Pre-compression pump for diffusing a liquid

Abstract

Improvement to the provisions as defined in any one of the claims of the main patent. According to the addition, the pre-compression conduit 6 is joined to at least two separate compression chambers 5a, 5b, connected respectively to two separate liquid reservoirs 42a, 42b, each compression chamber having a closing valve 14a, 14b closing or opening a sampling orifice 13a, 13b of a liquid 45a, 45b from a reservoir and a driving piston 11a, 11b for transferring this liquid to the pre-compression conduit through an intermediate transfer chamber 8a, 8b, the liquids from the two reservoirs by effect of the simultaneous control of the two driving pistons mixing in the pre-compression conduit before exiting through the expulsion orifice 25 towards the diffusion head 26.

Description

First certificate of addition to the main application no. 88.10047 of July 26, 1988 Pre-compression pump for diffusing a liquid LIQUID The main patent relates to a pre-compression pump for the diffusion of a liquid, comprising an orifice for the intake of this liquid from a reservoir bottle, which can be closed by a shut-off valve, an orifice for the expulsion of the liquid to a diffusion head and a support shell in which is made a first internal compression chamber, a driving piston cooperating with the first chamber for the transfer of the liquid between the intake orifice and the expulsion orifice, characterized in that it further comprises a second intermediate transfer chamber between the first chamber and the expulsion orifice and a pre-compression conduit formed in the support shell in a cooperating position with pre-compression means mounted in this shell, the first chamber being parallel and not coaxial with the pre-compression conduit. Such a pump structure is more particularly intended to be mounted on a container or jerrycan for spraying a liquid product in aerosol form, making it possible to do without the use of a propulsion gas previously enclosed under pressure inside this container, in order to project the liquid through a nozzle or similar device mounted in the diffusion head, this thanks to means which perform a prior compression of the liquid doses to be delivered, taken from the reservoir bottle by the effect of the motor piston. It defines, in particular, a pre-compression pump arranged so that the diffusion head is fixed relative to the pump body and, specifically, independent of the movement of the piston that draws the liquid from the reservoir. This improves the conditions under which the liquid aerosol is projected, notably by allowing for more precise targeting of the area to be reached. Furthermore, it enables the diffusion of predetermined unit doses of constant volume, regardless of the pump's position, even when the pump body is inverted for use upside down, which is not possible when the pump body is designed to deliver a pressurized propellant aerosol. The advantages of the pre-compression pump thus arranged are obtained in particular thanks to the provision in the pump, between the first chamber where the compression of the liquid drawn from the reservoir bottle by the sampling orifice takes place, of an intermediate transfer chamber, arranged transversely in the casing through the support shell, so that the liquid dose drawn by the motor piston and brought into the compression chamber is pumped into a separate pre-compression unit, the pump thus ensuring a total separation of the functions of drawing and then pre-compression of the liquid before its expulsion by the nozzle of the diffusion head. This addition relates to improvements made to a pump of the type recalled above, as claimed with the main patent, making it possible in particular to carry out with the same assembly the in situ mixing of two or more liquid products, generally different, or of a liquid and a quantity of air suitable to produce an emulsion of the latter, again without having to use a pressurized gas for the propulsion of these products at the time of their common projection by the nozzle of the diffusion head. The envisaged improvements make it possible, in addition to the advantages inherent in the structure of the pump according to the main patent, to avoid the disadvantages of known systems where the mixing of the products is carried out by placing in an external container containing a first liquid, a second container or internal container containing the other liquid, each container being equipped with a valve, the valve of the internal container being joined to that of the external container by a shell delimiting an enclosed space where the mixing takes place before the emulsion of these two products exits through the valve of the external container, under the effect of a propellant gas enclosed in the two containers with the corresponding liquids. In particular, with this type of known system, the shell necessarily contains, after each spraying, a residual volume of the mixture of the two liquids which can freeze or solidify more or less completely, limiting, or even preventing, further spraying, and in any case modifying the texture of the mixture at the beginning of each new use. Furthermore, these conventional systems are necessarily designed to operate in continuous diffusion mode, as long as the user applies pressure to the valve releasing the mixture outlet under the effect of the propellant gas, and therefore cannot provide precise, limited doses. Finally, they are complex to manufacture and consequently represent a significant cost, independent of the cost of the liquid products themselves. According to this addition, the pre-compression pump considered is characterized in that the pre-compression conduit is joined to at least two separate compression chambers, connected respectively to two separate liquid reservoirs, each compression chamber having a closing valve that closes or opens an orifice for the withdrawal of a liquid from a reservoir and a driving piston for the transfer of this liquid to the pre-compression