Abstract:
A hose coupling comprising a main body having a hose nipple section with at least one barb formed thereon, and a retention spring extending from a collar formed on the main body, the retention spring overlying a portion of the hose nipple section where the retention spring applies a clamping force on a hose that is trapped and held in position between the retention spring and the hose nipple section by the barb(s).

Description:
FIELD OF THE INVENTION 
     The present invention pertains to a mechanical hose coupling for connecting a flexible elastomeric fluid conveying hose or tube to a pressurized fluid system. The pliable hose is retained onto the hose fitting by barbs extending from a hose nipple section of the hose coupling and a retention spring that is attached to a collar and extends outwardly to overlie the hose nipple section thereby applying a clamping force on the hose that is maintained under a variety of operating conditions. 
     BACKGROUND OF THE INVENTION 
     Mechanical fluid connections for joining pliable hoses such as a flexible elastomeric or polymeric fluid conveying hose to a pressurized fluid system have traditionally consisted of a barbed hose nipple that is inserted into a pliable hose. The barbs “bite” into the inside layer of the hose and function to retain the hose in position on the hose nipple. In some installations, a clamp such as a band clamp or a wire twist clamp is installed over the hose to apply additional clamping force on the outside of the hose to increase the retention of the hose on the barbs 
     Prior art clamps such as band clamps or single or double wire spring clamps have been used to apply additional clamping force on the outside of the hose. For example, U.S. Pat. No. 3,805,337 to Branstetter discloses a single wire self-tightening spring hose clamp that is commonly used to apply a clamping force on a pliable hose to retain it on a barbed fitting. This is shown as clamp 10 in FIGS. 1-3 of the &#39;337 patent. 
     U.S. Pat. No. 3,333,871 to Abbiati et al, discloses a dual wire self-tightening spring hose clamp that is used to apply a clamping force to a pliable hose to assist in retaining the hose in place on a barbed hose nipple of a hose coupling fitting. This spring hose clamp is shown in FIG. 2 as clamp 35 in the &#39;871 patent. 
     U.S. Pat. No. 4,299,012 to Oetiker, discloses a band type hose clamp where its ends are clipped together upon assembly by extending hooks which engage apertures. The clamp can be tightened further by a bolt fastener which, upon rotation, further reduces the inside diameter of the clamp. 
     These clamps have proven difficult to handle in a production process because the clamps are separate pieces and their performance in some applications is suspect. Installation on the hose requires the use of a tool that can prove difficult to use in constricted environments. Also, after some period of time in service, the clamping force of the clamp degrades due to a permanent deformation under the clamp. Under high pressures, the tube or hose can experience a change in wall thickness due to axial stresses. This thinning of the wall thickness can result in a decreased clamping force on the hose when prior art clamping systems are used to apply a clamping load. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of the exemplary hose coupling without the hose installed; 
         FIG. 2  is a cross-sectional view of the retention spring as shown on the exemplary hose coupling of  FIG. 1 ; 
         FIG. 3  is a perspective view of the retention spring of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view of the exemplary hose coupling assembly with the retention spring fully compressed just prior to installation of the hose; 
         FIG. 5  is a cross-sectional view of the exemplary hose coupling assembly with the hose installed on the and the retention spring still compressed; 
         FIG. 6  is a cross-sectional view of the exemplary hose coupling assembly of  FIG. 5  with the retention spring released and the spring collar pressing against the hose; 
         FIG. 7  is a cross-sectional view of an alternative embodiment of the retention spring as shown in  FIG. 7 ; 
         FIG. 8  is a perspective view of the alternative embodiment of the retention spring of  FIG. 8 ; 
         FIG. 9  is a cross-sectional view of an alternative embodiment of the hose coupling assembly of  FIG. 8 ; and 
         FIG. 10  is a perspective view of the alternative embodiment of the hose coupling with the retention spring installed. 
