Improvements in Electrical Apparatus for Controlling Traffic on Single Lines of Railways.
Year: 1896

page_text: Date of Application, 20th Oct., 1896-Accepted, 21st Nov., 1896
COMPLETE SPECIFICATION.
Improvements in Electrical Apparatus for Controlling Traffic on
Single Lines of Railways.
A communication from abroad by JOHN WELLS WAINWRIGHT HOPKINS, Civil
Engineer, of the Firm of Hopkins, Gardham and Tetley, Railway Engineers
and Contractors, Buenos Aires, in the Argentine Republic.
I, JOHN PATRICK O'DONNELL, of Fingal, Bromley, Kent, Civil 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:-
The objects of my invention are to electrically control traffic on single lines of
railway so that more than one train may proceed, say from A to B, in succession,
the second and succeeding trains not being delayed for the arrival of the first
at B; on the other hand, although a succession of trains may proceed from A to B
no train can proceed from B to A until the last train despatched from A has
arrived at B and the visual signal or staff or its equivalent, which the driver carries,
is inserted in its proper place in the staff instrument at B.
1 arrange at each station, A and B for example, an instrument which is designed
to contain the specified number of staffs or visual authorities according to the
largest number of trains which would be sent in one direction, without any return
trains from the other direction.
For the purposes of explanation I will assume that each instrument is supplied
with six staffs so that if six trains are sent from A there would be 12 holes
in the instrument at B, six to receive the six additional staffs sent from A in
addition to the six already provided; it will thus be possible to send 12
trains from B to A.
I arrange that, assuming the instruments to be normal and A desires to send a
train to B, A is inoperative and cannot send a train to B unless sanction is given
by B; B gives his sanction by operating his releasing plunger by which action a
spring makes an electric contact and a current is sent along the line wire from B
to A, and A having moved his staff opposite the stationary releasing magnet
(I will take for example No. 1 staff), the current travels in the direction of A and
energizes the magnet the latter in turn withdraws a pawl from notches in the upper
side of the staff and the staff is then ready to be withdrawn. In the act of with-
drawing the staff a lever keyed to the commutator spindle is operated by being
moved out of another notch in the upper side of the staff which action through the
commutator being moved breaks the line circuit from B to A so that no staff can
be withdrawn from B in the direction of A. Further when A has withdrawn the
staff the indicator at B is moved from blank to "1" indicating that No. 1 staff has
been withdrawn.
In order that my invention may be better understood and more readily carried
into effect I will describe it with reference to the accompanying drawings, in
which-
Figure 1 is a front view of the instrument.
Figures 2 and 3 are right and left hand side views showing the internal
mechanism.
Figure 4 is a front view through section line A-A of Figure 2.
Figure 5 is a front view through section line B-B of Figure 2. This figure

page_text: Figure 6 is a plan of the instrument with the top portion of the casing
removed.
Figure 7 is a diagram of two instruments, one at A and the other at B, and the
electrical connections.
The same numbers refer to the same parts in the several figures of the
drawings..
1 is the revolving barrel for staffs working about a centre 2, 3 is a metal plate
with a notch 4 through which the staffs must pass in withdrawing from or inserting
into the said instrument. 5 is the indicating dial showing the number of staffs
taken out of the corresponding instrument at the other end of the linewire. 6 is
the plunger for releasing the staffs and 7 is a plunger for ringing the bell.
