WO1999024179A1

WO1999024179A1 - Automatic pneumatic projectile launcher

Info

Publication number: WO1999024179A1
Application number: PCT/AU1998/000903
Authority: WO
Inventors: Aaron Doyle Bean; Thomas J. HAUG
Original assignee: Compri Technic Pty. Ltd.
Priority date: 1997-11-11
Filing date: 1998-10-30
Publication date: 1999-05-20
Also published as: AUPP033197A0

Abstract

An automatic pneumatic projectile launcher (10) for automatically launching compressible cleaning projectiles (22) into a hose, pipe or tube is disclosed. The launcher (10) comprises a moveable hopper (12) having an opening (14) provided at a lower end thereof coupled to a feed tube (16). The hopper (12) is moved up and down vertically in a reciprocating motion by four double acting pneumatic rams (25), located adjacent each corner of the hopper (12). The feed tube (16) acts as a magazine for the projectiles (22), is stationary and is slidably received through the hopper base plate (18) so that it projects upwards into the hopper during a downward stroke. The shape of the feed tube (16) is selected so that projectiles (22) enter the mouth of the tube in a predetermined orientation one above the other. A self-loading mechanism (26) is operatively coupled to the feed tube (16) for loading a projectile (22) received therefrom into an air chamber (28). When a source of compressed air is connected to the air chamber (28) the projectile is launched into the hose, pipe or tube. The launcher (10) removes the need for manual loading and firing of projectiles and therefore eliminates operator fatigue.

Description

AUTOMATIC PNEUMATIC PROTECTI E LAUNCHER

FIELD OF THE INVENTION

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

BACKGROUND TO THE INVENTION

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. 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 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 tubes to clean the interior of the pipe.

In commonly assigned U.S. patent Nos. 4,974,277 and 5,329,660 two types of hand held pneumatic gun are described, each having an airway that is coupled to a source of compressed air, the airway communicating with an air chamber via a trigger valve. In each case, the gun includes a detachable breach that is supported in sealed engagement against the air chamber by a support ring pivotally secured to the body of the gun. The breach incorporates a nozzle that is secured to one end of a piece of hose or tube and a polymer projectile is placed manually into the breach to be forced by air pressure through the hose or tube to clean the interior of the hose or tube.

It is estimated that a worker using a hand held pneumatic gun can achieve a discharge rate of 200 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 before it leaves the factory. This may require up to 21,000 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 or bench mounted pneumatic guns.

SUMMARY OF THE INVENTION

The present invention was developed with a view to providing an automatic pneumatic projectile launcher which eliminates fatigue by minimising the need for manually loading the launcher and firing projectiles.

According to one aspect of the present invention there is provided an automatic pneumatic projectile launcher for automatically launching cleaning projectiles into a hose, pipe or tube, the launcher comprising:

a moveable hopper having an opening provided at a lower end thereof coupled to a feed tube, and actuating means for moving the hopper up and down in a vertical reciprocating motion wherein projectiles loaded into the hopper are gravity fed into the feed tube; and, a self-loading mechanism operatively coupled to said feed tube for loading a projectile received from the feed tube into an air chamber, wherein when a source of compressed air is connected to the air chamber the projectile is launched into the hose, pipe or tube.

Preferably said feed tube remains stationary and is slidably received through said opening so that it projects upwards into the hopper during a downwards stroke. Advantageously the shape of said feed tube is selected so that projectiles enter the tube in a predetermined orientation, one above the other.

In a preferred embodiment said actuating means comprises a plurality of pneumatic rams. Typically said hopper is substantially rectangular in shape and four pneumatic rams are provided, one adjacent each corner for moving the hopper up and down.

In one embodiment said self-loading mechanism comprises a slide having a breech block slidably mounted thereon, and actuating means for moving said breech block on said slide between a first position in which said breech block receives a projectile from said feed tube into a breech aperture, and a second position in which said breech block seals against a breech plate to form said air chamber. Advantageously said self-loading mechanism further comprises a pivoting means for pivoting said breech block through 90° as it moves between said first and second positions, wherein said breech aperture receives a projectile from said feed tube in a vertical orientation, and seals against said breech plate with the projectile in a horizontal orientation. Preferably said self-loading mechanism also includes a retaining means for retaining any further projectiles in the feed tube when said breech block moves from the first to the second position.

