IMPROVEMENTS IN ELECTRIC APPARATUS FOR TRAIN SIGNALLING ON RAILWAYS.
Year: 1879

page_text: LETTERS PATENT to Edward Tyer, of No. 4, Old Street, Finsbury, in the County
of Middlesex, for the Invention of "IMPROVEMENTS IN ELECTRIC APPARATUS
FOR TRAIN SIGNALLING ON RAILWAYS.
Sealed the 30th May 1879, and dated the 17th March 1879.
PROVISIONAL SPECIFICATION left by the said Edward Tyer at the Office
of the Commissioners of Patents on the 17th March 1879.
EDWARD TYER, of No. 4, Old Street, Finsbury, in the County of Middlesex. " IM-
PROVEMENTS IN ELECTRIC APPARATUS FOR TRAIN SIGNALLING ON RAILWAYS."
In the Specifications to Patents granted to me on the 29th November 1861, No.
3015, the 21st May 1873, No. 1845, and the 23rd March 1874, No. 1013, I
described, among other matters, certain instruments for train signalling on railways,
in which instruments commutators were employed for effecting the transmission
and reception of signals by including certain of the conductors in the battery circuit
and excluding others, and armatures of circular and cylindrical form were acted on
by electro-magnets so as to move the signal indices or pointers. My present Inven-
tion relates to improvements in the construction and arrangement of armatures and
commutators for the purposes mentioned, and in the combinations of the commu-
tators and their operating handles with indices and moveable screens and signals
whereby the condition of the traffic on the railway line or lines is more clearly and
fully indicated and governed. In forming the cylindrical armatures above referred
to I provide a thin cylindrical shell of soft iron, which is cut in halves, and these
halves are fixed on the circumference of a non-magnetic disc, so as to complete the
At these cuts I
cylinder all but the narrow cuts separating the two half shells.
notch out middle portions of the cylindrical half shells so that at the intervals
separating them they each present two narrow tongue pieces nearly meeting one
another. The armature being polarised by two magnetic poles, as described in the
Specifications referred to, the absence of metal between these tongue pieces has the
effect of making the armature turn partly round on its axis with considerable force
when the other magnet of the instrument is excited by passage of a current through
its coils. According to another construction, instead of making the armature of
cylindrical shape, I make it consist of two thin pieces of iron, each shaped some-
what like a double anchor, consisting of two circular arcs of nearly 180° each not
quite meeting at their extremities where they are narrowed. The two semi-circular
...ת
1031

page_text: arcs are united by a cross bar forming a diameter. Two of these anchor pieces are
fixed on opposite ends of a non-magnetic boss, and into the space between them
project the poles of the magnets which act on them. Thus the force on each side is
balanced and no endways strain is thrown on the bearings of the axis on which the
armature is mounted. The commutator which I employ for the train signalling
instruments consists of a disc of non conducting material which can be turned
round into various positions. On the face of this disc are fixed certain metallic
plates, and facing these, but not touching them, are a number of contact springs.
