IMPROVEMENTS IN APPARATUS FOR OPERATING AND CONTROLLING RAILWAY POINTS AND SIGNALS
Year: 1883

page_text: LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey for an
Invention of "IMPROVEMENTS IN APPARATUS FOR OPERATING AND CONTROLLING
RAILWAY POINTS AND SIGNALS" communicated to him from abroad by Richard
Bianchi, Engineer of Turin, Italy
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office
of the Commissioners of Patents on the 1st November 1883.
"
SYDNEY PITT of Sutton in the County of Surrey IMPROVEMENTS IN
APPARATUS FOR OPERATING AND CONTROLLING RAILWAY POINTS AND SIGNALS
"
[communicated to him from abroad by Richard Bianchi, Engineer of Turin,
Italy]
This apparatus has for its object to satisfy all requirements of the service
necessary to insure the concordant indication of railway signals with the position
of the points or other mechanism placed upon the way which a train obeying the
signals in question will have to run over.
An accumulator is employed; the accumulated force is that of a weight which:
is raised only once for a number of operations and which forces into a principal
conduit T or T a liquid which is not liable to freeze as for example a mixture of
water with glycerine or pure glycerine; this conduit by means of a special
distributor represented in Figure 2 is put in communication with one or other of
the two conduits t'. . which transmit the liquid to each of the mechanisms or
groups of mechanisins which have to be operated in positions relatively invariable..
These two secondary conduits carry the motive liquid to one or other of the
sides of a piston fitted with a rod or into one or other of two cylinders into which
enter two plungers attached to the same rod serving as the prime mover; this rod
which may have a to and fro movement serves to work directly the apparatus for
changing the road, the signals or any other mechanism to which it is connected,
giving two different positions according as the liquid under pressure acts upon one:
or the other of the sides of the piston or upon one or other of the two plungers)
above mentioned.

page_text: When the switch rail requires to be rigidly fixed both in one and in the other of
its two extreme positions or in one only of these positions then this same piston
rod fulfils this condition by operating a special bolt arrangement represented by
Figure 7 which is capable also of being worked by hand when the rod is fixed to
a lever or any other ordinary manual apparatus for operating it.
This mechanism is composed of an axis O which carries two discs R¹ R³ of such
forms that they can be placed underneath the switch rails without interfering with
them when they ought to be moved but so that the rotation to the right or left fixes
one or the other of the two rails against the neighbouring counter rail; at the same
time maintaining the other companion rail properly free from its respective
counter rail
The rotation of the axis O is obtained by means of the draw rod T which is
attached to one end of a bell crank lever mounted upon a pivot and fixed to a
switch rail, the other end of the bell crank being connected by a draw rod to a
crank U on the axis O.
A movement given to the draw rod T to move the switch rails from one to the
other of their two positions has the offect during a first period to rotate the axis
so as to bring the discs beneath the switch rails; in a second period to displace.
the switch rails without turning the axis O, and in a third to again turn the
axis O in the same direction as at first. In short the movement given to the draw
rod T has for its result, 1, to unlock the switch rail. 2. to move it, 3, to lock it
in its new position.
The freedom of the axis O to rotate and consequently of the apparatus for
changing the road may be as it shows by drawing (or it might be, otherwise)
subordinate to that of raising alongside the rail or of approaching to the same
rail a pedal which is unable to move when the wheels of a vehicle are passing it.
The distributor is composed of a cock R moved by a key A by means of the
handle or other instrument attached either permanently or otherwise to one of
its onds.
This cock in one of its positions places the secondary conduit in communication
with the principal T' (or communicating with this principal) and with T2; whilst
when it is in its other position it places t¹ in communication with T and t with T².
One of these conduits serves to conduct the liquid under pressure into the
secondary & the other of the principal conduits serves on the contrary to discharge
the liquid which leaves the secondary.
The handle of the key A is either permitted to move or is locked according as
one or the other of the two teeth m². m². (Figures 2 and 5) attached to the plate P
is engaged or not in a notched cut in the disc C which is fixed on the key (see
Figures 2 and 3).
The plate P is locked in its two extreme positions by a spring stop which enters
into a cavity in the frame of the apparatus (see Figure 1) or by other similar
arrangement. It is worked from the exterior either directly or indirectly. It
completes the course over which it travels in one direction provided that the first
part of this course (corresponding to the displacement of one of the teeth m from
the notch in the disc C) being terminated the axis A is turned carrying a notch
in C to the second tooth.
In short the first movement releases one of the teeth from the notch and allows C
to move; and the second fixes the key A in its new position.
