Patent Publication Number: US-7913724-B2

Title: Inflation device

Description:
CROSS-REFERENCE TO PRIORITY APPLICATIONS 
     This application is a continuation of and hereby claims the benefit of the commonly assigned South African Patent Application Serial No. ZA2008/02055 (filed Mar. 4, 2008), and the commonly assigned International Patent Application No. PCT/IB2009/050851 (filed Mar. 3, 2009), both of which are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an inflation device. More particularly, the invention relates to an inflation device for inflating containers with non-rigid walls, such as dunnage bags. 
     BACKGROUND 
     Inflatable dunnage bags are commonly used for cushioning loads shipped in trucks, trailers and containers transported by ships, trucks or rail. This is often the case when the cargo only partially fills the container and there exists the possibility of shifting during transport that could cause damage. Typically known dunnage bags are constructed of one or more layers of paper or woven polypropylene surrounding a plastic lining. The paper protects the bags from tearing—thus more layers are used in applications where the risk of damage to the dunnage bag is greater. Furthermore, for inflating and deflating the dunnage bag, a valve is attached by way of a hole cut in the bag during manufacture. 
     The dunnage bags are shipped flat from the manufacturer, and are inflated by packing and loading personnel as the containers are loaded with cargo. The bag is firstly placed in the space that it will occupy as cargo is loaded into a container, secondly the inflation device is attached to a valve of the dunnage bag and subsequently the dunnage bag is filled with air until an appropriate air pressure within the bag is achieved. Typically this occurs within a few seconds. 
     Various types of inflation devices exist for inflating containers with non-rigid walls and air-filled bags, such as sacks and dunnage bags commonly used to cushion cargo loads. Known inflation devices include tire inflation tools which have been converted or adapted and are attached to a hose leading from a source of compressed air. Some inflation devices incorporate venturi tubes and are often known as venturi air-flow guns, which include a venturi tube, namely an air passage with a region of restricted diameter. In terms of Bernoulli&#39;s law (i.e. the inverse relationship between air velocity and pressure), passage of air through the restricted region of a venturi tube creates a low-pressure region resulting in a suction effect used to draw air out of an attached container. 
     Unfortunately the known type of inflation devices are difficult to operate and not flexible in operation and thus suffer from important limitations. Furthermore in practice it must be ensured that an inflated bag is fully inflated. 
     It is an object of the invention to suggest an inflation device which will assist in overcoming the aforesaid problems. 
     SUMMARY OF THE INVENTION 
     According to the invention, an inflation device for inflating containers with non-rigid walls such as bags, includes: 
     (a) a body; 
     (b)an air channel provided in the body and having opposite first and second open ends; 
     (c) a venturi tube in the body and being in communication with the first and second open ends of the air channel; 
     (d) a first inlet in the body and being in communication with the air channel and the venturi tube and being adapted to allow compressed air to enter the venturi tube via the air channel to the second open end; 
     (e) an outlet in the body and being in communication with the second open end of the air channel via the venturi tube and being adapted to allow air to exit from the venturi tube for inflating a container when joined to the outlet; 
     (f) a second inlet in the body and being in communication with the first open end of the air channel and being adapted to allow ambient air to be sucked or drawn into the venturi tube as a result of compressed air entering the air channel and passing through the venturi tube; 
     (g) a first self-closing valve located at the second inlet in the body and being adapted to close off the second inlet if air is not sucked into the air channel; and 
     (h) a sensor means associated with the body and being adapted to detect when a container, such as a bag, joined to the body has been filled to a predetermined degree and being adapted then to cause the supply of compressed air into the air channel to be interrupted. 