The commutator disc besides being capable of being turned on its axis can be
pushed inwards by the hand of the operator in opposition to a spring, so as to bring
its plates in contact with the springs above mentioned. Thus when the operator
desires to send or receive a signal, he turns the axis of the commutator disc into
such a position that the plates on its face are properly disposed to make the desired
contacts, and he then pushes the commutator forwards so as to bring its plates in
contact with the springs, thus forming the required connections between some of
the conductors and breaking the connections of others. By this arrangement
the objectionable rubbing of the contacts over the face of the disc is avoided, the
partial revolution of the disc being always effected when it is not in contact with
the springs. In order to prevent the possibility of turning the commutator while
it is in contact with the springs, a pawl or stop may be provided which is free from
the commutator disc when the latter is in its back position, but which acts as a
detent, preventing it from being turned when in its forward position. In order to
determine the attitude into which the commutator is turned before making contact
the front of the disc has suitable marks on it which are seen by the operator through
a glass in the case of the instrument in the usual way. For example, in one of the
simplest forms of signalling instrument the commutator disc in one attitude will
present through the glass a white ground with such words as "line clear" on it;
in another attitude it will present a red ground with such words as "train on line,'
or "line closed." In many cases where the instruments are used at a station or
goods yard, the passage of successive trains has to be permitted, and it is then of
advantage that the operator should know how many trains he has passed. The
disc therefore may be made with successive divisions, numbered in order, so that
after each movement the number presented by it indicates the number of trains
that have passed. Instead of marking these numbers or successive divisions of the
commutator disc, they may be marked on a separate disc mounted on the same
axis and acted on by a pawl, so that at each movement of the commutator in the
one direction a fresh number is presented on the disc, while the commutator disc
itself shews only the usual signals. I effect an interlocking of the cominutator disc
with the main signals in the following manner :-When the disc is turned from the
attitude marked "line clear" to the attitude shewing "line closed," a screen is
caused to come in front of the commutator disc shewing "train on line." By this
movement of the screen a detent is engaged with a stop on the commutator so that
the latter cannot now be moved. The screen is however connected by a wire to
the lever which works the main signal, so that when this signal is raised to the
'danger" attitude the screen is withdrawn, the detent worked by it is released, and
the commutator disc now shewing "line closed" can thereafter be moved to "line
clear," whereupon the like succession of operations can be repeated. In arranging
commutators as above described I provide on their peripheries teeth, or cogs, or
recesses with which engages a spring pawl, so that the commutator on being turned
one division is held steady by the dropping in of the pawl, and the operator by
feeling the resistance of the pawl is enabled to turn the commutator with more
certainty to the desired attitude. The pawl referred to is in many cases arranged
with advantage so as to form an absolute stop which has to be released by the
action of a lever or button before the commutator can be turned.
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Tyer in the Great Seal Patent Office on the 13th
September 1879.
EDWARD TYER, of No. 4, Old Street, Finsbury, in the County of Middlesex,
"IMPROVEMENTS IN ELECTRIC APPARATUS FOR TRAIN SIGNALLING ON RAILWAYS."
In the Specifications to Patents granted to me on the 29th November 1861,
No. 3015, the 21st May 1873, No. 1845, and the 23rd March 1874, No. 1013, I
described among other matters certain instruments for train signalling on railways,
in which instruments commutators were employed for effecting the transmission and
reception of signals by including certain of the conductors in the battery circuit and
excluding others, and armatures of circular and cylindrical form were acted on by
clectro magnets so as to move the signal indices or pointers. My present Invention
relates to improvements in the construction and arrangement of armatures and
commutators for the purposes mentioned, and in the combinations of the com-
mutators and their operating handles with indices and moveable screens and signals,
whereby the condition of the traffic on the railway line or lines is more clearly and
fully indicated and governed. In forming the cylindrical armatures above referred
to I provide a thin cylindrical shell of soft iron which is cut in halves, and these
halves are fixed on the circumference of a non-magnetic disc so as to complete the
cylinder all but the narrow cuts separating the two half shells. At these cuts I
notch out middle portions of the cylindrical half shells so that at the intervals
separating them they each present two narrow tongue pieces nearly meeting one
another. The armature being polarised by two magnetic poles as described in the
Specifications referred to, the absence of metal between these tongue pieces has the
effect of making the armature turn partly round on its axis with considerable force,
when the other magnet of the instrument is excited by passage of a current through
its coils. According to another construction, instead of making the armature of
cylindrical shape I make it consist of two thin pieces of iron, each shaped somewhat
like a double anchor, consisting of two circular ares of nearly 180° each, not quite
meeting at their extremities where they are narrowed. The two semi-circular ares
are united by a cross bar forming a diameter. Two of these anchor pieces are fixed
on opposite ends of a non-magnetic boss, and into the space between them project
the poles of the magnets which act on them. Thus the force on each side is
balanced and no endways strain is thrown on the bearings of the axis on which the
armature is mounted. The commutator which I employ for the train signalling
instruments consists of a disc of non-conducting material which can be turned
round into various positions. On the face of this disc are fixed certain metallic
plates, and facing these, but not touching them, are a number of contact springs.
