Improvements in Working and Controlling Points, Turntables, Crossing Gates, and like Railway Traversers, Appliances.
Year: 1888

page_text: This Specification was, upon the 6th day of June 1891, Amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
Signals,
Improvements in Working and Controlling Points,
Turntables, Crossing Gates, and like Railway
Traversers,
Appliances.
I, JOANNES SERVETTAZ of Savona in the Kingdom of Italy 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:
My invention relates to improvements in apparatus for working railway signals
and switches or points, bolts of turn tables, gates at level crossings and the like,
and consists in arrangements whereby it is rendered impossible for the interlocking-
mechanism between the switches or points or other mechanism and the signals to
release the corresponding signals unless the corresponding points are correctly placed
in the required position. By means of an arrangement hereinafter described the con-
trolling mechanism or bolt which locks the switch rails or points is also caused to act
directly upon the said switch rails.
The dependence of the locking-mechanism upon the positions assumed both by the
working fevers and by the corresponding switch rails or points is obtained by means of
a controlling mechanism which when one movement of the switch is completed and
the switch or point rail accurately placed in position or when the switch rails have
been locked or fixed by the bolts in the required position enables the transmission of
force between the apparatus and the switch to be caused to be followed by a similar
return transmission between the same switch and the apparatus by which it is worked.
This return transmission of force or power is utilised for operating the locking
mechanism of the levers in such a manner as to admit of the working of the corres-
ponding signals only when the position occupied by the switch is in accordance with
that of the corresponding hand lever. The locking mechanism of the hand levers
being thus made directly dependent on the positions actually occupied by the switch
rails instead of being merely dependent on the positions given to the levers themselves
enables the apparatus operating according to this invention to prevent such accidents
as result from the improper working of the signals when the switches or points are

page_text: broken or jammed and which are possible with apparatus constructed according to the
systems usually adopted.
The force or power for operating the mechanism constructed according to my inven-
tion is transmitted by the medium of an incongealable liquid under a pressure equal to
say about fifty atmospheres obtained by means of a suitably loaded piston or plunger
in an accumulator of suitable construction. The liquid employed to transmit the
pressure returns to a tank or reservoir, whence it is pumped back into the
accumulator.
Suitable hand levers are employed to operate distribution apparatus or valves which
distribute the liquid under pressure to chambers or cylinders in which it acts upon
pistons or plungers connected to the points or switches or other mechanism. The move-
ments of the levers are mechanically connected or locked together by a series of
tappets, and connecting rods and movements of the connecting rods operated by the
levers of the switches in connection with the controlling mechanism are rendered
impossible except when the repeating mechanism connected with the switch rails has
been properly moved by the action of a piston operated by a return conduit the
distributing valve of which is automatically operated by the controlling mechanism of
the switches.
And in order that my said Invention may be fully understood 1 shall now proceed more
particularly to describe the same and for that purpose shall refer to the several figures
on the annexed sheets of drawings the same letters of reference indicating correspond-
ing parts in all the figures.
Figure 1 of the accompanying drawings shows the hand lever and parts directly
connected therewith partly in section and figure 2 is a plan of the same.
Figures 3. 4. 5 and 6 show the different positions of the hand lever and mechanism
for repeating or reproducing the movement of the switches.
Figure 7 illustrates a locking table or mechanism for interlocking the levers.
Figure 8 shows the hydrodynamic distributer or valve apparatus in section and the
plunger or piston of the controlling mechanism.
The lever working the switch or point rails is capable of oscillating upon an axis
within a given angle and when the switch is acted on by the controlling mechanism a
fraction only (say about three fourths) of the total stroke of the lever is free and
independent of the response of the mechanism controlling the movements produced
by the lever. The levers are locked together by means of a connecting rod 1 and an
ordinary tappet and plunger locking arrangement as indicated in figure 7. The
angular movement of the lever is communicated to an excentric 2 which moves with
the lever and operates a slide valve in a chamber by means of a connecting rod 3
figures 1. 2 and 8. This chamber receives liquid under pressure through an orifice C
communicating with the accumulator and the valve places an orifice A, communicating
with a pipe not shewn in the drawing in connection either with the accumulator or
with an exhaust or discharge chamber R.
By referring to figures 3. 4. 5 and 6 it will be understood that the hand lever
cannot be rocked to the full extent of its stroke unless a locking plate is displaced.
This plate is operated by a plunger or piston 5 figure 8 acted on by the liquid under
pressure supplied through an orifice B. The said plunger or piston is loaded with a
weight 6 which forces down the plunger or piston when the pressure is removed from
beneath the latter.
The movement of the connecting rod 1 to the full extent of its stroke is permitted
only by the operation of levers which are dependent on the one object that is to be
operated from at a distance by moving the hand lever. The last portion of the stroke
of the hand lever and of the rod is permitted only when the locking plate 4 has been
moved in a certain manner regulated by the mechanism controlling the switch.
Figure 9 sheet 2 is a diagram of the pipes or tubular connections for working
and controlling the action of the apparatus the distributing valves being in their
normal position.
In this figure the pipe supplying liquid for working the switches and locking bolt is
marked A. This pipe is alternately connected either with the accumulator and or

page_text: with the exhaust or with the discharge which latter is its normal position. B. is the
pipe supplying liquid for working the controlling mechanism being in communication
with the pipe A. when the locking bolt is in its normal position and when the bolt
is in the contrary position it is connected with a pipe C. supplying liquid under a
constant pressure of say about 50 atmospheres. This pipe C. may supply any
number of apparatus. D. is a pipe leading to the reservoir or tank at E. receiving
the liquid discharged from the apparatus and G. is a pipe supplying liquid under
pressure from an accumulator at H to a cylinder I containing a plunger I¹ connected
with the locking mechanism of the signals.
The switches and bolts are operated by two pistons or plungers K. K' of different
diameters the area of the piston K. being about half the area of the piston K'. The
pipe A is connected either with the supply pipe C or with the discharge pipe D by
means of a distribution valve L according as the pistons K. K¹ are to be moved to the
left or to the right. The pipe B receives liquid under pressure from the pipe C when
the pipe A is connected with the supply and the movement of the switch to the left
has been completed and checked. M is a distribution valve operated by the locking
bolts or by the switch mechanism when this inochanism has completed the movement
of the switches. On the other hand the pipe B is connected with the discharge through
the pipe A only when the latter is placed in communication with the discharge and the
distribution valve M. has been shifted in consequence of the switches having been
correctly moved over to the right. This distribution valve is provided with a retaining
valve N for the purpose of preventing the liquid under pressure from passing into the
pipe B when the pipe A. is put in communication with the accumulator.
The liquid under pressure supplied by the pipe B may be caused to act upon the
loaded piston or plunger 5 (figure 8) or upon the two coupled plungers K-K' I I'
figure which cause the movements correctly produced by the inotor pistons of the
switches to be repeated in the actuating apparatus.
When two switches-forming a junction for example are worked by one lover and
one pipe such as A which operates the two pairs of motor-pistons of the switches the
distribution valve of the controlling-mechanism of the most distant switch-controls
the pipe B which connects the distribution with the second junction or switch.
The controlling distributor of this switch does not communicate with-the-pipes A
but is provided with two valves N' №2-figure 10 which allow of the passage of the
pressure and of the exhaust in a pipe B' and to the controlling apparatus only when the
positions of the two distributers agree.
Figure 11 represents the working or hand levers and their support in side and end
elevation.
Figure 12 is a front elevation partly in section and figure 13 is a side elevation of
the distributers.
Figure 14 represents the supply pipe communicating with the accumulator and the
pipes leading to the valve chambers of the distribution apparatus.
Figure 15 represents in plan the receiving mechanism placed upon the line for
transmitting motion to the switch rails and working the controlling apparatus.
Figure 16 is drawn to a smaller scale and shews the connection of the apparatus
illustrated in figure 15 with the switch rails. These rails are not provided with
locking bolts but their position is controlled with precision.
Figure 17 shows some details of the parts which prevent the distributer or valve of
the controlling apparatus from acting except when the switch rails have been properly
inoved.
In fig. 15 the pipes marked A B and C correspond with the pipes marked with the
same letters in the diagram fig. 9.
Two pistons or plungers 11 11 figure 15 (corresponding with the pistons KK'
fig. 9.) operate a block or head 2 to which are jointed two connecting rods 3 and 3¹.
The rod 3' is connected with an ordinary safety bar and the rod 3 works a bell
crank lever 4 which acts upon the switch rails by the intervention of a rod 5
figures 15 and 16-The lever 4 oscillates on the extremity of a straight lever 6 which
is pivoted on a support 7. The other extremity of the lever 6 works a sliding plate 8

page_text: provided with a projection 9 figures 15 and 17 which prevents the plate from moving
except when corresponding notches in two sliding bars 10' 10" are placed in a certain
position. The length of the bars 101 1011 is exactly equal to the distance between
the switch rails near the points or thin ends of the latter and these bars are placed
between the said rails at these ends so as to move with the switch rail as it moves
towards the fixed rail being pushed by the opposite switch rail moving from the
corresponding fixed rail.
When the pistons 11 11 move to the left for example they move the lever 6 at first
without acting on the switch rails. The projection 9 on the plate 8 passes through
the corresponding notch in the sliding bar 10' and is stopped by the bar 10". The
movement of the plate 8 being thus arrested the lever 6 is prevented from turning on
its centre. The bell crank lever 4 is then enabled to turn or, oscillate and shifts the
switch rails. When the movement of the latter is arrested the point rail being
correctly pushed home against the fixed rail and the other switch rail having duly
followed its movement the bar 10" is moved in such a manner as to present its notch
in front of the projection 9 on the sliding plate 8 which is then free to continue its
movement to the right. After passing through the notch in the bar 10" the pro-
jection 9 comes in contact with the side of the box or guide and the movement of the
plate 8 is again stopped and this plate presents a point of support for the lever 6 so
as to enable the pistons 1' 1" to exert a considerable pressure upon the switch rails.
By making the stop or projection 9 of sufficient length to enable its end to remain
engaged with the notches in the bar 10' or in the har 1011 a locking motion of the
Napier type will be obtained which mechanically ensures the proper contact between
the switch rail and the fixed rail. If on the contrary the projection does not stop in
the notches in the bar 10¹ a movement of the parts at from the heel of the switch
will be possible without bending or breaking any of the connections and the return
of the switch to its original position will be ensured by the constant action of the
plungers on the bell crank lever 4.
During the concluding period of its stroke the plate 8 operates a distribution
valve 11 (represented by the valve M fig. 9) of the same type as the one in the
apparatus illustrated in Figure 8. This valve 11 supplies the pipe B of the controlling
apparatus. The connecting rod operating the slide is not moved by the plate 8 when
the latter commences its stroke being connected to the said plate by a pin and slot as
indicated in the drawing (Figure 15).
Figure 18 represents in plan an arrangement similar to that illustrated in
Figure 15 combined with a modified locking mechanism which acts directly on
the switch tongues. The locking device operating according to this modification
is represented in elevation and plan in three different positions in Figures 19, 20
and 21, but to this locking device I make no claim.
This locking device worked by a rock shaft 1 supported in bearings attached to
the fixed rails. This shaft is situated underneath the switch tongues and is provided
at or near its extremities with two blocks 21 211 of the shape represented in Figures 19,
20 and 21. The shaft 1 is capable of rotating or rocking within an angle of
90 degrees only and the blocks 21 211 are caused to assume 3 distinct positions.
Figure 19 represents the block 2' inclined at an angle of 45 degrees in which
position it prevents the left hand tongue from coming up to the fixed rail on this side
of the line.
Figure 20 shows the same block in a horizontal position which allows the tongue to
be moved.
Figure 21 shows the block inclined at an angle of 45 degrees from the vertical
being at an angle of 90 degrees from the first position (Figure 19). When in this
third position the block maintains the left hand tongue accurately in contact with the
fixed rail.
A lever similar to the lever 6 Figure 15 acts upon the rock shaft 1 by means
of a connecting rod 2 attached to an arm or lever on the shaft. In this case
a complete stroke of the pistons is likewise divided into three distinct periods as
follows:-

page_text: 1. Rotation or rocking of the shaft to liberate the switch tongues.
2. Displacement of the switch tongues.
3. Final rotation or rocking of the shaft tightening the one tongue against the rail,
maintaining the other separated from the other rail and acting on the mechanism
working the valve of the controlling apparatus.
When this locking mechanism is employed the bars 10', 10" Figure 15 are
dispensed with, and the connecting rod 2 takes the place of the sliding plate 8.
The pistons may be caused to act upon the switch tongues and on an ordinary
safety bar acted on by the flanges of the wheels simultaneously.
The parts may be arranged horizontally as indicated in Figure 15, vertically if
preferred.
In place of the small piston which is constantly exposed to the pressure from the
accumulator a counter-weight may be employed which causes the switch tongues to
return to a normal position automatically whenever the pressure is removed from the
one working piston. In this case the pipe C is dispensed with and the controlling
apparatus allows the pressure to pass from the pipe A to the pipe B provision being
made for and the discharge from B into A by means of a distributer or valve with
two retaining valves as indicated in Figure 10 for controlling a number of junctions
with one pipe
The signals are worked by a single piston which lifts the counter-weight connected
to the signal. This piston may act on the counterweight either directly or through
a wire.
In the latter case it is unnecessary to employ tension apparatus for compensating
the expansion and contraction as the variation in the length of the wire in summer
and winter are compensated for by making the stroke of the piston of sufficient length
to enable the piston to take up the slack at the end of its stroke.
The mechanism for working and controlling the action may be applied by means
of parts such as those hereinbefore described not only to switches and signals but
also to movable stops employed to arrest the motion of vehicles etc. to the locking
bolts of turntables traversing platforms crossing gates and the like or in all cases
where it is required to actuate some object from a distance and to ensure that no
movement not in accordance with the first ease can take place through the absence of
an active control on effected by the movements produced from at a distance.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that I make no
general claim for working railway points, signals and the like at a distance by means of
fluid pressure transmitted through pipes to apparatus connected to the objects moved, but
what I claim is :-
1. The arrangements for operating from a distance and controlling the working of
railway points and signals and other like-mechanism by hydro-danamie transmission
of power-substantially as hereinbefore described.
The arrangements and combinations of parts constituting the improved
apparatus for working and controlling the action of railway points and signals and
other like mechanisin substantially as hereinbefore described with reference to the
accompanying drawings.
Dated this 8th day of May 1888
J. H. JOHNSON & Co.,
Agents.