PNEUMATIC CONVEYOR DISPATCHER

Abstract: An air-tube conveyor comprising a sending station (12) at which a carrier (14) enters the conveyor, and, an elongate conveyor tube (11) extending from the sending station and along which the carrier is conveyed in use, a tube region within the sending station having an elongate gap (21) in the wall thereof corresponding in length to the length of the carrier, the sending station having inlet means spaced laterally from the axis of said tube region for the introduction of a carrier, and, the sending station being arranged to convey a carrier introduced at said inlet, laterally with respect to said tube region axis, to introduce the carrier in an orientation substantially parallel to said tube region axis through said gap into said tube region.

Description: PNEUMATIC CONVEYOR DISPATCHER Technical Field This invention relates to conveyors of the kind wherein an elongate hollow carrier is transported between a sending station and a receiving station, along a hollow tube joining the stations, by a flow of air within the tube. Conveyors of the kind defined above are often known as air-tube conveyors and are well known. A consideration which is recognised in air-tube conveyor design is the minimum bend radius which is acceptable in the tube. Clearly if the tube bend radius is too tight the carrier will jam at the bend and if the radius is too large there may be wastage of tube material, and difficulty in accommodating the tubework within a building construction. Background Art In a conventional air-tube conveyor system where a sending station is adjacent a working position, such as a supermarket check-out desk, it is convenient to be able manually to insert carriers axially into what is effectively an open end of the tube. Where the main tube run leaving the working position is accommodated below floor level it will be recognised that a bend must be provided in the tube between a vertical, or substantially vertical tube section leading downwardly from the sending station and the tube run extending beneath floor level. Given the minimum bend radius requirement either a significant proportion of the bend must extend above floor level, or, the main tube run must be set sufficiently deeply below floor level to accommodate the bend of the tube within the floor structure. Aesthetic; safety; and space utilisation constraints normally dictate the deep burial option even though it is more costly to provide, in a floor structure, a sufficiently deep trench to instal the tube run. There are however occasions when it is impossible to provide a trench of the necessary depth. It is an object of the present invention to provide an air-tube conveyor wherein this problem is obviated. While the conveyor to be disclosed herein overcomes the aforemention problems its use is not restricted to those environments where deep burial of the main tube run is impossible, and it may find advantage in many other air-tube conveyor installation environments. Disclosure of Invention. In accordance with the present invention there is provided an air-tube conveyor comprising a sending station at which a carrier enters the conveyor, and, an elongate conveyor tube extending from the sending station and along which the carrier is conveyed in use, a tube region within the sending station having an elongate gap in the wall thereof corresponding in length to the length of the carrier, the sending station having inlet means spaced laterally from the axis of said tube region for the introduction of a carrier, and, the sending station being arranged to convey a carrier introduced at said inlet, laterally with respect to said tube region axis, to introduce the carrier in an orientation substantially parallel to said tube region axis through said gap into said tube region. It must be recognised that in the sending station said tube region may be defined by part of the sending station structure; a separate tube component; or, part of the tube component which extends from the station for conveying the carrier may also extend in the opposite direction into the sending station to define therein said tube region. Desirably said sending station has a movable receiver for carrying the carrier into said tube region. Conveniently said receiver is movable bodily, vertically in use, to carry the carrier into said tube region. Alternatively said receiver is pivoted so as to carry said carrier through an arc from an inlet position at an angle to the axis of said tube region to enter said tube region parallel to the axis thereof. Preferably said sending station includes guide means extending at right angles to said tube region between the inlet location of the sending station and said tube region, said guide means being arranged to guide a carrier for movement between the inlet location and the tube region with the longitudinal axis of the carrier parallel to the axis of said tube region. Desirably said guide means guides the carrier for movement under gravity. Preferably said gap in the wall of said tube region is substantially equal in length to the carrier length and at the upstream end of the gap in relation to the direction of movement of the carrier along the tube, there is provided a deflector engaged by the trailing end of the carrier as the carrier passes through the gap, the deflector ensuring that the leading end of the carrier enters the tube region, and the deflector simultaneously imparting longitudinal movement to the carrier so that as the carrier passes through the gap it is moved lengthwise of the tube region. Conveniently the conveyor includes