Abstract:
The present invention relates generally to desiccant bags and filters for use in receiver/dryers or accumulator canisters of automotive air conditioning systems. More specifically, the present invention relates to a dual or single desiccant bag provided with a filter section such that the desiccant bag effectively combines two separate components, a desiccant bag and a filter, into a single article. Accordingly, the bag is adapted to contain adsorbent material therein to adsorb moisture, or undesirable substances, within the a/c systems of automobiles, trucks or other motor vehicles while the filter is adapted to keep particles, dirt, or dust from entering the orifice in the bight of a U-bend tube where oil pickup is provided for lubrication of the a/c system.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The benefit of prior U.S. Provisional Application No. 60/204,453 filed May 16, 2000 is hereby claimed. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to desiccant bags and filters for use in receiver/dryers or accumulator canisters of automotive air conditioning systems. More specifically, it relates to a desiccant bag provided with a filter section, and method of making same, such that the desiccant bag effectively combines two separate components, a desiccant bag and a filter, into a single article. 
     BACKGROUND OF THE INVENTION 
     Accumulators and receiver dryers in automotive air conditioning systems utilize desiccant to adsorb moisture, or undesirable substances, which can enter the system through fittings, hoses, connections, and the like. One common method of containing desiccant within the system is in a bag made of porous fabric which is retained in a fixed position within an accumulator or receiver/dryer canister. These canisters also commonly contain a U-bend tube, or pipe, with an orifice in the outside bend at the bottom of the canister to provide oil pickup for lubrication of the system. This orifice typically is covered with a filter device, made of plastic, steel, or aluminum, to assure that particles, dirt, or dust is not circulated into the a/c system. 
     Accordingly, the present invention integrates a desiccant bag and a filter into a single article such that bag is provided with a filter section. This bag and filter combination is positioned at the bottom of the U-bend tube so that the filter section covers the orifice in the outside bend. 
     One significant advantage of the invention is cost reduction insofar as the need for a separate filter assembly and a separate operation to attach the assembly to the tube is eliminated. Also, the bag can be fitted tightly around the tube thereby eliminating the possibility of any large particles entering the orifice in the U-bend tube. 
     Accordingly, the invention provides a simple way for combining a desiccant bag and a filter while at the same time reducing the material and assembly costs associated with separate components. Also, the desiccant bag keeps large particles from entering the orifice in the U-bend tube. 
     SUMMARY OF THE INVENTION 
     The present invention includes a desiccant bag made from a sheet of porous fabric. The bag comprises a filter section having a yoke, or wall portion, disposed about a central axis to define a sleeve. The bag further includes first and second longitudinal end portions having opposing top and bottom layers comprising a length and a width and having opposing sides connecting the layers. The layers further have opposing first and second ends. The second ends of the layers of the first end portion and the second ends of the layers of the second end portion are connected to form sealed ends while the first ends opposingly and integrally join the end portions with the wall portion so that the first ends run parallel with the central axis and the end portions extend outwardly therefrom. 
     Additionally, the bag comprises a seam extending across the bag for sealing lengthwise and has first and second seals. The first seal seals together the first ends of the layers of the first end portion across the width thereof adjacent the wall portion and the second seal seals together the first ends of the layers of the second end portion across the width thereof adjacent the wall portion so that the end portions define first and second compartments wherein the first seal and sealed end of the first end portion define opposing ends of a first compartment, and the second seal and sealed end of the second end portion define opposing ends of a second compartment. The first and second compartments are provided with a plurality of desiccant particles contained therein. 
     Construction of the bag involves providing a sheet of porous fabric having opposing longitudinal and lateral side edges and connecting the opposing longitudinal side edges, such as by ultrasonic, heat fusion and/or stitching procedures, to form a tube-like structure comprising a width and having opposing top and bottom layers, opposing sides for connecting the layers, and opposing first and second ends having openings. Next, spaced first and second seals are placed intermediate the ends of the tube-like structure. The seals seal across the width of the tube-like structure connecting the top layer with the bottom layer so that the ends define a compartment provided with an opening. 