Preferably the automatic launcher further comprises a detachable nozzk assembly including a nozzle mounted in a sealed position against said breech plate in which the nozzle is sealed against the air chamber. Advantageously the automatic launcher further comprises a programmable controller means for controlling the operation of said moveable hopper and self- loading mechanism according to a predetermined sequence of steps.

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

Figure 1 is a side view of a preferred embodiment of the automatic projectile launcher shown in a firing position, with side panel removed;

Figure 2 is a side view of the automatic projectile launcher of Figure 1 shown in a loading position;

Figure 3 is a plan view of the automatic projectile launcher of Figure 1 with top panel and hopper removed; and,

Figures 4(a) and 4(b) are embodiments of two alternative nozzle assemblies employed in the launcher of Figures 1 to 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Figures 1 to 3 illustrate a preferred embodiment of an automatic pneumatic projectile launcher 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 high density foamed plastics material, examples of which are described in commonly assigned U.S. patent No. 5,555,585 and pending application No. U.S.S.N. 08/714,541. The launcher 10 comprises a moveable hopper 12 having an opening 14 provided at a lower end thereof coupled to a feed tube 16. The opening 14 is provided in a hopper base plate 18 which is mounted on a frustum shaped base section 20 of the hopper 12. The hopper 12 is moved up and down vertically in a reciprocating motion by an actuating means in the form of four double acting pneumatic rams 25, located adjacent each corner of the hopper 12. Pneumatic and electric control lines have been omitted from the drawings for clarity. Typically single movement cycle of hopper 12 includes a downward stroke followed immediately with an upward stroke.

The feed tube 16 acts as a magazine for the projectiles 22 and in this embodiment remains stationary and is slidably received through the hopper base plate 18 so that it projects upwards into the hopper during a downward stroke as shown in Figure 1. In Figure 1 the hopper 12 is shown in its lowermost position whereas in Figure 2 the hopper 12 is shown in its uppermost position. The shape of the feed tube 16 is selected so that projectiles 22 enter the mouth of the tube in a predetermined orientation one above the other as can be seen most clearly in Figure 1. Typically, the tube 16 is of cylindrical configuration with a diameter selected so that the projectiles 22 are fed into the tube 16 in a vertical orientation, ie, with a circular endface abutting a corresponding end face of an adjacent projectile.

Preferably, when the hopper 12 is in its uppermost position as shown in Figure 2, the hopper base plate 18 is at substantially the same height as a mouth 24 of the feed tube 16. Hence, some of the projectiles in the base section 20 of the hopper 12 will reposition themselves over the location of the opening 14 in the base plate 18 so that when the hopper 12 commences its next downward stroke and tube 16 is forced upwards through the body of projectiles within the hopper there is a high probability that at least one of the projectiles will enter the mouth 24 of tube 16. In this way, the supply of projectiles 22 within the magazine tube 16 is constantly replenished while the automatic launcher 10 is in operation. The feed tube 16 is mounted on a magazine base plate 25 as can be seen most clearly in Figure 2. The automatic launcher 10 further comprises a self-loading mechanism 26 operatively coupled to the feed tube 16 for loading a projectile 22 received from the feed tube into an air chamber 28. When a source of compressed air is connected to the air chamber 28 the projectile is launched into the hose, pipe or tube. In this embodiment the self-loading mechanism 26 comprises a breech block 30 which is slidably mounted on a slide 32, and actuating means in the form of a pneumatic ram 34 for moving the breech block 30 between a first (loading) position in which the breech block receives a projectile 22 from the feed tube 16 into a breech aperture 36, and a second (firing) position in which the breech block 30 seals against a breech plate 38 to form the air chamber 28. In Figure 2 the breech block 30 is shown in the first (loading) position directly below the feed tube 16, whereas in Figure 1 the breech block 30 is shown in the second (firing) position sealed against the breech plate 38.