conduit through an intermediate transfer chamber, the liquids from the two reservoirs by effect of the simultaneous control of the two driving pistons mixing in the pre-compression conduit before exiting through the expulsion orifice to the diffusion head. Preferably, the pre-compression pump is associated with two reservoirs, each containing a different liquid to be mixed in the pre-compression chamber, where these liquids are introduced through independent inlets from the compression chambers, themselves connected respectively to each of the reservoirs. Of course, it goes without saying that the term "liquid" used here covers a wide range of products, regardless of their relative densities or fluidities; these products may be pasty, take the form of foam, or be in any other form suitable for each use. Thus, and in an alternative embodiment, one of the two reservoirs can be removed, the mixing of the liquid from the other reservoir being carried out with air pressurized in the first compression chamber. The provisions envisaged in accordance with this addition lead to the same advantages as those listed in the main patent, in particular by avoiding the use of any propellant gas, especially based on chlorofluorinated products or even more so containing a hydrocarbon whose use is already prohibited or is likely to be prohibited in the near future by current or future regulations, especially for widespread domestic applications, due to the risks to the environment and the dangers of flammability or explosion. The pre-compression pump also offers the ability to deliver precise doses of the mixture produced, the ratio corresponding to this mixture being able to vary on demand either according to the stroke of the engine pistons in the compression chambers or according to the respective diameter of these chambers. According to an advantageous feature of this addition, the liquid reservoirs are made up of deformable pouches, made in any shape or with any suitable material. These bags can be made of plastic, a composite material combining metal and plastic, or simply metal, like the deformable tubes used to hold toothpaste or other products of similar consistency. These bags are preferably screwed or snapped onto the end of the pre-compression chambers, directly above the chamber's dispensing ports, before being filled with liquids. This allows for the possibility of replacing the bags with new ones after they have been completely used, while retaining the pump itself. Alternatively, however, the bags can be welded or otherwise secured to the compression chambers. Filling the bags with the liquids to be mixed is easy, as the containers are placed upside down and have a removable base that has been previously detached. The bags are mounted on the compression chambers, with their opposite ends open to allow the liquids to be poured into them. Once filled, these ends are closed, either by crimping or other means; the flexibility of the bag material allows this operation without any particular difficulty. As liquid doses are drawn from the bags, they gradually deform, forcing the contents into the compression chambers until they are completely empty. Other features of a pre-compression pump equipped with the improvements according to this addition will become apparent from the following description of several exemplary embodiments, given by way of illustration and not limitation, with reference to the attached drawings in which: - Figure 1 is an axial cross-sectional view of a pre-compression pump as provided in the main patent, but adapted for the homogeneous mixing of two separate liquid products; - Figure 2 is a cross-sectional view along line II-II of Figure 1; - Figures 3 and 4 are detailed perspective views of components used in the embodiment of the pre-compression pump under consideration; - Figure 5 is a top view of the pump according to Figure 1; - Figure 6 is a partial side view of the upper end of the pump of Figure 1;- Figure 7 is a view of the lower end of the pump casing, containing the reservoirs for the two liquids1 the casing being shown upside down, prior to filling these reservoirs; - Figure 8 is an axial cross-sectional view of an alternative embodiment of Figure 1, more particularly adapted to the mixing of a liquid and air for the emulsification of this liquid. We have used on these figures the same reference numbers as those used in the main patent, to identify the same elements of the pump, also designated under the same terms. In Figure 1, reference 1 designates the bottle or external casing 1 equipped at its upper end in accordance with the invention, with a pre-compression pump whose operating principles are identical to those envisaged in the main patent, the pump being however equipped here with the improvements according to the present addition. The boot 1 includes internally a support shell 2, comprising in its central part a tubular extension 4 inside which is fitted a pre-compression conduit 6. This includes at its upper part an expulsion orifice 25, closed by a needle piston 23, normally applied against the orifice 25 under the effect of a spring 24. Channels 31 are provided on either side of the conduit 6 in a piece forming an end piece 22, mounted in the extension 4. A groove 34 connects the channels 31 with spaces 35a, 35b formed between vertical grooves in the part 22. A nozzle 27 is provided on the diffusion head 26, connected to the expulsion orifice 25. The upper part of the casing 1 is covered by a protective cap 30, which is advantageously snapped onto the casing and has a lateral opening 29, so as to allow space for a movable plunger 10. Preferably, this plunger has a slightly recessed central portion 40 and a hollowed central portion 41, allowing passage of the head 26 when the plunger is pressed (see also the Figure 6). In accordance with the provisions of this addition, the assembly envisaged is designed to ensure the collection, compression and mixing of two different liquid products, brought simultaneously into the