U.S. patent number 3,815,794 [Application Number 05/231,288] was granted by the patent office on 1974-06-11 for plastic-film containers with self-sealing orifices.
Invention is credited to Richard S. Carlisle.
United States Patent |
3,815,794 |
Carlisle |
June 11, 1974 |
PLASTIC-FILM CONTAINERS WITH SELF-SEALING ORIFICES
Abstract
The disclosed containers are formed of supple plastic films
fused together face-to-face along continuous seams that converge in
the fluid-discharge direction to form a spout. When part of the
spout is distended by fluid contents, a seal forms between the
films. Squeezing the container develops internal fluid pressure
that causes release of the seal. Depending on the proportions of
the spout, the seal is either self-restoring when pressure is
relaxed, or the seal remains open until it is manually restored.
The form of the spout also determines the character of the
discharge, whether a continuing stream, or a limited-quantity
discharge, or a fine jet that breaks up into a spray. Adding a
spout-pressing plate to a container having a self-restoring seal
forms a novel dispenser. A guard applied to the spout can prevent
unintended opening of the seal when the container is squeezed. The
films that form the container can be shaped to provide a stable
gusseted base. In a variant, a container has a spout proportioned
to form an especially secure seal across the discharge passage,
which does not open in response to practical levels of internal
pressure. Such a seal is rendered pressure-releasable, and it can
even be released entirely, by lessening the distension of the spout
walls. Both in this variant and where the seal is
pressure-releasable, internal fluid pressure builds up when the
container is squeezed in use or in handling. With both types of
seal, the danger of developing wall-bursting stresses due to
internal pressure is minimized by shaping all seams so as to be
free of corners directed toward the interior of the container.
Inventors: |
Carlisle; Richard S.
(Thornwood, NY) |
Family
ID: |
22868574 |
Appl.
No.: |
05/231,288 |
Filed: |
March 2, 1972 |
Current U.S.
Class: |
222/491; 222/530;
383/44; 222/107; 383/43; 383/49 |
Current CPC
Class: |
B65D
75/5822 (20130101); B65D 2575/586 (20130101) |
Current International
Class: |
B29C
65/00 (20060101); B29C 65/18 (20060101); B29C
65/02 (20060101); B29C 65/78 (20060101); B29C
65/24 (20060101); B29C 65/74 (20060101); B65D
75/52 (20060101); B65D 75/58 (20060101); B65d
037/00 () |
Field of
Search: |
;222/491,494,173,105,107,527-530 ;248/97,108,109,152,346,350
;150/50,9,51 ;229/57,62,62.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tollberg; Stanley H.
Claims
What is claimed is:
1. A container for fluids having a body and a spout extending
outwardly from the body, said spout having congruent opposing walls
of supple, imperforate material and being defined by laterally
spaced seams uniting said walls and disposing them in substantially
face-to-face contact when said spout is empty, said seams including
first seam elements extending divergently at least from an
intermediate portion of the spout generally toward said body, said
container being dimensioned and configured to provide means for
forming a releasable seal across said spout at said intermediate
portion thereof, opposing first sections of said walls between said
first seam elements being free of interconnection and being adapted
to become readily distended by contained fluid, such distension
causing said first wall sections to converge into sealing abutment
with one another with the centerlines of said first wall sections
adjacent said abutment forming an angle of less than about
90.degree. and with opposing second sections of said walls
conextending from said abutment with the centerlines thereof in
general alignment with the centerline of one of said first wall
sections and at an angle to the centerline of the other of said
first wall sections, whereby said spout can be sealed without
auxiliary sealing means.
2. The container in accordance with claim 1, wherein said walls of
the spout have a limited degree of elasticity so that portions of
said coextending second wall sections at and near said abutment are
warped relative to an imaginary curved but unwarped surface
extending between said laterally spaced seams, thereby tending to
reinforce said sealing abutment.
3. The container of claim 1, wherein said seams and walls of said
spout are dimensioned and configured so that the relationship of
said second wall sections to said first wall sections is altered
when a substantial level of internal fluid pressure is developed so
as to overcome said sealing abutment, thereby permitting fluid
contents to discharge from said container.
4. The container of claim 3 wherein said container is dimensioned
and configured so that said walls tend to restore said sealing
abutment upon diminution of the internal pressure from said
substantial level thereof, thereby tending to automatically reclose
said container upon such pressure diminution.
5. The container of claim 3 wherein said container is are
dimensioned and configured so that the altered relationship between
said first and second wall sections is stable so that said sealing
abutment is restorable to reclose said container only upon the
application of external force to said spout.
6. The container of claim 1 wherein said seams include second
elements defining said second wall sections, said second seam
elements extending generally divergently toward said body, the
divergence thereof being less pronounced than that of said first
elements to define a generally outwardly tapering flow passage
through said spout.
7. The container of claim 6 wherein said seams defining said spout
are of smoothly curvilinear configuration.
8. The container of claim 7 wherein said curvilinear seams are
relatively narrow and are located substantially at the lateral
edges of said spout.
9. The container of claim 1 wherein when the container is flat,
segments of said seams converge toward an imaginary point located
within a region of said container outward of said intermediate
portion of the spout.
10. The container of claim 7 wherein said container is dimensioned
and configured so that said abutment is progressively shifted along
said outwardly tapering flow passage and away from said body at
progressively increasing levels of internal pressure, ultimately
overcoming the sealing abutment and permitting fluid contents to
discharge from said container.
11. A container having congruent opposing walls of supple,
imperforate material having at least one bond uniting said walls
and disposing them in face-to-face contact when said container is
empty, said opposing congruent walls providing integral walls of a
body for containing fluids and of a spout projecting outwardly from
said body, said spout being defined by laterally spaced seams
provided by said bond and including seam portions extending
divergently at least from an intermediate portion of the spout
generally toward said body, said container being dimensioned and
configured to provide means for forming a releasable seal across
the spout at said intermediate portion thereof, opposing first wall
sections between said divergently extending seam portions being
free of interconnection and being adapted to become readily
distended by contained fluid, such distension causing said first
opposing wall sections to converge into sealing abutment with one
another with the centerlines of said first wall sections adjacent
said abutment forming an angle of less than about 90.degree. and
with opposing second sections of said walls coextending from said
abutment with their centerlines in general alignment with the
centerline of one of said first wall sections and at an angle to
the centerline of the other of said first wall sections, whereby
said spout can be sealed without auxiliary sealing means.
12. The container of claim 11 wherein said layers are comprised of
synthetic resinous thermoplastic material.
13. The container of claim 12 wherein said bond is a relatively
narrow heat seal located substantially at the edge of said
container.
14. The container of claim 13 wherein said body is of generally
circular configuration and said discharge region is an elongated,
outwardly tapering extension thereof, said container thereby being
of generally tear-drop configuration.
