Abstract:
A method for providing a hose pipe connection is disclosed. Embodiments of the method start with a pipe having an enlarged end portion. A sleeve is introduced into the end of the flexible hose. The sleeve has an inner diameter that is equal to the inner diameter of the hose. In an embodiment, the inner diameter of the sleeve is increased while the end of the hose is already placed on the sleeve. The hose fitted with the sleeve is then introduced into the enlarged end of the pipe. Crimping of the enlarged end will then secure the sleeve and the hose and provide a fluid tight and mechanically sturdy connection.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of U.S. patent application Ser. No. 12/425,631, filed Apr. 17, 2009, the entire contents of which are herein incorporated by reference. U.S. patent application Ser. No. 12/425,631 claims priority to European application No. 08103615.4, filed 18 Apr. 2008. The European application is hereby incorporated by reference as though fully set forth herein. 
     
    
     BACKGROUND 
       [0002]    Generally the invention relates to a method for connecting a flexible hose member to a socket and in particular for connecting the flexible hose member to a pipe member. Further the invention relates to a connecting arrangement for connecting a flexible hose member to a socket or a pipe member. 
         [0003]    Flexible hoses and rigid pipes are used for conducting fluids such as oil, water, air and/or gas in several applications and in particular in automotive applications. Very often flexible hoses are to be connected to other elements e.g. end fittings, devices or pipes. The flexible hose is typically formed as a composite of different materials including plastic, elastomer, rubber, cords and wires or the like. The connecting technique should provide a reliable and sealed connection. 
         [0004]    U.S. Pat. No. 2,902,299 refers to a hose coupling assembly having a metal sleeve of frusto-conical form which is inserted in an end portion of the hose and is provided with outwardly pressed circumferentially extending rounded beads. The beads coact with shoulders of an internally stepped outer sleeve enclosing the end portion of the hose. The outer sleeve is provided with an external thread or forms a nut, so that two complemental outer sleeves can be provided which can be fastened together. 
         [0005]    Another coupling assembly is shown in U.S. Pat. No. 5,476,291 with a male and a female section which can be threadably interconnected. Two hose ends can be affixed to the male and female section by means of a hub or a collar respectively each having an axial bore for receiving the hose end. 
         [0006]    From WO 01/46611 A1 a coupling assembly for coupling two pipes is known. A coupling piece has a nipple, which is inserted and attached to the plastic pipe by means of radial expansion of the nipple. A nut is connected to the nipple. A coupling piece is screwed in to the metal pipe and provides an external thread to be threadably connected to the nut. 
         [0007]    WO/2006/040082 discloses a tube connection which uses a specifically shaped pipe end which is inserted into the open end of a hose. A retainer serves to fasten the hose end to the tube end. The retainer is anchored to a flange of the tube and comprises two axially extending retaining limbs that are fastened on the outside of the tube by means of tightening straps. The retaining limbs rest between the outside of the tube and the tightening straps and are clamped there between. 
         [0008]    While this assembly provides a reliable and inexpensive connection of the tube and the hose which is easy to produce, the inner diameter of the fluid channel may change at the transition from the tube to the hose. This is due to differing diameters of the pipe and the hose. If on the other hand a tube and a hose of the same inner diameter are used the specifically contoured pipe end has to be driven into the open end of the hose which might require high axial force and cause problems during production. 
         [0009]    While this assembly is generally reliable a pipe connection arrangement is desirable which removes any inner shoulder or change of the inner diameter which could affect the fluid flow. 
         [0010]    Therefore it is an object of the present invention to provide a pipe hose connection having a smooth inner shape. 
       SUMMARY 
       [0011]    The invention uses a sleeve having a tubular portion of a primarily reduced diameter. After having inserted this portion into the open end of a hose, the portion will be expanded until the inner diameter thereof is equal to the inner diameter of the hose. This assembly secured within a socket provides a duct having an even inner wall. The sleeve forms a nipple which has an outer diameter that is larger than the inner diameter of the hose. The flexible hose may in particular include a steel braid or a yarn braid. While those braided hoses are flexible, in general, they are usually that stiff that they withstand all attempts to widen them. This is in particular true in view of tubes which comprise an inner inflexible lining, e.g. made of plastics. This type of linings is often used for tubes for aggressive fluid or fluids which otherwise would solve or permeate the elastomer body of the tube. The inventive method provides a way for placing the nipple within the hose while no axial relative movement of the nipple and the hose is necessary once the nipple and the hose are widened. The method produces an assembly having a smooth stepless inner wall and a uniform inner diameter. 
         [0012]    The nipple can comprise further connecting means as there are flanges, inner or outer threads and so forth. So it can be fluidly connected to other hoses, pipes, fluid channels of apparatuses and assemblies. 
         [0013]    The nipple may be secured within e shell or within a socket. In a preferred embodiment the socket is defined by an expanded pipe end which receives the hose end with the at least partially widened sleeve therein. After compressing zones of the pipe end the hose and the sleeve are fixedly secured therein. Preferably the inner diameter of the pipe is equal to the inner diameter of the sleeve after widening it. In short, the connecting arrangement is formed by a compressible pipe end socket, a flanged expandable sleeve and a hose clamped there between. 
