Improvements in Railway Signaling Apparatus.
Year: 1886

page_text: Improvements in Railway Signaling Apparatus.
We, WILLIAM GRIFFITHS of 61 Sinclair Road, West Kensington Park, in the
County of Middlesex, Civil Engineer, and EDWARD THOMAS ROBERTS BRITTAIN
of 170 York Road, N. in the County of Middlesex, Signal Inspector, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to protect trains or vehicles at terminals, sidings,
or passing places, and to prevent a signal or signals being given to admit a second
train or vehicle on to a portion of line already occupied.
The apparatus employed is such that the proper signal for the departure of the
train or vehicle already on the protected line must be given, and the signal must
be returned to the danger attitude, before it will be possible to give the signal for
a second train or vehicle to pass on to the same portion of line.
In connection with the levers, locking apparatus is provided whereby a lever
that has been moved over to give a "line clear" signal, is prevented from being so
moved a second time until after the signal in advance has been lowered and
returned to the danger attitude.
The apparatus for this purpose is additional to interlocking apparatus of suitable
kind for preventing, as heretofore, the lowering of conflicting signals. Additional
locking apparatus such as above referred to is conveniently arranged as follows:-
Bars or plates connected to the levers are caused to operate interlocking bars
arranged at right angles to them for the purpose of preventing, as heretofore, the
giving of conflicting signals. These interlocking bars are caused to impart move-
ment in a vertical sense to other interlocking bars that are suitably formed to
engage as required with the bars or plates connected to the respective levers so as
to effect the locking of levers when these vertical moving bars occupy their lower
positions, and to release the proper lever or levers when the locking bars are raised.
Thus, let 1 be the starting signal for a train to cross from the down main line at a
terminal station on to the up main line and let 7 be the down uain line home
signal.
[r
In connection with the bars or plates of these two levers there is provided
a special locking bar that acts as follows:-Assuming both signals to be at
danger" and the points for crossing from the down main line to the up main
line to be open, the levers of the two signals being locked. On now moving over
the point lever to close the points so that a train may pass from the down line to

page_text: the up line, lever No.
will be, by ordinary means unlocked, lever No. 7 remaining
locked. On now moving over lever No. 1 to lower the signal for the train to pass
from the down line to the up, the special or vertically moving locking bar will be
raised clear of the bar or plate connected to lever 7, which, however, remains locked
by ordinary means.
The special or vertically moving locking bar will remain clear of lever No. 7
until it, after having been unlocked by ordinary means, on the return of lever 1
and the point lever, is moved over to lower the home signal. During this moving
over of lever 7 the special or vertically moving locking bar is permitted to descend
on to the bar or plate connected to the said lever, on which the said locking bar
rests until the lever is returned whereupon a notch or recess in the lever bar or
plate comes opposite a projection of the locking bar which thereupon descends and
automatically locks the lever, so that it cannot again be moved over until the
locking bar has been again raised out of gear by the moving over and returning
of lever 1 as before.
As will be evident, locking apparatus to operate on this principle may be
constructed in various forms and may be applied in connection with any number
of levers.
To ensure the return of the home signal to the danger attitude on the passing of
a train or vehicle, and to prevent its being lowered for a second train or vehicle to
pass until the portion of line in advance has been cleared, an arrangement as
follows is employed.
The signal operating lever is connected to a bar capable of longitudinal motion
in a suitable guide or guides under the action of the lever and a counter-balance.
The guides, which may be in various forms, are connected in some suitable
manner to and are controlled by a treadle bar. In one arrangement the guides are
in the form of links, with anti-friction rollers between which the bar can slide, the
links being carried by radius bars and bell crank levers connected to the treadle
bar. In a modification slotted standards form the guides and the sliding bar is
supported by radius rods or fingers carried by rocking shafts. The sliding bar
carries a pawl which normally engages with a bar or plate connected to the sema-
phore arm or signal, so that if the signal lever be pulled over thereby causing the
sliding bar to move longitudinally, the signal will be lowered.
"
But assuming the treadle bar to be depressed by a passing train or vehicle, the
sliding bar will be moved vertically or laterally, so that its pawl will release the
plate or bar connected to the signal, which will thereupon assume the "danger
attitude as usual, and the plate or bar connected to it will be moved into such a
position that the pawl of the sliding bar cannot again engage it until after the
signal lever has been returned so as to become locked by the means already
described.
