Year: 1887

page_text: A communication from CHARLES M. JOHNSON, of Chicago, in the County of Cook
and State of Illinois, United States of America, Machinist.
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
M.I.M.E. 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:-
This invention relates to pneumatic dispatch tube systems and it consists in certain
peculiarities of the construction and arrangement of the same substantially as will be
hereinafter more fully set forth.
In order to enable others skilled in the art to which this invention pertains to make
and use the same I will now proceed to describe its construction and operation,
referring to the accompanying drawings in which
Fig. 1 is a diagram view of this system.
Fig. 2 is an enlarged horizontal section of the main and receiving or cushioning
tubes.
Fig. 3 is a somewhat similar view of the arrangement of fan tube cushion and
entrance tube at a station.
Fig. 4 is a vertical longitudinal section of the main tube.
Fig. 5 is a vertical cross section of the entrance and
Fig. 6 an end elevation of the same.
Fig. 7 is a cross section of the tube and one form of carrier and
Fig. 8 is a section of a modified form of carrier.
a represents the main conducting tubes of which there will be one or more as may
be required by the service to be performed. Two are shown in the diagram of

page_text: figure 1, one for the outgoing and the other for the incoming carriers and they will
be constructed of any material or size best adapted to the object in view and beneath,
upon, or above the surface of the ground as desirable this not being of any material
effect in the system I have in view. The tubes will of course be used in stores or
business houses or between one house or place and another house or place, whenever
desired; but the system shall now be shown and described as applied to public service
between cities and the shorter and more easy uses will be readily comprehended
therefrom.
Fig. 1 represents a long line in which are several stations past which the through
carriers are allowed to go but at which any desired carrier may be stopped and
switched out of or removed from the main line according to the destination of the
load it carries.
Each terminal or station is therefore provided with an entrance a to the outgoing
tube, for admitting the carriers and a receiving or cushioning terminal a² for receiving
them as they arrive and each is also provided with an exhaust fan a³ for drawing the
air from the tube and thus forcing the carrier along by the pressure behind it.
In long lines it is evident that a fan placed at one end would not be able to produce
any practical effect from end to end of the tube and the system is therefore divided
into sections and connect a fan with each section and place between the sections a
gate or valve hereinafter described to prevent the fan from exercising any backward
raft on the next section and when a carrier is placed in the tube it is drawn along
till it passes the fan and its momentum then carries it past the division valve (which
opens and closes and opens readily) and it is then at once under the influence of the
next fan and so continues till it reaches its destination. In this way a line of any
length is readily operated and great speed is attained. The tubes or conductors are
constructed air tight, of any desired form, and the carriers are also of various shapes ;
but a cylindrical tube and a carrier formed of a hollow sphere is preferably used and
is illustrated, will be presently described in detail.
61
³ represents an exhaust fan of suitable form connected by a pipe a* with the tube
by which air is exhausted to allow the pressure of air behind the carrier to force it
forward. Each station or terminal is provided with one of these fans which is
connected to the incoming tube; and also with an entrance or supply pipe a' which
connects with the outgoing tube and through which air is supplied as well as the
carriers inserted. Each terminal has its incoming tube provided at its end with a
cushioning cylinder of proper length and of a diameter to closely fit the carrier
when it enters. As clearly seen in figure 2 at stations through which the main line
passes this terminal is provided with a switch or gate operated by a suitable handle
which the attendant can at any time throw across the main tube and thus cut out the
carrier on its arrival and direct it into the cushion where it is stopped by compressing
the air therein as it is passed in and the air thus forms an elastic cushion which stops
the carrier without any jar. Upon one side of this cushion is an exit opening b²
having a gate 63 which is weighted and lies normally across the cushion. The carrier
in passing in readily forces this grate aside and it at once returns to its normal
position so that after stopping the expanding force of the compressed air moving the
carrier backward forces it easily out of the exit and it is thus easily removed from
the tube.
The exit is provided with a hinged cover 6 so that air may not be drawn in at this
point under the influence of the fan.
C
Between the exit opening and the main tube the terminal is also provided with a
gate or valve held normally open by a spring catch e¹ which projects into the path
of the carrier. The latter in its passage strikes the latch and releases the valve which
at once falls and prevents air from passing into the main tube during the removal of
the carrier at the exit as it is not desirable that any air should enter the main line
except at carrier entrance in order that the influence of the fans may always be kept
at their greatest upon this line. This gate e is opened by the attendant after the
carrier is removed.
In some cases it may be found advisable to provide an additional amount of fluid as

