There are many industries which employ hoses and the like wherein internal cleaning is essential, or would result in substantial savings by eliminating replacement costs. For example, in the food and medical industries, it may be critical to carry out regular maintenance on hoses and the like for hygienic and sanitation reasons. Similarly, in heavy duty machinery which employ hydraulic and/or pneumatic lines, internal contamination in the hydraulic and pneumatic lines can cause breakdown and costly downtime.

In this specification, the term"hose"is used in a generic sense and will be understood to mean a hose, tube, pipe, hydraulic or pneumatic line, or similar.

It is known to clean a hose by forcing a compressible projectile through the hose, the outside diameter of the projectile being equal to or greater than the internal diameter of the hose. The projectile is compressed by means of a specifically designed nozzle. As the projectile travels along the hose it cleans the hose by removing particulate material from the internal wall of the hose. A number of projectiles can be repeatedly passed through the hose under pressure to ensure that all contaminate matter has been removed.

One way of forcing such projectiles through a hose is to place the projectile in a manually operated compressed air gun and to operate the gun so as to cause compressed air to flow through the gun and into the tube via a nozzle coupled to the end of the hose.

The compressed air forces the projectile into the nozzle and through the tube so as to thereby clean the interior of the tube.

It is estimated that a worker using such a manually operated pneumatic gun can achieve a relatively high discharge rate. However, in some situations wherein a high number of

projectiles are required in order to carry out a cleaning operation, there is a considerable risk of significant operator fatigue, and increased labour costs if a number of workers are required.

Throughout this specification the term"comprising"is used inclusively, in the sense that there may be other features and/or steps included in the invention not expressly defined or comprehended in the features or steps subsequently defined or described. What such other features and/or steps may include will be apparent from the specification read as a whole.

In accordance with an aspect of the present invention, there is provided an automatic pneumatic projectile launching system for automatically launching cleaning projectiles into a hose, said system comprising: a launcher housing defining a chamber; a shuttle having a recess for receiving a projectile and a first shuttle aperture in fluid communication with the recess, the shuttle being disposed in and being reciprocably moveable relative to the chamber between a first position wherein a projectile is receivable in the recess and a second position wherein the first shuttle aperture is communicable with a source of compressed air; a feeder mechanism for transferring projectiles to the shuttle; projectile releasing means for selectively releasing a projectile into the recess; and logic control means operatively connected to the projectile releasing means for activating the projectile releasing means so as to release projectiles one at a time into the recess.

Preferably, the shuttle includes a second aperture for receiving a stand-off pin, the stand- off pin being moveable from an extended position wherein a projectile is permitted to be only partially received in the recess, and a withdrawn position wherein the projectile is permitted to be fully received in the recess. The system may include means for effecting movement of the stand-off pin between the extended position and the withdrawn

position. A stand-off cylinder and associated stand-off rod may be provided to cooperate with the stand-off pin so as to effect movement of the stand-off pin between the extended position and the withdrawn position. For this purpose, the stand-off pin may include a ferrous portion and the stand-off rod may include a magnet. Means may be provided for sensing when the stand-off rod is in an extended position or a contracted position.

Preferably, the launcher is provided with projectile sensing means for sensing whether a projectile is received in the recess. The projectile sensing means may take the form of a third aperture extending through the shuttle and an optical sensor, the optical sensor being arranged to sense when a light beam passing through the third aperture is broken by a projectile received in the recess.

Preferably, the system further includes a source of compressed air for ensuring that a projectile is fully received in the recess when the stand-off pin is moved from the extended position to the withdrawn position.

Preferably, the launcher includes a first proximity sensor arranged to sense when the shuttle is in the first position and a second proximity sensor arranged to sense when the shuttle is in the second position.

Preferably, the launcher housing includes a first housing aperture extending into the chamber and a second housing aperture extending into the chamber, the first housing aperture aligning with the first shuttle aperture and the recess aligning with the second housing aperture when the shuttle is in the second position.

Preferably, the feeder mechanism includes a helical track for guiding projectiles towards the shuttle. Alternatively, the feeder mechanism may include an inclined plate for guiding projectiles towards the shuttle. In one arrangement, the feeder mechanism includes a transition block defining a track twisted through approximately 45°, and an adjacently disposed V-shaped block defining a V-shaped track.

Preferably, projectile releasing means includes a clamping device for selectively releasing a projectile into the recess under control of the logic control means. The clamping device may include a pivotably mounted arm portion and biasing means arranged to bias the pivotably mounted arm portion into contact with a projectile located in use adjacent the recess. The projectile releasing means may further include means for selectively urging the arm portion to move out of contact with a projectile located in use adjacent the recess so that the projectile is freely movable into the recess. The urging means may include a clamp cylinder and associated clamp rod reciprocably moveable relative to the clamp cylinder towards and away from the arm portion under control of the logic control means.

