Abstract:
An apparatus for the rapid loading, launching and retrieval of foam pellets for tube cleaning. The apparatus uses a block configuration to allow gravity feed and rapid firing of pellets into tubes. The apparatus includes a hopper feeder attachment, which is self-adjusting during pellet jams.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. application Ser. No. 11/214,180, filed on Aug. 30, 2005, which claims priority from PCT application Ser. No. PCT/US2004/004,793, filed Feb. 18, 2004, which in turn claims priority from U.S. provisional application Ser. Nos. 60/448,134, 60/448,135, and 60/448,136 filed on Feb. 20, 2003. The disclosures of all of the above-identified applications are hereby incorporated by reference into the present application. 
     
    
     FIELD  
       [0002]     The present invention relates to an apparatus for the cleaning of tubes. More particularly, to an attachment used in the cleaning of tubes using pellets and the retrieval and reuse thereof.  
       BACKGROUND  
       [0003]     Industry has been looking for ways to clean hydraulic tubing that can replace the current method of vapor degreasing. A vapor degreaser is a large organic solvent still on which the solvent vapor condenses and drains off the parts to be cleaned. Vapor degreaser systems are large, fixed installations that have a high purchase price and maintenance costs. Companies that use this method also must obtain a yearly operating permit for their facilities from the Clean Air Agencies because of the potential for air pollution and health risks that this cleaning method poses. Replacing these vapor degreasers with small, low-cost cleaning methods allows installations to consolidate sites and save money.  
         [0004]     One method to replace vapor degreasing is to propel a polyurethane foam pellet through the tube using compressed air. The tight fitting foam pellet scrubs the interior wall of the tube as it passes through. This is a widely used technique and there are at least three makers of pellets and pellet launching equipment worldwide. One component lacking from present day pellet cleaning systems is suitable equipment to efficiently capture and return the spent pellet to the operator so that it may be examined.  
         [0005]     The pellet system is currently used to clean tubes at a relatively high rate in close quartered work cells. Tubes are bent into a large variety of complicated shapes and lengths. Pellets must be loaded, launched/retrieved and examined with a minimum of operator movement. Equipment that requires the operator to find and retrieve the spent pellet lowers productivity. Safety and noise consideration require that the pellets be fired into a containment device and that the noise be reduced to acceptable levels.  
       SUMMARY  
       [0006]     The present system and method provides an innovative, unique and useful alternative to commercially available foam pellet launchers for tube cleaning. In one form, the present system provides a quick and efficient automatic loader and launcher for foam pellets. The system comprises foam pellets that are gravity fed through a tubular magazine into a cylindrical vertical passageway in a block. This passageway is intersected at a right angle by a cylindrical horizontal passageway about the middle of the block. Below this horizontal passageway the vertical bore has a valved port. The valve releases compressed air into the passageway on a piloted air command. Free to slide in the horizontal passageway, a cylindrical shuttle is attached at one end to a pneumatic actuator. At its opposite end is a hole slightly larger than and aligning with the vertical bore when the shuttle is extended. Also at this end, the shuttle has a pin through it that extends through slots on opposite sides of the block. The pin can contact a spring loaded release lever and rotate it about an axle through the block. The release lever straddles the block and has a projection that protrudes through a small hole intersecting the vertical passageway in the block.  
         [0007]     One aspect of the present system regards a foam pellet catcher and retriever having a transfer tube that receives the foam pellet from a cleaned tube. The transfer tube transfers the foam pellet to a chamber under air-pressure. The foam pellet remains in the chamber until the air-pressure is removed, at which time the foam pellet then exits the chamber.  
         [0008]     Another aspect of the system and method is a hopper attachment used to rapidly load pellet launchers. Additionally the attachment self-corrects jammed pellets, thus providing a savings from loss of down time and cost of recovery.  
         [0009]     Another aspect of the system and method comprises a fitting with a flexible seal opening to receive the (exit) end of the tube being cleaned, and a return tube to carry the pellet back to the operator where a receiver captures the pellet, separates it from the air stream and releases it to the operator.  
         [0010]     Each aspect of the present system and method provides an innovative, unique and useful attachment to commercially available foam pellet launchers for tube cleaning. This attachment speeds up the process for pellet retrieval and provides productivity improvements because the pellet method allows the user to go from the current batch-processing method to one-piece processing in work cells.  