15. The container of claim 11 wherein said body has, in a flat
disposition, a generally rectilinear edge extending thereacross at
a location remote from said spout, said edge being of a length that
is substantially less than the width of said walls of said body at
a location spaced a short distance therefrom, intermediate portions
of said body walls lying between said edge and said spaced location
being narrower than said body walls at said location so that, when
said container is placed in an upright position with said edge
disposed thereunder on a support surface, the outer margins of said
intermediate wall portions tend to fold inwardly of said body, in
turn permitting distension of said wall portions therebetween under
the weight of fluid contents, thereby providing an extended base
area for supporting said container in a relatively stable, upright
position.
16. The container of claim 15 wherein said intermediate wall
portions are defined by generally rectilinear slanting seam
portions extending outwardly from the ends of said rectilinear
edge.
17. The container of claim 1 wherein said container additionally
includes fluid contents therewithin, and is completely closed to
provide an integral package.
18. A container for fluids having a body and a spout extending
outwardly from the body, said spout having congruent opposing walls
of supple, imperforate material and being defined by laterally
spaced seams uniting said walls and disposing them in substantially
face-to-face contact when said spout is empty, said seams including
first seam elements extending divergently at least from an
intermediate portion of the spout generally toward said body, said
container being dimensioned and configured to provide means for
forming a releasable seal across said spout at said intermediate
portion thereof, opposing first sections of said walls between said
first seam elements being free of interconnection and being adapted
to become readily distended by contained fluid, such distension
causing said first wall sections to converge into sealing abutment
with one another with the centerlines of said first wall sections
adjacent said abutment forming an angle of less than about
90.degree. and with opposing second sections of said walls
coextending from said abutment with the centerlines thereof in
general alignment with the centerline of one of said first wall
sections and at an angle to the centerline of the other of said
first wall sections, whereby said spout can be sealed without
auxiliary sealing means, that portion of the container which
comprises said spout and the portion of said body which adjoins the
spout being free of inwardly directed corners having a tendency to
move inwardly a substantial distance, which would result in
increasing the angle of convergence of said first wall sections and
in reinforcing said sealing abutment in response to development of
substantial internal pressures.
19. A container for liquids having a body and a spout extending
outwardly from the body, said spout having congruent opposing walls
of supple imperforate material defined by laterally spaced seams
uniting said walls and disposing them in substantially face-to-face
contact when said spout is empty, said walls including first
opposing wall sections adjoining said body and bounded by first
elements of said seams, said first wall sections being adapted to
become readily distended by liquid in the container in the absence
of applied pressure and specifically being free of interconnection
between said seam elements, and said walls including second
opposing wall sections projecting from said first opposing wall
sections, segments of said first elements of said seams converging
toward a point in said spout outward of said first wall sections
when the container is flat, said container being dimensioned and
configured to provide means for forming a generally arcuate
internal-pressure-releasable and self-restorable seal across said
spout at a portion thereof where said second wall sections extend
from first wall sections, said first wall sections when distended
converging into sealing abutment with one another in the absence of
seal-releasing pressure, with the centerlines of said first wall
sections adjacent said abutment forming an angle of less than about
90.degree. and with opposing second sections of said walls
coextending from said abutment with the centerlines thereof in
general alignment with the centerline of one of said first wall
sections and at an angle to the centerline of the other of said
first wall sections, whereby said spout can be sealed without
resort to auxiliary sealing means.
20. A squeeze-releasable dispensing container including a main body
and a spout projecting outwardly therefrom, the spout and the
adjoining portion of the body providing a discharge region, said
container having congruent supple, imperforate walls, said walls
being united along seams that tend to dispose the walls
substantially face-to-face when the container is empty, said seams
including seam portions bounding first wall sections of the spout
adjoining the body which seam portions converge toward each other
along the spout in the fluid-discharge direction, the walls of the
discharge region being adapted to become readily distended by
contained fluid and specifically being free of interconnection
between said seams, and said container being dimensioned and
configured to provide means for forming an
internal-pressure-releasable seal across the spout wherein one of
the walls when distended by contained fluid bears against the other
in a sealing abutment extending generally arcuately between said
seams with the centerlines of said first wall sections adjacent
said abutment forming an angle of less than about 90.degree. and
with opposing second sections of said walls coextending from said
abutment with the centerlines thereof in general alignment with the
centerline of one of said first wall sections and at an angle to
the centerline of the other of said first wall sections, whereby
said spout can be sealed without auxiliary sealing means.
21. A container for fluids, including a body and a spout projecting
outwardly therefrom, the spout and the adjoining portion of the
body providing a discharge region, said discharge region being
formed of congruent opposing walls of supple imperforate material
interconnected by seams disposing the walls substantially
face-to-face when the discharge region is empty, a first portion of
the spout adjoining the body being defined by elements of said
seams, such interconnection between said walls being shaped for
causing said first spout portion to become readily distended by
contained fluid, said discharge region being dimensioned and
configured to provide means for causing said first spout portion to
decrease in cross-section progressively in the fluid discharge
direction when distended by contained fluid and, when so distended,
for forming a sealing abutment extending generally arcuately across
said spout wherein one of said walls bears against the other with
the centerlines of said first wall sections adjacent said abutment
forming an angle of less than about 90.degree. and with opposing
second sections of said walls coextending from said abutment with
the centerlines thereof in general alignment with the centerline of
one of said first wall sections and at an angle to the centerline
of the other of said first wall sections, whereby said spout can be
sealed without auxiliary sealing means.
22. A container in accordance with claim 1 wherein the divergence
of at least segments of said first elements of said seams adjacent
said abutment is limited to result in a reduction of the angle of
divergence of said segments when said first wall sections become
distended by fluid.
23. A container in accordance with claim 1 wherein the portions of
said seams between said body and said intermediate portion of the
spout have a curvature having a minimum radius of at least one-half
inch when the container is flat.
24. A container in accordance with claim 11 wherein said container
is dimensioned and configured to render said releasable seal
responsive to internal fluid pressure, said container additionally
including a second self-sealing spout non-releasable in response to
internal fluid pressure sufficient to release said releasable
seal.
25. In combination, the container in accordance with claim 19 and
means for suspending said container with said spout directed
downward, further including a pair of pressure-applying devices
disposed at opposite sides of said container above said seal,
whereby abrupt actuation of said pressure-applying devices causes
said container to dispense a discrete quantity of liquid.
26. A container in accordance with claim 19 wherein the width of
the outer extremity of said spout is limited to cause discharged
liquid to form a spiral jet which breaks up into droplets.
27. The container of claim 12 wherein each of said walls comprises
a laminate containing at least two distinct materials.
28. The container of claim 17 wherein said spout has a fused
closure adjacent its outer end which is removable to provide a
discharge opening.
