Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION OF THE PRIOR ART
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Field of the Invention
This invention relates to fluid sprinkling and more particularly to
an apparatus and method of forming a fluid tight seal between a mount-
ing cup and an aerosol container.
Background Art
The aerosol industry has undergone dramatic and substantial
changes since the birth of the industry many decades ago. It has been
a constant desire of the aerosol industry to increase the reliability of
the aerosol devices while simultaneously reducing the manufacturing and
the consumer costs of the aerosol device. Each individual part of the
aerosol device has been investigated in an attempt to reduce the part
cost as well as the cost of assembly of the aerosol device. The time
required to fabricate each individual par~ as well as time required to
fabricate the device, has been investigated in a continuing attempt to
further reduce the cost of aerosol devices. If a single step in the
assembly process can be accomplished in a shorter period of time, a
substantial reduction in overall cost will be reali~ed by the increase in
production .
Among the most time consuming steps in the fabrication of an
aerosol valvè is the application of a sealing gasket material to the
aerosol mounting cup for sealing with the aerosol container. In gen-
eral, the aerosol mounting cup is fabricated by first stamping a sheet
material through a progressive die to form the mounting cup turret with
a central through aperture and peripheral sealing lip for sealing with
an annular bead disposed on the aerosol container. The stamped
mounting cups are oriented for enabling a solvent based coating and
gasket material to be poured into the lip of the mounting cup. The
solvent based coating and gasket material i6 allowed to set at room
temperature
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for approximately one hour and is the:n progressively passed through
three curing ovens. The three progressive ovens are typically set at
150~C, 250C and 350C. The mounting cup is placed in each oven for
approximately one hour in order to remove ~he solvent totally ~rom the
solvent based coating and gasket material and to leave a solvent residue
of rubber to effect the seal between the mounting cup and the aerosol
container. The heated mounting cups are allowed to cool to proper
handling temperature prior to assembly with the aerosol valve and dip
tube. Presently this prior art process requires approximately four and
one-half hours of time for each mounting cup to provide a suitable
coating for sealing with the aerosol container. However, since the
solvent based coating and gasket material is allowed to flow into the
mounting cup lip, the resultant solid residue of rubber is irregular in
thickness and may result in a defective seal between the mounting cup
and the aerosol container.
Others in the prior art use a precoated process wherein the
mounting cup stock is unrolled and coated with a gasket material. The
sheet stock is punched and formed to create the aerosol valve mounting
cup. Since the sheet stock is coated prior to forming, substantial
stresses are developed within the coating. In addition, the coating may
be damaged during the punching and forming process.
U. S. Patent 3,417,117 illustrates a sealing gasket for an aerosol
mounting cup formed by positioning a circular band of heat-shrinkable
material over a portion of the skirt of the cup. The mounting cup is
then heated to shrink the band of material into frictional contact with
the skirt of the mounting cup.
U. S. Patent 3,443,006 pertains to a method of making a,gasketed
closure element by swelling a band of gasket material and positioning
the band of gasket material about the 9kirt of the mounting cup. The
band of gasket material is then allowed to return to a normal condition
to be in frictional engagement with the mounting cup skirt.
Others in the prior art have utilized electrostatic spraying of
paints on other coatings, but such processes have not been applied to
the application of sealing gaskets.
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Although many in the prior art have attempted various methods to
reduce the time required to apply a gask0t material to an aerosol
mounting cup, the prior art has heretofore failed to provide an inex-
pensive and reliable method which is a suitable replacement to the
solvent based coating and gasket material or the precoated process
which are presently Imiversally used in the aerosol industry.
Therefore, it is an object of this invention to provide an apparatus
which overcomes the aforementioned difficulties of the prior art devices
and provides an improvement which is a significant contribution to the
advancement of the aerosol art.
Another object of this invention is to provide an improved seal
between an aerosol container and a mounting cup incorporating the
deposition of a uniform thickness of plastic sheet material on a sealing
surface to provide a fluid tight seal between the mounting cup and the
aerosol container.
Another object of this invention is to provide an improved seal
between an aerosol container and a mounting cup wherein the time
required to cure the deposited resilient material is substantially less
than the time required to liberate the solvent of a solvent based gasket
material of the prior art.