     
    
    
     SUMMARY 
     What is disclosed is a hose coupling for securing a hose or tube to the coupling body using a hose hose nipple having at least one coupling barb. A retention spring is mounted on the hose coupling body to provide a hose coupling that is one piece prior to assembly of a hose or tube onto the hose coupling. The retention spring at partially covers the hose hose nipple and is retained on the body of the hose coupling at a first end and has a spring collar on a second end. The spring collar has a chamfer which contacts and presses against the hose at the hose hose nipple after the spring is first compressed for assembly of the hose onto the hose hose nipple and over the barb. The retention spring generates both an axial and a vertical force component on the hose which clamps it to the coupling barb. When the retention spring is compressed, the hose is pressed over the hose hose nipple and the coupling barb and against a hose stop formed in the hose hose nipple. Then the retention spring is released and allowed to axially extend and force the spring collar against the hose at the coupling barb. This applies a clamping force on the hose thereby securing the hose to the coupling barb and to the hose hose nipple of the hose coupling. 
     This clamping force is maintained as the hose thickness increases or decreases due to changes in the operating pressures. The exemplary hose coupling exhibits a radial compliance that allows for variance in the wall thickness of the hose or tube. The hose coupling also exhibits an axial compliance that allows for variance in the axial dimensions of the hose and the hose coupling When relatively high internal pressures create high tensile and axial stresses within the hose or tube wall that can result in strain induced stretching of the hose. The exemplary hose coupling has some axial compliance which automatically adjusts for the axial variations. 
     The spring collar is shown as having a chamfer that contacts the hose when the hose is installed on the hose nipple and the retainer spring is released. The angle of the chamfer interacts with the geometry of the hose nipple barb and the geometry of the hose to determine the level of axial and vertical forces applied to the hose by the retention spring. These dimensions and specific geometry and the spring characteristics can be varied and selected depending on the specific application to provide the required clamping force of the hose on the hose coupling. 
     DETAILED DESCRIPTION 
     Referring now to the discussion that follows and also to the drawings, illustrative approaches to the disclosed systems and methods are shown in detail. Although the drawings represent some possible approaches, the drawings are not necessarily to scale and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the present disclosure. Further, the descriptions set forth herein are not intended to be exhaustive or otherwise limit or restrict the claims to the precise forms and configurations shown in the drawings and disclosed in the following detailed description. 
     Moreover, a number of constants may be introduced in the discussion that follows. In some cases illustrative values of the constants are provided. In other cases, no specific values are given. The values of the constants will depend on characteristics of the associated hardware and the interrelationship of such characteristics with one another as well as environmental conditions and the operational conditions associated with the disclosed system. 
     What is disclosed is a hose coupling for securing a hose or tube to the coupling body using a hose nipple having at least one coupling barb. A retention spring is mounted on the hose coupling body to provide a hose coupling that is one piece prior to assembly of a hose or tube onto the hose coupling. The retention spring at partially covers the hose nipple and is retained on the body of the hose coupling at a first end and has a spring collar on a second end. The spring collar has a chamfer which contacts and presses against the hose at the hose hose nipple after the spring is first compressed for assembly of the hose onto the hose nipple and over the barb. The retention spring generates both an axial and a vertical force component on the hose which clamps it to the coupling barb. When the retention spring is compressed, the hose is pressed over the hose nipple and the coupling barb and against a hose stop formed in the hose hose nipple. Then the retention spring is released and allowed to axially extend and force the spring collar against the hose at the coupling barb. This applies a clamping force on the hose thereby securing the hose to the coupling barb and to the hose hose nipple of the hose coupling. 
     This clamping force is maintained as the hose thickness increases or decreases due to changes in the operating pressures. The exemplary hose coupling exhibits a radial compliance that allows for variance in the wall thickness of the hose or tube. The hose coupling also exhibits an axial compliance that allows for variance in the axial dimensions of the hose and the hose coupling when relatively high internal pressures create high tensile and axial stresses within the hose or tube wall that can result in strain induced stretching of the hose. The exemplary hose coupling has some axial compliance which automatically adjusts for the axial variations. 
     The spring collar is shown as having a chamfer that contacts the hose when the hose is installed on the hose nipple and the retainer spring is released. The angle of the chamfer interacts with the geometry of the hose nipple barb and the geometry of the hose to determine the level of axial and vertical forces applied to the hose by the retention spring. These dimensions and specific geometry and the spring characteristics can be varied and selected depending on the specific application to provide the required clamping force of the hose on the hose coupling. 