pre-compression conduit, before expulsion by the nozzle of the diffusion head, thanks to the mounting of two separate sub-assemblies inside the same housing, separately carrying out the collection of these liquids and then their simultaneous transfer to the conduit and the head. In the drawing, the parts of the pump which allow the withdrawal and transfer of the two liquids are designated under the same references, each of them being assigned the indices a and k respectively depending on whether it is one or the other of these liquids and the parts which concern them. As can be seen in Figures 1 and 2 in particular, the shell 2 thus supports two compression chambers 5a, 5b, each of them comprising a driving piston 11a, 11b actuated simultaneously by the pusher 10 against a spring 28a, 28b. In each chamber 5a, 5b, opposite the piston, there is a sampling orifice 13a, 13b, normally closed by a ball 14a, 14b, forming a valve. Each compression chamber is also connected by a lateral passage 16a, 16b to a transfer chamber 8a, 8b, which communicates with the pre-compression conduit 6 via the groove 34 and the spaces 35a, 35b. The chambers 8a, 8b each have a ball valve 18a, 18b, and a spring 19a, 19b, designed to press the ball against the passage 16a, 16b, thus closing it. The sampling ports 13a and 13b are connected in parallel to two reservoirs 42a and 42b, housed side by side in the casing 1, Each reservoir has an end collar 43a, 43b, here screwed against an end piece 44a, 44b, provided in a retaining piece 7, fixed under the shell 2 (see Figure 3). Of course, each reservoir 42 could be mounted under the piece 7 at the openings 13 and the associated valve 14 by another means, removable or not, for example by snap-fitting, welding, or crimping. Each reservoir 42 contains a liquid product 45a, 45b respectively, and is normally closed at its lower end 46a, 46b, by crimping, knurling or other similar means. Figure 7 shows the housing 1 and the reservoirs 42a and 42b it contains, prior to their filling with the liquids 45a and 45b, the housing being shown upside down. Once filled, the ends 46a and 46b are folded and crimped to ensure a tight seal of these reservoirs. The housing can then be closed by fitting an end cover 47, which has a lateral collar 48 that is press-fitted into a counter collar 49 at the end of the housing. A vent 50 is usually provided in the center of the cover 47. Advantageously, the reservoirs 42a and 42b consist of pouches made of plastic material, metal-plastic composite, or metal, of the type of toothpaste tube or other, of substantially conical shape, allowing progressive crushing of the pouches as the liquids they contain are evacuated towards the compression chambers 5a and 5b, until these pouches are completely emptied and can then be replaced by others suitably filled according to the indicated process. The operation of the pre-compression pump thus produced can be easily deduced from the indications given above, by reference to the details provided in the main patent. With reservoirs 42a and 42b previously fixed to the ends of compression chambers 5a and 5b and filled with their respective liquids 45a and 45b according to the indicated process, the apparatus is ready for use. Each actuation of the movable piston 10, by drawing a dose of these liquids from each of the compression chambers, first causes the liquid already present in these chambers to be sent to the pre-compression conduit, in a manner precisely specified in the main patent. The two liquids received in the conduit 6 are thoroughly mixed as they pass through the expulsion orifice 25 and expelled together through the nozzle 27 of the head 26. With each stroke of the pistons 1la, 1lb, the chambers 5a, 5b take a new dose, exactly determined, at the same time as the pre-compression conduit 6 receives equivalent doses, closely mixed and delivered precisely and always identical to itself with each command of the pusher 10. Figure 8 illustrates another variant embodiment where one of the compression chambers, for example chamber 5a, is not associated with a flexible reservoir 42, but opens directly into the internal atmosphere of the bootmaker 1, which is brought to the open air by the vent 50 provided in the cover 47. In this variant, the liquid 45b taken from the bag 42b is compressed in the chamber 5b and forced into the pre-compression conduit 6. In this conduit, it is mixed with air from the chamber 5a, the emulsion thus produced being then delivered through the expulsion orifice 25 into the diffusion head 26. Preferably, this head includes a mixing screw 51, provided with a helical thread 52, this screw being rotatably mounted in a bore 5.3 of the head 26, to achieve the desired mixing of the liquid and air before exiting through the nozzle 27. Whatever variant is adopted, a pre-compression pump is thus produced that provides a homogeneous and constant mixture of two liquid or pasty products, possibly an emulsion of a liquid in the form of an intimately stirred aerated foam, but always without the addition of gas previously enclosed under pressure in the casing. This is usually made of aluminium or other light metal; however, depending on the case, due to the absence of pressurised propellant gas and as a result of dielectric couples with the liquids in the tanks possibly creating harmful corrosion points, it may be possible to consider making the boots out of different materials, in particular with suitable plastics. The device is simple, inexpensive, and very easy to use, with increased reusability through the simple replacement of the liquid bags without having to replace the pump itself. The delivered doses can be precisely determined with a ratio that depends only on the stroke of the motor piston or the diameter of the compression chambers, as defined by the design. Finally, the application of the device to all kinds of products according to the desired conditions of use is easy and does not require any adaptation that would modify the overall structure of the device.

