Abstract:
A removable and reusable multiple application fitting is disclosed that enables removal of the hose without significant damage to the hose. The removable and reusable multiple application fitting properly seals with hoses made of only one compound, such as rubber, as well as hoses of multiple compounds with or without linings, such as a rubber hose with a plastic lining. The multiple application fitting has a taper step and o-ring step to guide a hose over an installed o-ring to prevent the o-ring from being displaced during installation. The multiple application fitting is versatile and in some embodiments is used with hoses that require o-rings, and in other embodiments used with hoses that do not.

Description:
FIELD 
       [0001]    This invention relates to a fitting device for connecting a fitting interface end to a hose and more particularly to a fitting device that is used to connect multiple types of hoses, with the hose and the fitting device being removable and reusable. 
         [0002]    This application is related to pending application Ser. Nos. 12/336,723 to Bobenhausen and 12/634,882 to Bobenhausen. 
       BACKGROUND 
       [0003]    Barbed hose fittings have long existed in the prior art. Such fittings come in all shapes and sizes, with many materials and applications. But barbed fittings have many disadvantages. When the hose is compressed on top of the barbs, the sharp and pointed barbs often damage the integrity of the hose, compromising the integrity of the coupling seal, potentially causing leakage. Barbed fittings are difficult to remove once installed in a hose and often cannot be taken out of the hose without causing damage. Additionally, the sharp edge of a barb often causes a scraping on the inside of the hose during application. For hose and fitting combinations with high pressure carrying capability, installation may require tools. 
         [0004]    One attempted solution is present in U.S. Pat. No. 6,010,162 to Grau et al. This patent discloses a hose nipple with at least one circular groove with o-ring. This device uses deeper grooves to hold the o-ring, with “protection and support diameters being larger than said O-ring seal diameter.” (Grau, Col. 6, II 48-49). The centerline of the o-ring is below the surface of the hose nipple, resulting in over half of the o-ring being enclosed by the nipple. This results in a less-effective seal because only a small portion of the o-ring is exposed and in contact with the sealing surface of the hose. This device further includes “barbed serrations” which tend to damage the inner layer of the hose. Finally, this device requires the use of clamps carefully placed over the o-rings in order to properly seal. Misplaced clamps, or the use of ferrules, will result in improper compression, and a poor seal. 
         [0005]    Another attempted solution is present in U.S. Pat. No. 6,460,897 to Manuli. This patent discloses a connector for flexible pipes (i.e. hoses), particularly for cooling systems. The connector uses a sealing ring that is wider than it is thick (known in the industry as a “D-ring”) to avoid rolling/displacing the sealing ring when a hose is slid over the connector. This, therefore, requires the use of non-standard o-rings to prevent the o-ring from being displaced by the leading edge of the hose during installation. Additionally, the use of a D-ring spreads out the force of the ring against the inside of the hose, decreasing the pressure against the hose, making it more difficult to achieve a high pressure seal. 
         [0006]    What is needed is a hose fitting system that seals a hose to a fitting interface end without the use of barbs, providing a strong seal for both lined and unlined hose. 
       SUMMARY 
       [0007]    A removable and reusable fitting is disclosed that enables removal of the hose without significant damage to the hose. The removable and reusable fitting properly seals with hoses made of only one compound, such as rubber, as well as hoses of multiple compounds with or without linings, such as a rubber hose with a plastic lining. 
         [0008]    In one embodiment, a system is disclosed including a multiple application fitting for joining a hose to a fitting interface end, the multiple application fitting comprising a hollow cylinder, the hollow cylinder having an inside surface, an outside surface, a distal end, and a proximal end, the distal end having a fitting interface end, the proximal end having a taper, the taper having a taper step and an insertion surface, one or more o-ring grooves, each o-ring groove circumferentially encircling the hollow cylinder, each o-ring groove having a groove depth, a groove diameter, and an installed o-ring diameter; and one or more o-ring groove depressions, each o-ring groove depression having a depression diameter, and the o-ring groove depressions being a portion of the outer surface at both sides of the o-ring groove. 
