Abstract:
A fast-fit coupling for a fluid circulation system comprising at least two conveying members of a fluid is described; the coupling comprises: a receiving body for each conveying member; fastening means carried by the body, shiftable by the conveying member during the insertion of the conveying member, and integral with the conveying member when the conveying member is moved in a disconnection direction from the body; locking means cooperating with the fastening means to lock the conveying member in a position inside the body and to prevent the body itself from being disconnected; and releasable constraint means, activatable for restraining the locking means to the body and preventing the conveying member to be disconnected, and deactivatable to disconnect the locking means and allowing the conveying member to be disconnected; the locking means and the body are engageable/disengageable by means of a relative rotation less than ninety degrees.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present application claims priority to European Patent Application No. 05425776.1, filed Nov. 4, 2005, which is incorporated by reference herein in its entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to a fast-fit coupling for a fluid circulation system.  
       BACKGROUND OF THE INVENTION  
       [0003]     There are known fast-fit couplings adapted to provide the fluid connection between two or more fluid conveying pipes, while allowing the fast insertion/disconnection of each pipe in the coupling itself.  
         [0004]     In greater detail, the coupling comprises a receiving body defining a plurality of conduits adapted to be engaged by respective fluid conveying pipes and a plurality of openings adapted to allow the insertion/disconnection of each pipe inside a respective conduit.  
         [0005]     The coupling also comprises, for each conduit, a fastening ring provided with a plurality of fins adapted to be shifted from the relative position according to an insertion direction of the pipe itself so as to prevent the further advancement of the pipe itself, a sealing ring adapted to fluid-tightly abut against a side surface of the respective pipe so as to prevent the leakage of fluid, and a sliding locking member inside the body and adapted to cooperate with the pipe on the part opposite to the fastening ring to lock the respective pipe in a predetermined position. More precisely, the locking member is available in a first operative position, in which it locks the pipe on the opposite side of the fastening ring preventing the pipe to be disconnected in the opposite direction to the connection direction, and in a second operative position, in which it does not withhold the pipe on the side opposite to the fins allowing the pipe to be disconnected from the conduit.  
         [0006]     In particular, each locking member is placed adjacent to the respective opening and each fastening ring is interposed between the sealing ring and the locking member.  
         [0007]     During insertion of each pipe, the locking member is available in the first operative position, and each pipe is inserted in the respective coupling body so as to determine the sliding of the pipe itself firstly on the respective fastening ring and then on the sealing ring to reach the predetermined locking position.  
         [0008]     The disconnection of each pipe from the respective conduit occurs by bringing the locking member to the second operative position and pulling out, through the respective aperture, the pipe along with the sealing ring and the locking ring.  
         [0009]     The couplings of the known type provide a suboptimal fluid tightness, in particular when the pipes are made of plastic material. More precisely, the sliding of the side surface of the pipes on the fastening ring scratches the side surface and alters its shape. As a result, the fins on the sealing ring do not fluid-tightly abut against the side surface of the respective pipe and, therefore, spillage and/or leakage of fluid may occur.  
         [0010]     In order to remove such drawback, couplings in which the sealing ring and the fastening ring present exchanged positions along the insertion/disconnection direction of the pipe are known. In this way, during insertion of each pipe, the respective side surface slides firstly on the sealing ring and then on the fastening ring; therefore, the fluid tightness provided by the coupling is optimal because the possible scratches on the side surface generated by the relative sliding between pipe and fins do not cooperate with the sealing ring.  
         [0011]     Such couplings are available in a first embodiment in which each locking member is fastened to the body of the coupling so as to lock, on opposite side of the respective fastening ring, the respective pipe in the predetermined locking position. Such first embodiment presents the drawback of not allowing the pipes to be disconnected from the respective conduits.  
         [0012]     In a second embodiment, each locking member is releasably constrained to the coupling body so as to be available in a first operative position, in which it locks the respective pipe in the predetermined locking position, and in a second operative position, in which it does not withhold the pipe in the predetermined locking position allowing the pipe itself to be disconnected.  
         [0013]     Each locking member is moved between the first and the second operative positions by means of a threaded connection arranged between each locking member and the coupling body.  
