Abstract:
An apparatus and a method for removing air from a collapsible plastic structure having known characteristics of flexibility and curvature. The apparatus is a hollow cylindrical plastic tubing having interior and exterior surfaces, the interior surface defining a flow path for a fluid. The exterior surface of the tubing is formed to have a selected number of ridges defining valleys there between, the ridges extending for a selected length of tubing. A plurality of perforations are formed in the valleys, and extended a selected length of tubing for providing a plurality of additional flow paths to the interior of the tubing.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates to a suction tube to be used with a blower/fan assembly. More particularly, the present invention relates to a Suction tube adapted for use in deflating a flexible body.  
         [0003]     2. Background of the Invention  
         [0004]     Currently there exists a market of inflatable structures that may be used for a variety of applications. Exemplar of these are the inflatable trampoline, or bounce, type structures used as children&#39;s entertainment. Such structures typically consist of an inflatable base or flooring section of varying thickness, sides, which may also be inflatable, and, in some cases, a roof section. Typically 18-ounce vinyl coated fabric is used, i.e, meaning that the material weighs approximately 18 ounce per square yard of fabric. A typical bounce apparatus can have up to 300 square yards or more of fabric. The structures are usually inflated by means of a fan or blower that injects air through a vent, or valve, in the base or flooring section of the structure. When a sealed structure is inflated, the air is maintained in the structure by means of plugging the vent or capping the valve. In other similar structures, where the fabric is sewn creating seams, the needle holes made during sewing create a flow path for air to continuously escape, and when the seams are not sealed, the fan is operated continuously to keep the apparatus inflated the whole time it is in use.  
         [0005]     These structures are typically erected at playgrounds, fairs, amusement parks, and other similar venues, and are erected as temporary structures for the duration of an event. At the end of the event, the structure is deflated, packed up, and either moved to another site, or stored for use at another time. The current practice of deflating the structure consists merely of unplugging the vent, or uncapping the valve, and relying on the weight of the structure to collapse the structure under gravitational pull, and force the air from the structure through the vent. This method of deflation can be time consuming based on the size of the structure. Deflation can be speeded up by initiating the folding, or rolling up, of the structure to mechanically force the air from the structure.  
         [0006]     The present invention describes a method and apparatus for deflating such structures that significantly reduces the time for deflating and packing such structures. The means of deflating the inflatable structure includes employment of suction tubing. Prior art is replete in the use of suction tubing for a variety of applications. Prior art tubing typically is at least semi-rigid, and capable of being sealed at both ends of the tubing, without the opportunity of air intrusion into the tubing except at the distal ends, in other words, holes in the body section of the suction tubing typically results a loss of suction, or a degradation in the operation of the tubing. However, such typical suction tubing is not efficient for use in the removal of air from an inflatable flexible structure. Inflatable flexible structures are typically constructed of a vinyl material that tends to form about the intake of the suction tubing, thereby blocking, partially or completely, the flow of air from the structure. The only way to continue deflating the structure with such tubing is to continually re-position the intake of the suction tubing to another location in the structure. However, this is also time consuming, and does not result in an efficient extraction of air from the structure since it is usually necessary to remove the suction pressure from the tubing in order to relocate it within the structure.  
         [0007]     The present invention overcomes these limitations and provides an apparatus and method for efficiently deflating an inflatable structure by means of a specially formed suction tube.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention describes an apparatus and method of deflating inflatable structures. The method consists of attaching a specially designed suction tubing to a blower/fan, inserting the suction tubing in the vent, or valve of the structure, and operating the blower/fan in a manner to create suction, thereby removing the air from the structure.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a perspective view of an inflated, flexible vinyl structure showing the suction tubing of the invented inserted therein.  
         [0010]      FIG. 2  is a perspective view of the flexible vinyl structure after the air has been removed from the structure.  
         [0011]      FIG. 3  shows a perspective view of the preferred embodiment of the suction tubing of the invention.  
         [0012]      FIG. 4  shows a cross-sectional view of the tubing of  FIG. 3 .  
         [0013]      FIG. 5  shows a perspective view of the second exemplary embodiment of the suction tubing of the invention.  
         [0014]      FIG. 6  shows a cross-sectional view of the tubing of  FIG. 5 .  