page_text: air or gas to the cushion and therefore a pipe d is connected with the end of the
cushioning tube leading to a reservoir of compressed air or gas not necessary to
illustrate herein and in this pipe is a valve d' connected on opposite sides by links d²
to two angle levers d³ hinged in the tube.
When a carrier enters the cylinder it strikes and throws up the first of the lever d³
and opens the valve to permit the fluid to rush in ahead of the carrier. When
sufficient, has been supplied the moving carrier engages the second lever d³ and closes
the valve preventing the admission of more fluid and preventing the escape of that
already admitted by being driven back again into the reservoir.
It will thus be understood that each station on the line is provided with a receiving
cushion and that when desired this cushion may be connected with both the main tubes
so as to act for carriers coming in both directions as in figure 1.
Each end and each station on the main line is also provided with an entrance
connection a which is at its end enlarged to form a chamber e divided from the main
part by a slide valve or cut off e¹ and also a hinged bar e² both of which are connected
to the outside of the chamber as shown.
The outer end is closed by a pivotted door which is swung aside as in figure 6 to
admit the carrier; and the end of the tube is provided with a screw e which bears
against the door and is used to force it open when the exhaustion of the air in the
tube forms a partial vacuum.
By this means when a carrier is to be started the slide valve is closed and the
carrier placed in the chamber and door shut. The valve is then opened and the carrier
is held by the bar e while the air around it is exhausted. The outer door and bar are
then removed and the carrier started with great speed by the impulse of air behind it.
rushing into the tube.
To cut off the air connections between the sections there is provided within the
main line tube, between the fan connections and the next inlet a hinged valve gas in
figure this gate will yield readily to the carrier under its momentum and drop shut
again behind it; but to prevent the too sudden shock of the rapidly moving carrier
which might injure the valve, the latter is connected by a series of levers with an
inclined lever projecting into the path of the carrier. The lower end of this
inclined lever is gradually lifted as the carrier passes under it and thereby opens the
valve which at once falls after the passage of the carrier and prevents the air from
being drawn backward thereby reducing the force applied to drive the ball forward.
When a carrier is started at any point the stations along the line are notified by
telegraph or otherwise of its destination and as in a long line several carriers may be
en route at the same time, they will usually be designated by number and in order
that their passage may be accurately known and the proper one cut off at its
destination the tube is provided with one or more electric conductors either laid
alongside or in a recess or groove of the tube. These conductors are at one or
more points in each section broken and provided with a spring point which is
pressed aside by the carrier and completes the circuit to register in any suitable
manner at the station the end of the section or other convenient points the time of
passing a given point. In this way the carriers may be readily counted their
location known and proper steps taken to cut them out or allow them to pass on as
the case may be.
In figure 7 there is shown a carrier i formed of a hollow ball or sphere having a
cap screwed on as shown. Just below the junction of the cap with the main body is
placed a strengthening cross bar and after being screwed on the cap is locked and
braced by means of a screw rod the head of which is recessed in the outer surface
of the cap and the point screwed into the cross bar as represented. This system of
dividing the long line into a series of connected sections each with its fan and air
supply at opposite ends enables the line to be extended to any distance and maintain
a uniform speed throughout the entire length while the progress of each one is
registered and no mistakes can occur in switching them off the main line.
In figure 8 is shown a carrier formed of papier maché moulded in two parts as m m