The commutator disc besides being capable of being turned on its axis can be
pushed inwards by the hand of the operator in opposition to a spring, so as to bring
its plates in contact with the springs above mentioned. Thus when the operator
desires to send or receive a signal he turns the axis of the cominutator disc into
such a position that the plates on its face are properly disposed to make the desired
contacts, and he then pushes the commutator forwards so as to bring its plates in
contact with the springs, thus forming the required connections between some of
the conductors and breaking the connections of others. By this arrangement the
objectionable rubbing of the contacts over the face of the disc is avoided, the partial
revolution of the disc being always effected when it is not in contact with the
springs. In order to prevent the possibility of turning the commutator while it is
in contact with the springs a pawl or stop may be provided which is free from the
commutator disc when the latter is in its back position but which acts as a detent
preventing it from being turned when in its forward position. In order to determine
the attitude into which the commutator is turned before making contact, the front

page_text: of the disc has suitable marks on it which are seen by the operator through a glass
in the case of the instrument in the usual way. For example, in one of the simplest
forms of signalling instrument, the commutator disc in one attitude will present
through the glass a white ground with such words as "line clear" on it, in another
attitude it will present a red ground with such words as "train on line" or "linc
closed." In many cases where the instruments are used at a station or goods yard
the passage of successive trains has to be permitted, and it is then of advantage
that the operator should know how many trains he has passed. The disc therefore
may be made with successive divisions numbered in order, so that after each move-
ment the number presented by it indicates the number of trains that have passed.
Instead of marking these numbers on successive divisions of the commutator disc
they may be marked on a separate disc mounted on the same axis and acted
on by a pawl, so that at each movement of the commutator in the one direction, a
fresh number is presented on the one disc while the commutator disc itself shews
only the usual signals. I effect an interlocking of the commutator disc with the
main signals in the following manner :-When the disc is turned from the attitude
marked "line clear" to the attitude shewing "line closed," a screen is caused to
come in front of the commutator disc shewing "train on line." By this movement
of the screen a detent is engaged with a stop on the commutator, so that the latter
cannot now be moved. The screen is however connected by a wire to the lever
which works the main signal, so that when this signal is raised to the "danger
attitude the screen is withdrawn, the detent worked by it is released and the com-
mutator disc now shewing "line closed" can thereafter be moved to "line clear,"
whereupon the like succession of operations can be repeated. In arranging the
commutators as above described I provide on their peripheries teeth or cogs, or
recesses with which engages a spring pawl, so that the commutator on being turned
one division is held steady by the dropping in of the pawl, and the operator by
feeling the resistance of the pawl is enabled to turn the commutator with more
certainty to the desired attitude. The pawl referred to is in many cases arranged
with advantage so as to form an absolute stop which has to be released by the
action of a lever or button before the commutator can be turned.
DESCRIPTION OF THE DRAWINGS.
"
Fig. 1 is a front view, and Fig. 2 a side view of a cylindrical armature of the
kind described in the Specifications above referred to, modified according to the
present Invention. The two semicylindrical pieces A, A, of thin soft iron are fixed
on the periphery of the nonmagnetic disc B, and at their edges which do not quite
meet, they are notched out in the middle so as to leave in each case two narrow
tongues a, a; Fig. 3 is a front view, and Fig. 4 a side view of another form of
armature according to the present Invention. It consists of two pieces of thin
soft iron D, D, each of the form of a double anchor or consisting of two nearly
semicircular segments united by a cross bar or diameter. The semicircular parts
which do not quite meet are narrowed at their adjacent extremities d, d. The two
double anchor pieces D, D, are fixed on the ends of a non magnetic boss E on an
axis e.
