U.S. patent number 3,918,131 [Application Number 05/431,234] was granted by the patent office on 1975-11-11 for fluid-tight fastener.
Invention is credited to Steven Ausnit.
United States Patent |
3,918,131 |
Ausnit |
November 11, 1975 |
Fluid-tight fastener
Abstract
A fluid-tight fastener comprising a pair of flexible closure
strips each having a web portion and a marginal strip portion, at
least the marginal strip portions being formed from strongly
resilient material. The marginal strip portions have respective
complementary longitudinal interlocking ribs and grooves, the ribs
being wider than the grooves and the grooves deeper than the height
of the ribs so that the ribs as received in the grooves cause the
grooves to expand and bridges connecting the sides of the grooves
to stretch and react under tension and to place the ribs under
compression, whereby the ribs are sealingly gripped in fluid-tight
relation within the grooves.
Inventors: |
Ausnit; Steven (New York,
NY) |
Family
ID: |
23711051 |
Appl.
No.: |
05/431,234 |
Filed: |
January 7, 1974 |
Current U.S.
Class: |
24/586.1;
24/DIG.39 |
Current CPC
Class: |
B65D
33/2541 (20130101); A44B 19/16 (20130101); Y10T
24/45173 (20150115); Y10S 24/39 (20130101) |
Current International
Class: |
A44B
19/10 (20060101); A44B 19/16 (20060101); A44B
019/10 () |
Field of
Search: |
;24/21C |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gelak; Bernard A.
Attorney, Agent or Firm: Hill, Gross, Simpson, Van Santen,
Steadman, Chiara & Simpson
Claims
I claim as my invention:
1. A fluid-tight fastener, comprising:
a pair of flexible closure strips each having a web portion and
provided with a marginal strip portion;
at least said marginal strip portions being formed from strongly
resilient materials;
one of said marginal strip portions having at least one solid
form-retaining longitudinal rib provided with an undercut
interlacking tooth along one side thereof thereby forming an
enlarged head, said head having a relatively flattened crown
surface and arcuate sides;
the other of said marginal strip portions having a longitudinal
groove with an undercut longitudinal tooth along one side thereof,
said groove having an arcuate root surface, said groove also having
arcuate sides generally complementary to said arcuate sides of said
head;
said rib being releasably engaged in said groove with said teeth in
interlocked engagement and with said arcuate root surface and said
crown surface forming a space therebetween;
said rib being wider than the normal width of the groove and
causing the groove to expand laterally; and
a bridge of said other marginal strip portion joining the opposite
sides of the groove and including said arcuate root surface
overlying said crown surface of said rib, said bridge being
stretched by the lateral expansion of the groove and thereby
reacting under tension to draw said groove sides tightly against
the rib;
whereby the rib is sealingly gripped in fluid-tight relation by and
between said groove sides.
2. A fastener according to claim 1, wherein said bridge is
deflected toward the crown surface of the rib in the stretched
tensioned condition of the bridge.
3. A fastener according to claim 1, wherein the stretching tension
of said bridge is controlled by the thickness of the bridge.
4. A fastener according to claim 3, wherein said bridge is
relatively thin so that the bridge is stretched with only moderate
tension.
5. A fastener according to claim 3, wherein said bridge is
relatively thick and the stretching thereof effects a strong
tensioned reaction for gripping of the rib.
6. A fastener according to claim 1, wherein each of said marginal
strip portions has a plurality of said longitudinal ribs and a
corresponding plurality of said longitudinal grooves and bridges,
with the ribs of each of said marginal strip portions received in
and expanding the grooves in the opposite marginal strip portion,
and thereby providing multiple rib and groove gripping fluid-tight
sealing of the fastener.
Description
This invention relates to improvements in resilient fasteners that
provide flexible closures of a variety of different uses such as on
brief cases, pouches, wrappers, and the like, and is specifically
concerned with a new and improved fluid-tight fastener.