     Now referring to  FIG. 1  of the drawings, a cross-section of an exemplary hose coupling  12  is shown. The hose coupling assembly  10  is comprised of a hose coupling  12 , a hose  22  and a retention spring  20 . Note that the exemplary hose coupling  12  can be used to connect with a tube or a hose. For example, a single or multiple layer elastomeric or polymeric hose can be used for a polymeric tube or any combination of materials or layers can be used with the hose coupling as disclosed herein. The hose coupling  12  is made up of a coupling body  14  and a retention spring  20 . The hose nipple  16  extends from and is part of the coupling body and the hose nipple  16  includes a hose stop  18  formed therein. The hose stop  18  functions to prevent the hose  22  from being inserted past the location of the hose stop  18  by abutting the hose  22 . Extending from the coupling body  14  is a cylindrical coupling collar  19  which provides a mounting surface and support for retention spring  20  which is attached to the coupling collar  19  at the spring base  36 . Axially extending along the central axis  25  of the hose coupling  12  is passageway  24  which carries the fluid that is to be transported. To seal the hose coupling  12  to some other fluid device such as a pump, valve or other coupling (not shown) are seal grooves  26  that accommodate some type of sealing element such as an O-ring. Typically, devices such as O-rings are positioned within the seal grooves  26 , one within each groove  26  to provide a secure sealing function so that the fluid being transported does not leak outside of the hose coupling  12 . 
     Extending from and as part of the hose nipple  16  is at least one hose barb  28  which can have a variety of shapes including that shown in  FIG. 1 . The hose barb  28  provides a surface on the hose nipple  16  that has an increased thickness for providing an area of increased sealing between the hose nipple  16  and the hose  22  (see  FIG. 5 ). The barb  16  also provides a surface that interacts with the hose  22  to deflect it upward so that the spring collar  32  can apply both axial and vertical force components on the hose  22  to increase the sealing clamp force on the hose  22  against the hose nipple  16 . 
     Now referring to  FIG. 2  of the drawings, a plan view of the retention spring  20  is shown. The retention spring  20  as shown, is comprised of a triple helical spring  34  which is made up of a number of spring coils  34 A,  34 B,  34 C which are connected at their terminations by, at one end, the spring collar  32  and at the other end by a spring base  36 . The spring base  36  is mounted to the collar  19  on the coupling body  14  (see  FIG. 1 ). The spring collar  32  has a spring chamfer  33  at its inner edge where the spring chamfer  33  contacts the hose  22  at the hose barb  28  to apply an axial and a vertical force components with a resulting clamping force on the hose  22  to the hose nipple  16 . 
     Example specifications for the retention spring  20  and the tubing  22  are as follows: the tubing is a 12.5 mm diameter having a 1.0 mm wall thickness and made out of Nylon-12 material. The spring rate of the retention spring  20  depends on the alloy used for the retention spring  20  but is in the range of 120 to 150 lbs/in if the retention spring  20  is made from 15-5 PH CRES at condition 1025 or a 17-7 PH spring condition. The specifications for the hose coupling assembly calls for the retention spring  20  to be compressed by approximately 0.3 inches when it is released after assembly and is applying an axial and a compressive force to the hose  22  at the hose nipple barb  28 . This equates to a compressive force (perpendicular to the axis of the coupling body  12 ) of 37 lbs to 50 lbs. Note that a separate spring compression tool is required at assembly to compress the retention spring  20  a sufficient distance to allow the hose  22  to be inserted onto the hose hose nipple  16  under the retention spring  20  in its compressed state. 
     The retention spring  20  provides a relatively constant clamping force on the hose  22  at higher pressures since as the axial load increases on the hose coupling assembly  10  due to mechanical forces and due to pressure of the fluid. The retention spring  20  increases its installed length to compensate for the reduction in wall thickness of the hose  22  due to stretching of the hose  22  and at very high pressures, the total hose coupling assembly  10 . 
     The retention spring  20  is shown in  FIG. 2  as a three lead hybrid spring consisting of spring coils  34 A,  34 B and  34 C. The spring coils  34 A,  34 B and  34 C begin at the spring collar  32  and extend downwardly to the spring base  36 . The spring coils  34 A,  34 B and  34 C can be any type of known spring types such as a helical spring having some type of appropriate coil cross section such as round, rectangular, hexagonal or octagonal wire or a compression spring, a wave spring, a Belleville spring washer or any other type of material or configuration as long as the force characteristics required for this application are satisfied and the teachings of this disclosure are followed. 
