Extended film seal for ostomy appliance

An ostomy appliance including a collection pouch and a faceplate, each equipped with a flexible plastic coupling ring for detachably joining the faceplate and pouch. One of the rings includes a neck portion that protrudes through the opening of the other ring when the two are coupled together. An annular web of thin, flexible, stretchable plastic material is secured to the backside of the receiving ring and sealingly engages the protruding end of the neck portion when the two rings are latched together.

BACKGROUND 
Ostomy appliances equipped with "two-piece couplings," as they are now 
commonly described, have been known for many years. For example, U.S. Pat. 
No. 3,528,420 discloses such an appliance having two deformable plastic 
rings, one of the rings 20 being secured to a faceplate 16 and the other 
ring 14 being attached to an ostomy pouch 10. A flange 26 on the inner 
ring is intended to provide an abutment for the outer ring to latch and 
seal the rings together until separation is desired. 
Other types of two-piece couplings are known, as disclosed in U.S. Pat. 
Nos. 4,419,100, 4,170,231, 4,359,051, 3,948,256, and British Pat. No. 
1,571,657. In all such constructions, latching and sealing functions are 
performed by the coupling rings themselves without the involvement or 
intervention of other elements or components. However, such sealing and 
latching functions may occur at different locations along the rings, as 
disclosed in co-pending co-owned application No. 611,423, filed May 17, 
1984. In that application, one of the rings has an axially-extending 
frusto-conical neck portion and the other ring has a frusto-conical collar 
portion detachably receiving and sealingly engaging the neck portion. 
Primary latching is achieved in an annular zone spaced a substantial 
distance radially outwardly from the area of sealing engagement between 
the neck and collar portions, such latching action being provided by a 
shoulder extending about the outer periphery of one of the rings and a 
latching ring, defining a shoulder-receiving recess, extending about the 
outer periphery of the other ring. 
SUMMARY OF THE INVENTION 
This invention lies in part in the discovery that the sealing and latching 
functions of two-piece couplings may not only occur at different locations 
but that a thin flexible web secured to one of the rings may perform an 
important function in coacting with the other ring to form a fluid-tight 
seal. In a preferred embodiment, the web may be provided by, or constitute 
an extension of, the flexible film of the collection pouch itself. 
Reinforcement of the web may also be provided to insure effective 
fluid-tight sealing action with the annular rim of the neck. The result is 
a simple, inexpensive, and highly-effective seal between the parts. 
The invention may be adapted for use with any two-piece coupling in which 
one coupling ring has a neck portion that is inserted into and protrudes 
through the opening of the other coupling ring when the two are latched 
together. The structure performing the latching function may take any of a 
variety of forms and is not critical to this invention except, of course, 
that some latching means must be provided. It is essential, however, that 
the neck portion of the first coupling ring not only extend through the 
opening of the second ring, but that such neck portion define a smooth 
annular surface that is disposed beyond the axial limits of the receiving 
(second) ring when the parts are latched together. 
The protruding annular surface of the neck portion sealingly engages an 
annular web of film joined to the backside of the receiving ring--that is, 
the side of the receiving (second) ring facing away from the first ring. 
The web of flexible, stretchable film is tensioned by the protruding 
annular surface of the neck portion and coacts with that surface to 
produce a fluid-tight (including gas-tight) seal between the parts. Such 
seal may constitute the only seal or, preferably, may be a second (but not 
necessarily secondary) seal when the coupling rings are joined together. 
In a preferred embodiment, the annular web of film is formed integrally 
with, or is sealed to, the film of the collection pouch. In such a 
construction, the coupling ring of the pouch therefore constitutes the 
receiving ring, and the faceplate coupling ring is the one provided with a 
neck portion that sealingly engages the web when the rings are latched 
together. Alternatively, the annular web may be joined to the faceplate 
ring which then serves as the receiving ring for receiving the 
web-engaging neck portion of the pouch ring when the parts are coupled. In 
any case, the flexible and stretchable web may be reinforced, or its cross 
section may be varied or contoured, to increase sealing effectiveness. 
Other features, advantages, and objects of the invention will become 
apparent from the specification and drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
FIGS. 1-3 illustrate a preferred construction in which the coupling rings 
are essentially the same as disclosed in the aforementioned co-pending 
application No. 611,423. The ostomy appliance 10 includes a faceplate 11 
and a bag or pouch 12. The two-piece coupling ring assembly 13 is provided 
for detachably coupling the faceplate and pouch, one element of the 
assembly being faceplate ring 13a and the other being pouch ring 13b. 
