Abstract:
A tool allowing both the inflation and deflation of air-filled bags such as dunnage bags is disclosed. The tool comprises rotatable controls to easily and safely manipulate both the flow of air into the device and the mode of operation between inflation and deflation. A venturi tube is used to draw air rapidly from a bag when the tool is deployed in deflation mode, while a radial vent system dissipates the force of the air exiting the device during deflation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority based on United States provisional patent application No. 60/511,047, filed on Oct. 14, 2003 and entitled “Inflation and Deflation Apparatus,” which is incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to an apparatus for the inflation and deflation of air-filled bags, such as the dunnage bags commonly used to cushion cargo loads in truck trailers, railroad cars, and the like. 
   Inflatable dunnage bags are a common means of cushioning loads shipped via truck trailer, railroad car, or other typical shipping container, particularly where the cargo only partially fills the container and shifting during transport might cause damage. Typical dunnage bags in use today are constructed of one or more layers of paper surrounding a plastic lining. The paper serves to protect the bags from tearing, and thus a greater number of layers may be used in applications where the risk of damage to the dunnage bag is greater. A valve for filling the dunnage bag is attached through a hole cut in the bag during manufacture. The bags are shipped flat from the manufacturer, and must be inflated by shipping personnel as containers are loaded with cargo. 
   The tools currently in use to fill dunnage bags with air are often simply converted tire inflation tools, which are attached to a hose leading from a source of compressed air. Some specialized tools are available for dunnage bag deflation,. such as taught by U.S. Pat. No. 5,437,30to Ramsey. In the use of such devices, the bag is first placed in the space that it will occupy as cargo is loaded into a container, and the inflation device is attached to the bag valve. The bag is then filled with air until an appropriate air pressure within the bag is achieved. The inflation tool may connect with the bag valve through a ball-lock quick-disconnect attachment, which may be engaged and disengaged by simply sliding a ring on the attachment point up or down. Filling is thus a relatively simple operation, requiring only a few seconds of the operator&#39;s time. 
   A significant limitation of the current inflation tools is that they present no way to rapidly deflate a dunnage bag. The valve assembly in some such bags may be unscrewed to release air pressure within the bag, but because the bags are fairly rigid (owing to the protective paper covering) they tend not collapse simply due to the equalization of air pressure inside and outside the bag. The bags cannot be quickly and conveniently reduced to a flat configuration such as they are shipped from the manufacturer. As a result, the standard industry practice is for shipping and receiving personnel to simply cut the bags with a utility knife in order to deflate them. 
   Dunnage bags are not reusable once cut, and thus they are generally considered to be a disposable commodity. Significant cost savings could be realized by the reuse of these dunnage bags. This could be rendered practical by devising a means to rapidly and easily deflate a dunnage bag without damaging the dunnage bag. The bags must be restored to the flat shape they held prior to their original use, so that they can be easily and compactly stored. 
   The prior art does include previous attempts to develop deflation tools for dunnage bags. U.S. Pat. No. 5,437,301 to Ramsey, discussed above, teaches a rotating valve actuator that selectively allows the flow of compressed air across an air passage connected to the dunnage bag in order to facilitate deflation. U.S. Pat. No. 6,053,222 to Peters teaches a dunnage bag deflation tool that uses a high-pressure air source to open the dunnage bag air-valve, thereby allowing deflation, and also suck air out of the bag by discharging the air through a venturi tube. A venturi tube in its simplest form is an air passage with a region of restricted diameter. According to the Bernoulli inverse relationship between air velocity and pressure, passage of air through the restricted region of a venturi tube creates a low-pressure region. This low-pressure region results in a suction effect that may be used to draw air out of an attached container. Peters teaches two different embodiments of the deflation device, which differ by the means through which the device may be switched from inflation to deflation mode. One device calls for the operator to simply place a thumb over the venturi tube exit, thereby blocking that means of egress for the high-pressure air and directing the high-pressure air into the bag. The other embodiment incorporates a manually set bi-stable switch set at the entrance to the venturi tube, which prevents air from ever entering the venturi tube and thus forcing high-pressure air in the direction of the dunnage bag valve. 
   U.S. Pat. No. 5,454,407 to Huza et al. teaches another apparatus to both inflate and deflate a dunnage bag. This device incorporates the venturi effect as part of an automatic pressure sensing system, but relies on hand pressure directly to the dunnage bag for deflation. Other devices to inflate and deflate different types of chambers are known in the art, such as that taught by U.S. Pat. No. 5,947,168 to Viard for inflation and deflation of an air mattress. 
