Improvements in Apparatus for Ensuring Safety of Traffic on Single Lines of Railway.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Ensuring Safety of Traffic on Single
Lines of Railway.
I, EDWARD TYER of Ashwin Street, Dalston in the County of Middlesex, 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 working the traffic on single lines of railway, each train is usually required to
carry with it some article, such as a baton or staff, receiving it at one station and
depositing it at the next, as a security against the possibility of two trains meeting on
one section of the line.
In the Specification of Patents granted to me in England and elsewhere I
have described the use of a disc or tablet instead of a staff, and apparatus electrically
connected from station to station in such a manner that the operator at one station
cannot issue a tablet permitting a train to proceed along a section of the line until
the apparatus which controls the issue of the tablet at his station is electrically released
by the operator at the next station down, who should effect this release only when he
knows that the section is clear by having received the tablet from the last train
passing down, and who cannot effect the release when he himself has issued a tablet
for a train passing up, until that tablet has been received at the next up station. At
each station the apparatus is in duplicate, the one in communication with the next
station up and the other with the next station down so that the traffic is controlled in
both directions. My present invention relates to improved apparatus for reception
and issue of the tablets and for effecting the electrical communications from station
to station, as I shall describe 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. 6 is a front view of the bell apparatus.
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.
Within the casing A under its fixed cover is placed a cylinder D capable of
containing a number of tablets D' which are discs of metal. The cylinder D is
covered at the top and under its bottom there is a horizontal slide D2 which can
be drawn out or pushed in by hand. In this slide there is a recess D³ deep
enough to accommodate one of the tablets D'. When the slide is pushed in so
that the recess D³ is immediately under the cylinder P, the lowest of the tablets D'
can be received in the recess, and then on drawing out the slide until the tablet
presents itself outside the front of the casing A, the tablet can be removed from
the recess.
Conversely, the slide being drawn out, a tablet can be put into its recess, and then,
on the slide being pushed in, this tablet can be raised by means presently to be
described into the cylinder D. Thus there are no means of taking a tablet from
the cylinder or putting a tablet into it except by operating the slide D. Under the
slide there is pivotted to the framing an arm D which by means of a hand lever D,
presented outside the casing A at one side thereof, can be raised so as to bring its

page_text: raised end D up to the level of the bottom of the cylinder D. By this action a tablet
lodged in the recess D³ of the slide can be pushed up into the cylinder, and as the
slide D2 has along its middle a longitudinal slot a little wider than D, the slide can
be pulled out its full stroke while D is raised and consequently while the recess D³
contains no tablet
At the side of the slot of D² there is a notch into which a projection D' from D'
can rise when the slide is in its back position. When the slide is in any other
position presenting no notch to receive D' then the arm D cannot be raised by the
handle D. In the face of the slide D² there is a notch D8 to receive a catch pawl E².
When that catch is engaged in the notch D³, as shewn in Fig. 2, the slide D² cannot
be pulled out, and it is not until the catch E2 is raised out of the notch that the slide
can be drawn out. The catch E² can be raised by either of two operations. It can
be raised as shewn in Fig. 5 by raising the arm D by means of the hand lever D³.
When it is thus raised the projection D' being above the upper face of the slide D²
the slide can be pulled out but without a tablet in its recess D³ the arm D being held
up by its projection D' sliding above the upper face of the slide D². Or, without
raising the arm D when an electromagnet E, excited by a current of electricity,
attracts its armature E¹ and this acting on the hinder hook of E2 raises its front
hook out of the recess D³. In this case the slide D2 can be pulled out with a tablet
in its recess D³. For the proper action of the electrical contacts, as will presently be
explained, it is necessary that the slide D² when it is pushed in should be pushed
fully home, but in case it might happen to be pushed not quite home an additional
notch D is provided to receive the catch E2 and so to prevent the slide from being
drawn out again until the electrical connections are established by pushing it quite
home allowing the catch E2 to be engaged in the front notch D³. On the slide D² is
a raised part consisting of a plate D¹º fixed on it and having a sloped end D. This plato
performs three functions. First, as the slide D2 is drawn out taking with it a tablet,
the plate D coming against a sliding plate D12 pushes forward a sliding bolt D¹³
attached to D12 underneath thus moving certain of the electrical parts connected
to D12. If the slide D' be pushed in without having a disc in its recess, D12 and D¹³
are left in the position to which I had moved them. But if the slide be pushed in
with a disc in its recess, the disc meeting the bolt D¹³ pushes it and D12 back to the
position which they occupied before 110 moved them. The second function of D10 is
that, as the slide D2 is drawn out, the sloping edge Du comes under a roller F¹ and
thus raises one end of a lever F, the other end 12 of which normally makes an
electrical contact, which contact is broken when the roller F¹ is raised by D" and is
kept broken while the plate Do continues to pass or remain under the roller F.