Typically, pouch 12 is designed to be relatively flat and is composed of 
two sheets or walls 12a and 12b of flexible transparent material with 
odor-barrier properties, such sheets being heat sealed together along 
their outer margins as indicated at 15 in the drawings. One wall 12b, 
which may be regarded as the rear wall that would face the abdomen of a 
patient when the appliance is worn, is provided near its upper end with an 
opening 16. 
Faceplate 11, in the particular form illustrated in the drawings, is 
constructed generally in accordance with the teachings of Pat. No. 
4,213,458 and reference may be had to that patent for information on the 
details of construction. Faceplate 11 includes a highly flexible patch or 
panel 17 formed of gas-penetrable but water resistant microporous 
material. Various materials having such properties are known and may be 
used. The faceplate should be highly flexible so that it will conform 
readily to body contours and body movements, and be coated on its back or 
rear side with a medical-grade pressure-sensitive adhesive so that upon 
removal of backing sheet or sheets 18 the microporous adhesive-coated 
patch or panel 17 may be secured to the patient's skin in the peristomal 
region. 
An attaching ring or collar 19 may be secured to the front face of the 
microporous patch 17 by heat sealing or by any other suitable means. In 
the illustrated embodiment, attaching ring 19 is heat sealed to the 
microporous patch along inner and outer concentric heat seal zones 20 and 
21, respectively. The attaching ring reinforces the microporous patch 17 
in the area about faceplate opening 22 and should be formed from a tough 
material capable of being securely joined to the patch. Thus, if the patch 
is formed of an ethyl vinyl acetate copolymer, the reinforcing attaching 
ring may be formed of a material of similar composition, although not 
necessarily microporous. The attaching ring must also be capable of being 
heat sealed or otherwise securely joined, either directly or indirectly, 
to ring 13a of the coupling ring assembly 13. In the construction depicted 
in the drawings, such connection is indirect to the extent that a web 23 
of thin, flexible, and resilient thermoplastic material with odor barrier 
properties is interposed between faceplate ring 13a and attaching ring 19 
of faceplate 11, as generally disclosed in co-owned Pat. No. 4,419,100. 
Specifically, the inner margin of annular web 23 is heat sealed at 20 to 
the attaching ring 19 of the faceplate 11 and its outer margin is heat 
sealed at 24 to faceplate coupling ring 13a. The web gives rise to a 
floating relationship between the faceplate ring 13a and faceplate 11, 
promoting conformity of the faceplate to a wearer's body without 
resistance from the coupling rings and, in general, allowing limited 
movement of the faceplate ring in generally axial directions with respect 
to the faceplate. Such limited movement allows a user to insert his (her) 
fingers between the ring 13a and faceplate 11 to facilitate attachment and 
detachment of the coupling rings without causing discomfort. The web 23 
should be formed of a heat-sealable, tough, and durable material that is 
also capable of functioning as a fluid and odor barrier. Low density 
polyethylene coextruded with a coextensive layer or core of polyvinylidene 
chloride, known under the designation Saranex, from Dow Chemical Company, 
Midland, Mich., has been found suitable but other materials having similar 
properties are available and may be used. 
Faceplate ring 13a has an annular body portion 25 and an integral tubular 
neck portion 26. It will be observed that the body portion 25 is planar 
and, specifically extends along a plane normal to the central axis of 
coupling ring 13a. At its outer limits, the planar body portion 25 
provides an annular latching shoulder 27 that is shown to be continuous 
although, if desired, the latching shoulder may be discontinuous or 
interrupted along its circumference. The shoulder is rounded in 
longitudinal section to facilitate latching engagement with pouch ring 
13b. 
The neck portion 26 of ring 13a is generally frusto-conical in 
configuration and tapers axially and forwardly away from body portion 25. 
The smooth frusto-conical outer surface 26a of neck portion 26 is intended 
for sealing engagement with pouch ring 13b. At its front or distal end, 
neck portion 26 has an annular and radially-outwardly projecting rim 28 
that has a rounded outer surface 28a when viewed in longitudinal section 
(FIGS. 2, 3). 
The pouch coupling ring 13b is similarly provided with a body portion 30 
that generally extends in a plane normal to the central axis of that ring. 
A generally frusto-conical collar portion 31 tapers axially from the inner 
margin of the body portion 30, the general direction of taper of collar 
portion 31 being the same as that of neck portion 26. The inner surface 
31a of the collar portion is provided with an annular projection 31b 
adjacent the free end of the collar portion, such projection defining the 
smallest inside diameter of the collar portion for sealingly engaging the 
outer surface 26a of ring 13b. The smooth rounded projection 31b 
essentially makes a line seal with surface 26a and, to help insure sealing 
effectiveness, the inner surface of collar portion 31 may be recessed at 
31c to provide greater definition for the annular projection 31b. At its 
distal or free end, collar portion 31 is provided with an axially-facing 
annular ridge 31d that normally abuts rim 28 when the parts are assembled 
as shown in FIG. 3. 
