Seal with vent

A vent assembly for the seal of a food container including a vent opening in the seal panel at least partially surrounded by an upperwardly opening recess with the vent opening and recess being below the plane of the upper face of the panel. A vent cover pivotally mounts to the seal and, when selectively closed over the vent hole, partially overlies the recess to allow for engagement of fingers with the cover in the recess for upwardly opening of the cover. The closed cover does not project above the plane of the top panel of the seal as to interrupt the planar nature thereof.

BACKGROUND OF THE INVENTION 
Food storage containers, conventionally of an appropriate plastic or 
synthetic resinous material such as polypropylene, are frequently also 
used as convenient containers for the heating or reheating of foodstuffs 
within a microwave oven. However, in order to accommodate the buildup of 
internal pressures during heating, the seal of the container must be 
removed or at least partially released. Complete removal of the seal is 
often not desirable because of potential spillage problems, an exposure of 
other goods within the oven to fumes emitted from the container stored 
goods, and the like. 
Similarly, a partial opening of the seal, normally by an upward stripping 
of one section of the frictionally engaged edge flange, is inexact, 
particularly when dealing with round containers and seals, and could lead 
to an accidental release of the entire seal as a result of internal 
pressures. 
SUMMARY OF THE INVENTION 
The present invention comprises a seal for use with a storage and/or 
microwave heating container which incorporates a separate covered vent. 
The vent is selectively openable without disruption of the seal, that is 
without requiring partial release or removal of the seal. 
The vent is integrally formed within the top panel of the seal and so 
oriented as to provide no projection or raised interruption in the planar 
upper face of the seal panel. This is of significance in that storage 
containers of the general type herein involved are conventionally stacked, 
one upon the other, thereby requiring substantially planar upper and lower 
stacking faces. 
The vent cover, notwithstanding the flush positioning thereof when closed, 
is easily grasped and opened, even by the infirm or elderly. In addition, 
to facilitate cleaning, the cover, including the hinge assembly thereof, 
is removable from and remountable to the seal. 
Structurally, the vent assembly is incorporated in the planar top panel of 
the seal, adjacent the peripheral flanged edge thereof. The vent assembly 
includes an annular depression in the seal panel inward relative to the 
outer or top face thereof and surrounding a central vent hole defined at 
the upper end of a truncated generally conical stem at a height slightly 
below the outer top face of the seal panel. 
The vent cover is generally planar and includes an integral depending 
sealing plug selectively snap-locked within the vent opening for a sealing 
thereof. The cover, in the closed sealing position thereof, presents an 
upper surface substantially coplanar with the outer face of the seal 
panel, or sufficiently close thereto as to provide a flat stacking face. 
The cover is integrally joined, by a living hinge, to an elongate mounting 
bar having a pair of depending headed lugs which snap-lock into sockets or 
hollow pedestals formed integral with a portion of the wall of the 
upwardly directed depression or recess. The cover, so mounted, will, upon 
manual manipulation, pivotally or hingedly move between open and close 
positions. 
The cover projects beyond the sealing plug sufficient so as to extend 
slightly beyond the conical stem, the upper end of which defines the vent 
opening. This projecting portion slightly overlies the recess both forward 
and to the opposed sides of the cover, relative to the mounting bar. In 
this manner, and notwithstanding the planar relationship between the cover 
and the top panel of the seal, the cover can be easily grasped for manual 
manipulation. Basically, one need merely extend the fingers of one hand in 
the recess to underlie the projecting periphery of the cover and exert an 
upward pull thereon for a snap-disengagement. It is contemplated that the 
upwardly directed recess be such as to accommodate several fingers well 
below the cover, thus making manipulation of the cover easy for even the 
infirm. As an example, the finger accommodating portion of the annular 
recess, which will extend about a major portion of the cover other than 
for the hinged mounted portion thereof, can have an arcuate cross-section 
with a radius of approximately 1.085 cm drawn from a midpoint at or 
slightly below the lip portion of the vent opening. This in turn will 
result in a recess depth of approximately 1.085 cm, and a transverse 
recess width, at the upper portion thereof, of approximately 2.17 cm. 
