GB2134475A

GB2134475A - Improvements in or relating to pneumatic tube carrier systems

Info

Publication number: GB2134475A
Application number: GB08402392A
Authority: GB
Inventors: Derek Lester Lewis
Original assignee: LAMSON D D Ltd
Current assignee: LAMSON D D Ltd
Priority date: 1983-02-04
Filing date: 1984-01-30
Publication date: 1984-08-15
Also published as: GB8402392D0

Abstract

This invention is concerned with a pneumatic tube carrier system having a pair of stations 1, 2 connected by a pneumatic tube line 3 connecting a local station with a remote station each station having an air supply 9 to supply air to one end of the connecting tube line means operative on insertion of a carrier into one of the stations whereon the air supply of the system is switched on to supply air to move the carrier from the local station to the remote station and pneumatic pressure means to detect changes in pressure at each station whereby its simultaneous insertion of a respective carrier in the two stations is detected and means for switching off one of the air supplies in response to the detection of two carriers in the system at the same time. <IMAGE>

Description

SPECIFICATION Improvements in or relating to pneumatic tube carrier systems This invention has reference to pneumatic tube carrier systems and has particular but not exclusive reference to pneumatic tube carrier systems which are of simple construction and which comprise a pair of stations connected by a length of pneumatic tube and through which a pneumatic tube carrier may be conveyed.

In pneumatic tube carrier systems already known it has been necessary to have a specialist pneumatic tube contractor supply and install for example a pair of stations with pneumatic tube connecting the two stations together with a pump or the like to supply air (under pressure or under vacuum) as well as the electrical and pneumatic control means and control circuits.

It is an object of the present invention to provide an improved pneumatic tube system.

It is a further object of the present invention to provide an improved pneumatic tube system which is capable of being purchased (or rented) and capable of being installed by a resident engineer.

According to the present invention a pneumatic tube carrier system comprises a pair of stations connected by a pneumatic tube line connecting a local station with a remote station, each station having an air supply to supply air to one end of the connecting pneumatic tube line means operative on insertion of a carrier into one of the stations whereon the air supply of the system is switched on to supply air to move the carrier from the local station to the remote station and pneumatic pressure means to detect changes in pressure at each station whereby the simultaneous insertion of a respective carrier in the two stations is detected and means for switching off one of the air supplies in response to the detection of two carriers in the system at the same time.

Preferably the pneumatic tube connecting the two stations is of flexible tubing being capable of being curved to adapt itself to walls or the like in a building.

A pneumatic tube carrier system in accordance with the present invention will now be descried by way of example with reference to the accompanying drawings wherein: Figure 1 is a diagrammatic view of a pneumatic tube system, Figure 2 is a more detailed view of a station, and Figure 3 is a simplified circuit diagram.

As shown in Fig. 1 there is shown a pneumatic tube carrier system having two stations, 1,2 connected by a flexible pneumatic tube line 3 which tube line is preferably of the kind described in our corresponding application for Patent No. 8303197 and which is capable of being connected between stations and of being formed into a bend so that it may be accomodated to fit one inner wall of a building, and around a corner and across another wall of the building or around an obstruction.

The two stations 1 ,2 are of similar construction and each consists of a casing 4 divided into two compartments 5, 6. The first compartment has a inwardly opening door or the like (not shown) for leading a carrier into the tube line 3 or removing a carrier from the compartment 5, and which door is urged closed by pressure air generated in the station when a carrier is to be despatched. The compartment 5 also has a guide 7 against which carriers received from the remote station are moved whereby the carriers are slowed down and halted.The compartments 5,6 are separated by a wall 8 and the compartment has an air supply means preferably a motor blower 9 which serves to supply air under pressure in the tube line 3 and for this purpose a series of appertures 10 are formed in the wall 8 in order that when the air supply means is operative the air pressure in the compartment 5 (and also in the tube line 3) is reduced.