         [0014]    The hose pipe connecting arrangement will in particular avoid any restriction of a fluid flow and provide a very low pressure drop. It can be used for automotive air conditioning systems. Due to the reduced pressure drop the arrangement helps in increasing the efficacy and reducing the power consumption of the system the inventive arrangement is used in. Those systems may be air conditioning systems, hydraulic systems or the like. The inventive system is in particular useful in systems with fluids with high flow velocities. 
         [0015]    The sleeve inserted into the open hose end defines the inner wall of the pipe connector. Moreover it provides an inner abutment for the flexible wall of the hose. The socket portion of the pipe end comprises inwardly deformed zones which press the wall of the hose against the outer circumferential surface of the sleeve. Consequently the hose is clamped between the sleeve and the socket and will be securely held. So, the invention provides both a durable mechanical connection and a tight seal. It is in particular made sure that the inner diameter of the channel will not be reduced by deforming the socket portion. The sleeve will prevent the hose from collapsing or even decreasing the cross section of the duct as a result of the application of inwardly directed compressing forces. 
         [0016]    Preferably the tubular extension comprises a smooth cylindrical inner circumferential surface. Also it may have a smooth cylindrical outer surface. However the outer surface of the sleeve may be provided with fastening means for better securing the hose on the sleeve. To this end the outer surface may be provided with a serration, annular ribs, bulges, teeth, protrusions, indentations or the like. 
         [0017]    A flange may be provided on one end of the sleeve. The flange may engage a compressed zone of a socket portion. This will help the joint to resist axial forces, stresses and vibrations and hence increase the reliability of the connecting arrangement. 
         [0018]    Optionally sealing members may be placed on the sleeve on at least one of the elongate tubular portion and the flange portion. Sealing members may be omitted if the interface between the sleeve and the inner wall of the hose and the socket and the outer surface of the hose will provide a fluid tight seal anyway. 
         [0019]    Further details and advantages embodiments of the invention are to be taken from the drawing, the description or the claims. The description is reduced to main topics of the invention and related facts as well. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    One illustrative embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: 
           [0021]      FIG. 1  is a cross sectional view of the connecting arrangement according to the present invention; 
           [0022]      FIG. 2  is a cross sectional view of a pipe end before deformation; 
           [0023]      FIG. 3  is the pipe end partially expanded for forming a socket portion; 
           [0024]      FIG. 4  is a cross sectional view of a hose end; 
           [0025]      FIG. 5  is a cross sectional view of a sleeve having a tubular extended portion with reduced diameter; 
           [0026]      FIG. 6  is a cross sectional view of the sleeve inserted into the hose; 
           [0027]      FIG. 7  is a cross sectional view of the arrangement according to  FIG. 6  after expansion of the tubular extension; 
           [0028]      FIG. 8  is a cross sectional view of the connecting arrangement before compression of the socket portion of the pipe end; and 
           [0029]      FIG. 9  is a cross sectional view of an alternative embodiment of the inventive connecting assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]      FIG. 1  illustrates a tube connecting arrangement undetachably connecting a pipe  2  and a hose  3 . The pipe may be of any suitable type, e.g. a thin walled steel pipe. It may be consist of any suitable matter, e.g. steel, stainless steel, copper, aluminium or any other plastically deformable material. The hose  3  preferably consists of at least one sheet of an elastomeric material optionally reinforced by a textile material, steel wires or the like. The pipe  2  and the hose  3  both have end portions  4 ,  5  and ducts  6 ,  7  extending therefrom. The ducts  6  and  7  each have a diameter  8 ,  9 . The diameter  8  is preferably equal to the diameter  9 . The end portion  4  forms a socket receiving and mechanically securing end  5  therein. A flared out end  4   a  of the socket circumscribes the hose  3  in a radial distance and provides some protection of the hose  3 . 
         [0031]    The end portions  4  and  5  overlap and define a connecting region. A sleeve  10  is located within the connecting region and within the end portion  4  of pipe  2 . The sleeve  10  comprises a through bore having a cylindrical wall defining a diameter  11 . Diameter  11  is preferably equal to diameters  8  and  9 . The outer circumferential surface of the sleeve may be smooth. Alternatively it may be provided with retainer means, e.g. ribs, bulges, teeth or the like which provide a form fitting engagement of the sleeve and the hose thereon. 
         [0032]    The sleeve  10  comprises an annular flange  12  and a frustoconical end surface  13  provided thereon. The outer circumference of the flange  12  is defined by a cylindrical surface  14 . Optionally at least one sealing element  15  may be provided in a groove intersecting the outer surface  14 . The sealing element  15  may be any suitable preferably annular sealing element, e.g. an O-Ring or the like. 
         [0033]    A tubular extension  16  extends from the flange  12  into the open end  5  of the hose  3 . The tubular end  16  preferably ends on a rounded annular edge  17 . A shoulder  18  may be provided between the flange  12  and the tubular extension  16 . The tubular extension  16  may optionally carry one or several sealing elements, for example O-Rings  19 ,  20 . 
