WO2002081109A1 - Automatic pneumatic projectile dispensing system - Google Patents

Abstract

An automatic pneumatic projectile dispensing system (10) is disclosed for automatically dispensing cleaning projectiles (36) into a hose, pipe or tube. The system comprises a hopper (12) for receiving projectiles (36), the hopper having an opening (14) adjacent a lower end of the hopper coupled to an elongate magazine (16), and a projectile feeding mechanism (20) for feeding projectiles (36) through the opening (14) into a first longitudinal end of the magazine (16). The system (10) also comprises a launcher (30) having a breech block (32) with a recess (34) adapted to receive a projectile (36) from a second opposite longitudinal end of the magazine (16), the recess (34) being adapted to communicate with an air chamber of the launcher (30), and the projectile (36) being launched into the hose, pipe or tube when a source of compressed air is connected to the air chamber. The system further comprises projectile releasing means (50) associated with the magazine (16) for releasing a projectile (36) into the recess (34) and logic control means (60) operatively connected to the projectile releasing means (50) for activating the projectile releasing means (50) when a projectile (36) is not received in the recess (34) so that, in use, only one projectile (36) at a time is loaded into the recess (34).

Description

AUTOMATIC PNEUMATIC PROJECTILE DISPENSING SYSTEM

The present invention relates to an automatic pneumatic projectile dispensing system for automatically dispensing cleaning projectiles into a hose, pipe or tube with compressed air.

There are many industries which employ hose, tube, conduit or piping where internal cleaning is essential, or would result in substantial savings by eliminating replacement costs. The importance of keeping hoses, tubes or pipework internally clean cannot be underestimated. Where the hose or tube is used for example in the food industry or in a medical environment, it is critical from a hygienic and sanitation point of view that the lines remain clean. Similarly, in hydraulic and pneumatic lines internal contamination can cause breakdown and costly downtime.

A very efficient known means of cleaning hose and tube is to force a compressible projectile therethrough, the outside diameter of the projectile being greater than the internal diameter of the hose or tube. The projectile is compressed by means of a specifically designed nozzle. As the projectile travels along the hose or tube it removes particulate material from the internal wall. A number of projectiles can be repeatedly passed through lengths of hose or tube under pressure to ensure that all contaminate matter has been removed. The usual means of effecting this cleaning operation is to place the projectile in a manually operated compressed air gun and then to operate a hand or foot actuated valve causing compressed air to flow through the gun and enter the tube via a nozzle that is coupled to the end of the hose or tube. The compressed air forces the projectile through the nozzle into and along the pipe to clean the interior of the pipe.

It is estimated that a worker using a hand held pneumatic gun can achieve a discharge rate of up to 900 projectiles per hour, including the time taken for manual loading and firing of projectiles. This does not include the time taken for changing the size of nozzle and projectiles employed. In some industries, for example, large hose manufacturing plants, each hose must be cleaned internally while on the production line before it leaves the factory. This may require up to 100,000 projectiles to be fired per day. It will be appreciated that such a large number of cleaning operations per day quickly leads to operator fatigue and increased labour costs in view of the number of workers required to manually operate hand held pneumatic guns.

Commonly owned international application number PCT/AU98/00903 describes an automatic pneumatic projectile launcher having a moveable hopper with an opening provided at a lower end thereof coupled to a feed tube. The hopper is moved up and down vertically in a reciprocating motion by four double acting pneumatic rams. The feed tube acts as a magazine for the projectiles and is slidably received through the hopper base plate so that it projects upwardly into the hopper during a downward stroke. Projectiles are gravity fed via the feed tube into a self-loading mechanism for loading each projectile into an air chamber. Whilst the automatic pneumatic projectile launcher of PCT/AU98/00903 operates satisfactorily, the hopper is bulky and the machine has many moving parts. It is also relatively expensive to manufacture.

The present invention was developed with a view to providing automatic pneumatic projectile dispensing system that eliminates fatigue and operates more reliably than prior art systems.

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.

According to one aspect of the present invention there is provided and an automatic pneumatic projectile dispensing system for automatically dispensing cleaning projectiles into a hose, pipe or tube, the system comprising: a hopper for receiving projectiles, said hopper having an opening adjacent a lower end of the hopper coupled to an elongate magazine, and a projectile feeding mechanism for feeding projectiles through said opening into a first longitudinal end of the magazine; a launcher having a breech block with a recess adapted to receive a projectile from a second opposite longitudinal end of the magazine, said recess being adapted to communicate with an air chamber of the launcher, and the projectile being launched into the hose, pipe or tube when a source of compressed air is connected to the air chamber; projectile releasing means associated with the magazine for releasing a projectile into the recess; and

logic control means operatively connected to the projectile releasing means for activating said projectile releasing means when a projectile is not received in the recess so that, in use, only one projectile at a time is loaded into the recess.