         [0011]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating various preferred embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0013]      FIG. 1  shows an embodiment of the invention;  
         [0014]      FIG. 2  shows an exploded view of some of the major components of the invention;  
         [0015]      FIG. 3  shows a detailed cross-sectional view of the invention with its release lever in the locked position;  
         [0016]      FIG. 4  shows a detailed cross-sectional view of the invention with its release lever in the unlocked position;  
         [0017]      FIG. 5  shows a perspective view of an embodiment of a foam pellet catcher and retriever, according to the present invention;  
         [0018]      FIG. 6  shows a cut away of the receiver, according to one embodiment of the present invention;  
         [0019]      FIG. 7  shows a cross-sectional view of an embodiment of the retrieval chamber of  FIG. 6 ;  
         [0020]      FIG. 7   a  is a perspective/rear view of one embodiment of the foam pellet catcher and receiver;  
         [0021]      FIG. 7   b  is a side cross-sectional view taken in accordance with section line  7   b - 7   b  in  FIG. 7   a  illustrating one of the rods associated with one of the return springs being connected to the slide valve;  
         [0022]      FIG. 8  shows a cross-sectional view of an embodiment of the retrieval chamber of  FIG. 6 ;  
         [0023]      FIG. 9  shows another embodiment of a hopper/feeder;  
         [0024]      FIG. 10  shows a hopper/feeder with pellet jammed in the top of a feed tube;  
         [0025]      FIG. 10   a  is an enlarged cross-sectional side view of the piston device of  FIG. 10 ;  
         [0026]      FIG. 10   b  is an enlarged side, cross-sectional view of the upper ends of the outer and inner tubes of  FIG. 10 ;  
         [0027]      FIG. 10   c  is a view of the outer and inner tubes of  FIG. 10   b , but with the outer tube in the position it assumes when there is no pellet jammed in the inner tube; and  
         [0028]      FIG. 11  shows hopper/feeder with the pellet righted. 
     
    
     DETAILED DESCRIPTION  
       [0029]     The following description of various embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0030]     Reference will now be made in detail to one embodiment of the invention, an example of which is illustrated in the accompanying drawings. While the invention will be described in connection with a particular embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention defined in the appended claims.  
         [0031]     Referring to  FIGS. 1 and 2 , a device  100  for automatically loading and firing foam pellets comprises a block  1  that contains a cylindrical vertical passageway  11 . Foam pellets are gravity fed through a tubular magazine (shown as item  307  in  FIGS. 10 and 11 ) into the cylindrical vertical passageway  11  of the block  1 . This passageway  11  is intersected at a right angle by a cylindrical horizontal passageway  12 , about the middle of the block  1 . Below this horizontal passageway  12  the vertical passageway  11  has a valved port  10 . A valve  9  releases compressed air into the vertical passageway  11  on a piloted air command. Free to slide in the horizontal passageway  12 , a cylindrical shuttle  3  is attached at one end to a pneumatic actuator  7 . At its opposite end is a hole  13  slightly larger than and aligning with the vertical passageway  11 . The pneumatic actuator  7  is secured to the block  1  by a pair of threaded fasteners  7   a  that extend through corresponding slots  7   b  in a mounting plate  7   c , and into blind threaded holes (not shown) in the block  1 . The shuttle  3  has a pin  5  through it that extends through a bore  3   a  therein, through slots  16  on opposite sides of the block  1 , and through slots  4   a  in a spring loaded release lever  4 . This pin  5  contacts the spring loaded release lever  4  and rotates it about an axle  6  that extends through the block  1 . The release lever  4  straddles the block  1  and has a projection  17  that protrudes through a small hole  15  intersecting the vertical passageway  11  of the block  1 .  
         [0032]     Referring to  FIG. 3 , operation starts with one pellet (a) in the chamber below the air injection port  11 . The shuttle  3  is in the retracted position, the hole  13  is aligned with the vertical passageway  11 . The pin  5  on the shuttle  3  does not contact the lever  4  allowing the projection on the lever  4  to jam the lowest pellet (b), and pellet (c), above the shuttle  3  in the vertical passageway  11 . No pellets can fall through the hole  13  in the shuttle  3  to the bottom. Referring to  FIG. 4 , on triggering, the shuttle  3  is pushed into the forward position by the actuator  7 , first blocking the vertical passageway  11 . Then as it moves farther, the pin  5  pushes the release lever  4  back releasing the pellets. The pellets drop together until the lowest one (b) rests on top of the shuttle  3 . Once the shuttle  3  is fully forward, the pneumatic actuator  7  on the shuttle  3  detects this condition and opens the piloted valve  10 . The compressed air behind pellet (a) forces it through the lower block  2  that contains a cylindrical vertical passageway  18  (also shown in  FIG. 2 ) that is aligned with the vertical passageway  11  of block  1 . The lower block  2  also contains four openings  2   a  ( FIG. 2 ) located at the corners of the lower block  2  for the insertion of bolts  2   b . Attached to the lower block  2  is the lower fitting  8  that the flexible hose (not shown) is attached to, acting as the gun barrel. The pellet exits a muzzle at the other end of the hose (not shown) and is propelled through the tube being cleaned. The shuttle  3  remains in the forward position and air continues to flow as long as the trigger is held down.  