29. The container of claim 17 wherein said second wall sections
have a discharge opening adjacent the outer ends thereof, and
wherein said container additionally includes a closure member
disengagedly secured on said second wall sections to temporarily
close said discharge opening.
Description
The present invention relates to containers having plastic-film
walls and a discharge passage for fluids, especially for dispensing
liquids.
Containers having plastic-film walls and a discharge orifice are
usually equipped with some form of plug or discrete valve structure
such as a pinch clamp for closing the orifice when the contents are
to be used a little at a time. On the other hand, some forms of
plastic-film containers intended for one-time use have a seam that
forms a sealed spout. In that case, when the tip of the spout is
torn away, the spout is open permanently.
SUMMARY OF THE INVENTION
Pursuant to the present invention, a container is provided with a
spout formed of two supple films of thermoplastic material, the
films being joined together face-to-face along straight or curved
seams that converge toward a discharge passage. The spout is
proportioned with regard to the width of the discharge passage and
the shape of the spout to form a film-to-film seal across the
discharge passage, the seal being releasable in response to
internal fluid pressure pursuant to a notable aspect of the
invention. The walls of the portion of the spout leading to the
seal are distended, and they abut at the seal. The fluid pressure
required to release a pressure-releasable seal can be reduced by
pressing the distended walls of the spout closer together,
ultimately releasing the seal when the walls of the spout are
sufficiently flattened. The character of a pressure-releasable seal
varies widely with the shape of the spout-forming seams and with
the width of the discharge passage across which the seal forms.
Particular forms of the spout produce a continuous discharge of
liquid after the seal is released and until it is restored
deliberately, or brief discharges or "gobs" are dispensed in
response to pressure suddenly applied to the spout, or flow
continues so long as the container is squeezed, or a fine jet is
produced that breaks up into a spray. The spout can also be
proportioned to form a secure wall-to-wall seal that does not open
in response to practical levels of internal fluid pressure. Such a
seal can be rendered pressure-releasable by pressing the distended
walls of the spout closer together. In containers having spouts
proportioned to form either type of seal, the seams that join the
walls together should be free of corners directed toward the
container interior.
An object of the invention resides in providing novel containers
for many applications, having supple plastic-film walls joined
together face-to-face along fused seams that define a spout having
a discharge passage across which a pressure-releasable seal can
form directly between the walls of the spout.
A further object of the invention resides in providing a novel
container for liquids, the container having supple plastic-film
walls incorporating a spout that squirts liquid only so long as
internal fluid pressure is maintained and which seals itself when
the fluid pressure is relaxed.
A further object of the invention resides in providing a container
having supple plastic-film walls joined together by seams that
converge to form a spout in which a seal forms which is
pressure-releasable and which is self-restoring when the internal
seal-releasing fluid pressure is relaxed.
A further object of the invention resides in providing a novel
container for liquids, the container having a spout of supple
plastic-film walls shaped to form a seal that opens in response to
fluid pressure that develops when the container is squeezed, after
which the spout remains open so that liquid can continue to pour
until the seal is deliberately restored.
A further object of the invention related to the foregoing resides
in providing a novel container having flaccid plastic-film walls
and a passage that can be opened for filling and refilling the
container, where the passage is closed by a seal involving the
films alone, the container also having a separate discharge spout
closed by a wall-to-wall seal that opens to discharge fluid when
the container is squeezed, but without opening the seal of the
filling passage.
A further object resides in providing a novel dispenser including a
container having a self-sealing pressure-releasable spout and a
spout-pressing device that may be operated abruptly for effecting
limited-quantity discharges. Abrupt operation of the spout-pressing
device momentarily builds up the internal fluid pressure in the
spout so that a gob of liquid is discharged whereupon the seal is
self-restoring. Locating the pressing device near the seal reduces
the pressure needed to release the seal.
A further object of the invention resides in providing a container
having a flaccid-walled spout in which a releasable seal forms
between the walls of the spout, where the spout carries a removable
guard that inhibits unintentional opening of the seal.
A further object resides in providing a flaccid-film container
having a spout whose margins and discharge passage are proportioned
to form an especially secure seal across the discharge passage but
which does not open in response to all practical levels of pressure
safely below the bursting strength of the container. Such a spout
can be released by pressing its distended walls closer together
near the seal, thereby rendering the seal pressure-responsive; and
the seal can also be released by inserting a seal-parting device or
a funnel when the spout is to be used as a filling port for the
container.
A still further object of the invention resides in the provision of
a flaccid-walled container having a spout extending from the body
of the container, where at least the spout has marginal seams and
where all the seams of the container are free of corners directed
toward the interior of the container, thereby imparting high
strength for resisting internal liquid pressures.
A still further object of the invention resides in forming a
container of edge-seamed plastic films shaped to develop controlled
puckers that form a stable base.
The nature of the invention, including the foregoing and other
objects, novel features and advantages, are realized in several
illustrative embodiments of the invention in its various aspects,
which are described in detail below and shown in the accompanying
drawings. In these embodiments, two thermoplastic supple or flaccid
films are joined together face-to-face along edge seams to form a
container body and a spout that provides a discharge passage
extending outwardly from the body. A first portion of the spout
which adjoins the body of the container is readily distended by
contained fluid. Segments or elements of the seams along the first
spout portion converge in the fluid discharge direction. From
another point of view, those segments or elements of the seams that
extend along the first spout portion can also be regarded as
diverging generally toward the body of the container converge
toward and define a discharge. When the walls of the first spout
portion are distended by fluid, an arcuate bend forms in one of the
films extending across the discharge passage. The bend is prominent
at the center and vanishes toward the seams. This bend in one film
bears against the other film, to constitute a seal. In each
example, there is a second portion of the spout projecting
outwardly of the seal. Squeezing the container develops internal
fluid pressure that opens the seal where the spout is proportioned
to render the seal pressure-releasable.
In each of the described embodiments the seams of the first spout
portion converge in the fluid-discharge direction or, stated
another way, they diverge from an intermediate portion of the spout
generally toward the body of the container and the wall sections of
the first spout portion form what may be described roughly as
parti-conic shapes having narrow ends that abut one another when
distended by contained fluid so as to form a seal.
The seams are ideally formed at the very edges of the films. Such
seams are formed when the films are substantially face-to-face and
flat. When liquid distends the films, such edge seams contribute
flexibility that helps in achieving best sealing action in the
spout. Flexibility of the seams elsewhere around the container
contributes toward avoidance of unsightly puckers that tend to
develop in the container walls.
A special form of edge seam promotes success and consistency in
producing dependable releasable seals. This form of seam is formed
by holding a pair of thermoplastic films together face-to-face or
nearly face-to-face, concurrently but separately cutting the films
with a hot blade advancing along a cutting line to produce
overlying melted edges, and holding the films face-to-face as the
melted edges fuse together.