The third function of 110 is that two sloping parts on its face act on a tail piece D¹4
projecting down from a lever D15, the end of which is made with a shoulder. When
the tail piece D is down on the face of the slide and the slide is pulled out, the
shoulder of D dropping in front of a fixed edge prevents the bolt D13 from being
pushed back as it might be by inserting a rod at the open recess of the slide. But,
when the slide is pushed in with a tablet in the recess, the tail piece D14 is raised by
an incline on the plate D10, and then on the slide D2 being pushed back the disc in
its recess meets the bolt D₁s and pushes it back thus moving back the plate D¹² and
the parts connected to it which are as follows. An arm G pivotted on D¹² extends
backwards and is kept steady against accidental shifting by fixed springs G¹ which
bear against its sides with a pin entering the one or the other of two countersunk
holes on the sides of G, thus holding it steadily in its front or rear position. On G is
pivotted the lever D₁ above referred to, and near the hinder end of G a bracket G2
projects upwards having a pin G³ projecting at one side. Also on the other side
of G2 is pivotted a lever having a projecting pin G. By the to and fro movements
of G with G, the pins G³ and G operate electrical connections in the following
manner. His a cylindrical commutator having on its perephery metal plates arranged
to make electrical connection of some of 6 springs H to H which bear upon it. In
one, which may be termed the front position of the commutator, the two springs H*
and H are connected, and H³ and H are connected, but when the commutator is

page_text: turned partly round to its back position H' is connected to H2, H3 to H* and H
to H. It is turned to this latter position (as indicated by dotted lines in Fig. 4) by
the pin G³, when the slide containing a tablet is pushed back, acting on an arm H
projecting from the axis of H. It can also, under certain circumstances, be turned
to this back position by the armature K' of an electro magnet K. The armature is
turned forward to the front position first mentioned (as shown in full lines in Fig. 4)
by a lever H having projecting down from it a hook arm H' which on drawing out
the slide D is engaged by the hook of a counterpoised pawl lever H10 pivotted at H"
on the slide D2. Thus when the slide is drawn out the commutator H is in its
front position, and if the slide be pushed in without a tablet in its recess D³ the
commutator remains in that position, because in that case the lever G with pin G³ is
not moved back, and it is only when the slide is moved back with a tablet in its
recess that the commutator H is turned to its back position. The pin G* when G² is
pushed back passes under a cam shaped projection L2 on the side of a lever L' and
thus raises the lever L' and a rod I extending up from it to part of the electrical
apparatus in C. After the pin G4 has passed the projection L2 the lever L¹ and
rod L descend and then the pin G in its movement towards the front rides over the
projection L² without doing anything and drops in front of it ready to operate
again.
In the bell apparatus B shewn in Fig. 6, the electro-magnet M when excited in
the usual way by a rapid succession of currents causes its armature M' to vibrate and
sound the bell. At the same time a rod M2 linked to the armature acts upon two
contact springs M³ and M₁ causing them also to vibrate. By loading the one
spring M more than M³ its period of vibration is made to differ from that of M³
and consequently during rapid vibration of the springs each of the contacts made by
them is of so short duration that no current is transmitted by them sufficient to
excite an electro magnet to the coil of which the spring M* is connected. But if, by
maintaining for some time a continuous current to act on the bell magnet M causing
it to hold its armature M' attracted, the two springs M3 M4 are held in contact, thero
is time for the current transmitted by them to excite such magnet as may be
connected to M*.
Referring now to the electrical apparatus in C as shewn partly in Fig. 2 and in
Figs. 7 and 8 and the diagram Fig. 9 there are two spring plungers marked
in Fig. 1 respectively "Tablet in" and "Bell." By pushing in the "Tablet in"
plunger against springs t¹, 2, 3, and tb, t', is electrically connected to t² and t³ to tb
but tb is itself pushed back breaking contact with a stud N. Again by pushing in
the "Bell" plunger 6' is connected to 62 and 63 to t. b. but t. b. is disconnected from N.
The "Bell "plunger is always free to be pushed in, and it serves for bell signalling
to the next station. The "Tablet in" plunger which is shewn at T in Fig. 2 has
projecting down from it an arm T¹ immediately in front of the upper end T² of a
lever the lower end T3 of which is in front of the spring armature T³ of an electro
magnet To which armature is shewn in Fig. 2 as being attracted.