         [0033]     When the trigger is released the shuttle  3  moves rearward but before the hole  13  in it realigns with the vertical passageway  11 , the projection on the release lever  4  jams the pellet (c) immediately above the one resting on the shuttle  3 .  
         [0034]     As the shuttle  3  continues to move to the rear position, the hole  13  comes into alignment, and a single pellet (b) falls into the lower portion of the lower block  2 . The device  100  is now in the starting position again.  
         [0035]      FIGS. 5 and 6  show an embodiment of a foam pellet catcher and retriever (“FPCR”)  200 . The FPCR  200  includes a bell fitting  202 , transfer tube  203 , chamber  204  and a muffler  205 . The chamber  204  includes an input opening  206  and an output opening  207 , as shown in  FIGS. 6 and 7 . The chamber  204  is also known as a collection chamber. The muffler  205  is connected to the chamber  204  at opening  208 . A screen  208   a  is disposed in the chamber  204  to prevent a pellet from exiting through opening  208 .  
         [0036]     Referring to  FIGS. 6, 7  and  8 , a slide valve  209  is positioned within the chamber  204 . In operation, air pressure from the jet stream holds the slide valve  209  in position  1  ( FIG. 7 ). As the jet stream continues, air escapes through an opening  203  in the slide valve  209  and out the muffler  205 . The pellet is trapped in chamber  204  by way of the screen  208   a . When the air pressure is released the valve is released and moves to position  2  ( FIGS. 6 and 8 ), thus allowing the foam pellet  210  to fall through opening  207 .  
         [0037]     The collection chamber  204  is typically constructed of metal or plastic. In a preferred embodiment, the bell fitting  202  is a standard bell fitting and is connected to one end of the transfer tube  203 . The transfer tube  203  may be bent into a large variety of complicated shapes and lengths and is typically made of copper or other bendable material that can withstand high air-pressure. Typically, the bell fitting  202  has a flexible seal opening to receive the exit end of a tube being cleaned and is connected to the transfer tube by clamps; however, other types of connections may be used provided they are non-obstructive. The other end of the transfer tube  203  is connected to the input opening  206  of the chamber  204  and is connected to the transfer tube  203  by clamps; however, other types of connections may be used provided they are non-obstructive. The muffler  205  is connected to opening  208  of the chamber  204 . The muffler typically comprises a conventional pneumatic exhaust silencer. Such a silencer is commercially available from the Parker Division of Parker Hannifin Corp. However, other types of mufflers known in the art may be used. The muffler  205  may be connected to opening  208  by screwing the muffler  205  into threads in the opening  208 , by soldering the muffler  205  to the opening  208 , or by other attachment methods known in the art. The muffler  205  is used to control and reduce noise to acceptable levels for safety reasons because the present invention is used to clean tubes at a relatively high rate in close quartered work cells.  
         [0038]     Referring to  FIGS. 7, 7   a  and  8 , the construction of an embodiment of the chamber  204  is further illustrated. The chamber  204  includes an end cap  204   a  having a coaxially disposed input opening  206  that receives an end of the transfer tube  203 . The output opening  207  is formed in a portion of the chamber  204 . Within an interior of the chamber  204  resides the slide valve  209  that is able to move freely slidably within a bore  204   a  of the chamber  204 . An auxiliary port  204   b  is formed radially in line with the output opening  207 . The auxiliary port  204   b  and output opening  207  each can communicate with an interior area of the slide valve  209  depending on the position of the slide valve  209 .  