In one described embodiment where seams of the spout converge to a
small gap, having an inside width (excluding the seams) of
one-fourth inch or less, the seal opens when the container is
squeezed firmly. The seal tends to restore itself when squeezing
pressure is relaxed. Liquid in the container squirts out as a fine
jet stream, having many applications. An orifice is formed by
spread-apart film surfaces, resembling a slit in cross-section.
That form of small orifice resists clogging by particles of dirt or
solids in the liquid composition, whereas such particles might well
cause clogging in the case of a small round-bore discharge passage.
At some distance from the "slit" orifice, the jet stream breaks up
into a fine spray.
In each example, the seal must form at a location spaced from the
actual discharge orifice at the edge of the films. In described
embodiments where a container spout has seams that converge to a
discharge passage wider than one-fourth inch, the edge-seamed films
that form the spout project outwardly beyond the region of the seal
to form a distinct extension. Where seams converge prominently in a
spout that forms a pressure-releasable seal, the seal tends to be
self-restoring after internal fluid pressure is relaxed. In case of
a spout whose seams converge moderately, only enough to enable a
seal to be formed, and especially where the discharge passage is
relatively wide where it is closed by the seal, the seal tends to
remain open after it has been released. The location of the seal in
such ciruumstances tends to vary and by squeezing the container, it
is possible to shift the seal into the extension, and finally to
open the seal. Discharge of the liquid from such a container, once
started, continues under gravity pressure. To stop the flow, the
seal can be re-established by simple manipulation, or by inverting
the container.
In several embodiments detailed below, the liquid in a container is
dispensed when the container is squeezed firmly enough to develop
seal-releasing fluid pressure. The seal can be rendered easily
opened in response to only slight internal pressure by laterally
pressing and more-or-less flattening the spout. Thus, a supple-film
container of liquid with a self-sealing spout can be used as a
drinking vessel; and in that use, the container need be squeezed
only slightly to build up internal fluid pressure while the spout
is held and nearly flattened between the user's lips. A container
having a spout proportioned so that the seal is not
pressure-releasable can be used as a drinking vessel in the same
manner. In such applications, the container may be held
horizontally or even with the spout aimed upward. In a still
further distinctive embodiment, a supple-film container may have a
downward-directed spout between a support panel and a
pressure-applying plate. If the plate is pressed abruptly, the
inertia of the liquid in the container above the plate tends to
develop a large value of fluid pressure at the seal momentarily, to
dispense a gob of liquid. Pressing the plate also reduces the
distension of the walls of the spout and in that way lessens the
internal pressure needed to open the seal. With such a dispenser,
it is not necessary to squeeze the body of the container for
developing seal-opening pressure. The spout in this case should be
shaped to develop the self-restoring type of seal in this
dispenser.
In the described containers, the seal that forms is effective to
confine gases as well as liquids. Indeed the term "liquid" is used
in a non-technical sense to include not only true liquids but also
other fluent material comprising liquid that contains fine solid
particles, soft gels, etc. As will be seen, the materials to be
contained are limited essentially by their compatibility with the
material of the films. The seals develop partly as a result of
flexibility of the films which should be supple or flaccid, in this
respect contrasting with tinfoil and unplasticized cellulose
acetate, for example. A wide range of thermoplastic films are
suitable, such as polyethylene, polypropylene, and polyvinyl
chloride. Suitably supple films are stretched much more easily than
metal foil, but extremely elastic films as of very thin latex are
not recommended. In any case, the kind of seam that is needed seems
to dictate the use of thermoplastic films, as a practical matter,
whereas making tough seams between latex sheets is difficult.
A guard can also be provided to protect a spout with a releasable
seal, for maintaining a seal closed even though internal
seal-releasing fluid pressure is developed. Such a guard is useful
where a container has both a discharge spout and a filling spout,
and where the filling spout should remain closed while pressure is
developed to open the seal of the discharge spout. Such a guard is
useful even where there is only one spout, to avoid unintended
discharge when the container is squeezed incidental to
handling.
Where the whole container including the spout is formed of plastic
films joined face-to-face, the seam can be shaped to develop a
stable base for the container. Slant seam portions are included
between the seam at the bottom of the container and the seams along
its sides. Deep puckers tend to develop at these slant seams,
forming a gusseted container bottom to serve as a stable base.
It is possible and at times desirable to proportion the spout of a
container so that it forms a seal across the discharge passage,
which seal does not release or open when the container is squeezed
to develop internal fluid pressure within safe limits. Such a seal
can be an advantage where the container may be squeezed
inadvertently in handling, when fluid should not discharge. A seal
of this type can be rendered pressure-releasable in order to
discharge liquid deliberately, by forcing the walls of the spout
closer together. Seals of the spouts here involved are rendered
non-releasable in response to internal pressure by increased
convergence of the seams that shape the spout or by reducing the
width of the discharge passage where the seal forms, or both.
The nature of the invention, and its further objects, novel
features and advantages will be more fully understood and better
appreciated from the following detailed description of various
presently preferred illustrative embodiments of the invention in
its several aspects, those embodiments being shown in the
accompanying drawings.
In the drawings:
FIG. 1 is the front view of a container filled with liquid, as an
embodiment of various aspects of the invention, the container being
inverted and sealed, including phantom lines representing the
liquid-discharging, unsealed state of the container;
FIG. 2 is a side view of the container of FIG. 1, including phantom
lines representing portions of the container in liquid-discharging
state;
FIG. 3 is a greatly enlarged, fragmentary cross-section of part of
the container of FIGS. 1 and 2, as viewed from the section line
3--3 in FIG. 1;
FIG. 4 is a fragmentary front view of the bottom of the container
of FIGS. 1 and 2, when empty and flat;
FIG. 5 is a fragmentary front view of the bottom of the filled
container of FIGS. 1 and 2, resting on the bottom;
FIG. 6 is a bottom view of the container as shown in FIG. 5;
FIG. 7 is a greatly enlarged cross-section of the container of FIG.