     The opposing longitudinal edges of the tube between the first and second seals then are sliced lengthwise using a cutting tool or die to form the filter section having a wall portion, or yoke, disposed about a central axis and having first and second openings to define a sleeve. Lastly, the compartments are filled with desiccant and the openings sealed shut so that the ends form sealed ends for containing particles within the compartments. 
     Accordingly, the filter section receives the end of a U tube through its sleeve and the bag is easily slid thereon until the filter section is situated over an orifice in the bight of a U-bend tube. The bag fits around the U tube so that the filter section can act as a filtering device at the orifice while gravity firmly holds the bag in the canister thereby acting as a method to hold the bag in place. The yoke can be adjusted to fit tightly over the U-bend tube once assembled. 
     In an alternate embodiment, the desiccant bag comprises only one compartment for containing desiccant particles therein. In this embodiment, a first seal is placed between the ends of the tube-like structure substantially adjacent one opening. A second seal seals this opening. Both seals seal across the width of the tube-like structure and connect the top layer with the bottom layer. The single end portion defines a compartment having an opening. The opposing longitudinal sides of the tube-like structure between the seals are sliced lengthwise using a cutting tool or die to form the filter section. Lastly, the compartment is filled with desiccant and sealed shut so that the end forms a sealed end for containing desiccant particles within the compartment. 
     Notably, one can integrate different filter material into the wall portion of the bag thereby allowing for different filter characteristics as required by the manufacturer of the accumulator or receiver/dryer canister. As such, if the porous bag material is thought to be too dense to allow for proper lubricant pickup, then a more course filter material may be used in the wall portion at the location where the bag will position over the orifice. 
     Yet, a further embodiment of the invention involves providing an aperture in the filter section between the first and second openings of the sleeve so that the aperture can be positioned around a separate filter which may already be assembled on the tube. As such, the bag will still be located in place but will not act as a filter. 
     Therefore, it may be appreciated that an object of the present invention is to provide a single or dual desiccant bag having a filter integrated therein for reducing the material and assembly costs associated with separate components. 
     It is a further object of present invention to provide both a dual and single compartment desiccant bag having an aperture adapted for receiving a filter on a U-bend tube. 
     Lastly, it is another object of the invention to provide a desiccant bag with filter integrated therein that fits snugly around the bight in a U-bend tube and keeps large particles from entering the orifice. 
     Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a dual desiccant bag with integrated filter in accordance with the invention. 
     FIG. 2 is the top view of a dual desiccant bag in accordance with the invention as it is snugly and slidingly fitted over the upstanding legs of a U-bend tube. 
     FIG. 3 is a schematic view showing positioning of the dual desiccant bag in accordance with the invention over the orifice in the U-bend tube shown in FIG. 2; 
     FIG. 4 is a side elevational view of another embodiment of the invention in which the dual desiccant bag is provided with an aperture therein in the filtering section so as to receive a filter from the bight portion of the U-bend tube; 
     FIG. 5 is a top perspective view of a sheet of porous non-woven fabric used to manufacture the dual and single desiccant bags of the invention as shown in FIGS.  1  and 
     FIG. 6 is a bottom perspective view of the tube-like structure formed by connecting the longitudinal edges of the sheet from FIG. 5; 
     FIG. 7 is a bottom perspective view of FIG. 6 after spaced first and second seals are placed intermediate the ends of the tube-like structure and the longitudinal sides of the structure are cut between the seals; 
     FIG. 8 is a bottom perspective view of the tube-like structure from FIG. 7 wherein the compartments have been sealed to form end seals thereby forming a dual desiccant bag of the present invention having a filter section integrated therein; 
     FIG. 9 is a perspective view of another embodiment showing a single desiccant bag with integrated tube filter; 
     FIG. 10 is a schematic view of the embodiment shown in FIG. 5, showing the filter section positioned over the orifice; 
     FIG. 11 is a bottom perspective view of FIG. 6 after spaced first and second seals are placed at one end of the tube-like structure and the longitudinal sides of the structure are cut between the seals; and 
     FIG. 12 is a bottom perspective view of the tube-like structure from FIG. 11 wherein the compartment has been sealed to form an end seal thereby forming a single desiccant bag of the present invention having a filter section integrated therein. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning to attached FIG. 1, there is shown a dual desiccant bag  10  of the present invention containing desiccant particles  12  (FIG. 7) therein for use in conjunction with refrigeration and/or drying systems (not shown) that are commonly supplied in automobiles, trucks or other motor vehicles (not shown). 