Advantageously the system further comprises a projectile sensing means associated with the magazine for sensing when a projectile is present at said second end of the magazine, said projectile sensing means being operatively connected to the logic control means. Preferably said logic control means does not activate said projectile releasing means unless the projectile sensing means senses that a projectile is present at said second end of the magazine.

Preferably said projectile sensing means comprises a first sensor located at said first end of the magazine and a second sensor located at said second end of the magazine, and wherein said first sensor is adapted to sense when the magazine is full of projectiles. Preferably said projectile feed mechanism is operatively connected to said logic control means, wherein said projectile feeding mechanism is deactivated when the first sensor senses that the magazine is full.

Advantageously said magazine is in the form of a variable aperture chute adapted to receive various diameter projectiles therein, arranged end to end. Preferably said variable aperture chute is provided in a substantially vertical orientation with said first end aligned with the opening at the lower end of the hopper. In one embodiment said projectile feeding mechanism comprises a movable distributor plate having a plurality of feed apertures provided therein, each of said feed apertures being adapted to receive a single projectile therein in a predetermined orientation. Typically, when said projectile feeding mechanism is activated, the movable distributor plate is periodically moved so as to cause each of said feed apertures to be repositioned, so that a different feed aperture becomes aligned with said opening in the lower end of the hopper after each movement.

In order to facilitate a better understanding of the nature of the invention a preferred embodiment of the automatic projectile dispensing system will now be described in detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a preferred embodiment of the automatic projectile dispensing system in accordance with the invention;

Figure 2 is a perspective view of a variable aperture chute employed in the automatic projectile dispensing system of Figure 1 ; and,

Figure 3 is a cross-sectional view through a launcher employed in the automatic projectile dispensing system of Figure 1.

The accompanying drawings illustrate a preferred embodiment of an automatic pneumatic projectile dispensing system 10 in accordance with the present invention for automatically launching compressible cleaning projectiles into a hose, pipe or tube. The projectiles are typically manufactured from variable density foamed material, examples of which are described in commonly assigned US patent No. 5,555,585. The automatic projectile dispensing system 10 comprises a hopper 12 having an opening 14 provided at a lower end thereof coupled to an elongate magazine 16. In this embodiment, the magazine 16 is in the form of a variable aperture chute which can be seen more clearly in Figure 2. The chute of the magazine 16 has a moveable, arcuate wall section 18 that can be moved in and out to vary the aperture of the chute to suit various diameter projectiles. Preferably, with the wall section 18 in its outer most position, as shown in Figure 2, the mouth of the chute forms a substantially circular aperture having a diameter slightly larger than that of the largest projectiles fired by the launcher. As the wall section 18 is moved inwards, the mouth of the chute no longer forms a perfectly circular aperture, however the maximum width dimension of the aperture can be made slightly larger than the outside diameter of the different sized projectiles to be fired from the launcher. In this embodiment, the magazine 16 is arranged in a substantially vertical orientation with its upper end aligned with the opening 14 in the lower end of the hopper 12.

The hopper 12 is also provided with a projectile feeding mechanism 20 in connection therewith, for feeding projectiles through the opening 14 into upper end of the magazine 16. In this embodiment, the projectile feeding mechanism 20 comprises a movable distributor plate 22 having a plurality of feed apertures 24 provided therein. In the illustrated embodiment, the distributor plate is of circular configuration and is adapted to pivot about its central axis within the hopper 12 above a base plate 26 of the hopper. The opening 14 is provided in the base plate 26 of the hopper. The distributor plate may be adapted to pivot through 360°, or it may oscillate through a predetermined arc. In either case, the movement is periodic and adapted to reposition each of the feed apertures 24 so that a different feed apertures becomes aligned with the opening 14 in the base plate 26 after each movement. A suitable pneumatic actuator is provided for producing the pivoting movement of the distributor plate 22. Foam projectiles within the hopper 12 are agitated by the movement of the distributor plate 22 and randomly fall into the feed apertures 24. The projectiles can only align themselves vertically in the feed apertures 24, which may be considered to be a series of moving funnels. The distributor plate 22 need not be of circular configuration, but may, for example, be of rectangular configuration and adapted to oscillate in a linear direction.