These dimensions may vary, and are presented as representative to clearly 
illustrate that the recess is such as to accommodate a substantial tip 
portion of the manipulation fingers.

DESCRIPTION OF PREFERRED EMBODIMENT 
Referring now more specifically to the drawings, FIG. 1 illustrates a 
storage container 10 with the vented seal 12 of the invention mounted 
thereon. Both of these units, including the various components of the seal 
12 and vent, are of appropriate food-compatible and microwavable plastic 
or synthetic resinous material, for example high crystalline 
polypropylene. 
The peripheral configuration of the seal 12 will be compatible to the shape 
of the mouth of the particular bowl 10 to which it is associate. For 
purposes of illustration, the seal 12 has been illustrated as circular, 
the bowl 10 being of a rather conventional rounded configuration. 
The seal 12, as is generally conventional, includes a container-covering 
top panel 14 surrounded by an integral mounting flange 16. The panel 14 
has an upper or outer face 18 which is preferably planar or substantially 
planar to allow for a stacking of multiple storage containers, and a 
similar planar or substantially planar under or inner face 20. 
The peripheral mounting flange 16, preferably slightly upwardly offset from 
the upper face 18 of the panel 14, defines a downwardly directed groove 22 
annularly about the seal 12 and adapted to releasably snap-lock to the 
upper rim of the bowl 10 in an obvious manner. 
As the container is specifically intended for use in the heating or 
reheating of foodstuff in a microwave oven or the like, the seal 12, as a 
principal feature of the invention, is provided with a vent assembly 24. 
The vent assembly 24 comprises an upwardly opening annular depression or 
recess 26 formed in the panel 14 preferably adjacent the peripheral 
mounting flange 16. The recess is formed entirely below the planar upper 
or outer face 18 of the panel 14 and, in traverse cross-section, presents 
a substantially semicircular configuration. This in turn, as noted in FIG. 
5, provides a generally toroidal appearance when viewed from the under 
face of the panel 14. 
The annular recess 26 defines a central substantially conical upwardly 
directed hollow stem 28. The stem terminates in a truncated upper end 
defining a vent opening or hole 30 which provides for direct communication 
through the seal panel 14. The upper end of the stem 28, whereat the 
opening 30 is defined, is offset inwardly or below the plane of the upper 
face 18 of the panel 14 for reasons to be explained subsequently. Further, 
the inner surface of the upper end portion of the stem 28, about the 
defined opening, includes a slight peripheral undercut area or notch 32 
therein. 
In order to selectively close and seal the vent opening or hole 30, for 
example when a venting of the interior of the container is not necessary 
such as during use as a storage container, the vent assembly 24 is 
provided with a vent cover 34. The vent cover 34 comprises a generally 
circular panel 36 with an integrally formed depending or inwardly directed 
plug 38. The plug 38 is of a size for snug frictional reception within the 
vent opening 30 for an effective closing of the vent and a sealing of the 
vent assembly. In order to releasably secure the plug 38 within the 
opening 30, provision is made for a releasible snap-locking engagement by 
means of an annular integral bead 40 formed about the plug 38 in slightly 
spaced relation below the cover panel 36 for engagement within the notch 
32 simultaneously with a seating of the cover panel 36 on the upper rim of 
the stem 28 about the opening 30, as best illustrated in the sectional 
detail of FIG. 3. With continued reference to FIG. 3, it will be 
appreciated that with the vent cover 34 closed, the upper surface of the 
cover panel 36 is substantially coplanar with the upper or outer face 18 
of the seal panel 14, thus maintaining a planar stacking surface without 
any disruptive projection within the peripheral mounting flange 16. 
Basically, the thickness of the panel 36 of the cover 34 is equal or 
slightly less than the vertical spacing of the upper end of the vent stem 
28 below the upper face 18 of the seal panel 14. 
