Patent Publication Number: US-2011061226-A1

Title: Machine for making preassembled drainage units

Description:
This application claims the benefit of Provisional Patent Application 61/276,773 filed Sep. 16, 2009. 
    
    
     The invention relates to improvements in the manufacture of preassembled drainage units and, particularly, drainage units as described in Published Application US2009/0123232 dated May 14, 2009. 
     As is known, machines for making preassembled drainage units employing light weigh synthetic aggregate generally comprises a chute or barrel for pneumatically blowing a flow of the aggregate into a sleeve of material disposed about the chute or barrel and with a closed end extending from the terminal end of the chute or barrel. In some cases, the sleeve is made of netting while in other cases, the sleeve is made of a geotextile material, such as, a spun bonded non-woven polyester. 
     During operation of the machines, the sleeve of material is gathered and secured outside the barrel so that upon blowing of the aggregate from the barrel, the aggregate fills the sleeve and pulls the sleeve from the barrel. After a predetermined length of filled sleeve has been blown or pulled off the barrel, continued delivery of the aggregate is stopped and a back end of the sleeve of material is gathered and secured outside the barrel. Thus is formed a preassembled drainage unit and the beginning of a second drainage unit. 
     It has been found that when the barrel is in a horizontal plane and the sleeves of the drainage units are made with sections of netting and geotextile material, a problem arises in that the drainage units do not fill uniformly to the predetermined length. For example, where the length of a drainage unit is to be 10 feet, these composite drainage units have lengths that vary from 9 feet 8 inches to 10 feet 2 inches. 
     It has also been found that there is a risk of a blowback of aggregate between the sleeve and barrel during the formation of preassembled drainage units in a machine employing a barrel for pneumatically blowing a flow of the aggregate into the sleeve. 
     Accordingly, it is an object of the invention to fill a preassembled drainage unit made with a sleeve of netting and geotextile material in an accurate manner. 
     It is another object of the invention to avoid any blowback of aggregate between a sleeve and a barrel in a machine employing a barrel for pneumatically blowing a flow of the aggregate into the sleeve. 
     It is another object of the invention to be able to form multiple preassembled drainage units of accurate lengths in a repeatable manner. 
     Briefly, the invention is directed to a machine for making preassembled drainage units that are formed of a mass of discrete lightweight synthetic aggregate within a sleeve having sections of disparate material, such as, a sleeve having a first peripheral portion of a water permeable filter material, such as a geotextile material, and a second peripheral portion of net material having openings for retaining the aggregate and allowing the passage of water. 
     The machine employs a horizontally disposed barrel over which the sleeve passes and through which a light weight synthetic aggregate-laden air stream passes. In accordance with the invention, the barrel is characterized in having a tongue that extends longitudinally from a terminal end of the barrel and that is of a complementary shape to the barrel to extend over at least a portion of the periphery of the barrel. Where the barrel is cylindrical, the tongue has an arcuate shape. 
     During operation of the machine, a light weight synthetic aggregate-laden air stream is passed through the barrel and out the terminal end of the barrel into a sleeve of the disparate materials. Generally, the air passing from the barrel is blocked from entering the aggregate filled part of the sleeve by the aggregate and, instead, deflects to move transversely through the sleeve within a gap that develops between the terminal end of the barrel and the aggregate filled part of the sleeve. Because one peripheral portion of the sleeve is made of a material having a different porosity than another peripheral portion, the flow of air through each peripheral portion is different. For example, where the peripheral portion is made of net material, the flow of air is substantially unimpeded. However, where the peripheral portion is made of water permeable filter material, the flow of air is impeded and slowed. The resulting imbalance in the air flow exiting from the barrel and through the sleeve causes a variance in the amount of aggregate delivered into a sleeve. For example, for a nominal  10  foot preassembled drainage unit, the drainage unit may have a length that varies from 9 feet 8 inches to 10 feet 2 inches. 
     Positioning the tongue so that the peripheral portion of the sleeve having the higher porosity, i.e. the net material, moves over the tongue, restricts the air from exiting transversely through the net material and past the tongue. 
     It has been discovered that by adding a tongue to the end of the barrel on the side of the netting to restrict the air flow through the aggregate and the netting, the filling of the composite sleeve becomes uniform and accurate. The addition of the tongue is believed to restrict the air flow from the barrel through the netting to the amount of air flow from the barrel through the geotextile material thereby balancing the air flow from the barrel and creating a uniform filling of the composite sleeve with aggregate. 
     The tongue may be adjustable relative to the barrel and may be provided with holes or slits to regulate the air escaping through the netting to equal the air escaping through the geotextile material. 
     In order to avoid a blowback of aggregate between the sleeve and barrel during the formation of preassembled drainage units, the invention also provides the machine with a ring that is disposed concentrically of the terminal end of the barrel to define a gap therebetween for passage of a moving sleeve of material therethrough during passage of the light weight synthetic aggregate-laden air stream from the barrel. This ring may be used with or without the tongue. In addition, the ring is hollow and has a plurality of circumferentially disposed ports directed towards the terminal end of the barrel and a supply of air is delivered to the ring for passage through the ports. 
     During operation of the machine, the ring confines the size of the annular space formed between the barrel and the sleeve at the terminal end of the barrel. In addition, a flow of air is delivered to the ring for passage out of the ports and towards the terminal end of the barrel. In this respect, the flows of air from the ports gently press the sleeve radially inwardly toward and against the barrel to block any blowback of aggregate between the sleeve and barrel. 
    
    
     
       These and other objects and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings wherein: 
         FIG. 1  illustrates a perspective view of a terminal end of a barrel in accordance with the invention; 
         FIG. 2  illustrates a part cross-sectional view of the barrel of  FIG. 1  during use in a machine for making preassembled drainage units; 
         FIG. 3  illustrates a part cross-sectional view of a ring disposed concentrically of the end of a barrel to supply a flow of air onto a sleeve moving off the end of the barrel in accordance with the invention; and 
         FIG. 4  illustrates an end view of the structures of  FIG. 3 . 
     
    
    
     Referring to  FIGS. 1 and 2 , the barrel  10  forms an end of a machine for making preassembled drainage line units, such as described in published US 2007/0081859 and 2009/0123232, and is disposed in a horizontal plane. The machine includes means (not shown) about the barrel  10  for shaping at least two continuously supplied strips of material into a tubular shape about the barrel  10  with the longitudinal edges thereof in overlapping relation; and means to seal the longitudinal edges of the material strips together to form a tube. 
     By way of example, the barrel  10  has a 10 inch outside diameter for making drainage units of 10 inch diameter. Any other diameter of the barrel  10  is also suitable. In addition, the barrel  10  may be oval in cross-section to form preassembled drainage line units of oval cross-sectional shape. 
     The drainage units are made with a composite sleeve or tube  11  made from disparate materials, such as, a strip of netting  12  and a strip of geotextile material  13 . In the example, one half of the composite sleeve  11  is made of netting and one half is made of geotextile material. However, the composite sleeve  11  may be made with sections of netting and sections of geotextile material of different proportions and positioning. 
     A tongue  14  extends longitudinally from a terminal end of the barrel  10  and is of a complementary shape to the barrel  10  to extend over at least a portion of the periphery of the barrel  10 . For example, the tongue  14  may be integral with the remainder of the barrel  10 . In this case, the end of the barrel may be cut to form the tongue  14  or a separate element may be welded to the barrel  10  to form the tongue  14 . 
     The use of a separate element to form the tongue not only allows the peripheral extent of the tongue to be adjusted relative to the diameter of the barrel  10  but also allows the longitudinal length of the tongue to be adapted to the drainage units being made. 
     Alternatively, the tongue  14  may be a separate element that is mounted on the barrel  10  in an adjustable manner so as to be moved backwards or forwards relative to the terminal end of the barrel  10 . 
     The tongue  14  has an arcuate shape to extend over 180° of the circumference of the barrel  10 . In this respect, the circumferential extent of the tongue  14  relative to the barrel  10  is equal to the circumferential extent of the strip of netting  12 . 
     The tongue  14  may be provided with holes or slits  15 , as shown in  FIG. 1 , to regulate the air escaping through the netting  12  to equal the air escaping through the geotextile material  13 . 
     During operation of the machine, a light weight synthetic aggregate-laden air stream is passed through the barrel  10  and out the terminal end of the barrel  10  into the sleeve  11  of disparate materials. Generally, the air passing from the barrel  10  is blocked from entering the aggregate filled part of the sleeve  11  by the aggregate  16  and, instead, deflects to move transversely through sleeve  11  within a gap that develops between the terminal end of the barrel  10  and the aggregate filled part of the sleeve  11 . Because the peripheral portion  12  of the sleeve  11  is made of a netting material having a higher porosity than the other peripheral portion  13  made of geotextile material, the flow of air through each peripheral portion is different. For example, the flow of air is substantially unimpeded through the netting  12  while being is impeded and slowed through the geotextile material. 
     Positioning the tongue  14  so that the net material  12  moves over the tongue  14 , restricts the air from exiting transversely through the net material  12  and past the tongue  14 . As a result, the filling of the composite sleeve  11  becomes uniform and accurate. 
     Referring to  FIGS. 3 and 4 , the machine for making a preassembled drainage unit comprised of a sleeve  11 , light weight synthetic aggregate  16  and an elongated element  17 , such as a rope, as shown, or a corrugated perforated pipe or other elongated element as described in U.S. Pat. No. 7,600,308 is provided with a barrel  18  that may or may not have a tongue as described above. As illustrated, the barrel  18  is horizontally disposed so that the aggregate  16  is blown horizontally out of the terminal end of the barrel  18  to fill the sleeve  11 . The sleeve  11  need not be made from disparate materials, as above, but may also be made solely of netting or solely of geotextile material. 
     In this embodiment, In order to avoid a blowback of aggregate  16  between the sleeve  11  and the barrel  18  during the formation of the preassembled drainage units, a ring  19  is disposed concentrically of the terminal end of the barrel  18  to define a gap therebetween for passage of the moving sleeve  11  therethrough during passage of the light weight synthetic aggregate  16  from the barrel  18 . Where the barrel has a predetermined diameter at the terminal end, the gap between the barrel  18  and the ring  19  is annular. 
     As indicated in  FIG. 3 , the ring  19  is hollow and has a plurality of circumferentially disposed ports  20  directed towards the terminal end of the barrel  18 , for example, at a slight angle from a perpendicular to the barrel  18 . During operation, a supply of air is delivered to the ring  19  from a suitable source for distribution through the ports  20  in the form of individual jets of air  21 , each of which is directed in the direction of movement of the sleeve  11  and against the terminal end of the barrel  18 . 
     During operation of the machine, the ring  19  confines the size of the annular space formed between the sleeve  11  and the terminal end of the barrel  18 . In addition, the jets of air  21  from the ports  20  gently press the sleeve  11  radially inwardly toward and against the barrel  19  to block any blowback of aggregate  16  between the sleeve  11  and barrel  19 . 
     The invention thus provides a machine for filling a preassembled drainage unit made with a sleeve of netting and geotextile material in an accurate manner and for forming multiple preassembled drainage units of accurate lengths in a repeatable manner. 
     The invention also provides a technique for avoiding any blowback of aggregate between a sleeve and a barrel in a machine employing a barrel for pneumatically blowing a flow of the aggregate into the sleeve.