Double-wall aerosol container

Abstract: In a double-wall aerosol container having a jacket (1) and an inner bag (10) to be applied within said jacket, wherein a content in said inner bag is sprayed outside thereof via a valve mechanism by pressurizing said inner bag with a propellant charged in said jacket, said double-wall aerosol container is characterized by: a jacket (1) provided at the bottom thereof with a charging valve (4) for charging a propellant into said jacket and also with an annular packing (8) placed to engage with the upper side of the engagement ridge (6) on the inner peripheral surface of said jacket; an inner bag (10) provided with a thick flange (13) formed around the opening edge thereof with the annular packing (8) being applied on the lower surface of said flange, and also provided with a storage section (12) being connected to said flange and which can be deformed or deflated by a pressure of said propellant charged in said jacket; a housing (16) having an inner frame (17) inserted along the inner peripheral surface of the opening edge (15) of said inner bag, and an annular rib (18) formed to protrude from the circumference of the upper end portion of said inner frame and placed on the upper end face of the flange (13) of said inner bag, said housing being also incorporated with a valve mechanism (28); and a cover (30) which is formed by folding inward the upper end portion of said jacket to fix and cover the upper surface of said housing, with a stem (22) of said valve mechanism protruding from the center of said cover.

Description: The present invention relates to a double-wall aerosol container according to the preamble of claim 1, comprising a jacket and an inner bag formed therein such that the inner hag may be communicable to a nozzle, and a content, which should preferably be avoided from contact with a propellant, is charged to the inner bag and is adapted to be sprayed without being brought into contact with the propellant by pressurizing the inner bag from the outside thereof. It has conventionally been employed in a technique for spraying an aerosol content, to apply a deflatable inner bag in a jacket of an aerosol container, with a propellant being charged in the space outer than this inner bag so as to prevent the content from being in contact with the propellant, and to allow the inner bag to be pressurized by the propellant to spray the content with the aid of this pressure. In such a technique, as described in Japanese Utility Model Publication Nos. Hei 5-32221 and 6-32863, and in Japanese Unexamined Patent Publication No. Hei 2-218461, the inner bag is connected to the jacket by an annular engagement ridge formed to protrude inward from the inner peripheral surface of the jacket at an upper position. The upper part of the inner bag is partly brought into contact with this engagement ridge, and the thus contacted part of the inner bag is pressed against the inner surface of the engagement ridge by the outer circumference of a housing, thus achieving fixing between the inner bag and the jacket. That is to say, the fixing of the inner bag to the inside of the jacket according to the prior art, as described above, is achieved by nipping the upper end portion of the inner bag which is as thick as the thin deflatable storage section between the housing and the jacket so as to secure the inner bag to hang in the jacket with the aid of this nipping force. Accordingly, when the inner bag is to be applied in the jacket in the production process, it is difficult to engage and retain the inner bag within the jacket, so that the inner bag must be retained in the jacket using a special tool and the like. With the inner bag being retained by the tool, the housing must be inserted through the opening of the jacket to allow the upper end portion of the inner bag to be nipped securely between the outer peripheral surface of the housing and the inner peripheral surface of the jacket. It requires a great many of procedures and thus not preferred in the aspect of workability to apply the housing after the inner bag is engaged with the inner peripheral surface of the jacket, as described above. Under such circumstances, it is also attempted to secure the upper end portion of an inner bag to the outer peripheral surface of a housing and to apply the resulting housing in the jacket. However, in order to secure the upper end portion of the inner bag to the outer peripheral surface of the housing beforehand, an extra constitution is required for securing the inner bag, and also the procedures of securing the inner bag in the pretreatment step therefore must be added, requiring quite many procedures. In addition, when the inner bag integrated with the housing is to be inserted to the