The poles F of the magnets which act on the armature protrude into the
space between the two parts D, D, attracting or repelling them equally in both
directions so that there is no pressure on the pivots of the axis e. Fig. 5 is a front
view of one of the block signalling instruments according to my Invention; Fig. 5ª
shews the hinged door forming the front of the lower part of the instrument folded
back to shew the commutator inside; Fig. 5b is a section on the line X, X, of
Fig. 6, which is a vertical section through the axis of the commutator; Fig. 6a
shews the relative positions of the commutator and contact springs, the former
having been turned to the opposite position to that shewn at Fig. 5º. A is a disc
of non conducting material such as ebonite, fixed on a square spindle a that is fitted
to slide within a sleeve B, and is pressed forwards by a spring 6 butting against
a collar on the spindle. The sleeve B is fitted in a socket C fixed on the door of

page_text: the instrument so that it can be turned partly round by a nob D, the spindle a,
and disc A, and another disc d, which is fixed on the sleeve, turning with it. A
spring lever L having inclined notches engaging with a pin on the disc d limits
the turning movement of the sleeve and disc and determines it to the full extent
in each direction as more clearly seen at Fig. 5b. On the face of the disc A are
fixed pieces of metal arranged in relation to the spring contacts E at the back of
the casing, so that in the two attitudes to which the disc can be turned, different
pairs of these contacts are electrically connected through the conductors on the
face of the disc in the usual manner; f is a tooth projecting from the disc A, and
Fa fixed stop in such a position that when the tooth f is in the plane of the stop
F the latter prevents the disc from being: turned; G is a screen fixed on the
sleeve B, and presenting through a glass Han indication in its one attitude such
as "line clear," and in its other attitude "line blocked," or such other indications
as may be required for the special use of the instrument. In operating with this
instrument the door of the casing being closed, the commutator disc A is kept by
the spring away from the contacts E, so that it can by turning the nob D be
turned partly round so far as the stops of the lever L permit without touching or
rubbing on the contacts E. When it is turned to the desired attitude as shewn by
the indication of the screen through the glass H, the operator pressing on the nob
end a¹ of the spindle a pushes the spindle in opposition to the spring b, and brings
the face of the disc up against the contact springs E so as to make the desired
electrical connections between them. Whilst, the disc is so pressed against the
contacts it cannot be turned because the tooth f is on the one side or other of the
stop F.
When the pressure on the nob a' is relieved, the spindle a springs back,
moving the disc clear from the contacts E, and the tooth f being now clear of the
stop F the disc can be turned. In the other instruments which I am about to
describe, the arrangements of the commutator spindle sliding in a turning sleeve
and pressed forward by a spring, and the stops so disposed that the commutator
disc cannot be turned round while it is bearing on the contacts are employed, but
as the parts for this purpose are similar to those which I have already described
and are marked by letters corresponding with those in Figs. 5, 5ª, 5b, 6 and 6ª, I
need not repeat in each case their description.
Instead of arranging the commutator to be turned for bringing its conducting
plates into proper position relative to the contacts E, E, it may be brought into
such position by a sliding motion as shewn at Figs. 6b, 6º, 6d, (Sheet V.) which
shew views corresponding respectively with those at Figs. 5, 5ª, 6 and Ga. In this
arrangement the commutator disc A is arranged to slide laterally for bringing its
plates from the position shewn at Fig. 6c into the opposite position relatively to the
contacts E. For this purpose the socket C carrying the commutator with its
spindle a, button a², and spring are fixed to a sliding plate G sliding between
guides G on the door of the instrument, upon which are marked in opposite
positions the words "line clear" and "train on line," so that when the commu-
tator is slid into position for making electrical connections with the contacts E
corresponding to "line clear," the slide G will uncover the words "line clear" and
will cover the words "train on line," and vice versa. The door has a slot for
allowing of the sliding motion of the sleeve and spindle of the commutator within
it, the ends of the slot serving as the stops determining the exact extent of such
motion. In this case the contact springs E are arranged as indicated in dotted
lines, so that when the commutator is in the position shewn at Fig. 6c the contacts
to "line wire" and to "battery +," and those to "lower instrument coils" and to
"battery are respectively connected by the plates 1 and 2, while when in the
opposite position the plate 3 connects "line wire" with "battery -," and plate +
connects "lower instrument coils" with battery +. The contact F to upper instru-
ment coils in this case also forms the stop such as was described in the previous
arrangement for preventing the commutator A from being moved forward against
the contacts until it has been slid laterally into proper position, and also for
"

page_text: preventing it from being shifted laterally while contact is being made. The
commutator is for the purpose notched out at f, f, as shewn.