In the first position of breech block 30, the feed aperture 36 is aligned with the bottom of the feed tube 16 so that the lowermost projectile 22 within feed tube 16 is gravity fed into the breech aperture 36 in a vertical orientation. As the pneumatic ram 34 moves the breech block 30 to the second position, pivoting means are provided within the self-loading mechanism 26 for pivoting the breech block through 90° as shown in Figure 1. In the illustrated embodiment the pivoting means for pivoting the breech block comprises a shaped track 39 which acts as a cam and which determines the motion of a follower wheel 40 which is rotatably mounted on a support arm 42 affixed to the breech block 30.

As can be seen most clearly in Figures 1 and 2, as the breech block 30 moves forward under the action of pneumatic ram 34, the follower wheel 40 rolls along the cam track 39 and is eventually forced to move upwards causing the breech block 30 to pivot through 90° in an anti-clockwise direction (as viewed in Figure 1) as the follower wheel traverses the diagonal portion of the cam track 39. When breech block 30 reaches the second position the breech aperture 36 is sealed against the breech plate by means of an O ring (not visible) to form the air chamber 28 as noted above. A source of compressed air is connected to the breech block by means of a pneumatic line 44 (visible in Figure 3). The supply of compressed air through line 44 is controlled by the operator by means of a foot peddle 45 (not shown). The self-loading mechanism of this embodiment also includes a retaining plate 46 for retaining any further projectiles remaining in the feed tube 16 when the breech block 30 moves from the first position to the second position. The retaining plate 46 is also mounted on slide 32 and is designed to cover the bottom end of the magazine tube 16 the moment breech block 30 has moved away from this position. The retaining plate 46 is automatically retracted when the breech block 30 returns to the first position to receive a new projectile from the magazine tube 16.

The automatic projectile launcher of this embodiment further comprises a detachable nozzle assembly 50 which includes a nozzle 52 mounted in a sealed position against the breech plate 38. A variety of sizes and shapes of nozzle 52 can be mounted in the nozzle assembly in order to accommodate various sized projectiles and various types of hose and tube connectors. Provision has also been made to add a solvent adaptor to the nozzle assembly 50 by sandwiching a solvent nozzle plate 54 between the nozzle 52 and the breech plate 38 as shown in Figures 4(a) and 4(b). The solvent adaptor allows liquid solvent to be injected into the projectile within the air chamber 28 prior to firing through nozzle 52. It has been found in practice that the addition of solvent to the projectile can greatly enhance the cleaning effect in certain types of hose and pipe. The solvent adaptor also allows solvent to be injected as an atomised vapour directly down the hose, pipe or tube to be cleaned prior to firing the projectile. Different industries have different standards of cleanliness. For example, hose, tube or pipe used in the Aircraft industry must meet Aerospace Standards, which are generally higher than in other industries. The use of a solvent can satisfy standards of cleanliness which cannot be met using projectiles alone.

The bolts holding the breech plate 38 to the front end of the launcher 10 are designed to be removed and replaced with longer bolts 56 having coil springs 58 provided in connection therewith to allow the nozzle assembly 50 to extend and match up with a tube or hose connected through an automatic part handling system as shown in Figure 4(a).

The automatic launcher 10 also includes a programmable controller typically in the form of a programmable logic controller (PLC) 60 of the kind produced by Allen Bradley for controlling the operation of the moveable hopper 12 and the self-loading mechanism 26 according to a predetermined sequence of steps. Thus, for example, the controller 60 controls the operation of the pneumatic rams 25 which move the hopper 12 up and down as required to keep the magazine tube 16 filled with projectiles. The timing of the reciprocating movement of hopper 12 is controlled in accordance with the frequency of firing of projectiles from the launcher. Likewise, the movement of the breech block 30 on slide 32 is controlled by the controller 60 in order to load a fresh projectile into the air chamber 28 ready for firing. An operator only has to place the end of a hose or pipe against the nozzle 52 and step on the foot peddle (not shown) to launch the projectile into the hose or tube. When the operator steps on the foot peddle, the controller 60 checks that adequate air pressure is available for launching the projectile, ensures that a projectile is present within the air chamber 28 and that all other mechanical components are in their correct position. Once these checks have been completed, a valve opens to connect the source of compressed air to air chamber 28 and the projectile is launched through the nozzle 52 into the hose or tube. Immediately following firing, the breech block 30 is automatically retuned to the first position for reloading of a projectile into the breech aperture from the magazine tube 16.

