[0001] The invention relates to a cap for an aerosol can provided with an outer shell, which
is at one end provided with an upper wall extending perpendicularly to the outer shell,
on which the upper end of an inner shell surrounded by said outer shell joins, the
length of the inner shell being less than the length of the outer shell, measured
in a direction perpendicularly to the upper wall, and the inner shell being provided
with a flange on the inside, at its bottom edge remote from the upper wall, which
flange is designed to engage under a bead forming part of an aerosol can, whilst connecting
means are provided between at least two substantially diametrically opposed and resiliently
compressible parts of the outer shell and the inner shell, said connecting means joining
on the inner shell in two at least substantially diametrically opposed points.
[0002] With a known cap of the above kind the flange engaging under the bead forming part
of the aerosol can extends circumferentially over 360°. In order to be able to detach
the cap from the aerosol can it will be necessary to exert forces directed towards
the centre of the outer shell on the two resiliently compressible parts of the outer
shell, in order to deform the inner wall in such a manner that the flange can be wrested
from the bead of the aerosol can.
[0003] This known cap, which is designed with a view to obtaining an attachment of the cap
to the aerosol can such that it is practically impossible for small children to remove
the cap from the aerosol can, is satisfactory per se. The forces which must be exerted
thereby on the opposed resilient parts of the outer shell are so great, however, that
removing the cap may be difficult, in particular for older people.
[0004] The object of the invention is to obtain a cap of the above kind, whereby the requirements
of a so-called "child-proof" cap are still met, but whereby slightly less physical
effort is be expended in removing it from the can.
[0005] According to the invention this may be achieved in that recesses are provided in
the bottom edge of the inner shell, near the points of joining of the connecting means
on the inner shell, in such a manner that the flange provided on the inside of the
inner shell is interrupted near the points of joining. When using the construction
according to the invention the flange will only extend over two approximately diametrically
opposed parts of the inner shell, therefore, which parts will be moved apart when
a compression force is exerted on the resiliently compressible parts of the outer
shell. By using the construction according to the invention the object aimed at can
thus be achieved in a very simple manner.
[0006] The invention will be explained in more detail hereafter with reference to an embodiment
of the construction according to the invention illustrated in the accompanying Figures.
[0007] Figure 1 is a schematic view of an upper part of a conventional aerosol can.
[0008] Figure 2 is an elevational view of a cap according to the invention.
[0009] Figure 3 is a cross-sectional view of the cap according to the invention.
[0010] Figure 4 is a cross-sectional view of the cap according to the invention, perpendicularly
to the cross-sectional view of Figure 3.
[0011] Figure 5 is a bottom view of the cap according to the invention.
[0012] The cap according to the invention is designed for use in combination with a conventional
aerosol can 1. Such an aerosol can comprises a cylindrical shell 2, to which a more
or less dome-shaped cover 3 is secured by means of a bead 4. A valve mechanism 6 is
attached to the upper end of said dome-shaped cover 3 by means of a bead connection
5. The contents of the aerosol can 1 may be discharged in a usual manner by operating
said valve mechanism 6. In order to prevent undesirable use, in particular by children,
a cap yet to be described in more detail hereafter, which surrounds the valve mechanism
6, may be placed on the aerosol can 1, the construction of said cap being such that
normally it cannot be removed from the aerosol can 1 by children.
[0013] As is shown in more detail in Figures 2 - 5 said cap comprises a substantially cylindrical
outer shell 7, on the upper end of which an upper wall 8 extending perpendicularly
to the central axis of the outer shell joins. The shell 7 surrounds an inner shell
9, which is arranged concentrically with respect to the shell 7 and which joins the
upper wall 8 with its upper end. As is apparent from Figures 3 and 4, the length of
the inner shell 9, measured from the upper wall 8, is less than the length of the
outer shell 7, so that the lowermost part of the outer shell 7 projects from the bottom
side of inner shell 9. The outer shell 7 is provided with a plurality of reinforcing
ribs 10 on the inside. Furthermore the outer shell 7 includes inwardly staggered wall
parts 11 in two radially opposite parts, in which U-shaped slots 12 are formed. As
will be apparent in particular from Figure 2, such a U-shaped slot 12 bounds a lip-shaped
part 13, which joins on the other part of the wall portion 11 at a point located some
distance below the upper wall 8.