         [0009]    In another embodiment, a method of joining a hose to a fitting interface end, the method comprising providing a multiple application fitting, the multiple application fitting having, a hollow cylinder, the hollow cylinder having an inside surface, an outside surface, a distal end, and a proximal end, the distal end having a fitting interface end, the proximal end having a taper, the taper having a taper step and an insertion surface, one or more o-ring grooves, each o-ring groove circumferentially encircling the hollow cylinder, each o-ring groove having a groove depth, a groove diameter, and an installed o-ring diameter, and one or more o-ring groove depressions, each o-ring groove depression having a depression diameter, and the o-ring groove depressions being a portion of the outer surface at both sides of the o-ring groove, providing an end of the hose cut at approximately 90 degrees, placing at least one clamp loosely over the hose, pushing the end of the hose over the hollow cylinder, the end of the hose being pushed past the o-ring groove, positioning the clamp on the hose, over the o-ring groove, and tightening the clamp, thereby compressing the hose against the outside surface of the hollow cylinder. 
         [0010]    In another embodiment, a multiple application fitting for joining a hose to a fitting interface end, the multiple application fitting comprising a hollow cylinder, the hollow cylinder having an inside surface, an outside surface, a distal end, and a proximal end, the distal end having a fitting interface end, the proximal end having a taper, the taper having a taper step and an insertion surface, the taper step having a taper step diameter one or more o-ring grooves, each o-ring groove circumferentially encircling the hollow cylinder, the o-ring grooves having a groove depth, groove diameter, and an installed o-ring diameter one or more o-ring groove depressions, each o-ring groove depression having an depression diameter, and the o-ring groove depressions being a portion of the outer surface at both sides of the o-ring groove and one or more o-ring steps on the outside surface of the hollow cylinder, the o-ring steps having a diameter greater than the depression diameter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
           [0012]      FIG. 1  illustrates a cross-sectional view of the prior art. 
           [0013]      FIG. 2  illustrates a cross-sectional view of the prior art, including a hose. 
           [0014]      FIG. 3  illustrates a cross-sectional view of one embodiment of the device with o-rings. 
           [0015]      FIG. 4  illustrates a cross-sectional view of one embodiment of the device with o-rings, including a multi layered hose. 
           [0016]      FIG. 5  illustrates a cross-sectional view of one embodiment of the device without o-rings. 
           [0017]      FIG. 6  illustrates a cross-sectional view of one embodiment of the device without o-rings, including a hose. 
           [0018]      FIG. 7  illustrates a cross-sectional view of one embodiment of the device with o-rings, shown during installation of a hose. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
         [0020]    Referring to  FIGS. 1 and 2 , a cross-section of the prior art hose fitting  10  is shown. Prior art fittings included barbs  12  that dig into the hose  14 . A hose  14  is installed on the prior art fitting, as shown in  FIG. 2 , a clamp  16  is installed over the hose, compressing the hose. For some hoses, a locking band or hose clamp is used for clamp  16 , and for other hose a ferrule (i.e. a circular ring of metal that is compressed around the hose) is used for clamp  16 , as known in the industry. 
         [0021]    To attach a ferrule, it is compressed radially (i.e., radial crimping) or parallel (i.e., parallel crimping) to the hose. In some embodiments the multiple application fitting is held to the hose using radial crimping, and in other embodiments it is held using parallel crimping. 
         [0022]    Radial crimping results in compression of the ferrule circumferentially, with the compressed portion encircling the hose at one or more locations. In prior art fittings, ideally the locations of radial crimping/compression are coincident with locations between barbs  12 . As discussed, compression of the hose on top of the barb often causes damage. In the multiple application fitting, ideally the locations of radial crimping are coincident with the o-ring  24  locations. 
         [0023]    Parallel crimping results in compression along the length of the hose. In the prior art fitting  10 , parallel crimping often causes problems because the hose  14  is compressed against the barbs as well as the space between. In the prior art this compression of the hose directly over the barbs often causes damage to the hose. 
         [0024]    Pressure from the clamp  16  presses the hose  14  against the fitting  10  and/or barbs  12 , providing a seal. Unfortunately, that same pressure often causes barbs  12  to pierce the inside wall of the hose  14 , weakening the hose  14  by undermining coupling integrity and making it difficult to remove the hose  14  from the fitting  10  without cutting the hose  14 . 