In this position of the parts the plunger T cannot be pushed in being stopped
by T
But when the rod L is raised as previously described it meets a pro-
jection T from the lever and for a moment raises the end T³. If at this moment the
armature T is not attracted, it is moved by its spring under T³ and holds the lever
in the position to which it was moved by the rod L in which position T2 is out of
the way of T¹ and consequently the plunger T can be pushed in. When however
the magnet T is excited, it attracts its armature To allowing T³ to drop and thereby
bringing T² to the position to prevent the plunger T from being pushed in.
PP Fig. 8. is the electro magnet of a polarised relay the tongue P¹ of which is
magnetised by induction from permanent magnets fixed at the back of the casing
indicated by the dotted lines P (Fig. 8). The tongue F' according as the magnet P
is excited by a current of the one or the other direction, makes either the
contacts P³ and P³ or the contacts P' and P. Another electro magnet I according
to the direction of the current in its coils deflects to the one side or the other a

page_text: "
tongue which is magnetised by induction from a permanent magnet I² fixed
within the front of the casing. The tongue I¹ has on its axis the index which
appears in the upper part of the front of the casing C. Another electro magnet S in
like manner works a tongue Scarrying a screen which presents itself through an
opening in the front of the casing C shewing that a tablet say for the up train is
in or out." Farther a screen S³ which also presents itself through an opening
shewing whether a tablet say for the down train is "in" ог "out" is on a tongue
which is magnetised by the magnet I² and deflected by its vicinity to two polar
extensions P of the electro magnet P. The two screens S³ and S³ have their move-
ments rendered dependent on each other by a hook of $2 engaging a pin on S³ as
shewn in Fig. 7. In this position S2 shewing tablet " out," shewing tablet
"in" cannot move, but when S2 descends to shew tablet "in" S3 is left free to
shew either "in "
or "out," and when it remains shewing "out" S2 is free to shew
" in " 16
or out" without affecting S³.
Assuming that there are two stations X and Z at the extremities respectively of a
section of the line each having a set of the apparatus described above and a local
battery, the poles of which may be named respectively + or carbon, and-or zinc,
and that the ordinary telegraphing line wire W extends from the one station to the
other, then the battery, the line wire, and earth being connected to the various
contacts as shewn by Fig. 9, the operation of the apparatus may be described as
follows: X desiring to send on a train towards sends a preconcerted signal to Z
by using his bell plunger and Z replies. If the section of line be clear, that is to
say, if Z has received the tablet from a previous train sent from X and if Z has
issued no tablet to a train proceeding towards X after the last tablet acknowledged
by X to have been received, then Z by holding in his bell plunger for some time so
that the contacts made in the bell apparatus of X last long enough for the actuation
of his electro magnets, as X readily ascertains by seeing his index remaining
stationary deflected, then the local battery of X is thus brought in circuit with the
magnet E the catch E is lifted releasing the slide D2 which X can pull out with a
tablet in its recess. X can deliver this tablet to a departing train, but the act of
pulling out his slide with a tablet has so altered the electrical connections of his
apparatus that he cannot issue another tablet without going through a repetition of
his communications with Z.
The electrical connections of Z are also so affected that he cannot withdraw a
tablet without communicating with X but he can receive a tablet and when he has
received it and pushed in his slide with the tablet, this act releases his "tablet in"
plunger by pushing in which he restores the electrical connections to their normal
condition.
The apparatus may be operated as described to suit various conditions of traffic.
For example, X may issue tablets to several successive trains but only under the
condition that he cannot issue a second until X has received the first and restored
the connections to their normal condition. Or again X can issue a tablet to a train
which without going to may pass through a siding or elsewhere and return to X
but while the tablet so issued by X remains out, X cannot release the apparatus so as
to enable Z to issue a tablet.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim in respect of apparatus for ensuring safety of traffic on single lines of
railway is
1. The use in combination of the tablet receiving and issuing apparatus A the
bell signalling apparatus B and the electrical communicating apparatus C substantially
as described.
2. The tablet receiving and issuing apparatus, substantially as described with
reference to Figs. 2 to 5 inclusive.
3. In the bell signalling apparatus in combination with the vibrating armature M¹

page_text: and rod M2 the contact springs M³ and M having different periods of vibration
substantially as described with reference to Fig. 6.
4. The combination of the tablet plunger T its stop gear and magnet T¹ Tº T³ Tª T³ Tº
with the release rod L and the gear L L and G connecting it to the tablet slide
substantially as described with reference to Figs. 2, 5, and 8.
5. The electrical apparatus and connections substantially as described with reference
to Figs. 7, 8 and 9.
ABEL & IMRAY,
Agents for the Applicant.