the
apparatus is to be used as a sending instrument, whilst at all other times the
indicator and bell will be connected with the line wire and the generator (that is
to say, the magnet and armature) will be cut out, and the apparatus will be in the
proper condition to receive signals. This switch preferably consists of a spring
stud or button in connection with suitable wires or conductors.
In some
The magneto-electric generator and the indicator are combined in one case, and
the bell is preferably placed at the top of the said case, as shewn, so that the
whole apparatus will be very compact and will occupy but a small space.
cases I arrange two indicators and two current-generators with their respective
bells in one case to permit indications as to the state of both the up line and down
line on a railway.
My Invention is especially applicable to the block or interlocking signalling
system now generally employed on railways, and its operation is substantially as
follows, that is to say-At each of the two stations included in one circuit I place
an apparatus similar to that shewn in the Drawing, and connect the apparatus of
the two stations by means of a single conducting wire, the ends of which are fixed
to.a terminal in each apparatus, earth wires being attached to another terminal of
each of the said apparatus. When it is desired to give a signal the electric bell and
indicator at the sending station are cut out of the circuit by pushing in the
switch. Whilst the switch button is thus pressed inward, the crank or handle
is turned and rotates the armature b in the field of the permanent magnet a, thereby
producing a strong and continuous magnetic current which, passing through the
coils surrounding the magnet h² on the needle-spindle at the receiving station, 4
causes the said magnet and the needle to rock in one or the other direction
according to the polarity of the magnetic current generated, and the indicator
being suitably arranged for the purpose, the required signal will be given.
As soon as the signal is given and the switch is released, the apparatus used as
a sending instrument is ready to receive signals from the other station, and I am
thus enabled to give the signals required in the block or interlocking system by means
of one pair of very simple and coinparatively inexpensive instruments and a single
conducting wire. The generated current will differ in polarity, that is to say, will
be positive or negative, according to the direction in which the crank g is rotated,
and the connections may be such that when the said crank is turned from right to
left the current will be positive, and when the crank is turned from left to right it
will be negative (or vice versa).

page_text: To prevent any accidental displacement of the needle after it has been adjusted
either to "line clear" or "train on line," I prefer to make the upwardly extending
arm of the magnet h² of greater weight than the lower arm, so that when the
upper arm is caused to pass to either side of a vertical line through the axis of
the needle by the passage of a magnetic current through the line wire and the coils,
said arm will hold the needle in position until a reverse current is sent through
the said line wire. By this arrangement I am enabled to dispense with any current
in the line wire to retain the needle in position, as in the ordinary apparatus in
which galvanic or voltaic electricity is employed. Moreover, with my improved
apparatus it becomes impossible to change the position of the needle at the receiving
station if at the sending station the crank or handle g should be moved accidentally
or by inadvertence on the part of the operator (without actuating the switch) from
the position to which it was last turned, and should be again moved in the
same direction as that required to effect the last adjustment of the needle; in such
a case the ringing of the bell is all that will be effected at the receiving station,
as a reversal of the polarity of the current must ensue before there can be any
readjustment of the needle.
"
I in some cases connect each apparatus to two stations in such a manner that
cach station can receive signals from one station (say, the up" station) whilst
sending signals to the other (viz., the "down" station).
Instead of using an indicator shewing the signals by means of a hand needle or
pointer moving on a dial, I may use an indicator shewing the signals by means of
flags or otherwise, or an apparatus, for instance, such as that described in the
Specification of my former Letters Patent, No. 3262, dated 2nd of November, A.D.
1872.
Having thus fully described my said Invention, and the manner of performing
the same, I wish it understood that I am aware that electro-magnetic or dynamo-
electric apparatus may be used instead of or as a substitute for the magneto-electric
generator consisting of the permanent magnet and revolving armature in combina-
tion with the dials and bells for the purpose hereinabove stated, but this generator,
by reason of its simplicity, cheapness, and facility of operation, affords advantages
which could not be obtained by the use of electro-magnetic or dynamo-electric
apparatus, and I do not consider such apparatus to have any practical utility, or
claim the same for the purpose of my Invention, neither do I limit myself to or claim
the precise form or construction of any of the parts of the said apparatus as shewn
in the Drawing, or limit myself to any particular arrangement of the sounding and
indicating devices, but I claim,-
The magneto-electric apparatus, consisting of the generator in combination with
the switch and with the sounding and indicating devices for railway signalling
purposes, substantially as set forth.
In witness whereof, I, the said Geminiano Zanni, have hereunto set my hand
and seal, this Thirty first day of March, in the year of our Lord One
thousand eight hundred and eighty one.
G. ZANNI. (L.S.)