page_text: and secured together by metal angle rings m' at the junction of the parts. This forms
a very light and durable carrier well adapted for use in such a system.
Having now particularly described and ascertained the nature of this invention as
communicated to me by my foreign correspondent I declare that what I claim is :-
1. In a pneumatic dispatch system the combination with the main tube of a
receiving and cushioning chamber formed in or connected to said tube and having its
end closed whereby the carrier projected therein is stopped by compressing the air as
it advances substantially as and for the purpose set forth.
2. In a terminal cushion for pneumatic dispatch tubes a cushioning tube provided
with a pipe for supplying compressed air or other fluid and a valve in said pipe to
open or close the same in combination with a hinged lever arm projecting within the
tube and connected to the valve to open it and a second hinged lover connected to
the valve to close it whereby the carrier is caused to automatically open and close the
valve substantially as and for the purpose set forth.
3. The combination with a pneumatic dispatch tube of a cushioning chamber and
means for admitting compressed air or equivalent cushioning fluid therein substantially
as and for the purpose set forth.
a
4. In a terminal cushion for pneumatic tube systems a cushioning tube having
closed end into which the carrier is projected in combination with an exit pipe upon
one side of the cushion and a gate or switch hinged at its junction therewith and
provided with a weight whereby the switch yields readily to the incoming carrier but
cuts off its retreat to the main tube and directs it to the exit substantially as and for
the purpose set forth.
5. A pneumatic dispatch tube divided into a series of independent sections each
provided with an air supply and an exhausting apparatus in combination with a gate
or valve hinged within the tube between the sections and closing firmly in one
direction but opening freely in the other to cut off the passage of air from one section
to the other but admit the easy passage of the carrier substantially as and for the
purpose set forth.
6. A pneumatic dispatch tube divided into a series of independent sections each of
which is provided with an air supply and an exhausting apparatus in combination
with a hinged gate between the sections to cut off the backward flow of air from one
to the other and an inclined arm hinged within the tube and connected to the gate to
open the latter for the passage of the carrier substantially as and for the purpose set
forth.
7. In a pneumatic dispatch system the combination with the tube and its carrier of
an electrical signal circuit connected therewith and broken at intervals and a movable
contact point at said break projecting within the tube whereby the carrier in passing
is carried to close the circuit to signal its progress substantially as and for the purpose
set forth.
8. In a pneumatic dispatch tube the combination with the main tube provided with
an exhaust fan at one end and an entrance chamber at the other of a stop or valve for
retaining the carrier in the chamber while the air is being exhausted and a cover or
door over the entrance whereby the carrier is projected by a sudden rush of air upon
the opening of the door substantially as and for the purpose set forth.
9. The combination with the entrance end of a pneumatic dispatch tube of a door
pivotted over the end of same and a screw or equivalent device for forcing this door
open after the air is rarefied in the tube substantially as and for the purpose set forth.
10. The combination with a pneumatic dispatch tube provided with an enlarged
entrance chamber having a door on its end of a valve for cutting off the chamber from
the tube and a movable stop bar for retaining the carrier after the valve is opened
substantially as and for the purpose set forth.
11. The combination with the main line of a pneumatic dispatch tube and a
cushioning tube connected therewith and provided with an exit on one side of a
hinged vaive normally open arranged in said cushion between the exit and the main

page_text: line and a spring latch for holding this valve open projecting into the tube to be
automatically tripped by the carrier substantially as and for the purpose set forth.
12. A carrier for pneumatic dispatch tubes consisting of a hollow sphere having its
cap secured thereon by a screw rod the head of which is recessed in the cap and the
point screwed into a cross bar within the main body of the carrier substantially as and
for the purpose set forth.
13. The herein described carrier for pneumatic dispatch tubes consisting of the main
body or shell of spherical shape the cap screwed thereon and provided with the
locking rod and the brace across the body below the cap to receive the locking
rod substantially as shown and described.
14. A spherical carrier for pneumatic dispatch tubes formed of papier maché
substantially as described.
15. A carrier for pneumatic dispatch tubes formed of papier maché in two parts
secured together by metallic flanges bolted together and provided with a man hole
upon one side substantially as shown and described.
Dated this 25th day of Ontahan 1007
W. P. THOMPSON & BOULT,
Agents.