Safety cap for a liquid reservoir for a motor vehicle

Abstract

A safety cap (10), for a motor vehicle fluid reservoir (14), is configured to be attached and fixed to a neck (12) of the reservoir. The cap includes a screwing cover (16) with a first screw thread (16ba), and a safety cell (18) configured to allow passage of gas between the interior and the exterior of the reservoir, when the cap is fixed to the neck and when a pressure difference between the interior and the exterior of the reservoir is greater or less than at least one predetermined threshold value. The cap includes a ring (20) with structure (30, 30a, 32) for fixing to the neck and a second screw thread (22) to cooperate with the first screw thread. The cell is at least partly housed in the neck and surrounded by the cover and/or the ring when the cap is fixed on the neck.

1 . An assembly comprising:
 a fluid reservoir ( 14 ,  114 ), for a motor vehicle, and a cap ( 10 ,  110 ),   said reservoir comprising a neck ( 12 ,  112 ) equipped with a screw thread ( 22 ,  122 ,  222 ),   said cap comprising a screwing cover ( 16 ,  116 ) comprising a screw thread ( 16   ba ,  116   ba ), and a safety cell ( 18 ,  118 ) configured to allow the passage of gas between an interior of the reservoir and an exterior of the reservoir, when the cap is screwed onto said neck and when a pressure difference between the interior and the exterior of the reservoir is greater or less than at least one predetermined threshold value,   wherein said safety cell comprises an annular seal ( 74 ,  174 ) which is configured to seal against an annular wall ( 44 ,  144 ) of said neck when the cap is screwed onto the neck by cooperation of the screw thread of said neck and the screw thread of the cover, and which annular seal is further configured to collaborate with the annular wall by bearing with elastic deformation in order to provide a stable transport position for said assembly in which the cap is premounted on the neck and the screw thread of said neck and the screw thread of the cover are not yet cooperating with one another.   
     
     
         2 . The assembly as claimed in  claim 1 , in which said annular seal ( 74 ,  174 ) is housed in an outer annular groove of said cell ( 18 ,  118 ). 
     
     
         3 . The assembly as claimed in  claim 1 , in which said annular seal ( 74 ,  174 ) is housed in an outer annular groove of a substantially cylindrical body ( 64 ) of said cell, which is intended to be surrounded by said annular wall ( 44 ,  144 ). 
     
     
         4 . The assembly as claimed in  claim 1 , in which said neck ( 12 ,  112 ) is of the coaxial double-walled type and comprises an outer annular wall bearing said screw thread of said neck ( 22 ,  122 ,  222 ) and the annular wall ( 44 ,  144 ) configured to cooperate with said seal ( 74 ,  174 ) is an inner annular wall of said neck. 
     
     
         5 . The assembly as claimed in  claim 4 , in which the annular wall ( 44 ,  144 ) at its upper end has a free annular edge ( 46 ,  146 ) which is crenellated and exhibits an alternation of solid parts ( 46   a ,  146   a ) and of recessed parts ( 46   b ,  146   b ) which define spaces for the passage of gas in a radial direction. 
     
     
         6 . The assembly as claimed in  claim 5 , in which said seal ( 74 ,  174 ) bears radially against said free annular edge ( 46 ,  146 ) when the cap ( 10 ,  110 ) is in the stable transport position. 
     
     
         7 . (canceled) 
     
     
         8 . The assembly as claimed in  claim 6 , in which said annular wall comprises at least two portions ( 146   aa ,  146   ab ,  146   ac ) of different inner diameters, which are each able to cooperate with said annular seal ( 74 ,  174 ). 
     
     
         9 . The assembly as claimed in  claim 8 , in which the free annular edge ( 146 ) comprises a first portion ( 146   aa ) of inner diameter H 1  and the rest of the inner annular wall ( 144 ) comprises another portion of inner diameter H 3  which is less than H 1 . 
     
     
         10 . The assembly as claimed in  claim 9 , in which the free annular edge ( 146 ) comprises a second portion ( 146   ab ) of inner diameter H 2 , between said first and other portions, where H 2  is comprised between H 3  and H 1 . 
     
     
         11 . A safety cap ( 10 ,  110 ) for a fluid reservoir ( 14 ,  114 ) of a motor vehicle, said cap being configured to be attached and fixed to a neck ( 12 ,  112 ) of said reservoir, said cap comprising:
 a screwing cover ( 16 ,  116 ) comprising a first screw thread ( 16   ba ,  116   ba ), and   a safety cell ( 18 ,  118 ) configured to allow the passage of gas between an interior of the reservoir and an exterior of the reservoir, when the cap is fixed to said neck and when a pressure difference between the interior and the exterior of the reservoir is greater or less than at least one predetermined threshold value,   
       wherein the cap further comprises:
 a ring ( 20 ,  120 ) comprising means ( 30 ,  30   a ,  32 ,  128 ,  129 ) for fixing to said neck and a second screw thread ( 22 ,  122 ) configured to cooperate with said first screw thread, said cell being at least partly housed in the neck and surrounded by said cover and/or said ring when the cap is fixed on said neck, wherein said ring ( 20 ,  120 ) comprises an inner annular surface ( 20   aa ,  120   aa ) intended to surround, with clearance, an outer annular surface ( 44   a ,  144   a ) of said neck ( 12 ,  112 ) so as to define a space ( 58 ,  158 ) for the passage of gas between the ring and the neck. 
 