     Now referring to  FIG. 3  of the drawings, a perspective view of the retention spring  20  is shown. The retention spring  20  is comprised of a helical spring  34  which is made up of a number of spring coils  34 A,  34 B,  34 C which are connected at their terminations by, at one end, the spring collar  32  and at the other end by a spring base  36 . 
     The retention spring  20  is shown in  FIGS. 2 &amp; 3  as a three lead hybrid spring consisting of spring coils  34 A,  34 B and  34 C. The spring coils  34 A,  34 B and  34 C begin at the spring collar  32  and extend downwardly to the spring base  36 . The spring coils  34 A,  34 B and  34 C can be any type of known spring types such as a helical spring having some type of appropriate coil cross section such as round, rectangular, hexagonal or octagonal wire or a compression spring, a wave spring, a Belleville spring washer or any other type of material or configuration as long as the force characteristics required for this application are satisfied and the teachings of this disclosure are followed. 
     Now referring to  FIG. 4  of the drawings, the hose coupling  12  is shown with the retention spring  20  fully compressed to allow the tube or hose  22  to be installed. Hose coupling  12  is comprised of a coupling body  14  which has a hose nipple  16  extending therefrom. The retention spring  20  is shown attached to the coupling body  14  at a coupling collar  19  by a spring base  36  formed at one end of the retention spring  20 . The hose coupling  12  includes the coupling body  14  where the coupling nipple  16  has a hose stop  18  formed therein. The hose stop  18  functions to prevent the hose  22  from being inserted past the location of the hose stop  18  by abutting the hose  22 . Extending from the coupling body  14  is the cylindrical coupling collar  19  which serves as a mounting platform for the retention spring  20  at its spring base  36 . Axially extending along a central axis  25  of the hose coupling assembly  10  is passageway  24  which carries the fluid that is to be transported. To seal the hose coupling  12  to some other fluid device such as a pump, valve or other coupling (not shown) are seal grooves  26  which carry some type of sealing device such as O-rings which are positioned within the seal grooves  26 , one within each groove  26  to provide a secure sealing function so that the fluid being transported does not leak outside of the hose coupling  12 . 
     Now referring to  FIG. 5 , a cross-section of the exemplary hose coupling  12  is shown having the hose  22  fully pushed onto the hose nipple  16 . To assemble the hose coupling assembly  10 , the retention spring  20  is compressed by some type of spring compression tool so that the spring collar  32  is pushed back past the hose nipple barb  28  far enough to provide clearance for the hose  22  to be pushed onto the coupling nipple  16  at the nose chamfer  30 , then over the hose nipple barb  28  and then up to the hose stop  18 . The hose  22  deforms and is shown as hose bump  23  to at least partially conform to the hose nipple barb  28 . 
     As shown in  FIG. 6 , the retention spring  20  is then released and the retention spring  20  axially moves to contact the hose  22  at the hose bump  23 . There is a circumferential clamping force applied to the hose at the hose bump  23  that traps the hose  22  between the spring collar  32  of the retention spring  20  and the hose nipple barb  28 . There is both an axial force and a radial compressive force applied to the hose  22  forcing it against the hose nipple barb  28  to seal the hose  22  with the hose coupling  12  at the coupling nipple  16  and more specifically at the hose nipple barb  28 . It is contemplated that additional hose nipple barbs could be used and the shape of the hose nipple barbs could be altered to tailor the performance of the hose coupling assembly  10 . 
     Now referring to  FIG. 7  of the drawings, an alternate embodiment of the hose coupling  52  is shown which is comprised of a hose coupling body  54 , a hose nipple  56  and a retention spring  60 . The hose coupling  52  is made up of a coupling body  54  which has a hose nipple  56  where the hose nipple  56  includes a hose stop  58 . Extending from the coupling body  54  is a cylindrical coupling collar  59  which supports the retention spring  60  which is attached to the coupling collar  59  at a spring base  76 . There is a spring chamfer  61  formed on the end of the spring collar  72  that serves to contact the hose  22  at the hose bump  63 . The angle of the spring chamfer  61 , the characteristics of the hose  62  and the geometry of the hose barb  68  largely determine the amplitude of the axial and vertical force components applied to the hose  62  by the retention spring  60 . These geometries must be determined for each specific application and for each particular component material and other characteristics of the hose coupling assembly  50 . Axially extending along the central axis  65  of the hose coupling  52  is passageway  64  which carries the fluid that is to be transported. To seal the hose coupling  52  to some other fluid device such as a pump, valve or other coupling are seal grooves  66  which hold some type of sealing devices, such as an O-rings which are positioned within the seal grooves  66 . One O-ring is positioned within each groove  66  to provide a secure sealing function so that the fluid being transported does not leak outside of the hose coupling  52 . 
