U.S. patent number 3,773,064 [Application Number 05/141,268] was granted by the patent office on 1973-11-20 for valve stem sealing ring.
This patent grant is currently assigned to Precision Valve Corporation. Invention is credited to John Richard Focht.
United States Patent |
3,773,064 |
Focht |
November 20, 1973 |
VALVE STEM SEALING RING
Abstract
A sealing system for pressurized container valves particularly
designed for the dispensing of solid products in powdered form
including means for preventing the disabling buildup of the product
residue on the sealing surfaces.
Inventors: |
Focht; John Richard (Yonkers,
NY) |
Assignee: |
Precision Valve Corporation
(Yonkers, NY)
|
Family
ID: |
22494934 |
Appl.
No.: |
05/141,268 |
Filed: |
May 7, 1971 |
Current U.S.
Class: |
137/244;
222/402.24; 251/333 |
Current CPC
Class: |
B65D
83/48 (20130101); Y10T 137/4336 (20150401) |
Current International
Class: |
B65D
83/14 (20060101); F16k 001/30 () |
Field of
Search: |
;222/148,402.24,402.1,402.22,518 ;239/114,123,541,573,579
;137/242,244 ;251/353,333 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schwadron; Martin P.
Assistant Examiner: Gerard; Richard
Claims
I claim:
1. A dispensing valve for a pressurized aerosol container
comprising:
a valve housing,
a valve body movable axially with respect to the housing between
closed and open positions, the valve body having a discharge
passage communicating with the exterior of the container, and a
valve orifice extending radially into communication with said
discharge passage,
an annular resilient sealing gasket having a central aperture
defined by a sealing surface encompassing and sealing said valve
orifice when the valve body is in the closed position,
means to bias the valve body toward the closed position, and
an annular ridge means encircling said valve body located
interiorly of the container from the valve orifice on a portion of
the valve body encompassed and sealed by the resilient sealing
means when the valve body is in the closed position with said ridge
means engaging the sealing surface of said annular gasket.
2. The valve as described in claim 1, wherein the valve body
includes an upstanding hollow stem portion including said discharge
passage, a cylindrical portion of smaller diameter than the stem
portion, and an interposed conical portion tapering from the stem
portion to the cylindrical portion, the radial valve orifice being
located in said conical portion and the ridge means being located
on said cylindrical portion.
3. The valve as described in claim 2, wherein the ridge means
comprises at least one circumferential projection on the valve body
in a plane substantially prependicular to the axis of the valve
body.
4. The valve as described in claim 3, wherein the cross section of
the projection is a shape having a sharp apex.
Description
BACKGROUND OF THE INVENTION
Aerosol dispensers commonly contain a supply of the product to be
dispensed together with a quantity of propellant in liquid form,
all held within a pressurized container. The valves in such devices
are actuated by a movement of the valve body with respect to the
pressurized container which movement uncovers an orifice completing
a path from the container to a discharge nozzle. The product to be
dispensed and the propellant are forced along the path by the
pressure of the propellant within the container.
Because of their mutual solubility, liquid products tend to remain
well mixed with the propellant during movement along the path.
However, insoluble portions of some products and portions of
particulate or powdered products tend to fall from the flowing
stream of product and propellant and may accumulate at places along
the path. This accumulation of undispensed product can cause
disabling of the dispenser by clogging the orifice so that further
discharge is diminished or by lodging on the sealing surfaces,
preventing complete and proper sealing of the valve so that the
propellant gas seeps out uncontrollably, prematurely exhausting the
propellant supply. One proposed solution to the latter problem,
applicable to aerosol valves of the type wherein sealing is
accomplished by the abutting of a portion of the valve body against
the underside of the sealing gasket, is proposed in British Patent
No. 1,216,655. An apparently similar valve appears in Aerosol Age,
Jan. 1, 1969, at page 24. It involves the use of three annular ribs
concentric with each other and with the central axis of the valve
and arranged to press upward against the bottom of the sealing
gasket when the valve is in its closed position to establish a
seal. During closure, accumulated particles of solid product are
deflected laterally to occupy the grooves between the ribs, and
since sealing is accomplished between the points of the ribs and
the gasket, it is not at first affected by the presence of such
particles. However, as more and more particles accumulate in the
grooves, their net bulk may begin to adversely affect the
effectiveness of the seal. The present invention provides a way of
preventing seepage from pressurized aerosol containers which is
less subject to loss of effectivness by product accumulation.
SUMMARY OF THE INVENTION
The present invention is particularly applicable to aerosol valves
of the type wherein valve sealing is accomplished primarily by
radial force exerted on the valve body by its encircling gasket. In
previous constructions of this valve type, the valve body typically
includes a narrow cylindrical section including the valve orifice
and encircled by the gasket. A conical tapered section above the
cylindrical section is topped by an upstanding valve stem. The
orifice in the narrow cylindrical section communicates with a
hollow interior passage in the valve body leading to the discharge
orifice. The narrow cylindrical section and at least a portion of
the conical tapered section are encircled by the aperture of an
annular resilient gasket when the valve is closed, but when the
valve body is depressed, the conical tapered section causes the
inner aperture or sealing surface of the gasket to peel away from
the valve body, thereby opening the dispensing path through the
orifice.
