Patent Publication Number: US-2007096461-A1

Title: Crimped hose fitting

Description:
BACKGROUND OF THE INVENTION  
      This invention relates generally to the field of hose fittings, and more particularly to fittings, couplings or connectors joined to the ends of flexible hoses by crimping, where the fittings comprise an internal stem member and an external ferrule or sleeve member.  
      In order to connect flexible hoses to other components, it is well known to attach metal fittings, couplers or connectors to the hose ends. The fittings typically comprise two components an internal stem member having a shank or stein that is inserted into the interior of the hose and an external ferrule or sleeve member that is disposed externally about the hose end and interlocks of connects with the stem member such that relative movement in the axial direction is precluded. The ferrule is composed of a malleable metal, such that it can be inwardly deformed in the radial direction by a crimping process such that protrusions, ridges or the like are created in the ferrule which press into the compressible hose, thereby securing the fitting to the hose end.  
      It is obviously very important in high pressure hoses that the fitting be securely affixed to the hose. At the same time, care must be taken to insure that maximizing the security of the fitting and hose combination does not impart excessive stress into the hose, which can lead to catastrophic failure.  
      In one common type of fitting, the shank of the stem member is provided with a series of annular channels at spaced intervals, the channels either formed in the body of the stem member or created by annular ridges or raised portions extending out from the body of the stem member. The tubular ferrule is provided with a series of annular internal annular projection members, such as ridges, barbs or raised areas, which correspond in position to the channels on the stem member. When the ferrule is crimped and deformed to secure the fitting to the hose, the combination of the annular projections and annular channels compress the hose end into a series of corresponding annular hills and valleys.  
      A problem with this well known type of fitting is that no consideration is given to the fact that when the ferrule is crimped deformation in the axial direction occurs in addition to deformation in the radial direction. Testing reveals, for example, that a ferrule may elongate roughly 7.5 percent from its non-deformed dimensions. This elongation results in alteration of the spacing and positioning of the annular projection members in the axial direction, meaning that the annular projections are no longer precisely aligned with the annular channels on the stem after the crimping operation. This results in unwanted stress points and a less than optimum connection between the fitting and the hose, reducing the working integrity of the hose and fitting combination and increasing the likelihood of failure in the fitting connection or breach of the hose wall.  
      It is an object of this invention to address this problem by providing a fitting for a flexible hose that accounts for the axial elongation of the ferrule relative to the shank of the stem member during the crimping operation, such that the annular internal projections of the ferrule properly align with the annular channels of the shank after the fitting has been secured to the hose end, and in a manner such that there is less compression and deformation than with traditional crimping methods.  
     SUMMARY OF THE INVENTION  
      The invention is in general a fitting, connector or coupling for a flexible hose end and the combination of such a fitting and hose, wherein the fitting comprises a stem member having a hollow shank or stem that is inserted within the bore of the flexible hose and a ferrule or sleeve that externally surrounds the end of the hose, the ferrule being composed of a malleable metal such that it may be crimped onto the hose end and shank to secure the fitting to the hose. The fitting may be provided as a single piece member, or the ferrule may be separate from the stem member and joined during the crimping operation.  
      The external surface of the shank of the stem member is provided with a series of axially spaced annular channels. The interior surface of the ferrule is provided with a series of axially spaced annular internal projection members, wherein the axial spacing of the annular internal projection members differs from the axial spacing of the annular channels. The axial spacing of the annular internal projection members is smaller than that of the annular channels in order to account for the elongation of the ferrule resulting from the crimping operation, such that upon crimping the axial spacing of the projection members will correspond to the axial spacing of the channels and the projection members will be properly aligned with the channels.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a cross-sectional view of a fitting shown prior to crimping the ferrule onto the stem member, illustrating that the spacing of the projection members on the ferrule is different than the spacing of the channels on the stem member.  
       FIG. 2  is a cross-sectional view of the fitting of  FIG. 1  with the ferrule shown as crimped onto the stem member, illustrating that the projection members properly align with the channels due to elongation of the ferrule.  
       FIG. 3  is a cross-sectional view of an alternative embodiment of a fitting similar to that of  FIG. 1 , wherein the fitting is a single-piece member.  
