SPRAYER TANK CAP WITH INCORPORATED PRESSURE RELIEF VALVE

COUVERCLE DE RESERVOIR DE PULVERISATEUR AVEC SOUPAPE DE SURPRESSION INCORPOREE

English Abstract

A cap for closing a sprayer tank has integrated therein a pressure relief valve having a tubular member providing a seat with respect to which a valve provided by an o-ring on a stem is displaced in a direction against the seat to close the valve. The stem is connected at one end thereof to a cap and is biased by a spring around the stem at the opposite end thereof into closing position. The cap is guided by a rim around the seat member. The cap defines around the stem a chamber. This chamber communicates with a spout which directs pressurized flow away from the cap when it is rotated to manually open the valve against the bias of the spring so as to relieve pressure in the tank. The passageway provided by the spout and the chamber is much larger than the passageway around the rim of the cap so that substantially all of the pressurized flow is diverted by this snout away from the fingers of the person grasping the cap at ears providing wings on the cap for rotating the cap to displace the valve to open position.

French Abstract

Un couvercle pour fermer un réservoir de pulvérisateur intègre un détendeur de pression qui possède un élément tubulaire faisant office de siège pour une soupape formée d'un joint torique sur tige, cette soupape se déplaçant en opposition au siège, de manière fermer la soupape. La tige est connectée à l'une de ses extrémités à un couvercle et est positionnée préférentiellement par un ressort autour de la tige à l'extrémité opposée, dans une position fermée. Le couvercle est guidé par une jante autour du siège. Le couvercle définit une chambre autour de la tige. Cette chambre communique avec un embout qui dirige le flux pressurisé dans la direction opposée au couvercle lorsqu'on le tourne pour ouvrir manuellement la soupape, contre la force appliquée par le ressort, afin de détendre la pression dans le réservoir. La voie créée par l'embout et la chambre est bien plus grande que la voie autour de la jante du couvercle de sorte que l'embout dévie la majeure partie du flux loin des doigts d'une personne manipulant le couvercle muni d'oreilles pour le faire tourner et mettre la soupape en position ouverte.

Claims

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CLAIMS:
1. A pressure relief valve (PRV) for relieving pressure in a tank, both
upon over
pressure conditions in the tank and when manually actuated, said PRV
comprising a valve
stem displaceable with respect to a valve seat for containing pressure in said
tank when the
valve stem is closed against said valve seat and for relieving pressure in
said tank via a path
through said valve stem providing a passageway for pressurized flow when said
valve stem is
displaced from a closed to an open position, said PRV also comprising a valve
cap mounted
on said seat and attached to said valve stem, said valve cap having a spout
and a chamber
communicating with said passageway, the passageway for pressurized flow
comprises a
serpentine annular area in the vicinity of the valve cap and an opening in the
spout, wherein
the serpentine annular area is of smaller size than the chamber and the
opening in the spout,
whereby substantially all of the pressurized flow is diverted out of the
opening in the spout.
2. The valve according to Claim 1 further comprising a tank closing cap
which
closes the tank, and wherein said valve seat is integrated into a said tank
closing cap.
3. The valve according to Claim 1 further comprising a tank closing cover
which
closes the tank, and wherein said valve seat is provided by a tubular member
integral with
said tank closing cover and extending in opposite directions to provide an end
outside of said
tank and an end extending into said tank when said tank closing cover closes
said tank.
4. The valve according to Claim 1 wherein said valve seat is in a tubular
member,
said valve stem having a stem connected to said valve cap, said stem and said
valve cap being
biased in a direction to close said valve stem, said chamber being defined by
said valve cap
around said stem, said chamber communicating with said spout.
5. The valve according to Claim 4 wherein said valve cap is rotatable to
displace
said valve stem in oppposite directions from closed to opened positions.

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6. The valve according to Claim 5 further comprising a spring on said valve
stem
biasing said valve stem in the closing direction, and ramp surfaces in said
seat on which said
valve cap rides for rotation in a closing direction under the bias of said
spring and in the
opening direction when said valve cap is manually rotated.
7. The valve according to Claim 6 further comprising ears providing wings
on
said valve cap by which said valve cap can be manually grasped and rotated in
the opening
direction.
8. The valve according to Claim 1 wherein said opening and chamber of said
spout is of a size that presents a lower resistance to said pressurized flow
than any other
opening along said passageway to enable passage of substantially all of said
pressurized flow
out of said spout when said pressurized flow is present in said passageway.
9. An apparatus for relieving pressure in a tank, both upon over pressure
conditions in the tank and when manually actuated comprising:
means for relieving contained pressure in said tank via a path providing a
passageway
for pressurized flow from said tank;
said pressure relieving (PR) apparatus (PRA) having a cap; and
means in said PRA cap in communication with said passageway for passage of
said
pressurized flow from said tank away from said PRA cap when said pressurized
flow is
present in said passageway, wherein said means in said PRA cap provides a
serpentine
annular area that presents a lower resistance to said pressurized flow than
any other opening
along said passageway to enable passage of substantially all of said
pressurized flow through
said means in said PRA cap away from said PRA cap.
10. The apparauts according to Claim 9 wherein said means for relieving is
positionable between a first position to contain said pressure and a second
position to relieve
said pressure along said path.