From the above description of a preferred embodiment of the automatic projectile launcher in accordance with the present invention, it will be evident that the launcher has significant advantages over the currently employed manual methods of firing projectiles through hoses, pipes and tubes, including but not limited to the following advantages: (a) Being fully automated, the launcher eliminates the manual loading and firing of projectiles. This results in a discharge rate of up to 3,600 shots per hour.

(b) It eliminates operator fatigue and minimises the manual labour required.

(c) Additional projectiles can be fed into the hopper at any time to replenish the supply of projectiles to the launcher.

(d) The launcher is of compact size and is readily portable.

Now that a preferred embodiment of the automatic launcher has been described in detail, it will be apparent to persons skilled in the mechanical arts that numerous variations and modifications may be made, in addition to those already described, without departing from the basic inventive concepts. For example, the manner in which the self-loading mechanism receives projectiles from the magazine and loads them into the air chamber ready for filing may vary considerably from that shown 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 and the appended claims.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. An automatic pneumatic projectile launcher for automatically launching cleaning projectiles into a hose, pipe or tube, the launcher comprising:

a moveable hopper having an opening provided at a lower end thereof coupled to a feed tube, and actuating means for moving the hopper up and down in a vertical reciprocating motion wherein projectiles loaded into the hopper are gravity fed into the feed tube; and,

a self-loading mechanism operatively coupled to said feed tube for loading a projectile received from the feed tube into an air chamber, wherein when a source of compressed air is connected to the air chamber the projectile is launched into the hose, pipe or tube.

2. An automatic pneumatic projectile launcher as defined in claim 1, wherein said feed tube remains stationary and is slidably received through said opening so that it projects upwards into the hopper during a downwards stroke.

3. An automatic pneumatic projectile launcher as defined in claim 2, wherein the shape of said feed tube is selected so that projectiles enter the tube in a predetermined orientation, one above the other.

4. An automatic pneumatic projectile launcher as defined in claim 3, wherein said feed tube is of cylindrical configuration with a diameter selected so that the projectiles are fed into the tube in a vertical orientation, with a circular end face of each projectile abutting an end face of an adjacent projectile.

5. An automatic pneumatic projectile launcher as defined in claim 1, wherein said actuating means comprises a plurality of pneumatic rams.

6. An automatic pneumatic projectile launcher as defined in claim 5, wherein said hopper is substantially rectangular in shape and four pneumatic rams are provided, one adjacent each corner for moving the hopper up and down.

7. An automatic pneumatic projectile launcher as defined in claim 1, wherein said self-loading mechanism comprises a slide having a breech block slidably mounted thereon, and actuating means for moving said breech block on said slide between a first position in which said breech block receives a projectile from said feed tube into a breech aperture, and a second position in which said breech block seals against a breech plate to form said air chamber.

8. An automatic pneumatic projectile launcher as defined in claim 7, wherein said self-loading mechanism further comprises a pivoting means for pivoting said breech block through 90┬░ as it moves between said first and second positions, wherein said breech aperture receives a projectile from said feed tube in a vertical orientation, and seals against said breech plate with the projectile in a horizontal orientation.

9. An automatic pneumatic projectile launcher as defined in claim 8, wherein said self-loading mechanism also includes a retaining means for retaining any further projectiles in the feed tube when said breech block moves from the first to the second position.

10. An automatic pneumatic projectile launcher as defined in claim 7, wherein the automatic launcher further comprises a detachable nozzle assembly including a nozzle mounted in a sealed position against said breech plate in which the nozzle is sealed against the air chamber.

11. An automatic pneumatic projectile launcher as defined in claim i, wherein the automatic launcher further comprises a programmable controller means for controlling the operation of said moveable hopper and self-loading mechanism according to a predetermined sequence of steps.