       FIG. 4  is a cross-sectional view of an alternative embodiment of a fitting similar to that of  FIG. 2 , wherein the fitting is a single-piece member.  
       FIG. 5  is a partial cross-sectional view showing the optimum alignment position of a stem member channel.  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      With reference to the drawings, the invention will now be described with regard for the best mode and the preferred embodiment. In general, the invention is crimped fitting for a flexible hose, or the combination of such fitting and hose, wherein the fitting comprises a ferrule having at least one and more preferably a plurality of internal annular projection members and a stem member- having at least one and more preferably a plurality of channels, whereby the projections members properly align with the channel members after the ferrule is elongated by the crimping process. The term fitting shall be taken herein to comprise structures, commonly referred to as fittings, connectors, couplings or the like, that provide a mechanism for connection of the flexible hose to another component. The term flexible hose shall be taken herein to include hoses composed. of rubber, synthetics or the like, whether or not reinforced, that are capable of being compressed such that a fitting having a deformable ferrule can be securely connected to the hose end.  
       FIGS. 1 and 2  illustrate a fitting  10  comprising a ferrule or sleeve member  11  and a stem member  21 , wherein the ferrule  11  and the stem member  21  are individual and separate components prior to the joining operation. The stem member  21  comprises a head or connector portion  22  adapted to be joined to another component of the system, where the head  22  may be threaded, slotted, etc. in order to securely connect to the other component. An elongated hollow shank member  23  extends in the opposite direction from the head  22 , the bore  24  defining a longitudinal axis for the stem member  21 . Means to retain the ferrule  11  is provided, which as shown comprises an interlock shoulder  25  and interlock groove  26 .  
      The ferule  11  is composed of a malleable metal material and comprises a generally tubular, relatively thin-walled, sleeve body  12  and an interconnecting annular flange member  13  adapted to be received and retained by the stem member  21  such that the ferrule  11  cannot be removed from the stem member  21  after the crimping operation. The interior surface of the sleeve body  12  is provided with at least one and more preferably a series or plurality of axially spaced, internal annular projection members  14 , often referred to as barbs, ridges or the like. The spacing and configuration of the projection members  14  may vary, and the projection members  14  may be segmented but are preferably continuous over 360 degrees. For example, the projection members  14  may be evenly spaced in the axial direction, may have increasing or decreasing spacing between each projection member  14 , or may be randomly or variably spaced. The dimensions and configuration of the projection members  14  may vary and will often depend on the particular composition of the hose  90  to which the fitting  10  is to be attached.  
      The exterior of the shank  23  is provided with at least one and more preferably a series of axially spaced annular channels  27 . The channels  27  may be structured as recesses cut into the surface. of the shank  23  or as recesses defined by ridges or raised areas disposed on the surface of the shank  23 . The spacing and configuration of the channels  27  may vary, and the channels  27  may be segmented but are preferably continuous over 360 degrees. For example, the channels  27  may be evenly spaced in the axial direction, may have increasing or decreasing spacing between each channel  27 , or may be randomly or variably spaced. The depth, width and angle of the walls and bottoms of the channels  27  may vary, depending on the dimensions of the projection members  14  and the composition of the hose  90 . Each channel  27  will however have an optimum alignment position  31 , as shown in  FIG. 5 , for receiving the stresses and compressive forces resulting from the corresponding crimped projection member  14 , the optimum alignment position  31  often corresponding to the center of the channel  27 . The axial-spacing of the projection members  14  and the channels  27  must correspond in a predetermined manner. In other words, the axial spacing of the projection members  14  is dependent on the axial spacing of the channels  27 , and vice versa. Each projection member  14  is paired with a corresponding channel  27 . Prior to the crimping operation, the axial spacing of the projection members  14  on the ferrule  11  is smaller than the axial spacing of the channels  27  on the shank  23 , such that the projection members  14  are not properly aligned with the optimum alignment positions  31  of the channels  27 . Upon performance of the crimping operation, the sleeve body  12  elongates, such that the axial spacing between the projection members  14  is expanded and the projection members  14  are now properly spaced and aligned with the channels  27 .  