means for sealing the tube region against inlet of air from the sending station when the sending station is not active in the conveying of a carrier. Preferably the sending station includes a carrier receiver for receiving a carrier with its axis parallel to and spaced from the axis of said tube region, and means for rotating the receiver about its longitudinal axis to release said carrier for movement laterally of said tube region through the gap thereof. Preferably said receiver is mounted in a cabinet spaced from said tube region and seats, in a rest position, against seal means to seal the cabinet to prevent flow of air into said tube region by way of the cabinet, there being drive means for moving said receiver dispense a carrier placed in the receiver, through the tube region gap, and said drive means, when operative, displacing the receiver away from said seal means prior to rotating the receiver to dispense the carrier. Brief Description of Drawings Figure 1 is a diagrammatic perspective view of an air- tube conveyor in accordance with a first example of the invention, Figure 2 is an enlarged diagrammatic representation of the sending station of Figure i, Figure 3 is a diagrammatic perspective view of an alternative sending station, Figure 4 is a view similar to Figure 2 of a still further alternative sending station, Figure 5 is an end elevational view of the station seen in Figure 6, Figures 6 and 7 are diagrammatic side elevational views in the open and closed positions respectively, of a further alternative sending station, Figures 8 and 9 are diagrammatic side and plan views respectively of a still further alternative sending station, and, Figures 10 and 11 are diagrammatic perspective and sectional views respectively of modified version of the sending station illustrated in Figure 3. Modes for Carrying Out the Invention Referring first to Figures 1 and 2 of the accompanying drawings the air-tube conveyor comprises a hollow conveying tube 11 formed from synthetic resin material and interconnecting a sending station 12 and a receiving station 13. Figure 1 is in fact a very simplistic "over view" of a basic conveyor having a single sending station and a single receiving station but it is to be recognised that the features disclosed hereinafter may be incorporated into much more complex conveyor layouts having multiple sending stations, multiple receiving stations, and "in-tube" routing. Carriers 14 which are to be conveyed are generally of the form illustrated in Figure 2 and comprise an elongate tubular component having rounded leading and trailing ends, the opposite axial end regions of the carrier being encircled by annular felt sealing rings 15 which, in use, loosely engage the inner surface of the tube 11 to ensure that the carrier moves with the air flow along the tube 11. Intermediate its ends the carrier 14 is openable to introduce money, documents, or the like to be transported from the sending station 12 to the receiving station 13. Adjacent the receiving station 13 a branch pipe IS places the interior of the tube 11 in communication with the inlet of an electrically powered blower 17 which draws air through the tube 11 from the sending station 12 towards the receiving station 13. Immediately above the receiving station 13 the tube 11 contains a flap-valve which prevents air being drawn to the pipe 16 from the receiving station 13. In a basic mode of operation a carrier 14 is introduced into the tube 11 at the sending station 12 and any convenient sensor means detects the presence of a carrier 14 at the sending station and causes energisation of the blower 17. The flow of air along the tube 11 from the sending station 12 carries with it the carrier 14, and further sensor means associated with the tube 11 upstream from the pipe 16 detects the passage of the carrier 14 and de-energises the blower 17. By this time the carrier 14 has entered a vertical, or substantially vertical, region of the tube 11 above the receiving station 13 and as the carrier passes the junction with the pipe 16 it is arrested, or slowed, by the column of static air which exists within the tube 11 between the pipe 16 and the flap-valve at the receiving station 13. Thereafter, by virtue of leakage between the seals 15 and the tube wall the carrier 14 will descend slowly through the flap-valve and into the receiving station 13. It will be recognised that for any given carrier length/tube internal diameter relationship there is a minimum tube bend radius below which a carrier will not be able to negotiate a bend in the tube. In practical tests using tube of 90 mm outside diameter and 85.5 mm internal diameter the minimum bend rate when conveying a standard length carrier 14 is 330 mm (measured from the centreline of the tube 11) . Thus where, in a conventional system, the main run of the tube 11 is buried beneath floor level in a building and it is desired to have a minimum radius bend joining the horizontal run beneath floor level and a vertical run at the side of a working position such as a supermarket check-out desk then either it must be accepted that a significant proportion of the bend will be exposed above floor level, or alternatively the horizontal main run of the tube 11 must be buried at a considerable depth so that the bend is also below floor level. In practice in order to accommodate the bend, and tube connection flanges it is probable that the minimum depth of trench which must be dug in order to accommodate 90 mm tube and the bend in a conventional system is of the order of 400 mm. The various sending stations illustrated in