Abstract:
A sealing lid for the fixed nozzle of a container, particularly a motor vehicle radiator, comprising an outer part and an inner part. The outer part of the lid is provided with a sealing element for the container nozzle and a grip element which is rotatable in relation thereto. A torsional stop acts between the grip element and the sealing element of the outer part of the lid. The inner part of the lid is provided with a flow connection between the inside and outside of the container and a valve system opening and closing the flow connection. The torsional stop which can be disengaged by applying prestress to a spring or is disengaged, can be engaged by a pressure-controlled drive in the form of a membrane. The drive is positioned in the outer part of the lid and is provided with an elongate pressure-transmitting element which penetrates the pressure relief valve body in the lid axis and extends into the area of the inner part of the lid, which is connected to the container nozzle so as to interact therewith. The suction relief valve body is arranged concentrically to the lid axis.

Description:
FIELD OF THE INVENTION 
   The invention related to a closure cap for a fixed neck of a container, in particular a motor vehicle radiator, having an outer cap element and an inner cap element. The outer cap element has a closure element for the container neck and a grip element which can be rotated relative to the closure element. A twist-prevention device is provided which acts between the closure element and the grip element, and a valve arrangement is provided serving to release or block a flow connection defined by the cap element between the interior of the container and the exterior of the container. The valve arrangement has an axially movable overpressure valve body which is pressed under initial tension toward the interior of the container against a seal at the inner can element in such a way that, when a threshold value of the interior container pressure is exceeded, it can be lifted off the seal, and the underpressure valve body. 
   BACKGROUND OF THE INVENTION 
   In such a closure cap known from DE 197 53 597 A1, the twist-prevention device between the closure element and the grip element is constituted by an axial coupling bolt, which is acted upon by a spring arrangement which operates as a function of temperature. 
   In connection with a further closure cap known from DE 199 23 775 A1, the twist-prevention device is constituted by a strap, which is axially movable and is arranged inside the grip element and can be operated by a thermal drive in the form of an expandable material. In both these known cases it is difficult to transmit the actual heat in the container to the twist-prevention device, which can be affected by heat, without considerable temperature losses. This is difficult to obtain, not least because of the valve arrangement in the form of an overpressure or underpressure valve arranged in the path between the container interior and the twist-prevention device. This correspondingly also applies to those closure caps which, as already suggested, operate by means of a pressure-controlled twist-prevention device. 
   SUMMARY OF THE INVENTION 
   It is the object of the present invention to provide a closure cap for a fixed neck of a container, in particular a motor vehicle radiator, of the type mentioned at the outset, to whose twist-prevention device, or its drive mechanism, it is possible to transmit the temperature in the container interior, or the pressure in the container interior, to the twist-prevention device, or its drive mechanism, in a simpler manner and without impermissibly high losses. 
   The twist-preventing element is disengaged by means of a thermally or pressure-controlled drive mechanism in the form of a capsule made of an expandable material, or of a diaphragm. The drive mechanism is arranged in the outer cap element and is provided with a linearly extending transmitting element which penetrates the overpressure valve body in the cap axis and extends into the area of the inner cap element which is connected with the neck of the container and that the underpressure valve body is arranged concentrically with respect to the cap afix. This arrangement is provided to attain this object in connection with a fixed neck of a container, in particular a motor vehicle radiator, of the type mentioned. 
   By means of the steps in accordance with the invention it has been achieved that the drive element in the form of a capsule made of an expandable material, or a diaphragm, and operating as a function of temperature or a function of pressure, can pick up the temperature prevailing in the container interior, or the pressure prevailing in the container interior, without losses and without delay. The transmission of the temperature and pressure conditions in the container interior can be done in the shortest and most direct way directly in the course of the cap access, without having to tolerate disadvantages in the action of the overpressure valve body and especially in the action of the underpressure valve body. Because of the concentric disposition of the underpressure valve body, a short construction of the inner cap element is also achieved. 
   In a first preferred exemplary embodiment of the present invention in accordance with which the underpressure valve body is integrated with the twist-prevention device. The space inside the cap, that is, between the grip element and closure element, is advantageously used for the underpressure valve body. This does not cause any increase in structural height. 
