Vented Curl For Aerosol Dome

Abstract

An aerosol dome having a lower end adapted to be attached to the upper end of a container and having an upper open end surrounded by an outwardly turned wall. The outwardly turned wall has a free edge and an adjacent end portion in overlapping relation with an adjacent outer surface of the aerosol dome to define a curl with an enclosed area having an internal radius. A major circumferential portion of the curl defined by the wall has a substantially constant or fixed internal radius which locates the free edge in contacting engagement with the outer surface of the dome and at least one selected circumferential portion of the curl has a radius at the free edge which is less than the fixed internal radius to space that portion of the free edge from the outer surface and provide a vent opening for the internal area of the curl. BACKGROUND OF THE INVENTION The present invention relates generally to container ends and more particularly to an improved aerosol dome having a vented bead. In the formation of aerosol containers, it is customary to separately form, what is commonly referred to as, an aerosol dome and attach one end of the aerosol dome to the main body of the container. Generally, the aerosol dome has an opening formed at the upper end thereof, which has a diameter less than the diameter of the main body of the container. The upper opening is surrounded by a bead or curl which is formed by an integral outwardly turned wall that is rolled to a substantially circular cross-sectional configuration to form a closed bead. The upper open end is capable of receiving a mounting cup supporting a valve mechanism and the surrounding bead or curl serves as a support for a channel member on the upper end of the mounting cup which is crimped to the container end. In some constructions, the free edge and an adjacent end portion of the outwardly turned wall are placed in overlapping contacting relationship to the adjacent outer surface of the dome to rigidify the entire structure. In many instances, the aerosol container is filled by forcing propellant and product between the adjacent surfaces of the mounting cup and the aerosol dome before the mounting cup is crimped to the bead of the dome. In such a filling operating one practice, which has become customary, is to loosely insert the mounting cup with the valve mechanism secured therein into the open end of the container and, thereafter, place a charging head into sealing engagement with the surface of the aerosol dome at a point spaced from the bead. After a vacuum has been produced within the container, the high pressure low temperature propellant, as well as product, both of which are in a liquid state, are forced between the upper rim of the mounting cup and the adjacent bead on the upper end of the aerosol dome. After the container has been filled to the desired level, the mounting cup is crimped and sealed within the container opening before the charging head is removed. It has been found that during such a filling operation, some of the propellant and product may be forced into the closed internal area of the bead or curl. Thereafter, the propellant, which is in a gaseous state at room temperature and substantially atmospheric pressure, will tend to escape while the filled containers are checked for "leakers." Since, it is customary to immerse the entire container into a heated water bath to detect "leakers," the escape of the gaseous propellant from the internal area of the bead will produce bubbles in the bath resulting in the interpretation that the container is a "leaker." Another problem encountered in having propellant and product trapped in the internal area of the bead is that the product, which is in liquid form at room temperature, will tend to seep from the internal area of the bead while the container is on display. Again, this seepage of product from the internal area of the bead will be interpreted to be leakage from the internal area of the container and will result in having the retailer return the container as being defective or will cause the purchaser to refuse to buy the product because of the unsightly appearance on the surface of the container dome. Thus, there is an urgent need for a simple and effective method for preventing the trapping of propellant and product in the internal area of the bead while still maintaining a bead of sufficient integrity to perform its intended function. BRIEF SUMMARY OF THE PRESENT INVENTION The present invention contemplates the formation of a container end of the type having a peripheral bead or curl surrounding an open end with the bead being defined by an outwardly turned wall having a free end portion which is in overlapping relationship with the adjacent outer surface of the container end. The overlapping relation of the outwardly turned wall and the adjacent outer surface produces a substantially closed area having a substantially constant or fixed internal radius. The present invention contemplates that the major portion of the bead be formed to have a substantially constant or fixed internal radius which will locate the free edge of the overlapping portion in contacting engagement with the outer surface of the container end with at least one selected circumferential portion of the bead having a radius at the free edge which is less than the fixed radius to thereby space the free edge from the outer surface and provide a vent opening for the internal area of the bead. Stated another way, a minor circumferential portion of the bead has a spiral configuration commencing with a minimum radius at the free edge with the radius increasing to substantially the fixed radius of the remainder of the bead at the point spaced from the contacting engagement of the wall With the adjacent surface.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows a fragmentary side elevation of the container end constructed in accordance with the present invention and having a mounting cup and valve mechanism secured therein;

FIG. 2 is an enlarged side elevational view of the dome end of the aerosol container with the mounting cup and valve mechanism removed;

FIG. 3 is a sectional view taken generally along lines 3--3 of FIG. 2;

FIG. 4 is a sectional view taken generally along lines 4--4 of FIG. 2; and

FIG. 5 shows a fragmentary view, similar to FIG. 2, of a slight modification of the present invention.

DETAILED DESCRIPTION

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail, one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.

FIG. 1 of the drawings discloses an upper end of an aerosol container 10 including a main body 12 of the container and an end portion Or aerosol dome 14. The lower end of the aerosol dome 14 is suitably secured to the upper end of the cylindrical body 12 through a sealed joint 16, which may be in the form of a commercially known double seam.

The upper end of the dome 14 has an opening 18 formed therein which is surrounded by a bead 20. In its completely assembled condition, the aerosol container 10 has a mounting cup 22 received in the opening 18 with a downwardly opening annular channel 23 crimped at 24, in sealing engagement with the bead 20 with the mounting cup 22 supporting a valve mechanism 26.

As was indicated above, when utilizing "under-the-cap" filling, it is customary to loosely insert the mounting cup 22 into the opening 18 and thereafter to telescope a charging head over the valve mechanism with the charging head being placed in contacting engagement with the outer peripheral surface of the dome 14 at a point outwardly spaced from the bead 20. A vacuum is then produced within the container and propellant and product are forced into the container between the adjacent surfaces of the upper end of the aerosol dome and the upper end of the mounting cup. AT the higher pressure, both the product and the propellant are in liquid form and will tend to be forced and trapped into the internal area of the closed bead 20. This propellant and product many times will remain trapped within the internal area of the bead 20 after the mounting cup 22 has been crimped and sealed to the aerosol dome 14 and the changing head has been removed. This trapped propellant and/or product within the closed area of the bead is undesirable.

According to the present invention, the above mentioned problems are alleviated by venting the internal area of the bead in a simple and effective manner. Thus, the present invention contemplates rolling selected circumferentially spaced portions to a cross-sectional configuration in which a first segment adjacent the free edge of the outwArdly turned wall is of substantial spiral configuration with the minimum radius of the spiral being located at the free edge. Second segments, or the remainder of the selected circumferentially spaced portions, each are rolled to a substantially constant or fixed radius which is equal to the constant or fixed internal radius of the remainder of the bead. With such an arrangement, the free edge of each of the selected portions is spaced from the adjacent outer surface to vent the internal area of the bead while the remainder of the free edge and the adjacent overlapping end portion of the wall are in contacting engagement with the outer surface to maintain the necessary integrity in the bead 20.

As is more clearly shown in FIGS. 2, 3 and 4, the major circumferential portion of the bead 20 is defined by an integral outwardly turned wall 30 which has a free edge 32 and an adjacent end portion 34 in overlapping relationship with an adjacent outer surface 36 of the main body portion of the dome 14 to define a closed area 38. As shown in FIGS. 2 and 3, the major circumferential portion of the bead 20 has an internal area 38 which is of a substantially constant cross-sectional configurAtion and has a fixed or constant internal radius. However, selected circumferential portions of the wall 30 have a first segment, as shown in FIG. 4, oF a spiral cross-sectional figuration with the minimum radius of the spiral segment being at the free edge 32 So as to space the free edge 32 as well as the overlapping end portion 34 from the adjacent surface 36 oF the dome 14. The first segment encompasses approximately one-fourth of the selected circumferential portion while the remaining or second segment of the selected circumferential portions have a substantially fixed radius which is equal to the substantially constant internal radius of the major portion of the bead.

While not specifically necessary to the present invention, it is contemplated that selected circumferential portions be at diametrically opposed points relative to the open end 18 of the dome 14 with each of the circumferentially spaced selected portions being divided into first and second sections 40 and 42 with an intermediate section 44 which has a cross-sectional configuration corresponding to the cross-sectional configuration of the major portion shown in FIG. 3. By rolling circumferentially spaced and diametrically opposed pairs of sections to the reducing internal radius adjacent the free edge, the forces encountered during such a rolling process will be balanced.

An inspection of FIG. 2 shows that the lower edge of the bead 20 has a substantially serpentine or sinuous configuration. However, the amplitude of the wave defining the lower edge of the selected circumferential portion is extremely small, but is sufficient to place at least the peak above the remainder of the lower edge of the bead and produce a small opening between the adjacent outer surface of the dome.

FIG. 5 is a view similar to FIG. 2 but showing a single small opening being formed on each half of the bead. It will also be appreciated that only one opening for the entire bead is necessary to produce sufficient venting for the entire bead. The cross-sectional configuration of the portion of the bead producing the opening 50 in FIG. 5 is substantially identical to that shown in FIGS. 3 and 4.

Thus, it will be appreciated that the present invention provides a simple and effective manner for venting the internal normally closed area of a bead surrounding an open end of an aerosol dome. Furthermore, the vented bead may readily be formed during the forming process which produces the outwardly curled wall defining the bead.

Claims

What is claimed is:

1. In a domed container end of the type having a dome wall and a peripheral vented curl surrounding an open end and formed by an outwardly turned portion of said wall adjacent a free edge thereof, in which said curl defines a closed area having an internal radius, the improvement in said curl comprising: a segment of said outwardly turned portion adjacent said free edge being overlapped with and in a contoured plane substantially parallel to the adjacent outer surface of said dome wall; said overlapping segment being in contacting engagement with said adjacent outer surface along a major circumferential portion of said curl; said internal radius being reduced at at least one selected circumferential portion extending from said free edge into said closed area to provide a vent opening for said curl.

2. The improvement of claim 1, in which a major portion Of the curl at said at least one selected circumferential portion has an internal radius equal to the internal radius of said curl along said major circumferential portion.

3. The improvement as defined in claim 2, in which the remainder of the curl at said at least one selected circumferential portion has a gradually reducing radius between said major portion of said curl and said free edge.

4. In a domed container end of the type having a dome wall and a peripheral vented curl surrounding an open end and formed by an outwardly turned portion of said wall adjacent a free edge thereof, in which said curl defines a closed area having an internal radius, the improvement in said curl comprising: a segment of said outwardly turned portion adjacent said free edge being overlapped with and in a contoured plane substantially parallel to the adjacent outer surface of said dome wall; said overlapping segment being in contacting engagement with said adjacent outer surface and said internal radius being substantially fixed along a major circumferential portion of said curl; said internal radius at at least one selected circumferential portion being reduced at said free edge and increasing at locations away from said free edge to said fixed internal radius to form a spiral cross-sectional configuration at said at least one selected circumferential portion whereby said free edge at said at least one selected circumferential portion is spaced from said outer surface to place said closed area in communication with the area surrounding said curl.

5. The improvement of claim 4 in which said at least one selected circumferential portion comprises a spaced pair of diametrically opposed sections.

6. In a domed container end of the type having a dome wall and a peripheral vented curl surrounding an open end and formed by an outwardly turned portion of said wall adjacent a free edge thereof, in which said curl defines a closed area having an internal radius, the improvement in said curl comprising: a segment of said outwardly turned portion adjacent said free edge being overlapped with and in a contoured plane substantially parallel to the adjacent outer surface of said dome wall; a major circumferential portion of said curl having a cross-sectional configuration with a constant internal radius placing said free edge in contact with said outer surface; and at least one selected circumferential portion having a first segment of spiral cross-section configuration with the minimum radius of said segment being at said free edge and a second segment with a substantially fixed radius equal to said constant internal radius whereby the free edge of said selected circumferential portion is spaced from said outer surface to vent the closed area of said curl to the atmosphere.

7. An aerosol dome as defined in claim 6, in which said at least one selected circumferential portion comprises first and second pairs of sections, said pairs of sections being in diametrically opposed relation relative to said open end and each pair having an intermediate section of cross-sectional configuration corresponding to said major portion.