Abstract:
The invention relates to fast couplings for connecting hoses, particularly for domestic irrigation. A fast coupling is formed by a first body and a second body reciprocally connected by inserting first lugs projecting from the second body in first slots made on the first body. A male connector is locked inside the fast coupling by radially pressing an end of the male connector with a torus-shaped elastic element. Unlocking the second body from the first body causes the automatic ejection of the mail connector.

Description:
This application claims benefit under 35 U.S.C. §119 of Italian Application No. PR2002A000036, filed Jun. 24, 2002. 
   FIELD OF THE INVENTION 
   The subject matter of the present invention is a fast coupling for irrigation systems, particularly domestic irrigation systems. 
   BACKGROUND OF THE INVENTION 
   Couplings adapted to connect two hoses or temporarily connect domestic-type irrigation elements for gardens and kitchen gardens are already known and have been manufactured. Designers have always tried to combine practicality and low manufacturing cost in these couplings, these characteristic are deemed critical in order to sell as many couplings as possible. 
   Prior art couplings are capable to meet design goals, however at the expense of a rather complex structure; particularly, this complexity regards both the number of components, sometimes considerable, and the same inventive idea which shows some drawbacks regarding the usability when it is put into practice 
   Document U.S. Pat. No. 5,797,626 describes a fast coupling between two hoses wherein a male connector is connected to a central body by radially buckling an elastic element upon pressing said connector along the longitudinal axis, said male connector being previously completely inserted in the elastic element. 
   The number of components making up said coupling is so great that there are two drawbacks: high cost and recurrent failures. 
   SUMMARY OF THE INVENTION 
   A first object of the present invention is a fast coupling made up by few components. 
   Another object is a coupling showing a better practicality than known couplings. 
   Particularly, the fast coupling for connecting two hoses, specifically intended to be used for domestic irrigation, comprising: at least one body adapted to be connected to a male connector, characterized by the fact that the coupling comprises:
         a first inner body and second outer body coaxial with respect to each other, the first and second bodies being partially slidable with respect to each other along a common longitudinal axis; said first and second bodies being hollow along said longitudinal axis and being detachably locked together via reciprocally cooperative connecting and disconnecting means; said second body being adapted to be connected to the male connector;   an elastic torus-shaped element housed inside the second body, said elastic element being adapted to lock said male connector;   an elastic compression element longitudinally located between said first and second bodies; said elastic compression element being adapted both to instantaneously disconnect the male connector from the second body and easily release the first body from said second body;   said first and second body being detachably locked when the fast coupling is in an operative state.       

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other characteristics will be better understood by the following description of a preferred embodiment of the present invention shown in an illustrative and non-limiting way in the drawings, wherein: 
       FIG. 1  is a prospective exploded view of elements making up the fast coupling with a male connector, 
       FIG. 2  is a section of the first body of the fast coupling, 
       FIG. 3  is a section of the second body of the fast coupling, 
       FIG. 4  is a section view of the fast coupling connected to the male connector, 
       FIG. 5  is the same view of  FIG. 4  except for the male connector is disconnected from the fast coupling. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to figures,  1  shows a fast coupling made up by a first body  2  adapted to be connected, by its first thread  3 , to a first hose not shown, and a second body  4 ; both said bodies being substantially cylindrical, coaxial to each other, the second body being insertable in the first body. 
   Both bodies are hollow along a longitudinal axis of symmetry A—A, an inner cavity in the body  1  being adapted to receive a water flow being shown at  5 . Second body  4  partially slides into first body  2  along axis A—A. 
   A circumferential housing  6  is defined inside first body  2 . A first end of a cylindrical compression spring  7  abuts a first step  8  inside first body  2 , a second end abuts a second step  9  inside second body  2 . 
   First body  2  is provided with an inner circumferential shoulder  10  defined between circumferential housing  6  and inner cavity  5 . A torus-shaped spring  11  is received inside second body  4 , particularly inside its inner portion  12  that is hemispherical in the cross-section and shrinks towards second body end, said end being provided with an opening  13  symmetrical to axis A—A. 