Another object of this invention is to provide an improved seal
between an aerosol container and a mounting cup wherein a resilient
plastic material is shrink wrapped onto the mounting cup to provide a
umform thickness on the sealing surface.
Another object of this mvention is to provide an improved seal
between an aerosol container and a mounting cup wherein a resilient
material is deposited on the entire internal area of the mounting cup for
providing a fluid tight seal between the mounting cup and the aerosol
container as well as protecting the mounting cup from the substance
internal the aerosol container.
Another object of this in~ention is to provide an improved seal
between an aerosol container and a mounting cup which substantially
reduces the cost of fabrication of aerosol assemblies.
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Another object of this invention is to provide a method of fabri-
cating an aerosol valve and mounting cup through the use of shrink
wrapping an individual mounting cup with a sheet material prior to
receiving the aerosol valve within the mounting cup.
Another object of this invention is to provide a method for apply-
ing a sealing gasket material to a sealing surface between a mounting
cup and an aerosol container incorporating the use of a preheated
plastic material and a vacuum applied to the sealing surface to provide
a sealing gasket for the aerosol container.
The foregoing has outlined some of the more pertinent objects of
the invention. These objects should be construed to be merely illustra-
tive of some of the more prominent features and applications of the
intended invention. Many other beneficial results can be attained by
applying the disclosed invention in a different manner or modifying the
invention within the scope of the disclosure. Accordingly, other ob-
jects and a fuller understanding of the invention may be had by refer-
ring to the summary of the invention and the detailed description
describing the preferred embodiment in addition to the scope of the
invention defined by the claims taken in conjunction with the
accompanying drawings.
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Sl~MMARY OF THE INVENTION
The invention is defined by the appended claims with a specific
embodiment shown in the attached drawings. For the purpose of
summarizing the invention, the invention may be incorporated into an
improved aerosol assembly for an aerosol container having container
sealing means disposed about an upper opening in the aerosol container.
The invention comprise~; a mounting cup having a mounting cup sealing
means extending about the periphery thereof. A valve assembly is
disposed in the mounting cup for providing fluid communication between
the interior of the aerosol container and the exterior of the aerosol con-
tainer. A sealing gasket is included comprising a heat sensitive plastic
material disposed on one of the sealing means for providing a fluid seal
when the mounting cup is secured to the aerosol container.
In a more specific embodiment of the invention, the sealing gasket
is disposed on the mounting cup sealing means. Preferably, the aerosol
container includes a mounting bead disposed on the periphery of an
opening in the aerosol container. The mounting cup includes a lip
disposed about the periphery thereof for cooperation with the mounting
bead of the aerosol container. The sealing gasket may be disposed on
the entire interior surface of the mounting cup for providing a seal
between the mounting cup and the aerosol container and for further
protecting the interior of the mounting cup from the substance internal
the container. The heat sensitive plastic material preferably comprises
a longitudinally extending sheet which is preheated and applied to the
interior surface of the mounting cup by the application of 2 partial
vacuum under the longitudinally extending sheet.
The invention may also be incorporated into the method of fabri-
cating an aerosol valve and mounting cup assembly or the method of
fabricating an aerosol dispensing device. In one embodiment, the
method includes the stamping of a plurality of mounting cups from a
metallic sheet material. The mounting cups are placed on a surface to
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be in a preferred orientation. 'rhe heat sensitive plastic material is
heated to a sufficient temperature to allow the heat sensitive plastic
material to be pliable. The preheated plastic material is placed upon
the mounting cups disposed on the surface and a partial vacuum is
applied to the underside of the preheated plastic sheet material to
secure the plastic sheet material to the mounting cups. The individual
mounting cups are cut from the sheet material and the aerosol valves
are secured thereto in convention manner.
The foregoing has outlined rather broadly the more pertinent and
important features of the present invention in order that the detailed
description of the invention that follows may be better understood so
that the present contribution to the art can be more fully appreciated.
