US 3460708 A
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G. L. VOLLERS Filed April 29, 1968 IN VEN T02 602v l I/ZmLE/es DESTRUCTIBLE CAP FOR AEROSOL CONTAINERS Aug. 12, 1969 lira 1.
United States "Patent U.S. Cl. 220-27 8 Claims ABSTRACT OF THE DISCLOSURE The disclosure concerns an unusually effective tamperproof, protective cover for the valve controlling dispensing outlet of an aerosol can.
BACKGROUND OF THE INVENTION This invention relates generally to protective covers for containers, and more particularly concerns an unusually effective, tamper-proof, protective cover for the valve controlled dispensing outlet of an aerosol can.
Aerosol cans have come into wide use for dispensing liquid substances such as paint, insecticides, sprays and many other materials. Such dispensing is typically con trolled at the top of the can by a finger operated valve, which is readily operated. To protect the valve against tampering during merchandising, protective caps have been devised; however, in the past such caps have suffered from certain disadvantages. Among these are the ease of pul1-off removal of some caps, and the relative ease of disconnecting others from the can, as by simply spreading a connection holding the cap to the can collar. These and other factors have prevented attainment of an easyto-manufacture and simply applied cap which is truly tamper-proof.
SUMMARY OF THE INVENTION It is a major object of the invention to resolve the problems referred to above, through the provision of a cap of unusually effective construction, mode of operation, and tamper-proof result. Basically, the cap is of one piece molded plastic design and comprises an outer skirt defining an upright central axis and having a lower rim receivable relatively downwardly in an upwardly opening annular recess at the top of the can; a can top integral with the skirt to extend over an upper annular collar on the can as well as over the valve controlled outlet; and multiple legs integral with and projecting downwardly from the can top with circular spacing about the cap axis, the legs having lower portions engageable with the collar to resiliently flex the legs away from the axis and such portions also having shoulders facing upwardly and projecting inwardly to snap under the collar as the cap is assembled on the can. Further, the cap skirt has a notch to receive insertion of a prying implement engageable with the can and skirt to lift the cap, the legs being dimensioned to fracture in response to such lifting relative to the can. As a result, it is only through such extreme prying that fractures the cap that access can be gained to the valved outlet, whereby that outlet remains tamper-proof before such cap destruction.
Additional advantages and features of the cap construction include the provision for resilient downward flexing of the cap top when the shoulders are snapped under the collar, such flexure placing the legs in tension to hold the skirt tightly downwardly against the can top; the reduction in dimension of the leg lower portions to predetermine the loci of leg fracturing; and the location of the pry-notch well below the legs so that the legs cannot be tampered with through manipulation of a tool inserted through the notch.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following detailed description of the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an exterior elevation showing a cap incorporating the invention assembled to a container or can;
FIG. 2 is an enlarged elevation taken in section, showing the cap during a stage of its assembly to the can;
FIG. 3 is a view like FIG. 2, but showing the cap fully assembled to the can;
FIG. 4 is a horizontal section taken on line 4-4 of FIG. 3;
FIG. 5 is a view like FIG. 3, but showing fractureremoval of the cap; and
FIG. 6 is a perspective view of a leg integral with the cap.
DESCRIPTION OF PREFERRED EMBODIMENT A typical aerosol spray can 10, to which the cap 11 of the invention is applicable, includes a body 12, domed cover 13, collar 14, and finger controllable spray nozzle 15. FIG. 3 illustrates an upwardly opening annular recess 16 formed by the head 17 at the outer portion of cover 13. Recess 16 may typically be at a lower level than collar 14.
The one-piece molded plastic cap comprises a thin wall outer skirt 18 defining an upright central axis 19 and having a lower rim or edge 20 receivable relatively downwardly in the recess 16, as seen in FIG. 3, to seat the cap on the can. The cap also has a thin Wall top 21 integral with the skirt to extend over the collar 14 and valved outlet 15. Further the top is resiliently flexible, as indicated by comparison of FIGS. 3 and 5 with FIG. 2, for purposes to be described.
In addition, the cap includes multiple (as for example three) legs 22 integral with and projecting downwardly from the cap top 21 with circular spacing about axis 19. The legs have lower portions 22a engageable with the collar, as seen in FIG. 2, to resiliently flex the legs away from the axis 19 (as indicated by broken lines 23), during assembly of the cap onto the can. As the portions 22a drop downward over the collar, they ultimately snap inward under the spring action afforded by the outwardly flexed legs, and to positions as seen in FIG. 3. In this regard, the portions 22a have lips or shoulders 24 facing upwardly and projecting inwardly to snap under the collar for retaining the cap on the can. Shoulders 24 need only have small radial dimension, as example less than .040" and preferably about .020, to assure desired retention while accommodating ease of molding.