the accompanying drawings overcome the difficulty of needing to provide such a deep trench to accommodate the tube 11. The sending station 12 illustrated in Figures 1 and 2 avoids the need for a bend interconnecting the main run of tube 11 and the location at which carriers are introduced. In its simplest aspect the sending station comprises a cabinet of rectangular cross-section extending vertically from a horizontal region of the main tube run 11 positioned immediately below floor level, and the working height of an operator, for example a cashier at a supermarket check-out. The length and width dimensions of the cabinet 18 are sufficient to accommodate a carrier 14 positioned with its axis horizontal. The top 19 of the cabinet 18 can be opened to permit a carrier 14 to be inserted in a horizontal orientation and at the lower end of the cabinet either the tube 11 extends through the cabinet (as shown in Figure 1) or the cabinet 18 seats on the tube 11 (as shown in Figure 2) or as a further alternative, the tube 11 terminates at one end of the cabinet, and the cabinet itself defines an extension of the tube. Whichever arrangement is chosen, within the confines of the sending station there is a gap 21 whereby a carrier 14 with its longitudinal axis parallel, or substantially parallel, to the adjacent tube 11 can enter the tube or the extension thereof defined within the station. In the embodiment illustrated in detail in Figure 2 the top 19 of the cabinet is opened by the operator who simply drops a carrier 14 through the open top of the cabinet with the axis . of the carrier 14 horizontal. The dimensions of the interior of the cabinet 18 guide the carrier 14 as it falls under gravity towards the gap 21. Immediate adjacent the gap 21 an inclined deflector 22 partially obscures the trailing end of the gap 21 so that the trailing end of the carrier 14 engages the deflector 22 as the carrier is entering the gap 21. The effect of the deflector 22 is to ensure that the leading end of the carrier 14 enters the gap 21 slightly ahead of the trailing end of the carrier, and additionally the deflector imparts longitudinal movement to the carrier 14 so that the seal 15 at the leading end of the carrier 14 enters the tube 11 downstream from the leading end of the gap 21. This slight "forward kick" imparted to the carrier 14 as it enters the conveyer tube within the station 12 ensures that the subsequent air flow along the tube draws the carrier 14 with it. It will be recognised that if the carrier 14 simply dropped through the gap 21 then it would seat in the lower part of the tube region within the station 12 and there would be a risk that air drawn along the tube would flow over the top of the seals 15 where they are exposed in the gap 21 with the result that the carrier would not be conveyed along the tube with the air flow. The deflector 22 prevents this happening. It will be recognised that rather than, having an opening top 19 the cabinet could have an openable flap on a side or end wall through which the carrier 14 can be introduced. In order to sense the presence of a carrier in the sending station the carrier 14 could operate a micro-switch, or an optical or magnetic transducer to signal to the control system that a carrier is present and that the blower 17 should be energised to convey the carrier. It will be understood that in a conveyor incorporating a sending station of the kind described above, because there is no bend in the tube 11 to be accommodated the depth of trench needed to accommodate the tube 11 below floor level is much reduced. For example, in relation to the 90 mm tube described above a trench of 95 mm is required, the additional 5 mm over and above the external diameter of the tube being required to accommodate overlapping joints in the tube. Provided that the leading end seal 15 of the carrier 14 enters a closed region of the tube 11 downstream of the gap 21 it is unnecessary for the lid or inlet flap of the cabinet 18 to effect a total seal. It is however desirable to effect a seal so that air is drawn through the cabinet 18 from the tube region 11a projecting upstream from the cabinet 18. The upstream portion 11a of the tube conveniently terminates at an open end covered by a filter to prevent dirt and other foreign matter being drawn into the tube when the conveyor is operating. However, in an alternative embodiment the actual tube 11 terminates at the downstream end of the cabinet, and within the cabinet it is the cabinet structure which defines the region of the tube 11 in the sending station. Where the tube 11 does not extend upstream from the sending station then the sending station itself is adapted to permit an inflow of air when the blower 17 is operating. In some applications this may be undesirable since it can generate draughts in the area occupied by the operator. Figure 3 illustrates a modification of the sending station illustrated in Figure 2 in that a loading mechanism 23 is provided at the inlet of the station 12. Adjacent the upper end of the cabinet 18 and parallel to the tube 11 there is provided a receiver 24 in the form of a length of tube closed at both ends and pivoted for rotation about its longitudinal axis in bearings in the wall of the cabinet 18. The tube defining the receiver 24 is cut away so that throughout substantially the whole of its length only half of the circumference of the tube is present. An electric drive motor 25 can be energised to rotate the receiver 24 relative to the cabinet 18. The diameter of the tube defining the receiver 24 is equal to the width of the interior of