         [0039]     An additional pair of holes  204   b   1  are located on opposite sides of the input opening  206  in the end cap  204   a . Extending through each of the holes  204   b   1  is a rod  204   c . Each rod  204   c  has a coil spring  204   d  disposed over a portion of its length, such that one end of each of the coil springs  204   d  abuts an outer surface of the end cap  204   a . Opposite ends of each rod  204   c  are secured in blind openings in a surface  209   a  of the slide valve  209  such as by threaded engagement, adhesives or any other suitable coupling arrangements.  
         [0040]      FIGS. 7 and 8  further illustrate the operation of the FPCR  200 . As shown in  FIG. 7 , a spent pellet  210  enters the chamber  204  through the input opening  206 . Typically, the spent pellet  210  is a foam pellet made of polyurethane. The spent pellet  210  emerges from a cleaned tube (not shown) and is propelled into the transfer tube  203  via the bell fitting  202  under air-pressure. The spent pellet  210  is then transferred from the transfer tube  203  into the chamber  204  through the input opening  206 . In  FIG. 7 , the slide valve  209  moves to position  1  within the chamber  204  as long as there is air-pressure from the transfer tube  203 . As shown in  FIG. 7 , when the air-pressure is removed, the slide valve  209  in the chamber  204  moves to position  2  due to the biasing force provided by the springs  204   d . The spent pellet  210  then falls through the output opening  207  of the chamber  204 . The spent pellet  210  may then be examined by an operator, at which time appropriate action can be taken.  
         [0041]      FIGS. 9-11  show an embodiment of an attachment for fast loading foam pellets. This embodiment is comprised of a hopper made of a cylindrical container  300  about eight inches (20-32 mm) high with a removable top ( 302 ) secured with buckles to an outer wall  311 . There are four air inlets  303  (only one being visible in  FIGS. 9-11 ) around the periphery of a container floor  304  equally spaced close to an inside surface of the wall  311 . These direct air upward and serve to circulate the foam pellets in an interior area  301  of the container  300 . Mounted in the center of the container floor  304  is a cylinder piston device  305  having a piston  306 . The device  305  passes through a central opening in the floor  304 . A thin-walled vertical center tube  307  passes through the cylinder piston device  305  and extends into the interior area  301  of the container  300  to approximately two inches (5.08 mm) from the cover  302 . An outer tube  308 , slightly larger, is slipped over the tube  307  and is attached to the piston  306  ( FIG. 10   a ). The outer tube  308  is free to slip over the center tube  307  and is cut at a 45 degree angle at the top ( FIG. 10   b ). The tube lengths are such that when the outer tube ( 308 ) and its attached piston  306  are at the lower end of travel, the top of tube  308  is at or below the level of the top edge of tube  307  ( FIG. 10   c ).  
         [0042]     The cylinder piston device  305  in the floor  304  of the container  300  has several air ports. One set of ports  309  (only one being shown in  FIGS. 10 and 11 ) carries air from the interior of the container  300  to a space below a piston  306  within the cylinder piston device  305 . The space above the piston  306  is vented to the outside via several radial ports  310  in the cylinder piston device  305 .  
         [0043]     In operation, typically three to four hundred foam pellets are placed in the container  300  and the cover  302  is attached. Air entering the interior area  301  from the ports  303  in the floor  304  flows out through the center tube  307 . The air stream carries pellets into the center tube  307  where they pass down the tube  307  and stack up for loading into a pellet launcher. Below the container floor  304 , the center tube  307  has ventilation ports  307   a  ( FIGS. 10 and 11 ) in the tube  307  wall all along its length to allow the air to escape. Pellets will jam at the top opening if they are not oriented properly as they pass into the tube  307  ( FIG. 10 ). When a jam occurs, the tube  307  is partially blocked, causing the pressure to rise in the interior area  301  of the container  300 . This increase in pressure is communicated to the underside of the piston  306  through the set of ports  309 . This causes the piston  306  to rise, lifting the outer tube  308  and righting the jammed pellet and allowing it to pass down into tube  307 . Once air is flowing in the tube  307  again, air pressure in the ports  309  drops and the outer tube  308  falls to its resting position.  
         [0044]     The cylinder piston device  305  device serves an additional role as a pressure relief valve. If pellets are not used fast enough by the launcher, they stack up in the tube  307 . Although the tube  307  is vented, eventually the pellets will back up into the region of the tube that is inside the container  300 . When this happens, the tube  307  is again blocked and the piston  306  raises past the set of ports  310  and the air escapes.  
         [0045]     While various preferred embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the inventive concept. The examples illustrate the invention and are not intended to limit it. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.