         [0034]      FIGS. 2 ,  4  and  5  illustrate the pipe  2 , the hose  3 , and the sleeve  10  before assembly. As to be seen, the sleeve  10  comprises a reduced diameter portion. A considerable length of tubular extension  16  has a reduced diameter  21  which is much lesser than diameter  11 . A frustoconical transition zone  22  is located closed to the shoulder  18 . The reduced diameter portion of the tubular extension  16  comprises an outer diameter  23 , which is smaller than, equal to, or even slightly greater than the inner diameter  9 . Preferably the diameter  23  is selected to facilitate inserting sleeve  10  into the open end  5  of the hose  3 .  FIG. 6  illustrates the assembly of the sleeve  10  and the hose  3 . 
         [0035]    While  FIGS. 2 to 5  illustrate the pipe  2 , the hose  3  and the sleeve  10  before assembly and deformation, the following will describe the assembling and deformation process for establishing the pipe connection of  FIG. 1 . 
         [0036]    A first step involves flaring out of the end  4  of pipe  2  by expanding the cross section of end  4  of pipe  2 . This expansion can be performed in a warm or cold metal working process by using any suitable technique. The end portion  4  defines a cylindrical inner wall  24  and a conical shoulder  25  between the cylindrical portion  24  and the pipe  2 . The opposite end of the inner wall  24  may somewhat diverge. The end portion  4  is a socket for receiving the hose. 
         [0037]    Another step involves introducing the sleeve  10  as illustrated in  FIG. 5  into the end  5  of the hose  3 . A next step will involve expanding of the extension  16  and thus enlarge the diameter  21 . This can be done by driving a mandrel or any other suitable tool into the through bore of the sleeve  10  to increase the diameter of the tubular extension  16 . As a result the tubular portion  16  will have a uniform inner diameter as illustrated in  FIG. 7 . Preferably the sleeve  10  now has the same inner diameter  11  at both ends thereof. The end  5  of the hose  3  is somewhat widened. 
         [0038]    While in the foregoing the expansion of the tubular extension of the sleeve  10  was illustrated, it is noted that it is also possible to start with a sleeve having a uniform reduced diameter  21 . If this is the case the sleeve  10  will be expanded along its entire length. 
         [0039]    After having provided the assembly of  FIG. 7  in any of the above mentioned techniques it will be inserted into the expanded tubular socket portion  4  of pipe  2  as illustrated in  FIG. 8 . As to be taken from  FIGS. 3 and 8 , the inner diameter  27  of the socket portion  4 , i.e. its bore, is preferably somewhat larger as the outer diameter of the outer circumferential surface  14  and/or the sealing element  15 . Also, the diameter  27  is preferably somewhat larger than the outer diameter of the end portion  5  of hose  3 . Consequently the hose sleeve assembly may be easily introduced into the socket portion  4  until the end surface  13  abuts on the conical shoulder  25 . 
         [0040]    A next step involves the deformation of the end portion  4  in order to transform it from the shape of  FIG. 8  into the shape of  FIG. 1 . Radial inwardly directed forces will be applied in at least one, preferably some locations, preferably annular zones  28 ,  29 ,  30  and create annular grooves  31 ,  32 ,  33 . Groove  31  fits between the shoulder  18  and end the surface  34  of the hose  3 . The groove  31  axially secures the sleeve  10  and firmly connects it to the pipe  2 . The grooves  32  and  33  clamp the end portion  5  against the outer circumferential surface of the tubular extension  16 . Consequently the hose  3  is fixedly secured between the socket portion  4  of the pipe  2  and the tubular extension of the sleeve  10 . The sleeve  10  will provide a firm abutment and prevent any reduction of the diameter  11  during the deformation of the socket portion. 
         [0041]      FIG. 9  discloses another embodiment of the inventive hose pipe connection assembly similar to the one shown in  FIG. 1 . Like reference numbers refer to similar elements. The previous description is also valid for the embodiment of  FIG. 9 . 
         [0042]    The sleeve  10  was fit into the open end while the outer diameter of the sleeve  10  was smaller than the diameter  9 . Thereafter the sleeve  10  was widened so that the inner diameters  9  and  11  were made equal. The hose end  5  was widened without having to urge the hose onto a larger diameter nipple. The inventive method particularly provides a way for widening very stiff braided hoses, which additionally might be provided with a liner  34 , in an easy and simple process. Moreover, it provides a way to fit the hose end  5  over the tubular portion of sleeve  10  without shaving the o-rings  19  and  20  or any other similar sealing element. 
         [0043]    The sleeve  10  may comprise a socket end  35  which can receive the pipe end  4 . A sealing element for example, o-ring  36  may be provided within an inner groove of this socket end  35  or an outer groove of the pipe end  4 . The pipe end  4  may be provided with a radial flange  37  for securing the pipe end  4  on or in the socket end  35 . 
         [0044]    The whole assembly may be held together by retainer means which may be formed by a shell  38 . In the preferred embodiment shell  38  is formed by a sleeve which is at least locally radially deformed and compressed for securing the hose end  5  at the widened portion of the sleeve  10  and for axially clamping flange  37  against the end surface of the socket end  35 .