Iм- PROVEMENTS IN SWITCH LOCKS FOR RAILWAYS
Year: 1879

page_text: LETTERS PATENT to Joseph Tomlinson, junior, of No. 160, Alexandra Road,
St. John's Wood, in the County of Middlesex, for the Invention of "Iм-
PROVEMENTS IN SWITCH LOCKS FOR RAILWAYS."
"
PROVISIONAL SPECIFICATION left by the said Joseph Tomlinson at the
Office of the Commissioners of Patents on the 3rd January 1879.
"
JOSEPH TOMLINSON, junior, of No. 160, Alexandra Road, St. John's Wood, in
the County of Middlesex. IMPROVEMENTS IN SWITCH-LOCKS FOR RAILWAYS."
In the Specification of a Patent granted to James Livesey, John Edwards, and
William Jeffreys, on the 27 February 1867, No. 547, were described means of
locking or securing the switches or points of railways during the passage of trains
over them by the use of a bar which can not be moved while any part of a train is
over it, and in the Specification of a Patent granted to John Saxby and John
Stinson Farmer on the 25th February 1870, No. 569, was described the combination
of such switch locking bar, with a bolt or its equivalent for farther securing the
points, and also for controlling the signals relating thereto. In the working of the
apparatus last referred to it may happen that owing to accident to the rods for
working the points they fail to be moved as intended, but nevertheless the locking
bar and its bolt can be moved, and thus a signal may be given for passage of a train
to the wrong line.
My Invention relates to an arrangement of such locking bars and bolts or their
equivalents in combination with a set of points, so that if the points should fail to
be moved as intended the signalman is at once apprised of the failure and provented
from giving signal for passage of a train except along that line for which the points
are properly set. For this purpose I apply at a set of points a pair of the locking
bars of the kind referred to, each provided with a bolt or its equivalent, and each
connected by suitable rods to a separate lever in the signal box, the one set consisting
of lever, rods, bar, and bolt or its equivalent, being appropriated to the locking of
the points in position for main line traffic, and the other, set in like manner, being
appropriated to the locking of the points in position for branch line traffic. Thus
if the signalman desires to set the points and give the signal for passage of a train
along the branch, but if the points fail to be moved as he desires for this purpose,
he will be unable to move the lever which works the branch line, bar, and bolt; he
will therefore be informed that the working of the points has failed, and the bolting
lever being interlocked with the signal levers, he will be unable to give the signal

page_text: for passage of a train to the branch. And in like manner a failure in setting the
points for the main line will become known to the signalman and prevent him from
giving the signal for passage to that line.
The bolts which I prefer to use are of the kind described in the Specification
No. 569 of 1870 referred to above, each bolt being in the form of a plunger, which
shoots into a hole in a crossbar connecting the two shifting point rails, holding them
firmly when it is so shot, but which cannot be so shot unless by the proper move
ment of the shifting rails the hole for the reception of the bolt is brought exactly
to face it. The cross bar referred to may be made in two pieces, one attached to
each of the shifting point rails, the two pieces overlapping each other in the parts
where the bolt holes are made in them. Thus if either of the switch rails should
by accident fail to be moved as desired in shifting the points, one or other of the
holes in the overlapping cross bars will not be presented truly to the bolt which it is
intended to receive, and the signalman, being in such case unable to shoot the bolt,
will be apprised of the failure in the due movement of the points, and will be
prevented from giving the signal for passage of a train.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Tomlinson in the Great Seal Patent Office on the 28th
June 1879.
JOSEPH TOMLINSON, junior, of No. 160, Alexandra Road, St. John's Wood, in the
County of Middlesex. "IMPROVEMENTS IN SWITCH LOCKS FOR RAILWAYS."
In the Specification of a Patent granted to James Livesey, John Edwards, and
William Jeffreys, on the 27th February 1867, No. 547, were described means of
locking or securing the switches or points of railways during the passage of trains
over them by the use of a bar which can not be moved while any part of a train is
over it, and in the Specification of a Patent granted to John Saxby and John
Stinson Farmer on the 25th February 1870, No. 569, was described the combination
of such switch locking bar with a bolt or its equivalent for farther securing the
points and also for controlling the signals relating thereto. In the working of the
apparatus last referred to it may happen that owing to accident to the rods for
working the points they fail to be moved as intended, but nevertheless the locking
bar and its bolt can be moved, and thus a signal may be given for passage of a train
to the wrong line.
My Invention relates to an arrangement of such locking bars and bolts or their
equivalents in combination with a set of points, so that if the points should fail to
be moved as intended, the signalman is at once apprised of the failure and prevented
from giving signal for passage of a train except along that line for which the points
are properly set. For this purpose I apply at a set of points a pair of the locking
bars of the kind referred to, each provided with a bolt or its equivalent, and each
connected by suitable rods to a separate lever in the signal box, the one set, con-
sisting of lever, rods, bar, and bolt or its equivalent, being appropriated to the
locking of the points in position for main line traffic, and the other set in like
manner being appropriated to the locking of the points in position for branch line
traffic. Thus if the signalman desires to set the points and give the signal for
passage of a train along the branch, but if the points fail to be moved as he desires
for this purpose, he will be unable to move the lever which works the branch line,
bar, and bolt, he will therefore be informed that the working of the points has
failed, and the bolting lever being interlocked with the signal levers, he will be
unable to give the signal for passage of a train to the branch. And in like manner
a failure in setting the points for the main line will become known to the signalman,
and prevent him from giving the signal for passage to that line.
The bolts which I prefer to use are of the kind described in the Specification
No. 569 of 1870, referred to above, cach bolt being in the form of a plunger, which
shoots into a hole in a cross bar connecting the two shifting point rails, holding them
firmly when it is so shot, but which cannot be so shot unless by the proper move-
ment of the shifting rails the hole for the reception of the bolt is brought exactly
to face it. The crossbar referred to may be made in two pieces, one attached to each
of the shifting point rails, the two picces overlapping each other in the parts where
the bolt holes are made in them. Thus if either of the switch rails should by
accident fail to be moved as desired in shifting the points, one or other of the holes
in the overlapping cross bars will not be presented truly to the bolt which it is
intended to receive, and the signalman being in such case unable to shoot the bolt
will be apprised of the failure in the due movement of the points, and will be
provented from giving the signal for passage of a train.