The other, lower end of the magazine 16 is mechanically coupled to a launcher 30, which is similar to the bench mounted launcher described in co-pending Australian Provisional Application No. PQ8442, filed on 29 June 2000, the disclosure of which is incorporated herein by reference. The launcher 30 includes a rotatably mounted breech block 32 as can be seen most clearly in Figure 3. Breech block 32 is of spherical configuration and operates in a manner similar to a ball valve. Breech block 32 includes a recess 34 within which a compressible foam projectile 36 can be received. The breech block 32 is rotatable between a first position in which it receives a projectile 36 into the recess 34, and a second position (as shown in Figure 3) in which the recess communicates with an air chamber 38.

The breech block 32 has an outer wall 40 of substantially spherical configuration and is provided with an air inlet port 42 which aligns with an air supply inlet 44 when the breech block 32 is in the second position (as shown in Figure 3). However, when the breech block 32 moves back to the first position the outer spherical wall 40 seals against the air supply inlet to close off the air supply. The launcher 30 is substantially identical to the bench mounted launcher described in PQ8442, and will not be described in further detail again here.

In use, when a projectile 36 has been loaded into the recess 34, the breech block 32 is rotated to the second position and a source of compressed air is connected to the air chamber 38 and the projectile 36 is launched into the hose, pipe or tube. A nozzle 46 is fitted to the front of the air chamber 38 and is adapted to couple the air chamber to the mouth of the hose, pipe or tube (not shown). The nozzle 46 may come in various shapes and sizes depending on the inside diameter of the hose, pipe or tube and the outside diameter of the compressible foam projectiles 36.

The automatic projectile dispensing system further comprises a projectile releasing means 50 provided in connection with the magazine 16 for releasing a projectile into the recess 34 of the launcher 30. In this embodiment, the projectile releasing means 50 comprises a sleeve valve 52 which is slidable between a first position in which the bottom end of the magazine 16 is open to allow a projectile to drop into the recess of the launcher, and a second position in which the bottom of the magazine 16 is closed so that a projectile 16 is held in the bottom of the magazine ready to drop into the recess when the previous projectile has been fired. The projectile releasing means 50 further comprises a pinch cylinder 54 mounted adjacent to the magazine 16 and having a pin piston 56 that passes through an aperture provided in the side wall of the magazine 16, when in its extended position. The pinch cylinder 54 is mounted on a pivotable arm 58 to allow the height of the pinch cylinder 54 to be varied for various heights of projectiles within the magazine 16. In use, the pin piston 56 of pinch cylinder 54 holds the projectiles within the magazine 16, and only releases them at the appropriate time as will be described further below.

In the present embodiment, all of the actuators employed in the automatic projectile dispensing system are pneumatic actuators. However, it is to be understood that electrical actuators could also be employed. Logic control means in the form of pneumatic logic box 60 is provided for controlling the operation of each of the pneumatic actuators in accordance with the pre-programmed control logic. For example, the logic control box is operatively connected to the sleeve valve 52 and pinch cylinder 54 and will only operate the respective actuators to release a projectile when the recess 34 of the launcher is ready to receive another projectile. In this way, only one projectile at a time is loaded into the launcher.

The automatic projectile dispensing system 10 further comprises a projectile sensing means provided in connection with the magazine 16 for sensing when a projectile is present in the magazine. Preferably the projectile sensing means comprises a first pneumatic sensor 62 located at the upper end of the magazine 16, and a second pneumatic sensor 64 located at the lower end of the magazine. The first pneumatic sensor 62 senses when the magazine is full of projectiles, whereas the second pneumatic sensor 64 senses when a projectile is in the bottom of the magazine 16. Operation of the automatic projectile dispensing system 10 will now be described with reference to Figure 1.

Compressible foam projectiles 26 are poured into the hopper 12. The hopper 12 may need to be periodically replenished with projectiles depending on the rate at which the projectiles are being fired by the launcher. The projectiles are agitated within the hopper 12 due to the movement of the distributor plate 22 and by friction with the hopper wall. Projectiles randomly fall into the feed apertures of the distributor plate 24 as described above. When a projectile is carried by the distributor plate over the opening 14 provided in the base plate of the hopper, the projectile falls vertically into the magazine 16 and is maintained in a vertical position by the magazine. The variable aperture chute of the magazine 16 can hold a plurality of projectiles 36 therein end to end as can be seen most clearly in Figure 3. The projectile feeding mechanism continues to feed projectiles into the magazine 16 until the projectiles within the magazine reach a height at which they continuously interrupt the first (upper) pneumatic sensor 62. The logic control box 60 then deactivates the distributor plate 22 so that no further projectiles are fed into the magazine. At this stage, the breech block 32 is in the first position ready to receive a projectile within the recess 34, and the sleeve valve 52 is in the open position. Hence, the bottom-most projectile falls directly into the recess 34. When the trigger for the launcher 30 is actuated, the sleeve valve 52 closes, breech block 32 rotates to the second position and the projectile is launched down the hose, pipe or tube via the air chamber 38. At the same time, the pinch cylinder 54 releases a projectile and allows it to fall on top of the sleeve valve 52 (which is still in its closed position). When the trigger of the launcher is released, the pinch cylinder 54 engages the projectile above the one that has just been released, and which is now in the previous position of the projectile resting on top of the sleeve valve 52. The breech block 32 then rotates back to the first position, the sleeve valve 52 opens and the projectile sitting on top of the sleeve vale 52 drops into the recess 34 ready to commence the firing cycle again.