The displacement of the plate P by means of the two other teeth or spurs S¹. S'.
produces by the eccentric button E (Figures 2 and 4) or any like cinematic organ
the rotation of a special grating C Figure 6, which is able in turn to cause a
displacement of the bar S. It can also be prevented from turning on its axis by
blocks placed against the cross bars g. of this grating, or again before or after its
rotation it can be locked by two other bara S, or it can lock in its turn with these
same bars, which are furnished with projections, which operate, or are operated on
by the rotation of similar gratings.

page_text: The control upon the apparatus of a given movement which is produced at a
distance by the rotation of a distributing cock, is obtained by the movement of a
piston S, (Figure 9) of which the rod is furnished with a tooth d. which permits
the rotation in one direction rather than in the other of a sector G attached to a
portion of the locking apparatus which turns or it may be as an alternate
rectilineal movement.
A small pipe b. produced in the cylinder either a compression or rarification of
air; in the first case the piston S is thrust away from the pipe and in the second
on the contrary it is drawn towards it.
The compression and the rarification each correspond to one special and
determinate position on the mechanism which has to be controlled and this
variation of pressure is given by the movement in one direction or the other of the
rod A of a piston, similar for example to that of Smith-Hardy's vacuum brake
(Figure 10).
To ench movement made by this rod the atmospheric pressure is reestablished
by the hole E in the pipe b. and in the two cylinders which are connected together.
The apparatus is not in any way affected by leakage, and the piston S always
indicates a position concordant with that of the rod A Figure 10.
If to the movement of the distributor there does not follow that of the instrument
to be moved (the instrument communicating with the distributor by the secondary
conduits t. 2) it will result that the tooth d. which in consequence of the previous
rotation of the sector G is found between the two teeth d. d. (Above for examplo,
as the Drawing indicates) will prevent the sector accomplishing the second part of
its rotation, and will prevent also the disengagement of the mechanism which
should agree with the mechanism of the distributor, and consequently with that of
the mechanical organ to which it is connected, (switch rails signals etc.) If on the
contrary the movement is exactly accomplished, then S, descends and allows the
sector G to complete the second part of its rotation.
If during the dwell of S, in one of its two extreme positions, the switch rails
signals or other mechanism is displaced; the piston S, also moves, so as to prevent
any rotation of the sector G, because the distributor and the displaced mechanism
are not in the concordant position which the apparatus assigns to them.
When in a set of switch levers or other mechanism having a relatively constant
position such as simple or scissor like connections etc the liberating apparatus for
signals &, it is required to control more than one of these instruments which all
operated by one distributor and its double conduit t. then upon the tube b, a
connection G (Figure 8) is inserted of which the hollow cock R, will be turned in
the same way as the rod A is displaced and put into communication on the one
side with a pipe which goes to the piston S, by means for example, of two
valves V. V, and on the other side of the piston connected with the rod A, by
means of its cavity or vice versa.
It is easy to understand that the hollow cock being so placed that the opening
in it faces the small channel which goes rather to the one than to the other of the
two valves V1, V2. It permits the rarification or compression of the air to be
transmitted from one way or the other, laterally to this same commutator G of the
controlled conduit.
In the apparatus consisting of distributors R, (Figure 2) if in one of them tho
following changes be made.—
1. The opening of the channel C,
2. The filling in of the cavity C³.
3., communicating with the receiver of the liquid under pressure.
4. t¹ communicating with the discharge passage for the liquid, it will result
that;
a. If the cock is in the position indicated in Figure 2 the liquid under pressure
antere hv #2 and communicates with 61

page_text: In the first case the other distributors of the group will receive the liquid under
pressure from t-In the second the movement of the switch rails or other instru-
ments dependant upon the apparatus may be done on the spot, independently of
the apparatus itself; because in the two conduits connecting t¹ and t³, the pressures
are equal, and the liquid expelled on one side of the motive piston of the apparatus
for moving the switch rails is received on the other side, through the relative
distributor. In the third case operations upon the spot, which are very fatiguing
and difficult when the special cock is as in the first case evidently cannot be
produced.
•
The positions 1. 2 and 3 of the distributor in question may at pleasure be
subordinated to variable conditions, by means of the blocks D¹. D³. D³. Figure 6.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Sydney Pitt in the Patent Office on the 1st May 1884.
SYDNEY PITT of Sutton in the County of Surrey. "IMPROVEMENTS IN
APPARATUS FOR OPERATING AND CONTROLLING RAILWAY POINTS AND SIGNALS
"
A communication to me from abroad by Richard Bianchi Engineer of Turin
Italy
This apparatus has for its object to satisfy all requirements of the service necessary
to insure the concordant indication of railway signals with the position of the
points or other mechanism placed upon the way which a train obeying the signals
in question will have to run over.
