Improvements in Apparatus for Ensuring Safety on Single Lines of Railway.
Year: 1892

page_text: Date of Application, 12th Feb., 1892
Complete Specification Left, 14th Nov., 1892-Accepted, 17th Dec., 1892
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,
Electrical Engineer, lo hereby declare the nature of this invention to be as
follows:-
In previous Specifications, particularly No. 5928 of 1890, I have described
apparatus for ensuring safety on single lines of railway by electrically controlling
the issue from a station of a tablet to be carried by a train to a station beyond, this
tablet being a convenient substitute for the staff which a train usually carries with
it from one station to the next, so as to provide against more than one train being
on the section between those stations at one time. A set of the apparatus described
in these Specifications being established at each of two stations, and being suitably
connected electrically, no tablet can be issued from the apparatus at the one station
unless it is electrically released by the operator at the other station, and he does
not effect this release unless he knows that the section is clear, and he cannot effect
this release if he himself has already issued a tablet for a train proceeding to the
other station, unless that tablet shall have been received there.
The object of my present invention is to render apparatus of the kind referred to
more simple in construction and efficient in action.
In the apparatus described in the Specifications above referred to a slide moved
by hand is employed for moving a tablet out of or into the receptacle provided, but
the movement of this slide is governed by pawls which can only be released by the
operation of electromagnets having their coils suitably connected to a relay
operated by electrical currents transmitted by the line wire connecting the stations.
One object of my present invention is to effect the movements of these pawls by
the hand of the operator, employing the electromagnets merely to withdraw
catches so as to leave the pawls free to be moved. I can thus employ pawls of
greater weight and of more certain action than when they themselves have to be
moved electrically. The catches above referred to can only be released by the
joint operation of the two signalmen at the two separate stations, and thus all
danger of a tablet being improperly issued is avoided.
The apparatus, is, like those described in my former Specifications, provided
with a commutator and signalling plunger so arranged that the signalmen at
the two stations, whom I may indicate as A and B, can operate in the following
manner.
Assuming that A desires to issue a tablet for a train proceeding towards B,
A by depressing several times his signalling plunger gives B the preconcerted
signal.
B by moving his plunger can answer, and then, if his electrical connections as
well as A's are in suitable condition, he can transmit a current whereby a catch
in A's apparatus is withdrawn, enabling A. by turning his commutator to release a
pawl, and then to draw out his slide and issue a tablet. By this act of releasing
one pawl, A causes the engagement of another pawl which prevents his slide
from being pushed in again, until B, having received the tablet, shall have put
it into his apparatus, thereby so acting on his own commutator that he can send
to A a current of the opposite sign to that which released A's slide for drawing
it out, thus causing withdrawal of a catch enabling A to release the second pawl
and push in his slide.
All the connections are thus brought into condition for operating again in like
manner

page_text: Sometimes tablets are issued for shunting purposes, and thus A may receive back
the tablet which he has issued without its passing to B. Although A having
drawn out his slide to issue this tablet cannot push his slide in again while it is
empty, he can by re-inserting the tablet canse release of the pawl enabling him to
push in the slide with the tablet in it, and to restore his commutator to condition for
operating afresh.
The lever described in my former Specification for raising tablets out of the
recess of the slide, becomes bolted when the operator moves his commutator for
the purpose of taking out a tablet. The sliding bar, employed in my former
apparatus to be pushed by the edge of a tablet when the slide is pushed in and
thereby to act on the electrical connection, has its front end, according to my
present invention, jointed and counterpoised by a weight or spring so as to yield to
the weight of superposed tablets above it, but to present its end directly to the edge
of an entering tablet so as to be pushed by it.
Dated this 12th day of February 1892.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Ensuring Safety on Single Lines
of Railway.