     Now referring to  FIG. 8  of the drawings, a perspective view of the retention spring  60  is shown. The retention spring  60  is comprised of a helical spring  74  which is made up of two helix spring coils  74 A,  74 B which are connected at their terminations by, at one end, the spring collar  72  and at the other end by a spring base  76 . The spring collar  72  has a spring chamfer  73  along its inner edge and this spring chamfer  73  contacts the hose  62  at the hose barb  68 . 
     Now referring to  FIG. 9 , a perspective view of the retention spring  60  is shown as a two lead helix spring  74  consisting of spring coils  74 A,  74 B. The spring coils  74 A and  74 B begin at the spring collar  72  and extend downwardly to the spring base  76 . The spring coils  74 A and  74 B can be any type of known spring types such as a helical spring, a round wire compression spring, a wave spring or any other type of material or configuration as long as the force characteristics required for this application are satisfied and the teachings of this application are followed. 
     Example specifications for the retention spring  60  and the hose  62  are as follows: the tubing or hose  62  is a 12.5 mm diameter having a 1.0 mm wall thickness and made out of Nylon-12 material. The spring rate of the retention spring  60  depends on the alloy used for the retention spring  60  with examples of 15-5 PH CRES at condition 1025 or 17-7 PH. The specifications for the hose coupling assembly  50  call for the retention spring  60  to be first compressed and then released after the hose  62  is installed and applies a compressive force to the hose  62  at the hose nipple barb  28 . This equates to a significant compressive clamping force (perpendicular to the axis of the coupling body  52 ). Note that a separate spring compression tool is required at assembly to compress the retention spring  60  a sufficient distance to allow the hose  62  to be inserted onto the hose nipple  56  and under the retention spring  60  in its compressed state. 
     The retention spring  60  provides a relatively constant clamping force on the tube at higher pressures since as the axial load increases on the hose coupling assembly  50  due to mechanical forces and due to pressure of the fluid by simply increasing its installed length to fill in for the reduction in wall thickness due to stretching of the hose coupling assembly  50 . 
     Now referring to  FIG. 10 , a perspective view of the alternate embodiment of the hose coupling  62  with the retention spring  60  assembled onto the coupling body  54  at the coupling collar  59  by the spring base  76 . To assemble the hose coupling assembly  50 , the retention spring  60  is compressed so that the spring collar  72  is pushed back past the nose bump  68  far enough to provide clearance for the hose  62  to be pushed onto the coupling nose  56 , over the hose bump  68  and up to the hose stop  58 . The hose  62  is pushed over the nose chamfer  70  of the hose coupling  52  and over a nose bump  68  formed on the outer surface of the coupling nose  56 . The hose  62  deforms at shown as a hose bump  63  to conform to the nose bump  68  formation. Then the retention spring  60  is released and it axially moves to cover and apply a clamping force by the spring chamfer  71  in the spring collar  72  to the hose  62  at the hose bump  63 . There is a circumferential force applied to the hose  62  at the hose bump  63  and traps the hose  62  between the retention spring  60  and the nose bump  68 . There is an axial force and a radial compressive force applied to the hose  62  forcing it against the nose bump  68  to seal the hose  62  with the hose coupling  52  at the coupling nose  56  and specifically at the nose bump  68 . 
     The present disclosure has been particularly shown and described with reference to the foregoing illustrations, which are merely illustrative of the best modes for carrying out the disclosure. It should be understood by those skilled in the art that various alternatives to the illustrations of the disclosure described herein may be employed in practicing the disclosure without departing from the spirit and scope of the disclosure as defined in the following claims. It is intended that the following claims define the scope of the disclosure and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. This description of the disclosure should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. Moreover, the foregoing illustrations are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application.