1 as seen at the line 7--7;
FIG. 8 is a fragmentary view of the discharge end of the container
of FIGS. 1 and 2, when empty and flat;
FIG. 9 is the front view of a bottom plate that may be used with
the container of FIG. 1;
FIG. 10 is a fragmentary view of the bottom of the container as
shown in FIG. 5, equipped with the plate of FIG. 9;
FIG. 11 illustrates another embodiment of the invention, drawn to
reduced scale;
FIG. 12 is a fragmentary view of the embodiment of FIG. 11, drawn
nearly to full scale;
FIGS. 13, 14 and 15 show two cross-sections and an end view,
respectively, of a spout of the container in FIG. 12, as viewed
from the planes 13--13, 14--14 and 15--15 in FIG. 12;
FIG. 16 is a fragmentary view of one of the spouts in FIG. 12, as
seen when empty and flat;
FIG. 17 is a fragmentary view of a second spout of the container of
FIGS. 11 and 12, as seen when flat;
FIG. 18 is a fragmentary view of said second spout, as seen from
the plane 18--18 in FIG. 12;
FIG. 19 is a perspective view of a nozzle spreader, useful in
refilling the container of FIGS. 11 and 12;
FIG. 20 is the front elevation of a novel dispenser, as an
embodiment of further aspects of the invention drawn to reduced
scale; and
FIG. 21 is a cross-section of the dispenser of FIG. 20 as viewed
from the plane 21--21 therein.
Referring now to the drawings, container 10 includes a spout
including a spout portion 12, and an extension 14 projecting
outwardly and ending at discharge opening 16. Container 10 is
formed of two films of thermoplastic material, polyethylene for
example, united along their edges in a continuous seam 18. The
films 20 and 22 are face-to-face when the container is flat. This
face-to-face relationship is especially important at the seams
forming the margins of spout portion 12 and extension 14, as will
be seen. When flat, the films of the spout are congruent.
Seam 18 can be made by means of a blade having the outline of the
flattened container, heated to the fusing temperature of the
thermoplastic films and pressed against the films until the seam is
formed and the container is cut out along the seam. Such a seam can
serve the purposes of the present invention unless it is made with
techniques causing the films to diverge from the seam. Some slight
divergence adjacent the seam is tolerable, but ideally the films
should be in face-to-face contact.
In a preferred novel method, the seam may be made by means of a
heated blade that cuts along two face-to-face films, melting the
edges of the films as it cuts; and the films are held face-to-face
adjacent the cut edges long enough for the fused edges of the films
to merge into an edge seam. The desired face-to-face contact of the
films immediately adjacent the seams is easily realized by this
method.
The spout portion 12 and the extension 14 are divided at an arcuate
or fingernail-shaped seal 24, as viewed in FIG. 1. This seal is
formed by a bend 20a (FIG. 3) in film 20 which bears against film
22 with enough force to produce a noticeable bulge 22b in film 22.
The bulge is most noticeable, and the bend is most pronounced,
midway between the seams. The forces that develop seal 24 cause the
films to be displaced (FIG. 3) from a line extending from seam to
seam. Both films 20 and 22 are warped surfaces in the region of
seal 24. In addition to the arcuate form of seal 24 as shown in
FIG. 1, the seal has another curvature relative to an imaginary
unwarped surface extending seam-to-seam in the region of the seal
24. It is this latter curvature that is responsible for the offset
between seam 18 and seal 24 in FIG. 3. The bend 20a is prominent
midway between the seams, and decreases toward the seams.
Immediately adjacent the seams there is no noticeable bend 20a, and
it is at those points that the face-to-face relationships between
the films is important. The forces producing the seal can overcome
only a slight amount of natural divergence that could exist between
the films at each seam.
The physical proportions of spout portion 12 have dominant
influence on the formation of seal 24 and on the nature of the
seal. As seen in FIG. 3, when liquid distends walls 20 and 22, each
of the walls slopes toward the other. Provided that the angle
between films 20 and 22 is not too great, a particular kind of seal
is produced which opens when the container is squeezed, i.e., an
internal pressure-releasable seal. Where seams 18 are symmetrical
at opposite sides of medial plane 3--3 of FIG. 1, the angle between
the distended films when measured at the medial plane, is largely
determined by the shape and spaced relationship of the seams.
(While only one continuous seam forms the entire container of FIGS.
1 and 2, it is convenient to use the plural term "seams" in
referring to spout portion 12 and extension 14.) The medial plane
passes through walls 20 and 22 along the centerlines of the spout
portion 12 and the extension 14. More generally, the "centerlines"
of a spout extend along the walls midway between the seams and, as
represented in FIG. 3, the centerlines of the readily distendable
wall sections adjacent the abutment (disregarding bends 20a and
20b) form an angle of less than about 90.degree.. The sections of
the walls below bend 20a coextend, and their centerlines are in
general alignment with the centerline of one of the wall sections
above bends 20a and 20b and at an angle to the centerline of the
other wall section above bands 20a and 20b. Seams 18 forming spout
portion 12 converge toward extension 14, and the seams reach a
point of minimum separation. As seen in FIG. 8 (which represents
spout portion 12 and nozzle 14 when the films are flat), each seam
18 is continuous, and it is curved along a radius R having a center
C. The minimum separation of the converging seams that form spout
portion 12 and extension 14 occurs at a gap G. In an example,
radius R of both seams 18 is three inches and gap G is 3/8 inch,
measured across the outside dimension of the nozzle. Each seam in
this example is about 0.030 inch wide where films 20 and 22 are
polyethylene films of about 0.004 inch thick, joined by the
preferred method described above.
When the container with this spout is filled, seal 24 forms above
gap G, and this seal is formed at a wider part of the spout than
the 3/8-inch width of gap G. For convenience, the width of a seal
may be taken to be the width measured across the apex of the seal,
from seam to seam. Further, while the width of a seal is not
critical except in the one-fourth-inch range, the widths given here
and elsewhere in this specification represent outside dimensions
unless stated otherwise. Likewise, the seams in all of the
described embodiments are made by the preferred method described
above and are about 0.030-inch wide.
Such a seal is pressure-releasable, provided that the wall-to-wall
or film-to-film angle above the seal is not too great. This
wall-to-wall angle is measured at the median plane 3--3 (FIG. 1)
between the seams. The wall-to-wall angle is in turn determined
mainly by the convergence of the portions of the seams above the
seal 24 and by the separation between the seams at the seal.
Films 20 and 22 exhibit a limited degree of elasticity, a quality
associated with the supple quality of the film. The elasticity of
the films is demonstrated by the warping of the films that occurs
as shown in FIG. 3, and it is further demonstrated by the fact that
spout portion 12 is not puckered when distended by liquid even
though seams 18 in the embodiment of FIGS. 1 and 8 are not straight
but curved. Strips of 0.004 inch thick and 1.0 inch wide
polyethylene film used in making spouts with excellent seals (as in
FIG. 3) showed 10 percent elongation when tested with a six-pound
weight. The same film when subjected to a softening heat treatment
exhibited 10 percent elongation for a one-inch wide strip when
subjected to a test weight of 0.6 pound. The latter film when
formed into a container having a self-sealing spout showed a
tendency to allow opening of the seal in response to lower
pressures than in the case of the less stretchy film.