According to the present invention a protruding annular ridge is
provided about the narrow cylindrical section of the previously
described valve body, and the valve orifice is located in a
position above this ridge, in the upper region of the cylindrical
section or in the conical tapered section of the valve body. The
protruding ridge presses into the resilient gasket, providing a
labyrinthine sealing contour less likely to leak than previous
constructions. In addition, depression of the valve body for valve
actuation results in some relative motion of the valve body with
respect to the sealing surface of the gasket which moves the ridge
with respect to the sealing gasket. This tends to dislodge
accumulations of undispensed solid product. Further, during
closure, flow is terminated before the gasket is restored to its
radially compressed engagement with the valve body thereby
providing an opportunity for disentrained particulate matter in the
sealing region to fall away from that region.
DRAWINGS
FIG. 1 is an elevational view in partial section showing the valve
of the present invention in the closed position, and
FIG. 2 is an elevational view in partial section showing the same
valve during actuation, with the valve orifice shown rotated
laterally 90.degree. from its position in FIG. 1.
DETAILED DESCRIPTION
Those Figures show a valve assembly 10 fitted and crimped into a
pedestal portion 11 of a mounting cup closure for a pressurized
dispenser, not shown. Valve assembly 10 includes dip tube 12, dip
tube receiving nipple 13, valve housing 14, coil spring 15, and
valve body 16. A resilient annular gasket 17 encircles a section of
valve body 16. Valve body 16 includes an upstanding hollow valve
stem 19, below that a conical tapered section 20 containing an
orifice 21, then a narrowed cylindrical section 22 having an
encircling protruding annular ridge 23, and finally a lower portion
24 adapted to receive a coil spring 15. Shoulder 25 is formed by
the intersection of the narrow portion 22 and the lower portion 24
of valve body 16. When the valve is in its closed position, shown
in FIG. 1, shoulder 25 abuts against the underside of gasket 17
under the urging of spring 15 to provide a sealing surface and the
inner edge of gasket 17 presses tightly against the surfaces of
valve body 16, including those of its encircling ridge 23, to
provide the primary seal.
The valve is actuated by applying sufficient downward force on
valve stem 19 to overcome the upward bias of spring 15. As valve
body 16 moves down, tapered section 20 deflects downward the inner
edge of gasket 17, causing it to peel away from orifice 21 and
eventually expose the orifice 21 to the pressurized product within
the container. During the initial phase of the opening operation,
shoulder 25 will leave contact with the underside of gasket 17 and
the inner edge of gasket 17 will be partially peeled away from
valve body 16.
It will be apparent that the bottom of the inner edge peels away
from the valve body first. Because, in the present invention,
orifice 21 is located at a higher position on the valve body than
in most valves of this type, the stroke required to depress the
inner edge of gasket 17 enough to expose orifice 21 to the
pressurized interior of the container is somewhat longer than is
otherwise required. The significance of this longer stroke will
become apparent from the following discussion.
During the opening operation valve body 16 simply moves downward,
while points on the inner sealing surface of gasket 17 move both
downward and radially away from the valve body and also undergo
some compression. This deflection of the gasket results in motion
of the inner sealing surface of the gasket with respect to the
valve body 16 and its integral ridge 23. In other words, a given
point on the gasket sealing surface moves downward a smaller
distance during the opening operation than the adjacent point on
valve body 16. Therefore, as ridge 23 moves downward, there will be
relative vertical movement between the ridge and the surrounding
inner sealing surface of gasket 17. This relative motion tends to
dislodge product residues present on the valve body or the gasket
sealing surfaces. If the product residue is in the form of
agglomerations or clots, the ridge 23 will tend to pulverize the
clots upon closure motion and tend to dislodge the clots from the
sealing surface.
Furthermore, because the orifice 21 is not significantly unsealed
until the valve body 16 has nearly completed its downward movement,
particulate matter which has been dislodged by the interaction of
the ridge and the inner gasket edge is free to fall back into the
container. Thus the longer stroke required prior to opening and
subsequent to terminating product flow on closing ensures that the
dislodged material will have an opportunity to fall away and will
not be swept up to other sealing surfaces or to the valve
orifice.
While many ridge cross-sections are feasible for the practicing of
the present invention, it has been found particularly efficacious
to use a triangular ridge having a base thickness of 0.0034 inches
and a height of 0.003 inches, mounted on a narrowed cylindrical
portion (corresponding to portion 22) approximately 0.125 inches in
diameter.
* * * * *