Improvements in Railway Signalling and Facing Point Locking Apparatus.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
Improvements in Railway Signalling and Facing Point Locking
Apparatus.
I, WILLIAM GRIFFITHS of 61. Sinclair Road, West Kensington Park, in the County
of Middlesex Civil Engineer do hereby declare the nature of this invention to be as
follows:-
In the Specification of a former application for Letters Patent by myself and
Edward Thomas Roberts Brittain dated 18 December 1886 No. 16,666 is described
an arrangement of apparatus designed to ensure that the points shall be in their
proper positions and to gauge, and that the facing point locking bolt whereby the
points are locked in place shall be completely shot preparatory to the unlocking of
what are known as the detector bolts in connection with the wires or their equivalent
connected to the levers and signals. In that apparatus the switch tongues are
connected by a divided stretcher bar, to one part of which there is pivotted a lever
formed with a slot into which enters a pin or projection carried by the other part of
the divided stretcher bar. To the said lever is connected a locking plate which, when
the points are properly set, and to gauge, occupies a position that leaves the detector
bolt of the corresponding signal free (so far as the said locking plate is concerned) to
move in obedience to the moving over of the signal lever, but should the points not
be correctly placed, or should they froin any cause move apart, or be out of gauge, so
as to cause relative motion of the respective parts of the divided stretcher bar, the
before mentioned lever will be so far actuated that the locking plate connected to it
will be caused to take the position in which the detector will be locked. To ensure
that the facing point locking bolt shall be completely shot before lowering of the
signal, there is applied to an extension of the said locking bolt a projection or device
that operates a bell crank lever of a kind sometimes called-in railway signalling-an
escapement crank or clutch crank, suitably mounted in relation to the said extension
of the bolt, and which has connected to it a locking plate hereinafter called the second
locking plate. The bell crank lever is so formed, and the projection or device on the
extension of the point locking bolt acts in such a way that the said bell crank lever is

page_text: locked in its two extreme positions corresponding to the locking and releasing
positions of the second locking plate, and also that the said bell crank lever and the
locking plate connected to it are moved over from one extreme position to the other
during the travel of the point locking bolt when locking or unlocking the points as
the case may be.
In the arrangement above referred to three locking plates are employed; and my
present invention has for object to simplify the construction, by adapting a single
locking plate, in connexion with the point locking bolt, train bar, and detector bolt or
bolts of a signal, to fulfil the functions of the three locking plates previously employed
as above stated. According to one arrangement for this purpose the slotted lever of
the divided stretcher bar is connected through two pairs of jointed links to a suitable
locking slide the escapement crank has connected to it a connecting rod formed with
a slot that receives an extension of the pin which connects the two links of the one
pair before mentioned; the pin that connects the two links of the other pair enters a
slot in a second rod which is connected to one end of a lever whose other end is
provided with a pin that enters a slot in a rod connected to the train bar. The apparatus
is worked through a lever having suitable connections to the operating lever the point
locking bolt and the train bar. With this arrangement the point locking bolt cannot
be operated whilst there is a train over the train bar and the points must be correctly
set the train bar be worked and the point locking bolt be shot before the corresponding
signal can be lowered.
.
According to a modification one of the pairs of links above referred to may be
dispensed with.
Apparatus with a single locking slide to operate on the principle of my invention
as above set forth may be constructed in various forms.
Dated this 19th day of July 1888

page_text: COMPLETE SPECIFICATION.
'
Improvements in Railway Signalling and Facing Point Locking
Apparatus.
I, WILLIAM GRIFFITHS, of 61, Sinclair Road, West Kensington Park, in the County
of Middlesex, 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
-
In the Specification of a former Patent, granted to me and Edward Thomas Roberts
Brittain, dated 18th of December 1886, No. 16,666, is described an arrangement of
apparatus designed to ensure that the points shall be in their proper positions and to
gauge, and that the facing point locking bolt whereby the points are locked in place
shall be completely shot preparatory to the unlocking of what are known as the
detector bolts in connection with the wires or their equivalent connected to the levers
and signals. In that apparatus the switch tongues are connected by a divided stretcher
bar to one part of which there is pivotted a lever formed with a slot into which enters
a pin or projection carried by the other part of the divided stretcher bar. To the said
lever is connected a locking plate which, when the points are properly set, and to
gauge, occupies a position that leaves the detector bolt of the corresponding signal free
(so far as the said locking plate is concerned) to move in obedience to the moving
over of the signal lever; but should the points not be correctly placed, or should they
from any cause move apart, or be out of gauge, so as to cause relative motion of the
respective parts of the divided stretcher bar, the before mentioned lever will be so far
actuated that a locking plate connected to it will be caused to take the position in
which the detector bolt will be locked. To ensure that the facing point locking bolt
shall be completely shot before lowering of the signal, there is applied to an extension
of the said locking bolt a projection or device that operates a bell crank lever of a kind
sometimes called in railway signalling an escapement crank or clutch crank, suitably
-mounted in relation to the said extension of the bolt, and which has connected to it a
locking plate hereinafter called the second locking plate. The bell crank lever is so
formed and the projection or device on the extension of the point locking bolt acts in
such a way that the said bell crank lever is locked in its two extreme positions corre-
sponding to the locking and releasing positions of the second locking plate, and also
that the said bell crank lever and the locking plate connected to it are moved over from
one extreme position to the other during the travel of the point locking bolt when
locking or unlocking the points as the case may be.
In the arrangement above referred to three locking plates are employed and my
present invention has for object to simplify the construction by adapting a single
-locking plate in connection with the points, locking bolt, train bar (hereinafter called
the facing point locking bar), and detector bolt of a signal to fulfil the functions of
the three.locking plates previously employed as above stated.
According to one arrangement. for this purpose the slotted lever of the divided

page_text: stretcher bar is connected by double jointed links to a suitable locking plate or slide;
the escapement crank has connected to it a connecting rod formed with a slot that
receives an extension of the pin which connects the two links of the one pair before
mentioned; the pin that connects the two links of the other pair enters a slot in a
second rod which is connected to one end of a lever whose other end is provided with
a pin that enters a slot in a rod connected to the facing point locking bar. The
apparatus is worked through a lever having suitable connections to the operating lever,
the point locking bolt and the facing point locking bar. With this arrangement the
point locking bolt cannot be operated whilst there is a train over the facing point
locking bar, and the points must be correctly set, the facing point locking bar be
worked and the point locking bolt be shot before the corresponding signal can be
lowered.
According to a modification one of the pairs of links above referred to may be
dispensed with.
Apparatus with a single locking slide to operate on the principle of my invention
as above set forth may be constructed in various forms.
Referring to the accompanying four sheets of drawings :—
Fig. 1 is a plan or top view, and
Fig. 2 a longitudinal vertical section, of railway signalling and facing point locking
apparatus according to this invention.
Figs. 3 & 4 are respectively a side elevation partly in section, and a plan or top
view of parts of such apparatus, drawn to a larger scale.
Figs. 5, 6 & 7 are end side and plan or top views respectively of one of the guide
brackets or supports shown in Fig. 1.
Fig. 8 is a similar view to Fig. 1 illustrating a modification.
Fig. 9 is a plan or top view of another modification, the cover of the box through
which the plates 31 work, being removed.
Fig. 10 is a side view thereof, the box being in longitudinal section, and the plates
and attached rods in elevation.
Fig. 11 is a side elevation of the box, plates and rods.
In Figs. 1 to 7, 1, 1 are the switch tongues or facing points connected by a divided
stretcher bar and operated when desired by any convenient means as well understood.
2 is a facing point locking bolt arranged to be operated, by a rod 3, double bell
crank lever 4 and rod 5 which is actuated from a lever in the signalman's cabin. 6 is
an extension of the facing, point locking bolt provided with a projection 7 that is so
arranged as to come into contact with one or other of two extensions 8 & 9, formed
on an escapement lever 10, according as the bolt is moved to the left or to the
right.
11 and 12 are the two parts of the divided stretcher bar, each formed with a hole of
different widths at different parts and through one part or other of which the locking
bolt works according to the position of the points. 13 is a slotted lever pivotted to
one part (11) of the stretcher bar. 14 is a pin or projection carried by the other
part (12) and entering the slot 13ª in the lever 13. 15 is a locking plate arranged to
slide through a guide 16 through which slide, at right angles to the plate 15, detector
bolts 17 & 18 that are connected at one end to the signals to be controlled and at the
other end to the signal operating levers. 19 is a facing point locking bar of the
ordinary kind. It is jointed to the double bell crank lever by a rod 20.
The several parts herein before enumerated are similar in construction to the
correspondingly named parts in the said former specification herein referred to.
According to the present invention however, the slotted lever 13 is connected to the
locking plate 15 by two pairs of links 21 and 22 that are jointed to the said lever and
plate as shown. The links 21 are jointed together by a pin 21* and the links 22 by a
pin 22*. 23 is a connecting rod jointed at one end to the lever 10 and formed at its
other end with a-slot 24 through which passes the pin 22*. 25 is a second connecting
rod formed at one end with a slot 26 through which passes the pin. 21*, and connected
at its other end to one arm of a lever 26* the other arm of which carries a pin. 27 that
enters a slot, 28 in a rod 29 connected to the facing point locking bar. 19.

page_text: The action of the apparatus, which is shown in Fig. 1 in its normal position with
the points unlocked, and the signals locked is as follows:-If it he desired to open the
branch line the points are moved over by the usual means provided for that purpose.
The opening of the points for the branch line, causes the lever 13 to move the locking
plate 15 end ways but into a position such as to still lock the detector bolts 17 and 18.
When the points are correctly set they are locked in position by moving the locking
bolt 2 to the left by operating the rod 5 and double bell crank lever 4. This move-
ment of the bolt 2 causes the projection 7 to act upon the extension 8 and force the
lower end of the lever 10, connecting rod 23 and the pin 22* in the slot 24 to the
right and thus cause the links 22, 22 to occupy the position indicated in dotted lines
in Figs. 1 and 4. Motion from the double bell crank lever 4, when shooting the
locking bolt 2, is transmitted through the rod 20 to the facing point locking bar 19,
causing the same to rise and fall in the usual manner, and also through this bar and
the rod 29 and lever 26 to the connecting rod 25 and pin 21* which are moved to
the left causing the links 21, 21 to occupy the positions indicated by dotted lines in
Figs. 1 and 4. The movements of the links 21 and 22 take place simultaneously when the
apparatus is in proper working order, and cause the locking plate 15 to move end ways
through a distance represented by the distance between the lines a b and c d Fig. 4 this
movement being caused by the shortening of the distance between the points of connection
of the links 21 and 22 with the slotted lever 13 and locking plate 15, due to the angular
positions of the said links. The detector bolt 17 will then be released and the
branch line signal connected thereto can be pulled off for the passage of a train or
vehicle, whilst the detector bolt 18 and main line signal connected thereto will
remain locked. Should however the points not be correctly placed and secured or
if they from any cause move apart or be out of gauge so as to cause relative motion
of the respective parts 11 and 12 of the stretcher bar, the slotted lever 13 will be so
far actuated by the pin 14, or this be stationary, by the pivot pin that connects
the said lever to the part 11 that the locking plate 15 will be caused to take a
position in which it will lock both the detector bolts 17 and 18.
If the points should have been correctly placed but the locking bolt 2 not have been shot,
or not have been completely shot, then the links 21 and 22 will not have been moved, or not
have been completely moved as the case may be, into the positions indicated by dotted
lines in Figs. 1 and 4 and consequently the locking plate 15 will continue to lock the
detector bolts in the place. Also, should either of the rods 20 and 29 become broken,
or disconnected from the bar 19 then the links 21 will not be moved into the
angular position and consequently they will prevent the links 22 being so moved by
the action of the locking bolt 2, and will also prevent movement of the locking
plate 15 to unlock either of the detector bolts 17, 18. It will thus be evident that
with the arrangement described the points must be correctly set, the point locking
bolt be completely shot, the facing point locking bar be operated and the several parts
of the apparatus be all intact before the locking plate 15 can be actuated to unlock
either detector bolt and allow of the corresponding signal being pulled off. After
the passage of the train or vehicle on to the branch line, the locking bolt 2 bar 19
and the points are again returned to the position shown in Fig 1 both detector bolts
being then locked in position by the locking plate. To pass a train or vehicle on the
main line, the locking bolt 2 is first completely shot by operating the rod 5 so as to
secure the points in place, and if the apparatus be intact the links 21 and 22 will be
simultaneously moved into their angular positions as before and cause the locking
plate 15 to unlock the detector bolt 18 and main line signal connected therewith, but
still keeping the detector bolt 17 locked. The main line signal is then pulled off for
the train or vehicle to pass, after which the several parts are returned to their original
positions. The slot 28 in the end of the rod 29 permits of the initial movement of
the locking bolt 2 to lock the points, and partial movement of the locking bar 19
before operating the lever 26* and attached parts. 30, 30 are bearings or supports for
the connecting rods 23 and 25 and locking plate 15. In the modified arrangement
shown in Fig. 8, one pair only of jointed links 22 is employed and the connecting
rods 23 and 25 are connected thereto by the joint pin 22* of the links, which passes

page_text: through both of the slotted portions of the connecting rods. The connecting rod 25
is connected with the lever 26* at a point between the pivot of the lever and the
point of attachment thereof with the rod 29 as shown. In other respects the apparatus
is similar in construction to that shown in Figs. 1 to 4 and is marked with the same
reference numerals. With this modified construction it will be readily understood
from the foregoing description that unless the points have been correctly placed and
secured, the links 22 will not be caused to assume the dotted attitude and the locking
plate will consequently not unlock either of the detector bolts. This arrangement of
apparatus is not so desirable as that shown in Figs. 1 to 4 because although the
unlocking movement of the locking plate cannot be obtained until all the several
parts of the apparatus have been properly worked, the movement might take place
notwithstanding a break in connection 20, 23, 25 or 29.
In the arrangement shown in Figs. 9, 10 & 11 there is jointed to each of the con-
necting rods 23 and 25, a slotted plate 31 arranged to slide in a box 32. The slots
which are of corresponding form, are arranged to overlap each other at their adjacent
ends and to incline in opposite directions as shown in Fig. 9, and through the two
passes a pin 33 carried by the locking plate 15 which is arranged to slide through the
box in a direction at right angles to the plates 31. In this arrangement there are no
jointed links and the locking plate is slotted at one end and connected to the slotted
lever 13 by a pin the length of the slot being sufficient to permit of the necessary
travel of the points to set them for the branch line. The movement of the locking
plate to unlock the detector bolts 17 or 18 is effected by the simultaneous movement
of the slides 31 and connecting rods 23 and 25 as will be readily understood from
the foregoing description, but such movement cannot be obtained unless the several
parts of the apparatus have been properly worked and all its parts are intact.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In railway signalling and facing point locking apparatus, a single locking plate
adapted to control a signal or signals and arranged in connection with facing points,
a facing point locking bolt, a facing point locking bar and a detector bolt or bolts for
the signal or signals in such a manner as to be dependent for its unlocking movement,
for releasing the signal or signals, upon the correct setting, gauge, and locking of
the facing points, correct movement of the facing point locking bar, and completion
of the stroke of the facing point locking bolt.
2. In apparatus of the kind herein before referred to, connecting the facing points to
the locking plate by a pair or pairs or double jointed links, and connecting the
escapement lever and facing point locking bar to the said links substantially in the
manner and for the purposes specified.
3. My improved railway signal and facing point locking apparatus constructed
arranged and operated substantially as hereinbefore described with reference to and
shown in Figs. 1 to 4 of the drawings annexed; or modified as described with
reference to Fig. 8 or to Figs. 9, 10 and 11.
Dated this 8th day of Annil 1900