Patent Application
20080044228
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:
Referring to
The tube 11 is made of a conventional plastic mesh fabric to be permeable to the passage of water or other effluent while being able to retain the elements 12 in place. For example, the tube 11 is made as shown in
Alternatively, the tube 11′ may be made as shown in
Referring to
The ovate cross-sectional shape of the drainage element 10 is of elliptical shape as indicated in
Referring to
The exposed part-circumferential portion of the drainage element 10 facing uphill has a plurality of openings for passage of water into the interior of the drainage element 10 whereas the back portion of the exposed upper section of the drainage element 10 may have a permeability to prevent the passage of water therethrough thereby acting as a wall so that the water entering the drainage element 10 is retained therein for collection through the perforated pipe 16. In this embodiment, the tube 11 may be initially made or not with a part-circumferential longitudinal section that is non-permeable with respect to water in order to form the back portion of the exposed upper section of the drainage element 10. Alternatively, the tube 11 may be provided with an added layer of a material that is non-permeable with respect to water in order to form the back portion of the exposed upper section of the drainage element 10.
Where the drainage element 10 includes a perforated pipe 16, the water that is accumulated within the drainage element 10 enters the pipe 16 and is drawn off to a suitable site.
Alternatively, the pipe 16 may be omitted from the drainage element 10 and placed below the drainage element 10 within the trench 18. In this case, the drainage element 10 would serve to direct the water flowing down the hillside 17 into the perforated pipe 16.
Several drainage elements 10 may be interconnected along a straight line in a like trench 18 in order to collect water running down the hillside 17. Alternatively, the trench 18 may be formed in a serpentine manner so that the exposed surfaces of the drainage elements 10 are also serpentine across the hillside to provide an increased area to receive water flowing down the hillside 17.
Referring to
In this case, the effluent is able to flow out of the pipe 22 into the aggregate of the respective drainage elements 10, 20 and be dispersed through the trench 19 into the surrounding ground.
Referring to
The apparatus also employs a tying and cutting apparatus 26 at the end of the sleeve 23 for closing the tube 11 on itself.
In addition, a second sleeve 27 is spaced from the sleeve 23 to receive the forward end of a drainage element (not shown) that is being fabricated. A sensor 28 is also disposed within the second sleeve 27 at a pre-determined point for sensing the forward end of a drainage element being fabricated.
As an option, a perforated pipe feeder (not shown) may be provided for delivering a continuous length of perforated pipe within the sleeve 23. When this option is used, the loose fill elements surround the pipe in a circumferential manner and are then formed into an ovate shape or other suitable deformed shape.
The hopper (not shown) is of conventional structure to receive and deliver a flow of loose fill elements.
The blower 24 is an off-the-shelf item, for example, a Quickdraft 20 HP with Venturi that receives the loose fill elements from the hopper and blows the elements into the elongated sleeve 23. The operation of the blower 24 is such that only approximately six to eight inches of the sleeve 23 at the exit end is filled with the loose fill elements. The air that is blown into the sleeve 23 escapes through the loose fill elements and the exit end of the sleeve 23.
The sleeve 23 is of circular shape with an outside diameter, for example of 10 inches and is initially loaded with the tube 11 of a nominal 10 inch diameter and a length sufficient for the manufacture of a plurality of drainage elements. The tube 11 is bunched up on the sleeve 23 and is played off the sleeve 23 via the capstan arrangement 25 that is comprised of a pair of endless belt devices which are automatically operated in synchronism with the feed of the perforated pipe (not shown) in order to move the tube 11 off the sleeve 23.
When the apparatus is initially started, the forward end of the tube 11 is pulled off the sleeve 23 and gathered together on itself and tied or is gathered about one end of a perforated pipe (where used) and tied thereto. Thereafter, the blower 24 is actuated so that the loose fill elements are blown out of the sleeve 23 and into the space about the perforated pipe and within the tube 11. During this time, the pipe and tube 11 tied thereto advance into and through the second sleeve 27.
The sensor 28 within the second sleeve 27 is positioned at a pre-set point, for example ten feet, downstream from the exit end of the first sleeve 23. When the forward end of the drainage element being fabricated is sensed by the sensor 28, a signal is emitted to the blower 24 to stop the feeding of the loose fill elements into the sleeve 23. However, the movement of the pipe and the feeding of the tube 11 off the sleeve 23 continues for a short time sufficient to allow the rear end of the tube 11 to be tied about the pipe without interference from the loose fill elements. Alternatively, the feeding of the pipe and tube 11 may be interrupted or not during this time.
After the tube 11 has been tied to itself or to the pipe (where used) the tying and cutting apparatus 26 is actuated to sever the pipe and the tied net so as to form the rear end of a fabricated drainage element and the forward end of the next drainage element to be fabricated.
Thereafter, the blower 24 is again actuated and the process repeated.
As shown in
The rollers 29 are adjustable relative to each other to form a gap of from 2 inches to 16 inches to accommodate different sized drainage elements. In an alternative embodiment, the parallel components 29 may be in the form of two bars (not shown) that are located at the exit end of the sleeve 23 in order to deform the tubular unit being fabricated into an ovate cross-sectional shape. The bars would define a passage of approximately eight inches.
After deformation, the drainage unit is allowed to cure at an ambient temperature in order to effect expansion of the loose fill elements thereby rigidifying the drainage element in the ovate cross-sectional shape. For example, the rigidity of the drainage elements of ovate shape is characterized in that the drainage element tends not to deform under a load of 20 pounds applied coaxially of the major axis of the drainage element 10 and over a 10 square inch area of the drainage element 10 with the major axis disposed in a vertical plane, i.e. a loading of 2 psi.
Where the tube 11 is made of knitted plastic multifilaments, for example a “NET ALL” mesh material obtained from Tipper Tie, Inc. of Apex, N.C. several advantages are obtained. First, when this knitted mesh tube is taken off the sleeve 23, the tube necks down. That is, the diameter shrinks about an inch or so. After curing of the loose fill material and the consequent expansion, the knitted mesh tube is expanded to its original diameter with the tube then placing a greater radial compaction force on the loose fill material.
A second advantage is that the ties used to close the ends of the tube 11 tend not to slip from the knitted mesh.
The loose fill elements used for the drainage element or initially made from an expanded polystyrene with a density of from 0.2 to 5.0 pounds per cubic foot with a preferred range of from 0.2 to 1.0 pounds per cubic foot. In addition, the elements may be initially made with a shrinkage factor of from 3% to 30%.
The drainage element can be made of any length and cross-sectional shape and can filled with expandable loose fill elements with any shrinkage or density required. For example, the drainage element should have a length of at least five feet with a preferred length of from 10 feet to 20 feet.
Further, the sleeve 23 may have any suitable cross-sectional shape, such as an elliptical cross-sectional shape, or rectangular shape. In this case, there would be no need for the deformation components 29.
The drainage element may be used without incorporating a perforated pipe therein. Further, the drainage unit may be formed with a tube 11 that has an impermeable or solid bottom half so that the bottom half of the drainage element functions as a half-pipe in order to carry off water that may accumulate there.
The tube 11 may be customized with peripheral sections of different permeability to adapt to the use of the drainage element. For example for a drainage element to be placed on a hillside, the tube may have one quadrant that is to face uphill made with a fine mesh, as a coffee filter, to allow water to pass through while blocking sand and other similar particles from passing through. A second quadrant that is to face downhill, may be made with a larger mesh to allow water and sediment within the drainage element to pass through and a third and fourth quadrant that are to face downwardly may be made impermeable to act as a trough for water to flow off at a trailing end of the drainage element.
For ease of manufacture, the tube may be made of a mesh of uniform size and after formation of a drainage element, sections of the tube can be spray painted, or the like, to render those section impermeable. In this case, the loose fill elements that lie at the openings of the mesh in these sections would also be sprayed so that the coating of paint seals off the sprayed sections.
Due to the ovate cross-sectional shape, the drainage elements may be shipped more efficiently and stored in warehouses more efficiently because there is less wasted space between units as compared to stacks of cylindrical drainage elements.
The drainage elements are particularly useful for erosion control. As compared to cylindrical drainage units, a drainage unit of ovate cross-sectional shape presents a larger surface area for the collection of water when used with the major axis in a horizontal or substantially horizontal plane.