The apparatus herein described differs from that in actual use, in that it permits
the realization of the following conditions.—
1. The removal of all difficulties due to the distances of the parts to be moved
by the apparatus, by the substitution of accumulated mechanical force (which is
given out in accordance with the requirements) for the muscular force of a man
acting through a rigid or flexible connection; that is to say the removal of all by
mechanical limitations to the range of possible and certain action of the apparatus.
2. The removal of all the difficulties of construction by avoiding the employment
of moving parts to transmit the motive power to the apparatus for altering the
road, or other mechanism which has to be moved.
3. Permitting in certain circumstances of the mechanism for changing the road,
or other mechanism ordinarily connected with the central cabin being made
independent, and consequently capable of being operated by band by ordinary
means by a person on the spot.
4. The automatic working of trailing points by the locomotive or other vehicle
passing over them, and this is without interfering with the operating mechanism
when the changes of the road are not controlled with bolts.
5. A control over the manual apparatus or more correctly over the locking
apparatus which subordinates the manual levers of certain parts of the said
apparatus corresponding to certain changes of the road signals, or other mechanisms
to other parts of the same apparatus corresponding to other instruments and this
is by means of special mechanism which may be adapted also to apparatus of the
ordinary Saxby type, where the movement is produced at the distance by means
of levers, and rigid or flexible connections.
6. The concentration within a small space of all the mechanism necessary for
the working of the apparatus from a central spot as proposed.
The accumulated force is that of a weight, which is raised only once for a
number of operations and which forces into a principle conduit T¹ or T² a liquid
which is not liable to freeze as for example, a mixture of water with glycerine or
pure glycerine; this conduit by means of a special distributer, represented in
Figure 2 is put in communication with one or other of the two conduits t¹ t' which
transmit the liquid to each of the mechanisms or groups of mechanisms which have
to be operated in positions relatively invariable.
These two secondary conduits carry the motive liquid to one or other of the sides
of a piston fitted with a rod, or into one or other of two cylinders into which enter
two plungers attached to the same rod serving as the prime mover; this rod which
may have a to and fro movement serves to work directly the apparatus for
changing the road, the signals, or any other mechanism to which it is connected,
giving two different positions according as the liquid under pressure acts upon one
or the other of the sides of the piston, or upon one or other of the two plungers
above mentioned.

page_text: When the switch rail requires to be rigidly fixed, both in one and in the other
of its two extremo positions or in one only of these positions, then this same
piston rod fulfils this condition, by operating a special bolt arrangement repre-
sented by Figure 7; which is capable also of being worked by hand when the rod
is fixed to a lever, or any other ordinary manual apparatus for operating it.
This mechanism is composed of an axis O which carries two discs R' R' of such
forms that they can be placed underneath the switch rails without interfering
with them when they ought to be moved, but so that the rotation to the right or
left fixes one or the other of the two rails against the neighbouring counter rail, at
the same time maintaining the other companion rail properly free from its
respective counter rail.
The rotation of the axis O is obtained by means of the draw rod T which is
attached to one end of a bell crank lever mounted upon a pivot, and fixed to a
switch rail, the other end of the bell crank being crannected by a draw rod to a
crank upon the axis O.
A movement given to the draw rod T. to move the switch rails from one to the
other of their two positions has the effect during a first period to rotate the axis
so as to bring the discs beneath the switch rails; in a second period to displace
the switch rails without turning the axis O, and in a third to again turn the
axis O in the same direction as at first. In short the movement given to the
draw rod T has for its result. 1 to unlock the switch rail. 2 To move it. 3 to lock
it in its new position.
The freedom of the axis O to rotate and consequently of the apparatus for
changing the road may be, as it shews by drawing (or it might be otherwise)
subordinate to that of raising alongside the rail, or of approaching to the same rail
a pedal, which is unable to move when the wheels of a vehicle are passing it.
The principle organ of this bolt formed by the axis and the two discs may also
be operated, as it has been already stated in unison with the displacement of
switch rails by means of draw bars, of a bell crank fixed to the ground, and a lever,
to the centre of which the draw rod is attached by a joint.
The distributer is composed of a cock R moved by a key A by means of the
handle or other instrument attached either permanently or otherwise to one of
its ends.
This cock in one of its positions places the seconday conduit in communication
with the principle T¹ (or communicating with this principle) and t with T' whilst
when it is in its other position it places t¹ in communication with Tº and t², with T¹.
