IMPROVEMENTS IN TRANSMITTING DISPATCHES, AND IN THE APPARATUS CONNECTED THEREWITH
Year: 1873

page_text: LETTERS PATENT to Arthur Auguste Crespin, of No. 7, Avenuè
Parmentier, Paris, in the Republic of France, Civil Engineer, for
the Invention of "IMPROVEMENTS IN TRANSMITTING DISPATCHES, AND IN
THE APPARATUS CONNECTED THEREWITH."
-Sealed the 14th October 1873, and dated the 21st June 1873.
PROVISIONAL SPECIFICATION
left by the said Arthur Auguste
Crespin at the Office of the Commissioners of Patents, with his
Petition, on the 21st June 1878.
I, ARTHUR AUGUSTE CRESPIN, of No. 7, Avenue Parmentier, Paris,
in the Republic of France, Civil Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN TRANSMITTING DISPATCHES,
IN THE APPARATUS CONNECTED THEREWITH," to be as follows, that is to say:-
.
AND
This Invention relates to transmitting the written directions for
telegraphic dispatches, or the telegrams themselves, by means of
pneumatic tubes, and consists in dividing a long line of tube into short
lengths or parts, and in placing at each point of junction an apparatus
[Price 6d.]

page_text: or relay, receiving and forwarding the dispatches automatically in either
direction.
To carry out my Invention a long line of pneumatic tube is subdivided
into a series of lengths, shorter in proportion as the speed required is
greater.
In the accompanying Drawing Figure 1 is a horizontal section
through the axis of the pneumatic tube; Figure 2 is a vertical_section
through the apparatus on the line s, t, Figure 1; and Figure 3 is a
vertical section on the line v, y, Figure 2.
The carriers conveying the dispatches are passed from one length of
tube to the next by means of an apparatus constructed as follows:-The
tube A enters a chamber placed at the point of separation of two
consecutive lengths of line, and at its extremity (outside this chamber)
is perforated with lateral holes, allowing the compressed air to escape;
it is separated from the next length of tube by a space B of about one-
fifth of an inch, which allows a stopper disc E, Figure 2, moveable on
an axis e to be applied to interrupt or be removed to restore the
communication. The beginning B of the next tube which enters the
apparatus is also perforated with holes C, in order to allow compressed
air to enter from the apparatus into the tube for driving the carrier. A
little further on in the tube is a rod D, which causes a slight obstacle to
the passage of the carrier, which on arriving displaces it and causes the
release of a piston rod a, putting the apparatus in motion,
The parts producing motion are the following:-
First. The stopper disc E carrying a counterweight, which allows it in
falling to raise an equilibrated valve for admitting into the line com-
pressed air contained in a reservoir. This valve is united to a small
carriage F moved by the tail of the stopper disc E by means of a clutch
unhooked or detached by means of a cock H slackening the ascension of
the piston P. This piston rises under the action of the interior pressure,
and when it has arrived at the top of its course it is hooked on to the
top of the carriage, and lowers the valve which stops the admission of
air. The air being cut off the carrier moving in this tube then continues
to advance under the expansion of the air. When it arrives the pressure
escapes in the interior of the relay. The piston causes the carrier to
descend, and the whole of the apparatus returns to its normal position.
The expansion can be determined by the action in a cylinder of air

page_text: coming through small tubes parallel to the line, from the line to the
point where it is desired to commence the expansion, which disengages
Thus, when the
the catch p connecting the valve to the carriage.
carriers enter the apparatus. the compressed air escapes through the
holes A at the end of the first tube out of the relay, and by its impetus
enters the second tube and strikes the small interior rod D, which
disengages the rod of the piston P; then the stopper disc E intercepts
the communication with the preceding tube, while communication is set
up between this second tube, and the compressed air from the reservoir,
the valve S opens, and the compressed air passes into the second tube
through the holes C, and drives the carrier so long as this expansion is
produced. Afterwards the compressed air is cut off, the expansion
begins, and the carrier continues its course by virtue of this expansion
until the next relay is reached, when the same operation is repeated.
A similar apparatus is also placed on the other side of the perforated
tube A for the transmission of dispatches in the other direction.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Arthur Auguste Crespin in the Great Seal Patent
Office on the 13th December 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
CRESPIN, of 7, Avenue Parmentier, Paris, in the Republic of France,
Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of June, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and
the said Arthur Crespin,
successors, give and grant unto me,
Her special licence that 1, the said Arthur Crespin, my executors,
administrators, and assigns, or such others as , the said Arthur
Crespin, my 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