[0014] As will be apparent from Figure 5, the inner shell 9 as well as the outer shell 7
have a substantially circular section, but near the inwardly staggered wall parts
11 of the outer shell the inner shell 7 is provided with trough-shaped, curved protrusions
14 projecting outwards relative to the other parts of the inner shell and extending
in the longitudinal direction of the inner shell. Said protrusions 14 are connected
to the centres of the tongues 13 by means of connecting ribs extending radially relative
to the central axis of the cap.
[0015] As is furthermore apparent in particular from Figures 3 and 4, recesses 16 extending
through a circumferential angle of ± 45 - 60° are provided in the lower part of the
inner shell, near the protrusions 14 and the connecting means 15 connected to the
centres of said protrusions, so that the inner shell 13 is provided with two diametrically
opposed strip-shaped parts 17, which project below the other part of the inner shell,
said parts 17 at their lower boundary edges being provided with internal projecting
flange parts 18, which concentrically surround the central axis of the cap.
[0016] When the above-described cap is placed on an aerosol can of the type shown in Figure
1, the flange parts 18 will move slightly outwards under resilient deformation of
the inner shell 9 when pushing on the cap, so that said flange parts can snap under
the bead 5.
[0017] In order to remove the cap a force must be exerted in the direction according to
arrow A on the lips 13, which are resiliently movable in inward direction relative
to the other part of the outer shell 7. Forces exerted on the lips 13 in the direction
according to arrow A will be transmitted to the protrusions 14 of the inner shell
9 via the connecting means 15, as a result of which said diametrically opposed parts
14 of the inner shell will be forced towards each other, which results in a resilient
deformation of the inner shell 9 such that the diametrically opposed flanges 18 will
move in a direction away from each other. Then the cap can be wrested from the aerosol
can.
[0018] Due to the described configuration of the inner shell 9 and the diametrically opposed
recesses 16 provided therein less force is required for deforming and pulling off
the cap from the bead 5 of the aerosol can than with the constructions that have been
usual so far.
1. A cap for an aerosol can provided with an outer shell, which is at one end provided
with an upper wall extending perpendicularly to the outer shell, on which the upper
end of an inner shell surrounded by said outer shell joins, the length of the inner
shell being less than the length of the outer shell, measured in a direction perpendicularly
to the upper wall, and the inner shell being provided with a flange on the inside,
at its bottom edge remote from the upper wall, which flange is designed to engage
under a bead forming part of an aerosol can, whilst connecting means are provided
between at least two substantially diametrically opposed and resiliently compressible
parts of the outer shell and the inner shell, said connecting means joining on the
inner shell in two at least substantially diametrically opposed points, characterized
in that recesses are provided in the bottom edge of the inner shell, near the points
of joining of the connecting means on the inner shell, in such a manner that the flange
provided on the inside of the inner shell is interrupted near the points of joining.
2. A cap according to claim 1, characterized in that a recess in the inner shell extends
through a circumferential angle of ± 45 - 60°.
3. A cap according to claim 1 or 2, characterized in that a recess provided in the bottom
end of the inner shell is provided near an outward protrusion of the inner shell extending
along the height of the inner shell.
4. A cap according to claim 3, characterized in that a protrusion is connected to a resiliently
compressible part of the outer shell by means of an at least substantially radially
extending connecting rib.
5. A cap according to any one of the preceding claims, characterized in that a resilient
part of the outer shell is made up of a U-shaped lip cut out of the outer shell, which
is only connected to the other part of the outer shell at one end.