In a further modification the sliding bar connected to the signal lever is arranged
in connection with a pair of longitudinal guide bars supported by radius bars and
connected to the signal, the sliding bar connected to the lever being supported at
one end by a link connected to a radius bar and carried by a rocking shaft, and
at the other end by an antifriction roller. The rocking shaft is connected to aud
operated by the treadle bar.
Normally, a part of the sliding bar engages with a pin (provided with anti-
friction roller) between the guide bars so that longitudinal movement of the
sliding bar, produced by pulling over the signal lever, will be imparted through
the guide rods to the signal, which will be lowered. If, however, the treadle be
depressed, the sliding bar will be disengaged from the guide bars, the signal will
assume the "danger" attitude, and re-engagement of the sliding bar with the guide
bars will not be effected until the lever has again been returned. The treadle bar
is returned to its normal position, after the passing of a train or vehicle by a weight,
counterbalance or spring.
Releasing gear such as above described may also, in some cases, be applied
with advantage where it is desired to use one lever for working several shunting

page_text: signals, as, for instance, at large terminal stations, thus avoiding multiplication of
levers in the cabin.
At a station or passing place we furthermore provide a train bar or bars in
connection with suitable locking mechanism so applied as to control, by means of
the train bar, the whole of the conflicting signals; the arrangement being such
that the train bar is connected directly with locking mechanism applied to the
lever frame, so as to lock the levers as required, independently of the connections
whereby the levers operate the signals. With such apparatus, assuming, for
example, that, in the case hereinabove given by way of illustration, the points had
been closed, the signal lowered for a train to cross over from the down main line
on to the up main line, and afterwards the signal had been returned to the
danger attitude and the points again opened, but that the train or vehicle
which should have crossed over remained on the down line; its presence there
would prevent the lowering of the home signal to admit a second train or vehicle
on to the same portion of line.
"
»
An arrangement for locking the signal lever or levers by a train bar, as described,
is as follows:-When the train bar is depressed, it, through suitable connections,
causes the engagement of a locking lever with the signal operating lever, the dis-
engagement being automatically effected by a weight counterbalance or spring when
the train bar is released.
An indicator connected to the locking lever shows when the signal lever is
locked.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicants.

page_text: Improvements in Railway Signalling Apparatus.
We, WILLIAM GRIFFITHS, of 61 Sinclair Road, West Kensington Park, in the
County of Middlesex, Civil Engineer, and EDWARD THOMAS ROBERTS BRITTAIN,
of 170 York Road, N., in the county of Middlesex, Signal Inspector, 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:
This invention relates to certain improvements in railway signalling apparatus
and comprises means for automatically locking a lever in its normal position when
it is returned to that position after having been moved over to lower a signal;
means for unlocking such lever by the operation of another lever; apparatus to be
operated by a passing train or vehicle to cause the return of a signal to the danger
attitude; and releasing gear for use where it is desired to employ one lever for
working several shunting signals, as for instance at large terminal stations, thus
avoiding multiplication of levers in the cabin also the invention relates to the
application at a station or passing place of a treadle bar or bars in connection with
peculiar locking mechanisin so applied as to control by means of the treadle bar or
bars the whole of the conflicting signals, the arrangement being such that the
treadle bar or bars is or are connected directly with locking mechanism applied to
the lever frame so as to lock the levers as required independently of the connections
whereby the levers operate the signals.
:
One object of this invention is to protect trains or vehicles at terminals, sidings,
or passing places, and, where so desired, to prevent a signal or signals being given
to admit a second train or vehicle on to a portion of line already occupied.
The apparatus can be so arranged and applied that the proper signal for the
departure of a train or vehicle already on a protected line must be given, and the
signal must be returned to the danger attitude, before it will be possible to give
the signal for a second train or vehicle to pass on to the same portion of line.
In connection with the levers, locking apparatus is provided whereby a lever
that has been moved over to give a line clear" signal, can be prevented from
being so moved a second time until after the signal in advance has been lowered
and returned to the danger attitude.
16
The apparatus for this purpose is additional to interlocking apparatus of suitable
kind for preventing, as heretofore, the lowering of conflicting signals. Additional
locking apparatus such as above referred to is conveniently arranged as follows:-
Bars or plates connected to the levers are caused to operate interlocking bars
arranged at right angles to them for the purpose of preventing, as heretofore, the
giving of conflicting signals.