jacket, the soft inner bag is often inadvertently brought into contact with the rigid housing in that process to damage the inner bag and to require an increased number of procedures in the assembly operation, disadvantageously. Further, since the upper end portion of the thin inner bag is to be nipped securely between the outer peripheral surface of the housing and the inner peripheral surface of the jacket even after completion of assembly, the inner bag often breaks at the nipped portion or slips out of position. The present invention is directed to solve the problems described above, and it is an object of the present invention to enable application of an inner bag in a jacket without using any special tool and the like and then fitting of a housing of an aerosol container in the opening edge of the thus applied inner bag without damaging the inner bag, as well as, to prevent the inner bag from slipping off into the jacket after application or from being damaged during use or assembling process. The above mentioned object has been solved by the features of claim 1. In this case, the storage section of the inner bag may be formed to have a tubular form, or may be formed to have a plurality of vertical and parallel accordion pleats oriented radially along the peripheral surface thereof. Such a storage section as formed to have a tubular form with vertical and parallel accordion pleats oriented radially will allow smooth deflation or deformation of the inner bag even when the thickness of the inner bag is subtly uneven, and thus the content is prevented from remaining unused in the inner bag, enabling economical use of the content. Since the constitution of the present invention is as described above, the storage section of the inner bag in which a content is to be contained can readily be deformed by the pressure of the propellant. Meanwhile, a flange which is thicker than the storage section is formed at the upper part of the inner bag, and an annular packing is disposed under the flange. Accordingly, the annular packing can be brought into engagement with the upper side of the engagement ridge formed on the jacket. Further, in this engagement onto the upper side of the engagement ridge, the inner bag can extremely stably be engaged on the upper side of the engagement ridge because of the thick flange provided on the inner bag. The assembly operation procedures are that the inner bag is inserted into the jacket through the upper opening thereof, and thus the flange of the inner bag can be engaged with the upper side of the engagement ridge via the annular packing. The thus achieved engagement of the flange of the inner bag with the engagement ridge via the annular packing prevents the inner bag from slipping off into the jacket or out of position, and the inner bag can stably be retained in the jacket. In the subsequent operation step, the housing is inserted to the upper end opening of the jacket. The housing is provided with a cylindrical inner frame formed at the lower end thereof, and the thus formed inner frame is inserted along the inner periphery of the flange of the inner bag, and the annular packing is pressed, with the aid of this pressure of insertion, against the upper side of the engagement ridge formed on the jacket, thus maintaining airtightness. The annular packing may be fitted partly in an annular groove formed on the outer peripheral surface of the inner bag at a position corresponding to the lower part of the thick flange. The annular packing as inserted in an annular groove will have a stabilized position for mounting the annular packing itself, so that it does not provide any poor airtightness. However, if accuracy is secured in assembling members, the above-described annular groove is not always necessary. The annular rib may be placed on the upper end face of the flange of the inner bag via a gasket. Thus if a gasket is disposed on the upper end face of the flange, the annular rib of the housing can be brought into press contact with this gasket to ensure sealability at this section. Accordingly, the content is prevented from leaking out through the contact section between the inner frame and the flange of the inner bag. However, if the flange is made of a soft and elastic material, the flange also serves as the gasket, so that the gasket is not always necessary. The cover covering the upper surface of the housing can immobilize the valve mechanism, including the stem and stem gasket together, to be housed in the housing, and thus the valve mechanism can be handled as one member in the operation of incorporating the mechanism into the jacket, improving workability. In the double-wall aerosol container thus constituted, if the valve mechanism is let open according to a known technique