Improvements in Apparatus for Ensuring Safety on Single Lines of Railway.
Year: 1895

page_text: Date of Application, 16th Nov., 1895
Complete Specification Left, ist Aug., 1896-Accepted, 19th Sept., 1896
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Ensuring Safety on Single Lines of
Railway.
I, EDWARD TYER, of Ashwin Street, Dalston, in the County of London,
Engineer, do hereby declare the nature of this invention to be as follows :-
In my previous Specifications No. 1262 of 1878, No. 42 of 1888, No. 5928
of 1890, No. 1904 of 1891, No. 18603 of 1891, No. 2798 of 1892 and No. 12144
of 1893, I have described apparatus for ensuring safety of traffic on single lines of
railway by clectrically controlling the issue from a station of a tablet or staff to
be carried by a train to a station beyond, thus providing against the admission of
trains travelling in opposite directions into any section of the line.
My present invention bas for its object to simplify the construction and
operation of apparatus of this kind.
For this purpose, I provide at each of the two stations terminating a section,
an apparatus for the reception and issue of tablets, operated in the following
manner.
Denoting the two stations as A and B, assuming that the section is clear and
that the electrical connections are such that A and B can communicate by the
line wire-when A requires to issue a tablet to a train he proceeds as follows:
A first signals by bell to B by depressing a ringing plunger a pre-arranged
number of times; B replies to this signal, and, by holding down his own ringing
plunger causes a current to pass along the line wire to A, and through the coils
of a polarized electro-magnet. The armature of this magnet, being thus moved,
puts a local battery at A in circuit with a second electro-inagnet at A. The
armature of the latter electro-magnet being attracted raises a pawl which is
engaged in a slot of a slide guided to travel under receptacle containing
a number of tablets and having a recess in which the lowest of these tablets is
held. This slide being unlocked by the raising of the pawl, A can draw it out
with the tablet in its recess, and can give the tablet to the departing train..
The slide, when thus drawn out turns a revolving commutator partly round
and this reverses the polar connections of the instrument at A with the ringing
plunger and also with the contacts of the relay and renders the operator at A
incapable of transmitting to B any currents that would permit the withdrawal of
a second tablet at B, and also preventing transmission of currents from B to A.
When the operator at A inserts a tablet into bis apparatus, the tablet as it passes
to the receptacle again actuates the commutator and this by again reversing
the polar connections places A again in communication with B. Thus the with-
drawal or the insertion of a tablet, causes the commutator to reverse alteruately
the polar connections to the ringing plunger and polarized relay.
When the apparatus at A and B are at first in communication with each other,
both have their ringing plungers in connection with, say the + terminal of the
battery. When either A or B withdraws a tablet from his receptacle the distant
apparatus remains in connection with the + terminal, but the apparatus from
which the tablet is withdrawn is then automatically connected to the terminal,
the polarized relay being then brought into such a position as to prevent a
second tablet from being withdrawn. When a tablet is then inserted at the
distant end of the section, both apparatus are again put in communication, the

page_text: polar connections of the ringing plungers being now to the terminal. Also when
a tablet is inserted into the instrument from which it had been taken, the com-
munication of A and B is again re-established as at first, their ringing plungers
and polarized relays being again both connected to the + terminal.
Although I have described apparatus adapted for use with a tablet, it may
readily be modified so as to suit it for use with a staff, the operation being the
same as is above set forth.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Apparatus for Ensuring Safety on Single Lines of
Railway.
EDWARD TYER of Ashwin Street Dalston in the County of London Engineer
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 :-
In my previous Specifications No. 1262 of 1878, No. 42 of 1888, No. 5928
of 1890, No. 1904 of 1891, No. 18603 of 1891, No. 2798 of 1892 and No. 12144
of 1893, I have described apparatus for ensuring safety of traffic on single lines of
railway by electrically controlling the issue from a station of a tablet or staff to be
carried by a train to a station beyond thus providing against the admission of
trains travelling in opposite directions into any section of the line.
My present invention has for its object to simplify the construction and operation
of apparatus of this kind.
For this purpose 1 provide at each of the two stations terminating a section,
an apparatus for the reception and issue of tablets operated in the following
manner.
Denoting the two stations as A and B, assuming that the section is clear and
that the electrical connections are such that A and B can communicate by the
line wire, when A requires to issue a tablet to a train he proceeds as follows:-
A first signals by bell to B by depressing a ringing plunger a prearranged
, number of times; B replies to this signal, and, by holding down his own ringing
plunger causes a current to pass along the line wire to A, and through the coils of
a polarized electro-magnet. The armature of this magnet, being thus moved puts
a local battery at A in circuit with a second electro-magnet at A. The armature
of the latter electro-maguet being attracted raises a pawl which is engaged in the
slot of a slide guided to travel under a receptacle containing a number of tablets
and having a recess in which the lowest of these tablets is held. This slide being
unlocked by the raising of the pawl A can draw it out with the tablet in its recess
and can give the tablet to the departing train.
The slide, when thus drawn out turns a revolving commutator partly round and
this reverses the polar connections of the instrument at A with the ringer plunger
and also with the contacts of the relay and renders the operator at A incapable of
transmitting to B any currents that would permit the withdrawal of a second
tablet at B, and also preventing transmission of currents from B to A. When the
. operator at A inserts a tablet into his apparatus, the tablet as it passes to the
receptacle again actuates the commutator and this by again reversing the polar
connections places A again in communication with B. Thus the withdrawal or the
insertion of a tablet causes the commutator to reverse alternately the polar con-
nections to the ringing plunger and polarized relay. When the apparatus at A
and B are at first in communication with each other, both have their ringing