   Each of these devices suffers from important limitations. While the Peters device allows for the inflation and deflation of a dunnage bag using an integrated tool, its control mechanisms are of limited practicality. The operator of such a device should ideally be able to quickly turn on and off the source of high-pressure air, and quickly adjust the mode setting of the device to either inflate or deflate a dunnage bag. Ideally, the necessary controls would be simple and easily manipulated. The use of the operator&#39;s thumb to maintain the Peters device in the inflation mode would quickly result in operator fatigue. Given the large number of cargo containers that may be loaded and unloaded in a typical shipping facility during an operator&#39;s work shift, this rudimentary control mechanism would quickly prove unworkable. The use of a switch at the entrance of the venturi tube is an improvement, but because of its design and position on the device would be prone to failure. The device does not incorporate any convenient means by which to switch on and off the flow of high-pressure air; presumably such a control must be incorporated into the hose feeding the device, or at the connection point for the hose to the high-pressure air source. Furthermore, the overall design of the device lacks any means of dissipating the flow of high-pressure air out of the venturi tube during deflation of a dunnage bag; it would result in a violent burst of air moving directly toward the operator. This situation raises significant safety concerns. Finally, the design of the device does not incorporate any convenient means of holding the device during inflation and deflation; this is an important safety concern as well, since if the valve connection should fail then the device would be propelled backward at great speed due to force of air. In this situation, the device would likely swing in an arc due to the attached (but flexible) air hose, and could strike the operator or a bystander With great force, potentially causing severe injury. 
   The limitations of the prior art are overcome by the present invention as described below. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention comprises an inflation and deflation device with a control mechanism and operational features that make it convenient, practical, and safe for use by operating personnel. The user activates and deactivates the flow of air through the device by a simple rotational or twisting motion, which opens a pathway between the air channel input and the air flow path through the main chamber of the device. The user can thus turn the device on quickly and easily, without releasing his or her grip on the device. The on/off control is independent of whether the device is operating in inflation or deflation mode. Further, switching of the device from an inflation to a deflation mode is achieved by merely twisting the end cap of the device. This mechanism results is a simple and reliable means by which the operator may change the mode of operation of the device. Air exiting the rear of the device is dissipated in a radial manner, in order to reduce the likelihood of injury to the operator due to a violent rush of air during deflation. 
   It is therefore an object of the present invention to provide for a single, integrated tool for the inflation and deflation of dunnage bags and like containers. 
   It is a further object of the present invention to provide a device for the inflation and deflation of air-filled bags with all necessary controls conveniently integrated into the device for ease of use. 
   It is also an object of the present invention to provide a device for the inflation and deflation of air-filled bags that disperses air ejected from the device during deflation mode. 
   It is also an object of the present invention to provide a device for the inflation and deflation of air-filled bags that improves on the safety of existing devices. 
   These and other features, objects and advantages of-the present invention will become better understood from a consideration of the following detailed description of the preferred embodiments and appended claims in conjunction with the drawings as described following: 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a perspective view of a preferred embodiment of the present invention. 
       FIG. 2  is an exploded perspective view of a preferred embodiment of the present invention. 
       FIG. 3  is a partial cut-away elevational view of a preferred embodiment of the present invention in the “on” configuration, cut along line “ 3 ” in  FIG. 1 . 
       FIG. 4  is a partial cut-away elevational view of a preferred embodiment of the present invention in the “off” configuration. 
       FIG. 5  is a cut-away view of the preferred embodiment of the present invention, cut along line “ 5 ” in  FIG. 3 . 
       FIG. 6  is a cut-away view of the preferred embodiment of the present invention, cut along line “ 6 ” in  FIG. 4 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1 and 2 , the major components of a preferred embodiment of the present invention may now be described. Barrel  10  comprises a tube with an open bore that is preferably integrated with barrel housing  24 . Attached to barrel  10  using set screw  22  is barrel extension  16 , also comprising an open bore. Alternatively, barrel  10  and barrel extension  16  could be manufactured as a single part. Attached to barrel extension  16  is valve connector assembly  17 . Valve connector assembly  17  is fashioned so as to provide a selectively lockable and unlockable engagement with a dunnage bag inflation valve (not shown). The valve connector assembly  17  may preferably be constructed as a ball-lock quick-disconnect valve connector as described in U.S. Pat. No. 5,437,301 to Ramsey, which is incorporated herein by reference. 
