Year: 1887

page_text: Date of Application, 13th Junė, 1887
Complete Left, 16th Feb., 1888
Complete Accepted, 29th Mar., 1888
I, JOHN PATRICK O'DONNELL of Cambridge Villa, Cambridge Road, New Malden
in the County of Surrey Signal Engineer and Patent Agent do hereby declare the
nature of this invention to be as follows:-
My invention has reference to obtaining further, and more definite protection in
Traffic movements upon Railways, by means of my improved system of interlocking
the levers in the Signal Cabin.
It is customary for instance at the present time, to either directly lock all
conflicting points, by the respective Signals; or directly lock all conflicting points,
by any Facing point Lock or other Bar lever, whose Bar may be fixed, either
intermediate or beyond the fouling points.
It is obvious the former case affords no absolute protection whatever for points at
a distance, while the latter case, is most costly and causes great inconvenience to
shunting operations-With my improved system of locking, I remedy this by leaving
all fouling points and Bars, normally free of each other, but when the respective
Signal has been lowered (the Bars having previously released the Signal) although
the Signal may be immediately replaced to Danger, still the conflicting points are
held locked until the Bar lever, has been replaced to its normal position.
I effect this result by mechanisın similar to that described and shewn in the
Specification of Letters Patent granted to me on March 1st 1886 and numbered 2911,
the present invention being a further developement of that invention.
I am aware that various examples of special safety locking, have been from time to
time tried, and in order therefore to mark the distinction, between my present
improvements and existing or prior experiments or examples. I will briefly describe
the essence of this present invention as follows-
It consists on the one hand in allowing perfect freedom between any two or more

page_text: levers in their normal position, but ensures that upon the intervention of a third
lever, which ever of the former has been worked must be replaced to its normal
position, before the other lever or levers, is or are free to be actuated, and on the
other band it ensures that any two or more levers, shall lock each other in their
normal position, but upon the intervention of a third lever; the locked lever or levers
of the former, becomes or become free to be actuated.
This locking is effected by tappets without the aid of side movement.
Sometimes I arrange the aforesaid Special Rotation Locking in conjunction with
the Passenger Signal and Signal for shunting movements which refer to the same
line of Railway, that is I provide an arm or Disc underneath the Stop or other Signal,
specially for Drawahead or shunting purposes, in order to allow absolute freedom for
the latter and to ensure the most perfect safety for Passenger movements.
;
Dated this 13th day of June 1887.

page_text: COMPLETE SPECIFICATION.
Improvements in Interlocking Levers in Railway Point and Signal
Apparatus.
1, JOHN PATRICK O'DONNELL of Cambridge Villa, Cambridge Road New Malden
in the County of Surrey Signal Engineer and Patent Agent do hereby declaro 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 :-
My invention has reference to obtaining further and more definite protection in
Traffic movements upon Railways, by means of my improved system of interlocking
the levers in the Signal Cabin.
It is customary for instance at the present time, to either directly lock all
conflicting points by the respective signals or directly lock all conflicting points, by
any facing point lock or other Bar lever, whose Bar may be fixed either intermediate
or beyond the fouling points.
It is obvious the former affords no absolute protection whatever for points at a
distance while the latter case causes great inconvenience to shunting operations.
With my improved system of locking, I remedy this, by leaving all Fouling points
and Bars normally free of each other, but when the respective Signal has been
lowered (the Bars having previously released the Signal) although the Signal may
be immediately replaced to danger, still the conflicting points are held locked; until
the Bar lever has been replaced to its normal position.
Figure 1 is a single line sketch of a Signalling Section, three Lines of Railway in
one direction and three in the other direction. The numbers in all Figures represent
the levers; and tappets attached to such levers, in the Signal Cabin set apart for
working the respective points, Signals, and safety or Locking Bars. Sufficient only
howover ure shewn to illustrate the novel method of interlocking.
Figure 2 is also a Single Line sketch of a Signalling section, but is introduced
to illustrate my method of locking by means of Bars 13, 14, 18, 19.
Figure 3 is a plan of a locking case (with cover removed) through which the
tappets slide, the said tappets being actuated, by the respective levers, to which they
aro attached.
These tappets are provided with notches (the square notches m, p, s, t, u, w, x, y,
or equivalent pawls, teeth or ribs, are necessary for my novel mode of interlocking,
I therefore call them Rotation Tappets) which free the movements of, or are locked
by certain locking pieces.
In Figure 1, the middle arm No. 4 of the three arm bracket post applies for trains
from A to B. Before however this lever 4, can be worked, to deflect the said arm,
it is necessary that the crossing points worked by levers 22. 23. 25 should be moved
over, and again it is further necessary that the Facing points should be bolted by
moving over levers 21. 24. 26. 28 which work the Facing point locks.