Along its outer perimeter, body portion 30 merges with an annular latching 
rib 32 which projects inwardly and axially in a direction opposite from 
that of collar portion 31 and which, along with the remainder of body 
portion 30, defines an inwardly and rearwardly facing recess 33 for 
detachably receiving and retaining the shoulder 27 of faceplate ring 13a. 
The rib may be provided with rounded surfaces to facilitate latching 
engagement and disengagement of the two rings. 
As shown most clearly in FIGS. 2 and 3, the pouch ring 13b is externally 
secured to the pouch along an annular sealing zone 34, preferably a 
heat-seal zone, that is concentric with and spaced radially outwardly from 
the opening 16 in pouch side wall 12b. It will be observed that the side 
wall opening 16 is substantially smaller than the opening 35 defined by 
the annular projection 31b of pouch ring 13b. As a result, an annular web 
of film 36 projects into the opening 35 of the pouch ring 13b. 
Since the collar portion 31 of the pouch ring 13b projects axially towards 
the pouch beyond the annular heat seal zone 34 between the pouch and pouch 
ring, and since pouch wall 12b would assume a generally planar condition 
in an untensioned state, it is believed apparent that web 36 is in a state 
of tension even when the rings are uncoupled (FIG. 2). When the neck 
portion 26 of faceplate ring 13a is urged into the opening 35 of pouch 
ring 13b, the rounded rim 28 of the faceplate ring protrudes through pouch 
ring 13b and engages web 36 (FIG. 3). Specifically, the rounded surface 
28a of rim 28 forceably and sealingly engages the web, displacing it 
forwardly into pouch 12. Since the web is in a state of tension, an 
effective fluid-tight (including gas-tight) seal occurs in the annular 
sealing zone designated by numeral 37 in FIG. 3. 
A double seal is therefore produced by the disclosed construction, one seal 
occurring between ridge 31b of the pouch ring 13b and the radially-outward 
surface 26a of faceplate ring 13a, and the other occurring between rim 28 
of the faceplate ring 13a and the extended film web 36. Increases in 
pressure within pouch 12 only force the extended film web into tighter 
sealing engagement with the rim 28 and, to the extent that the web exerts 
an axial force on rim 28, the force of sealing engagement between rim 28 
and collar portion 31 is also increased. 
In the embodiment of FIGS. 1-3, a major latching function is performed by 
latching rib 32 and latching shoulder 27. This outer latching zone is not 
a sealing zone for purposes of effectively preventing escape of fluids, 
and in fact a tight interfit between rib 32 and shoulder 27 should be 
avoided because it might interfere with completeness of sealing. The 
advantages of locating the latching zone radially outwardly from the 
sealing zone include the fact that the rings may be fabricated from softer 
and more pliable plastic materials without serious risk that deformation 
in use might result in unintentional disruption of the latching and 
sealing functions. While any of a variety of resilient and flexible 
plastic materials might be used for fabrication of the rings, low density 
polyethylene has been found particularly effective. Other tough, pliable 
materials that might be suitable are polyurethane, plasticized vinyl, and 
thermoplastic rubber. 
The embodiments of FIGS. 4 and 5 are identical to the construction already 
described except for the annular sealing webs. In FIG. 4, web 36' is not 
formed integrally with the film of pouch 12' but is instead formed of a 
different material that is heat sealed at 34' (or otherwise suitably 
sealed) to coupling ring 13b'. Most advantageously, the same heat seal 
zone 34' may join both the annular web 36' and the wall of the pouch 12' 
to coupling ring 13b'. 
As already described, the material of the annular sealing web should be 
both flexible and stretchable. The construction of FIG. 4 therefore 
permits the selection of a web material with properties better suited to 
the stretching and sealing functions than the material of the pouch 12'. 
More specifically, the web 36' may be formed of a material having greater 
elastomeric properties, less cold flow, better tensile strength, greater 
tear resistance, greater frictional properties, or different thickness, 
than the material of the pouch. In addition, the selection of a different 
material for web 36' may increase the options in the selection of material 
for pouch 12', since web 36' is interposed between the wall of the pouch 
and the coupling ring in heat seal zone 34'. Thus, a material may be 
selected for the wall of the pouch that is heat sealable to web 36' even 
though the same material is not directly or readily sealable to coupling 
ring 13b'. 
In FIG. 5, web 36" may be integral with the wall of the pouch (as in FIGS. 
1-3) or may be formed of a separate material (as in FIG. 4). A 
reinforcement 36a" is joined to web 36" at opening 16". Alternatively, the 
annular reinforcement 36a" may be integral with web 36", constituting an 
inner peripheral zone of increased thickness of the annular sealing web. 