         [0015]      FIG. 7  is a front cross-sectional view of means for perforating the tubing. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     Referring now to the drawings,  FIG. 1  describes a perspective, cutaway view of an inflatable structure  100 , fully inflated, with the apparatus of the invention. At the base of structure  100  is air vent  110 , for the receipt and removal of air from blower  200 . Upon inflation of the structure, escape of the air within the structure is blocked by any conventional means, not shown, known to those of ordinary skill in the art, such means comprising a plug, cap, valve, or other equivalent means. Vent means  110  of structure  100  is not an element of the invention. It is only described for the purposes of understanding the use of the invention described herein. Also shown in  FIG. 1  is suction tubing  210  extending through vent  110  and inserted a selected distance into base area  120  of structure  100 . As shown in  FIG. 1 , suction tubing is placed to extend a substantial distance across the floor of base area  120 .  
         [0017]      FIG. 2  describes a perspective view of structure  100  after deflation, with suction tubing  210  extending through vent  110 .  
         [0018]      FIG. 3  discloses a perspective view of suction tubing  210 , comprising a hollow elongated cylinder particularly adapted to convey fluids, which in this exemplary embodiment would be air, the tubing having a circular intake orifice  205 . Extending a selected length of tubing  210  are ridges  220  disposed circumferentially along the length of the tubing, said ridges creating valleys, shown as surface  30 , therebetween. Disbursed radially about tubing  210 , on surface  230 , medially between ridges  220  are perforations  240 , providing a flow path for a fluid, such as air, between surface  230  and the interior of tubing  210 . Thus, when orifice  205  is blocked, or partially blocked, the suction pressures will pull air through the perforations  240  and from structure  100 , permitting continued withdrawal of air from structure  100 .  FIG. 4  discloses a cross-sectional segment of tubing  210  providing a plan view of the ridges  220  and the surface  230  of the tubing. The selection of the distance d between ridges  220 , and the height h are important in the determining the physical parameters of tubing  210 . As can be appreciated by one of ordinary skill in the art, in addition to a proper selection of distance d, it is also important to select the appropriate thickness t and height h of ridges  220  to ensure that the material of structure  100  do not abut through holes  240  to prevent the removal of air.  
         [0019]     Referring specifically to  FIG. 4 , in this exemplary embodiment tubing  210  is comprised of an extruded, u-shaped vinyl commonly referred to as webbing, and which in this application is referred to as web  250 , having a bottom side  255  and two parallel sides  260 , which web  250  is spirally wound to form a cylinder, having tow abutting sides  255 . Cap  265  is also extruded and u-shaped, having a top side  270  and two parallel sides  275 , sized to matingly bind the two abutting sides  260  of web  250  to strengthen the cylinder, and when mated, web  250  and cap  265  combine to form tubing  210  having and interior  215  providing a flow path for a fluid. Experimentation has shown that for  18  ounce vinyls of the type used for structure  100 , an optimum distance d between ridges is about 0.155 inches, with a ridge height h of the combined sides  260  and cap  265  of about 0.25 inches. The thickness of the bottom side  255  is about 0.040 inches. The process for manufacturing the spirally formed tubing  210  is known to those of ordinary skill in the art and is not a limitation of the invention claimed herein. Further, one of ordinary skill in the art, upon selection of the different vinyl material for apparatus  100 , would know that the dimensions of d, h and t need be varied based on the flexibility and curvature characteristics of the vinyl. Thus, a more flexible vinyl may require that the distance d between adjacent ridges be less.  
         [0020]      FIG. 7  is a cross-sectional view of a typical apparatus  300  for placing perforations  240  in tubing  210 . In this preferred embodiment, the holes are punched in web  250  before the step of bindingly mating cap  265  with web  250  during the manufacturing process of tubing  210 . Apparatus  300  consists of a pair of bushings, spring retention bushing  315 , and die bushing  322 , a bias means  318 , punch  308 , and asymmetrical cam  320  mounted on shaft  321 , which shaft  321  is rotated by an electrical motor (not shown). Spring retention bushing  315  is formed to include a cylindrical cavity  319 , for receiving bias means  318  and for housing punch  308 , the cylindrical cavity  319  being symmetrical about its longitudinal axis.  
         [0021]     Punch  308  is cylindrical, having a punch die cutting edge  310  at one end and a cam-following end  312  at the distal end. Intermediate punch  308  is punch flange  309 , which functions to restrict the longitudinal travel of punch  308  in the direction of the upward arrow. Horizontally spaced between flange  309  and cam-following end  312  is spring retention flange  314 , also fixedly attached to punch  308 . Spring retention flange  314  serves to retain bias means  318  within cylindrical cavity  319 . Punch  308  is symmetrical about its longitudinal axis, and when mounted in apparatus  300 , it is in axial alignment with cylindrical cavity  319 .  
         [0022]     Die bushing  322  has a circular orifice  324  in axial alignment with the longitudinal axis of cylindrical cavity  319  and punch  308 , the circular orifice  324  sized to complementarily receive punch die cutting edge  310 . Thus the location of aperture  324  is fixed in relation to punch  308 . Die bushing  322  has upper surface  327  for receiving web  250 .  
         [0023]     When apparatus  300  is assembled, punch cam-following end  312  is positioned against the surface of cam  320 , with spring retention flange  314  maintaining bias means  3   18  within cylindrical cavity  319 . Punch die cutting edge  3   10  is positioned over circular orifice  324  of die bushing  322 , and punch flange  309  is biased against the bottom surface  305  of bushing  315  by bias means  318 . Thus, when shaft  321  is rotated, punch  308 , being biased against asymmetrical cam  320  by bias means  318 , is driven in a linear direction shown by the arrows to mate with die  322 , and thereby perforating web  250 .  
         [0024]     In this embodiment bias means  318  is a helical coil, or spring, which compresses when punch die body  309  is influenced down by cam  320 , with the forces of compression maintaining cam-following end  312  of punch  308  firmly against cam  320 . However, bias means  318  could also be a leaf spring, or other equivalent biasing means known by one of ordinary skill in the art.  
         [0025]     Perforations  240  are punched into tubing  210  at selected locations along tubing  210  in the following manner. As web  250  is indexed through apparatus  300 , punch  309  is positioned over a selected location along  250 . Cam  320  rotates about shaft  321  in a fixed relationship to the speed that web  250  is indexed through apparatus  300 . As the asymmetrical cam  320  drives punch  308  to its furthest extended linear position, punch die body  309  punches a peforation hole in web  250 . Thusly, perforations  240  are punched in tubing  210  at selected distances. Web  250  is then fed through apparatus which mates cap  265  to the abutting sides  255  of web  250 . In this manner, a channel for airflow is provided along the selected length of tubing  210  even when structure  100  collapses about tubing  210  during deflation. In this exemplary embodiment, the diameter of perforations  240  is about 0.037 inches. The method of perforating tubing  210  is not a limitation on the invention, but is described solely to show one means by which tubing  210  may be perforated.  
         [0026]      FIGS. 5 and 6  describe a second exemplary embodiment whereby the suction tubing is formed by a different process than the tubing of  FIG. 3 . Tubing  410  is produced by blow molding. Blow molding is a method of forming hollow articles out of thermoplastic materials whereby a molten tube of thermoplastic material is blown up with the use of compressed air to conform to the interior of a chilled blow mold. In this example, the interior of the chilled blow mold is made to conform with the desired shape of tubing  410 . The mold would include elements that would provide perforations in the finished tubing. Thus tubing  410  would be removed from the mold with perforation holes  440  having been formed in the mold.  FIG. 6  discloses a cross-sectional segment of tubing  410  providing a plan view of the ridges  420  and the surface  430  of the tubing with perforation holes  440 . It can be readily seen the contour of the tube of  FIG. 6  is smooth, however both the tubings of  FIG. 3  and  FIG. 5  will provide the same result as long as the dimensions of d, h and t are selected relative to the selected vinyl for apparatus  100 . The process of blow molding is well know to those of ordinary skill in the art. It should be appreciated that the mold may be constructed so that ridges  420  are spiral along the length of tubing  410 , or ridges  420  may be circumferential to the longitudinal axis of tubing  410  and parallel. It should also be apparent to one of ordinary skill in the art that the profile of the orifice of the tubing need not be circular, and that said profile may also be rectangular, the tubing then resembling a duct, having two sets of opposing, parallel sides. In such case, it may be desirable to perforate the tubing on all four sides for a selected length of the tube for the most optimum removal of air from the apparatus.  
         [0027]     It should be noted that the method of blow molding the tubing of the invention has some limitations not present in the extrusion method. In the blow molding process, the length of the tubing is restricted to the length of the mold, however, with the extrusion method, the tubing may be manufactured of any selected length.  
         [0028]     As noted above, many apparatus require that blower  200  be operated continuously due to leakage at the seams of the apparatus. When it is then desired to deflate the apparatus, it is only necessary to reverse the operation of blower  200  to suction air from the apparatus.  
         [0029]     While the present description contains much specificity, this should not be construed as limitations on the scope of the invention, but rather as exemplifications of one/some preferred embodiment/s thereof. Accordingly, the scope of the invention should not be determined by the specific embodiments illustrated herein. The full scope of the invention is further illustrated by the claims appended hereto.