A sensing device 11 is positioned adjacent to the end of the tube line 3 to serve to detect the positioning of a carrier in the end of the tube line 3 when a carrier is first inserted with that end of the tube line 3. A pair of air pressure sensing means 1 2 (Fig. 2) are positioned adjacent to the air supply means to detect changes in air pressure. An electrical control system 1 3 including components and timing circuits are located adjacent to the air supply means to control the movement of the carriers through the tube line 3.

Referring to Fig. 3 of the drawings the electric control system 1 3 includes motor control means and time delay circuits and is connected to the motor blower 9, and to a power input connection. The control system 1 3 is also connected to the sensing device for sensing the location of a carrier in the sending station as well as pressure switches, one to detect high pressure and the other to detect low pressure. The control system is also connected to a warning buzzer to give a warning of malfunctioning of the system, for example if a carrier becomes stuck in the tube line, and to a 'power-on' indicator light as well as a light to indicate that a carrier had arrived at the far station and a push button to reset the system.

The sensing device 11 is connected to a series of time circuits in the control system 1 3 to energise the air supply means at the local station under the control of the timer circuits when a carrier is inserted into the local station whereby air is supplied under pressure to push the carrier from the local station to the remote station. The time circuit is operative to switch off the air supply after a predetermined time, namely after a time taken for a carrier to travel between stations to switch off the air supply at the local (receiving station).

If a carrier is inserted into each one of the stations of the pneumatic tube system at or about the same time the air supply means at each end of the stations will be made operative and having each one of the air supply means driving air into the systems causes the pressure of air to be substantially increased and this increase is detected by the air pressure sensing means 1 2 and this serves to switch off the air supply means in a selected one of the stations which entails that a carrier (or two carriers) is or are each driven to one of the stations.

It will be apparent that a pneumatic tube carrier system as described may be easily installed (or once installed may be readily moved) by a semi-skilled engineer. The stations are located at desired sites and a flexible tube joins the two stations and a simple electric connection is also made to the electric supply. It will be apparent that although there is an electric connection to each station there is no electrical connection between the stations. If desired the system may operate by virtue of air under vacuum. In this case a control button is provided to be operative when a carrier is to be inserted at a local station which switches on a time switch to provide the local air pressure supply means to be switched on and detected at the remote station. The local air supply means is then switched iff by the timer but the remote air supply means is switched on to cause the carrier when inserted into the tube to be conveyed under vacuum to the remote station. On arrival its position is detected by the switch 11 to switch off the air supply means.

Claims

1. A pneumatic tube carrier system comprising a pair of stations connected by a pneumatic tube line connecting a local station with a remote station each station having an air supply to supply air to one end of the connecting pneumatic tube line means operative on insertion of a carrier into one of the stations whereon the air supply of the system is switched on to supply air to move the carrier from the local station to the remote station and pneumatic pressure means to detect changes in pressure at each station whereby the simultaneous insertion of a respective carrier in the two stations is detected and means for switching off one of the air supplies in response to the detection of two carriers at the same time.

2. A pneumatic tube carrier system according to Claim 1 wherein the tube connecting the two stations is of flexible tubing being capable of being curved to adapt itself to walls or the like in a building.

3. A pneumatic tube carrier system according to Claim 1 or 2 wherein the air supply at the local and remote stations each supply air under pressure.

4. A pneumatic tube carrier system according to any one of the preceding claims wherein each station comprises a casing divided into two compartments, one of the compartments housing the air supply and the other one of the compartments having a door for inserting a carrier into the tube line, the compartments being separated by a wall with a series of apertures therein.

5. A pneumatic tube carrier system according to Claim 4 wherein a sensing device is provided adjacent the end of the tube line to sense the location of a carrier in the tube line and which serves to energise the air supply.

6. A pneumatic tube carrier system according to Claim 5 wherein the sensing device is connected on an electrical circuit including a timing circuit.

7. A pneumatic tube carrier system constructed arranged and adapted to operate substantially as herein described with reference to the accompanying drawings.