When the walls of the spout are distended as in FIGS. 1-3, each
wall forms an approximation of part of a cone. Seal 24 is formed
where the tips of these parti-conic wall shapes meet. The seal in a
spout of the above proportions is releasable in response to
internal fluid pressure resulting from squeezing the container. Of
course, the seal-releasing pressure must be safely below the
bursting strength of the container.
When the seal is in the position represented by the solid line 24
in FIG. 1, extension 14 characteristically slants to one side, as
shown in FIGS. 2 and 3. Squeezing the container causes seal 24 to
shift toward exit opening 16. The seal reaches a limiting position
24', after which the liquid in the container starts to pour out of
extension 14. This continues in the case of a spout having the
dimensions given above even if the container is no longer squeezed
after pouring starts. The spout is in the condition represented by
phantom lines in FIG. 2. Flow stops and seal 24 forms again, when
the extension is pushed back to the solid-line position of FIG. 2.
This usually requires only a light stroke of a finger.
Container 10 can be supported by a hanging tab or by a fixture of
some form or by the grasp of a person's fingers, using care in any
case to avoid imposing enough squeezing pressure to open seal 24
unintentionally. Effective support can be disposed under the
shoulders 18b formed where the seals 18 of spout portion 12
approach the bulk of the container The support should not be
located so as to flatten the spout, since reducing the film-to-film
angle of any given spout reduces the pressure needed to open the
seal and then gravity pressure of the liquid could be enough to
start the discharge of liquid.
The portions of seams 18 along the spout portion 12 far from seal
24 have little effect on formation of the seal. The greatest effect
results from the convergence of the seams 18 in the region above
the minimum separation G. Tangents to the seams 18 of the flattened
spout above gap G (FIG. 8) have an angle A between them. This angle
could be made so large that the seal would not open when pressure
(within practical limits) is applied to the container. The angle
could be so small that pressure amounting to no more than the
hydraulic head of the liquid in the container would be enough to
open the seal. A practical range of angle A is from about 5.degree.
for a seal width of 1/8 inch to about 140.degree. for a seal width
of about 11/4 inch, to produce pressure-releasable seals.
The shape of spout portion 12 is thus of controlling importance to
formation of a seal and to the character of the seal that is
formed. Where the marginal seams 18 of te spout related to each
other by an angle much larger than 140.degree. (this angle being
measured with the container empty and flat) then a seal would form
but it would not be pressure-releasable except possibly by such a
large value of pressure that the container would be in danger of
being ruptured.
The angle A may not always be easy to measure since the seams 18
that form spout 12 need not be straight or nearly straight. The
seams may be curved prominently as part of a circle or some other
curve. In that case it may be hard to determine angle A. The
relationship between seams 18 of the spout which is necessary to
develop a pressure-releasable seal can be expressed in another way,
as indicated above. The seams that define spout 12 are so related
to each other that when the container is full, the angle between
the centerlines of the mutually abutting films adjacent to the seal
(disregarding bends 20a and 22a) is a maximum of about 90.degree.
measured between the centerlines of wall sections 20 and 22 as
represented in FIG. 3. This wall-to-wall angle of 90.degree. is
applicable to a spout having a seal whose width (measured from seam
to seam along a line tangent to the apex of the seal) is large,
11/4 inch, for example. For spouts having narrower seals, the
wall-to-wall angle should be less than 90.degree.. A
pressure-releasable seal forms across a spout having a wall-to-wall
angle of about 85.degree. where the seal is 11/8 inch wide. Such a
spout can be made with curved seams 18 (FIG. 8) having radii of
about one inch. A pressure-releasable seal having a wall-to-wall
angle of about 75.degree. is formed across a spout whose seal width
is 3/4 inch and whose marginal seams 18 (FIG. 8) have radii of
about 11/2 inch. Pressure-releasable seals are formed across spouts
whose seal widths are in the range of 1/4 inch to 5/8 inch where
the wall-to-wall angle adjacent the seal is in the range of about
45.degree. to 75.degree.. A pressure-releasable seal is formed
across a spout whose width (measured across the wall surfaces to --
but not into -- the seams) is 1/16 inch to 1/4 inch where the
wall-to-wall angle is in the range of about 5.degree. to
45.degree.. In these examples, the smaller wall-to-wall angles are
related to the narrower seals. For these spouts to form
pressure-releasable seals, the seams 18 converge at a small angle
A, whether straight or long-radius seams are used.
Along with this discussion of spout and seal parameters, it is
pertinent to note that spouts having different seal widths behave
differently. Seals in the 1/16 to 1/4 inch range produce a squirted
jet stream. The jet is flat where it emerges from the external
opening of the nozzle spout extension, pulls closer together a
short distance from the opening and forms a spiral, and then the
jet breaks into tiny droplets that are not so fine as to become
suspended in air but which form a fine spray that is useful for
many purposes. Optimal wall-to-wall angles can be developed using
seams 18 that have long radii or are straight, and have
seam-to-seam angles A in the range 10.degree. to 45.degree.. When a
"squirter" container is used, the seal 24 is opened by
squeeze-induced pressure, and the seal forms again as soon as the
squeeze is interrupted. Similarly, in the case of seals 1/2 to 7/16
inch wide, a limited discharge of liquid is produced, continuing
only while the container is squeezed, and then resealing occurs. In
case of pressure-releasable seals appreciably wider than 7/16 inch,
once they are open they tend to remain open until the seal is
restored, for example in the manner described above in connection
with FIG. 2. As previously noted, the term "seal width" is the
width of the seal that forms in any given spout when its walls are
freely distended, and where the width is measured along a line from
seam to seam and tangent to the apex of the seal. These widths are
inexact, inasmuch as many factors have secondary modifying effects.
For example, two such factors are the stiffness and the thickness
of the film material. The figures above were obtained with
polyethylene about 0.004 inch thick.
Seam 18 as described above is formed at the edge of the plastic
walls that constitute the container. This factor contributes to the
formation of the seal 24 and it contributes to the avoidance of a
great many puckers along seam 18. In contrast, the seam could be
formed along a line spaced inward from the edge of the plastic. Any
extension of the films outside the seams develops physical
resistance to bending of the seam. Where the films are joined by
seams spaced from the edges of the films, puckering tends to occur
where portions of the seams that form extension 14 merge into the
portions of the seams that form spout portion 12. The walls of
extension 14 are essentially flat and the walls of spout portion 12
are distended, so that what was a smooth-line seam (FIG. 8)
develops an undulation 18a (FIG. 1). The fact that the seam is at
the edge avoids stiffness, or gives the seam a suppleness that
promotes the formation of smooth bends in seams 18.
When container 10 is not in use, it can be laid on its side. In so
doing, care should be taken not to distort the walls that form the
spout. A better way to store container 10 is upright. This is
facilitated by enabling the walls of the container to form a flat
bottom as shown in FIGS. 5 and 6. Where the body of the container
is formed of the same two plastic sheets that form the spout, it
can be shaped as shown in FIG. 4, to have more-or-less parallel
side portions 26, a transverse end 28 and 45.degree. slant portions
30 between portions 26 and 28, forming corners 32 and 34.