page_text: shifting point rails worked by the rod b; C, C', are locking bars of the kind
described in the Specifications above referred to, worked by rods c, c¹, through bell
crank levers D, D¹. Those bell crank levers have each a third arm linked by rods
d, d', to plunger bolts E, E', which work in a guide block F and shoot into holes in
cross bars G, G¹, that are connected to the shifting rails B, B1, and overlap each
other where they pass through the guide block F. The two bars G, G', might be
nade in one piece, but by making them as separate bars overlapping each other, as
shewn, the failure of movement of either of the shifting rails B, B', is detected
even if the other has moved as desired. The points as shewn in the plan, Fig. 1,
may be considered as being set for the main line of rails and secured in that attitude
by the bolt E being inserted in the holes of the overlapping cross bars G, G¹. The
other bolt E' cannot in this case be inserted, because there are no holes in the bars
G, G', facing it. The levers which: work the rods c, c¹, are interlocked with the signal
levers in such manner that the signals for passing a train along the branch line
cannot be given. As a train signalled to advance passes over the locking bars C, C',
the flanges of its wheels prevent these bars from being moved, as described in the
Specification No. 547 of 1867 above referred to, and consequently prevent any
alteration of the parts of the bolting apparatus and of the rods c, c', which work
them until the last wheels of the train have passed the locking bars. If now it be
desired to shift the points from the main line to the branch the bolt E is first with-
drawn by the movement of the rod c, which movement, by means of interlocking
gear locks the main line signals; the points are then shifted by the movement of
the rod b, and if they obey that movement and come fully home they are secured
by the shooting of the bolt E¹, effected by the movement of the rod c¹, and this
movement has the effect of unlocking the signals for the branch line, which thus,
until the points are fully secured, cannot be given. If through any accident one of
the point rails B, B₁, should fail to obey the movement of the rod b, then the
bolt E cannot be shot, and consequently the rod c¹ cannot be so moved as to release
the signals. Thus the signalman is apprised by the impossibility of shooting tho
bolts E or E' if either or both of the point rails B, B', has failed to obey the
movement for shifting them.
Having thus described the nature of my Invention, and in what manner the same
is to be performed, I hereby declare that I make no general claim to the use of
point locking bars C, C', nor bolts E, E', connected therewith, but I claim,―
The combination at a set of railway points of two sets of point locking bars and
bolts, each set worked independently of the other, substantially in the manner and
for the purposes herein set forth.
In witness whereof, I, the said Joseph Tomlinson, junior, have hereunto
set ny hand and scal, this Twenty third day of June, in the year of our
Lord One thousand eight hundred and seventy ninc.
J. TOMLINSON, JR. (LS.)