Elastic element for a device for dispensing fluids or mixtures and method and mould for making said elastic element

Abstract

The invention concerns an elastic element ( 100 ) made of a plastic material for a device ( 1 ) for dispensing fluids (L), comprising a tubular body ( 129 ) that develops around a main longitudinal axis (X), comprising a main portion that develops according to a spiral-shaped pattern and extends longitudinally between a first end portion ( 100 a ) and a second end portion ( 100 b ) opposite the first end portion ( 100 a ). One of the first and second end portions comprises a first projection ( 151 ) extending from the internal surface of the tubular body ( 129 ) towards the inner space defined by the tubular body ( 129 ). The invention furthermore concerns a method for making an elastic element ( 100 ) through an injection moulding process, a mould ( 200 ) for making an elastic element ( 100 ).

1 . An elastic element ( 100 ) made of a plastic material for a device ( 1 ) for dispensing fluids (L), comprising a tubular body ( 129 ) that develops around a main longitudinal axis (X) having a longitudinal direction, said tubular body ( 129 ) comprising an internal surface ( 150 ), an inner space defined by said tubular body ( 129 ) and at least one main portion that develops according to a spiral-shaped pattern and extends along the longitudinal direction between a first end portion ( 100   a ) and a second end portion ( 100   b ) opposite said first end portion ( 100   a ), wherein at least one of said first and second end portions comprises at least one first projection ( 151 ) extending from the internal surface of said tubular body ( 129 ) towards the inner space. 
     
     
         2 . The elastic element ( 100 ) according to  claim 1 , wherein said at least one first end portion ( 100   a ) comprises a tubular portion with a substantially cylindrical inner wall ( 150 ) that extends along the longitudinal direction from said main portion developing according to a spiral-shaped pattern, and in that said at least one first projection ( 151 ) extends from said substantially cylindrical inner wall ( 150 ). 
     
     
         3 . The elastic element ( 100 ) according to  claim 1 , wherein said at least one first projection ( 151 ) extends along a direction that is substantially perpendicular to said main longitudinal axis (X). 
     
     
         4 . The elastic element ( 100 ) according to  claim 1 , wherein said at least one first end portion ( 100   a ) comprises a plurality of first projections ( 151 ) arranged at substantially regular intervals from one another along said internal surface ( 150 ) of said tubular body. 
     
     
         5 . The elastic element ( 100 ) according to  claim 1 , wherein said second end portion ( 100   b ) of said tubular body ( 129 ) opposite said first end portion ( 100   a ) comprises at least one second projection ( 153 ) extending along a direction that is substantially parallel to said main longitudinal axis (X). 
     
     
         6 . The elastic element ( 100 ) according to  claim 5 , wherein said at least one second projection ( 153 ) extends from an end wall that is substantially perpendicular to said main longitudinal axis (X) towards the outside of said tubular body ( 129 ). 
     
     
         7 . The elastic element according to  claim 6 , wherein said end wall is in the shape of an annulus. 
     
     
         8 . A method for making an elastic element ( 100 ) via an injection molding process, said method comprising the following steps:
 providing a mold ( 200 ) suitable for injection molding comprising a hollow die ( 204 ) and a male punch ( 206 ) rotatably arranged inside said die ( 204 ) in such a way as to define an interspace (I) in a shape corresponding to that of an elastic element ( 100 ) having first projections ( 151 ) and second projections ( 153 ) between said hollow die ( 204 ) and said male punch ( 206 );   injecting plastic material in a pasty state into said interspace (I); and   removing said male punch ( 206 ) by rotating it on its longitudinal axis,   wherein during rotation of said punch ( 206 ) at least one of said first projections and said second projections ( 151 ,  153 ) of said elastic element ( 100 ) becomes engaged in a corresponding seat created in said mold ( 200 ), so that said elastic element ( 100 ) cannot be rotated by said punch ( 206 ).   
     
     
         9 . The method according to  claim 8 , wherein said mold ( 200 ) comprises a housing bush ( 207 ) for said male punch ( 206 ), in which said male punch ( 206 ) is rotatably accommodated, and in that during rotation of said male punch ( 206 ) at least one of said first projections ( 151 ) becomes engaged in a corresponding seat provided in said housing bush ( 207 ). 
     
     
         10 . The method according to  claim 9 , wherein said mold ( 200 ) comprises an injection unit ( 205 ) suited to be positioned proximal to said interspace (I) so as to allow a plastic material in the pasty state to be injected into said interspace (I), and during rotation of said punch ( 206 ) at least one of said second projections ( 153 ) becomes engaged in a corresponding seat provided in said injection unit ( 205 ). 
     
     
         11 . A mold ( 200 ) suitable for making an elastic element ( 100 ) according to  claim 1 , said mold ( 200 ) comprising at least one rotatable male punch ( 206 ) defining a longitudinal rotation axis, and at least one hollow die ( 204 ), said at least one rotatable male punch ( 206 ) and said at least one hollow die ( 204 ) being suited to be mutually positioned so as to define an interspace (I) in a shape corresponding to that of an elastic element ( 100 ), wherein said mold ( 200 ) comprises at least one cavity suited to receive a portion of a plastic material in a pasty state intended to be used to make at least one of said first projections and said second projections ( 151 ,  153 ), said at least one cavity thus defining at least one seat in which at least one of said first projections and said second projections ( 151 ,  153 ) can become engaged during rotation of said punch ( 206 ) around said longitudinal rotation axis. 
     
     
         12 . The mold according to  claim 11 , wherein said mold ( 200 ) comprises at least one housing bush ( 207 ) in which said male punch ( 206 ) is rotatably accommodated, and said at least one cavity is defined by said housing bush ( 207 ), said at least one cavity thus defining a seat in which at least one of said first projections ( 151 ) can become engaged during rotation of said punch ( 206 ) around said longitudinal rotation axis. 
     
     
         13 . The mold according to  claim 12 , wherein said mold comprises an injection unit ( 205 ) suited to be positioned at the level of said interspace (I) so as to allow a plastic material in a pasty state to be injected into said interspace (I), and in that said injection unit ( 205 ) comprises at least one second cavity suited to accommodate a portion of a plastic material in a pasty state intended to be used to make at least one of said second projections ( 153 ), said at least one second cavity thus defining a seat in which at least one of said second projections ( 153 ) can become engaged during rotation of said punch ( 206 ) around said longitudinal rotation axis. 
     
     
         14 . The mold according to  claim 11 , wherein said die is formed by two complementary portions ( 204   a,    204   b ) suited to be translated in two opposite senses of translation along a direction of translation that is substantially perpendicular to the longitudinal rotation axis of said male punch ( 206 ). 
     
     
         15 . The mold according to  claim 11 , wherein said mold ( 200 ) comprises a movable portion ( 203 ) suited to be translated in two opposite senses of translation along a direction that is substantially parallel to said longitudinal rotation axis of said male punch ( 206 ).