These interlocking bars are caused to impart movement in a vertical sense to
other locking bars that are suitably formed to engage as required with the bars or
plates connected to the respective levers so as to effect the locking of levers when
these vertical moving bars occupy their lower positions, and to release the proper
lever or levers when the locking bars are raised. As will be evident, locking
apparatus to operate on this principle may be constructed in various forms and
may be applied in connection with any number of levers.
Referring to the accompanying drawings (Sheet 1) Fig. 1 is a side elevation, and
Fig. 2 a plan (with the cover of the containing box removed) of interlocking
apparatus according to this invention adapted for use with a set of operating levera

page_text: for controlling the starting signals 1, 3, and 4; home signals 6 and 7, and cross-
over points 2, 2 and 5, 5, at a terminal station, such as indicated in outline plan
at Fig. 18. Fig. 3 is a longitudinal vertical section on the line A. B. (Fig. 2).
Fig. 4 is a horizontal section on the line C. D. (Fig. 1). Fig. 5 shows in elevation
a lever frame with lever and interlocking apparatus. Figs. 6, 7, 8, and 9 are views
each representing in elevation and plan a locking bar according to this invention,
the four bars being marked respectively 1, 2, 3, and 4. Figs. 10, 11, 12, 13, 14,
15, 16, and 17 are similar views to Figs. 6 to 9 illustrating interlocking bars for
locking the signal and point levers in a manner well understood; they are marked
respectively 5b, 6º, A, B, C, D, E, F, those marked A, B, E, F, being provided with
means for imparting vertical movement to the locking bars 1b, 2, 3b, 4b respectively,
as will be hereinafter more fully described. Fig. 18 (Sheet 4) is a diagrammatic
view illustrating a double cross-over road and terminal station.
Referring to Sheet 1, 1*, 2*, 3*, 4*, 5*, 6*, and 7*, are bars or plates each con-
nected to and operated by a hand lever in a manner that will be readily understood
by reference to Fig. 5. These hand levers are respectively connected to and
operate or control the starting signal 1, (see Fig. 18), the points 2, 2, the starting
signal 3, the advance starting signal 4, the points 5, 5, and the home signals 6
and 7. The bars or plates 1 to 7 are interlocked where necessary to prevent the
lowering or showing of conflicting signals, or the placing of points in conflict by
the interlocking bars marked 5b, 6b, A, B, C, D, E, F, in a manner well understood,
and which separately considered forms no part of the present invention. These
interlocking bars are each provided with locking pieces 8, adapted to take into
notches 9 in the bars or plates connected to the levers. The interlocking bars 5b
and 6b are arranged above the bars or plates connected to the levers, while those
marked A, B, C, D, E, and F, are below them. They are at right angles to the said
bars or plates, and are capable of longitudinal movement. The locking bars 1b, 2b,
3b, and 4 are above the bars or plates 1* to 7*, and are each provided with locking
pieces or projections 10 adapted to engage with and lock the bars or plates 7*, 6*,
3*, and 1 respectively when they are in their lowest positions. The locking
bars 1, 2, 3, and 4b, are in the example shown caused to move in a vertical sense
by the ordinary interlocking bars A, B, E, F, for which purpose each of the
bars 1b, 2, 3, and 4b is provided with inclined surfaces 11, 11, adapted to take
upon and be operated by oppositely inclined surfaces 12, 12, carried by the
bars A, B, E, F. When either of the interlocking bars A, B, E, or F, is moved
longitudinally in one direction, its inclined surfaces 12 will cause one of the
locking bars 1, 2, 3b, or 4b, to rise clear of the bar or plate 7*, 6*, 3*, or 1*, as
the case may be, although such bar or plate may still remain locked in the ordinary
way by an interlocking bar or bars. When either of the interlocking bars A, B,
E, or F moves in the opposite direction, it allows one of the locking bars 1b, 2b,
3b, or 4, to again fall and lock a corresponding bar or plate connected to a signal
lever. Thus in the example illustrated, the locking bars when in their lower
positions effect locking as follows:-bar 1b locks bar or plate 7*, bar 2b locks bar or
plate 6*, bar 3b locks bar or plate 3*, bar 4 locks bar or plate 1*. 13, 14, are short
locking pieces not attached to either of the interlocking bars; they lock one or other
of the lever bars or plates between which they are situated in a manner well under-
stood. 15 is a box or frame for containing the locking and interlocking bars; it is
provided at opposite sides with openings or slots through which the bars or plates 1*
to 7* work. 16, 16, are fixed guide-pieces in the box or frame 15. The operation
of the just described apparatus as applied at a terminal station such as illustrated
in Fig. 18 (wherein 50 is the up line, 51 the down line, and 52 the station with
platform lines 53 and 54), is as follows:-Assuming that there are no trains in the
station or on the adjacent line sections and that it is desired to admit a train to