I, EDWARD TYER, of Ashwin Street, Dalston, in the County of London,
Electrical 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 previous Specifications, particularly No. 5928 of 1890, I have described
apparatus for ensuring safety on single lines of railway by electrically controlling
the issue from a station of a tablet to be carried by a train to a station beyond,
this tablet being a convenient substitute for the staff which a train usually carries
with it from one station to the next, so as to provide against more than one train
being on the section between those stations at one time.
A set of the apparatus described in these Specifications being established at each
of two stations, and being suitably connected electrically, no tablet can be issued from
the apparatus at the one station unless it is electrically released by the operator at
the other station, and he does not effect this release unless he knows that the
section is clear, and he cannot effect this release if he himself has already issued a
tablet for a train proceeding to the other station, unless that tablet shall have been
received there.
The object of my present invention is to render apparatus of the kind referred
to more simple in construction and efficient in action.
In the apparatus described in the Specifications above referred to a slide moved
by hand is employed for moving a tablet out of or into the receptacle provided, but
the movement of this slide is governed by pawls which can only be released by the
operation of electromagnets having their coils suitably connected to a relay operated
by electrical currents transmitted by the line wire connecting the stations. One
object of my present invention is to effect the movements of these pawls by the
hand of the operator, employing the electromagnets merely to withdraw catches so
as to leave the pawls free to be moved. I can thus employ pawls of greater weight
and of more certain action than when they themselves have to be moved electrically.
The catches above referred to can only be released by the joint operation of the
two signalmen at the two separate stations, and thus all danger of a tablet being
improperly issued is avoided.
The apparatus, is, like those described in my former Specifications, provided
with a commutator and signalling plunger so arranged that the signalmen at the
two stations, whom I may indicate as A and B, can operate in the following
manner.
.:

page_text: Assuming that A desires to issue a tablet for a train proceeding towards B,
A by depressing several times his signalling plunger gives B the preconcerted
signal.
B by moving his plunger can answer, and then, if his electrical connections as
well as A's are in suitable condition, he can transmit a current whereby a catch
in A's apparatus is withdrawn, enabling A by turning his commutator to release
a pawl, and then to draw out his slide and issue a tablet. By this act of
releasing one pawl, A causes the engagement of another pawl which prevents his
slide from being pushed in again, until B, having received the tablet, shall have
put it into his apparatus, thereby so acting on his own commutator that he can
send to A a current of the opposite sign to that which released A's slide for drawing
it out, thus causing withdrawal of a catch enabling A to release the second pawl
and push in his slide.
All the connections are thus brought into condition for operating again in like
manner.
Sometimes tablets are issued for shunting purposes, and thus A may receive
back the tablet which he has issued without its passing to B. Although A having
drawn out his slide to issue this tablet cannot push his slide in again while it is
empty, he can by re-inserting the tablet cause release of the pawl enabling him to
push in the slide with the tablet in it, and to restore his commutator to condition
for operating afresh.
The lever described in my former Specification for raising tablets out of the
recess of the slide, becomes bolted when the operator moves his commutator for the
purpose of taking out a tablet. The sliding bar employed in my former apparatus
to be pushed by the edge of a tablet when the slide is pushed in and thereby to act
on the electrical connection, has its front end, according to my present invention,
jointed and counterpoised by a weight or spring so as to yield to the weight of
superposed tablets above it, but to present its end directly to the edge of an
entering tablet so as to be pushed by it.
As apparatus according to my present invention is, except in respect of certain
modifications, substantially the same as that described in my former Specification
No. 5928 of 1890, I now repeat, except Fig. 6, the figures of the drawings annexed
to the said Specification, employing as far as possible, the same letters of reference,
so that the parts of the mechanism corresponding with those formerly shewn may
be readily identified. Thus, referring to the accompanying drawings,
Fig. 1 is a perspective view of one complete set of the apparatus consisting of the
tablet receiving and issuing mechanism A, the bell signalling apparatus B, and the
electrical communicating apparatus C.
Fig. 2 is a side elevation and Fig. 3 is a plan of the tablet receiving and issuing
gear within the casing A.
Figs. 4 and 5 are part longitudinal sections of the same.