page_text: In large Stations and busy yards, where shunting is carried on to any extent,
especially where Fly shunting is necessary, it is extremely inconvenient to make
points lock each other.
It is therefore usually effected by making the respective Signals lock the necessary
points. It will be seon however that little real safety is ensured by the latter method,
as when the signal is replaced to danger (that is to say when the back lock is taken
off the releasing points and point lock levers) all levers are free to be moved.
In following the Traffic movement in Figure 1 (the facing points 27 are some
200 yards or more from the Signal No. 4) it will be understood that upon the
signalman replacing lever No. 4 to danger, immediately the train arrives at it, he is
at liberty and has ample time to replace levers 28-27 possibly splitting the train
as it arrives at the latter points. The signalman can also open either of the
crossings 32. 40. 42. and so make the roads for any movement through them.
Under most conditions it is not desirable that point lock levers should release each
other, and again it is still less desirable as previously mentioned that bar levers should
directly lock point levers, it is therefore to overcome these inconvenient and sometimes
dangerous systems, I have arranged my novel mode of interlocking.
In the matter of Signal No. 4 it has no direct interlocking with points 82. 40. 42,
neither have the point lock levers 21. 24. 26. 28. any connective releasing with each
other, that is to say they are normally free of each other. When however the said
Signal No. 4 is released and deflected, my novel method of locking compels the point.
lock levers 21. 24. 26. 28. to be replaced in a certain rotation as will be hereinafter
described which has the effect as far as safety is concerned as though facing points 27
were situated at Signal No. 4.
Again with respect to the crossing points 32. 40. 42. they cannot be moved unless
point lock lever 28. has been replaced. Normally point lock lever 28 does not lock
crossing points 32. 40. 42. until signal No. 4 has been lowered.
It is obvious then that any possible combinations of shunting movements may take
place, points and point lock being normally quite free of each other, and it is only
when a passenger signal has been lowered that my novel mode of safety (otherwise
Rotation) locking comes into operation.
I will now describe the action of the locking mechanism necessary to effect the
desirable result reference being made for that to Figure 3.
Before tappet 4 is free to be moved forward the notch V of tappet 28 must be
moved in front of lock c¹, notch r of tappet 26 must be moved in front of lock d³,
notch m of tappet 24 must bo moved in front of lock d, notch K of tappet 22 must
be moved in front of lock f¹, notch of tappet 23 must be moved in front of lock f³,
notch of tappet 21 must be moved in front of lock d', notch n of tappet 24 inust be
moved in front of lock e', notch O of tappet 25 must be moved in front of lock ³, and
square notches u ands of tappets 26. 28 must be moved in front of locks e and d
respectively.
T locks a and b are loose and held in position for locking lever 4 normal by
locks a¹, a², 61, 62.
1
Locks a¹ c3, c, c, c, which we will call top locks are connected together, by
one slide; locks, d² (bottom locks) are connected together by another slide, and
locks and d₁ are also connected to a separate slide, the two latter slides but
together under the tappet 24. All these locks work in one channel Z.
"
Locks a, e, e (top locks) are connected together by one slide; and locks bff, /*
(bottom locks) are connected together by another slide, these sets of locks work in
channel .
When tappets 21. 22. 23. 24. 25. 26 27 and 28 have been moved forward and
tappet 4 also moved, then tappet 28 cannot be moved back, until tappet 26 has first
been replaced, tappet 26 cannot be replaced, until tappet 24 has first been replaced,
tappet 24 cannot be replaced until tappet 21 has first been replaced, because when
tappet 4 moved forward, it placed square locks in the notches u, s, m, of tappets 28.
26. 24 and these locks can only be moved out of the said notches by bevel locks
actuated by the other tappets and levers,

page_text: In the same way when tappet is moved forward it places square locks in
notches c³, c, c, c of tappets 27, 32, 40, 42 respectively thereby effectually locking
these tappets until tappet 28 has first been replaced.
The system of safety locking in Figure 2 is carried out in a similar way, as that
previously described with reference to Figures 1, 3, and tappets 4, 28, 32, 40, 42.
The interlocking of levers 4, 19, 20, 40, 42. Figure 1 is also similarly effected.
The ordinary back and front locks, effected, by the bars levers upon the facing
point levers are added, although my method of interlocking effects the same result,
by the square notch, rib, tooth or the like. This novel method of interlocking is
effected as will be seen, without the aid or necessity of side movement or slip action
of tappet.
Sometimes I arrange the aforesaid Special Rotation Locking in conjunction with
the passenger signal and shunting signal, which refer to the same line of railway,
that is I provide an arm, or disc (underneath the Stop or other Signal,) specially
for draw a head or shunting purposes, in order to allow absolute freedom for the
latter; and to ensure perfect safety for passenger movements.
I am aware that various examples of so called special safety locking have been
from time to time tried, and in order therefore to mark the distinction, between my
present improvement and existing or prior experiments or examples, I will briefly
describe the essence of this present invention as follows.
It consists on the one hand in allowing perfect freedom, between any two or more
levers in their normal position, but ensures that upon the intervention of a third lever,
which ever of the former has been worked, must be returned to its normal position,
before the other (of the former) is free to be actuated, and on the other hand, it
ensures that two or more levers shall lock each other in their normal position, but
upon the intervention of a third lever the locked one of the former becomes free.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim
In Interlocking apparatus for Railway Signals, points, and bars, the use of tappets,
actuated through any medium whatever, without or in conjunction with teeth, ribs,
or the like, for the purposes of effecting my novel method of interlocking, substantially
as herein described.