         [0014]     Operating the threaded connection requires the relative rotation of the releasing member with respect to the coupling itself according to a predetermined number of turns. Therefore, the disconnection of each pipe from the respective conduit is awkward in difficulty accessible spaces.  
       SUMMARY OF THE INVENTION  
       [0015]     It is the object of the present invention to construct a fast-fit coupling for a fluid circulation system, which allows the drawbacks related to the fast-fit couplings of the known type to be solved in a straightforward, inexpensive manner.  
         [0016]     The abovementioned object is achieved by the present invention in that it relates to a fast-fit coupling for a fluid circulation system as defined in the attached claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     For a better understanding of the present invention, it will now be described a preferred embodiment by way of non-limitative example, and with reference to the accompanying drawings, in which:  
         [0018]      FIGS. 1 and 2  show in axial section respective insertion positions of a pipe in a fast-fit coupling according to the invention;  
         [0019]      FIGS. 3 and 4  show in axial section respective disconnection positions of the pipe from the fast-fit coupling in  FIGS. 1 and 2 ;  
         [0020]      FIG. 5  shows a frontal view of two details in  FIG. 1 ;  
         [0021]      FIG. 6  is a section taken along line VI-VI in  FIG. 3 ; and  
         [0022]      FIG. 7  is a section taken along line VII-VII in  FIG. 2 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]     With reference to figures from  1  to  4 , it is indicated as a whole by  1  a fast-fit coupling for a fluid circulation system of which only a fluid conveying pipe  2  is shown.  
         [0024]     The coupling  1  is adapted to reciprocally and fluid-tightly connect a plurality of pipes  2 , and is defined by a hollow body  6  comprising a plurality of cylindrical conduits  3  (only one of which is shown) having respective axes A and adapted to be releasably engaged by respective pipes  2 .  
         [0025]     The description that follows will make reference, for simplicity&#39;s sake, without loosing in generality, to a single conduit  3  and to a single pipe  2 .  
         [0026]     The conduit  3  is open outwards through an opening  4  adapted to allow the pipe  3  to be inserted/disconnected according to respective connection directions I, D reciprocally opposite and arranged in use parallelly to axis A, and presents a shoulder  5  arranged on the opposite side of the opening  4  and recessed on an inner wall of the conduit  3  towards the axis A.  
         [0027]     The coupling  1  comprises a locking assembly  8  adapted to lock the pipe  2  in a predetermined position inside the conduit  3 , a sealing ring  10  adapted to fluid-tightly cooperate with a side surface  7  of the pipe  2  to prevent spillage of fluid, and an annular socket  11  presenting a recess  9  adapted to abut against the shoulder  5  and to define a stop position for the pipe  2  during insertion of the pipe  2  in the conduit  3  itself according to direction D.  
         [0028]     As shown in figures from  1  to  4 , the locking assembly  8 , the sealing ring  10  and the socket  11  are adapted to be accommodated inside the conduit  3  during the connection and use step of the pipe  2  (figures from  1  to  3 ), and are integrally extractable from the pipe  2  during the disconnection step of the pipe  2  itself from the conduit  4  ( FIG. 4 ).  
         [0029]     In greater detail, the locking assembly  8  comprises a fastening ring  12  provided with a plurality of circumferential fins  13  (only two of which are shown in figures from  1  to  4 ) adapted to be shifted and engaged by the pipe  2  during the connection of the pipe  2  itself, and a locking member  14  adapted to be releasably connected to the inner surface of the conduit  3  so as to cooperate with the fins  13  to prevent the pipe  2  from being pulled out from the conduit  3  in direction opposite to the direction of insertion.  
         [0030]     More precisely, the fastening ring  12  extends about an axis coinciding in use with axis A and presents opposite openings of axial ends  50 ,  51  adapted to be crossed in use by pipe  3 .  
         [0031]     The fastening ring  12  is adapted to be inserted inside the conduit  3  so that the opening  51  is adjacent to the socket  11  and the opening  50  faces an annular spacer  42 , which is fittable inside the coupling  3  in a position axially interposed between the sealing ring  10  and the fastening ring  12 .  
         [0032]     The fastening ring  12  further comprises a discoidal body  15  adapted to be fastened, at an edge  16 , onto the inner wall of the conduit  3 , and protrudingly carrying the fins  13 , at an edge  17  radially more internal with respect to the edge  16 .  