Transverse end 28 occupies about 40-80 percent of the bottom. When
the container is filled, a deep pucker or gusset 33 tends to form
(FIGS. 1 and 2) in the container due to the described shape. A flat
bottom is formed in this way, on which the container can rest.
The stability of the gusseted bottom depends somewhat on the
proportions of the container as a whole. A wide plate 35 as of
sheet-metal or plastic (FIG. 9) can be used to improve the
stability of the container when resting on its bottom. Plate 35 has
turned-in margins 38 extending from a flat base 36. Margins 38 are
received in the tucks of gussets 33 (FIG. 10) when the plate is
assembled to the container bottom. Plate 35 imposes a flat shape on
the container bottom that resists any tendency of the upright
container to roll over. Moreover, plate 35 can be made amply wide.
Preferably, it is appreciably wider than the small dimension of the
container bottom, the vertical dimension as seen in FIG. 6.
Container 10 equipped with base plate 35 can be deposited upright
without concern about toppling.
Container 40 in FIGS. 11 and 12 includes a squirting spout 42 and a
filling spout 44. This container is useful for window-cleaning
fluid, lubricating oil, etc.
Spout 42 when flat has the proportions shown in FIG. 16, for
example. At the tip or discharge orifice 47, the spout (there being
no distinct nozzle here the container being flat) is 3/16 inch wide
for example, this being the outside measurement including the
orifice 47 and two seams. The width of the flattened spout at a
distance of one inch from the discharge orifice is about 13/16 inch
in this example, and seams 46 (formed the same way as seams 18)
having such long-radius curvature that they are approximately
straight, and they converge at an angle of about 25.degree.,
measured when flat.
When the container including spout 42 is full, the walls of this
spout are fully distended and this causes a seal 48 to form about
3/16 inch from orifice 47. The portion of the spout extension
between the seal and the orifice is tilted, as in FIG. 3. Squeezing
the container produces a fine and long jet stream from spout 42.
The stream is essentially flat immediately adjacent to orifice 47.
It becomes narrower and thicker a short distance from orifice 47,
and a spiral twist develops in the jet stream. The jet has a long,
relatively straight trajectory, and ultimately it breaks up into a
tight-angled spray amounting to a ray of tiny droplets. The width
of seal 48, measured along a line tangent to the apex of the seal,
is about 1/4 inch including the passage and both seams. When
pressure in the container is built up progressively, the seal
shifts toward orifice 47 and finally the seal opens and a jet of
liquid is delivered at orifice 47. As soon as the pressure is
relaxed, the jet is interrupted and the spout becomes sealed, of
itself.
Spout 44 of container 40 is shown flat in FIG. 17, and it is shown
filled and distended in FIG. 18. Spout 44 extends to a flaring
orifice 50. A spreader 52 for the orifice is shown in FIG. 19,
having a curved wall 54 and a rib 56, tapered to a thin and narrow
blade-like tip 58. Spreader 50 can be inserted in spout 44 which
then can serve as a funnel to help in filling the container.
Orifice 50 can be made as wide as may be considered necessary for
this purpose. The length of spreader 52 should be such that, when
inserted into spout 44, it has a part projecting from orifice 50
and, at the same time, the tip 58 should extend deep enough into
the spout so that rib 56 opens the passage so that liquid can
enter. A straw or a separate funnel can also be used to refill
containers such as those of FIGS. 1 and 11, even where the spout is
not flared as described above. The "self-contained funnel"
represented by the flared spout 44 of FIG. 17 is a distinct
advantage.
The radii R of the seams that form the portion of spout 44 that is
filled when pressure develops in the container should be small
(e.g. 1/4 inch), and the minimum separation between the marginal
seams should also be small (e.g., 5/16 inch) where a seal is to
develop in spout 44 that does not open in response to pressure
sufficient to produce a jet spray from spout 42. Notwithstanding
this proportion, spout 44 can still be used as a filling passage.
Too-sharp radii for the spout should be avoided, in order to guard
against tearing stresses when the container is squeezed.
As a safeguard against unintentional near-flattening of spout 44
such as might occur in handling, with the result that the seal
would open and liquid could leak out, a security clip or guard 60
is applied to spout 44. Two side walls 62 extend at an angle from
the middle portion 64 of guard 60, and a tongue 66 is bent and
extends integrally from middle part 64, between -- and spaced from
-- side walls 62. Tongue 66 does not disturb the seal formed in
spout 44, but the tongue holds the whole guard in place on spout 44
as shown in FIGS. 12 and 18. Walls 62 protect the spout against
pressure such as would reduce the angle of its walls. Were the
walls of the spout pressed close to each other, the kind of seal
represented in FIG. 3 would not exist and liquid could escape. The
purpose of guard 60 is to protect the seal that forms inherently
when the spout is distended. Guard 60 can be proportioned relative
to the spout to develop an angle between the walls (see FIG. 3)
that form the seal, thereby enhancing the effectiveness of the
seal, but no effort is made here to rely on guard 60 to squeeze the
walls of the spout together, to create a totally different kind of
seal. It is to be understood that other means may be used to keep
spout 44 sealed when container 40 is squeezed for producing a
jet-spray. The described self-sealing spout and guard form a
distinctive novel sealing means having evident practical merit.
Guard 60 (properly proportioned) is valuable for protecting the
spout of the container in FIGS. 1 and 2 against unintentional
opening of the seal and escape of liquid.
A distinctive form of dispenser embodying features of the foregoing
embodiments and certain additional features is illustrated in FIGS.
20 and 21. That dispenser includes container 70 formed of supple
films as of 0.004 inch polyethylene edge-seamed together as
described above to form a body portion 72, a dispensing spout 74
and a filling "spout" 76. A spring-biased clip 78 clamps the upper
part of container 70 against a panel, so that spout 74 aims
downward when panel 80 is upright.
A resilient strip 82 as of metal or plastic has end portions 84
that grip the edges of panel 80, enabling the strip to slide along
the parallel lateral edges of panel 80 and to retain any adjusted
position on the panel. Strip 82 has a portion 86 that is arched
over a portion of container 70 above seal 94. Portion 86 carries a
knob 88 which, when pushed, causes strip portion 86 to act as a
device that applies pressure to the container above the seal 94. In
an example, spout 74 has a discharge orifice 90 that is 3/16 inch
wide and edge seams 92 that diverge such that the container is 1
5/8 inch wide measured 11/2 inch from orifice 90. In this instance,
the width of the orifice is measured internally so as not to
include the edge seams 92. Pressure device 84 is disposed with its
lower edge 3/4 inch from orifice 90 and is 5/8 inch wide where it
spans container 72. A seal 94 that is 5/16 inch wide (measured from
seam to seam) tends to form above orifice 90.