page_text: Invention, for
IMPROVEMENTS IN TRANSMITTING DISPATCHES, AND IN THE
APPARATUS CONNECTED THEREWITH," upon the condition (amongst others)
that I, the said Arthur Crespin, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands
and seals, 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, said Arthur Crespin, do hereby declare
the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in
and by the following statement, reference being had to the Sheet of
Drawing hereunto annexed (that is to say):-
The apparatus which is the object of my Invention relates to the
construction of pneumatic lines, inside of which the speed attained by
the carriers that travel through them is completely independent of the
total length of those lines, I mean by pneumatic lines, tubes, or canals,
where the travelling of the vehicles passing through them is produced
by the motion of air in the interior. This motion is effected either by
a charge of compressed air behind the vehicles or by exhausting the
air in front of them, or again by the simultaneous use of both means.
These lines may be made of pipes of various dimensions or sections,
from a cylindrical pipe a few inches in diameter to a tube of large
dimensions with a circular or other section in which ordinary carriages
can circulate.
The apparatus or apparatuses I propose to use in connection with
the lines are intended to divide them into sections, which are
successively run through by the carriers under the same conditions of
speed as when the line has only the length which separates two
apparatuses, and that without stopping, or a sensible slackening of the
speed of the carriers at the junctions of the sections, that is at the
crossing of the apparatuses. The speed of the pneumatic carriers
increases as the length of the column of air which accompanies them
gets shorter; indeed the mathematical calculation on the existing
relation between the speed of the carriers and the length of the tubes
shows that in tubes of the same section, but of different lengths, the

page_text: The duties to be performed by the apparatuses

page_text: of the apparatus.
1st. A valve or damper E, capable of shutting the line up completely
by entering the slit C, where it rests on an annular india-rubber washer
lining the seat.
2nd. A valve S, introducing at a given moment a strong pressure
of air in the line by putting the line in communication with air
reservoirs close to the relay, where that pressure is constantly
accumulating.
The working of the apparatus consists in lowering the valve or
damper E after the carrier or train of carriers has entered into the
section, and in opening the valve S at the same time, to keep every-
thing in that same state during the time necessary for the train to
travel over the section, and to place everything back in the former
position as soon as the section has been crossed.
To render these movements automatic the following arrangements
have been adopted :-In the middle of the box is a small slide F, which
moves vertically on a bed, and two dovetailed shaped guides. This
little slide is joined by means of a small connecting rod to the handle of
the valve or damper E; it is also connected with the valve of admission S,
but not in a permanent manner, as is the case with the valve or
damper E. The connection is such as to be broken off at a given
moment by the motion of a hook fixed at the end of the piston rod P,
which is pressed against the slide by a spring G. This hook takes on
the top of the slide the place occupied by the hook at the end of the rod
commanding the valve S, and this causes the fall and shutting of that
valve. The piston carries a counterpoise, and is raised in a cylinder by
pressure produced in the interior of the box; this movement would be
extremely quick, especially if the air acting as a counterpressure behind
the piston was free to escape in the atmosphere, but as will be seen
further on, the time employed by the piston in reaching the end of its
stroke is used to regulate the time during which the admission of com-
pressed air to the line takes place. The ascent of the piston in the
cylinder is governed by a graduated tap regulating the counterpressure.
The counterpoise placed upon the piston may be said to be the main
spring of the whole apparatus; it is equal in weight to four times the
counterpoise E placed at the end of the damper or valve, and this

page_text: counterpoise E is itself five times the weight of the valve S. The above
description shows that each time the valve S is left to the free action of
the small slide it will be lifted up by the falling of the counterpoise at
the end of the valve E, which weighs 5, the valve S weighing only 1;
the double operation of shutting the line and placing it in communi-
cation with the air reservoirs is thus effected; if on the contrary the
relay is without pressure, the hook at the end of the rod of the piston P,
which weighs 20, rests upon the small slide F, and evidently keeps it in
its lowest position, and consequently it keeps the valve or damper E in
its highest position, as its counterpoise only weighs a quarter of the
weight of the counterpoise on piston P.. This last position is the position
of the relay waiting for the train; the valve or damper E is opened, the
small slide F is kept at its lowest point by the weight of the piston P,
whose hook at the end of the piston rod has been half disengaged during
the descent by the action of the small inclined plane p', thus leaving
sufficient space in front of it on the top of the small slide E for the
hook of the balance valve S to place itself there. To this small inclined
plane p' is fixed a rod a, which at a given moment can completely
disengage the hook at the end of the rod of piston P from the top of the
small slide. It is this which causes the entrance of the train into the
hox or relay by the shock of the train on the cam D which acts on the
rod a.
The result of this is to immediately shut the line by the falling
of the valve under the action of the counterpoise E, and to open the
valve S which gives the train a fresh impetus. The pressure in the line
and in the box lifts up the piston P in the cylinder, and also the
counterpoise which is over it. The tap regulating the counterpressure
has been disposed so that the time of the upstroke is just the necessary
time for the line to receive the required quantity of air to enable the
train to travel over the section. At the instant the piston. P arrives at
the end of its stroke the hook at the end of the piston rod places itself
on the slide F, and in doing so knocks off the hook of the valve S, and
thus stops the admission of air; it also keeps the line shut as long as it
remains under pressure, but as soon as the pressure diappears, that is,
when the train passes from the section to the following one, the counter-
poise I being no longer kept up by pressure comes down and puts
everything back in the first position so as to be ready to repeat the same
motion when the following train arrives.
During the time a train travels in a section the air enters from the
relay box, with which the tube is in communication by means of a