page_text: -
plungers in connection with, say the + terminal of the battery. When either A
or B withdraws a tablet from his receptacle the distant apparatus remains in
connection with the + terminal but the apparatus from which the tablet is with-
drawn is then automatically connected to the – terminal, the polarized relay being
then brought into such a position as to prevent a second tablet from being with-
drawn. When a tablet is then inserted at the distant end of the section, both
apparatus are again put in communication, the polar connections of the ringing
plungers being now to the terminal. Also when a tablet is inserted into the
instrument from which it had been taken the communication of A and B is again
reestablished as at first, their ringing plungers and polarized relays being again
both connected to the + terminal.
Although I have described apparatus adapted for use with a tablet, it may
readily be modified so as to suit it for use with a staff, the operation being the
same as above set forth.
For operating as above described with tablets, the apparatus at each of the
stations is constructed as I shall now explain referring to the accompanying
drawings.
Figure 1 is a longitudinal section, Figure 2 is a side elevation partly in section,
Figure 3 is a transverse section on X X Figure 1, Figure 4 is a plan on Y Y
Figure 1.
A is the casing on the apparatus having on the top a pair of signalling
plungers a and a semicylindrical casing B containing a pivotted semicylinder
which can be turned partly round by an external handle b. When bis in
the position shewn in Figure 1, a tablet can be introduced into its slot as far as
permitted by a stop and then it can be turned partly round bringing its slot in
line with the inclined way 63 down which the tablet slides to the receptable C in
which a number of the tablets can be accommodated. The tablet in sliding down
the incline 3 moves aside a counterweighted lever D, carrying a pawl & which
on the return stroke of D, effected by the counterweight, turns a ratchet wheel d
one tooth round thereby turning partly round a commutating wheel against
which bears the finger d of a loaded bell crank lever. This lever carries
insulated springs d which when the parts are in, the position shewn in Figure 1
bear against upper contacts d' and when they are as shewn in Figure 2 bear
against lower contacts d³.
Under the receptacle C is arranged the horizontally sliding plate E, having a
recess e of such depth as to receive one tablet T and no more. The slide E when
pushed in as in Figure 1 is held by a hook pawl e' attached to the armature of an
electro-magnete, so that the slide E cannot be drawn out. But when a current of
electricity excites the magnet e, as determined by the action of the signalman at
the other station, its armature is attracted raising the hook e₁ and leaving the
slide E free to be drawn out along with a tablet in its recess e. The operator can
take out the tablet and hang it on a pint ready to be delivered to a train going
from the station. On the slide E is fixed a bracket F having two laterally pro-
jecting pins ff¹ between which is situated an arm of a lever G carrying a pawl g
which acts on a ratchet wheel g¹ on the same axis with the ratchet wheel d¹ and
with the commutating wheel d². When the slide E is pulled out to withdraw a
tablet the pin fmoves the lever G so that its pawl turns the commutating wheel
partly round altering the contacts at d³ and d. When the slide E is pushed in to
be again held by the hook e¹ the pin pushes back the lever G causing its pawl
to take a position ready to act on another tooth of the ratchet wheel d¹. Thus
when a tablet is put in at B and slides down to C the commutating wheel d², as
already explained is turned so as to alter the contacts d and d³ and also when the
slide E is drawn out to take out a tablet, the commutating wheel is turned so as to
alter these contacts. Thus the introduction of a tablet or the removal of a tablet
alters through the contacts d and d the current communicating with the next
station from + to - and then from
to and so on alternately. Under the
slide E is pivotted a counter-weighted lever H the front end h of which, if the
-

page_text: slide were partly pushed in with a tablet in its recess e, would catch the edge of
the tablet and so prevent the slide from being pushed farther in. Thus the slide
cannot be pushed home with a tablet in its recess. When the slide E without a
tablet is pushed home, it makes contact by a bridge piece with two spring pins at K
thus establishing electrical communication by the line; but when the slide is drawn
out or pushed only partially in, there is no contact at K and consequently there
can be no communication by the line wire. A tappet L projecting down from the
slide E meets at each end of the stroke stops 14 which determine the stroke of the
'slide and are preferably faced with wood or other deadening material.
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:-
Apparatus for ensuring safety on single lines of railway constructed and operating
substantially as described with reference to the accompanying drawings.
Dated this 1st day of Amint 1906.
1
ABEL & IMRAY,
Agents for the Applicant.