It may be assumed that container 72 contains liquid up to one-half
of its top-to-bottom dimension, thereby causing the spout and the
portion of the container underlying pressure device 84 to be
distended (see FIG. 21). Abrupt pressure applied by hand to knob 88
and pressure device 86 deflates the underlying part of the
container. This forces the liquid in the container to rise
suddenly. The inertia of the liquid above pressure device 86
resists this upward displacement, causing an abrupt rise of
pressure in spout 74. This pressure momentarily opens the seal in
spout 74 and causes a gob of liquid to be discharged. The pressure
is momentary, and the seal is self-restoring after the momentary
discharge occurs.
With pressure device 86 located as stated above, there is a
tendency for spout 74 to become resealed after the momentary
discharge occurs even if pressure against knob 88 is maintained.
The pressure member can be shifted upward, to increase the volume
of the discharged gob of liquid. Pressure member 86 could be
shifted downward a bit, but if that were done then seal 94 would
probably remain open and discharge of liquid would continue, until
the pressure applying device is released and the walls of the spout
are allowed to become distended, so that the wall-to-wall seal in
spout 74 restores itself.
The dispenser of FIGS. 20 and 21 is useful as a dispenser for many
liquids, such as liquid soap or lotion or antiseptic liquid. Little
or no instruction is needed to new users. The elemental simplicity
of this dispenser, its low cost, and its immunity to becoming
inoperative, as compared with usual soap dispensers (for example),
are at once apparent.
Container 70 may be refilled at spout 76, as with an inserted
funnel. Alternatively, the container may be discarded when empty
because of its very low cost; and in that case, a factory-filled
container may be substituted. For absolute assurance against
leakage from the spout before a factory-filled container is to be
used, the discharge spout and the filling orifice may be sealed by
a fused seam like seams 92. The seam closing the tip of spout 74
may be removed with a sharp blade when the new container is mounted
for use.
It has been found that a shear cut across the spout, made by
scissors for example, tends to form a seal in the nature of a cold
weld. Such a seal may be used in place of a fused seam to prevent
unintended discharge of liquid from both spouts in the course of
handling container 72, before it is put to use. When a container
having a spout that is sealed by a shear cut is to be readied for
use, that seal can usually be opened by squeezing the walls of the
spout together, then using the fingers to force a small volume of
liquid outward, in a "milking" motion.
The applications of the described embodiments of the invention are
endless. For example, the container of FIG. 1 can be used by a
person confined to bed, as a drinking vessel. The user's lips can
flatten the walls of the spout just enough to allow the seal to
release liquid from the container when the spout is aimed upward
and the container is gently squeezed. The container can be refilled
via the discharge spout.
All kinds of liquids may be contained, it being required only that
the film used with any particular liquid should be non-porous and
neither permeable nor attacked by the liquid. In cases where a
particular liquid dissolves a given plastic film, then a different
film should be selected. In some instances, liquids merely soften
the films to a limited degree. To preserve the form of the
container and its spout despite softening effects of a particular
liquid, it may be useful to resort to laminated films, for example,
an extruded laminate of polyethylene containing a layer of 0.00025
polyvinyl chloride (Saran) bonded between layers of the
polyethylene contributes the property of resistance to the solvent
effect of certain liquids to be dispensed. While a material such as
polyethylene terephthalate (Mylar) in a thickness of 0.004 inch
might not be sufficiently supple to form a seal across a spout,
such a material is useful as an extremely thin layer in an
otherwise suitable laminate.
The pressure-releasable type of seal has been discussed above at
length in connection with the illustrative embodiments shown in the
drawings. However, it is not necessary in all cases to provide a
pressure-releasable seal. For example, where a spout is provided
for use as a filling orifice (e.g., spout 44 in FIG. 12 and spout
76 in FIG. 17), it may well be desirable for the seal to remain
closed even when high pressure is developed in the contained
liquid, below the bursting strength of the container. There are
definite advantages to a spout that forms a seal across its
discharge passage, where the seal is non-responsive to internal
fluid pressure within practical limits. For example, the spouts 12
and 42 in FIGS. 1 and 11 can be proportioned so as to render their
seals non-responsive to internal liquid pressure. Such spouts are
thus made secure against unintentional release of liquid when the
container is squeezed in handling. A dispensing container in the
form shown in FIG. 11 and carried in a shirt-pocket is subject to
being squeezed unintentionally when the wearer's jacket is
accidentally bumped and when the seal should remain closed. Such a
container is useful for squirting lubricating oil, antiseptic
liquid such as alcohol, etc., and in such uses, it may be important
to provide security against the liquid discharging
unintentionally.
In each of the examples above, the container has a spout having
converging seams proportioned to form a seal across the discharge
passage. In those embodiments, the seal can be rendered
non-releasable in response to internal liquid pressure by making
the discharge passage narrower where the seal forms, or by making
the angle of convergence wider or by using a shorter radius of
curvature in forming the seams along the margins of the spout. (The
wider angle of convergence and the shorter radius of curvature of
the seam are two ways of producing more prominent convergence.)
Further, the proportions of any given spout can be modified to
render the seal non-releasable in response to practical limits of
internal pressures, by both reducing the seal width and increasing
the prominence of the seam convergence.
A dispensing nozzle such as that of FIG. 1 or that of FIG. 11 when
proportioned so as to be inherently non-releasable in response to
internal fluid pressure alone can be used for dispensing liquid by
applying collapsing force against the distended walls of the spout
near the seal. Thus, the user can grasp the container with one hand
and can use his thumb and forefinger or his lips to reduce the
distension of the walls. This has the effect of making the seal
pressure-releasable. Then the user can squeeze the container to
dispense liquid.
In making such a spout, and indeed as a general rule, care should
be used to avoid sharp corners whose apexes are exposed to or
directed toward the interior of the container. This applies not
only to the seams of the spout but also where the spout meets the
body of the container, and generally throughout the container. Any
such corner causes a concentration of stresses to develop in the
wall of the container when exposed to internal pressure, risking
rupture when the container is first squeezed or when the container
has become stretched or weakened near such a corner after the
container has been squeezed repeatedly. Even sharply curved seams
that arch toward the container interior should be avoided in the
case of containers that may be subjected to hard squeezing. As a
practical limit in such containers, inward curves should not have a
radius of less than about one-half inch.
From the foregoing it is evident that the described illustrative
embodiments of the invention in its various aspects, and their
variants, can be altered and can be given a wide range of
application by those skilled in the art. Consequently, the appended
claims should be construed broadly, in accordance with the full
spirit and scope of the invention.
* * * * *