Additional features of the invention will be described hereinafter which
form the subject of the claims of the invention. It should be appre-
ciated by those skilled in the art that the conception and the specific
embodiment disclosed may be readily utilized as a basis for modifying or
designing other structures for carrying out the same purposes of the
present invention. It should also be realized by those skilled in the
art that such equivalent constructions do not depart from the spirit and
scope of the invention as set forth in the appended claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the inven-
tion, reference should be had to the following detailed description taken
in connection with the accompanying drawings in which:
Fig. 1 is a side sectional view of a conventional mounting cup and
aerosol valve assembly;
Fig. 2 is a partial side sectional view showing the fluid tight seal
between a conventional aerosol valve assembly and an aerosol container;
Fig. 3 is a side sectional view of a mounting cup and aerosol valve
assembly in accordance with the present invention;
Fig. 4 illustrates the prior ar~ process for fabricating the mount-
ing cup shown in Fig. l;
Fig. 5 illustrates the improved method of forming the mounting
cups as shown in Fig. 3 in accordance with the present invention;
Figs. 6-8 illustrate various steps in a first process of applying a
preheated plastic material to the mounting cup in accordance with the
present invention; and
Figs. 9-11 illustrate various steps in a second process of applying
a preheated plastic material to the mounting cup in accordance with the
present invention.
Similar reference characters refer to similar parts throughout the
several views of the drawings.
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DETAILED DESC RIPTION
Fig. 1 illustrates a side sectional view of a prior art aerosol
mounting cup and valve assembly 10 which ghould be well known to
those skilled in ~he art. The assembly comprises a mounting cup 12
having a central turret 14 and a mounting lip 16 extending about the
outer periphery thereof . The ~urret 14 receives an aerosol valve
assembly which may be of various designs to operate between an inter-
ior surface 17 and an exterior surface 18. In this embodiment, a valve
body 19 communicates with the interior of the aerosol container through
a dip tube 20. A valve 22 having a valve stem 23 is biased by a
spring 24 into sealing engagement with a sealing gasket 26 for control-
ling the flow of product and propellant through a metering orifice 28
communicating to a valve stem aperture 30.
The mounting lip 16 is provided with a sealing gasket 32 which is
generally a solvent-based rubber material which forms a seal with a
bead 34 of an aerosol container 36 as shown more fully in Fig. 2.
Typically, the mounting cup lip 16 is inserted on the aerosol container
bead 34 with the mounting cup lip being deformed at 38 to form a fluid
tight seal through the coating 32 on the mounting cup lip 16.
Fig. 3 illustrates a mounting cup and aerosol valve assembly 10A
in accordance with the present invention. Under the practice of this
invention the sealing gasket 32A extends along the entire interior
surface 17 of the mounting cup in addition to being applied thereto in
an entirely distinct manner. The sealing gasket material 32A may
optionally be applied to the exterior surface 18 of the mounting cup
tnot shown) as will become apparent hereinafter.
Fig. 4 illustrates the steps in the formation of the mounting cup 12
shown in Fig. 1 under the prior art practice. A ribbon of roll stock 41
disposed on a drum 42 is passed through a series of progressive dies
44 to form the contour of the mounting cup 12 shown in Fig. 1. The
formed mounting cups 12 are passed through an orienter 46 which
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orients the mounting cups 12 such that the interior su~face 17 i5 face
up enabling an applicator 48 to apply a solvent based coating and
gasket material 32 to flow into the mounting cup lip 16. After the
initial coating of gasket material 32, the mounting cups 12 are allowed
to remain at an ambient temperature station 50 for a period of approxi-
mately one hour. The mounting cups 12 are passed through progres-
sive ovens 51, 52 and 53 which respectively have temperatures of
approximately 150C, 250C and 350C. The mounting cups 12 remain
in each of the ovens 51-53 for a period of one hour prior to removing
and cooling in position 54. After cooling, the mounting cups 12 may be
fabricated in a conventional manner as should be well kncwn to those
skilled in the art.
Fig. 5 illustrates the steps in the formation of the mounting cup
12A shown in Fig. 3 under the present invention. A ribbon of roll
stock 41 is disposed on a drum 42 and is through a series of progres-
sive dies 44 to form the contour of the mounting cup 12A shown in Fig.