     Also according to the invention, an inflation device for inflating containers with non-rigid walls, includes: 
     (a) a body; 
     (b) an air channel provided in the body and having opposite first and second open ends; 
     (c) a venturi tube in the body and being in communication with the first and second open ends of the air channel; 
     (d) a first inlet in the body and being in communication with the air channel and the venturi tube and being adapted to allow compressed air to enter the venturi tube via the air channel to its second open end; 
     (e) an outlet in the body and being in communication with the second open end of the air channel via the venturi tube and being adapted to allow air to exit from the venturi tube for inflating a container when joined to the outlet; 
     (f) a second inlet in the body and being in communication with the air channel and being adapted to allow ambient air to be sucked into the venturi tube as a result of compressed air entering the air channel and passing through the venturi tube; 
     (g) a first self-closing valve located at the second inlet in the body and being adapted to close off the second inlet if air is not sucked into the air channel; 
     (h) a pressure relieve valve in the container, such as a bag, and being in communication with the air channel; and 
     (i) a sensor means associated with the body and being adapted to detect when a container, such as a bag, joined to the body has been filled to a predetermined degree and being adapted then to cause the supply of compressed air into the air channel to be interrupted. 
     Yet further according to the invention, there is provided a method of inflating containers with non-rigid walls, such as bags, including the steps of: 
     joining the outlet of an inflation device as set out herein to the inlet of a container to be inflated; 
     allowing compressed air to enter the first inlet for inflating the container; and 
     removing the container when the compressed air supply has been interrupted by the sensor means. 
     The inflation device may also be used to deflate the containers, for which purpose the device includes a deflating valve. 
     The inflation device may be a venturi-air flow apparatus or gun. 
     The venturi tube may include a supersonic nozzle. 
     In use the air exiting the outlet may have an absolute pressure of about 9 bar. 
     In use the compressed air entering the air channel may have a pressure of 9 bar absolute. 
     The supersonic nozzle may be a shock-free type. 
     The inflation device may be used as a high volume inflator operating at low pressure. For example, the inflation device may operate at a flow rate of between about 40 and 50 liters per minute. 
     In use the operating pressure of the inflation device may be about 9 bar absolute. 
     The body may have a flange for securing the inflation device to the container. 
     The container may be a dunnage bag, a sack and/or any other flexible container to be pressurized. 
     The body may include threads suitable for cooperating with complementary threads of a container&#39;s inlet. 
     The device may include a valve connector assembly attached to the outlet of the air channel, which is adapted to be releaseably engaged to a valve. 
     The venturi tube may include a frustoconical bore. 
     The first inlet may be adapted to receive an air hose for supplying compressed air. 
     The first inlet may include a second self-closing valve. 
     The second self-closing valve may be adapted to automatically close off the first inlet. 
     The first closing valve and the second closing valve may include a spring adapted to assist the valves in closing the respective openings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       The foregoing and other objects and advantages of the invention and the manner in which the same are accomplished will become clearer based on the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a side view of an inflation device in accordance with one embodiment of the invention; 
         FIG. 2  is a front view of the inflation device as seen from arrow II in  FIG. 1 ; 
         FIG. 3  is a rear view of the inflation device as seen from arrow III in  FIG. 1 ; 
         FIG. 4  is a top view of the inflation device as seen from arrow IV in  FIG. 1 ; 
         FIG. 5  is a second side view of the inflation device as seen from arrow V in  FIG. 2 ; 
         FIG. 6  is a side view of the internal components of the inflation device as shown in  FIG. 1 ; 
         FIG. 7  is a front view of the internal components of the inflation device as seen from arrow VII in  FIG. 6 ; 
         FIG. 8  is a sectional side view of the internal components of the inflation device as seen from arrows VIII-VIII in  FIG. 7 ; 
         FIG. 9  is a perspective view of the air channel of the inflation device as shown in  FIG. 1 ; 
         FIG. 10  is a side view of the air channel of the inflation device as seen from arrow X in  FIG. 9 ; and 
         FIG. 11  is a sectional side view of the air channel of the inflation device as seen from arrows XI-XI in  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION  
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     Referring to the drawings, an inflation device in accordance with the invention, generally indicated by reference numeral  10 , is shown. 
     The inflation device  10  is intended for inflating containers with non-rigid walls such as bags. 