As heretofore constructed resilient fasteners of the type of the
generally interlocking rib and groove structure, sometimes also
referred to as slide fasteners, have generally been constructed
with some looseness in the assembly. Representative of this type of
fastener in the prior art is Madsen U.S. Pat. No. 2,713,421 wherein
clearance is provided over the crowns of the ribs to enable the
fastener strips to engage more readily as well as to permit
relative sliding movement longitudinally between the strips.
Fasteners as just described are not leak proof so that where a
fluid-tight (either vapor or liquid) closure is required some other
type of closure would be required, although a resilient fastener
might be more convenient and advantageous.
One manner of solving the problem is represented in prior patent to
Staller U.S. Pat. No. 3,440,696. Therein is disclosed the provision
of a relatively soft sealing thermoplastic substance placed under
compression during engagement of the rib and groove elements.
However, that solution complicates manufacture of the fastener,
requiring bringing together of materials of different durometer
characteristics, rather than making the fastener from a single
material as is conventional practice.
Accordingly, there has been a long felt need for a fluid-tight
fastener which will provide a vapor lock or hermetic seal, but
which can be manufactured according to conventional practices
comprising extruding the parts from a suitable plastic material of
uniform characteristics suitable for the intended purpose.
An important object of the present invention is to provide a new
and improved resilient fluid-tight fastener which may be used as a
closure for pouches, containers, wrappers, and the like, for
enclosing articles and substances that must be protected against
atmospheric, water or other deteriorating conditions or, on the
other hand, must retain within the enclosure a fluid substance
without any leakage hazard.
Another object of the invention is to provide a new and improved
fluid-tight fastener which automatically provides a fluid barrier
between sheeting sections upon securing interlocking groove and
fastener elements secured thereto.
A further object of the invention is to provide a new and improved
resilient fastener wherein a novel tensioning and compression
relationship is provided in the closed fastener such that the
elements thereof provide with the other portions of the fastener a
fluid-tight barrier.
Still another object of the invention is to provide a new and
improved fluid-tight fastener which can be manufactured according
to conventional techniques from preferred conventional materials
and to be manipulated into closed and open conditions by
conventional means, but which automatically seals against fluid
leakage therethrough in the assembled condition of the
fastener.
Other objects, features and advantages of the invention will be
readily apparent from the following description of certain
preferred embodiments thereof, taken in conjunction with the
accompanying drawing although variations and modifications may be
effected without departing from the spirit and scope of the novel
concepts embodied in the disclosure, and in which:
FIG. 1 is a fragmentary sectional isometric view illustrating a
fluid-tight fastener embodying features of the invention;
FIG. 2 is an exploded assembly view of the fastener showing the
same with the complementary portions thereof separated and
schematically illustrating certain features contributing to the new
and improved results attained with this fastener;
FIG. 3 is an enlarged sectional view through the fastener assembled
together and schematically illustrating how the parts of the
fastener stretch in the assembly to attain the desirable
compressive sealing reaction therein; and
FIG. 4 is a transverse sectional view showing a modification.
On reference to FIG. 1 a fluid-tight fastener 5 embodying features
of the invention is depicted comprising a pair of complementary
flexible closure strips 7 and 8 each of which has a web portion 9
provided with a marginal strip portion 10. Although the web portion
9 and the marginal strip portions 10 may be constructed from
different materials, but with at least the marginal strip portions
10 formed from strongly resilient material, in the construction
shown both the web portions 9 and the marginal strip portions 10
are formed integrally in one piece as an extrusion made from a
suitable durometer thermoplastic material. Relative flexing
movement between the portions 9 and 10 of each of the strips is
facilitated by the provision of a longitudinal groove 11 between
the web portion 9 and the marginal strip portion 10 in each
instance.
For separable interlocking of the marginal strip portions 10 they
are provided with respective, complementary longitudinal
interlocking ribs 12 and grooves 13. Each of the marginal strip
portions 10 is provided with at least one rib 12 and one groove 13,
but in a preferred arrangement as shown, each of the marginal strip
portions has two ribs and corresponding grooves. Each of the ribs
12 has arcuate sides generally complementary to arcuate sides of
the groove 13 in which received, and an undercut tooth formation 14
along one side thereby forming an enlarged head and which is
complementary to and releasably interlockingly interengagable with
the like tooth along one side of the groove 13, provided by the
head of the counterpart rib 12 in the fastener assembly.