         [0025]    The fitting interface end  10  is any end as known in the art including; threaded ends, quick connect ends, ends with a captive nut to facilitate tightening/loosening, compression end, soldering end, etc. 
         [0026]    While the barbs  12  effectively hold the hose  14  on the prior art fitting  10 , the barbs  12  damage the hose  14  by scraping and scratching the inside wall, protruding through the inner layer of a multiple layer hose, and making it difficult to remove the hose  14  without causing irreversible damage, rendering the hose end useless. For hose and fitting combinations with high pressure carrying capability, the barbed fittings may require tools for installation. 
         [0027]    Referring to  FIGS. 3 and 4 , a cross-section of the applicant&#39;s multiple application fitting  20  with o-rings is shown. The multiple application fitting  20  includes o-ring grooves  22 , with this embodiment having two o-ring grooves  22 . Any other number of o-ring grooves  22  is anticipated. Some embodiments include multiple o-ring grooves  22  immediately adjacent to each other for applications that require greater surface area for sealing. The present embodiment of the device also includes a taper  35  that surrounds the insertion end  32 . The taper has two diameters; a smaller diameter at the insertion surface  34 , and a larger diameter at the taper step  36 . This embodiment also includes o-ring steps  26  that preferably lie between each set of o-ring grooves  22 . In this embodiment, two o-ring steps  26  are shown between the o-ring grooves  22 , but in other embodiments there is only a single step  26 , and in still other embodiments there are three or more steps  26 . In some embodiments the presence of the two or more o-ring steps  26 , rather than only one o-ring step  26 , is beneficial because compression of the hose  50  results in some of the hose  50  material flowing into the gap between the o-ring steps  26 , resulting in an additional seal. This additional seal provides additional tensile strength of the fitting  8  to hose  50  connection, making it more difficult for the fitting  8  to be pulled from the hose  50 . 
         [0028]    In contrast to the prior art, where barbs are present before each set of o-ring grooves  22 , applicant&#39;s device uses o-ring steps  26  with smooth tops. In the present embodiment the top of each o-ring step  26  is shown as flat, but in other embodiments is rounded, ridged, etc. The important differentiation is that there are no sharp barbs pressing against the inside surface of the hose  40  (see  FIG. 4 ). 
         [0029]    The diameter at the taper step  36 , and o-ring steps  26 , is greater than the diameter on either side of the o-rings grooves  22 , with the portion of the fitting  20  that lies on either side of the o-ring groove  22  being the o-ring groove depression  29 . This greater diameter created by the taper step  36  and o-ring steps  26  slightly stretches the hose  40  during installation, guiding it over the top of the o-rings  24 , preventing the hose  40  from pushing the o-rings  24  out of the o-ring grooves  22  as the hose  40  is pushed over the multiple application fitting  20 . The stretching of the hose  40  by the taper step and/or o-ring steps creates a gap  30  between the hose  40  and the surface of the fitting near the o-ring grooves  22 . The diameter of the multiple application fitting  20  at the location of the o-ring groove depression  29  is less than the diameter at the taper step  36 , and/or the diameter at the o-ring steps  26 . This lesser diameter allows the hose  40  to slide over the top of the o-ring  24 , as described above. Because the multiple application fitting  20  does not require that the fitting itself greatly stretch the hose  40  in order to provide a seal, or that sharp barbs penetrate/distort the inner hose wall  4244 , the small amount of stretching caused by the taper and/or step does not hamper insertion of the multiple application fitting  20  into the hose  40 . It is envisioned that no insertion tools are required when using the multiple application fitting  20  with most common hose sizes. Applications for the multiple application fitting  20  with o-rings include cross-linked polyethylene tubing (i.e., PEX or XLPE tubing), as well as other hose and tubing types. 