page_text: large quantity of holes made in that part of the tube which crosses
'through the box. The air in front of the carrier or train of carriers
escapes through a small length of pipe just close to the box, .and this
part of the pipe is also perforated.
From the above explanations and the annexed Drawing it will be easy
to understand the working of the apparatus, the principle of, which is
the regulating of the introduction of air by the motion of a piston in a
cylinder, allowing that the piston rises in the cylinder according to the
same law as the trains travel in the line. This is true when the
irregularities are only produced by the pressure, but it is no longer so
when the irregularities come from outside causes. In that case the
unhooking ought to be effected by a special cylinder communicating
with a pipe parallel to the line at the point where it is desired to begin
the expansion. This may also be done and can be easily understood
without a new sketch.
1
In front of the relay round the escapement of the former section there
is a special appliance which has been made, so that even in case of an
accident causing the stoppage of the working of the relay the train in
motion will not be stopped. This appliance clearly shown in the
Drawing annexed consists in the shutting of the former escapement by a
lever L standing in the line at the entrance of the train into the relay.
That escapement when closed is locked up and it is unlocked by the
arrival of the piston P at the top of the cylinder of the relay, and it then
reopens itself under the action of the spring which is coiled round it.
The advantage derived from this appliance can be readily understood.
The train is taken by the pressure of the former relay through the next
relay and section in case of the failure of a relay. There is a slight loss
of time but entire stoppage is completely avoided.
The function of the relay with air pressure being described it is easy
to see that for the working by exhaustion or vacuum the arrangement
for starting the exhaustion is the only thing to be altered; it can then
be done by an electrical arrangement or by compressed air or water.
The relay is in this case placed at the farthest end of each section
through which the carrier or train of carriers is drawn.
Everything in the interior of the relay is similar and answers to the
above description, except the counterpoise of the piston which will be

page_text: underneath instead of above, the vacuum tending to lift it up by
exhaustion and the readmission of air behind the piston is regulated by
the same tap which is used to regulate the counter pressure in the
former arrangement. The movement of trains both ways in the relay
can be effected without any inconvenience, the small cam D acting fully
only in the first direction and hanging on the contrary without effect in
the inverse way.
The above considerations show that a single line of pneumatic tube can
easily be travelled through both ways, and if it is to be worked so it will
only be required to fit at each junction two relays back to back, but
with their escapement between the two. The carrier or train of carriers
which will travel one way will cross the relay placed at the end of the
section of line just travelled over without any effect, because the
little cam D is loose on the side on which it will be struck, but the train
will act on the cam D in the relay adjoining, and vice versa.
In the whole of the details I have given above I have supposed that
each relay is provided with its own reservoir for compressed air or
vacuum, according to the mode of working chosen; this arrangement
may be carried out in many ways. However, the establishment of new
pneumatic lines on my principle of relays necessitates the erection of
engines working air pumps & in connection with a certain number of
reservoirs with relays. The number of these reservoirs which can be
connected with a set of engines and pumps will increase with the
interval of time. between each carrier or train of carriers sent through.
It is of course readily understood that as these reservoirs are in free.
communication with each other through a special line of pipes, they
have constantly a tendency to be in equilibrium of pressure, and they
always come to that after a certain time. It is sufficient for having a
pneumatic line in good working order to make that time less than the
time between two trains. As an illustration of this if the trains start.
only every fifteen minutes a set of engines and pumps are connected
with five miles of pneumatic tube on each side, or in other words after
the passage of a train which will have exhausted the power of a reservoir
placed at five miles from the engine it will take less than fifteen
minutes to put it up again to its working power. If the trains are more
frequent the engines and pumps must be nearer to each other and be
connected with a smaller length of pipes.
•

page_text: In summing up the description of my pneumatic line with relays I
shall say that it is made up of a series of consecutive lines with the
same axis, and each of them provided with the apparatuses for the
receiving and forwarding, these apparatuses being brought successively
and instantaneously into action when the train presents itself at the
entrance of each line.
As to the working and keeping in order of these apparatuses it will be
done in the manner that will best suit the requirements of each case in
which they are used.
Having described the nature of my Invention and the manner of
performing the same, I declare that what I claim as my Invention to be
protected by the herein-before in part recited Letters Patent is, the
combination, arrangement, and application of relays worked in con-
nection with pneumatic tubes for the transmission of dispatches as
herein-before described.
In witness whereof, I, the said Arthur Crespin, have hereunto
set my hand and seal, this Eleventh day of December, in the
year of our Lord One thousand eight hundred and seventy-
three.