the platform, line 53, then the home signal 7 must be lowered. If the points 2, 2,
or 5, 5, be closed (as they are shown) this may be done because the previous pulling
over (to the position shown dotted in Fig. 5) and putting back (to the position
shown in full lines to-the right in Fig. 5) of the starting signal lever and its

page_text: The
connected bar or plate 1* will have raised the special locking bar 1b and unlocked
the bar or plate 7* that is in connection with the home signal lever. If, however,
either of the points 2, 2, or 5, 5, be open, then the bar or plate 7* will be locked
in the one case by the interlocking bar D and its connected locking piece 9* which
is arranged to slide in one direction on the bar D, or in the other case by the
locking piece 9* which will have been moved into locking position by the inter-
locking bar Gb at the time of moving over the point lever connected to bar or
plate 5* for opening the points. When the point levers are put back to their
normal positions (corresponding to the closed positions of the points) the home
signal can be lowered and the train permitted to pass. The pulling over of the
lever connected to bar or plate 7* moves the interlocking bar A to the right and
locks the bar or plate 1* and moves the sliding piece 9* to the left. This sliding
piece moves the interlocking bar 6b in the sanie direction and locks the bars or
plates 5 and 6*. When the train has passed the home signal 7, the lever connected
to that signal must be completely returned to its normal position whereupon its
connected bar or plate 7* will be automatically locked by the special locking
bar 1b. The train having passed to the platform line 53 if it be desired to give it
permission to cross over to the up line 50, the starting signal 1 must be lowered,
but this cannot be done until the points 2, 2, have been opened by pulling over the
lever connected to bar or plate 2*, because the bar or plate 1* is locked by the
locking piece 14. When the point lever connected to bar or plate 2* is pulled over,
it moves the interlocking bar D to the right, locking the bars or plates 3* 5* and 7*
and the levers connected to them. A notch in the bar or plate 2* is also brought
opposite the locking piece 14 so that the bar or plate 1* and starting lever
connected thereto can now be pulled over, and the starting signal 1 lowered.
pulling over of the lever connected to bar or plate 1* moves the locking piece 14
to the right and locks 2*. It also moves the locking bar F to the left, and further
locks the bar or plate 2* and the lever connected thereto and moves the inter-
locking har A to the left and raises the locking bar 1b from the notch in bar or
plate 7 but counterlocks this bar or plate. The train can now cross over to the
up line 50, and when it has done so the lever connected to the starting signal and
bar or plate 1* is returned to and automatically locked in the normal position
(signal at danger) by the locking bar 4b; this return movement of 1* releases the
counterlock from the bar or plate 7*. The lever connected to the points 2, 2, and
bar or plate 2* should then be put back to its normal position thereby moving the
.locking piece 14 to the left and locking the bar or plate 1* and the lever connected
to it moving the interlocking bar F to the right and raising the special locking
bar 4b from the bar or plate 1* and likewise unlocking the bar or plate 7* by
releasing the interlocking bar D. The advance starting signal would now be
lowered and the train be finally cleared away. The home signal 7 can now be
again lowered and another train be permitted to pass to the platform line 53. If
it be desired to permit a train to pass from the down line to the platform line 54,
the home signal 6 cannot be lowered to give such permission until the points 5, 5,
have been opened, since when they are closed the bar or plate 6* and the lever
connected to it are locked by the locking piece 13 as shown in Fig. 4. When the
points 5, 5, are opened by pulling over the point lever and so moving the bar or
plate 5*, a notch in the latter is brought opposite one end of the locking piece 13
and the bar or plate 6* is thereby unlocked. The same movement also causes the
interlocking bar 6b to move to the right and force the sliding piece 9* into a notch
in the bar or plate 7* thereby locking the lever of the home signal 7; it also moves
the interlocking bar 5b to the right thereby locking the bar or plate 3* and the
lever of the starting signal 3 in connection therewith. By now lowering the home
signal 6 by pulling over its lever and bar or plate 6* the locking piece 13 is forced
into the adjacent notch in the bar or plate 5* thereby locking the points 5, 5,
in their open position. The interlocking bar B is by the same movement moved
to the left so as to allow the locking bar 2b to rest upon the bar or plate 6* so
that when the said bar or plate 6* is returned by moving its lever to the normal

page_text: position, the locking bar 2b falls into a notch in bar or plate 6* and automatically
locks it and the lever connected to it in the normal position (signal at danger).