Note in FIG. 3 that the shoulders 24 have spacing from the cap top 21 such that the top is typically resiliently flexed downwardly when the shoulders 24 are snapped under thegcol-lar 14. Such top flexure places the legs in tension to hold the skirt seated tightly downwardly against the can top. At the same time, the legs 22 remain slightly flexed to maintain the shoulders 24 under the collar, whereby ordinary manual pulling on the cap cannot remove it from the can and the valved outlet 15 remains tamperproof.
In order to remove the cap from the can it must be pried upwardly with sufficient force to produce fracturing, as will now be described. It will be noted that the skirt 18 forms a notch 25 sized to receive insertion of a prying tool 26 (as for example a key or screwdriver) in such manner as to engage the can and skirt with sufiicient leverage and mechanical advantage to forcibly lift the cap. FIG. 5 illustrates pivoting of the tool 26 about the fulcrum afforded by the edge of bead 17, the tool engaging the skirt edge 27 defining the upper limit of the notch. That edge 27 is sufficiently inward of the bead edge and spaced slightly above the upper level of the bead edge as to enable the prying action to fracture at least one of the legs 22, close spacing of edge 27 to the fulcrum edge of the bead further affording the considerable mechanical advantage of the prying action to produce the fracture.
Note further that while the main bodies of the legs 22 may have considerable angular extent (each around 100 for example) about axis 19, for ease of molding and to resist flexing, they are dimensioned to fracture in response to such prying action. For this purpose, the leg lower portions 22a, or feet, have reduced angular dimensions about axis 19, as is clear from FIG. 6, and sufficient to predetermine the loci of fracture at such lower portions. See in this regard the fracturing at 29 in FIG. 5 In this regard, the thickness of the cap top 21 is sufficient to permit downward flexing for leg attachment to collar, but insufficient to prevent (as by top flexing) fracture of the legs, as described, within the limits of prying motion afforded by the relationship of the notch 25 to the head 17. After such sudden fracturing, the cap may easily be lifted off the can. Thereafter, the cap may be reapplied to the can, the inner sides of the legs frictionally gripping the collar for removably holding the cap on the can.
From consideration of the following, it is clear that the cap 11 has unusually advantageous construction, purpose and mode-of-operation in relation to the can, producing unusually effective tamper-proofing of the can.
Typical plastics that may be used in molding the cap are polyolefins such as polyethylene (high density for example), polypropylene, and polystyrene (high impact styrene and general purpose styrene for example), and copolymers of olefins, particularly styrene copolymers (such as ABS and SAN).
1. A one-piece molded plastic protective cap for an aerosol can having a valve controlled upper outlet, an upper annular collar, and an upwardly opening annular recess at a lower level than said collar and of a diameter substantially greater than the collar diameter, said cap comprising an outer skirt defining an upright central axis and having a lower rim receivable relatively downwardly in said recess to engage the can and support the cap,
a cap top integral wtih the skirt to extend over said collar,
and multiple legs integral with and projecting downwardly below the cap top with circular spacing about said axis, the legs being outwardly flexible away from said axis and having lower portions free to be simultaneously outwardly displaced away from said axis and which are engageable with the collar to resiliently flex the legs away from said axis and said portions having shoulders facing upwardly and projecting inwardly to snap under said collar as the cap is assembled on the can,
the cap skirt having a notch sized to receive insertion of a prying implement engageable with the can and skirt to forcibly lift the cap, and said legs being dimensioned to fracture in response to such lifting relative to the can.
2. The cap as defined in claim 1 wherein said shoulders have spacing from said top such that the top is resiliently flexed downwardly when said shoulders are snapped under said collar, cap top downward flexure placing the legs in tension to hold the skirt tightly downwardly against the can top.
3. The cap as defined in claim 1, and including said can to which the cap is assembled.
4. The cap as defined in claim 2, and including said can to which the cap is assembled with said top resiliently flexed downwardly to have upwardly facing concavity.
5. The cap as defined in claim 1, wherein said lower portions of the legs have sufficiently reduced dimensions about said axis relative to the main portions of the legs thereabove, as to predetermine the loci of said fracturing at said lower portions.
6. The cap as defined in claim 1 wherein said skirt defines the upper limit of said notch at a level spaced substantially below the levels of said collar and the lowermost extents of said legs.
7. The cap as defined in claim 1 wherein said plastic consists of polyolefins and copolymers thereof.
8. The cap as defined in claim 1 wherein all of said notch is spaced below the lowermost level of said legs.
References Cited UNITED STATES PATENTS 3,097,758 7/1963 Gersher 220-27 3,149,745 9/ 1964 Edelatone 2206O 3,322,298 5/1967 Gach 220-6 3,369,712 2/ 1968 Osrow 222-182 GEORGE E. LOWRANCE, Primary Examiner US. Cl. X.R.