According to the present invention, the construction and
relationship of the interlocking ribs 12 and grooves 13 is such
that in the assembled relationship the ribs 12 are sealingly
gripped in fluid-tight relation within grooves 13. For this
purpose, the ribs 12 are of solid form-retaining, construction
(although resiliently flexible) and are wider than the normal width
of the grooves 13 so that the ribs as received in the grooves cause
the grooves to expand and areas of the marginal strip portions 10
at the grooves to stretch and react under tension to place the ribs
12 under compression. On reference to FIG. 2, for example, it will
be observed by comparing the full line and the dash line
representations of the strips 7 and 8 that the sides of the grooves
in the unassembled normal condition of the marignal strip portions
10 are significantly narrower than the width of the ribs 12.
Therefore, when the ribs 12 are forced into the grooves 13 until
the teeth 14 interlock, the sides of the grooves 13 must move apart
to accommodate the mass of the inserted ribs 12. This causes areas
of the marginal strip portions 10 at the grooves, and more
particularly bridge portions 15 of the marginal strip portions 10
connecting the ribs 12 with one another and with the web portions 9
to stretch and elongate transversely, as indicated by the full line
showing in FIG. 3 as compared to the dot-dash illustration therein.
By reason of the resilient characteristics of the material of the
fastener, such stretching causes a corresponding reaction due to
the tension generated tending to pull the sides defining the
grooves 13 back toward their normal position, resulting in placing
the sides of the ribs 12 under compression between the sides
defining the grooves. As a result, the side surfaces of the ribs 12
and of the grooves 13 are in tight gripping relation and
effectively hermetically seal the fastener 5.
To facilitate the stretching and tensioning of the bridges 15, the
relative shape and relationship of root surfaces 17 in the grooves
13 and confronting crown surfaces 18 on the heads of the
interlocking ribs 12 are so relatively shaped as to leave freedom
of relative movement therebetween during the assembly of the ribs
into the grooves. To this end, the root surfaces 17, in the grooves
13, are arched away from the ultimate position of the crown
surfaces 18 and further, the crown surfaces 18 are relatively
flattened so that a spaced relationship between the root surfaces
and the crown surfaces persists after assembly has been completed,
as is seen in FIGS. 1 and 3. It will be observed that while the
crown surfaces 18 remain substantially in their original shape, the
root surfaces 17 tend to flatten somewhat and pull in toward the
crown surfaces 18 as the bridge areas 15 pull in toward said crown
surfaces 18 by reason of the stretching of the bridge areas.
A reasonable degree of control upon the stretching characteristics
of the bridge material of the interlocking marginal portions of the
fastener may be effected by the thickness of the bridge in any
instance. For example, in FIG. 4 the bridges 15' are shown in full
line as substantially thinner than the bridges 15 indicated in dot
dash line and corresponding to the bridges in the form of FIGS.
1-3. In other respects the fastener remains the same and therefore
identical reference numerals indicate identical parts according to
foregoing description. Thus by having the bridges 15' thinner, a
softer easier stretch is attained. Of course, by the same token, by
increasing the thickness of the bridge in any instance increased
resistance to stretching and a tighter leak-proof grip on the
interlocking ribs can be attained, though if the bridge is too
thick, no stretching will be possible and the fastener will not
close.
In any form of the invention, the fastener is adapted to be opened
and closed by means of any preferred form of slider. When closed, a
thorough hermetic seal is provided against internal or external
leakage of fluid F, shown for illustrative purposes in FIG. 1 as a
liquid on one side only of the fastener. The fluid F may, of
course, be on both sides of the fastener where mixing or
contamination of one fluid by another must be avoided as, for
example, where a sealed package containing fluid must be stored or
transported in another fluid. Also, the fluid may be in a vapor or
a gaseous phase or liquid phase.
It will be understood that variations and modifications may be
effected without departing from the spirit and scope of the novel
concepts of this invention.
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