8 (Figure 2) is the staff shown in its locked position in the instrument, 9 is the
lock and 10 are the locking coils. 11 is the polarized relay, 12 is a commutator
worked by the withdrawal and insertion of the staff, 13 is a spring stop which keeps
the revolving drum in position, 14 are the bell parts, 15, 16, 17, 18 and 19 (Fig. 6)
are the springs working in connection with the commutator 12, 20 and 21 are metal
plates fixed to the commutator 12, and which come into connection or break
connection as the case may be when the commutator is moved, 22 (Figs. 2 & 3) is
an arm fixed upon the commutator spindle, 23 is the roller on the said arm operated
by the withdrawal or the insertion of the staff 8, 24 (Fig. 6) is a pressure spring
resting upon a flattened surface of metal 25 which is fixed to the commutator
spindle 26 and holds it in position; the spring 27 also helps to keep the commutator
in the position shown. 28 is an arm on the commutator spindle 26, 29 is a spring
under said arm normally resting on a projection of bar 30 so that when the staff 8
is inserted the commutator spindle with its arm 28 is moved downwards taking the
bar 30 with it and actuating the indicator dial 5. 31 (Fig. 5) is an electro-magnet
working in connection with the indicator 5, 32 is an arin upon which a pin 33 is
fixed the said arm being connected by links 34 to electro-magnet 31, the arm 32 is
centered on pinion 35 and a spring 36 holds the arm 32 on to stop 37; below this
pinion 35 is another 39 with an arm 40 and pin 41, this arm has attached to it a
contact, spring 42 which normally rests on contact 43 and when moved upward
upon contact 44; upon the extremity of the arm 40 is an inclined piece 45, 46 is
an armature, 47 is a roller on said armature, 48 is a spiral spring holding the
armature in position shown. 49 are electro-magnets operating armature 46, in
front of the armature 46 is the plunger spindle 6 the pressing in of which forces
the armature 46 to magnet 49 and actuating the arm 40 by means of the inclined
piece 45, 50 and 51 are toothed wheels fixed upon spindle 52, the teeth being
arranged in opposite directions, the said wheels being operated by pins 33 and 41
upon levers 32 and 40.
53 is a star wheel fixed upon the spindle 52. 54 is a
hatchet shaped piece testing between the teeth of the star-wheel and centered
at 5, the object of this piece is to keep the wheel and the spindle in certain fixed
positions. The spring 56 tends to hold the hatchet piece down firmly. 57 is a
spring fixed to the bar 30, and normally stands just above the arm 32, the
spring 58 (Figs. 2 & 3) keeping it in this position. The bar 30 is moved down-
ward by the operation of inserting a staff; the arm 22 is thrust inward by the end
of the staff, revolving the commutator spindle and with it the spring 29 and its
stop 28, forcing down the bar 30 by means of its lower projection. This operation
would force downward the arm 32 and its pin 33, revolving the toothed wheel 51
one tooth. 59 (Figs. 4 & 6) is an ebonite wheel fixed upon the indicator dial
spindle; 60 is a spring; 61 is a rounded piece fixed to the spring; 62 is another
contact spring normally in connection with spring 60. The piece 61 is shown
resting in a recess in ebonite wheel 59. When the ebonite wheel is moved by
plunging the lock plunger 6 the spring 60 is forced upward by means of the rounded
piece 61 thus breaking connection with spring 62.
The working of my invention is as follows:-
Assuming the instruments to be normal, starting signals (if any) in their
normal danger" position and the staffs in the instruments, and that a train has

page_text: to be sent from A to B; A, normally, is not free to withdraw a staff. A first
calls up on the bell and asks sanction of B and B replies by the same signal. (This
however, has no particular reference to my invention as it is usual with the
ordinary train signalling.)
A having asked permission, B plunges or presses in plunger 6 which operates
armature 46; the roller 47 engages with incline 45 pressing upward the arm 40
and pin 41 engages with the toothed wheel 50 revolving it half a tooth; by this
time the armature 46 has arrived on the poles of the electro-magnets 49 and is
held there by an electric current. When this movement has taken place the.
indicator dial 5 will show blank in B's instrument, having moved from 0.