Fig. 7 is a view looking from behind of parts of the electrical communicating
apparatus immediately behind the front cover of C Fig. 1.
Fig. 8 is a view looking from the front of the parts behind those shewn in Fig. 7.
Fig. 9 is a diagram shewing the electrical connections.
The cylinder D containing the tablets D', and the slide D2 by which a tablet
can be taken out or put in, are arranged as before, as also the hand lever D' for
raising the tablets in the cylinder, but this lever is, according to my present
invention prevented from rising to its full height sufficient to raise the tablets out
of the slide by the nose d coming against a piece d' fixed on a rod which is
moved by a bell crank d acted on by a rod dwhich is linked to one of two arms
on the axis T of the commutator. The slide D' is, as before stopped by a pawl E
which prevents it from being drawn out, there is also a pawl e which prevents the
slide D from being pushed quite in. This pawl is released by the descent of a
rod e¹ which is linked to the other of the two arms on the axis T of the commu-
tator.

page_text: The rods d and e¹ have on their lower parts shoulders over which project the
armatures do and e² respectively.
The axis of the commutator cannot be turned in either direction unless one or
other of these armatures is attracted.
When is attracted the commutator can be turned back to the right.
By turning the commutator to the left the rod d' is lowered depressing one
arm of the bell crank d³ and thereby causing a projection d to act on the tail of
the pawl E raising it out of the notch of the slide D³ and so permitting the slide to
be drawn out with a tablet.
By turning the commutator to the right the pawl E becomes again free to
engage in the notch of the slide, and the rod e¹ is lowered depressing one end of the
pawl levere so that the pawl cannot engage in the notch of the slide D². On the
axis T of the commutator which can be turned by the knob T', when the armatures d³
and permit, is fitted a disc T' free to revolve a certain distance as determined by
a slot in it engaged by a pin on the arm to which do is linked. Also rigidly con-
nected to this disc is another disc T' of insulating material with two metal
semicircles on its face insulated from one another. These metal semicircles, when
the signalling plunger T is pushed in make electrical contact with the four
springs t¹t connecting them in pairs in circuit according as the commutator
axis T is turned to right or left. A rod t carries at its lower end a roller to which
rests on an incline on the sliding bar G.
When the slide D' is pushed in with a tablet the sliding bar G is pushed back
causing the roller to and rod t to rise. By the rising of the rod t acting on a pin t'
on the disc T this disc is turned partly round turning with it the commutating
disc T and thereby altering the circuits, should the plunger T be pushed in. But,
when the armature e is attracted, an arm e extending up from it bears against a
pawle which held the disc T', releasing this pawl and allowing the disc T' to be
moved back by the weight e'.
Z is a bell crank the upright arm of which is hooked so as to engage on a
pin and thereby prevent the rod e¹ from being raised should the slide D³ not
have been pushed in. But when it is pushed in a projection on the slide
raises the lower arm of the crank Z thus moving its hooked arm clear of the
pin z.
From what precedes it will be seen that the attraction of the armatures d
and has not to perform the work of releasing the pawls which hold the slide D'
as in the apparatus described in my previous Specification, all that these armatures
have now to do is to permit the signalman to turn the commutator axis T, which
turning effects two purposes, first, it releases the pawl which is holding the slide D'
and secondly it puts the disc T' in such a position that, when the plunger T' is
pushed in, it makes the right contacts of the springs t¹ t² tª tª.
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 apparatus of the kind described in the Specification No. 5928 of 1890,
operating the pawls which hold the slide by rods which are linked to arms on
the commutator axis, and which are stopped by armatures of electro magnets
except when these armatures are attracted, substantially as and for the purpose
herein set forth.
2. The combination of the signalling plunger and commutating disc attached to
it, the axis that can be turned by hand, and the arms, rods linked thereto and
armatures which stop the rods unless they are attracted, substantially as described.
Dated thie 14th day of November 1899
ABEL & IMRAY,
Agents for the Applicant.