The cover panel 36 is, in the illustrated embodiment, substantially 
circular with the plug 38 positioned eccentric, that is in more closely 
spaced relation to one portion of the periphery or circumference. 
Diametrically opposed therefrom, and along a cord perpendicular to this 
diameter, the cover panel 36 is integrally joined to an elongate mounting 
bar 42 by a living hinge 44. 
The mounting bar 42 includes a pair of spaced integral shoulder portions 
46, each having an elongate projecting integral mounting lug 48 thereon. 
Each lug 48 is in turn formed with an enlarged tapered head or leading end 
50. 
In order to accommodate the mounting bar 42 and lugs 48, a pair of hollow 
upwardly opening pedestals 54 are integrally formed with and project 
radially inward from the peripheral wall of the recess 26 at a spacing 
corresponding to the spacing of the mounting bar lugs 48. These pedestals 
54 define upwardly opening sockets with planar upper surfaces 56 
surrounding the lug-receiving apertures 58. 
Noting FIGS. 3 and 4 in particular, the lugs 48 engage through the 
corresponding pedestal openings 58 with the enlarged headed ends 50 
thereof locking within the sockets as the mounting bar shoulders 46 seat 
on the respective upper surfaces of the respective pedestals 54. The 
inherent resiliency of the material of the pedestals and lugs, and the 
tapered configuration of the lug heads 50, allow for snap-mounting. 
Similarly, for cleaning or replacement purposes, the lugs, upon 
application of appropriate pressure, can be withdrawn. As illustrated, the 
pedestals 54 open downwardly or inwardly as a molding expedient. However, 
as desired, the pedestal sockets can be formed with closed inner ends. 
The cover panel 36, forwardly from the opposed ends of the living hinge 44, 
projects sufficiently beyond the plug 38 as to partially overlay the 
recess 26 radially outward of the vent stem 28. The overlaying of the 
recess generally diametrically opposed from the living hinge 44 provides 
for a gripping lip, enhanced by a peripheral bead 60, sufficient as to 
allow for positive manual engagement by one or more fingers of a user for 
an upwardly opening of the cover 34. As will be appreciated from FIGS. 1 
and 2 in particular, this peripheral extension of the cover panel 36 
progressively increases rearwardly toward the living hinge. However, at 
least a major portion of the recess 26 forward of the living hinge 44 is 
readily accessible for at least one and possibly as much as four fingers, 
thus providing for positive engagement with the cover and substantial 
leverage to disengage the plug and upwardly pivot the cover to open the 
vent. 
While the recess 26 has been defined as symmetrical about the central stem 
28, interrupted only by the pedestals 54, obvious variations are also 
contemplated. For example, the centrally formed stem 28 can be offset 
closer toward the pedestals 54, thus in effect providing a relatively 
wider finger-accommodating recess area toward the forward side of the 
cover opposed from the hinge. Such a variation might also involve a more 
central positioning of the cover plug 38 on the cover panel 36. 
Other possible variations of the preferred illustrated embodiment may 
include recesses of other than annular configuration. However, in each 
instance, the recess will extend peripherally along or about a substantial 
or major portion of the periphery of the cover and be of a width and depth 
sufficient to accommodate multiple fingers in underlying relation to the 
extending peripheral edge of the cover panel. In addition, in each 
variation the cover, in the closed position thereon, is to be 
substantially in or slightly below the plane of the top panel of the seal 
to maintain the planar stacking surface thereof. 
The vent assembly of the invention provides a unique means for venting or 
providing a steam and pressure release for food containers when used in a 
microwave oven. In this manner, the versatility of a standard food 
container can be substantially enhanced, while at the same time retaining 
all of the desirable features of the conventional storage container, 
including a complete sealing thereof, an ability to stack the containers, 
and the retained ability to open and close the containers in the 
conventional manner. 
The foregoing is illustrative of the features of the invention. As 
indicated, other embodiments incorporating such features may occur to 
those skilled in the art, and should be considered as within the scope of 
the invention more particularly defined in the claims following 
hereinafter.