by pushing the stem, the internal space of the inner bag is allowed to communicate to the nozzle for spraying the content. Since the inner bag is constantly pressurized by the pressure of the propellant charged between the outer peripheral surface of the inner bag and the inner peripheral surface of the jacket, the content in the inner bag flows into the housing without being brought into contact with the propellant to be sprayed out through the nozzle via the valve mechanism. The inner bag can gradually be deformed to reduce volume as the content is sprayed continuously. The thick flange of the inner bag is engaged via the annular packing with the upper side of the engagement ridge formed on the jacket, so that the engagement of the inner bag with the jacket is securely achieved, causing no slipping of the inner bag into the jacket. Slipping off of the inner bag can also be effectively prevented effectively, not only when the inner bag is inserted into the jacket in the assembling process, but also when the final product is used after completion of assembly. The content of the invention is not limited to the above description, and the objects, advantages, features, and uses will become apparent by reference to the following description considered in connection with the accompanying drawings. Additionally, it should be noted that any appropriate alterations not departing from the scope of the invention as disclosed in the appended claims are to be included in the scopes of the invention. Fig. 1 shows in upper cross-sectional view a double aerosol container one embodiment of the present invention; Fig. 2 shows in cross-sectional view an aerosol container according to one embodiment of the invention; Fig. 3 shows in cross-sectional view, an inner bag having accordion pleats formed radially; and Fig. 4 shows a cross-sectional view taken along the line A-A of Fig. 3. A preferred embodiment of the present invention is now being described in accordance with a preferred embodiment referring to the attached drawings. A jacket 1 made of a metal is formed by connecting and securing thereto a bottom plate 2 also made of a metallic material at the lower end of the jacket 1 via a rolled portion 3. The bottom plate 2 is provided at the center thereof with a charging valve 4 which is used for charging a propellant into the jacket 1. The charging valve 4 may be made of rubber and fitted in a charging port 5 defined in the bottom plate 2 immediately after the propellant is charged into the jacket 1 so as to prevent leakage of the propellant. Alternatively, the propellant may be charged using a charging nozzle (not shown) which is allowed to stick through the rubber charging valve 4, and after completion of charging, the charging nozzle penetrating the valve 4 may be withdrawn to close the hole formed by penetration of the nozzle by the self restoring force of the rubber charging valve 4. Otherwise, the charging valve 4 may be of any arbitrary structure such as of a check valve. An annular engagement ridge 6 protrudes inward from the inner peripheral surface of the jacket 1 at an upper part thereof. An annular packing 8 being an O ring is fitted and applied on the upper side 7 of this engagement ridge 6. The annular packing 8 is also adapted to be fitted in an annular groove 11 provided on the outer peripheral surface of an inner bag 10 at an upper position thereof. By fitting the annular packing 8 in the annular groove 11, as described above, the annular packing 8 can stably be fitted in position, causing no problem in the airtightness of the container. However, the annular groove 11 is not always necessary, provided that accuracy in assembling the parts can be secured. Besides, the inner bag 10 is also provided, toward the lower end thereof, with a storage section 12 in which a content to be sprayed can be stored. The storage section 12 is formed using a material, for example, a metal foil such as of aluminum or a soft and elastic resin film, and a constitution such that the storage section 12 may readily be deformed when pressed by the pressure of the propellant charged in the jacket 1. The storage section 12 is formed to have a tubular form and has a closed bottom. Meanwhile, the inner bag 10 is provided with a thick flange 13, i.e. the flange is thicker than wall thickness of the storage section 12 and is formed above the annular groove 11. Moreover, the flange 13 is designed to be engaged stably with the upper side 7 of the engagement ridge 6 via the annular packing 8. Further, a gasket 14 is disposed on the upper end face of the flange 13 of the inner bag 10. However, if the flange 13 is made of a soft and elastic material, this gasket 14 is not always necessary, because the flange 13 also serves as the gasket 14. An