Improvements in Pneumatic Despatch Tube Apparatus.
Year: 1899

page_text: Date of Application, 27th Dec., 1899-Accepted, 31st Mar., 1900
COMPLETE SPECIFICATION.
Improvements in Pneumatic Despatch Tube Apparatus.
A communication from abroad by the LAMSON CONSOLIDATED STORE SERVICE
COMPANY Incorporated of Lowell, Massachussetts, United States of America.
We, the LAMSON PNEUMATIC TUBE COMPANY, LIMITED, of 20, Cheapside, London,
Manufacturers, do hereby declare the nature of this invention and in what man-
ner the same is to be performed, to be particularly described and ascertained
in and by the following statement:--
This invention relates to improvements in pneumatic despatch tube apparatus
in which the carriers are propelled by air pressure through a single tube in
both directions.
The invention consists of certain novel features hereinafter described and
particularly pointed out.
.
In the accompanying drawings which illustrate a construction embodying the
invention.
Fig. 1 represents in section a terminal at each end of the line with the
connecting pipes between the terminals broken away.
Fig. 2 is a cross sectional view on an enlarged scale showing in rear eleva-
tion parts of the interior mechanism.
To despatch a carrier from the right hand to the left hand end of the line,
it is dropped into the mouth A and passes down the tube B across the valve
box C into the despatch tube D; then the lever E is pulled toward the left as
shown in dotted lines and the arm El of said lever pushes down the valve rod F
against the tension of the spring and opens the valve G 'and allows the
compressed air to flow in through the pipe G¹ and passes by the valve G and
through the narrow passage C' against the rearward extension C2 of the valve C³.
This pressure causes the valve C³ to move to the position shown in dotted lines
closing the tube B so that the air pressure passes down the despatch tube D
and drives the carrier H to the opposite end of the line. The carrier passing up
as shown on the left hand of the figure will pass up through the tube D, valve
box C and tube B and will strike the finger J pivoted at J to the arm J2
pivoted at J3 to the lug J* on the valve casing. As the carrier strikes the
finger said finger moves upwardly and through the medium of the spring K
and link K connected to the main balance arm K² see Fig. 2, the valve C³ is
closed and the carrier after passing out of the tube B enters the left hand
terminal A where it is stopped, the valves C³ being closed, and the left hand
valve G is closed while the right hand valve G is open. Under these conditions
it will be noted that the pressure in the transmitting tube D will rise to the
pressure in the air supply tank A2 to which the pipes G¹ are connected. Said
tank is connected to a suitable air pump by the pipe A³. Communicating with
the pipe D which is below the valve box C at both ends of the line is the pipe L
Jeading to one side of the diaphragm L. Bearing against the outer side of
this diaphragm is the lever L2 pivoted at L3 to the lower end of the lever Lt.
This lever L is pivoted at L5 and extends forwardly in position to engage with
the catch L on the shaft L' upon which the lever E is mounted. By reason

page_text: of this catch L engaging with the upper end of the lever L4 the lever E is held
forwardly to the position shown in dotted lines when pulled forward to despatch
a carrier and in this position holds the valve G open as shown in dotted lines.
The lever L is held in this position by the action of the spring M. In the
apparatus the diaphragm and levers are at one side of the machine and in no
way interfere with the interior mechanism of the valve box.
It will be seen from the above description that when the pressure in the
tube D rises to the pressure of the supply tank A2, that the diaphragm L' is
forced out by the increased pressure and the lever L is forced out of engage-
ment with the catch L allowing the lever E to return to its normal position and
also allowing the spring F¹ to close the valve G shutting off the flow of the air
into the valve box C through the pipe G¹. Upon the insertion of the carrier at
the right hand end of the terminal to be sent to the left hand end or vice versa,
the finger yields downwardly and allows the carrier to pass without affecting
the mechanism. After the air pressure is cut off by the closing of the valve G,.
the air pressure will be relieved from the under side of the valve C3 through a
small hole of about 12 of an inch in diameter formed in the valve and com-
municating with the tube B, thus allowing the valve C3 to open and said valve
is held open by the weight K³ on the hub K+ which is mounted loosely on the
pin K fast in the opposite sides of the valve box C. The hole a above referred
to is of no importance when the valve G is opened as the air pressure is sufficient
to keep the valve C³ closed after a carrier passes it.
When a carrier is to be despatched from the left hand end of the line for
transmission to the right hand terminal, the lever E is moved (as partly shown
in dotted lines) to open the valve G and the spring M acting on the lever L'
will press the latter under the catch L and hold the valve G open. As said
carrier moves up the right hand end of the line it will strike the finger J and
through the connecting mechanism, as previously described, will close the
valve C. When the pressure in the tube D rises to the pressure of the supply
tank A the diaphragm L' at the left hand end of the line will be forced out
and release the lever E and thereby allow the spring F¹ to close the valve G,
thus cutting off the flow of the air from the pipe G into the valve box C. It
will be understood that after a carrier is inserted in the despatch tube and the
valve C3 is closed that another carrier cannot be despatched until the carrier first
despatched has arrived at its destination and the air pressure shut off and the
valve C3 opens as above described. From the above it will be understood that
a carrier cannot be inserted into the despatch tube while a carrier is in transit.
It will be seen that the construction and operation of the mechanisms at
cach end of the line are similar.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
us from our foreign correspondents, we declare that what we claim is:-
1. In a pneumatic despatch tube apparatus, a carrier transmitting tube having
an inlet and an outlet for the carriers, valves for closing said inlet and said
outlet, a source of compressed air, an air inlet for said compressed air to the
transmitting tube, a valve normally closing said air inlet, mechanism for opening
said air inlet valve, mechanism in the path of the travelling carriers adapted to
be operated thereby to close said outlet valve after a carrier has passed said
valve, means for holding said air inlet valve open at the despatch end of the
tube, and means for actuating said air inlet valve holding means for releasing
the same and thereby permitting the closing of said air inlet valve.
2. In a pneumatic despatch tube apparatus, a carrier transmitting tube having
an inlet and an outlet for the carriers, valves for closing said inlet and said
outlet, a source of compressed air, an air inlet for said compressed air to the
transmitting tube, a valve normally closing said air inlet, mechanism for opening