Claims

DEMANDS 1. Improvement to the provisions as defined in any one of the claims of the main patent, characterized in that the pre-compression conduit (6) is joined to at least two separate compression chambers (5a, 5b), connected respectively to two separate liquid reservoirs (42a, 42b), each compression chamber having a closing valve (14a, 14b) closing or releasing a sampling orifice (13a, 13b) of a liquid (45a, 45b) from a reservoir and a driving piston (11a, 11b) for the transfer of this liquid to the pre-compression conduit through an intermediate transfer chamber (8a, 8b), the liquids from the two reservoirs by effect of the simultaneous control of the two driving pistons mixing in the pre-compression conduit before exiting through the expulsion orifice (25) to the diffusion head (26).

2. Improvement according to claim 1, characterized in that the pre-compression pump is associated with two reservoirs (42a, 42b) each containing a different liquid (45a, 45b).

3. Improvement according to claim 1, characterized in that one of the reservoirs is removed, the corresponding compression chamber (5a) communicating directly with the outside air to form with the liquid (45b) of the second reservoir (42b) an emulsion in the pre-compression conduit (6).

4. Improvement according to claim 3, characterized in that the pre-compression conduit (6) comprises beyond the expulsion orifice (25) a screw (51) with helical thread (52), mounted for rotation in a bore (53) of the diffusion head (26) in order to achieve the emulsion of the air and the liquid.

5. Improvement according to any one of claims 1 to 4, characterized in that the liquid reservoirs (42a, 42b) are made up of flexible pouches, made of plastic material, metal-plastic composite, or metal, capable of deforming as liquids (45a, 45b) are drawn from these pouches.

6. Improvement according to claim 5, characterized in that the flexible bags (42a, 42b) are screwed or snapped, or welded or otherwise fixed, to the end of the compression chambers (5a, 5b), at the sampling orifices (13a, 13b).