         [0033]     More specifically, the fins  13  extend from the edge  17  and obliquely converge towards the axis of the fastening ring  12 . The fins  13  also extend from the fastening ring  12  on opposite side of the opening  50 . In this way, during insertion of the pipe  2  in the conduit  4  in the direction of the shoulder  5 , the fins  13  can shift towards the shoulder  5 , while during disconnection of the pipe  2  in direction of the opening  4 , the fins  13  move integrally with the pipe  2  itself inside the conduit  3 .  
         [0034]     Advantageously, the sealing ring  10  is axially interposed between the fastening ring  12  and the locking member  14 . In this way, in the case of pipes  2  made of plastic material, the scratches provided on the surface of the pipes  2  during sliding thereof on the fins  13  of the fastening ring  12  do not cooperate with the sealing ring  10 . Therefore, the possible fluid leakage along such scratches cannot pass through the sealing ring  10 .  
         [0035]     The locking member  14  has an annular shape and presents opposite openings  18 ,  19  of axial ends adapted to allow the crossing of the pipe  3 .  
         [0036]     The locking member  14  is adapted to be coaxially fixed inside the conduit  3  at the opening  18 , and to be accommodated with clearance inside a thickening  40  of the conduit  3  at an intermediate portion  41  between the openings  18  and  19 , and to partially project from the conduit  3  to allow a pipe  2  to be inserted inside the conduit  3  through the opening  19 .  
         [0037]     Furthermore, the locking member  14  can be releasably coupled to the body  6  of the coupling  1 . In this way, when the locking member  14  is fastened to the body  6  of the coupling  1  ( FIGS. 1 and 2 ), the pipe  2  remains fastened into the conduit  3  in a predetermined locking position by the fins  13  and the locking member  14 .  
         [0038]     Otherwise, when the locking member  14  is disconnected from the body of the coupling  1  ( FIG. 3 ), the pipe  2  can slide towards the opening  4  and therefore can be extracted in direction D.  
         [0039]     More precisely, the locking member  14  and the body  6  can be coupled so as to be reciprocally inserted/disconnected by a relative rotation of the locking member  14  and the body  6  themselves.  
         [0040]     Advantageously, the relative rotation of the locking member  14  and the body  6  occurs for an arc less than ninety degrees.  
         [0041]     In greater detail, the coupling  1  and the locking member  14  are connected together with a pair of bayonet mounts  20  (only one of which is shown in  FIGS. 1 and 2 ) symmetrically arranged with respect to the insertion/disconnection direction of the pipe  2  in the conduit  3 .  
         [0042]     Each bayonet mount  20  comprises a seat  22  made through the body  6 , and a locator member  21  externally protruding from the portion  41  of the locking member  14  and having shape complementary to the seat  22 .  
         [0043]     More precisely, the locator member  21  and the seat  22  are reciprocally coupled by determining the rotation of the locator member  21  relatively to the seat  22  inside the thickening  40  according to two reciprocally opposite angular directions.  
         [0044]     Each seat  22  is circumferentially delimited by a pair of surfaces  23 ,  24  parallel to the axis A and is axially delimited by a pair of surfaces  25 ,  26  extending between the surfaces  23 ,  24 .  
         [0045]     In particular, the surface  25  is facing towards the opening  4  and lays on a plane orthogonal to the surfaces  23 ,  24 .  
         [0046]     The surface  26  comprises a central groove  27  and a pair of side segments  28 ,  29  converging from respective surfaces  23 ,  24  towards the groove  27  itself.  
         [0047]     The groove  27  has an arc of circumference shape and is joined, on opposite sides, to the segment  28  and to the segment  29 .  
         [0048]     The segment  28  connects one axial end facing the opening  4  of the surface  23  at the recess  27 , while the segment  29  connects one axial end facing the opening  4  of the surface  24  at the recess  27  itself.  
         [0049]     The locator member  21  is circumferentially delimited by two pairs of surfaces  32 ,  33  parallelly extending to axis A and axially delimited by a pair of surfaces  34 ,  35  extending between the surfaces  32 ,  33 .  
         [0050]     In particular, the surface  34  extends towards the opening  4  and lays on a plane orthogonal to the surfaces  32 ,  33 .  