the cabinet and thus when the receiver is in a position as shown in Figure 3 with its open top presented upwardly, the receiver 24 effectively seals the cabinet so that no air can flow to the tube 11 between the receiver and the cabinet walls. The end surfaces of the receiver 12 and the longitudinal edges thereof (or the corresponding surface of the cabinet) can be provided with felt seals to enhance this sealing effect. The top of the cabinet can be open, but conveniently has a lid which must be raised to gain access to the receiver. An operator lifts the lid of the cabinet and places a carrier 14 into the receiver 24. Closure of the lid operates a micro-switch or similar sensor to produce a control signal applied to the conveyor control mechanism firstly to energise the motor 25 to rotate the receiver 24 and thereafter to energise the blower 17. The receiver 24 rotates through 180° so that the carrier falls from the receiver 24 and drops, under gravity with its axis parallel to the axis of the receiver 24 and the tube 11 towards the gap 21. As described above the upstream end of the gap 21 is partially obscured by an inclined deflector 22 which ensures that the leading end of the carrier 14 enters the tube 11. The air flow generated by the blower 17 then transports the carrier along the tube 11. It will be understood that if desired the control mechanism can ensure that the receiver 24 is rotated back to its rest position, or through an addition 180° to reach its rest position before the blower 17 is energised. Moreover, control of energisation of the blower 17 could be separate from control of the motor 25 and could be dependent upon a signal from a sensor detecting the presence of a carrier within that portion of the tube 11 within the sending station. Figure 4 illustrates a further alternative sending station 32 having a cabinet 33 similar to the cabinet 18 described above. A receiver 34 defined by a section of tube within the cabinet 33 (disconnected from the tube 11 and its upstream extension 11a) is movable vertically within the cabinet 33 from a position in which it is co¬ extensive with the tube 11 to a raised position adjacent the lid 35 of the cabinet 33. Apertures in the end walls of the cabinet 33 ensure that the tube 11 is continuous when the receiver 34 is in its lowermost position. A rack and pinion mechanism 36 driven by an electric motor 37 can raise the receiver 34 bodily, maintaining its axis parallel to the axis of the tube 11, and as is apparent from Figure 5 the rack of the mechanism 36 will raise the lid 35 as the receiver 34 is raised. The tube section defining the receiver 34 is cut away on its upper surface to provide a gap 38 through which a carrier can be inserted to lie within the receiver 34. A closure member (not shown) coacts with the receiver 34 to close the gap 38 when the carrier is to be conveyed. The mode of operation of the station illustrated in Figures 4 and 5 is as follows. The motor 37 is operated to raise the receiver 34 and at the same time to open the lid 35 of the cabinet 33. The closure member of the receiver 34 is simultaneously moved to its open position and when the receiver 34 reaches the top of its vertical movement an operator can insert a carrier 14 by way of the open gap 38. Either by means of a sensor in the receiver 34 detecting the presence therein of a carrier 14, or alternatively a manually operable control switch operated by the user, a signal is given to the conveyor control mechanism to reverse the operation of the motor 37 and lower the receiver 34 to its position co-extensive with the tube 11. During this lowering moving the cabinet lid 35 closes and the closure member of the receiver 34 is returned to its closed position. As the receiver 34 reaches its lowermost position the blower 17 is energised, and since the gap 38 has now been closed by the closure member the air flow along the tube 11 draws the carrier 14 from the receiver 34 and along the tube 11 to the receiving station. A convenient closure arrangement for the gap 38 of the receiver 34 is a second, coaxial tube portion within which the tube section 34 is received. The outer tube will have a gap corresponding to the gap 38 and the gap 38 will be closed in use by rotating the outer tube on the tube section 34 so that a closed portion of the outer tube overlies the gap 38. Rotation of the outer tube to its open and closed positions can be achieved by any convenient mechanism, for example a further electric motor and gear arrangement the gear meshing with teeth on the outer tube when the tube section 34 is in its uppermost position. It will be recognised that the sending station illustrated in the previous examples may operate without a cabinet structure provided that there is some guide structure for ensuring that the carrier moves vertically, with its axis generally horizontal. However it is preferred to have a cabinet for aesthetic and safety reasons. The sending station illustrated in Figures 6 and 7 does not have an enclosing cabinet, but could be provided with one if desired. Again for aesthetic and safety reasons it may be desirable to incorporate a cabinet, but it will be understood that operation of the station does not require the presence of a cabinet. In the station illustrated in Figures 6 and 7 the tube 11 is coextensive with a tube section in the sending station, the tube section in the sending station having a gap 21 by way of which the carrier enters the tube. Pivotally connected adjacent the downstream end of the gap 21 is a carrier receiving tube 41 hingeable between a receiving position (Figure 