This takes place after the train has passed the home signal 6. By so returning the
lever connected to bar or plate 6*, the bar or plate 5* is unlocked, the locking
piece 13 being caused to enter a notch in the bar or plate 6*, when the point lever
and bar or plate 5* are put back to their normal positions. The train now at the
platform line 54 may be permitted to pass away to the up line by lowering the
starting signal 3 by means of its lever and the bar or plate 3* connected thereto.
This can be done since in clearing a previous train by the advance starting signal 4
the locking bar 3b will have been raised from the bar or plate 3*. The pulling
over of 3* moves the interlocking bar B to the right thereby raising the locking
bar 2 from the bar or plate (6*) but at the same time locking the latter 6* in the
ordinary manner. The train can then pass to the adjacent up line section, and,
when it has done so, the lever of the starting signal 3 is put back and is auto-
matically locked by the descent of the locking bar 3b and its engagement with 3*.
So long as the starting signal 3 remains lowered or off, the bars or plates 1* 2* 5*
and 6* are interlocked as well understood. To pass the train away on the up line,
the advance starting signal 4 is lowered. The pulling over for this purpose of the
lever connected to bar or plate 4* moves the interlocking bar E to the right, raises
the special locking har 3b from the bar or plate 3*, moves the interlocking bar F
to the left, and locks the bar or plate 2*. When the train has passed away, the
advance starting signal 4 is raised by putting back its lever connected to bar or
plate 4* and the bar or plate 2* is so unlocked. When the trains have been cleared
off, as hereinabove described, the several parts of the interlocking apparatus will
be in their normal positions corresponding to Figs. 2, 4, and 5.
Although we have described the locking bars as being actuated by longitudinally
movable bars that also act as interlocking bars, it is to be understood that vertically
movable locking bars for preventing a lever that has been moved over to give a
"line clear" signal from being so moved a second time until after the signal in
advance has been lowered may be employed in connection with any other known
or suitable arrangement of interlocking gear for preventing the giving of contra-
dictory signals, and the longitudinally movable bars whereby our vertically moving
locking bars are operated, may in such case be bars that are not specially formed
to effect interlocking, the interlocking gear being external to the box or frame
containing our improved locking apparatus.
As is well known, after a train has passed a lowered signal, it is the signalman's
duty to return his lever to its normal position in order that the signal may resume
the danger attitude. In order, however, to guard against accidents such as might
result from a neglect of this duty, it is advisable to provide, in connection with the
signal controlled by the lever that is provided with automatic locking mechanism
as described, means for ensuring the return of the signal to the danger attitude on
the passing of a train, whether the lever be returned to its normal position or not.
Thus, assuming a signal to have been lowered, and a train to have passed it, the
signalman will not be able to again lower the signal without previously returning
the lever to its normal position in which it will be locked until unlocked by the
operation of another lever. To ensure the return of the signal to the danger
attitude on the passing of a train or vehicle, an arrangement as follows is
employed:-
The signal operating lever is connected to a bar capable of longitudinal motion
in a suitable guide or guides under the action of the lever and a counter-balance.
The guides, which may be in various forms, are connected in some suitable
manner to and are controlled by a treadle bar. In one arrangement the guides
are in the form of links, with anti-friction rollers between which the bar can slide,
the links being carried by radius bars and bell crank levers connected to the
treadle bar. The sliding bar carries a pawl which normally engages with a bar or
plate connected to the semaphore arm or signal, so that if the signal lever be
pulled over, thereby causing the sliding bar to move longitudinally, the signal will

page_text: be lowered. But assuming the treadle bar to be depressed by a passing train or
vehicle, the sliding bar will be moved in a vertical sense so that its pawl will
release the plate or bar connected to the signal, which will thereupon assume the
"langer" attitude, and the plate or bar connected to it will be moved into such a
position that the pawl of the sliding bar cannot again engage it until after the
signal lever has been returned so as to become locked by the means already
described.
The treadle bar is returned to its normal position after the passing of a train or
vehicle by a weight counter-balance or spring.