In order to facilitate a better understanding of the nature of the invention a preferred embodiment of the automatic projectile launching system will now be described in detail, by way of example only, with reference to the accompanying drawings in which: Figure 1 is diagrammatic cross-sectional view of an automatic projectile launching system in accordance with an embodiment of the present invention; Figure 2 is a diagrammatic perspective view of parts of the launching system shown in Figure 1 ; Figure 3 and 4 are diagrammatic perspective views of the automatic projectile launching system shown in Figure 1 ; and Figure 5 is a diagrammatic perspective view of parts of the launching system shown in Figure 1.

The accompanying drawings illustrate an embodiment of an automatic pneumatic projectile launching system 10 in accordance with the present invention for automatically launching compressible cleaning projectiles into a hose, pipe, tube or

similar, hereinafter referred to as a"hose". The projectiles are typically manufactured from variable density foamed material, examples of which are described in US patent No. 5,555, 585.

The launcher 10 includes a block portion, in this example in the form of a shuttle 12, reciprocably moveable in a generally cylindrical chamber 14 formed in a launcher housing 16. The shuttle 12 is connected to a pneumatic ram 18 arranged to cause the shuttle 12 to reciprocally move in the chamber 14 during use.

The launcher 10 also includes a feeder mechanism 20 arranged to receive projectiles and to guide the projectiles towards the shuttle 12 during use.

The shuttle 12 includes a recess 22 of suitable shape to receive a projectile (not shown), the recess 22 having a first shuttle aperture 24 in communication with an outwardly facing surface 26 of a side of the shuttle 12 opposite to the recess 22. The recess 22 is also provided with a second shuttle aperture 28 in which is moveably received a stand- off pin 30, and a third shuttle aperture 32 extending through the shuttle 12 in a direction generally perpendicular to the direction of movement of the shuttle 12 during use.

The launcher housing 16 includes a first housing aperture 34 in communication with the chamber 14, a second housing aperture 36 in communication with the chamber 14, and a third housing aperture 37 in communication with the chamber 14. The first housing aperture 34 is arranged to connect to a source of compressed air. The second housing aperture 36 is disposed at a location generally diametrically opposite to the first housing aperture 34. Disposed in the second housing aperture 36 is a nozzle 38 which connects, in use, to a hose, pipe or tube and through which projectiles pass during use.

Mounted on the launcher housing 16 is a stand-off cylinder 40 which is arranged to selectively extend or withdraw a stand-off rod 42 relative to the stand-off pin 30. An end of the stand-off rod 42 remote from the stand-off cylinder 40 is provided with engaging means, in this example a magnet, which enables the stand-off rod 42 to engage

with a ferrous portion of the stand-off pin and effect withdrawal of the stand-off pin 30 relative to the recess 22.

As shown more preferably in Figures 3 and 4, the feeder mechanism 20 includes a helical track 41, a bridging track portion 43, a transition block 44 which defines a track twisted through approximately 45°, and a V-shaped block 46 defining a V-shaped track across which projectiles pass during use. The bridging track portion 43 acts as a discriminator and ensures that the projectiles pass onto the transition block 44 in the correct orientation. In order to activate this function, the bridging track portion includes first and second flanges 45,47, the first flange 45 serving to ensure that all projectiles are oriented such that longitudinal axes of the projectiles locate in the same generally vertical place, and the second flange 47 serving to ensure that all projectiles are oriented such that the longitudinal axes of the projectiles locate in the same generally vertical place and extend in the same generally horizontal direction towards the transition block 44. The V-shaped track ensures that the projectiles all lie at the same position relative to the recess 22 when the shuttle 12 locates in the position shown in Figure 1. It will be understood that instead of a helical track 41, an inclined plate arrangement may be used to carry projectiles to the bridging track portion 43.

It will be understood that the shuttle 12 is moveable from a first position, as shown in Figure 1, wherein the recess 22 aligns with the third housing aperture 37 and with the V- shaped block 46, and the stand-off rod 42 aligns with the stand-off pin 30, and a second position (not shown) wherein the recess 22 aligns with the nozzle 38 and the first shuttle aperture 24 aligns with the first housing aperture 34. In this way, when the shuttle is in the first position, a projectile may be received in the recess 22, and when the shuttle 12 is in the second position, the projectile may be launched through the nozzle 48 by forcing compressed air through the first housing aperture 34.

In order to control the launcher 10 so that only one projectile at a time is loaded into the launcher and so that movement of the shuttle 12 between the first and second positions is synchronised with projectile loading, a logic control unit 49 is provided, the logic

control unit 49 being responsive to signals generated by sensors in accordance with pre- programmed control logic.

The pneumatic ram 18 is provided with a first sensor in the form of a first proximity switch arranged to detect when the shuttle 12 is in the first position, and a second sensor in the form of a second proximity switch arranged to detect when the shuttle 12 is in the second position.