     
     
         12 . The cap ( 10 ,  110 ) as claimed in  claim 1 , in which said ring ( 20 ,  120 ) comprises ribs ( 26 ,  126 ) projecting from said inner annular surface ( 20   aa ,  120   aa ) and able to cooperate by bearing and/or sliding with said outer annular surface ( 44   a ,  144   a ) of said neck ( 12 ,  112 ). 
     
     
         13 . The cap ( 10 ,  110 ) as claimed in  claim 12 , in which said ring ( 20 ,  120 ) comprises means ( 30 ,  30   a ,  32 ,  128 ,  129 ) for fixing to said neck ( 12 ,  112 ) by bayonet effect and/or elastic snap-fastening. 
     
     
         14 . The cap ( 10 ) as claimed in  claim 13 , in which said ring ( 20 ) comprises inner annular rim sectors ( 30   a ) which are intended to cooperate by bayonet effect with outer annular rim sectors ( 50   a ) of said neck ( 12 ). 
     
     
         15 . The cap ( 10 ) as claimed in  claim 14 , in which said inner annular rim sectors ( 30   a ) of said ring ( 20 ) bear first elastic snap-fastening means ( 32 ) intended to cooperate with complementary elastic snap-fastening means ( 52 ) of said outer annular rim sectors ( 50   a ) of said neck ( 12 ). 
     
     
         16 . The cap ( 10 ) as claimed in  claim 15 , in which said ring ( 20 ) comprises circumferential through-slots ( 28 ) extending along and in proximity to said inner annular rim sectors ( 30   a ) so as to provide them with a certain degree of flexibility. 
     
     
         17 . The cap ( 110 ) as claimed in  claim 13 , in which said ring ( 120 ) comprises slideways ( 128 ) configured to cooperate with rails ( 149 ) of said neck ( 112 ) in order to produce guiding by axial sliding when mounting said ring on said neck. 
     
     
         18 . The cap ( 110 ) as claimed in  claim 17 , in which at least one of said slideways ( 128 ) bears first elastic snap-fastening means ( 129 ) intended to cooperate with complementary elastic snap-fastening means ( 150 ) of at least one of said rails ( 149 ). 
     
     
         19 . A fluid reservoir ( 14 ,  114 ) for a motor vehicle, said reservoir comprising:
 a neck ( 12 ,  112 ) on which there is intended to be attached and fixed a cap ( 10 ,  110 ), wherein said neck comprises either:
 (a) a cylindrical wall ( 44 ) comprising outer annular rim sectors ( 50   a ), said outer annular rim sectors ( 50   a ) of said cylindrical wall ( 44 ) bear elastic snap-fastening means ( 52   a ), 
 or 
 (b) a cylindrical wall ( 144 ) and an annular row of rails ( 149 ) projecting from an outer cylindrical surface of this cylindrical wall, said rails being substantially parallel to one another and to an axis (C) of revolution of this cylindrical wall, wherein at least some of said rails ( 149 ) bear elastic snap-fastening means ( 150 ). 
   
     
     
         20 - 23 . (canceled) 
     
     
         24 . The reservoir ( 14 ,  114 ) as claimed in  claim 19 , in which said cylindrical wall ( 44 ,  144 ) comprises a crenellated free annular edge ( 46 ,  146 ) comprising solid parts ( 46   a ,  146   a ) alternating with recessed parts ( 46   b ,  146   b ) for the passage of gas. 
     
     
         25 . The reservoir ( 14 ,  114 ) as claimed in  claim 24 , in which said neck ( 12 ,  112 ) comprises an annular shoulder for the axial bearing of said cap ( 10 ,  110 ) and onto which a gas passage orifice ( 56 ,  156 ) can open. 
     
     
         26 . The reservoir ( 14 ,  114 ) as claimed in  claim 25 , comprising a gas passage duct ( 54 ,  154 ) defining said orifice ( 56 ,  156 ) and extending substantially over the height of said reservoir. 
     
     
         27 - 29 . (canceled) 
     
     
         30 . An assembly, comprising:
 a reservoir ( 14 ,  114 ) and a cap ( 10 ,  110 );   wherein the reservoir includes a neck ( 12 ,  112 ) with an outer annular surface ( 44   a ,  144   a );   wherein the cap includes:
 a screwing cover ( 16 ,  116 ) comprising a first screw thread ( 16   ba ,  116   ba ), 
 a safety cell ( 18 ,  118 ) configured to allow the passage of gas between an interior of the reservoir and an exterior of the reservoir, when the cap is fixed to said neck and when a pressure difference between the interior and the exterior of the reservoir is greater or less than at least one predetermined threshold value, 
 a ring ( 20 ,  120 ) comprising means ( 30 ,  30   a ,  32 ,  128 ,  129 ) for fixing to said neck and a second screw thread ( 22 ,  122 ) configured to cooperate with said first screw thread, 
 wherein said safety cell is at least partly housed in the neck and surrounded by said cover and/or said ring when the cap is fixed on said neck, wherein said ring ( 20 ,  120 ) comprises an inner annular surface ( 20   aa ,  120   aa ) to surround, with clearance, the outer annular surface ( 44   a ,  144   a ) of said neck ( 12 ,  112 ) so as to define a space ( 58 ,  158 ) for the passage of gas between the ring and the neck; 
   wherein the cap is either:
 premounted on said neck ( 12 ,  112 ), said cap being held on said neck only by the cooperation between an annular seal ( 74 ,  174 ) and a cylindrical wall ( 44 ,  144 ) of the neck, 
 or 
 fixed to said neck by bayonet effect and/or elastic snap-fastening. 
   
     
     
         31 . A motor vehicle, comprising at least one assembly as claimed in  claim 30 .