     The inflation device  10  includes: 
     (a) a body  12 ; 
     (b) an air channel  14  provided in the body and having opposite open ends  16  and  18 ; 
     (c) a venturi tube  20  in the air channel  14  and being in communication with the first open end  16  and second open end  18  of the air channel  14 ; 
     (d) a first inlet  22  in the body  12  and being in communication with the air channel  14  and the venturi tube  20  and being adapted to allow compressed air to enter the venturi tube  20 ; 
     (e) an outlet  24  in the body  12  and being in communication with the open end  18  of the air channel  14  and being adapted to allow air to exit from the air channel  14  and venturi tube  20  for inflating a container when joined to the outlet  24 ; 
     (f) a second inlet  26  in the body  12  and being in communication with the air channel  14  and being adapted to allow ambient air to be sucked into the venturi tube  20  as a result of compressed air entering the air channel  14  and passing through the venturi tube  20 ; 
     (g)a first self-closing valve  28  located at the second inlet  26  in the body  12  and being adapted to close off the second inlet  26  if air is not sucked into the air channel  14 ; and 
     (h) a sensor means  30  associated with the body  12  and being adapted to detect when a container, such as a bag, joined to the body  12  has been filled to a predetermined degree and being adapted then to cause the supply of compressed air into the air channel  14  to be interrupted. 
     The body  12  furthermore has a handle  32  for suitably gripping and holding the inflation device  10  during filling of a bag. 
     The inflation device  10  can also be used to deflate containers by means of a deflating valve. 
     The inflation device  10  is typically in the form of a venturi-air flow apparatus or gun. 
     The venturi tube  20  includes a supersonic nozzle  34 , which is of a shock-free type. 
     In use the air exiting the outlet  24  can have an absolute pressure of about 9 bar. 
     In use the compressed air entering the air inlet  22  can have a pressure of about 9 bar absolute. 
     The outlet  24  is adapted to be releasably engaged to an inlet valve of a container to be inflated. 
     The fitting  36  connected to the first inlet  22  is adapted to be coupled to an air hose. It is also provided with a second self-closing valve. This second self-closing valve is adapted to automatically close off or seal the first inlet  22 , for example, when caused to do so by the sensor means  30 . 
     The venturi tube  20  has a first self-closing valve  28  at the second inlet  26  including a spring adapted to assist in closing the inlet  26  to the venturi tube  20 . 
     The second self-closing valve includes a spring adapted to assist in closing the first inlet  22 . 
     In one embodiment the container to be inflated can be a dunnage bag, a sack, or any number of flexible containers configured for inflation under pressure. The container is generally provided with a valve having a flange for securing the outlet  24  to the container. The valve is generally a one-way or semi-one-way valve. 
     The inflation device  10  in accordance with the invention can be used as a high volume inflator operating at low pressure for inflating containers having non-rigid walls. In one embodiment, the operating pressure of the inflation device  10  is about 9 bar absolute. 
     A pressure relieve valve is provided in the container to be inflated, such as a bag, and being in communication with the air channel. 
     The air channel  14  may also be provided with a pressure relief valve. 
     In another embodiment, the inflation device  10  in accordance with the invention, thus provides a method of inflating containers with non-rigid walls, which includes the steps of: 
     (a) coupling the fitting  36  to a compressed air supply tube; 
     (b) coupling the outlet  24  to a bag to be inflated; 
     (c) allowing compressed air to enter through a first inlet  22 ; 
     (d) allowing air to be sucked through the second inlet  26  into the venturi tube  20 , as a result of the compressed air entering the air channel  14 ; and 
     (e) removing a bag when the compressed air supply has been interrupted by the sensor means  30  on reaching a predetermined filling degree in the bag. 
     The sensor means  30  can be adjusted to cause interruption of the compressed air supply depending on the degree of inflation of the bag required, for example when the bag is full under a pressure or about 9 bar. 
     In the drawings and specification, there have been disclosed typical embodiments on the invention and, although specific terms have been employed, they have been used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.