     The desiccant bag  10  is made from porous fabric  14 , preferably non-woven fabric such as needle punched polyester felts, spun bonded felts, such as spun bonded polyester, spun bonded nylon and spun bonded polyolefin, and other non-woven materials such as flash spun, spunlaced, and meltdown polyester or nylons. The bag further includes a filter section  16  comprising a wall portion  18 , or yoke, disposed about a central axis  20  and having first and second openings  68  and  70  to define a sleeve  22  so that the bag will snugly fit over the U-bend tube  24  (FIG. 2) of an accumulator and/or receiver/dryer structure (not shown) of an automotive refrigeration system and the like (not shown). 
     FIG. 1 further shows the bag  10  comprising first and second longitudinal end portions  26  and  28  having opposing top and bottom layers  30  and  32  comprising a width  36  and having opposing sides  38  and  40  connecting the layers  30 ,  32 . The layers  30 ,  32  further have opposing first and second ends  42  and  44 . The second ends  44  of the layers  30 ,  32  of the first end portion  26  and the second ends  44  of the layers  30 ,  32  of the second end portion  28  are connected to form sealed ends  46  while the first ends  42  opposingly and integrally join the end portions  26 ,  28  with the wall portion  18  so that the first ends  42  run parallel with the central axis  20  and the end portions  26 ,  28  extend outwardly therefrom. The sealed ends  46  may be made via ultrasonic sealing means, heat fusion, stitching or the like. 
     The bag  10  further comprises a seam  48  extending longitudinally across the bag  10  for sealing the bag  10  lengthwise and has first and second seals  50  and  52 . The seam  48  may be made via ultrasonic, heat fusion and/or stitching procedures. The first seal  50  seals together the first ends  42  of the layers  30 ,  32  of the first end portion  26  across the width  36  thereof adjacent the wall portion  18  and the second seal  52  seals together the first ends  50  of the layers  30 ,  32  of the second end portion  28  across the width  36  thereof adjacent the wall portion  18  so that the end portions  26 ,  28  define first and second compartments  54  and  56  wherein the first seal  50  and sealed end  46  of the first end portion  26  define opposing ends of the first compartment  54 , and the second seal  52  and sealed end  46  of the second end portion  28  define opposing ends of the second compartment  56 . The first and second compartments  54 ,  56  are provided with a plurality of desiccant particles  12  (FIG. 7) contained therein. 
     Notably, one can integrate different porous fabric  14  into the wall portion  18  of the bag  10  thereby allowing for different filter characteristics as required by the manufacturer of the accumulator or receiver/dryer canister. For example, if the porous fabric  14  is thought to be too dense to allow for proper lubricant pickup, then a more course fabric  14  may be used in the wall portion  18  at the location where the bag  10  will position over the orifice  58  (FIG.  2 ). 
     Turning to FIG. 2, there is shown a U-bend tube  24  of the type normally encountered in automotive refrigeration systems (not shown). This tube  22  comprises upstanding leg members  60  and  62  and bight portion  64  connecting the upstanding legs  60 ,  62 . The sleeve  22  is snugly and slidably fit over upstanding leg  60  and is then positioned as shown in FIG. 3 over the orifice  58  provided in the bight portion  64  of the tube  24 . 