inner frame 17 of a housing 16 is inserted along the inner peripheral surface of the opening edge 15 of the inner bag 10. The flange 13 of the inner bag 10 and the annular packing 8 can stably be pressed against the inner surface of the jacket 1 by the inner frame 17 inserted to the opening edge 15. Since an annular rib 18 protrudes from the upper end of the housing 16, and the annular rib 18 is placed such that the lower surface thereof is in contact with the upper surface of the gasket 14 or directly with the flange 13 made of a soft and elastic material, the content is prevented from leaking out through the contact section between the inner frame 17 and the inner surface of the inner bag 10. An annular protrusion 20 for securing airtightness is provided on the lower surface of the annular rib 18, at the contact section between the annular rib 18 and the gasket 14 or flange 13, in order to further enhance airtightness of the gasket 14 or flange 13. A stem 22 is inserted at the lower end portion thereof into the housing 16, and the stem 22 is urged outward by a helical compression spring 21. An orifice 23 formed on the side wall of the stem 22 is normally closed or stopped by a stem gasket 24, and the closing of the orifice 23 by the stem gasket 24 is released by pushing down the stem 22 into the housing 16 to allow communication between the inside and outside of the housing 16 through this orifice 23. An inlet 25 is formed on the side wall of the housing 16 inserted in the inner bag 10, so that the content in the inner bag 10 may be introduced into the housing 16. A cover 26 made of a metallic material such as stainless steel is applied on the upper surface of the annular rib 18 of the housing 16, and the cover 26 is tightly fixed onto the outer peripheral surface of the annular rib 18 of the housing 16. The thus fixed cover 26 integrates and immobilizes the helical compression spring 21, stem 22, stem gasket 24, etc. in the housing 16 to facilitate handling of the housing 16 in assembling an aerosol container 27. Meanwhile, the helical compression spring 21, stem 22, stem gasket 24, etc. constitute a valve mechanism 28 of the aerosol container 27. In order to fabricate the aerosol container 27 thus constituted, the inner bag 10, with or without a content charged therein, is first inserted into the jacket 1 through an upper end opening 29 thereof. The inner bag 10 is inserted from the storage section 12 thereof, and the annular packing 8 is allowed to engage with the upper side 7 of the engagement ridge 6 of the jacket 1. In this insertion process, the inner bag 10 pushes the annular packing 8 against the upper side 7 of the engagement ridge 6 to achieve engagement therewith, and the thick flange 13 provided on the inner bag 10 facilitates stable application of the inner bag 10 into the jacket 1. Accordingly, it does not happen that the inner bag 10 slips off into the jacket 1 or out of position in this stage to provide poor airtightness. Next, the housing 16 incorporated with the valve mechanism 28 is inserted into the jacket 1 through the upper end opening 29 thereof, and the inner frame 17 of the housing 16 is inserted along the side of the inner peripheral surface of the flange 13 of the inner bag 10. Thus, the annular packing 8 and the flange 13 are securely pushed against the inner surface of the jacket 1 to bring the annular packing 8 into intimate contact with the upper side 7. Simultaneously, the gasket 14 placed beforehand on the upper end face of the flange 13 or the flange 13 made of a soft and elastic material is brought into contact with the lower surface of the annular rib 18, so that the content can be prevented from leaking upward through the contact section between the inner frame 17 and the inner surface of the inner bag 10. Since the gasket 14 is also brought into contact with the inner peripheral surface of the jacket 1, leakage of the propellant upward beyond the annular packing 8, if any, can securely be prevented. As described above, after the housing 16 is applied into the jacket 1, the upper end portion 30 of the jacket 1 is folded inward to be secured onto the upper surface of the cover 26, and thus the aerosol container 27 is completely assembled. Next, when the inner bag 10 is not charged beforehand with a content, the content can be charged into the inner bag 10 by filling the content thereof under pressure through the stem 22. Then, a propellant is charged into the jacket 1 through the charging valve 4 or charging port 5 provided on the bottom plate 2, and the charging port 5 is closed with the charging valve 4, completing production of the aerosol container 27. The inner bag 10 is formed into a tubular form using a flat film, an aluminum foil, etc. in the above