It is obvious that in the above described arrangements of commutators having both
a rotary or sliding motion and a forward motion for making the proper contacts,
the arrangement of contact plates and springs might be reversed, that is to say,
the contact springs might be carried by the rotating or sliding disc or plate while
the contact plates are fixed at the back of the instrument case.
Fig. 7 is a front view of another signalling instrument suited for indicating succes-
sive numbers of trains admitted on a section of a railway line such as a goods yard;
Fig. 7 represents the hinged door of the casing folded back to shew the mechanism
within; Fig. 7b and 7° shew detached parts of the mechanism; and Fig. 8 is a vertical
section. In this case a disc G marked with successive numbers is fixed on the sleeve
B so that at every partial turn of that sleeve effected by the hand applied to the
button D, a fresh number up to 6 (or to a greater number if the circumstances of
the case require it) is presented through the glass H. The sleeve also carries a
wheel K having pins, teeth, or cogs which engage with slopes on a spring lever L,
as is more clearly shewn at Fig. 7°, so that the commutator is in all cases caused to
turn to a complete division. A locking plate M has on its circumference notches
with which engages a spring lever N that prevents the commutator from being
turned in either direction except when the operator by pressing a button O at the
side of the instrument pushes in the tail of the lever N, raising the catch at
its end out of the notch of the wheel M, and permitting it to be turned one division.
Another lever P has a tail projecting downwards and forming a stop to a pin p on
the face of the locking plate M, so that after the commutator has been turned
through all its divisions in one direction, the successive numbers shewing at the
glass H, the operator can turn it back, division by division, shewing the numbers
in reverse order as the trains that had been admitted to the section successively
leave it. Instead of the disc G being marked with successive numbers, it may be
made to indicate the description of train as shewn at Fig. 7d (Sheet IV.). Fig. 9
is a front view of a modified form of the instrument above described; Fig. 9a
shews the hinged door folded back; Fig. 9b shews a similar view to 9a with the
indicating parts and commutator turned to the opposite position for transmitting
"line open;" and Fig. 10 is a side view with part of the casing removed to shew
the interior. In this case the commutator and its sleeve can only be turned a
certain distance forwards and backwards by the nob D so as to shew at the glass H
either "line open" or "line closed." But on the sleeve is fixed a crank arm P, on
which is mounted a disc Q having successive numbers as from 1 to 6 marked on
it so as to present themselves through a hole in the screen G. The disc has on
its back pins, which at each back stroke of the screen G, when it shews "line clear"
at the glass H, come in contact successively with a pawl R, causing the disc Q to
turn one of its divisions round so that when the screen G makes its forward stroke:
shewing at H "line closed," there is presented also through the hole in the screen
the number of the division to which the disc Q had been turned, indicating the
number of trains admitted to the section. By means of a spring pusher S at the
side of the instrument the attendant can by successive movements thereof turn
backwards the disc Q as each of the admitted trains successively leaves the section
of line; Fig. 11 is a front view of a block signal instrument adapted for being con-
nected by interlocking with the main signals of the station; Fig. 11 shews the
hinged door folded back, and Fig. 12 is a side view with part of the casing removed
to shew the interior. In this instrument, beside the ordinary screen G presenting
at the glass H either of the indications "line clear" or "train on line," there is a
second screen T loaded by a weight t, and held back by a pawl U; under this pawl
is the tail of a spring lever V, which is connected by a wire with the main signal,
so that when the signal is raised to the "danger" attitude the pawl U is also raised,
allowing the screen T to advance in obedience to the weight t, and present itself at
the glass H with the indication "line closed" in front of and intercepting the

page_text: screen G. Under the weight t is mounted a pawl lever W, which engages with a
pin on the commutator sleeve, preventing the sleeve from being turned backwards
to shew "line clear "except when the weight t bearing on the tail of the lever W
depresses that tail, and raises the front catch of the lever clear above the pin w.
