Sealing cap

Abstract

The invention relates to a pressure cap ( 11 ) for openings in tanks, particularly in motor-vehicle radiators, which has an internal cap component ( 14 ) that is provided with at least one flow connection between the inside and the outside of the tank, and with a valve arrangement ( 15 ) for releasing and blocking the flow connection. The said valve arrangement ( 15 ) has a first and a second valve body ( 17, 18 ) that can be moved back and forth. The first valve body ( 17 ) is biased in the direction of the inside of the tank against a first sealing seat ( 24 ) on the second valve body ( 18 ), which is pressed against a second sealing seat ( 32 ) on the interior cap component ( 14 ). Furthermore, the first and second valve bodies ( 17, 18 ) can be lifted when a respective threshold value of the inside tank pressure is exceeded and the flow connection ( 50, 51 ) between the inside and the outside of the tank is released. To simplify the manufacture and installation of the pressure cap and also to improve the hysteresis behaviour, inside the second valve body ( 18 ) a third valve body ( 19 ) is placed, between which and the second valve body ( 18 ) a first flow connection ( 50 ), designed in that section as a throttle gap ( 47 ), is provided between the inside of the tank and the first valve body ( 17 ).

What is claimed is:  
     
         1 . Pressure cap ( 11 ,  111 ) for openings in tanks, particularly in motor-vehicle radiators, with an internal cap component ( 14 ,  114 ) that is provided with at least one flow connection between the inside and the outside of the tank, and with a valve arrangement ( 15 ,  115 ) for releasing and blocking the flow connection, whereby the said valve arrangement ( 15 ,  115 ) has a first and a second valve body ( 17 ,  118 ;  18 ,  118 ) that can be moved back and forth, whereby the first valve body ( 17 ,  117 ) is biased in the direction of the inside of the tank against a first sealing seat ( 24 ,  124 ) on the second valve body ( 18 ,  118 ), which is pressed against a second sealing seat ( 32 ,  132 ) on the interior cap component ( 14 ,  114 ), and whereby the first and second valve bodies ( 17   117 ;  18 ,  118 ) can be lifted when a respective threshold value of the inside tank pressure is exceeded and the flow connection ( 50 ,  150 ;  51 ,  151 ) between the inside and the outside of the tank is released, 
 characterized in that inside the second valve body ( 18 ,  118 ) a third valve body ( 19 ,  119 ) is placed, between which and the second valve body ( 18 ,  118 ) a first flow connection ( 50 ,  150 ), designed in that section as a throttle gap ( 47 ,  147 ), is provided between the inside of the tank and the first valve body ( 17 ,  117 ),    that said valve body ( 19 ,  119 ) is movable between one end position opening the first flow connection ( 50 ,  150 ) and the other end position closing it when a second threshold value of the inside radiator pressure is reached or when a dynamic pressure occurs due to the presence of a liquid medium,    that the first valve body ( 17 ,  117 ) is lifted off the second valve body ( 18 ,  118 ) when a first threshold value is exceeded and comes to bear again on same after the flow connection ( 50 ,  150 ) closes, and that the second valve body ( 18 ,  118 ) is lifted off the second sealing seat ( 32 ,  132 ) on the interior cap component ( 14 ,  114 ) while releasing a second flow connection ( 51 ,  151 ) between the inside and the outside of the radiator when a third threshold value of the inside radiator pressure is exceeded, which is higher than the first and the second threshold value of the inside radiator pressure and also higher than the dynamic pressure.    
     
     
         2 . Pressure cap according to  claim 1 , characterized in that the third valve body ( 19 ,  119 ) is held axially movable inside a concentric recess ( 37 ,  137 ) of the second valve body ( 18 ,  118 ), whereby said recess is in communication with the inside of the radiator.  
     
     
         3 . Pressure cap according to  claim 1  or  2 , characterized in that the third valve body ( 19 ,  119 ) in the second valve body ( 18 ,  118 ) is biased by a second spring ( 46 ,  146 ) in the direction of its opening position that is supported by the second valve body.  
     
     
         4 . Pressure cap according to at least one of  claims 1  to  3 , characterized in that a third sealing seat ( 43 ,  143 ) on the third valve body ( 19 ,  119 ) is added to an axially inward pointing annular sealing surface ( 39 ,  139 ) of the second valve body ( 18 ,  118 ).  
     
     
         5 . Pressure cap according to at least one of the previous claims, characterized in that the annular throttle gap ( 47 ,  147 ) of the first flow connection ( 50 ,  150 ) is so narrow that when pressure is applied through a liquid medium, a dynamic pressure occurs and overcomes the force of the second pressure spring ( 46 ,  146 ).  
     