Now that a preferred embodiment of the automatic projectile dispensing system has been described in detail, it will be apparent that it provides a number of significant advantages, including the following:

(i) It reliably and relatively rapidly dispenses projectiles (less than one second per projectile), oriented in one direction only. The compressible foam projectiles are almost massless, have high friction, gather static and vary in height by up to 20%, and are thus very difficult to handle. Other systems have great difficulty in dispensing projectiles reliably and rapidly, (ii) The arrangement of the projectile releasing means and logic control means ensure that only one projectile at a time can be dispensed. Other systems suffer from the problem of dispensing more than one projectile at a time.

(iϋ) The arrangement of the logic control means and projectile sensing means ensure that the launcher cannot be fired unless it is loaded with a projectile. Prior art systems can fire when no projectile is present, ie, misfire or fire blanks. (iv) The entire system is lightweight and may be mounted on a wheeled trolley for ease of use and mobility.

Numerous variations and modifications to the dispensing system will suggest themselves to persons skilled in the mechanical arts, in addition to those already described, without departing from the basic inventive concepts. Furthermore, the projectile feeding mechanism for feeding projectiles from the hopper into the magazine 16 may also vary considerably from that described in the illustrated embodiment. All such variations and modifications are to be considered within the scope of the present invention, the nature of which is to be determined from the foregoing description.

Claims

CLAIMS:

1. An automatic pneumatic projectile dispensing system for automatically dispensing cleaning projectiles into a hose, pipe or tube, said system comprising: a hopper for receiving projectiles, said hopper having an opening adjacent a lower end of the hopper coupled to an elongate magazine, and a projectile feeding mechanism for feeding projectiles through said opening into a first longitudinal end of the magazine; a launcher having a breech block with a recess adapted to receive a projectile from a second opposite longitudinal end of the magazine, said recess being adapted to communicate with an air chamber of the launcher, and the projectile being launched into the hose, pipe or tube when a source of compressed air is connected to the air chamber; projectile releasing means associated with the magazine for releasing a projectile into the recess; and logic control means operatively connected to the projectile releasing means for activating said projectile releasing means when a projectile is not received in the recess so that, in use, only one projectile at a time is loaded into the recess.

2. A system as claimed in claim 1, wherein the system further comprises a projectile sensing means associated with the magazine for sensing when a projectile is present at said second end of the magazine, said projectile sensing means being operatively connected to the logic control means.

3. A system as claimed in claim 2, wherein said logic control means does not activate said projectile releasing means unless the projectile sensing means senses that a projectile is present at said second end of the magazine.

4. A system as claimed in claim 2 or claim 3, wherein said projectile sensing means comprises a first sensor located at said first end of the magazine and a second sensor located at said second end of the magazine, and wherein said first sensor is adapted to sense when the magazine is full of projectiles.

5. A system as claimed in any one of the preceding claims, wherein said projectile feed mechanism is operatively connected to said logic control means, wherein said projectile feeding mechanism is deactivated when the first sensor senses that the magazine is full.

6. A system as claimed in any one of the preceding claims, wherein said magazine is in the form of a variable aperture chute adapted to receive various diameter projectiles, arranged end to end.

7. A system as claimed in claim 6, wherein said variable aperture chute is provided in a substantially vertical orientation with said first end aligned with the opening at the lower end of the hopper.

8. A system as claimed in any one of the preceding claims, wherein said projectile feeding mechanism comprises a movable distributor plate having a plurality of feed apertures provided therein, each of said feed apertures being adapted to receive a single projectile therein in a predetermined orientation.

9. A system as claimed in claim 8, wherein when said projectile feeding mechanism is activated, the movable distributor plate is periodically moved so as to cause each of said feed apertures to be repositioned, so that a different feed aperture becomes aligned with said opening in the lower end of the hopper after each movement.

10. A system as claimed in claim 9, wherein when said projectile feeding mechanism is activated, the distributor plate rotates.

11. A system as claimed in claim 8 or claim 9, wherein when said feeding mechanism is activated, the distributor plate oscillates.

12. A system as claimed in any one of the preceding claims, wherein the projectile releasing means includes a pinch cylinder and a sleeve valve.