6) and a conveying position (Figure 7) . The outer diameter of the receiving tube 41 and the size of the gap 21 in the tube 11 is such that the tube 41 can hinge from a position at which its extends vertically upwardly from the gap 21 to a position in which it lies within the tube 11 with its axis co-extensive with the axis of the tube 11. Thus when it is desired to convey a carrier 14 the operator either manually, or by means of an electric drive arrangement, raises the tube 41 so that it presents an open end uppermost adjacent the operators working position. The operator then simply drops a carrier 14 axially into the open end of the receiving tube 41 and a signal is then given to the conveyor control mechanism either by a sensor detecting the presence of a carrier in the tube 41 or by a manual control switch operated by the operator to pivot the receiving tube 41 relative to the tube 11 to its lowermost position in which the tube 41 (containing the carrier) swings through the gap 21 and into the tube 11. In this position of course the lower end of the tube 41 opens into the main downstream run of tube 11 and the wall of the tube 41 closes the gap 21 of the tube 11. Thus energisation of the fan 17 will draw the carrier 14 from the tube 41 and long the tube 11. Naturally if desired movement of the tube 41 between its limit positions could be effected manually, and the signal to cause energisation of the blower 17 could be generated by a sensor or switch detecting the tube 41 in its lowermost position. It will be recognised that there will be many practical embodiments where the conveyor system includes a plurality of sending stations feeding into a common tubing system, and perhaps supplying a common receiving station. In order to * ensure that the conveyor system operates efficiently it is desirable to minimise the leakage of air into the system at the sending stations. More specifically, when a sending station is not the currently active sending station then any air leakage which occurs at that station detracts from the efficiency of the overall system. Figures 8 and 9, and Figures 10 and 11 illustrate two alternative constructions whereby air leakage may be minimised when the station is not the active station of a conveyor system, but of course measures may be taken in the stations illustrated in Figures 1 to 7, to minimise leakage in the station when it is not the active station. Referring first to Figures 8 and 9 the sending station includes a rectangular cabinet 51 the lower region of which accommodates the main tube run. The tube 11 of the main tube run extends through the cabinet, and within the cabinet is cut away to define a gap 52 whereby a carrier of the kind described above, with its longitudinal axis parallel, or substantially parallel, to the tube 11 can enter the tube from within the cabinet. The air flow direction within the tube 11 is indicated by the arrow at the left of Figure 8, and is from right to left. For convenience therefore, and with reference to Figures 8 and 9, the left hand end of the cabinet will be referred to as the downstream end while the right hand end of the cabinet 51 is referred to as the upstream end. A tube 53 similar in structure to the tube 11 enters the cabinet 51 at the upstream end thereof parallel to the main tube run 11. The tube 53 enters adjacent the upper part of the cabinet 51 and a carrier introduced into the tube 53 manually is held by an electrical retaining mechanism against passage into the cabinet 51 until the mechanism is released by a main, system control mechanism. Within the cabinet 51 is a hinged flap 54 movable between a rest position (indicated in Figure 8 by double broken lines) and an operative position (indicated in Figure 1 by a chain dotted line) under the influence of an electric drive motor 55. The flap is hinged at the downstream end of the gap 52 in the tube 11 and is shaped to close the gap 52 in the rest position. Thus in the rest position of the flap 54 there is no leakage of air into the tube 11 from the cabinet. When it is desired to introduce a carrier from the tube 53 into the tube 11, and the system control mechanism determines that the system is clear to receive such a carrier, then a signal is sent to the motor 55 to drive the flap 54 to its upper, operative position. As the flap reaches its upper position the latch mechanism retaining the carrier in the tube 53 is released and of course the front end of the carrier in the tube 53 is now subject, by virtue of the open gap 52, to the reduced air pressure within the pipe 11. Ambient air pressure behind the carrier in the tube 53 drives the carrier into the cabinet 51 where the front end of the carrier strikes the under surface of the flap 54 and is deflected thereby through the gap 52 into the tube 11 so as to be conveyed along the tube 11 by the air flow. It will be recognised that although the carrier is deflected by the flap 54 it is still nevertheless substantially parallel to the tube 11, and falls laterally relative to the axis of the tube 11 into the gap 52. When the carrier has reached its destination the system control mechanism signals the motor 55 to return the flap 54 to its rest position closing the gap 52 and preventing further air flow into the tube 11 through that particular sending station. The upstream part 11a of the tube 11 may carry other sending stations similarly "leak- proofed" . Depending upon the nature of the conveyor system upstream of the station the flow of air in the tube 11 can be provided either through the tube part 11a, in which event the flap 54 could be closed