   Advantageous features in this respect are defined by the fact that the twist-prevention device is formed by a blocking plate, in the middle region of which, oriented forward the pressure-controlled or thermally-controlled drive mechanism, the underpressure valve body is retained in axially spring-loaded fashion; and/or the underpressure valve body is retained axially movable in a central bore in the blocking plates, and a compression spring acting between the underpressure valve body and the top of the blocking plate presses an annular sealing face of the underpressure valve body against the underside of the blocking plate. 
   In a second preferred exemplary embodiment of the present invention the underpressure valve body surrounds the elongated pressure- or temperature-transmitting element, preferably near the free end of the inner cap element. The underpressure valve body is disposed in the course of the pressure- or temperature-transmitting element. Once again, this does not increase the structural height. 
   In a preferred way, the underpressure valve body is integrated with the overpressure valve body. This results in a simplified structural embodiment and simplified installation of the underpressure valve body together with the overpressure valve. 
   While this last embodiment of the underpressure valve body integrated with the overpressure valve can advantageously be used and is possible with both pressure- and temperature-controlled driving of the twist-prevention device, the installation and use of the underpressure valve body disposed between the grip element and closure element is especially advantageous in the pressure-controlled embodiment of the twist-prevention device. 
   An advantageous feature of the pressure- or temperature-transmitting element is obtained by embodying it as a hollow or solid rod, along whose outer circumference the overpressure valve body, prestressed by an axial compression spring, is guided. 
   Preferred and advantageous features in terms of the integration of the underpressure valve body and overpressure valve body are characterized in that between an annular sealing sent for the overpressure valve body, on a centrally pierced bottom of the inner cap element, and the underside, remote from the axial compression spring, of the overpressure valve body, the liftable outer circumferential require of a sealing diaphragm is disposed, whose inner circumferential region brinas about an overpressure sealing that is constantly axially operative for the overpressure valve body between the overpressure valve body and the elongated pressure- or temperature-transmitting element, and characterized in that the inner circumferential region of the sealing diaphragm can be lifted away counter to the action of a compression spring that acts in the direction of an overpressure, and characterized in that the inner circumferential region of the sealing diaphragm is pressed against a shoulder of the elongated pressure- or temperature-transmitting element, and the compressing spring is braced on the bottom of the inner cap element. 
   Further features of the pressure-transmitting element, its diaphragm, and the twist-prevention device are characterized in that the pressure-transmitting element has a through bore, whose inlet side, toward the container, discharges at the bottom of the inner cap element, and whose outside, remote from the container, is covered by the diaphragm in that the diaphragm, with its central region, is opposite the outlet side of the through bore. is fastened in Diace in pressure-proof fashion on the outer circumference, and on the inner circumference rests between the underside of the blocking plate and the annular sealing face of the underpressure valve body, and in that the diaphragm is fastened in place on the circumferential region of all end flange of the pressure-transmitting element, and in that the inner cap element has a centrally pierced false bottom, on the top of which the flange, provided with the diaphragm, or the capsule made of expandable material rests, and from whose underside the valve arrangement is suspended, and in that the blocking plate is connected nonrotatably but axially movably to the closure element, and that radially outward-point prongs of the blocking plate become engaged between readially inward-pointing prongs of the grip element. 
   Further details of the invention can be found in the description which follows, in which the invention is described in greater detail and explained by means of exemplary embodiments shown in the drawings. Shown are in: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1 , a schematic representation in longitudinal section of a closure cap for a motor vehicle radiator with a pressure controlled twist-prevention device in accordance with a first exemplary embodiment of the present invention, the right and left half-sections respectively representing one of the two end positions, and 
       FIG. 2 , a representation corresponding to  FIG. 1 , but with a closure cap with a temperature controlled twist-prevention device in accordance with a second exemplary embodiment of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The closure cap  10  or  110 , shown in the drawings in two exemplary embodiments, has an overpressure/underpressure valve arrangement  11  or  111 , which has an overpressure valve body  12  or  112  and an underpressure valve body  13  or  113 , which in the exemplary embodiment of  FIG. 1  are formed by components disposed at different places and in the exemplary embodiment of  FIG. 2  are formed by components connected to one another or integrated with one another. The opening pressure of the overpressure valve body  12 ,  112  is fixedly set by means of a helical compression spring  44 ,  144 , and the opening pressure of the underpressure valve body  13 ,  113  is likewise fixedly set by means of a helical compression spring  66 ,  166 . 
   In accordance with the representation in the drawings, the outer lid  16  or  116 , which is identical in both exemplary embodiments, of the closure cap  10  or  110  has a closure element  17 ,  117 , which is here in the form of an exterior thread element for screwing the closure cap onto or off the opening of a neck, not shown here, of a motor vehicle radiator or other container, and a grip element  18 ,  118 , which is rotatable in relation to the closure element  17 ,  117  and can be connected with it, fixed against relative rotation, by means of a twist-prevention device  19 ,  119 , which is identical in both exemplary embodiments. A drive mechanism  14 ,  114  for disconnecting the twist-prevention device  19 ,  119  is arranged, the same as the latter itself, in a space between the grip element and the closure element  18  and  17 , or  118  and  117 . It is understood that the closure element  17 ,  117  can also be embodied as a quarter-turn fastener instead of as an exterior thread element. 
   The closure element  17 ,  117  has an intermediate bottom  21 ,  121  provided with an axial opening, from whose underside a sleeve  23 ,  123  with an exterior thread, and from whose top a connecting sleeve  24 ,  124  project axially, by means of whose radial flange  22 ,  122  the closure element  17 ,  117  is rotatably maintained at the grip element  18 ,  118 , but is kept suspended axially immovable. The grip element  18 ,  118  extends underneath the outer edge of the flange  22 ,  122  of the connecting sleeve  24 ,  124  of the closure element  17 ,  117  and has in its center a guide ring  25 ,  125 , which projects axially inward and within which a compression spring  26 ,  126  is received, whose one end is supported on the inside of the grip element  18 ,  118 , and its other end on a blocking plate  27 ,  127  of the twist-preventing element  19 ,  119 . The blocking plate  27 ,  127 , in both axial positions, is connected to the closure element in a manner fixed against relative rotation, specifically by means of outer, axially downward-protruding claws  29 ,  129 , which mesh constantly with axial grooves  31 ,  131  in the closure element  17 ,  117 . The blocking plate  27 ,  127  furthermore has radially protruding prongs  28 ,  128  on the outer circumference, which in one end position (right half-section) become engaged between retaining prongs  30 ,  130  that protrude radially inward from the grip element  18 ,  118 . In this position, the twist-prevention device  19 ,  119  is connected in a manner fixed against relative rotation not only to the closure element  17 ,  117  but also to the grip element  18 ,  118 , which allows the closure cap to be screwed onto or off the container neck, not shown. As will still be shown, the twist-preventing element  19 ,  119  can be axially moved against the action of the compression spring  26 ,  126  in such away that the prongs  28 ,  128  are released from the interstices between the retaining prongs  30 ,  130  (left half-section), so that the rotating connection between the twist-prevention element  19 ,  119  and the grip element  18 ,  118  is released, which results in a free-wheeling rotation of the grip element  18 ,  118  on the closure element  17 ,  117  and prevents the unscrewing of the closure cap  10 ,  110  from the container neck. 
   An inner cap element  15 ,  115 , which holds the overpressure valve body  12 ,  112  of the valve arrangement  11 ,  111 , is suspended from the closure element  17 ,  117  of the outer cap element  16  or  116  in such a way that the inner cap element  15 ,  115  is axially immovable in respect to the outer cap element  16 ,  116 , but can be rotated in the circumferential direction. The inner cap element  15 ,  115  has a valve cup  36 ,  136 , which is suspended from the closure element  17 ,  117  and has radial flow-through openings, not shown. A bottom  38 ,  138  of the valve cup  36 ,  136  is provided with an inner opening  39 ,  139 , around which an annular sealing face  41 ,  141  is provided, which is axially raised toward the interior, the overpressure valve body  12 ,  112  rests with a radially outer sealing face  42 ,  142  of a sealing diaphragm  43 ,  143  on the annular sealing face  41 ,  141  by means of the action of the compression spring  44 ,  144 , which has a defined initial tension. The overpressure valve body  12 ,  112  is approximately hat-shaped, and the sealing diaphragm  43 ,  143  is received inside of its brim, which is axially bent inward on its periphery toward the bottom  38 ,  138 . The sealing diaphragm  43 ,  143 , whose outer circumferential region or radially outer sealing face  42 ,  142  rests on the annular sealing face  41 ,  141 , is retained in fixed fashion on its inner circumferential region or radially inner sealing face  58 ,  158 , in the exemplary embodiment of  FIG. 1 , but conversely in the exemplary embodiment of  FIG. 2  is retained in openable fashion by the action of a compression spring, as will be described hereinafter. The inner central blind-bore recess  39 ,  139  in the bottom  38 ,  138  communicates via connecting openings  48 ,  148  with the interior of the container, not shown, or its container neck. 
   The drive mechanism  14 ,  114  for the twist-preventing element  19 ,  119 , which is arranged between the blocking plate  27 ,  127  and the intermediate bottom  21 ,  121 , is provided with a linearly extending transmitting element  54 ,  154 , which extends along the closure cap axis  55 ,  155 , penetrates the overpressure valve body  12 ,  112 , including the sealing diaphragm  43 ,  143 , and is joined in or on the far side of a central continuous opening  49 ,  149  in the bottom with the container, not shown. The transmitting element  54 ,  154  is used for transmitting the pressure or temperature conditions in the container interior to the pressure-controlled or thermally-controlled drive mechanism  14 ,  114  of the twist-preventing element  19 ,  119 . The transmitting element  54 ,  154  is embodied in the manner of a hollow or solid rod, and the section facing the twist-preventing element  19 ,  119  has a larger diameter than the section, adjoining it and ending in the opening  49  in the bottom  38 ,  138 , underneath the overpressure valve body  12 ,  112 . The inner circumferential region or in other words the radially innermost sealing face  58 ,  158  of the sealing diaphragm  43 ,  143  of the overpressure valve body  12 ,  112  is sealingly maintained on the thus-formed annular shoulder  56 ,  156  of the transmitting element  54 ,  154 , at least when normal pressure or overpressure prevails in the container interior. In the upper section of larger diameter, the transmitting element  54 ,  154  is used for guiding a guide sleeve  46 ,  146 , which surrounds it, of the overpressure valve body  12 ,  112 . 
   In the exemplary embodiment of  FIG. 1 , and the drive mechanism is pressure-controlled, the transmitting element  54  is embodied as a hollow rod  54  with a through-bore, whose access opening is located in the plane of the bottom  38 . On the side facing away from the bottom  38 , the hollow rod  54  is provided with a flange  57 , which rests on the intermediate body  21  of the closure element  17 . On the side of the flange  57  facing the blocking plate  27 , a diaphragm  50  constituting the drive mechanism  14  is maintained, its outer circumferential side being clamped in a pressure-proof manner. In the unpressured initial position shown in the right half-section in  FIG. 1 , the diaphragm  50  which seals the container interior in a pressure-proof manner against the grip element  18  rests centrally on the flange  57  and covers the through-bore  56  of the hollow rod  54 . In an annular area between said center area  51  and its clamped area, the diaphragm  50  is provided with an annular bulge  52 , which makes possible the axial deflection of the center area  51  of the diaphragm  50 . The center area  51  of the diaphragm  50  is pressed against the flange  57  by the action of the compression spring on the blocking plate  27 . 
   In this exemplary embodiment, the flange  57  is retained in a manner fixed against relative rotation on the outer circumference by hooks that engage the false bottom  21  of the closure element  17 . 
   In the exemplary embodiment of  FIG. 2 , the drive mechanism  114  is constituted by a thermo-capsule  150 , which rests with its outer rim on the intermediate bottom  121  of the closure element  117 , and on which the center area of the blocking plate  127  rests centrally by the action of the compression spring  126 . The bottom of the thermo-capsule  150  makes a transition into an elongated, hollow thermal extension  154 ′, which is closed at the end and is disposed inside the hollow rod  154  and protrudes past the bottom  138  of the valve cap  136 . The thermo-capsule  150  and the extension  154 ′ contain an expandable material, which expands under the effect of heat in case of a temperature increase. The extension  154 ′ can also be embodied as a solid rod and can transmit the heat from the container interior to the thermo-capsule  150 . 
   The underpressure valve body  13 ,  113  is embodied differently in the two embodiments. It is understood that the underpressure valve body  13 ,  113  described for one exemplary embodiment can also be realized in the other exemplary embodiment. 
   The underpressure valve body  13  shown in  FIG. 1 , which is embodied as a separate component from the overpressure valve body  12 , is designed as integrated with the blocking plate  27  of the twist-prevention device  19 . The blocking plate  27 , like the diaphragm  50 , has a central opening  32 , which is penetrated by the underpressure valve body  13 . The underpressure valve body  13 , on its lower end, has a shoulder  67  with an annular sealing face  65 , which is pressed against the underside of the diaphragm  50  by the action of the compression spring  66 . The head  68 , protruding from the shoulder  67  provided with the annular sealing face  65 , of the underpressure valve body  13  protrudes outward past the top of the blocking plate  27  and is provided there with an undercut, in which the compression spring  66  is braced on one end, while on its other end the compression spring  66  rests on the top of the blocking plate  27 . The underpressure valve body  13  thus moves in the axial direction together with the blocking plate  27 . In the rotationally locked position of the blocking plate  27  shown in the right half-section of the section in  FIG. 1 , the underside of the shoulder  67  of the underpressure valve body  13  plunges into a region of the through bore, which bore is funnel-shaped here, of the pressure-transmitting element  54 . In this way, when negative pressure prevails in the container interior, the underpressure valve body  13  can lift with its annular sealing face  65  away from the diaphragm  50 , counter to the action of the compression spring  66 , so that a pressure equilibrium can be brought about. 
   The underpressure valve body  113  of  FIG. 2  is integrated with the overpressure valve body  112 , or its sealing diaphragm  143 . While in the exemplary embodiment of  FIG. 1 , the inner sealing face  58  of the sealing diaphragm  43 , resting on the annular shoulder  56 , is retained in fixed fashion by a ring  45  braced on the bottom  38  of the valve cup  36 , in the exemplary embodiment of  FIG. 2  the radially inner annular sealing face  158  is pressed by a compression spring  166  against the annular shoulder  156 . The compression spring  166 , which is braced on the bottom part  138 , is adjusted such that when negative pressure prevails in the container interior, the annular sealing face  158  of the underpressure valve body  113  lifts from the annular shoulder  156  counter to the action of the compression spring  166 , so that a pressure equilibrium can be brought about. 
   The coolant will be heated while the engine is operated, so that the temperature or the pressure rises in the container. In accordance with the left half-section of  FIG. 1 , the diaphragm  40  is deflected during a pressure increase by the transmitting element  54 ,  154 , which is connected with the drive mechanism  14 ,  114 , and is moved axially in the direction of the arrow B against the action of the compression spring  44 , while in the exemplary embodiment in accordance with  FIG. 2 , left half-section, the expandable material is expanded because of the temperature increase and the thermo-capsule  150  expands axially in the direction of the arrow B against the action of the compression spring  144 . In both cases is the blocking plate  27 ,  127  lifted in the direction of the arrow B, while compressing the compression spring  44 ,  144 , so that the prongs  28 ,  128  are released in the axial direction from between the retaining prongs  30 ,  130 . In this state, the connection, fixed against relative rotation, between the grip element  18 ,  118  and the closure element  17 ,  117  is released, so that the grip element freely rotates in respect to the closure element. This free-wheeling connection between the grip element  18 ,  118  and the closure element  17 ,  117  prevents the unscrewing of the closure cap  10 ,  110  from the container neck. If normal output values for the pressure or temperature again prevail in the container interior, the twist-preventing element  19 ,  119  comes again into its initial position by means of the action of the compression spring  44 ,  144 , so that the closure cap  10 ,  110  can again be unscrewed because of the connection, fixed against relative rotation, between the grip element  18 ,  118  and the closure element  17 ,  117 .