Description

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SPRAYER TANK CAP WITH INCORPORATED PRESSURE RELIEF VALVE
Description
The present invention relates to pressure relief valves and provides
facilities for
manually opening the valve to relieve and reduce pressure in a tank without
exposing the
person actuating the valve to relieve the pressure to vapor or other
pressurized flow out of
the tank. Tanks with which the pressure relief valve may be used may be
sprayer tanks
which contain materials, such as insecticides and herbicides, that may be
toxic and
exposure to which is undesirable. The invention also provides a cap for a
tank, such as a
sprayer tank, in which the pressure relief valve may be integrated.
Reference may be had to U.S. Design Patent No. 391,626, issued March 3, 1998
to Clark F. Spriegel; U.S. Patent No. 7,025,878, issued April 11, 2006, also
to Clark F.
Spriegel; and U.S. Patent No. 6,695,228, issued to Ronald M. Odessa, on
February 24,
2004, for further information with respect to sprayer tanks with which the cap
provided
by the invention may be used, which patents may be deemed by this reference to
be
incorporated herein and made part hereof.
Sprayer tanks are maintained under pressure so as to enable the pressurized
flow
of the material in the tank through a hose or wand and out of a nozzle. When
the tank is
under pressure, as when the tank is partially full, it may be desirable to
open the tank by
loosening and removing the cap thereon, so as to extract or add material to be
sprayed to
the tank. In such cases, the pressure in the tank makes it difficult to open
the cap.
Moreover, opening the cap on the tank may release the material in the tank in
a vapor or
spray which is undesirable, particularly since the material may be toxic.
Under such
circumstances, it is desirable to use the pressure relief valve with which the
tank is
equipped, as by being installed in a pipe stem extending from the tank near
the top
thereof. The valve is opened much like it would be opened in an over pressure
condition,
but rather than by the over pressure in the tank, by manually pulling up on
the stem of the
pressure relief valve. This stem may be connected to a cover or cap. Then,
when the cap
is actuated by being pulled up so as to open the pressure relief valve,
pressurized flow of

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possibly toxic material may emanate from around the rim of the cap, which is
connected
to the stem while the cap is grasped by the fingers of the operator to pull
and hold the
stem upwardly to open the valve.
It is a feature of the present invention to facilitate avoiding exposure to
vapor or
other pressurized flow of material in the tank when the pressure relief valve
is manually
actuated to open position, thereby reducing contamination by virtue of such
exposure, as
by toxic material released via the pressure relief valve.
Briefly described, the invention enables flow of the pressurized material,
such as
pressurized vapor from the tank by diverting the flow away from the cap of the
pressure
relief valve. Such diversion is accomplished by providing a spout on the valve
having an
opening which communicates with the valve, such spout being long enough to
divert the
pressurized flow of vapor or fluid away from the cap. The diversion of
substantially all
of the pressurized fluid or vapor is obtained by sizing the opening in the
spout so that it is
sufficiently greater than any other openings which are communicating with the
passageway from the valve. The spout presents a much lower resistance to the
flow
enabling substantially all of the pressurized flow to be diverted out of the
snout. The cap
may be mounted to rotate on a rim around the seat. The opening provided by the
spout is
much larger than the opening presented between the rim and the seat.
Accordingly, even
when the valve is open, substantially all of the pressurized flow is diverted
out of the
snout and away from the fingers of the operator who opens the pressure relief
valve as by
rotating the cap. The valve seat may be a tubular member which is integrated
with the.
closing cap, such as by being molded in or as a part of the tank closing cap,
thereby
providing a manually actuatable as well as automatically, spring operated
pressure release
valve mechanism.
The foregoing and other objects, features and advantages of the invention, as
well
as a presently preferred embodiment thereof, will become more apparent from a
reading
of the following description in connection with the accompanying drawings in
which:
FIG. I is a perspective view from the top of a tank closing cap with
incorporated
pressure relief valve in accordance with the invention;