         [0030]    The o-ring groove  22  has two relevant diameters; a groove diameter and an installed o-ring diameter. The groove diameter is the diameter from the bottom of the depression of the o-ring groove  22 , across the multiple application fitting  20  through the fitting centerline. The installed o-ring diameter is the diameter from the top of an installed o-ring  24 , across the multiple application fitting  20  through the centerline. The installed o-ring diameter is greater than the groove diameter by an amount twice the cross-sectional diameter of the o-ring  24 . (Note that the cross-sectional diameter of the o-ring  24  will decrease slightly in its installed state as compared to its relaxed state due to some stretching and thinning). The groove depth is the approximately one-half the diameter of a cross-section of the o-ring groove  22 . Therefore, in some embodiments approximately one-half of the o-ring  24  lies within the o-ring groove  22 , and approximately one-half protrudes above the surface of the o-ring groove depression  29 . 
         [0031]    The fitting interface end  8  is any end as known in the art including; threaded ends, quick connect ends, ends with a captive nut to facilitate tightening/loosening, compression ends, soldering ends, etc. 
         [0032]      FIG. 4  shows the applicant&#39;s device with a multiple layer hose  40  installed. This embodiment shows the multiple layer hose  40  having two layers  42 / 44 : an outer layer of material  42  that is commonly composed of rubber, and an inner lining layer  44  that is commonly composed of plastic. A multi-layered hose  40  with a plastic lining is often referred to as a “veneer hose.” It is not required that the hose  40  be composed of multiple layers, though that is a common embodiment. The multiple application fitting is equally effective with single layer hoses. All other hose materials and layer quantities are anticipated as known in the industry. 
         [0033]    After the hose  40  is installed, band clamps  46  are installed to compress the hose  40  against the o-rings  24  to provide a tight seal. For hose and fitting combinations with high pressure carrying capability, barbed fittings may require tools for installation. Ferrules are preferred for thicker hose  40  to provide more compression than a hose clamp  46 . When compressing rubber hose  40  using a clamp  46 , typically the wall thickness of the portion of the hose  40  compressed under the clamp  46  is one-third less than the wall thickness of the uncompressed hose  40 . Compression greater than this amount often leads to hose damage, while compression less than this amount is sometimes insufficient to provide proper sealing. All other means of securing the hose  40  to the fitting are anticipated, including bands, clamps, tying, cable tie, shrink-fit, ferrules, etc. 
         [0034]    The multiple application fitting  20  uses o-rings  24  for some hoses  40  of multiple layers because the innermost layer  44  of these multiple layer hoses  40  is composed of a material that does not readily seal against metal fittings. A single layer rubber hose  40 , or a hose  40  with an innermost layer of rubber, provides a tight seal against a metal fitting without the use of o-rings  24  because the rubber hose  40  material expresses, or squeezes, into the o-ring groove  22 . This is different in a hose with a stiffer plastic lining  44  that generally requires at least one o-ring  24  to maintain a proper seal. The o-ring  24  interfaces with the stiffer plastic lining  44  providing a tight seal between the rubber o-ring  24  and the plastic lining of the hose  40 , and the o-ring  24  interfaces with the multiple application fitting  20  providing a tight seal. Although not required, the o-ring  24  is optionally used with a hose  40 / 50  (see  FIG. 6 ) that has an innermost layer  44  of rubber, or is entirely rubber. In some embodiments, hoses  40  with inner layers of material other than plastic require the use of o-rings  24  to achieve a proper seal. 
         [0035]    Referring to  FIGS. 5 and 6 , the multiple application fitting  20  is shown without o-rings. The multiple application fitting  20  includes a taper  35  that surrounds the insertion end  32 . The taper has two diameters; a smaller diameter at the insertion surface  34 , and a larger diameter at the taper step  36 . This embodiment also includes o-ring steps  26  that preferably lie between each set of o-ring grooves  22 . In this embodiment two o-ring steps  26  are shown between the o-ring grooves  22 , but in other embodiments there is only a single step  26 , and in still other embodiments there are three or more steps  26 . In some embodiments the presence of the two or more o-ring steps  26 , rather than only one o-ring step  26 , is beneficial because compression of the hose  40  results in some of the hose  40  material flowing into the gap between the o-ring steps  26 , resulting in an additional seal. This additional seal creates additional tensile strength in the fitting  8  to hose  40  connection, making it more difficult for the fitting  8  to be pulled from the hose  40 . The o-ring groove depression  29  is the portion of the multiple application fitting  20  that lies on either side of the o-ring groove  22 . The diameter of the multiple application fitting  20  at the location of the o-ring groove depression  29  is less than the diameter at the taper step  36 , and/or the diameter at the o-ring steps  26 . This lesser diameter allows for the hose  50  to slide over the top of the o-ring  24 , when an o-ring  24  (not shown) is installed, as described above. For hose  50  having a rubber (or similar) inner surface, o-rings  24  are not required. A gap  30  is present when the hose  50  is in its relaxed state. In this example, the hose  50  is shown composed of a single layer of material, such as rubber  52 . All other hose materials are anticipated as commonly known in the industry. 