By reinforcing or increasing the thickness of the web in the area of 
sealing contact with ring 13b", it is believed apparent that the 
effectiveness of the seal may be enhanced while at the same time retaining 
optimum flexibility and stretchability of the remainder of the web. 
FIGS. 6 and 7 illustrate how the relationship of parts might be reversed, 
with the annular sealing web 136 being secured to faceplate coupling ring 
113a rather than to pouch coupling ring 113b. The pouch ring 113b has a 
planar body portion 125 that is heat sealed at 134 to pouch 112. It also 
includes a neck portion 126 and smooth annular rim 128 that protrude 
through the opening of faceplate ring 113a when the parts are assembled. 
The latching function is performed by collar portion 131 and latching rib 
132 in essentially the same manner already described. 
The annular sealing web 136 has its outer periphery sealed to the faceplate 
ring 113a by annular heat seal zone 160 or by any other suitable sealing 
means. The thin, flexible, and stretchable web 136 is in a state of 
tension even when the parts are uncoupled because the web, which would 
assume a planar configuration in an untensioned state, must extend 
inwardly about collar portion 131 (FIG. 7). The opening 116 defined by the 
annular web 136 is substantially smaller than the opening of collar 
portion 131. At its inner limits, the web is sealed to an attaching ring 
119 which is in turn joined to adhesive-coated patch 117, the latter 
having its adhesive surface covered by release sheets 118. 
When the coupling rings are latched together, the smooth rounded surface 
128a of annular rim 128 of neck portion 126 sealingly engages web 136 as 
shown in FIG. 6. As already described, the web may be formed of any 
material having the desired properties of flexibility, stretchability, and 
durability. It is to be understood that reinforcement of web 136, as 
described in connection with the embodiment of FIG. 5, may also be 
provided. 
It is believed apparent that the latching/sealing interconnection between 
the coupling rings of all of the embodiments so far described may be 
varied considerably while at the same time retaining an effective 
fluid-tight seal between an annular web and the protruding neck portion of 
the inserted coupling ring. For example, only a single latching zone may 
be provided between the two coupling rings, and the web may engage only an 
outwardly-facing surface portion of the rim of the inserted ring, as shown 
in the modified construction represented in FIGS. 8 and 9. 
The coupling ring assembly 213 includes a faceplate ring 213a and a pouch 
ring 213b. The faceplate ring is connected to a faceplate 211 by means of 
a flexible web 223, both of which may be identical to faceplate 11 and web 
23 of the embodiment of FIGS. 1-3. It is to be understood that while the 
inclusion of webs 223 and 23 in such embodiments has important advantages 
for the user, such webs 223 and 23 may be omitted, if desired, and 
faceplate rings 213a and 13a may be joined directly by heat sealing or 
otherwise to their respective faceplates. 
Like faceplate ring 13a, the modified faceplate ring 213a includes a body 
portion 225 and a neck portion 226, the neck portion terminating in an 
enlarged annular rim 228. The rim is provided with a surface 228a which 
makes sealing engagement with the extended film web 236 of pouch wall 212b 
when the parts are coupled together as shown in FIG. 9. 
The pouch ring 213b has a body portion 230 and a collar portion 231, the 
latter defining an opening 235 which is substantially larger than the 
opening 216 of web 236. When the rings are coupled together, the end of 
collar portion 231 abuts the rearwardly-facing surface or shoulder 228b of 
the annular rim 228, thereby latching the two rings together. Some outward 
flexure of collar 231 must occur in order to accommodate the neck portion 
226 of the faceplate ring 213a with the result that a tight sealing 
engagement occurs between the inwardly-facing surface of collar portion 
231 and the outwardly-facing surface 226a of neck portion 226 (FIG. 9). 
Of particular importance is the fluid-tight seal produced by the radially 
outward displacement of web extension 236, the tensioning of that web, and 
its forceful sealing engagement against surface 228a of rim 228. 
In function and operation, the embodiment of FIGS. 8 and 9 is similar to 
the previous embodiments except that only a single latching zone is 
provided and the seal between the extended web and that portion of the 
faceplate ring that protrudes into the pouch takes place along a 
radially-outwardly facing surface 228a rather than along a 
forwardly-facing surface. Additionally, in the modified construction the 
inner limits of annular web portion 236 do not project into the opening of 
faceplate ring 213 when the rings are coupled together (FIG. 9). 
While in the foregoing, embodiments of the invention have been disclosed in 
considerable detail for purposes of illustration, it will be understood by 
those skilled in the art that many of these details may be varied without 
departing from the spirit and scope of the invention.