     FIG. 4 shows another embodiment of the bag  10  wherein the first and second compartments  54 ,  56  are again separated by a filter section  16 . In this embodiment an aperture  66  is provided in the filter section  16  between the first and second openings  68 ,  70  of the wall portion  18  so that the aperture  66  can be positioned to receive a separate filter  67  or can be positioned around a separate filter  67  already assembled on the tube. As such, the bag  10  will still be located in place but will not act as a filter. 
     In order to manufacture the dual desiccant bag  10 , a sheet of porous non-woven fabric  100  is provided having opposing longitudinal and lateral side edges  102  and  104  as shown in FIG.  5 . In FIG. 6, the opposing longitudinal side edges  102  are connected, such as by ultrasonic sealing, heat fusion and/or stitching procedures, to form a tube-like structure  106  comprising a width  108  and having opposing top and bottom layers  30 ,  32 , opposing sides  38 ,  40  connecting the layers  30 ,  32 , and opposing first and second ends  110  and  112  having openings  114 . The longitudinal side edges  102  are connected such that the seam  48  extends longitudinally across the tube-like structure  106 . 
     Next, spaced first and second seals  50 ,  52  are placed intermediate the ends  110 ,  112  of the tube-like structure  106  as shown in FIG.  7 . The seals  50 ,  52  seal across the width  108  of the tubular structure  106  connecting the top layer  30  of the tube-like structure  106  with the bottom layer  32  so that the first and second ends  110 ,  112  define first and second compartments  54 ,  56  provided with openings  114 . Then, as further shown in FIG. 7, the opposing sides  38 ,  40  between the first and second seals  50 ,  52  are sliced lengthwise using a cutting tool or die (not shown) to form a filter section  16  having a wall portion  18 , or yoke, disposed about a central axis  20  and having first and second openings  68 ,  70  to define a sleeve  22 . Lastly, the compartments  54 ,  56  are filled with desiccant  12  and sealed shut via ultrasonic, heat fusion and/or stitching procedures, as shown in FIG. 8, so that the ends  110 ,  112  have sealed ends  46  for containing particles  12  within the compartments  54 ,  56 . 
     If necessary, and in order to provide a bag  10  as shown in FIG. 4, an aperture  66  further is provided in the filter section  16 , preferably intermediate the first and second openings  68 ,  70  of the wall portion  18 . 
     Accordingly, as shown in FIGS. 2 and 3, once the bag  10  is completed, the filter section  16  receives a leg  60  of the U-bend tube  24  through its sleeve  22  and the bag  10  is easily slid thereon until the filter section  16  is situated over the orifice  58 . The bag  10  fits around the tube  24  so the filter section  16  can act as a filtering device at the orifice  58  while gravity firmly holds the bag  10  in the bottom of a canister (not shown) thereby acting as a method to hold the bag  10  in place. The wall portion  18  can be adjusted to fit tightly over the U-bend tube  24  once assembled. 
     Turning now to the embodiment shown in FIG. 9, a single desiccant bag  200  is shown. 
     In this embodiment, the desiccant bag  200  comprises only one compartment  54  for containing desiccant particles  12  (FIG. 11) therein. This bag  200 , similar to the dual desiccant bag  10  (FIG.  1 ), has a filter section  16  comprising a wall portion  18  disposed about a central axis  20  having first and second openings  68 ,  70  to define a sleeve  22 . 
     The bag  200  further includes a longitudinal end portion  26  having opposing top and bottom layers  30 ,  32  comprising a width  36  and having opposing sides  38 ,  40  connecting the layers  30 ,  32 . The layers  30 ,  32  further have opposing first and second ends  42 ,  44 . The second ends  44  are connected to form a sealed end  46  while the first end  42  is integrally joined with the wall portion  18  so that the first end  42  runs parallel with the central axis  20  and the end portion  26  extends outwardly therefrom. The sealed end  46  may be sealed via ultrasonic sealing means, heat fusion, stitching or the like. 