         [0036]    The decision of whether to use the multiple application fitting  8  with o-rings  24  or without o-rings  24  depends on how the user wishes the seal to be created. When an o-ring  24  is present, and a hose  40 / 50  is compressed on top of the multiple application fitting  24 , the o-ring is impressed into the hose to create a seal, generally applicable when using a hose with a rubber lining. When an o-ring  24  is absent, and a hose  40 / 50  is compressed on top of the multiple application fitting  24 , the hose  40 / 50  material itself expresses into the o-ring groove  22  where the o-ring would be present, if installed, generally applicable with a hose with veneer, or similar, lining. The greater flexibility of a rubber hose, especially at the inner wall, eliminates the need for an o-ring  24  (not shown). It is anticipated that some multi-layer hoses will retain sufficient flexibility to be used with the multiple application fitting  20  without the use of an o-ring, much like the single layered rubber hose. The decision of whether to use the multiple application fitting  8  with o-rings  24  or without o-rings  24  depends on how the user wishes the seal to be created. When an o-ring  24  is present, and a hose  40 / 50  is compressed on top of the multiple application fitting  24 , the o-ring is impressed into the hose to create a seal. When an o-ring  24  is absent, and a hose  40 / 50  is compressed on top of the multiple application fitting  24 , the hose  40 / 50  material itself expresses into the o-ring groove  22  where the o-ring would be present, if installed. After a hose  50  is installed, band clamps or ferrules  46  are installed to compress the hose to provide a tight seal. As before, any form of clamp or ferrules is anticipated to close and hold a seal between the hose  50  and the multiple application fitting  20 . 
         [0037]    Referring to  FIGS. 3-6 , the general benefits of the multiple application fitting  20  will be described. The multiple application fitting  20  circumvents many of the problems present in the prior art fittings, including barbed fittings, dedicated fittings, and fittings that working only with a specific type of hose or hose material. The integrity of the hose  40 / 50  is maintained because the multiple application fitting  20  has no sharp barbs to penetrate the inner wall of the hose  40 / 50 . The hose  40 / 50  is generally removable and reusable because there are no barbs to damage the structural integrity of the hose  40 / 50 . The multiple application fitting  20  is used with or without o-rings  24 , depending on the application. Aside from the installation or removal of the o-rings  24 , the multiple application fitting  20  remains identical in applications using many different types of hoses  40 / 50 . For example, a user installs the multiple application fitting  20  on a multiple layered hose  40  that requires the use of o-rings  24 , then subsequently remove the multiple layer hose  40 , removes the o-rings  24 , and installs the same fitting  20  on a single layer rubber hose  50 . This versatility reduces the quantity of fittings a supplier needs to keep on hand. Because the sealing properties of the hose  40 / 50  are not dependent on the hose  40 / 50  having a large compressive force against the fitting, generally the fitting is inserted without the use of tools. In the prior art, for hose and fitting combinations with high pressure carrying capability, barbed fittings may require tools to install. This makes the multiple application fitting  20  more practical for use in the field because less hardware is needed, and more economical because it does not require expensive installation tools beyond those already possessed by a typical installer. 
         [0038]    Additionally, if the multiple application fitting  8  is attached with a ferrule, the ferrule is compressed using either radial crimping or parallel crimping. The ability to use either type of compression exists because there are no barbs on the multiple application fitting, and thus compression along the length of the hose will not cause damage. This is unlike the prior art, where such compression across barbs sometimes damages the sealing integrity of the hose. 
         [0039]    Referencing related application Ser. No. 12/336,723, in some embodiments a clamp guide is used to ensure proper placement of the clamps  46  over the o-rings for optimal sealing. Referencing related application Ser. No. 12/634,882, in some embodiments a clamp tool is used to ensure proper placement of the clamps  46 . 
         [0040]    It is important to note that the shape of any given edge on the fitting  20  is not critical. For example, the o-ring groove  22  is not required to be a half-circle as illustrated, and in other embodiments the o-ring groove  22  is square, or triangular. The edges of the o-ring steps  26  are not required to be 90 degrees, and in other embodiments the o-ring steps  26  are rounded, or chamfered. The o-ring steps  26  are also not required to be separate protrusions, and in other embodiments the o-ring steps  26  are a single protrusion. Referring to  FIG. 7 , the benefits of the multiple application fitting  20  during installation are shown. When the hose  70  is first placed over the insertion end  32 , the diameter of the hose  70  is slightly stretched by the taper step  36 , as shown in position  60 . This creates a gap  30  between the hose  70  and the o-ring groove depression  29 . The hose  70  substantially maintains this larger diameter as it moves from position  60  to position  62 . This minimizes the possibility of the hose  70  pushing the o-ring  24  out of the first o-ring groove  22 . Note that it is not necessary that the increase in diameter be large enough to prevent the hose  70  from contacting the o-ring  24 . Rather, the increase in diameter need only be sufficient to prevent the hose  70  from contacting the o-ring  24  at an angle that leads to dislodgement of the o-ring  24 . The taper step  36  diameter and o-ring step  26  diameter are selected to stretch the hose  70  enough such that the hose  70  contacts the o-ring  24  above the centerline of the o-ring  24 . This minimizes any lateral forces, leaving the o-ring  24  within the o-ring groove  22 . Given that the o-ring  24  is only partially exposed, with approximately half of the o-ring  24  disposed within the o-ring groove  22 , the lateral force from the hose  70  is insufficient to unseat the o-ring  24  from its groove  22 . This contrasts with the prior art, in which the o-ring  24  sits substantially beneath the surface of the fitting to avoid being pushed out, or the o-ring  24  has a flat portion lying against the surface of the fitting to prevent it from rolling. As the hose  70  continues to be applied to the multiple application fitting  20 , the taper steps  26  slightly stretch the hose  70  to guide it over subsequent o-rings  24 . 
         [0041]    Referring to  FIGS. 3 and 4 , the dimensions of an example embodiment will be described. This sample embodiment is intended for veneer lined hose  40  with an inner diameter (ID) of 0.625″. For this embodiment, the outer diameter (OD) of the multiple application fitting  20  at the o-ring groove depression  29  is 0.625″, the same as the ID of the hose  40 . At the taper step  36  and the o-ring steps  26  the OD is 0.645″, slightly greater than the ID of the hose  40 . The OD at the innermost point of the o-ring grooves  22  is 0.583″. The o-ring groove  22  itself has a radius of 0.020″, the same as the radius of the o-ring  24 , when the o-ring  24  is in its relaxed, pre-installation state. The o-ring groove depressions  29  have an OD of 0.605″ in this embodiment. The ID of the multiple application fitting  20  in this embodiment is approximately 0.531″. 
         [0042]    Referring to  FIGS. 3 through 6 , the dimensional relationships of an example embodiment will be described. For the purposes of this embodiment, comparisons will be made to a hose  40 / 50  with “D” representing the inner diameter of the hose  40 / 50 . The diameter at the taper step  36  is greater than D to slightly stretch the hose while the multiple application fitting  20  is being inserted and prevent pushing o-ring  24  out of o-ring groove  22 . If an o-ring step  26  is present, the diameter at the o-ring step  26  is also greater than D to slightly stretch the hose before contacting the o-rings  24  beyond the first o-ring  24 . The diameter at the o-ring depression  29  is less than the diameter at either the taper step  36  or the o-ring step  26 , creating a gap  30 . 
         [0043]    Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
         [0044]    It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.