The treadle
Fig. 19 is a side elevation, and Fig. 20 a plan of apparatus for causing the
return of a signal to the danger attitude on the passage of a train or vehicle with
the object hercin before mentioned. 17 is a double sliding bar; it is connected by
a bar 17* hinged to it, and a wire 18, to the signal lever, so as to be capable of
being moved by such lever longitudinally in one direction; it is also connected to
a counterbalance weight 19 for moving it in the opposite direction. This bar 17
is carried by two pairs of guide links 20, 20, each provided with anti-friction
rollers at 21, 21, between which it can slide. One end of each pair of guide links
is carried by one end of a radius rod 22 pivotted to standards 23, the other ends of
the links being connected to bell crank levers 24. These levers 24 are connected
by rods 25, 26, lever arm 27, and a weigh-shaft 28, with a treadle bar 29, arranged
at the inner side of one of the rails and carried by pivotted arms 30.
bar is maintained in the raised or normal position shown in the drawings by
means of a balance weight 31* connected to the weigh shaft, which is connected
to the treadle bar by the pivotted arm 30*. 31 is a pawl pivotted to the sliding
bar 17, and situate between its two longitudinal members, the arrangement being
such that the pawl can rise but cannot assume a lower position than that shown in
the drawings. 32 is a second sliding bar arranged to move through guides in the
standards 23; it is connected at one end by a wire 32a to a counterweighted bell
crank lever 33 that operates the signal, and is provided with a pin or stop 34 to
limit its motion to the left. This bar 32 has a projection or shoulder 35 with
which the pawl 31 can engage when it is at the right hand side thereof as shown.
36 is an intermediate piece between the bars 25 and 26, and is provided with a
slot 37 and arranged to slide in a fixed block 38. 39 is a locking pin arranged to
slide in the said block 38 and connected at one end to one arm of a bell crank
lever 40, the other arm of which is connected by rod 41 to one arm of a weighted.
lever 42 pivotted at 43. The other arm of the lever 42 carries a pin that slides in
a slot in the bar 17*. As will be seen, the tendency of the weighted lever 42 is to
force the locking pin 39 through the fixed block 38 and through the slot 37 in the
intermediate piece 36 when this is brought opposite to it and this will be effected
when the rods 25 and 26 are caused to move sufficiently far in a longitudinal sense
by the depression of the treadle bar 29. By this arrangement the treadle bar
when depressed will be held in its depressed position and will be prevented from
rising and falling and thereby making a noise during the passage of successive
vehicles over it, whilst the slot 37 will compensate for any slight difference in the
depth of the different wheel flanges.
When the parts are in the relative positions shown in the drawings, if the
sliding bar 17 be moved to the right by operating the signal lever, the pawl 31
will cause the bar 32 to move with it, and lower the signal. When the train or
vehicle for which the signal was lowered passes over and depresses the treadle 29,
the links 21 will be raised and will disconnect the bar 17 from the bar 32, which
will immediately allow the signal to assume the danger attitude under the action
of the counterweight of the bell crank lever 33. The bar 32 will take up its
extreme position to the left, and the pawl 31 will be unable to again come into
engagement with the projection or shoulder 35 until the signal lever shall have
been completely put back to its normal position in which, by the means already
described, it will be automatically locked until released by the operation of a
second lever. On the return of the hinged bar 17* and sliding bar 17 by the action

page_text: of the counterweight 19 when the signal lever is put to the normal position, the
outer end of the slot in the bar 17* will come into contact with the adjacent
end of the weighted lever 42, move it in the direction of the arrow, and withdraw
the locking pin 39 from the intermediate piece 36. The treadle bar 29. will then
rise to its normal or raised position under the action of its counterweight.
Disengaging apparatus of the kind just described may be placed at the signals 1, 3,
6, and 7, indicated in Fig. 18.
Fig. 21 illustrates a modification in which 17 is the sliding bar connected to the
signal lever, and 32 is a double sliding bar (i.e. one constructed with two longitudinal
members with a longitudinal space between them) connected to the signal. The
pawl 31 is pivotted to the bar 32, and an upwardly projecting part 17ª of the bar 17
works between the two members of the double bar 32 whereby it is guided. 23, 23, are
standards; they may be either slotted or constructed of plates which may comprise
two side-frames with a space between them in which are arranged cross-bars with
anti-friction rollers for supporting the sliding bars 17 and 32. The bar 17 is carried
at one end by a radius rod 22 pivotted to a bell crank lever 24 centred at 24*. 19 is
a counterweight which through the lever 19 and rod 19b takes up the slack of the
wire between the sliding bar 17 and the signal lever when the latter is moved to
its normal position. 26 is the connection between the treadle bar (not shown) and
the bell crank lever 24, whereby on the depression of the treadle bar, the sliding
bar 17 is moved down out of engagement with the pawl 31, thus allowing the
signal to resume the danger attitude.
Releasing gear such as above described may also, in some cases, be applied with
advantage where it is desired to use one lever for working several shunting signals,
as, for instance, at large terminal stations, thus avoiding multiplication of levers in
the cabin.
Fig. 22 is a side elevation, and Fig. 23 a plan of such gear adapted for working
two signals by one operating lever at the junction of a branch line with a main
line. 32 and 32ª are two sliding bars connected respectively to the main line and the
branch line signals which, though not shown, may be called A and B. The said bars
are arranged to work in the standards 23, and each is provided with a stop at 35º,
and with a pin at 34 to limit its movement to the left. 17 and 17ª are two sliding
bars jointed together at 44. Their free ends work in guides in the right hand
standard 23; and are connected both to one operating lever, as indicated, by
flexible connections. Each of these sliding bars 17 and 17" is provided with a
shoulder 31 that performs the function of the pawl 31 shown in Figs. 19 and 20.
The bar 17a is connected by a link 45 to one arm of a bell crank lever 46, the
other arm of which is operated by a rod 47 worked by the movement of points.
48 is a weighted bell crank lever pivotted at 48* and connected by a link 49 to
the sliding bar 17*; its tendency is to pull the jointed bars 17 and 17 to the left.
The action of this apparatus is as follows: When the parts are in the relative
positions shown in the drawings, if the signal lever be operated, the shoulder 31*
of the sliding bar 17 being in contact with the stop 35, the sliding bar 32 and
the main line signal (B) in connection therewith will be lowered. Whilst this
is taking place, the other signal (A) will be unaffected because the sliding bars 17
and 32ª are not connected together. If, however, the points at the junction of the
two lines be reversed, their movement will cause the bell crank lever 46 to move in
the direction of the arrow, thereby lowering the connected ends of the bars 17
and 17. This movement will disengage the bar 17ª from the bar 32, and connect
the bar 17 with the bar 32, so that if the signal lever be again operated, the
signal (A) in connection with 32* will be lowered. As will be obvious, apparatus
such as just described may be used for actuating other signals than those for the
main and branch lines just described, where the object is to operate two or more
signals by one lever only.
At a station or passing place we provide a treadle bar or bars in connection
with suitable locking mechanism so applied as to control, by means of the treadle
bar, the whole of the conflicting siguals; the arrangement being such that the

page_text: treadle bar is connected directly with locking mechanism applied to the lever
frame, so as to lock the levers as required, independently of the connections
whereby the levers operate the signals. With such apparatus, assuming, for
example, that in the case hereinabove given by way of illustration, the points
had been closed, the signal lowered for a train to cross over from the down main
line on to the up main line, and afterwards the signal had been returned to the
"danger" attitude and the points again opened, but that the train or vehicle which
should have crossed over remained on the down line, its presence there would
prevent the lowering of the home signal to admit a second train or vehicle onto
the same portion of line.
An arrangement for locking the signal lever or levers by a treadle bar, as
described, is as follows:-When the treadle bar is depressed, it, through suitable.
connections, causes the engagement of a locking lever with the signal operating
lever, the disengagement being automatically effected by a weight or counter-
balance or spring when the treadle bar is released.
An indicator connected to the locking lever shows when the signal lever is
locked.
Fig. 24 shows in end elevation a lever frame and a lever with locking mechanism
controlled by a treadle bar as just referred to. Fig. 25 is a front clevation showing
the lever frame with two levers in position, the positions of five other levers being
indicated by dotted lines.
This
In the Figures we have illustrated the locking of a signal lever by the depression
of a treadle bar by means of a train or vehicle upon it as applied to the locking of
the home signal lever, but it is to be understood that similar locking apparatus
may with advantage be applied to other levers. 55 is a lever pivotted at 55* and
connected at one end to a rod 56. This rod is connected to one arm of a weighted
bell crank lever 57, the other arm of which is connected by a wire 58 or other
suitable connection to a treadle bar which is arranged and operated similarly to
the treadle bar 29 shown in and described with reference to Figs. 19 and 20.
treadle bar is also provided with a locking pin similar to that marked 39 (Figs. 19
and 20) and for a similar purpose. The locking pin is connected to one arm of a
bell crank lever 59 by a wire 60 or other suitable connection. The connection
between the weighted bell crank lever 57 and the treadle bar is such that
when the said bar is depressed by the wheels of a train upon it, the wire 58 is
slackened, the weighted arm of the lever 57 falls and raises the free arm of the
lever 55 so as to bring a shoulder thereon in front of a stop or projection 61 on the
home signal lever 7*. When the treadle bar is depressed it will be locked by
the locking pin herein before mentioned and will remain so locked until the lever
of the starting signal for permitting the train to pass (in the present case the
lever 1 of the starting signal 1) has been pulled over. For this purpose the
lever 1 has connected to it a bar 62 arranged to slide in the lever frame and
carrying a pivotted projection or tappet 63. This tappet is so arranged in relation
to the lever 59 that when it moves in the direction of the arrow with the bar 62
its free end presses against an antifriction roller at the end of the free arm of the
lever 59, raises its other arm which is connected by the wire 60 to the locking pin
and withdraws the latter from the intermediate piece (corresponding to 36 in
Fig. 19) in connection with the treadle bar. This bar is then caused to assume its
highest position by the action of its counter-weight, so pulling the wire 58 and
lowering the free arm of the lever 55 thereby unlocking the lever 7. 64 is an
abutment or stop to prevent the tappet 63 moving on its pivot when operating the
lever 59. When the tappet is moved in the reverse direction with the bar 62 as
when the signal lever 1* pulled over, it turns on its pivot without operating the
lever 59, but its turning movement is limited by a second stop 65. 66 is a stop for
limiting the movement of the free arm of the lever 59 to the left. The free arm of
the lever 55 is notched as shown, so that the signal lever 7 when being returned
is locked by successive stages, thus it cannot be put partly back and then pulled
Over again,

page_text: Assuming treadle bars for locking signals as described to be applied in connection
with the signals indicated at 7 and 6 in Fig. 18, the positions of such bars would
be as there indicated at the sides of the platform lines 53 and 54 respectively.
Additional treadle bars might also be used with advantage in connection with the
starting signals 1 and 3 and the advance starting signal 4 as indicated in dotted
lines for locking the signals 1 and 3 until a train has passed the signal 4. 67 is a
rod connected to the lever 55 and carrying an indicator for showing when the
lever 7a is locked or unlocked.
The operation of this apparatus is as follows:-A train having been admitted to
the platform line 53 by pulling over the home signal 7, the treadle bar there will
be depressed by the train thereby automatically locking the home signal as herein-
above described. The train bar will be held locked in its depressed position by the
locking pin in connection with the lever 59. When the starting signal 1 is pulled
over by operating its lever, the train passes away, and when the said lever is
returned to its norinal position, the locking pin will be withdrawn, releasing the
train bar, and allowing it to rise, thereby causing the locking lever 55 to be
automatically removed from the home signal lever, thus freeing it for further use.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be perforined, we declare that
what we claim is:-
1. The use for automatically locking a lever when returned to its normal
position, of a vertically movable locking bar that descends and engages with a
bar or plate connected to the lever and so locks it, substantially as described.
2. The use in combination for automatically locking a lever and afterwards
unlocking it, of a vertically movable locking bar that descends and engages with a
bar or plate connected to the said lever when it is returned to its normal
position, and so locks it, and a longitudinally movable unlocking bar which by the
operation of a second lever is caused to raise the vertically movable locking bar
out of engagement with the bar or plate connected to the first mentioned lever,
thus unlocking that lever, substantially as described.
3. The combination in a box or frame of vertically movable locking bars for
automatically locking levers when returned to their normal positions, and longi-
tudinally movable interlocking bars for preventing the lowering or showing of
conflicting signals, the said interlocking bars being made to serve also for raising
the vertically movable locking bars to release at the proper times the levers thereby
locked, substantially as described.
4. The use in connection with a semaphore arm or signal of a lever for operating
it, means for automatically locking such lever when returned to its normal position,
and apparatus arranged to be operated by a passing train or vehicle in such a
manner as to cause the return of the signal to the danger attitude.
5.. Apparatus substantially as described with reference respectively to Figs. 19
and 20 and to Fig. 21 of the drawings for the purpose specified.
6. Apparatus substantially as described with reference to Figs. 22 and 23 of the
drawings for the purpose specified.
7. Apparatus substantially as described with reference to Figs. 24 and 25 of the
drawings for the purpose specified.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicants.