IMPROVEMENTS IN RAILWAY SIGNALS
Year: 1884

page_text: COMPLETE SPECIFICATION,
I WALTER CHURCH BECKWITH of Pittsburgh in the County of Allegheny and
State of Pennsylvania, one of the United States of America, Mechanic, do hereby
declare the nature of my Invention for "IMPROVEMENTS IN RAILWAY SIGNALS,"
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 that class of railroad signals which
are actuated by the wheels of an approaching train to give the signal, and by the
departure thereof to withdraw the signal, and it consists in the construction and
combination of parts hereinafter described and claimed, reference being had to
the accompanying Drawing, in which,
Fig. 1 is a longitudinal vertical section, part in elevation representing the
signal and that portion of the operating mechanism immediately connected
therewith.
Fig. 2 is a side elevation of two portions of the same railroad, showing the
operation of my signal mechanism located at the ends of the signal section,
reduced in size and brought near together to show them both in one view.
- Fig. 3 is a detail view of one of the air pumps and its operating mechanism.
A represents a rail of tho road and B a clamp screwed thereto, supporting a
pin c on which the main operating lever C oscillates. Qrepresents the signal
which may be of any style, but for the purpose of this Specification it is shown
as a vane, attached to a horizontal shaft p to oscillate therewith one quarter of a
circle.
.
When the vane Q is horizontal as here delineated, the signal is withdrawn, when
it is set vertical, the signal is given or displayed..
The shaft p enters an air chamber R, and serves as the axis of the piston P,
which is caused to oscillate either by pressure or suction of air through pipes e e¹.
These pipes enter the piston chamber at the, terminus of the piston stroke at
each end of its stroke, but they are each supplied with a branch h and h
respectively, which branches enter the chamber, at points on its side, which points.
are in front of the piston when the piston is at either end.
Each of these branches is supplied with a check valve, which is faced in the
.

page_text: direction to resist the passage of air through it to chamber R, but to allow air to
be freely drawn therefrom, through it by suction in the opposite direction.
Air coming into chamber R, through pipe e', will set the signal, or air drawn
out of the chamber through pipe e will set it, while air pressed in from pipe c, or
air drawn out by pipe el will withdraw the signal.
The pipes e, el connect with air pumps D, D¹ respectively, located on the road
at points from which the signal is to be worked by passing trains, which points
are the ends of the guarded section and there may be two signals, one located near
each pump; in which case one of the pipes, say e would lead to one pump, another
pipe would connect the signal chamber, and a third pipe corresponding to e¹ would
connect the second signal chamber with the other pump.
The pumps are duplicates of each other, or would be if both pumps stood in
the same relation to their operating levers; as shown, the position of valves ff¹
are reversed in the two pumps, but the details are essentially the same, so that the
details of both are shown in Fig. 3.
D represents the cylinder of the pump E, the piston here shown as of bucket
plunger pattern; F is a compression chamber for storing air, when the pump is
worked more rapidly than the air can be pressed along the pipe e, serving to store
the air suddenly received, and give it out gradually through the pipe, f is a check
valve which permits air to pass from the pump into the chamber F but not the
other way. F is an exhaust chamber for the purpose of furnishing to the pump
a large amount of air when the pump is rapidly worked by long express trains;
such quick action of the pump requiring air faster than the friction of a long
pipe c will permit to pass; the vacuum chamber being more leisurely filled by air
drawn from the pipe.
These vacuum and compression chambers serve as equalizers, f¹ is a check valve
which permits air to be drawn through it, into the pump D, but not to go outward
through it.
G is the valve of a fourway cock. It has a rocking motion of one quarter
revolution, when turned one way it connects the vacuum chamber F' as shown in
Fig. 3, with the main pipes and at the same time turns the discharge from
compression chamber F through outlet g into open air, and when valve G is turned
the other way, chamber F is connected with pipe e, and chamber F¹ with outer air.
The piston E is operated by the action of the train wheels upon lever C, every,
wheel that passes, presses the upper arm C¹ of lever Ciḍown, and a spring H raises
it up again immediately after the wheel passes.
Or I may use instead of the spring H an arm shown in dotted lines C¹¹ on the
opposite side of the centre c to be acted on by the wheel to raise arm C³.
The lever C may be connected to the oscillating piston rod-I to operate the
piston directly.
But as it is thought that such connection might work the pump more rapidly
than is required, I have shown one means of reducing the speed of the piston, by
changing its relation to the lever C as follows,
J is a ratchet wheel, provided with a crank i on which the piston rod I is hung,
jis a pawl hung upon the lever C, to engage the teeth of ratchet wheel J so that
the oscillations of lever. C cause wheel J to revolve in one direction, j is a detent
adapted to engage the teeth of wheel J permitting it to revolve freely one way but
preventing any motion of said wheel the other way.
Each revolution of said wheel J and its crank i causes one outward and inward
movement of the piston, thus forcing air into pipe e or either drawing air therefrom,
as the valve G may be set one way or the other.
This valve is actuated as follows,
The central stem of valve G extending outward through the valve chest, is
provided at its outer end with a lever K, which is connected by rod with a loop
shaped lever L which is pivoted at L' to some fixture in the˜rod." l is a latch

page_text: pivoted at to the arm C' of lever C, and at its lower end with a stud M which
plays freely in the loop of the lever L swings said loop to the left, and by means of
rod and lever K sets valve G so that the pump shall act through pipe e on the
signal piston by suction to set the signal and at the same time discharge the air
drawn into the pump at finto the open air through ƒ, F, g.
The same wheel after pressing arm 1 down to the face of arm C³, then presses
said arm C down and operates the pump.
The arm being now pressed down flush with arm C¹ the succeeding wheels
will not operate it, but will operate the lever C to work the pump, so the pump
will continue to work on the signal piston by suction by all wheels coming from
the right.
The operation is as follows,
Fig. 2 shows the guarded. section and all parts of my device in their normal
position of rest, the signals down, and the levers at both ends of the section
ready to receive an impetus to raise it as left by train passing off at the right.
Suppose a train comes on at the right; arm will first be struck by the car
wheel, and be pressed down, swinging lower end of latch to the left, and with it
loop L operating rod k and lever K to twin valve G, so that any action of pump D
will operate by suction to raise the signal Q to danger.
The wheel at the next instant bears down arm causing lever C to so operate
the pump as described.
Suction through pipe e draws air from chamber R through either outlet h or e
and brings over piston P.
When the piston passes the outlet h, the signal is raised, and any further action
of pump D draws air around the piston by pipe h.
This air must be supplied to the chamber by pipe c¹ so that other signals
anywhere thereon may be operated in the same manner as signal Q, and as one
pump acts to set the signal by pressure, while the other acts to set the signal by
suction, the air to supply pipe e' when the pump D is sucking, comes into pump D¹
through its opening g, the same as though valve G were reversed in Fig. 3, and the
air entering at g passes through chamber F through valves f' fand chamber into
the pipe.
Now, when the train, passing off the section, at the left, strikes arm it sets the
valve of pump D₁ to act on the signal by suction thus lowering it.
.
.
If another train now comes on at the right, it finds the first arm already.
depressed, therefor the valve operated thereby is so set that the pump D will again
raise the signal; and in passing off the section the train finds the arm and valve
set so that its action on pump D' again lowers the signal; and so on with any
number of trains coming from the right.
In all cases where trains succeed each other in the same direction, as just stated,
the succeeding train will find the valve G, at the opposite end of the section
entered upon, set to prevent the passage of air in the required direction to permit
piston P to move freely.
Yet the piston will be readily operated upon, since either suction or compression
on one side of the piston meets no similar pressure on the other side, and the
elasticity of the air in the pipe at said other side compensates for the movement of
the piston.
"
When the train ceases to act on the pump at the entering end of the section, it'
leaves the pump valve set against reaction of the air, so that the signal cannot be
returned thereby, but when the train passes off the section, it liberates the pressure
in the pipe by operating the pump at that end of the section.
•
Now, & train coming from the left depresses arm " setting the valve of pump D'
to act by pressure to raise the signal, then in passing off at the right it depresses
that arm to set pump D to operate by pressure to lower the signal and any
number of trains following from the left will find the valves of both pumps ready to
produce the same effect,

page_text: The arms and ", either one being pressed down by the first wheel, will not be
acted on by any wheels from the same direction, and its valve stays set untill the
opposite arm is pressed by an opposite moving train thus changing the valve and
action of the pump.
The clamp B, is secured directly to the rail to support the lever C by its fulcrum
pin c, in a fixed relation to the rail whether the same be pressed down by the
weight of a heavy engine, or in its normal position.
By the use of my Invention the sitting and withdrawing of signals is wholly
automatic.
I do not confine myself to any particular air pumps as it is evident that other
pumps than these shown will accomplish the same result when operated by the
mechanism described.
The characteristic of the operation of piston P is that pressure from pipe e¹ turns
it to the right to set the danger signal, and suction through pipe e does the same
thing, and vice versa, and it makes no difference how the latch 7 stands, a train
approaching from either way will set the signal.
If a train coming from the right were to find the end of 1 of latch Z already
down into its valve would be set right for use, and if the end ¹ were up, the first
wheel would depress it and it would be set right for use, by that same wheel.
This method of actuating the pumps and the signal may be adapted to any style
or system of signaling.
For double track use, when signaling to the rear only is required, a signal may
be placed at each pump and the pumps located, say one mile apart, then the guarded
sections would be one mile long ench.
The pipe connections would be made as described so that in entering each section
the train would set the danger signal for that section, and drop or conceal the signal
one mile to its rear, thus showing a following train what sections are clear and
what occupied.
If used on a single track, the pipes may be arranged to raise danger signals at
each end of the section entered upon.
Or each set of connecting pipes may be allowed to pass the first signal each way
and be connected with the next signal, so that trains may be kept a full section
away from the section 'occupied.
I hereby reserve the right to make application at a future time, for a Patent on a
double ended lever similar to the lever C with the arın C¹ and the arm shown in
dotted lines at C¹¹, said arms being adapted to be pressed down aternately by any
number of wheels in succession coming in either way.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. The combination with the chamber R, the reciprocating piston P, the signal
vane operated thereby, and the main pipes e e¹ entering the chamber at the ends
of the stroke of the piston P, of the branch run-around pipes h h', each provided
with a check valve preventing the passage of air through it into chamber R, but
permitting its passage from said chamber, substantially as specified, whereby air
moving in the main pipes may first operate the piston P, and then pass around it
through chamber R to operate the other pistons and signals as described.
2. A lever pivoted to some fixed object on a railroad, having an arm shaped to be
depressed by trains either way, to actuate a pump, in combination with a two
armed latch pivoted to said lover to project its arms alternatoly beyond the sides of
the lever as described, whereby a passing train will first actuate the latch and
operate the lever and whereby the depressing of either end of latch raises the other
end for purposes specified.
3. The lever arm C' pivoted to some fixed object on a railroad, the latch / pivoted
on said lever and having a stud M in combination with the lever L having a loop
shaped aperture in it, as described, whereby said stud is in the upper part of loop,

page_text: but will not operato same when in lower part thereof, nor when playing vertically
therein, as shown.
4. The latch pivoted to the lever arm C' and having two arms and 1" and a
stud M, in combination with the loop shaped lever L connecting rod k and lever K
as shown and described.
5. The combination with the chamber D of air compression.chamber F, the check
valve fand the four way valve G as shown and described.