immediately after the carrier has entered the tube 11, or through the tube 53 and cabinet 51, in which event the flap 54 is held open until the carrier has reached its destination. The arrangement illustrated in Figures 10 and 11 is based upon the construction illustrated in Figure 3, and like parts carry the same reference numerals. There are however two fundamental points of distinction over the construction described with reference to Figure 3, firstly in that the receiver 24 seats in a part cylindrical support 61, and secondly in that the drive mechanism of the receiver 24 is arranged to lift the receiver 24 bodily relative to the support 61 prior to rotating the receiver 24. More specifically the cabinet 18 is divided internally by a horizontally extending wall 60 including an integral part cylindrical support 61. The axis of curvature of the support 61 is coincident with the axis of the receiver 24 when the receiver is in a rest position, and the radius of curvature of the support 61 is larger than that of the receiver 24. The support 61 is formed with a rectangular aperture 62 large enough to permit a carrier, with its axis parallel to the axis of the tube 11, to pass through, but small enough to be closed by the solid wall region of the receiver 24. Positioned around the aperture 62, on the upper surface of the support 61 is a resilient sealing strip 63 against which the solid cylindrical wall region of the receiver 24 seats in the rest position of the receiver. It will be recognised that when the receiver 24 seats against the seal 63 then the lower part of the cabinet 18, containing the main tube run 11, is closed, and air cannot enter the tube 11 through the cabinet. When it is desired to convey a carrier from the station the lid of the cabinet (not shown) is raised so that the operator can place the carrier into the open top of the receiver 24. Subsequent closure of the lid signals to the control system that a carrier is to be conveyed, and when the control system recognises that the conveyor system is ready to receive that carrier it sends a signal to the drive motor of the receiver 24 to initiate operation of the drive mechanism. The first stage in operation of the drive mechanism is to lift the receiver 24 relative to the support 61 thereby lifting the cylindrical wall of the receiver 24 off the seal 63. Immediately thereafter the receiver 24 starts to rotate about its longitudinal axis and since the receiver 24 is lifted away from the seal 23 air can flow through the cabinet 17 into the tube 11. The lid of the cabinet does not form an effective seal in this respect. As the receiver 24 rotates a point is reached at which the carrier can fall through the open part of the receiver 24 and through the rectangular aperture 62 of the support 61 whereupon the operation is similar to that described above in relation to the Figure 3 embodiment. As the carrier, positioned with its axis parallel to the axis of the tube falls laterally with respect to the tube its trailing end hits the deflector 22 so that the leading end of the carrier 14 enters the tube 11 through the gap 21 thereby ensuring that the carrier enters the tube 11 correctly to be carried by the air flow along the tube. During this phase of the operation there is a clear air flow path through the support 61 since the open region of the receiver 24 is presented to the support surface 61 and air can flow freely through the aperture 62. When the carrier is received by the receiving station the control system generates a signal which is supplied to the drive mechanism with the carrier 14 to rotate the carrier 14 back to its original position (that is to say with its open region uppermost) and thereafter to lower the receiver 24 towards the support 61 so that the solid cylindrical surface of the receiver 24 abuts the seal 63 around the aperture 62 thus sealing the aperture and preventing air flow into the tube 11 through the cabinet 18. The comments made above in relation to the operation and the nature of the conveyor system upstream of the station (in relation to Figures 7 and 8) apply also to Figures 9 and 10. It will be recognised that in all of the station designs described above the region of the tube 11 within the station can be an integral part of the tube 11 which extends away from the sending station, or alternatively can be a separate tubular component co-extensive with the tube 11. As a further alternative the tube region within the sending station can be defined by the cabinet (see for example Figures 4 and 5 where the lower region of the cabinet 33 effectively defines the tube region into which carrier 14 is lowered by the receiver 34) , or some other component of the sending station itself. references herein to "tube" and "tube region" are to be construed accordingly. When installing buried tubes preferably blanking sections will be incorporated at intended sending station locations and these will be replaced by prefabricated sending stations at an appropriate time, connections between the tube main run and tube regions of the stations being effected by sliding collars overlying the tube 11. Industrial Applicability While it will be recognised that the various constructions described above lend themselves particularly advantageously to overcoming the problems of burying the conveyor tube below floor level, the arrangements could also find advantage in other conveyor environments. For example, it would be possible to use a minor variant of the station illustrated in Figures 4 and 5 to lift a carrier 14 vertically upwardly into a tube run housed in a ceiling void.

Claims: CLAIMS 1- An air- ube conveyor comprising a sending station (12) at which a carrier (14) enters the conveyor, and, an elongate conveyor tube (11) extending from the sending station (12) and along which the carrier is conveyed in use, there being a tube region within the sending station having an elongate gap in the wall thereof corresponding in length to the length of the carrier, the conveyor being characterized in that the sending station (12) has inlet means spaced laterally from the axis of said tube region for the introduction of a carrier (14) , and, the sending station is arranged to convey a carrier introduced at said inlet, laterally with respect to said tube region axis, to introduce the carrier in an orientation substantially parallel to said tube region axis through said gap into said tube region. 2. A conveyor as claimed in Claim 1, characterized in that said sending station has a movable receiver (34; 41) for carrying the carrier (14) into said tube region. 3. A conveyor as claimed in Claim 2, characterized in that said receiver (34) is movable bodily, vertically in use, to carry the carrier (14) into said tube region. 4. A conveyor as claimed in Claim 2, characterized in that said receiver (41) is pivoted so as to carry said carrier (14) through an arc from an inlet position at an angle to the axis of said tube region to enter said tube region parallel to the axis thereof. 5. A conveyor claimed in Claim 1, characterized in that said sending station includes guide means (18; 33, 36; 51) extending at right angles to said tube region between the inlet location of the sending station and said tube region, said guide means being arranged to guide a carrier (14) for movement between the inlet location and the tube region with the longitudinal axis of the carrier parallel to the axis of said tube region. 6. A conveyor as claimed in Claim 5, characterized in that said guide means (18, 51) guides the carrier for movement under gravity. 7. A conveyor as claimed in Claim 6, characterized in that said gap (21) in the wall of said tube region is substantially equal in length to the carrier length and at the upstream end of the gap in relation to the direction of movement of the carrier (14) along the tube, there is provided a deflector (22) engaged by the trailing end of the carrier as the carrier passes through the gap, the deflector ensuring that the leading end of the carrier enters the tube region, and the deflector simultaneously imparting longitudinal movement to the carrier so that as the carrier passes through the gap it is moved lengthwise of the tube region. 8. A conveyor as claimed in Claim 1, characterized by including means for sealing the tube region against inlet of air from the sending station when the sending station is not active in the conveying of a carrier. 9. A conveyor as claimed in Claim 1, characterized in that the sending station includes a carrier receiver (24) for receiving a carrier (14) with its axis parallel to and spaced from the axis of said tube region, and means for rotating the receiver (24) about its longitudinal axis to release said carrier for movement laterally of said tube region through the gap thereof. 10. A conveyor as claimed in Claim 9, characterized in that said receiver (24) is mounted in a cabinet (18) spaced from said tube region and seats, in a rest position, against seal means (62, 63) to seal the cabinet (18) to prevent flow of air into said tube region by way of the cabinet, there being drive means for moving said receiver (24) dispense a carrier placed in the receiver, through the tube region gap (21) , and said drive means, when operative, displacing the receiver away from said seal means (62, 63) prior to rotating the receiver to dispense the carrier.

Inventors: CLIFFORD NORMAN SAMUEL, HENDERSON FRASER, CLIFFORD, NORMAN, SAMUEL, HENDERSON, FRASER
Applicants: AIR TUBE CONVEYORS, AIR TUBE CONVEYORS LIMITED
Application year: 1993
Main classification: B65G51
IPC codes: B65G51