Im- PROVEMENTS IN THE POINTS, CROSSINGS, AND SIGNALS OF RAILWAYS
Year: 1874

page_text: LETTERS PATENT to Robert Burn, junior, and Leopold Joseph Green,
both of Epsom, in the County of Surrey, for the Invention of “Im-
PROVEMENTS IN THE POINTS, CROSSINGS, AND SIGNALS OF RAILWAYS."
PROVISIONAL SPECIFICATION left by the said Robert Burn and
Leopold Joseph Green at the Office of the Commissioners of
Patents, with their Petition, on the 3rd March 1874.
Wo, ROBERT BURN, junior, and LEOPOLD JOSEPH GREEN, both of
Epsom, in the County of Surrey, both do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE POINTS, CROSSINGS, ANd Signals
OF RAILWAYS," to be as follows :—
This Invention relates to improvements in the construction and means
of working and securing the switches or moveable parts of rails at
railway points and crossings, to the provision of audible signals in con-
nection with the visible standard or semaphore signals, and to means of
working the standard signals to definite positions, or of working them
with or without bringing the audible signals into action.

page_text: Our improvements in respect of switches at points and crossings
are of the following kind:-Instead of making the switch or moveablo
part of the rail to slide horizontally we mount it to partly turn or
rock on horizontal pivots or trunnions, the axes of which on the one
side of the rail is parallel to the main line, and on the other side
to the line branching from it. A pair of such switch rails constituting
a set of points are so connected together that when the one on the
one side of the rail is moved on its pivots downwards so as to rest
firmly on chairs or stops provided to receive it and against the main
rail, the other on the opposite side of the rail is canted upwards and
inwards on its pivots, also against stops, so as to present a gap for
the passage of wheel flanges between it and the main rail. Theso.
switches are mado right and left handed of such form in transverso
section that when the switch is down on its stops it presents a surfaco
for the tread of passing wheels level with the head of the rails, and
when it is canted up it presents on its inner flank a surface on which
the flanges of passing wheels can run in case of a train being backed
through the points when they are not properly set for it.
1
"
Switches such as we have described above may be worked and locked
in any known manner. We prefer however to adopt the following
methods, which are also applicable to the working of switches con-
structed in the ordinary manner:When the points are connected
to a locking bar such as is described in the Specification of a Patent
granted to James Livesey and others, on the 27th February 1867,
No. 547, we mount in the space between the rails a lever having
two equal arms which form with each other an obtuse angle somewhat
less than two right angles. To each end of this lever one of the switch
rails is jointed by a connecting rod, and one of the ends or another
arm of the lever is connected by a rod to one arm of a bell crank
worked by the point rod. The same bell crank may be employed
to work the locking bar by means of a toggle joint. When the point
rod is moved the central lever above referred to is caused to rock on
its pivot, whereby the one of its arms and the rod connecting it to
the one switch rail are brought into a straight line with one another
so as to push the one switch rail against the main rail, while the.
other arm of the lever forming an angle with its connecting rod draws
away the other switch rail from the main rail. By bringing the one
arm of the lever and its connecting rod a little beyond their straight

page_text: attitude or dead centre against a stop, the shifting of the switch rails,
except by the movement of the point rod, is effectually prevented. And
in cases where a locking bar is used whereby the point rod itself is
prevented from being moved during the passage of a train, the points
are thus securely locked during such passage.
Another method which we adopt for working and locking the points
is as follows: In the rod or bar connecting the two switch rails wo
provide a recess between two horns, the inner edges of which aro
circular arcs of equal radius, but struck from centres at a distance
apart equal to the travel of the bar. On a pivot between those centres
when the bar is in its middle position we mount a lever, one end
of which is connected to the point rod, and tho other end is formed
with a face rounded to the same radius as that with which the edges
of the horns are struck. On moving the point rod in either direction
out of its middle position (in which position the rounded end of the
lever is in the notch of the bar) the bar is moved and the switches
shifted to either side, and the farther movement of the lever by bringing
its rounded end against the hollow face of the horn on either side
forms a lock for the bar, whereby the points are securely held. When
it is intended to shift the points the first part of the movement of the
point rod and lever by bringing the end of the latter off the horn serves
to unlock the bar; the next part of its movement when the end of the
lever is in the notch serves to move the bar and shift the points, and
the last part of the movement by bringing the lever to bear against the
edge of the other horn locks the bar in its altered position.
.
When a locking bar is employed in connection with points worked
as we have just described, we prefer to connect to such bar by means
of a toggle joint a sliding bolt or stud which can take into notches
formed on the rod connecting the switch rails in such manner that in
effecting the movements above described the said bolt or stud is during
the first part of the motion withdrawn from one of the notches in the
rod, and during the last part of the motion it is brought back into
another notch of the rod, thus locking the rod and the points independently
of the locking effected by the point rod itself.
In order to effect such locking independently of the point rod, and
without the use of the locking bar above referred to, we adopt the
following methods:-Between the two main rails immediately in fronț
▲ 2

page_text: of a set of points we mount parallel to the line of rails a rocking shaft,
from which arms project vertically. This rocking shaft is connected to
the point rod, so that when the points are shifted to either side it is
caused to rock in the one direction or the other. Horizontal bars are
passed through mortices in the chairs supporting the main rails, and are
connected to the arms of the rocking shaft, so that as the latter is caused
to rock, these bars are caused to travel or slide through the said mortices.
The mortices and the bearing of the rails on their chairs are so adjusted
that when a train is passing over these rails they are pressed forcibly
down upon the sliding bars. In such a case, the bars being prevented
from moving by the friction due to the pressure on them, the rocking
shaft to which they are connected is held fast, and thus the point gear
is locked. When however the last wheel of a train has passed these
rails, the pressure on the bars being then relieved, they are free to slide,
and the point gear is therefore released.
Instead of employing a rocking shaft with transverse bars such as wo
have described a sliding bar may be mounted longitudinally under either
or both of the main rails in front of a set of points, the chairs in such
case being morticed or grooved longitudinally under the rails for the
accommodation of the said bar; such sliding bar being connected to the
point gear will be held fast by the pressure of the rails upon it during
the passage of a train, but will be free to slide when the load is off the

page_text: the small opening the counterbalance of the trigger is able to draw back
the piston and at the same time to withdraw the bolt from the point
gear. As the return stroke of the piston can be timed by adjusting the
area of the outlet from the cylinder, the bolting of the point gear can
be sustained during the interval between the passage of one wheel and
the next over the trigger, or for a longer period if desired.
In order to provide the driver of a locomotive with an audible signal
which shall apprise him of his passing a standard signal at danger, in
cases where he may neglect or be unable to see the same, we mount on
the under side of the locomotive or tender a transverse horizontal rocking
shaft, having at each end an arm projecting vertically downwards. On
the same rocking shaft is another arm projecting vertically upwards and.
connected by a cord or chain to the cock of the steam whistle, and also to
a spring so arranged as to draw the arms of the rocking shaft into their
vertical attitude. By the side of the rail we mount a slide or lever or
other obstacle, which can either be raised or moved into such a position
as to catch the arm of the rocking shaft above described when the engine
passes it, or can be shifted out of the range of the said arm. When it is
moved to the former position the downward arm of the rocking shaft of
a passing engine being caught by it and deflected from its vertical
attitude, the upward arm is also deflected, and the cock of the steam
whistle is turned by the pull of the cord or chain so as to cause the
whistle to sound. After passing the slide or lever the spring brings back
the arms of the rocking shaft to their vertical attitude, leaving the
whistle sounding until the driver closes it.
The arrangement of the horizontal shaft with its vertical arms as
above described is such that the whistle is sounded in whichever direction
the engine moves and at whatever side of the rail the deflecting obstacle
may be placed. The obstacle is connected to the signal wire or rod so as
to present itself and be effective on the whistle when the signal stands
at danger, but to be withdrawn from the range of the rocking shaft arm
when the signal is lowered. This construction is applicable not only in
connection with the standard signals, but also to give engine drivers
warning at other parts of the line where an obstacle, such as will act on
the whistle as above described, may be fixed for a temporary alarum.
A convenient form for such removeable and portable obstacle is a bar
bent to a staple or Ụ shape, with a set screw passing through either or

page_text: means of the set screw. One of the projecting limbs acts as tho
obstacle above described, catching the arm of the rocking shaft and
causing the whistle to sound, and these limbs being in duplicate one or
other of them acts on the whistle in whichever way the instrument may
be fixed on the rail.
For working standard semaphore signals from a distance to definite
attitudes such as the three sometimes employed, corresponding respec-
tively to "safety," "caution," and "danger," and also for working such
signals in connection with the audible signalling apparatus just described
in such a manner that the slackness or tightness of the wires shall not
affect the accuracy of the signals given, we arrange the signal levers and
pulls as follows:-On the signal post we mount a bell crank, to one arm
of which we connect the pull wire, the other arm being connected to a
rod carried some distance up the post. Or instead of a bell crank a
pulley may be employed round which the pull wire or a chain attached
thereto is carried and attached to the said rod. The upper end of the
vertical rod is connected to the arm of a lever, which lever has on its
other arm a weight sufficient to counterbalance the semaphore arm and
to give the necessary tension to the pull wire. In the vertical rod below
the said lever is a slot in which works a pin on the arm of a second
lever, and this lever bears against a stop on a third lever in such manner
that it can freely rise, but that when it is depressed it must move the
said third lever, which also is provided with a counterweight, and is pre-
vented by stops from moving beyond a definite range. From the second
of the levers named above a rod is carried up the post to the crank arm
of the semaphore. When the hand lever in the signal box or at a
station at a distance is over or in its normal position, the pull wire being
then slacked out, the weight on the first-mentioned lever on the post
having descended and pulled in the slack of the wire and raised the
slotted rod, has also lifted the second lever from off its stop and thereby
pushed up the rod to the semaphore, thereby setting its arm in its
horizontal attitude at danger. On pulling over the station lever to
about midway of its stroke the weight on the first lever is raised, and is
thus taken off the semaphore which descends by its own weight till it
attains the caution attitude, the second lever descending with it till

page_text: it rests on the stop of the third lever, the slot in the vertical rod
affording sufficient freedom for the movement of the second lever to this
definite position notwithstanding the expansion or contraction of the
pull wire. When the station lever is pulled farther over the end of the
slot in the vertical rod bearing on the pin of the second lever depresses
the latter, which bearing on the stop of the third lever moves it so as to
raise its loaded end. The signal is thus lowered to its safety attitude.
On moving back the distant lever the successivo attitudes of the
semaphore are brought about in reverse order.
"
As the three signals above referred to are seldom employed, the two of
danger" and "caution" being usually considered sufficient, we prefer
to employ the arrangement of levers above described in connection with
the audible signal set forth above in the following manner :—Employing
the movement of the lever in the signal box to its extreme position to
work the semaphore to its "caution" attitude, and its movement to
its middle position to work it to the danger attitude, we apply its
farther movement to what is now considered its normal position to
raise or bring into range the lever or slide which is intended to act as
the obstacle for sounding the whistle of a passing locomotive. Thus, in
cases of fog, when the standard signal may not be seen after moving the
lever to its middle position so as to place the semaphore at "danger,"
the farther movement of the lever while the semaphore still remains at
danger moves the lever or slide by the rail, so as to bring it within
range of the arm on the rocking shaft of the locomotive for causing the
whistle to sound. By this arrangement the semaphore in its ordinary
use can be worked, to "caution" or to "danger" without involving the
sounding of the whistle, but when it is necessary, the farther stroke of
the signal lever after the semaphore has reached the "danger" attitude
serves to bring the audible signal apparatus into action. This effect may
also be produced without the farther movement of the signal lever by
altering the length of the pull wire, that is to say, by increasing tho
length when desired so that the audible signal is brought into operation
when the semaphore signal is raised to danger. And in order that such.
variation of the pull wire may be readily effected, instead of fixing the
end of it to the lever in the signal box we bring a chain from it round a
pair of pullies or attach it to the arm of a bell crank upon the said lever,
so that by letting out or drawing in the loop of the chain by shifting one
of the pullics or by partly turning the bell crank, the length of the pull

page_text: wire from the one point of attachment on the signal lever to the other
point of attachment to the lever on the signal post can be varied at
pleasure.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Burn and Leopold Joseph Green in the
Great Seal Patent Office on the 2nd September 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
BURN, junior, and LEOPOLD JOSEPH GREEN, both of Epsom, in the
County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria,, by Her :
Letters Patent, bearing date the Third day of March, in the year of
our Lord One thousand cight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Robert Burn, junior, and Leopold
Joseph Green, Her special license that we, the said Robert Burn, 1
junior, and Leopold Joseph Green, our exccutors, administrators, and
assigns, or such others as we, the said Robert Burn, junior, and
Leopold Joseph Green, our executors, administrators, and assigns,
should at any time agree with and no others, from time to time, and
at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN THE POINTS, CROSSINGS, AND
SIGNALS OF RAILWAYS," upon the condition (amongst others) that we,
the said Robert Burn, junior, and Leopold Joseph Green, our executors
or administrators, by an instrument in writing under our or their hands
and seals, or the hand and seal of one of us or them, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Burn, junior, on behalf of
myself and the said Leopold Joseph Green, do hereby declare the nature
of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following

page_text: statement thereof, reference being had to the accompanying Sheets of
Drawings, and to the figures and letters marked thereon, that is to say:―
This Invention relates to improvements in the construction and means
of working and securing the switches or moveable parts of rails at rail-
way points and crossings, to the provision of audible signals in connection
with the visible standard or semaphore signals, and to means of working
the standard signals to definite positions, or of working them with or
without bringing the audible signals into action.
Our improvements in respect of switches at points and crossings aro
of the following kind :-Instead of making the switch or moveable part
of the rail to slide horizontally we mount it to partly turn or rock on
horizontal pivots or trunnions, the axis of which on the one side of the
rail is parallel to the main lino, and on the other side of the rail to tho
line branching from it. A pair of such switch rails constituting a set
of points are so connected together that when the one on the one side
of the rail is moved on its pivots downwards so as to rest firmly on
chairs or stops provided to receive it, and against the main rail, the other
on the opposite side of the rail is canted upwards and inwards on its
pivots, also against stops, so as to present a gap for the passage of wheel
flanges between it and the main rail. These switches are made right
and left-handed of such form in transverse section that when the switch
is down on its stops it presents a surface for the tread of passing wheels
level with the head of the rails, and when it is canted up it presents on
its inner flank a surface on which the flanges of passing wheels can run
in case of a train being backed through the points when they are not
properly set for it..
Switches such as we have described above may be worked and locked
in any known manner; we prefer however to adopt the following
methods, which are also applicable to the working of switches con-
structed in the ordinary manner :-When the points are connected to a
locking bar, such as is described in the Specification of a Patent granted
to James Livesey and others on the 27th February 1867, No. 547, wo
mount in the space between the rails a lover having two equal arms,
which form with each other an obtuse angle somewhat less than two
right angles. To cach end of this lever one of the switch rails is jointed
by a connecting rod, and one of the ends or another arm of the lever is
connected by a rod to one arm of a bell crank worked by the point rod.

page_text: The same bell crank may be employed to work the locking bar by means
of a toggle joint. When the point rod is moved the central lever above
referred to is caused to rock on its pivot, whereby the one of its arms
and the rod connecting it to the one switch rail aro brought into a
straight line with one another so as to push the one switch rail against
the main rail, while the other arm of the lever forming an anglo with its
connecting rod draws away the other switch rail from the main rail. By
bringing the one arm of the lever and its connecting rod a little beyond
their straight attitude or dead centre against a stop the shifting of the
switch rails, except by the movement of the point rod, is effectually
prevented; and in cases where a locking bar is used, whereby the point
rod itself is prevented from being moved during the passage of a train,
the points are thus securely locked during such passage.
Another method which we adopt for working and locking the points
is as follows:-In the rod or bar connecting the two switch rails we
provide a recess between two horns, the inner edges of which are circular
arcs of equal radius, but struck from centres at a distance apart equal to
the travel of the bar. On a pivot between those centres when the bar
is in its middle position we mount a lever, one end of which is connected
to the point rod and the other end is formed with a face rounded to the
same radius as that with which the edges of the horns are struck. On
moving the point rod in either direction out of its middle position (in
which position the rounded end of the lever is in the notch of the bar)
the bar is moved and the switches shifted to either side, and the farther
movement of the lever by bringing its rounded end against the hollow
face of the horn on either side forms a lock for the bar, whereby the
points are securely held. When it is intended to shift the points the
first part of the movement of the point rod and lever by bringing the
end of the latter off the horn serves to unlock the bar; the next part of
its movement, when the end of the lever is in the notch, serves to move
the bar and shift the points; and the last part of the movement, by
bringing the lever to bear against the cdge of the other horn, locks the
bar in its altered position.
When a locking bar is employed in connection with points worked as
we have just described we prefer to connect to such bar by means of a:
toggle joint a sliding bolt or stud, which can take into notches formed
on the rod connecting the switch rails in such manner that on effecting
the movements above described the said bolt or stud is during the first

page_text: part of the motion withdrawn from one of the notches in the rod, and
during the last part of the motion it is brought back into another notch
of the rod, thus locking the rod and the points independently of the
locking effected by the point rod itself.
In order to provide the driver of a locomotive with an audible signal
which shall apprise him of his passing a standard signal at danger, in
cases where he may neglect or be unable to see the same, we mount on
the under side of the locomotive or tender a transverse horizontal
rocking shaft having at each end an arm projecting vertically downwards.
On the same rocking shaft is another arm projecting vertically upwards
and connected by a cord or chain to the cock of the steam whistle, and
also to a spring so arranged as to draw the arms of the rocking shaft
into their vertical attitude. By the side of the rail we mount a slide or
lever or other obstacle which can either be raised or moved into such a
position as to catch the arm of the rocking shaft above described when
the engine passes it, or can be shifted out of the range of the said arm.
When it is moved to the former position the downward arm of the
rocking shaft of a passing engine being caught by it and deflected from
its vertical attitudes, the upward arm is also deflected and the cock of
the steam whistle is turned by the pull of the cord or chain so as to
cause the whistle to sound. After passing the slide or lever the spring
brings back the arms of the rocking shaft to their vertical attitude
leaving the whistle sounding until the driver closes it.
The arrangement of the horizontal shaft with its vertical arms as
above described is such that the whistle is sounded in whichever
direction the engine moves and at whatever side of the rail the
deflecting obstacle may be placed. The obstacle is connected to the
signal wire or rod so as to present itself and be effective on the whistlo
when the signal stands at danger, but to be withdrawn from the range
of the rocking shaft arm when the signal is lowered. This construction
is applicable not only in connection with the standard signals but also to
give engine drivers warning at other parts of the line where an obstacle,
such as will act on the whistle as above described, may be fixed for
a temporary alarum. A convenient form for such removeable and
portable obstacle is a bar bent to a staple or U shape with a set screw
passing through either or both of its limbs. One limb of this staplo
being passed under the rail the staple is turned so as to present its
limbs projecting upwards one on each side of the rail and is clamped in

page_text: as the obstacle above described, catching the arm of the rocking shaft
and causing the whistle to sound, and these limbs being in duplicate ono
or other of them acts on the whistle in whichever way the instrument
may be fixed on the rail.
For working standard semaphore signals from a distance to definite
attitudes, such as the three sometimes employed, corresponding re-
spectively to "safety," "caution," and "danger," and also for working
such signals in connection with the audible signalling apparatus just
described, in such a manner that the slackness or tightness of the wires
shall not affect the accuracy of the signals given, we arrange the
signal levers and pulls as follows:-On the signal post we mount a
bell crank, to one arm of which we connect the pull wire, the other arm
being connected to a rod carried some distance up the post; or instead
of a bell crank a pulley may be employed around which the pull wire or
a chain attached thereto is carried and attached to the said rod. The
upper end of the vertical rod is connected to the arm of a lever mounted
on the post, which lever has on its other arm a weight sufficient to
counterbalance the semaphore arm and give the necessary tension to
the pull wire. In the vertical rod below the said lever is a slot in
which works a pin on the arm of a second lever, and this lever bears
against a stop on a third lever in such manner that it can freely risc,
but that when it is depressed it must move the said third lever, which
also is provided with a counterweight and is prevented by stops from
moving beyond a definite range. From the second of the lovers named
above a rod is carried up the post to the crank arm of the semaphore.
When the hand lever in the signal box or at a station at a distance is
over or in its normal position, the pull wire being then slacked out, the
weight on the first-mentioned lever on the post having descended and
pulled in the slack of the wire and raised the slotted rod, has also lifted
the second lever from off its stop and thereby pushed up the rod to the
semaphore, thereby setting its arm in its horizontal attitude at danger.
On pulling over the station lever to about midway of its stroke the weight
on the first lever is raised and is taken off the semaphore which descends
by its own weight till it attains the caution attitude, the second lever
descending with it till it rests on the stop of the third lever, the slot in
the vertical rod affording sufficient freedom for the movement of the
second lever to this definite position notwithstanding the expansion or

page_text: contraction of the pull wires. When the station lever is pulled farther
over the end of the slot in the vertical rod bearing on the pin of the
second lever depresses the latter, which bearing on the stop of the third
lever moves it so as to raise its loaded end. The signal is thus lowered
to its safety attitude. On moving back the distant lever the successive
attitudes of the semaphore are brought about in reverse order.
"
<<
As the three signals above referred to are seldom employed the two of
danger" and "caution" being usually considered sufficient, we prefer
to employ the arrangement of levers above described, in connection with
the audible signal set forth above in the following manner :-Employing
the movement of the lever in the signal box to its extreme position to
work the semaphore to its "caution" attitude, and its movement to its
middle position to work it to its "danger" attitude, we apply its
farther movement to what is now considered its normal position to raiso
or bring into range the lever or slide which is intended to act as the
obstacle for sounding the whistle of a passing locomotive. Thus in
cases of fog when the standard signal may not be seen, after moving the
lever to its middle position so as to placo the semaphore at " danger,"
the farther movement of the lover, while the semaphore still remains at
danger," moves the lever or slide by the rail so as to bring it within rango
of the arm on the rocking shaft of the locomotive for causing the whistle
to sound. By this arrangement the semaphore in its ordinary use can be
worked to "caution" or to "danger" without involving the sounding
of the whistle; but when it is necessary the farther stroke of the signal
lever after the semaphore has reached the danger attitude, serves to
bring the audible signal apparatus into action. This effect may also be
produced without the farther movement of the signal lever by altering
the length of the pull wire, that is to say, by increasing the length when
desired, so that the audible signal is brought into operation when the
semaphore signal is raised to danger. And in order that such variation
of the pull wire may be readily effected instead of fixing the end of it.
to the lever in the signal box we bring a chain from it round a pair of
pullies, or attach it to the arm of a bell crank upon the said lever, so
that by letting out or drawing in a loop of the chain by shifting one of
length of the pull
the pullies or by partly turning the bell crank, the
wire from the one point of attachment on the signal lever to the other
point of attachment to the lever on the signal post can be varied at
pleasure.

page_text: THE
Figure 1, Sheet I., represents a plan, and Figure 2 a transverse section
of a switch or pair of points constructed according to our Invention.
A, A, are portions of the fixed rails at a branch or junction; B, B, áro
the moveable rails or rocking switches, mounted by trunnions b, b, at
cach end of them in bearings formed in chairs a, a. The two rocking
switches B, B, have arms which are connected together, and to the point
rod D by connecting rod C, C; when the point rod D is pulled the
one rocking switch is canted against stops on the chairs a so as to bring
its head in coincidence with the one main rail A, while the other switch
is at the same time canted against stops away from the other main rail
A so as to leave sufficient room for the passage of the wheel flanges.
The trunnions bare mounted at some distance from the rails A so that
the head of the switch rails B when moving in their circular arcs away
from the fixed rails shall at once rise above their level, and thus when a
wheel is upon them the shifting of the points is prevented. We prefer
to make the inner face of the switches B with a concave curvature & so:
that when either is canted away from the main rail the edge of a wheel
flange, in case of backing when the points are wrongly set, may run in
the hollow thus presented, as herein-before described. In cases where
moveable switch rails are employed at crossings, such switch rails may
obviously be constructed and worked as the rocking switches above
described. -
Figure 3, Sheet II., represents à plan of a pair of ordinary points
worked by an obtuse angled lever according to our Invention. A, A,
are portions of the fixed rails, and B, B, aro portions of the switchics
or moveable rails, which may be either of the ordinary kind, as shown
in Fig. 3, or of the kind just described in reference to Figures 1 and 2;
C is the point rod working a bell crank D, one arm of which may be
connected by a rod E, forming with it a toggle joint to a locking bar F
of any known construction. This arm of the bell crank is connected by
rod G to one arm I of an obtuse angled lever H, I, which is mounted
ou a base or framing between the rails. One arm H of this lever is con-
nected by a rod h to one of the switches B and the other arm I is like-
wise connected by a rod i to the other of the switches B, the arm and
rod H, h, as well as the arm and rod I, i, constituting a toggle joint.
The base on which the lever H, I, is mounted is provided with stops K, K,

page_text: to limit the stroke of the lever in either direction, so that it can be moved
only so far in the one way as to bring I, i, a little beyond their straight
position or dead centre, and in like manner when moved in the other
way, to bring H, h, a little beyond their dead centre. When this
apparatus is connected with a locking bar F, as shewn in Figure 3, the
rod G is made with a slot L so that the locking bar shall be partially
moved before the switches themselves begin to be shifted.
Figure 4, Sheet II., represents a plan of apparatus for working
switches having a recessed slide and lever according to our Invention,
Figures 5, 6, and 7 representing portions of the apparatus shewn
seperately for the sake of distinctness. A, A, are portions of the fixed
rails; and B, B, are portions of the switches; C is the point rod con-
nected to a lever D mounted on a base or framing between the rails.
The opposite end E of this lever is rounded, and works in a recess formed
in a sliding piece F, which piece is connected by rods G, G, to the
switches B, B. The recess in the sliding piece F is made with a notch
in its middle, on each side of which is a curved check f, f. When the
point rod C is pulled or pushed the end E of the lever worked by it
acting in the notch of F moves F, and with it the switches B in either
direction, so as to close the one switch or the other. The further travel
of E bringing it along one of the curved cheeks f, makes it act as a
stop or lock to prevent the slide F and the switches B connected thereto
from being moved until the lever D, E, is again shifted. It is obvious
that the curved checks f, f, being respectively struck from the centre
of the lever D, E, when the slide F is in its extreme position in each
direction the further movement of the lever D, E, after shifting tho
points cannot be effected unless the slide F has been moved fully over,
and thus the operator acting on the point rod C is apprised by his
ability to give this further movement of the lever D, E, that the points
are fully homo in either direction, or if he be unable to give the further
movement of the lever D, E, he is informed that the complete move-
ment of the switches is from some cause obstructed. A pin on the arm
E is connected by a rod H to a sliding stop or bolt I, the arm E and rod
II constituting together a toggle joint, so that when the lever D, E, is
moved the stop I is drawn into one of two notches formed in the back
edge of the slide F, thereby constituting an additional lock for the
switch. The stop I may have an arm i connected to a locking bar of
any known construction.

page_text: Figure 8, Sheet III., represents an end view, and Figure 9 part of a
side view of a locomotive provided with apparatus according to our
Invention for giving the engine driver an audible signal. At the lower
part of the locomotive is mounted a horizontal rocking shaft A having
arms a, a, projecting downwards at each end, and an arm 6 connected t
by a cord or chain C passing over guide pulleys (or it might be by-rods
and cranks) to the cock D of the steam whistle. In the course of-theso'
connections is a spring E (for which a counterweight may be substituted)
which brings the arms a to their vertical position. A trigger or inclino
F is mounted at one side of the rail in such a manner that it can either
be brought in the way of one of the arms a while the locomotive passes
it, or can be removed out of the way. In the former case the arm a
being deflected as it passes F partly turns the rocking shaft A and
causes the cock D of the steam whistle to be opened, thereby giving the
driver an audible signal. The trigger or incline F may either be con- 1
nected with the semaphore signal as will hereafter be described, or may
be a portable apparatus, which can be temporarily fixed at any part of
the line to give warning to an engine driver in case of obstruction or
repairs.
Figure 10 represents a transverse section of one of the rails with such
an apparatus temporarily secured upon it, and Figure 11 is a side view
of the same. It consists of staple or U shaped piece G provided with a
clamping screw H fitted to the one limb, and a stud I projecting inwards
from the other limb. This staple can be passed under the rail and
turned into the position shewn in Figure 10, and being clamped in that
position by turning the screw H the top of either of its limbs will serve
as an obstacle to deflect the arm a of a passing locomotive, and thereby
to cause the whistle to sound...
7
Figure 12, Sheet III., represents a side view of a signal post provided
with apparatus according to our Invention for giving three distinct
signals, and combining therewith the means of giving the engine driver
the audible signal. On the signal post is mounted a lever A, counter-
weighted sufficiently to raise the semaphore arm to danger, and to take
up the slack of the pull wire when it is paid out. The shorter arm of
the lever A is connected by a slotted rod B to a lever C mounted loosely
on a pin, on which is also mounted another lever D having a counter-
weight sufficient to maintain the semaphore arm in its middle or caution
attitude, and resting on a stop d. The lever C is connected to the crank

page_text: of the semaphore arm, and rests on a stop on the lover D. The rod B
extended downwards is connected either directly to the pull wire P, as
indicated by the dotted lines, or is connected to one arm of a bell-crank
lever E, the other arm of which has a stud bearing against one side of a
lever F. The end of the lever F is formed with a gab, into which takes
a stud projecting from a slide G. This slide is connected to the pull
wire H, and also to a pull wire I, which is attached to one arm of a bell-
crank lever K. The other arm of this bell crank has a counterweight
sufficient to overbalance the weights on A and D, and to draw up the
slack of the pull H when paid out. The lever K is fixed on a rooking
shaft k, from which projects an arm under a rocking plate or triggor L
mounted by the side of the rail.
When the apparatus for giving an audible signal to the engino driver
is not used, the pull P being drawn in the direction of the arrow marked -
upon it serves to lower the somaphore; but when the audible signal.
apparatus forms a part of. the combination the pull H is moved in the
opposite direction or paid out (as indicated by the arrow on it), for the
purpose of lowering the semaphore, and when it is drawn up it serves to
raise the semaphore, and also to bring the audible signal apparatus into
O action, as we will now describe. When the pull H is fully paid out the
weight on K moving the lever F. to the left moves downwards, the
lever E and rod B thereby raising the weight on A, causing the lever 0.
to bear on its stop on D, and to raise the weight thereon, whereby the
semaphore arm is made to descend to its all right position, that is to say,
to hang in coincidence with the post. A certain pull of the wire H,
drawing the slide G and lever F towards the right, slacks up the rod B,
whereupon the weight on A descends, and also that upon D, and thus
the lever C is raised, and the semaphore arm is also raised to its middlo
or caution position, the amount of its ascent being determined by the
lever D resting on its stop at d. A further pull of H in a similar manner
causes the semaphore arm to be raised to its danger attitude by the
action of the weight on A. At this stage the arm on the rocking shaft k
has reached but has not lifted the trigger L. A still further pull of H,
while it lifts the trigger L, has no further effect on the semaphore, as it
merely pulls the lever F away from the stud upon E. The trigger L
however being thus raised (the semaphore still standing at danger) acts
upon the whistle apparatus of a passing locomotive, so as to give the
audible signal as above described, Should the pull H become accidentally
°
B

page_text: broken the counterweight on K draws the slide G towards the left until
its pin escapes from the gab of the lever, whereupon the semaphore.
being freed from the pull I. is raised to the danger attitude by the
descent of the counterweight on A.
In operating with the apparatus above described it is to be understood
that besides the provision made for allowing for the expansion and
contraction of the wire by means of the slot in the rod B, such further
· provision as may be necessary for the same may be made in any known
L
manner.
Having thus described the nature of our Invention, and in what
manner the same is to be performed, we claim,―
First. The use for the switches and crossings of railways of movcablo
rails mounted so as to rock on horizontal trunnions, substantially as
herein described.
Second. The use for working railway switches of an obtuse angled
lever forming with its connections to the switches toggle joints, sub-
stantially in the manner and for the purpose herein described in reference
to Figure 3 of the accompanying Drawings.
Third. The use for working and locking railway switches of a recessed
slide bar connecting the two switch rails, in combination with a round-
ended lever operating in the recess of the said slide bar, substantially in
the manner herein described in reference to Figures 4 to 7 of the accom-
panying Drawings.
Fourth. The use for giving an audible signal to the driver of a
locomotive of a horizontal rocking shaft mounted on the locomotive, and
having arms acted on as the locomotive passes by triggers or other pro-
jections on either side of the rails, such rocking shaft having also an
arm connected to the cock of the steam whistle, substantially as herein
described.
Fifth. The use for working the audible signal above referred to of a
removeable or portable clip of staple or U form, clamped on the rail and
presenting a double head, so that whichever way it is clamped one or
other of its limbs shall operate, substantially as herein described in
reference to Figures 10 and 11 of the accompanying Drawings.
Sixth. The use for setting a railway semaphore signal in its three
attitudes, of two loaded levers and a stopped lever connected to the signal.

page_text: and to the pull, and operating substantially as herein described in
reference to Figure 12 of the accompanying Drawings.
Seventh. The combination with the signal apparatus referred to in the
preceding claim of trigger apparatus for operating the audible signal
herein-before referred to, substantially as herein described in reference
to Figure 12 of the accompanying Drawings.
Eighth. The method, substantially as herein described, of rendering
the working of an audible signal on a locomotive optional, by making it
depend upon a trigger being raised by a farther movement of the signal
pull after that movement of the said pull which has raised the semaphore
signal to danger.
In witness whereof, I, the said Robert Burn, junior, have here-