One of these conduits serves to conduct the liquid under pressure into the
secondary the other of the principle conduits serves on the contrary to discharge
the liquid which leaves the secondaries.
The handle of the key A is either permitted to move or is locked according as
one or the other of the two teeth m¹ m³ (Figures 2 and 5) attached to the plate P
is engaged or not in a notched cut in the disc C, which is fixed on the key (see
Figures 2 and 3).
The plate P is locked in its two extreme positions by a spring stop, which enters
into a cavity in the frame of the apparatus (see Figure 1) or by other similar
arrangement. It is worked from the exterior either directly or indirectly. It
completes the course over which it travels in one direction, provided that the first
part of this course (corresponds to the displacement of one of the teeth m from the
notch in the disc C) being terminated the axis A is turned carrying a notch in C to
the second tooth.
In short the first movement releases one of the teeth from the notch and
allows C to move; and the second fixes the key A in its new position.-The
displacement of the plate P by means of the two other teeth or spurs S¹ S² produces
by the eccentric button E (Figures 2 and 4) or any like cinematic organ, the
rotation of a special grating C Figure 6 which is able in turn to cause a displace-
ment of the bar S. It can also be prevented from turning on its axis by blocks
placed against the cross bars g of this grating, or again before or after its rotation

page_text: it can be locked by two other bars S' or it can lock in its turn with these same
bars which are furnished with projections, which operate or are operated on by the
rotation of similar gratings.
This assemblage of gratings bars and blocks constitutes the locked gear which
subordinates the movements of certain distributers to those which affect other
similar organs, which in their turn correspond to prearranged positions of certain
switch rails signals, and other mechanism as before stated."
This locking apparatus differs from that of Saxby as much in the manner of
giving movement to the gratings as in the form of the grating, which theoretically
may be as broad as the sum of two lateral intervals between the axes of these
same gratings. This locking apparatus permits besides better equalization of
the two periods into which the rotation of the grating may be subdivided without
however failing to satisfy any of the cinematic conditions, which are satisfied by
the original locking apparatus of Saxby. The control upon the apparatus of a
given movement which is produced at a distance by the rotation of a distributing
cock is obtained by the movement of a piston S (Figure 9) of which the rod is
furnished with a tooth d which permits the rotation in one direction rather than
in the other of a sector G attached to a portion of the locking apparatus which
turns (or it may be as an alternate rectilineal movement) the position of S can
also be ascertained easily by a simple visual observation according as the said
piston is found at one or other extremity of its free course.
If the cylinder in which S works is horizontal friction will be sufficient to
maintain the piston in its two extreme positions. If on the contrary it is vertical,
the piston S will be held fixed in the position to which it is brought, in the upper
position by spring and in the lower position by its own weight. A small pipe b
produced in the cylinder either a compression or rarification of air. In the first
case the piston S is thrust away from the pipe, and in the second on the contrary
it is drawn towards it.
'
The compression and the rarification each correspond to one special and
determinate position of the mechanism which has to be controlled, and this
variation of pressure is given by the movement in one direction or the other of the
rod A of a piston similar for example to that of Smith-Hardy's vacuum brake
(Figure 10.)
To each movement made by this rod the atmospheric pressure is re-established
by the hole E in the pipe b and in the two cylinders which are connected together.
The apparatus is not in any way affected by leakage, and the piston S always
indicates a position concordant with that of the rod A Figure 10.
If to the movement of the distributor there does not follow that of the
instrument to be moved (the instrument communicating with the distributer by
the secondary conduits t') it will result that the tooth d which, in consequence
of the previous rotation of the sector G, is found between the two teeth ďď
(above for example, as the drawing indicates) will prevent the sector accomplishing
the second part of its rotation, and will prevent also the disengagement of the
mechanism which should agree with the mechanism of the distributer, and
consequently with that of the mechanical organ to which it is connected (switch
rails signals etc). If on the contrary the movement is exactly accomplished,
then S descends, and allows the sector G to complete the second part of its
rotation.
If during the dwell of S in one of its two extremo positions, the switch rails
signals or other mechanism is displaced; the piston S also moves, so as to prevent
any rotation of the sector G, because the distributor and the displaced mechanism
are not in the concordant position which the apparatus assigns to them.
When for example the apparatus for changing the road is furnished with bolts;
as shewn in Figure 7, a crank connected with O moves the rod A Figure 10 by
means of a button, and slotted head connected to the rod itself, in passing from
the intermediate position of O to the extreme position, but not in passing from one
extremity, towards the other; and this because in the first case a rarification in