     
         6 . Pressure cap according to one of the previous claims, characterized in that between the first valve body ( 17 ,  117 ) and the second valve body ( 18 ,  118 ), a cylindrical chamber ( 34 ,  134 ) is provided which is in communication with the throttle gap ( 47 ,  147 ) between the second and third valve bodies ( 18 ,  19 ;  118 ,  119 ).  
     
     
         7 . Pressure cap according to one at least one of the previous claims, characterized in that the first sealing seat ( 24 ,  124 ) on the second valve body ( 18 ,  118 ) lies radially outside the second sealing seat ( 32 ,  132 ) on the interior cap component ( 14 ,  114 ).  
     
     
         8 . Pressure cap according to at least one of the previous claims, characterized in that the second sealing seat ( 32 ,  132 ) on the interior cap component ( 14 ,  114 ) lies radially outside the third sealing seat ( 43 ,  143 ) on the third valve body ( 19 ,  119 ).  
     
     
         9 . Pressure cap according to at least one of the previous claims, characterized in that the sealing surfaces ( 21 ,  31 ,  39 ;  121 ,  131 ,  139 ) assigned to the respective sealing seats ( 24 ,  32 ,  43 ;  124 ,  132 ,  143 ) on the first valve body ( 17 ,  117 ), the second valve body ( 18 ,  118 ) or the third valve body ( 19 ,  119 ) point axially inward.  
     
     
         10 . Pressure cap according to at least one of the previous claims, characterized in that the first valve body ( 17 ,  117 ) is provided with a central opening ( 56 ,  156 ) through which a vacuum valve body ( 57 ,  157 ) extends whose sealing seat ( 61 ,  161 ) surrounds the central opening and is contiguous to the sealing surface ( 21 ,  121 ) of the first valve body ( 17 ,  117 ).  
     
     
         11 . Pressure cap according to  claim 10 , characterized in that the vacuum valve body ( 57 ,  157 ) is biased against the sealing surface ( 21 ,  121 ) of the first valve body ( 17 ,  117 ) with the aid of a spring ( 59 ,  159 ) supported by the top surface of the first valve body ( 17 ,  117 ).  
     
     
         12 . Pressure cap according to at least one of the previous claims, characterized in that an exterior cap component ( 113 ) from which the interior component ( 114 ) is suspended, is formed by the handling lids or closure elements ( 112 ,  110 ) which are connected via an axially movable coupling insert ( 180 ) which makes the said elements releasable and anti-rotational and whose axial movement is derived from the pressure-controlled axial movement of the first valve body ( 117 ).  
     
     
         13 . Pressure cap according to  claim 12 , characterized in that the axially movable coupling insert ( 180 ) is arranged axially above the first valve body ( 117 ) within the handling lid ( 112 ) of the exterior cap component ( 113 ).  
     
     
         14 . Pressure cap according to  claim 13 , characterized in that the a coupling insert ( 180 ) inside the handling lid ( 112 ) is biased by a pressure spring ( 181 ) in the direction of the closure element ( 110 ).  
     
     
         15 . Pressure cap according to at least one of  claims 12  to  14 , characterized in that the coupling insert ( 180 ) is constantly in anti-rotational communication with the handling lid ( 112 ) and is axially movable for engaging in and disengaging from the closure element ( 110 ).  
     
     
         16 . Pressure cap according to  claim 15 , characterized in that the coupling insert ( 180 ) is provided with a disk ( 185 ), from whose two surfaces claw elements ( 182 ,  183 ) extend which act jointly with axial recesses ( 173 ) in the handling lid or closure element ( 110 ,  112 ).  
     
     
         17 . Pressure cap according to at least one of  claims 12  to  16 , characterized in that a guidance element ( 171 ) for transferring the axial movement is provided between the coupling insert ( 180 ) and the first valve body ( 117 ).  
     
     
         18 . Pressure cap according to at least one of the previous claims, characterized in that the first valve body ( 117 ) is divided in two in radial connection and is provided with a radially interior valve body part ( 165 ) and a radially exterior valve body part ( 166 ) which are axially movable in relation to each other and are in communication with each other via an annular membrane seal ( 121 ).  
     
     
         19 . Pressure cap according to  claim 18 , characterized in that the guidance element ( 171 ) sits on the radially interior valve body part ( 165 ) of the first valve body ( 117 ), and that the radially exterior valve body part ( 166 ) of the first valve body ( 117 ) is biased by the pressure spring ( 122 ) for the first valve body ( 117 ).  
     
     
         20 . Pressure cap according to  claim 18  to  19 , characterized in that the sealing surface of the radially exterior valve body part ( 166 ) of the first valve body ( 117 ) bears on the sealing seat of the second valve body ( 118 ).  
     
     
         21 . Pressure cap according to at least one of  claims 18  to  20 , characterized in that the radially interior valve body part ( 165 ) of the first valve body ( 117 ) accommodates the vacuum valve body ( 157 ).