   Said opening  13  is shaped to fit to the outer profile of an end  14  of a male connector  15  designed to be connected to a second hose, not shown, by a second thread  16 . 
   As specifically shown in  FIGS. 4 and 5  illustrating the fast coupling  1 , torus-shaped spring  11  is located inside a housing  17  defined by the inner part  12 , the circumferential shoulder  10  and the outer surface of end  14 . 
   The outer circumference of first body  2  is provided with two first flexible elements  18  and two first slots  19 ; each first slots being in between said two first flexible elements. Said first flexible elements are made by cutting the circumferential surface of first body  2 , two second slots  20  are simultaneously cut in the two first flexible elements  18  respectively. 
   Second body  4  is provided along its outer circumference with second flexible elements  21  and two third flexible elements  22 ; each third flexible elements being in between said two second flexible elements. Each said second flexible elements and each said third flexible elements are provided with a first lug  23  and a second lug  24  respectively, both lugs facing radially outwardly from the second body. 
   The width of two first lugs  23  is scarcely less than the width of the two slots  19 , while second lugs  24  are shaped so that they can cooperate with two slots  20 . 
   The outer surface of each second flexible elements  21  have a portion  25  shaped as an inclined plane. 
   The operation of the device of the present invention will be described in the following referring to the numbers in the figures. 
   The user grasps first body  2  and inserts end  14  of male connector  15  in opening  13  until the latter abuts second body  4 . Then the user keeps pushing the male connector against second body  4  so that the latter slides inside the first body  2  along the longitudinal axis A—A; during this step, the top of lugs  24  slides along the inner surface of first body  2  compressing cylindrical spring  7 . 
   The sliding step is carried on until first lugs  2  enter second slots  20  by a snap due to flexibility of second elements  21  and perceived by the user; said insertion prevents second body from disconnecting. 
   Said sliding step makes torus-shaped spring  11  to shrink radially because circumferential shoulder  10  pushes it toward the smaller portion of hemispherical housing  17 , in this way torus-shaped spring is clamped on the outer surface of end  14  of male connector  15  which in turn is fastened to fast coupling  1 . 
   When user wants to disconnect male connector  15  from fast coupling  1 , he/she can do that using just one hand; indeed after having grasped first body  2 , he/she presses first flexible elements  18  with the same hand, said pressure causes the inner surface of said first elements to press portion  25  of second flexible elements  21  which in turn are lowered releasing lugs from respective second slots  20 . Cylindrical spring  7  instantaneously moves second body  4  away from first body  2 , so that torus-shaped spring  11  can radially expand because it is contained in the portion of inner space  12  having the largest diameter and releases its radial pressure on male connector  15 . The snap of cylindrical spring  7  automatically drives out said male connector from the second body  4 . 
   Therefore elements  18 ,  20 ,  21 , and  24  form connecting and releasing means. 
   It is to be noted that when the user introduces male connector  15  in the opening  13 , the first and second body forming the fast coupling  1  are already reciprocally connected, as shown in  FIGS. 4 and 5 , said connection being established before the use of said fast coupling by the insertion of lugs  23  in first slots  19 . Said insertion is made in the following way: when the first body  2  and second body  4  are to be connected, second body  4  is pushed inside first body  2  until third flexible elements  22  come at first slots  19  so that the lugs  23  enter said slots; now the two bodies are connected to each other so that one of the bodies can slide with respect to the other by an amount equal to the length of slots  19 . 
   The two bodies can be disconnected by pressing simultaneously the two third flexible elements  22  using a sharp tool capable of penetrating inside first slots  19 ; said step which is necessary to disconnect second lugs  23  from first slots  19  is a safety feature which makes almost impossible an unintentional disconnection of said first and second body during the use of fast coupling  1 . 
   A first advantage of the fast coupling of the present invention consists in that it is made up by few components, in this way the manufacturing cost, the possibility of breaks and failure are kept low during the use of fast coupling  1 . 
   Another advantage is that the simplicity and practicality of use are improved in fact the male connector  15  can be disconnected effortlessly from the fast coupling of the present invention by just one hand so that the other hand can be used for other operations.