   Handle  12  is fitted to barrel housing  24  such that handle  12  fits within barrel housing  24  at its proximal end, and may rotate longitudinally within barrel housing  24 . Two set screws  20  (one of which is shown in  FIG. 1 ) are used to hold handle  12  in place within barrel housing  24 , but also allow limited axial rotation of handle  12  within barrel housing  24  in order to control air flow, as will be described in greater detail below. Connected to handle  12  is diffuser  26 , and threadably connected to diffuser  26  is cap  14 . Cap  14  and diffuser  26  preferably incorporate steeply angled threads so that cap  14  may be opened and closed with respect to the device with only limited rotation. The travel of cap  14  with respect to diffuser  26  is limited by cap screw  26 , such that it stops at the fully open position, that is, when vents  62  are fully exposed. Cap o-ring  30  is seated circumferentially around diffuser  26 , and fits snugly between handle  12  and cap  14  when cap  14  is in the closed position. Cap o-ring  30  prevents leakage of air between diffuser  26  and cap  14  when cap  14  is in the closed position. 
   Air hose connector assembly  18  is attached to barrel housing  24 , allowing air to flow from a compressed air source hose (not shown) through barrel housing air passage  32 . Air hose connector assembly  18  is comprised of air fitting  34 , which preferably includes a connector designed to fit a standard quick-disconnect female air hose connector. In the preferred embodiment, nipple  46  is attached to air fitting  34  using 45-degree elbow fitting  48 , thereby altering the angle of attachment of the air hose to the device to improve ergonomics. Alternatively, any other fitting type or angle might be selected for ease of use depending upon the desired configuration. Coupling  44  fits snugly within nipple  46 , and is biased radially downwardly away from fitting  48  and toward barrel housing  24  by spring  42 . The bias created by spring  42  causes a firm connection to maintain between coupling  44  and the exterior of the distal end of barrel housing  24 , thus ensuring a leak-free passage of air through the device as further explained below. Coupling  44  may preferably include a lip at its proximal end that stops its travel Within nipple  46 . Further in the preferred embodiment, top coupling o-ring  45  and bottom coupling o-ring  47  provide an air-tight seal between coupling  44  and the inner wall of nipple  46  and barrel housing  24 , respectively. Coupling washer  49  supports the distal end of spring  42  within fitting  48 . Air hose connector assembly  18  further preferably comprises U-shaped support cage  36 , which fits over and around air fitting  34  and is attached to barrel housing  24  using support screws  38 . U-shaped bracket  40  fits within support cage  36  and extends around air fitting  34  perpendicular to support cage  36 . 
   Fitted annularly within the bore of handle  12  is air distributor  50 . distributor o-rings  52  are placed at either end of distributor  50  to block the flow of air around either end of distributor  50  at the inner wall of the bore of handle  12 . Preferably, the proximal distributor o-ring  52  forms an air-tight seal between distributor.  50  and barrel housing  24  as well, fitting snugly within an annular groove on the outer edge of the proximal face of distributor  50 . Distributor  50  further comprises a number of distributor inlets  51 ; the preferred embodiment comprises six distributor inlets  51 , three of which are shown in  FIG. 2 , but alternative embodiments may include any number of such inlets  51 . Inlets  51  are preferably located at the edge of the base of the truncated cone formed by the inner portion of distributor  50  at its proximal end. As will be explained more fully below, air may pass through barrel housing air passage  32  through distributor inlets  51  to enter distributor  50  and thereby pass through the device. 
   Fitted at the distal end of distributor  50  and engaging with the distal distributor o-ring  52  is spacer  54 . Spacer  54  is preferably of an annular shape with a bore of uniform diameter. Fitted co-axially and distally to spacer  54  is volumizer  56 . Volumizer  56  comprises an interior of a truncated cone or frustoconical shape, the apex of the cone positioned at the proximal end of volumizer  56 . In an alternative embodiment, spacer  54  and volumizer  56  could be formed of a single integrated part. In another alternative embodiment, spacer  54  could be omitted altogether. 
   Barrel  10 , handle  12 , and cap  14  may be formed of any sufficiently strong, rigid material, the stronger plastics being the preferred material due to their light weight and relatively low manufacturing cost. Likewise, distributor  50 , spacer  54 , and volumizer  56  may also be constructed of strong, lightweight materials such as plastics. For purposes of strength, brass or other metals are used in the preferred embodiment for the construction of diffuser  26 , nipple  46 , bend fitting  48 , and air fitting  34 . The various o-rings in the preferred embodiment are of the types commonly found commercially, constructed of rubber or a like resilient material. Further in the preferred embodiment, support cage  36  is constructed of aluminum for both strength and weight savings, while bracket  40  and spring  42  are formed of steel for resiliency. 