         [0051]     The surface  35  comprises a central ridge  36  adapted to slide on one of the segments  28 ,  29  so as to engage the groove  27  and withhold the locator member  21  in the seat  22 , and a pair of side segments  37 ,  38  converging from respective surfaces  32 ,  33  towards the ridge  36  and adapted to cooperate respectively with the segments  28 ,  29  during the coupling/uncoupling of the locator member  21  and the seat  22 .  
         [0052]     In particular, the ridge  36  presents an arc of circumference shape and is joined, by its opposite sides, to segments  37 ,  38 .  
         [0053]     The segment  37  connects one axial end facing the opening  19  of the surface  32  at the ridge  36 , while the segment  38  connects one axial end facing the opening  19  of the surface  33  at the ridge  36 .  
         [0054]     In use and with reference to figures from  1  to  3 , the conduit  3 , proceeding from the aperture  4  to the shoulder  5 , coaxially accommodates the locking member  14 , the sealing ring  10 , the spacer  42 , the fastening ring  13  and the socket  11 .  
         [0055]     The bayonet mounts  20  also couple the locking member  14  and the body  6  so as to prevent the sliding parallelly to the axis A of the locking member  14  with respect to the body  6 .  
         [0056]     More precisely, such coupling occurs by engaging each locator member  21  in the respective seat  22 . In particular, each ridge  36  is inserted in the respective groove  27  and each segment  28 ,  29  cooperates with the respective segments  37 ,  38 .  
         [0057]     During the insertion step ( FIG. 2 ), the pipe  2  is coaxially inserted inside the conduit  3  to abut against the socket  11 . In this step, the side surface  7  of the pipe  2  sequentially slides inside the locking member  14 , the sealing ring  10  and the spacer  42 ; then, the side surface  7  of the pipe  2  shifts the fins  13  of the fastening ring  12  towards the socket  11 ; finally, the side surface  7  of the pipe  2  slides inside the socket  11  until it stops against the recess  9  of the socket  11  itself.  
         [0058]     At the end of such insertion step ( FIG. 2 ), the pipe  2  remains locked in a predetermined position inside the conduit  3  because it is withheld, on its opposite sides, by the fins  13  and the locking member  14 , which is fastened to the body  6  by means of the bayonet mounts  20 .  
         [0059]     The pipe  2  is also fluid-tightly withheld inside the conduit  3  thanks to the action of the sealing ring  10 , which fluid-tightly cooperates with the side surface  7  of the pipe  3  itself.  
         [0060]     To obtain the disconnection of the pipe  2  from the conduit  3  ( FIGS. 3 and 4 ), it is sufficient to exert a torque on the locking member  14  so as to firstly determine the release of each ridge  36  from the respective groove  27  and, then, the rotation of the locking member  14  with respect to the body  6  inside the thickening  40  for an arc less than ninety degrees ( FIG. 3 ). At the end of such rotation, the pipe  2  is no longer locked by the locking member  14  and may be disconnected in direction I of the conduit  3  through the opening  4  ( FIG. 4 ).  
         [0061]     Since the seat  33  presents two segments  28 ,  29  converging towards the recess  27 , the release of the locking member from the body  1  may be obtained by causing the relative rotation of the locking member  14  with respect to the body  6  in two reciprocally opposite angular directions.  
         [0062]     As shown in  FIG. 4 , during the disconnection step of the conduit  3 , the pipe  2  drags the locking member  14 , the sealing ring  10 , the spacer  42  and the fastening ring  17 , which may be recovered by cutting the pipe  3  itself and extracting them from the pipes  3 .  
         [0063]     From an examination of the features of the coupling  1  made according to the present invention, the advantages that it allows to obtain are apparent.  
         [0064]     In particular, the fast-fit coupling  1  allows the pipe  2  to be disconnected from the conduit  3  by turning the locking member  14  with respect to the body  6  for an arc less than ninety degrees.  
         [0065]     Therefore, such rotation, extending for a relatively small arc, may be easily performed also in small, restricted spaces.  
         [0066]     It is finally apparent that changes and variations can be made to the fast-fit coupling  1  constructed according to the present invention without departing from the scope of protection of the claims.  
         [0067]     In particular, the coupling  1  and the locking member  14  may be connected together by means of a single bayonet mount  20 .