embodiment. However, according to another embodiment, the inner bag 10 may have a plurality of parallel accordion pleats 31 formed by folding the inner bag 10 vertically along the storage section 12 thereof to be oriented radially, as shown in Figs. 3 and 4. Thus, by forming the accordion pleats 31 radially along the storage section 12 of the inner bag 10 having a closed bottom, deflation or deformation of the inner bag which occurs as the content is sprayed can efficiently be achieved, so that the portion of the content finally remaining unused in the inner bag 10 can be minimized. That is to say, when the inner bag 10 is allowed to have a simple tubular form, the inner bag 10 is liable to undergo irregular deflation as the content is sprayed if there is any delicate unevenness in the thickness thereof to cause some portion of the content to remain unused therein. However, by forming accordion pleats radially along the circumference of the storage section 12 of the inner bag 10, as shown in Figs. 3 and 4 in this embodiment, deflation or deformation of the inner bag 10 can smoothly be achieved even if it has delicate unevenness in the thickness etc. thereof, and thus the content is prevented from remaining unused in the inner bag 10, enabling economical use of the content. The constitution of the present invention is as described above. Accordingly, a soft inner bag can extremely stably be applied into a jacket when a double-wall container is to be fabricated, and it does not happen that the inner bag slips off into the jacket in the process that the inner bag is applied. Further, when the double-wall container is used as a final product obtained after completion of assembly, the accident that the inner bag slips off into the jacket to make the content unusable can securely be prevented.

Claims: A double-wall aerosol container comprising: a jacket (1) containing an inner bag (10) and having a bottom plate (2) and an annular engagement ridge (6), said bottom plate (2) being provided with a charging valve (4) for charging a propellant into said jacket and said engagement ridge (6) being protrudingly provided on an upper inner peripheral surface of said jacket; an annular packing (8) being engageably placed on an upper surface side (7) of said engagement ridge (6); said inner bag (10) being provided with a flange (13) formed outwardly around the opening edge (15) thereof with said annular packing (8) being applied on the lower surface of said flange, and further provided with a storage section (12) being connected to said flange and being deformable or deflatable by the pressure of said propellant charged into said jacket; a housing (16) having an inner frame (17) inserted along the inner peripheral surface of the opening edge (15) of said inner bag (10) and an annular rib (18) formed to protrude from the circumference of the upper end portion of said inner frame (17) and placed on the upper end face of the flange (13) of said inner bag, and further a valve mechanism (28) for spraying outside the content of said inner bag (10); a cover (26) for covering an upper surface of the housing (16), said cover allowing at a center portion thereof a stem (22) of said valve mechanism (28) to protrude outwardly, and an upper surface of said cover being fixed by bending an upper end portion (30) of said jacket (1); said flange (13) being fixedly held between the upper surface of said annular packing (8) and the lower surface of said annular rib (18) characterized in that said flange (13) of said inner bag (10) is thicker than the wall thickness of the storage section (12). The double-wall aerosol container according to Claim 1, characterized in that said inner bag (10) is provided on the outer peripheral surface thereof with an annular groove (11) at a position corresponding to the lower part of said thick flange (13), and said annular packing (8) is fitted partly in said annular groove. The double-wall aerosol container according to Claim 1, characterized in that said annular rib (18) is placed on the upper end face of the flange (13) of said inner bag via a gasket (14). The double-wall aerosol container according to Claim 1, characterized in that the storage section (12) of said inner bag (10) is formed to have a tubular form. The double-wall aerosol container according to Claim 1, characterized in that the storage section (12) of said inner bag (10) is formed to have a plurality of vertical and parallel accordion pleats (31) oriented radially along the circumference thereof.

Inventors: HOSHINO KAZUNORI, MITSUI TOSHIYUKI, YAZAWA IWAO, HOSHINO, KAZUNORI, MITSUI, TOSHIYUKI, YAZAWA, IWAO
Applicants: TOYO AEROSOL IND CO, TOYO AEROSOL INDUSTRY CO., LTD.
Application year: 1995
Main classification: B65D83
IPC codes: B65D83, B65D77