B having given permission a current is set up from battery 63 (Fig. 7), through.
electro-magnets 49, contact 44, spring 43", (Figs. 3 & 7), to spring 15, plate 21,
spring 16, terminal (1) and to the line wire. The current enters terminal (1).
of A's instrument going through spring 16, plate 21, spring 15 and contact
spring 43, contact 43 to spring of bell plunger 7, contact 64, through polarized
relay 11 to earth at terminal (6). The armature of relay 11 makes contact
with 65. The signalman at A in withdrawing the staff turns the commutator 12
and the plate 20 and joins the springs 18 and 19; this operation enables a current
to flow from battery 66, through locking coils 10, spring 60, contact 62, back to
the tongues of polarized relay 11, thus completing the circuit and raising the lock
piece 9 free of the staff 8.
I have herein before mentioned that in giving permission B's indicator shows
blank, but directly A withdraws a staff when the staff 8 is clear of the lock piece 9.
the circuit between A and B is broken down in the following manner-The
commutator 12 and its metal piece 21 are so arranged that directly the staff is
withdrawn the springs 15 and 16 are clear of the plate 21 and are only resting on.
the insulation of the commutator; this has the effect of breaking the current and
allowing the armature 46 in B's instrument to fall to its normal position, the
arm 40 drops by gravity and the toothed wheel which has been keeping the
indicator in the position showing blank through the dial is allowed to complete its.
movement thus changing the indicator from "blank" to "1," by the hatchet
shaped piece 54 being normally on the edge of the teeth immediately behind it.
When said hatchet piece falls it moves the star wheel forward until the V shape
of the hatchet fits in between the teeth, this completes the motion to show the next
number on the dial to the previous one, for instance, if the previous indication
was "O" it would complete the motion to indicate "1." The motion to indicate
is really in two movements, one, mechanical indicating from "0" to "blank" and
the second, electrically as herein described through the hatchet shaped piece 54
dropping, completing it from "blank" to the next number.
The staff is taken to B in the usual way and inserted in B's instrument, the
following action taking place:-Upon inserting the staff in the instrument its end
comes in contact with the rolier 23, the spring 29 depresses the slide bar 30 its
upper projection and spring 57 engaging with the arm 32, the pin 33 is forced
downward revolving the wheel 51 and reversing the indication of the dial
from "1" to "0."
Should the signalman at A after withdrawing the staff find it necessary to
replace it in his own instrument the following action will take place:-Upon
inserting the staff the end would engage with roller 23 and revolve the commutator
spindle 26 in the direction of the arrow, the plate 21 would move round and
connect the springs 16 and 17 thereby setting up a current from battery 67 at A
to terminal 1 at B, through spring 16, plate 21, spring 15, contact 43, bell
plunger 7 and contact 64, to polarized relay 11, electro-magnet 31, to earth (the
electro-magnet 31 taking the major portion of current) the armature of which is
attracted pulling down the arm 32 and forcing the pin 33 into the toothed wheel 51
revolving it backwards one tooth and changing the indication of the dial at B
from "1" to "0," thus restoring the instruments to their normal condition.
I wish it to be understood that I do not claim the principle of the permissive

page_text: train staff system, that is, sending a succession of trains in one direction no train
being able to proceed in the opposite direction until the whole of the staffs given to
the trains have been inserted in the instrument at the other end of the section, but
in such previous permissive train staff systems the details comprising the same
have not been found successful in operation. My invention therefore is for the
details comprising an instrument to effect in a workmanlike manner the desired
ends of a permissive train staff system, and
Having now particularly described and ascertained the nature of my inven
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In permissive train staff instruments for single lines of railways, the
combination of a revolving drum carrying the staffs and a fixed magnet operated
by the section in advance to release a staff when opposite the magnet, substantially
as described and illustrated in the drawings annexed.
2. In permissive train staff instruments for single line working, the combination
of apparatus substantially as described and illustrated for enabling a succession of
trains with a respective number of staffs withdrawn from the instrument, say at A,
to proceed to B, the whole of the staffs taken from A having to be either reinserted
in the instrument at A or B before any train can proceed in the opposite direction
from B to A.
Dated this 20th day of October 1896.
JOHN P. O'DONNELL, Fel. Chart. Inst. P.A.