The mode of operating with this instrument is as follows:-Assuming the com-
mutator to be in position for signalling "line clear," that indication on the screen
presenting itself at the glass H when a train comes on the section the operator
moves the commutator to signal "train on line," the screw shewing that indication
at H; he cannot now turn back the commutator to "line clear" because the pin w
is engaged with the catch of the lever W. If in obedience to the message sent
"train on line" he or another signalman raises the main signal to "danger," this
act by moving the lever V raises the pawl U, whereupon the screen T advances,
shewing at H the indication "line closed." But by this movement the weight t
acting on the lever W releases the pin w, and the line being protected by the main
signal standing at "danger" the attendant can now turn back the commutator and
screens to the position for "line clear." Fig. 13 shews the arrangement with the
above described screen T marked with "line closed," adapted to the construction of
instrument with sliding commutator described with reference to Figs. 6b, 60, 6d. In
this case the words "train on line." are marked on a plate a sufficient distance behind
an opening in the instrument door to allow the screen T bearing the words "line
closed" to pass down in front of it. This screen is pivotted to the door at T¹, and
has a tail T so formed that when the commutator is slid so that the screen G
uncovers "line clear" its spindle a in pressing against the tail raises the screen T
into the position shewn in dotted lines, where it is held by the spring catch V¹,
so that on again sliding back the commutator and screen G over "line clear," the
words "train on line" appear. On the main signal being raised to ". danger" as
before described the pull on the lever V releases the screen from its catch, and the
screen in falling into the dotted position T3 shews "line closed."
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim,―
First. The construction of cylindrical armature herein described with reference
to Figs. 1 and 2 of the accompanying Drawings.
Second. The construction of double anchor balanced armature herein described
with reference to Figs. 3 and 4.
Third. In block signalling telegraphic instruments, so arranging the commutator
that it is kept away from the electrical contacts while it is being moved into
position for bringing its conducting plates opposite the proper contacts for estab-
lishing the desired electrical connections, and can then be brought against such
contacts, means being provided for maintaining the commutator in its proper
position while such contact is being made, substantially as and for the purposes
herein described.
Fourth. The use in combination with the arrangement of commutator referred
to in the preceding claim of a screen actuated by the cominutator spindle, and also
put in connection with the main signal so as to unlock the commutator and shew
"line closed" when the main signal is raised to "danger," substantially as herein
described.
Fifth. In block signalling telegraphic instruments arranging the commutator
stem to slide without turning within a sleeve that can be turned only when the
commutator is clear away from the electrical contacts, substantially as and for the
purposes herein set forth.
Sixth. The construction of block signalling instrument as herein described with
reference to Figs. 5, 5ª, 5b, 6, and 6a.
Seventh. The construction of block signalling instrument indicating the arrival
of successive trains, as herein described with reference to Figs. 7, 78, 7b, 70, 7ª,
and 8.
Eighth. The modified construction of block signalling instrument indicating the
'

page_text: arrival of successive trains, as herein described with reference to Figs. 9, 9a, 9b,
and 10.
Ninth. The construction of block signalling instrument adapted for interlocking
with the main signal, as herein described with reference to Figs. 11, 11 and 12.
In witness whereof, I, the said Edward Tyer, have hereunto set my hand
and seal, this Eleventh day of September, in the year of our Lord One
thousand eight hundred and seventy nine.