3. The formed mounting cups 12A are passed through an orienter 46A
which orients the mounting cups 12A on a perforated surface 60 with
the interior surface 17 being disposed face up as shown in Fig. 6. The
perforated surface 60 includes a plurality of conduits 54 communicating
with a vacuum line 66 connected to a vacuum pump (not shown). A
plastic sheet 32A is preheated in a vacuum station 62 and laid over the
interior surfaces 17A of the mounting cups 12A located on the perfor-
ated surface 60 as shown in Fig. 7. A vacuum is drawn on line 66 as
shown by the arrows in Fig. 8 whereby the preheated plastic material
32A is bonded to the mounting cup ~ 2A. The mounting cup 12A is
preferably provided with a lip aperture 70 enabling the vacuum to draw
the sheet material 32A into the interior of the mounting cup lip 16 as
shown in Fig. 8. Since the seal between the aerosol container bead 34
and the mounting cup lip 16 is provided in the region 72, the lip
aperture 70 does not affect the seal therebetween. The sheet material
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2A comprising the plurality of mountiny cups 12 are transferred
to a die cut station 68 wherein the individual mounting cups and
gaskets 32A are severed from the plastic sheet. The die cut
station 68 may also punch an aperture 74 in the sheet material
32A for accommodating the valve stem 23 as shown in Figure 8. The
several mounting cups 12A are received by a conveyor 90 powered
by rollers 92 and 94 for transfer for final assembly including
securing an aerosol valve to each mounting C~lp.
Figures 9 ~ 11 illustrate alternate steps in the
formation of a mounting cup 12A shown in Figure 3 under the
present invention. The mounting cup is ~abricated in a manner
similar to that shown in Figure 5 with the additional steps shown
in Figures 9 - 11. The mounting cups 12A are passed through the
orienter 46A which orients the mounting cups 12A on a perforated
surface 60 having an indentation 61 for locating the mounting
cups thereon. The perforated sur~ace includes a pluarlity of
conduits 64 communicating with the vacuum line 66 connected to a
vacuum pump as was heretofore described. A plastic sheet 32A is
preheated in the vacuum station 62 and is laid over the interior
surface 17A of the mounting cups 12A located on the perforated
surPace 60 as shown in Figure 9. A ~acuum is drawn on line 66 as
shown by the arrows in Figure 10 whereby the preheated plastic
material is drawn into the recesses oP the mounting cup.
Concomitantly therewith,- a die 80 having a die cutter 82 and an
annular protruslon 84 presses the heated plastic material 32A
into intimate contact with the mounting cup as shown in Figure
llo The use of the die 80 punches apeeture 74 in the sheet
material 32 for accommodating the valve stem 23. In addition, the
annular protrusion 84 insures that the sheet material 32~ is
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~onded to the interior of cup lip 12 as shown in Figure 11. The
use of the die 80 may be used independent o~ the lip aperture 70
as shown in Figures 6-8 or may be used in combination therewith,
depending upon the particular application and plastic used.
An aerosol container may be constructed for assembly
with the formed mounting cups and may be filled with product to
be dispensed~ The mounting cup may be secured to the container
and the container may then be pressurized.
Various types of plastic materials may be utilized with
the present invention as should be well known ~o those skilled in
the art. Examples of suitable materials include polyethylene,
accetate, vinyl, polypropylene or other plastic matetials.
Preferably the plastic has a thickness of 0.010 inches to 0.020
inches. It should also be appreciated that the coating provides a
sealing gasket to the lip 16A of the mounting cup in addition to
providing a protective coating to the interior surface 17A of the
mounting cup 12A. The present process reduces the prioe art four
and one-half hours fabrication time for coating a mounting cup to
approximately lO hours. The substantial reduction in time and
expense results in a substantial savinqs of the fabrication cost
of the mounting cup to the aerosol industry. In addition, the
;liberation of undesired solvents over the prior art provides a
reduction of undesired chemicals from the atmosphere which may,
in some cases, produce an undesired environmental impact.
The present disclosure includes that contained in the
appended claims as well as that of the foeegoing description.
` Although this invention has been described in its pteferred form
` with a certain degree of particularity, it is understood that the
present dlsclosure of the preferred form has been made only by
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ay of example and that numerous changes in th~ details of
construction and combination and arrangement of parts may be
resorted to without departing from the spirit and scope of the
invention.
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