     The bag  200  also comprises a seam  48  extending longitudinally across the bag  200  for sealing the bag  200  lengthwise and has first and second seals  50 ,  52 . The seam  48  may be made via ultrasonic, heat fusion and/or stitching procedures. The second seal  52  seals along the length of the wall portion  18  and the first seal  50  seals together the first ends  42  of the layers  30 ,  32  of the end portion  26  across the width  36  thereof adjacent the wall portion  18  so that the end portion  26  defines a compartment  54  wherein the first seal  50  and sealed end  46  of the end portion  26  define opposing ends of the compartment  54 . Preferably, the seals  50 ,  52  are opposingly positioned such that the filter section  16  is situated between the first and second seals  50 ,  52 . Additionally, the second seal  52  may extend outwardly from the wall portion  18 . Lastly, the compartment  54  has a plurality of desiccant particles  12  (FIG. 11) contained therein. 
     The artisan will appreciate that the single desiccant bag  200  shown in FIG. 9, similar to the dual desiccant bag  10  (FIG.  1 ), may further be provided with an aperture  66  (FIG. 4) in the filter section  16 . Also, the artisan will appreciate that one can integrate different porous fabric  14  into the wall portion  18  of the bag  200  thereby allowing for different filter characteristics. 
     FIG. 10 further shows the embodiment of FIG. 9 in its intended position over the bight portion  64  of the U-bend tube  24  of an accumulator or receiver/dryer (not shown). Here, the filter section  16  overlies the orifice  58  in the tube  24 . 
     The single desiccant bag  200  is manufactured similarly to the dual desiccant bag  10  (FIG. 8) such that, as shown in FIG. 5, a sheet of porous non-woven fabric  100  is provided having opposing longitudinal and lateral side edges  102 ,  104 . And, as further shown in FIG. 6, the opposing longitudinal side edges  102  are connected, such as by ultrasonic sealing, heat fusion and/or stitching procedures, to form a tube-like structure  106  comprising a width  108  and having opposing top and bottom layers  30 ,  32 , opposing sides  38 ,  40  connecting the layers  30 ,  32 , and opposing first and second ends  110 ,  112  having openings  114 . The longitudinal side edges  102  are connected such that the  48  seam extends longitudinally across the tube-like structure  106 . 
     Next, as shown in FIG. 11, a first seal  50  is placed across the width  108  of the tube-like structure  106  between the ends  110 ,  112  thereof substantially adjacent the opening  114  of the second end  112 , and a second seal  52  seals across the width  108  of the tube-like structure  106  to seal the opening  114  of the second end  112 . The seals  50 ,  52  connect the top layer  30  of the tube-like structure  106  with the bottom layer  32  and are placed using ultrasonic sealing, heat fusion and/or stitching procedures. Accordingly, the first seal  50  is placed such that the first end  110  defines a compartment  54  provided with an opening  114 . 
     Next, as further shown in FIG. 11, the opposing sides  38 ,  40  of the tube-like structure  106  between the first and second seals  50 ,  52  are sliced lengthwise using a cutting tool or die (not shown) to form the filter section  16  disposed about a central axis  20  and having first and second openings  68 ,  70  to define a sleeve  22 . Lastly, the compartment  54  is filled with desiccant  12  and the opening  114  of the first end  110  sealed shut, as shown in FIG. 12, so that the first end  110  has a sealed end  46  for containing particles  12  within the compartment  54 . The sealed end  46  is formed via ultrasonic, heat fusion and/or stitching procedures. 
     Accordingly, the dual and single desiccant bags of the present invention effectively eliminates the need for a separate filter assembly and separate desiccant bag. As such, the bag of the present invention provides a simple way for combining the bag and filter while at the same time reducing the material and assembly costs associated with separate components. Also, the desiccant bag further keeps large particles from entering the orifice in the U-bend tube. 
     While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention.