FR2684969A1 - Container containing a fluid product to be dispensed and a compressed gas, provided with a safety device with a mobile obturating body - Google Patents

Abstract

The invention relates to a pressurised container containing a fluid product to be dispensed and a compressed propellent gas which is not liquefiable at the pressure inside the container. This container comprises a stopper (6) made of deformable material, in which are formed two chambers (11, 12) connected with each other by a narrow passage (13), the first chamber (11) opening to the inside of the container and containing, for an internal pressure below a threshold, a mobile obturating device (14) and the second chamber (12) opening to the outside, the respective dimensions of the mobile device (14) and of the narrow passage (13) being such that the mobile device (14) can close the said narrow passage (13 ) under the effect of pressure and can move from the first chamber (11) to the second chamber (12) by deformation of the walls when the said pressure exceeds the said threshold.

Description

CONTAINER CONTAINING A FLUID PRODUCT FOR DISTRIBUTION
AND A COMPRESSED GAS PROVIDED WITH A DEVICE
SECURITY WITH MOBILE SHUTTER BODY.

 The present invention relates to a pressure container containing a fluid product to be dispensed and a propellant compressed gas, which cannot be liquefied under the pressure conditions inside the container, said container being provided with a safety device avoiding the risks of overpressure.

 Containers for dispensing a liquid under pressure, for example in the form of an aerosol, have been known for a long time. These containers are generally made up of a container with a bottom and side walls. On the edge of the side walls opposite the bottom is most often crimped a valve cup on which a dispensing valve is itself fixed. The valve is generally actuated by a device for driving the movable part of the valve. The container contains the product to be dispensed and the propellant, the latter being in direct contact with the product to be dispensed or contained in a separate pocket or capsule.

 Until recently, the propellant gas consisted of chlorofluorinated hydrocarbons, which had the advantage of being liquid at the pressures and temperatures used. However, following discussions concerning the destruction of the ozone layer by chlorofluorinated hydrocarbons, the industry is today led to develop alternative propellant systems. One of the solutions proposed consists in using compressed gases and, in particular, compressed air. However, these compressed gases, not being liquid at the pressures and temperatures used, can only constitute a reduced propellant reservoir inside an aerosol can, this reserve being able to be all the greater as the pressure is higher, however, especially for safety reasons, the pressure inside an aerosol canister should never exceed 12 x 105 pascals. Consequently, the manufacturer, on the one hand, is required to carry out pressurization under conditions close to the limit conditions and, on the other hand, must guarantee that the pressure does not exceed the authorized limit pressures, whatever storage conditions. However, when the gas is in direct contact with the product in the container, accidental variations in the filling rate with liquid or gas can cause overpressures during filling. It is therefore necessary to be able to detect and eliminate at the end of the filling chain the containers under too high pressure. Variations in temperature or pressure during storage or different manipulations can also cause overpressures which can go as far as explosion of the container, which is dangerous for the environment. When the compressed gas is contained in a separate capsule fitted with a differential pressure valve, this capsule may exhibit failures such as leakage or bursting, and under these conditions the pressure inside the container would increase dangerously for the 'user.

 Attempts have therefore been made to provide receptacles with this type of safety device making it possible to prevent the maximum allowable pressure from being accidentally exceeded.

 It is known from FR-A 1 463 533 to provide an orifice in the wall of the container and to cover it with a fragile membrane which ruptures under pressure. However, such a device can be accidentally torn during handling.

 This problem has been solved according to the invention by using a safety device consisting of a plug placed in the wall of the container, plug in which are formed two chambers communicating with each other by a narrowed passage, the passage between the two chambers being closed by a movable shutter member as long as the pressure remains below a predetermined threshold.

 The present invention relates to a pressurized container containing a fluid product to be dispensed and a propellant compressed gas which cannot be liquefied at the internal pressure of the container, at least one member of said container making it possible, on the one hand, to provide a distribution and on the other hand, a safety function preventing the pressure inside the container from exceeding a predetermined threshold, characterized in that said member comprises, to ensure at least the safety function, a plug of deformable material, in which are arranged two chambers communicating with each other by a narrowed passage, the first chamber opening towards the interior of the container and containing, for an internal pressure below said threshold, a movable obturation member, and the second chamber opening towards exterior, the respective dimensions of the movable shutter member and of said narrowed passage being such that the movable shutter member pui sse close said narrowed passage tightly under the action of the internal pressure of the container, as long as said pressure remains below said threshold and can pass from the first to the second chamber by deformation of the walls of the narrowed passage when said internal pressure exceeds said threshold.

 The movable closure member may have an ellipsoidal shape or more generally a shape of revolution, at least one of the end faces of which is shaped like a cone or a spherical or ellipsoidal cap. The movable member is however preferably made up of a spherical ball.

 During assembly, the ball is held in the first chamber either by the walls of the first chamber, or by tabs arranged on the edge of the opening of the chamber in the container.

In both cases, when the stopper is placed on the container, the pressure prevailing in this container (in the absence of overpressure) is sufficient to ensure the tight closure of the narrowed passage by the movable closure member.

 When the pressure in the container increases, the movable closure member exerts an increasingly strong thrust on the walls of the narrowed passage which deform until the ball passes into the second chamber. A stream of compressed gas then passes from the container into the first chamber, then into the second chamber and, from there, into the atmosphere, until the container is brought back to atmospheric pressure.

 The plug according to the invention is made of deformable material, preferably elastomeric: it is, for example, of natural or synthetic rubber.

 Under these conditions it can hardly be torn from the orifice of the wall of the container, in which it is placed, and the movable closure member, which is protected by the plug, is not likely to put the container in communication with the atmosphere during impacts on the wall of the container. Security therefore does not risk playing as long as the internal pressure remains below the predetermined threshold.

 The narrowed passage between the two chambers is preferably a cylindrical passage of circular section, the periphery of which can be defined by a flange.

 According to a first embodiment, the distribution and safety functions are provided, on the container according to the invention, by two separate members, the first being a dispensing valve and the second being a plug with a movable closure member such as above defined. In this case, when the container has a valve cup on which the dispensing valve is crimped, the cap is preferably placed in an orifice located on the valve cup, outside the crimping area of the valve.

 According to a second embodiment, the first chamber is connected by a dip tube to the phase of product to be dispensed contained in the container, an outlet tube being placed across the second chamber, said tube being supported by a of its ends on the movable obturation member and comprising at least one internal opening situated in the vicinity of its point of support on the movable obturation member, said tube opening at its other end towards the atmosphere, outside the second chamber, the communication opening between the first chamber and the container being defined by a deformable wall and having dimensions such that the movable shutter member can seal said communication.

 Preferably, the first chamber and the movable closure member have respective dimensions such that the movable closure member can simultaneously ensure, in the container, the sealed closure of the narrowed passage and of the communication between the first chamber and inside the container.

 Preferably also, the outlet tube carries a stroke limiter, located in the vicinity of its end which bears on the movable closure member. In fact, when the outlet tube closes off the communication between the second chamber and the atmosphere in a sealed or almost sealed manner, the propellant gas, in the event of overpressure, escapes entirely by passing through the outlet tube, and the inlet gas in this tube risks being blocked by the walls of the communication opening between the second chamber and the atmosphere; in addition, under the action of the overpressure, the outlet tube may be ejected outside the container if nothing retains it in position.

 The device of this second embodiment operates as follows. To actuate the valve, the user presses on the outlet tube which, in turn, presses on the movable closure member.

The latter moves towards the container thanks to the elasticity of the deformable wall formed between the first chamber and the container until the interior opening of the outlet tube is at the level of the first chamber. Under the pressure of the propellant compressed gas contained in the container, the liquid contained in the container passes through the dip tube, then into the first chamber and, from there, into the outlet tube which ejects it outside, which provides the distribution function.

 When the pressure of the compressed gas in the container increases beyond the predetermined threshold, the closure member passes from the first chamber into the second chamber by forcing the narrowed passage and pushing the outlet tube. The gas phase contained in the container is placed in communication with the atmosphere through the first chamber, the narrowed passage, the second chamber and the outlet tube, which ensures the safety function.

 The description of two embodiments, referring to the attached drawing and given below by way of illustration and in no way limitative, will allow a better understanding of the invention.

On this drawing:
- Figure 1 illustrates a first embodiment of the container according to the invention, in which the cap ensuring the safety function is independent of the valve ensuring the dispensing function
- Figure 2 is a view, in more detailed longitudinal section, of the cap used for the container of Figure 1;
- Figure 3 shows schematically another embodiment in which the plug provides both the safety function and that of distribution;
- Figure 4 schematically shows the cap of Figure 3 operating as a dispensing valve;
- Figure 5 shows schematically the cap of Figure 3 operating as a safety device.

 In the embodiment shown in Figures 1 and 2, we see that the container 1 is constituted by a metal can 2 having a bottom (not shown) and side walls. On the upper edge of the container 2 is fixed by crimping, a circular valve cup 3. A valve 4 is crimped, in a conventional manner, at the center of the cup 3 and is supplied, in the liquid phase to be dispensed by a dip tube 4a. An orifice 5 is formed in the bottom of the cup 3 outside the crimping zone of the valve 4; a plug 6 is placed in this orifice.

 The container 1 contains a liquid phase, to be dispensed in the form of an aerosol, and in direct contact with the liquid phase of the compressed air. The pressure inside the container is approximately 7 x pascals.

 The plug 6 is of generally frustoconical shape. This shape facilitates the introduction of the stopper 6 into the orifice 5. It is arranged in the orifice 5 so that the circular face of larger diameter 7 of the stopper is outside of the container 1, and the circular face of smaller diameter 8 or inside the container 1. On the frustoconical side wall of the plug 6, a groove 10 is formed in the vicinity of the face 7, this groove 10 allowing the snap fastening of the plug 6, on the edge orifice 5.

 In the plug 6 are formed two chambers il, 12 of revolution about the axis of the plug, these two chambers communicating with each other by a narrowed passage 13. The first chamber it contains, in operation at a pressure below the predetermined threshold not to not exceed, a movable shutter member, which is a ball 14. Said chamber 11 has a cylindroconical shape, the tip of the conical part being directed towards the narrowed passage 13. The diameter of the chamber 11 is such that the ball 14 can be easily inserted through the opening 8â opening in the face 8. In the absence of pressure, for example during the mounting of the cap, the ball 14 is held in place by flexible tabs 8b arranged around the opening 8a of the face 8. The chamber 12 has a cylindrical shape. The passage 13 between the chambers 11 and 12 is defined by an annular flange 15 of which, one face, chamber side 12, is perpendicular to the axis and the other face, chamber side 11, is inclined relative to this axis; the passage 13 therefore forms a cylinder of low height and of circular cross section. The chamber 12 has dimensions such that the ball can move there freely. The chamber 12 communicates with the outside via channels 16 opening to the outside through orifices 16a formed in the face 7 of the plug.

 The security device described above operates in the following manner. In the absence of overpressure, the ball 14 closes the passage 13 in a sealed manner thanks to the pressure prevailing in the container 1. When the pressure increases in the container, the ball undergoes in the chamber 1 1 an increasingly strong thrust until it causes the deformation of the flange 15 and passes through the passage 13 in the chamber 12. The gas phase of the container 1 then communicates via the chamber 11, the passage 13, the chamber 12 and channels 16, with the atmosphere. As long as the container is not at atmospheric pressure, the ball, under the pressure exerted by the compressed gas, remains in a position close to that shown in dotted lines in FIG. 2. When the container is at atmospheric pressure the ball falls back on the flange 15.

 FIG. 3 represents, in the normal storage position, a plug 106 ensuring both a safety function and a distribution function. The plug 106 is crimped substantially in the center of a valve cup 103, itself crimped on a container (not shown) similar to the container 2. The plug 106 has a generally cylindrical shape, an annular crown of larger diameter allowing the crimping. In the plug 106 are formed two chambers 111, 112 of revolution, communicating with each other by a passage 113; and the chamber 111 communicates by a bore 117 with the interior of the container. Due to the elasticity of the material constituting the stopper, the bottom of the chamber 111, in which the bore 117 is formed, constitutes a deformable wall. A ball 114 is placed in the chamber 111 as long as the pressure in the container remains below the predetermined threshold. The chamber 111 is cylindroconical and has a length, along the axis, such that the ball 114 can close in leaktight fashion, by elastic deformation, both the passage 113 and the bore 117. A radial pipe opening in the chamber 111 is connected to a tube 121 which plunges into the liquid product to be dispensed contained in the container. Chamber 112 has a cylindrical shape. The passage 113 between the chambers 111 and 112 is defined by a flange 115, one flat face perpendicular to the axis of the plug limits the chamber t12 and the other face, inclined relative to this axis, limits the chamber 111; passage 113 is therefore a cylinder of low height and of circular cross section. Chamber 112 communicates with a channel 116 with the outside. An outlet tube 118 is slidably mounted in an almost leaktight manner in the channel 116; it crosses the chamber 112 and the passage 113 and comes to bear against the ball 114; it is open at its outer end. The outlet tube 118 is closed at its end resting on the ball 114, but it has, at this level, a lateral opening, which, in the normal storage position, is disposed at the level of the annular flange 115. The tube outlet 118 carries a frustoconical projection 122, which limits the travel of said tube in chamber 112.

This projection 122 is arranged in the vicinity of the end of the tube 118 pressing on the ball 114; in the normal storage position, the projection 122 is in the vicinity of the flange 115. The small base of the truncated cone that constitutes the projection 122 around the outlet tube 118, is disposed on the side of the chamber 111. At the time of placing in place of the tube 118 in the stopper 106, the projection 122 is introduced into the chamber 112 by passage by force, the elasticity of the material constituting the stopper 106 nevertheless nevertheless ensuring a quasi-tightness around the tube 118. On the end external of the tube 118 is fixed by fitting a push button 119 provided with a spraying base 120.

 The stopper described above operates as follows: in the storage position at normal internal pressure, the chamber 111 is filled with liquid product to be dispensed because the communication between the chamber 111 and the compressed gas phase of the container is closed by the ball . When the user wishes to dispense the fluid, he presses the push button 119, so as to push the outlet tube 118 (see FIG. 4). The tube 118 pushes on the ball 114, which deforms the deformable wall at the level of the bore 117.

The seal of the ball 114 at the passage 113 is broken and, simultaneously, the liquid product can penetrate into the outlet tube 118 through its lateral opening which emerges from the flange 115: the liquid product is dispensed. When the user stops pressing, the plug 106 resumes its shape at the bore 117 and pushes the ball 114, which comes to seal the passage 113: the dispensing is interrupted. When the pressure inside the container increases, a thrust is exerted on the ball 114 by the gas phase of the container at the bore 117. The ball 114 pushes and deforms the flange 115. When the pressure exceeds a predetermined threshold , the ball 114 passes into the chamber 112, pushing the outlet tube 118 until the projection 122 comes into contact with the upper wall of the chamber 112 (see FIG. 5). The container is then in communication with the atmosphere; a flow of compressed gas passes from the container to the chamber 111, then to the chamber 112, then towards the outside, through the outlet tube 118.

Claims (10)

 1 - Pressurized container (1) containing a fluid product to be dispensed and a compressed propellant gas which is not liquefiable at the internal pressure of the container, at least one member of said container making it possible, on the one hand, to provide a distribution function and, d on the other hand, a safety function preventing the pressure inside the container from exceeding a predetermined threshold, characterized in that said member comprises, to ensure at least the safety function, a plug (6) made of deformable material, in which are formed two chambers (11, 111, 12, 112) communicating with one another by a narrowed passage (13, 113), the first chamber (11, 111) opening towards the interior of the container (1) and containing , for an internal pressure below said threshold, a movable closure member (14, 114) and the second chamber (12, 112) opening outward, the respective dimensions of the movable closure member (14 , 114) and said narrowed passage (13 , 113) being such that the mobile shutter member (14, 114) can close said narrowed passage (13, 113) in a sealed manner under the action of the internal pressure of the container as long as said pressure remains below said threshold, and can pass from the first (11, 111) to the second (12, 112) chamber by deformation of the walls of the narrowed passage (13, 113) when said internal pressure exceeds said threshold.  2 - Container according to 1, characterized in that one movable shutter member is a ball (14, 114).  3 - Container according to one of claims 1 or 2, characterized in that the plug (6, 106) is made of elastomer.  4 - Container according to one of claims 1 to 3, characterized in that the narrowed passage (13, 113) between the two chambers is a cylindrical passage of circular section defined peripherally by a flange (15, 115).  5 - Container according to one of claims 1 to 4, characterized in that the distribution and safety functions are provided by two separate members, the first being a distribution valve (4) and the second being a plug (6 ) with movable shutter member (14).  6 - container according to claim 5, characterized in that the container comprises a valve cup (3) on which is crimped the dispensing valve (4) and the plug (6) is placed in an orifice (5) located on the valve cup (3), outside the crimping area of the valve (4).  7 - container according to one of claims 1 to 4, characterized in that the first chamber (111) is connected by a dip tube (121) to the phase of product to be dispensed contained in the container, an outlet tube ( 118) being placed across the second chamber (112), said tube (118) bearing at one of its ends on the movable shutter member (114) and comprising at least one internal opening situated at the near its fulcrum on the movable closure member (114), said tube opening at its other end towards the atmosphere, outside the second chamber (112), the communication opening (117) between the first chamber and the container being defined by a deformable wall and having dimensions such that the movable closure member (114) can seal the said communication.  8 - A container according to claim 7, characterized in that the first chamber (111) and the movable closure member (114) have respective dimensions such that the movable closure member (114) can simultaneously ensure the closing the narrowed passage (113) and the communication between the first chamber (111) and the interior of the container.  9 - Container according to one of claims 7 or 8, characterized in that the outlet tube (118) carries a stroke limiter (122).  10 - A container according to claim 9, characterized in that the stroke limiter is a frustoconical projection (122) disposed around the outlet tube (118) in the vicinity of its end which bears on the movable closure member ( 114).