The third shuttle aperture 32 is associated with a third sensor in the form of an optical sensor 33 arranged to sense when a projectile is in the recess 22 by detecting when a light beam passing through the third shuttle aperture 32 is broken by a projectile as the projectile enters the recess 22.

A fourth sensor in the form of a proximity sensor is also provided in relation to the stand-off rod 42 and the stand-off cylinder 40 so as to sense when the stand-off rod 42 is fully withdrawn from the shuttle 12.

Accommodated on the launcher 10 is a projectile releasing means, in this example a clamping device 50 shown more particularly in Figure 5, for selectively releasing a projectile into the recess 22.

The clamping device 50 includes a pivotably mounted arm portion 52, a clamp member 54, a clamp cylinder 56, and a spring 58.

The clamping device 50 operates such that the clamp member 54 is pivotable towards and away from a projectile disposed, in use, on the V-shaped block 46 so as to clamp or release the projectile. The arm portion 52 and thereby the clamp member 54 is biased towards the V-shaped block 44 by the spring 58, and the arm portion 52 may be urged to pivot so as to move the clamp member 54 away from the V-shaped block 46 by extending a clamp rod of the clamp cylinder 56. The clamping force is provided by a spring so as to ensure that excessive force is not applied to the projectiles.

As shown more particularly in Figures 3 and 4, the launcher 10 is provided with a quick release retaining means, in this example in the form of a pivotable retaining arm 60.

The retaining arm 60 includes a lever portion 62 and a curved retaining portion 64, the retaining arm 60 being pivotably mounted to the launcher housing 16 at pivot 66. In use, the retaining arm 60 is pivotable between a first location shown in Figures 3 and 4 wherein the nozzle 38 is removable from the second housing aperture 36, and a second location (not shown) wherein the retaining portion 64 engages with the nozzle 38 to prevent removal of the nozzle 38 from the second housing aperture 36.

Operation of the launcher 10 will now be described with reference to the Figures.

Compressible foam projectiles are pushed up the helical track 41 and along the bridging track portion 43. Any projectiles which are not oriented such that a longitudinal axis of the projectile extends in a generally horizontal direction towards the transition block 44 are caused to move to this orientation by the bridging track portion 43. The projectiles then travel along the transition block 44 and the V-shaped block 46 until a projectile contacts the stand-off pin 30 in the recess 22. This causes the optical sensor 33 to generate a signal indicative of the presence of a projectile in the recess 22. In response to the signal, the logic control unit 49 causes the clamping device 50 to hold a projectile immediately adjacent the projectile disposed in the recess 22, and the stand-off rod 42 of the stand-off cylinder 40 to withdraw the stand-off pin 30 from the aperture 22.

Although the stand-off pin 30 is only permitted to partially withdraw, the stand-off rod 32 continues to move so as to completely withdraw from the shuttle 12.

When withdrawal of the stand-off pin has ceased, an air jet (not shown) may be activated by the logic control unit 49 so as to ensure that the projectile travels further into the recess 22 when the stand-off pin has fully withdrawn from the recess 22.

The proximity sensor associated with the stand-off cylinder 40 then generates a signal indicative that the stand-off rod 42 has fully withdrawn from the shuttle 12, this signal

being used by the logic control unit 49 to activate the pneumatic ram 18 to cause the shuttle 12 to move from the first position (shown in Figure 1) to the second position wherein the recess 22 aligns with the nozzle 38 and the first shuttle aperture 24 aligns with the first housing aperture 34. When the shuttle 12 has reached the second position, the second proximity switch is triggered so as to generate a signal indicative that the shuttle 12 is in the second position, this signal being used by the logic control unit 49 to deactivate the air jet and enable a triggering mechanism (not shown) of a compressed air supply connected to the launcher 10.

With the triggering mechanism enabled, when a trigger on the compressed air supply is pressed, compressed air is forced through the first housing aperture 34, the first shuttle aperture 24 and into the recess 22 to thereby force the projectile out of the recess 22 and through the nozzle 38.

After a predetermined time period which is sufficient for the projectile to pass through the hose connected to the nozzle 38, the pneumatic ram 18 under control of the logic control unit 49 moves the shuttle 12 back to the first position. This causes the first proximity switch to generate a signal indicative that the shuttle 12 is in the first position, this signal being used by the logic control unit 49 to cause the stand-off rod 42 to extend and thereby the stand-off pin 30 to extend into the recess 22, and the clamping device 50 to be released. Releasing the clamping device 50 causes the previously held projectile to move into the recess 22. The above steps of operation of the launcher 10 then repeat.

All variations and modifications as would be apparent to a skilled addressee are to be considered within the scope of the present invention, the nature of which is to be determined from the foregoing description.