page_text: said air inlet valve, mechanism in the path of the travelling carriers adapted to
be operated thereby to close said outlet valve after a carrier has passed said
valve, means for holding said air inlet valve open at the despatch end of the
tube, and means operated by the pressure on the tube for actuating said air
inlet valve holding means for releasing the same and thereby permitting the
closing of the air inlet valve.
3. In a pneumatic despatch tube apparatus, a carrier transmitting tube having
an inlet and an outlet for the carriers, valves for closing said inlet and said
outlet respectively after the insertion and discharge of the carriers, a source of
compressed air, an air inlet for said compressed air to the transmitting tube, a
valve normally closing said air inlet, a lever for opening said air inlet valve,
mechanism in the path of the travelling carriers adapted to be operated thereby
to close said outlet valve after a carrier has passed said valve, a lever for hold-
ing said air inlet valve open at the despatching end of the tube, a flexible
diaphragm to which said lever is connected on one side and having its opposite
side exposed to the pressure in the tube and adapted when actuated by the
pressure in the tube to operate said lever and thereby release and permit the
closing of said air inlet valve.
4. In a pneumatic despatch tube apparatus, a carrier transmitting tube having
an inlet and an outlet for the carriers, a source of compressed air, an air inlet
for said compressed air to the transmitting tube, a valve located in the path of
the compressed air from the air inlet to the transmitting tube and adapted to
be operated by said air pressure to close the inlet to the transmitting tube, a
valve normally closing said air inlet, mechanism for opening said air inlet valve.
a valve for closing the outlet of the transmitting tube, mechanism in the path
of the travelling carriers adapted to be operated thereby to close said outlet
valve after a carrier has passed said valve, means for holding said air inlet valve
open at the despatch end of the tube, and means for actuating said air inlet
valve holding means for releasing the same and thereby permitting the closing
of said air inlet valve.
5. In a pneumatic despatch tube apparatus, a carrier transmitting tube having
an inlet and an outlet for the carriers, valves for said inlet and outlet, a source
of compressed air, an air inlet for said compressed air to the transmitting tube,
a valve normally closing said air inlet, mechanism for opening said air inlet
valve, mechanism connected to said valves controlling said inlet and outlet and
adapted to allow the insertion of carriers at the inlet end without closing the
valve and to be operated by the travelling carriers at the outlet end of the line
to close the valve controlling said outlet, means for holding said air inlet valve
open at the despatch end of the tube, and means for actuating said air inlet
valve holding means for releasing the same and thereby permitting the closing
of said air inlet valve.
6. In a pneumatic despatch tube apparatus, a carrier transmitting tube having
an inlet and an outlet for the carriers, valves for said outlet and inlet, a source
of compressed air, an air inlet for said compressed air to the transmitting tube.
a valve normally closing said air inlet, mechanism for opening said air inlet
valve, mechanism connected to the valves controlling said carrier inlet and outlet
and adapted to allow the insertion of carriers at the inlet end and to be operated
by the travelling carriers at the outlet end of the line to close the valve con-
trolling said outlet, means for holding said air inlet valve open at the despatch
end of the tube, and means operated by the pressure in the tube for actuating
said air inlet valve holding means, for releasing the same and thereby permitting
the closing of the air inlet valve.
7. In a pneumatic despatch tube apparatus, a carrier transmitting tube having
an inlet and an outlet for the carriers, a source of compressed air, an air inlet
for said compressed air to the transmitting tube, a valve located in the path of
the compressed air from the air inlet, to the transmitting tube and adapted to

page_text: be operated by said air pressure to close the inlet to the transmitting tube, a
valve normally closing said air inlet, mechanism for opening said air inlet valve;
a valve for closing the outlet of the transmitting tube, mechanism in the path
of the travelling carriers adapted to be operated thereby to close said outlet valve
after a carrier has passed said valve, means for holding said air inlet valve
open at the despatch end of the tube, and means operated by the pressure in
the tube for actuating said air inlet valve holding means for releasing the same
and thereby permitting the closing of the air inlet valve.
Dated this 16th day of December 1899.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Chartered Patent Agent, For the Applicants.