      To attach the fitting  10 , the shank  23  of the stem member  21  is inserted into the hose bore  92  of the flexible hose  90 , such that the hose end  91  abuts against the interlock shoulder  25 , the external diameter of the shank  23  having been chosen to properly correspond to the diameter of the hose bore  92 . The ferrule  11  is disposed around the hose end  91  such that the interconnecting flange member  13  of the ferrule  11  is properly aligned with the interlock groove  26  of the stem member  21 , as shown in  FIG. 1 . Upon crimping or through an alternative joining operation, deformation of the ferrule  11  results in the joining of the interconnecting flange  13  of the ferrule  11  to the interlock groove  26  of the stem member  21 , securing the ferrule  11  to the stem member  21  to preclude relative axial movement and thereby creating the complete fitting  10 , as shown in  FIG. 2 . The deformation of the sleeve body  12  in the radial direction compresses the hose  90  between the sleeve body  12  and the shank  23 , while simultaneously elongating the sleeve body  12  such that the axial spacing of the projection members  14  is increased to the point where the axial spacing of the projection members  14  corresponds and aligns with the axial spacing of the channels  27 , and the projection members  14  align with the optimum alignment position  31  of the channels  27  such that the paired projection members  14  and channels  27  now correspond and optimal securing of the fitting  10  to the hose  90  is achieved.  
       FIGS. 3 and 4  illustrate an alternative embodiment wherein the fitting  10  is composed of a ferrule  11  joined directly to the stem member  21 , such as by welding, or formed as a unitary component. As before, in the neutral configuration prior to performance of the crimping operation, the axial spacing of the projection members  14  is less than that of the channels  27 , but upon deformation and elongation the axial spacing of the projection. members  14  is properly adjusted such that they properly align with the channels  27 .  
      As a representative and illustrative example, a fitting  11  may comprise a stem member  21  having four channels  27  with angled sides disposed on the shank  23 , the channels  27  being approximately 0.10 inches in width at the shank surface, approximately 0.08 inches in width at the bottom, and approximately  0 . 01  inches in depth. The optimum alignment position  31  of a first channel  27  is 0.147 inches from the interlock shoulder  25 , that of the second channel  27  from the first channel  27  is 0.154 inches, that of the third channel  27  from the second channel  27  is 0.154 inches,. and that of the fourth channel  27  from the third channel  27  is 0.154 inches. The corresponding ferrule  11  has projection members  14  each having a generally perpendicular or slightly angled wall approximately 0.01 inches in height, a width of approximately  0 . 02  inches, and an angled wall extending toward the interior of the hose  90 . In the neutral, pre-crimped status, the axial distance from the interlock shoulder  25  to the first projection member  14 , measured to its midpoint, is approximately 0.135 inches, that of the second projection member  14  from the first projection member  27  is approximately  0 . 143 , that of the third projection member  14  from the second projection member  14  is approximately  0 . 143  inches, and that of the fourth projection member  14  from the third projection member  14  is approximately 0.143 inches. In other words, the axial separation distance between the channels  27  is approximately 0.154 inches and the axial separation distance between the projection members  14  is approximately 0.143 inches, a reduction of approximately seven percent. When the ferrule sleeve body  12  is deformed radially inward in the crimping operation, the sleeve body elongates approximately  7  percent, thereby increasing the axial spacing between the projection members  14  to approximately 0.154 inches, which corresponds to the axial spacing of the channels  27 . In this manner the projection members  14  are properly aligned with the channels  27  in the post-crimped status. As previously stated, actual dimensions may vary greatly dependent upon many factors of choice, including hose size, hose composition, configuration of the channels  27 , configuration of the projection members  14 , etc. Likewise, the axial separation distances between the channels  27  does not have to be uniform between each adjoining set of channels  27 .  
      Attaching a fitting  10  to a hose  90  in the described manner results in less compression and deformation of the hose  90 , since the hose  90  flows in a waffle-like or undulating manner.  
      It is understood and contemplated that equivalents and substitutions to certain elements set forth above may be obvious to those skilled in the art, and therefore the true scope and definition of the invention is to be as set forth in the following claims.