   Referring now to  FIGS. 5 and 6 , the method of turning a preferred embodiment of the present invention “on” and “off” (that is, allowing the flow of compressed air through the device or stopping the flow of compressed air through the device) may be described. Handle  12  fits within barrel housing  24  such that it may rotate about the common central axis of those two parts. In  FIG. 6 , handle  12  is shown turned with respect to barrel housing  24  such that the device is in the “off” position. Handle  12  is rotated such that handle air passage  58  is not aligned with air hose connector assembly  18 , and thus air cannot flow from air hose connector assembly  18  (which is connected to the hose supplying high-pressure air) through handle air passage  58  into the bore of the device. 
   In  FIG. 5 , handle  12  is shown turned with respect to barrel housing  24  such that the device is in the “on” position. Handle  12  is now rotated such that handle air passage  58  is aligned with air hose connector assembly  18 , allowing air to flow from air hose connector assembly  18  through handle air passage  58  and into the bore of the device. It will be seen in both  FIGS. 5 and 6  that handle set screws  20  extend though the wall of barrel housing  24  and fit into handle slots  60 . Set screws  20  thus limit the travel of rotation of handle  12  with respect to barrel housing  24 , and provide a positive stop when the “on” position shown in  FIG. 5  is reached. In the preferred embodiment, external markings and wording. (not shown) may be used to indicate the direction of turn for handle  12  in order to reach the “on” and “off” positions, and may further be used to indicate the precise limits of rotation travel represented by these positions. It will also be seen that set screws  20  serve to hold handle  12  in place within barrel housing  24 . Although two set screws  20  are used in the preferred embodiment, alternative embodiments could well use any other number of set screws  20 . 
   Referring now to  FIGS. 3 and 4 , the method of moving the preferred embodiment of the invention between inflation mode and deflation mode may now be described. The device is shown in inflation mode in  FIG. 3 . Cap  14  is rotated along its threads to fit tightly against the dorsal end of handle  12  on diffuser  26  at cap o-ring  30 , thereby sealing vents  62  on diffuser  26  closed from the outside air. Because air cannot flow through vents  62 , compressed air entering air hose connector assembly  18  and passing into the bore of the device may instead flow in the direction of arrow A through barrel  10 , barrel extension  16 ,.through bag valve connector assembly  17 , and into a previously deflated or previously unused dunnage bag (not shown). 
     FIG. 4  depicts the preferred embodiment of the invention in deflation mode. As shown in the figure, cap  14  is open with respect to handle  12 , that is, threaded outwardly on diffuser  26  to the extent of its travel as limited by cap screw  28 , thereby allowing vents  62  on handle cap diffuser  26  to be exposed to the outside environment. Thus as air travels from the compressed air source and through air hose connector assembly  18 , it may travel in the direction of arrow B through volumizer  56 , then out vents  62  in the direction of arrows C. Because in the preferred embodiment there are numerous vents  62  spaced at intervals around the circumference of diffuser  26 , the pressurized air exiting through vents  62  is reduced in force to avoid operator injury. 
   The operation of the device to deflate dunnage bags may also be described in reference to  FIG. 4 . As previously indicated, air is forced through air hose connector assembly  18  into the device. The air enters the device bore through distributor pinholes  51 . The air is then drawn in the direction of arrow B by the reduced pressure created in distributor  50 ; the decreasing diameter of distributor  50  results in the creation of a reduced pressure region through the well-known Bernoulli principle. This reduced pressure thus draws the air through distributor  50 , spacer  54 , and volumizer  56 , and finally out of the device through vents  62 . Air from the dunnage bag is drawn in the direction of distributor  50 , passing from the dunnage bag, through bag valve connector assembly  17 , barrel extension  16 , barrel  10 , and into distributor  50 . From there the air from the dunnage bag is ejected from the device with the compressed air from air hose connector assembly  18 . Using typical compressed-air sources such as industrial-sized air compressors, the preferred embodiment of the device can reduce a standard-sized dunnage bag to a flat shape appropriate for storing and reuse in only a few seconds. 
   The present invention has been described with reference to certain preferred and alternative embodiments that are intended to be exemplary only and not limiting to the full scope of the present invention as set forth in the appended claims.