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FIG. 2 is a broken-away, sectional view of the closing cap shown in FIG. 3
with
the pressure relief valve in closed position, the view being taken along the
line 2-2 in
FIG. 1 in the direction of the arrows;
FIG. 3 is a view similar to FIG. 2 but with the pressure relief valve manually
actuated by being rotated approximately 180 from the position thereof when
the valve is
closed, as shown in FIG. 2, and showing how the pressurized flow of liquid or
vapor is
diverted away from the cap of the pressure relief valve while it is rotated
and also while it
is held, upon actuation, to relieve the pressure in the tank;
FIG. 4 is an exploded view of the pressure relief valve shown in the previous
figures, the valve seat being shown as a tubular member_instead of being
integrated in the
tank closing cap as shown in FIGS. 1-3. It will be appreciated that the valve
seat may be
threaded for insertion in a pipe stem extending from a tank, rather than being
integrated
into the tank closing cap; and
FIG. 5 is a section through the exploded view of FIG. 4 which is taken
generally
along the line 5-5 in FIG. 4.
Referring more particularly to the drawings, there is shown a sprayer tank-
closing
cap 10. A pressure relief valve 12 is integrated with the cap as by having a
tubular
member 14 which defines the valve seat 16 of the valve 12 molded integrally
with the cap
10.
The cap 10 has a screw on connection 18 to the sprayer tank as well as a
decorative skirt 20. The cap 10 has an opening 22 in which the sprayer tank
handle and
its mechanism for pumping and pressurizing the tank may be disposed. Further
information as to the sprayer tank, the handle and its mechanism may be found
by
reference to the above entitled patents. The tank may be of the type which is
used in
sprayers called "Spray-n-Go" which are manufactured and sold by Chapin
Manufacturing, Inc. of Batavia, New York.
The cap region 24 around the opening 22 may be provided with radial and
laterally disposed struts 26 and 28 on the top and bottom thereof,
respectively. The struts
26 decoratively provide strengthening for the tank closing cap 10.
As shown in FIGS. 2 and 3 and also in FIGS. 4 and 5, the pressure relief valve
12
is tubular member 14, which provides the valve seat 16, has champhered or
tapered inner

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periphery 32 on an inner periphery thereof. The valve is provided by a valve
stem 34
having a flange 36 which captures an o-ring 38 and compresses the ring against
the
tapered inner periphery 32 to close the valve.
The stem 34 is surrounded at the lower end thereof by a compression spring 40,
one end of which bears against a disc like surface 42 at the bottom of a
collar 44 of the
tubular member 14 providing the valve seat 16. A snap on washer 46 on the
lower end of
the stem 34 provides a bearing surface for the lower end of the spring 40. The
spring 40
therefore biases the stem 34 and the ring 38 downwardly against the champhered
periphery seat, closing the valve 16 unless and until an overpressure
condition in the tank
(principally applied to the lower end face of the stem 34} exceeds the biasing
force and
enables the pressure relief valve to open and relieve the pressure. In
addition, the
pressure relief valve has facilities for being manually actuated and displaced
to an open
position.
Manual displacement is provided by a cap 50 having a rim 52, which rides on a
collar 54, at the upper end of the tubular member 14 providing the valve seat
16.
This cap 50 also is disposed as a sleeve around the valve stem 34 and defines
a
chamber 58 around the upper end of the stem 34. The stem 34 has a recessed,
tapered
button 68 at the upper end thereof which snaps into the top of the cap 50,
connecting the
cap 50 to stem 34. The tubular member 14 providing the valve seat 16 has along
the
upper end thereof, ramps 62 which are engaged by ramp following fingers 64,
which are
part of the cap 50 and extend downwardly from the top thereof to engage the
ramps.
These ramps and fingers cause the cap 50 to rotate, either when displaced
downwardly by the biasing force of the spring 40 to valve closing position as
shown in
FIG. 2 or upwardly to valve opening position as shown in FIG. 3. The cap 50 is
provided
with two features, one of which is the flow diverting snout 70 having an
opening 72
communicating with the chamber 58. Also, the cap is provided with ears 74,
which act as
wings to enable the cap to be rotated manually for actuating the valve to open
position.
When the valve cap is rotated, the fingers 64 and ramps 62 displace the cap
upwardly in a direction along the axis of the stem 34. As shown in FIG. 3,
pressurized
flow of vapor or liquid from the tank is, in the direction of the arrows,
through a passage
in the tubular member providing the seat 16 around the stem, past the valve
16, and into

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the chai'nber 58. Flow is then through the diverting spout 70 and away from
the hand and
fingers of the user who rotates the cap and holds it to enable the venting of
the tank
through the pressure relief valve 12. The passageway around the stem 34, which
may
have a serpentine annular area 75 around the collar 52 and rim 54. The
passageway in
the vicinity of the cap 50 at the area 75 is of much smaller size than the
passageway
through the chamber 58 and the opening 72 in the spout 70. Exiting of vapor or
liquid
via the serpentine annular area 75 is reduced and substantially eliminated by
virtue of the
configuration and sizing of the spout opening 72 and chamber 58 relative to
the area 75
into the vicinity of the cap is of much smaller size than the passageway
through the
chamber 58 and the opening 72 in the spout 70. Therefore, substantially all of
the
pressurized flow is out of the spout 70 and is diverted away from the person
actuating the
pressure relief valve, thereby avoiding exposure with the pressurized flow and
the
possible toxic materials therein.
Accordingly, there has been provided an improved pressure relief valve, and
especially a spray tank cap or cover with which the pressure relief valve is
integrated.
Variations and modifications in the herein described apparatus, within the
scope of the
invention, will undoubtedly suggest themselves to those skilled in the art.
Accordingly,
the foregoing description should be taken as illustrative, and not in a
limiting sense.

Representative Drawing