Pressure Relief Valve

Abstract

A cooking pot cover has an opening in which a valve body is vertically slideably and rotatably mounted. A flange on the bottom of the valve body is engageable with the cover to limit the upward movement of the valve body. A separately-formed valve cap is snap-fitted from above into the top of the valve body and is engageable with the cover to limit downward movement of the valve body. A vent opening in a cylindrical portion of the valve body is positioned to be above the cover when the valve body is in a raised position and to be below the cover when the valve body is in its lowermost position. Locking ribs project radially from the cylindrical portion of the valve body and abut against the underside of the cover to lock the valve body in its lowered position when the valve body is in a predetermined position of rotation. In another rotational position of the valve body, the locking ribs are aligned with locking recesses in the margin of the cover opening to permit upward movement of the valve body in response to steam pressure to vent the steam out of the cooking pot.

Description

BACKGROUND OF THE INVENTION

This invention relates to a pressure relief valve for cooking pots or similar utensils.

One object of this invention is to provide a manually dialable pressure relief valve for selectively venting steam from the cover of a cooking pot.

Another object of this invention is to provide a pressure relief valve of the above-described character which is simple in structure and is easy to fabricate, assemble, and operate.

Other objects, advantages, and features of the invention will be apparent to those skilled in the art from the description which follows.

SUMMARY OF THE INVENTION

A pressure relief valve body is vertically slideably and rotatably mounted in an opening in a utensil cover. Means on a lower portion of the valve body is engageable with the cover to limit upward movement of the valve body. A separately-formed valve cap is snap-fitted from above into the valve body when the body is inserted from beneath the cover. A vent opening in the valve body is positioned to be above the cover when the valve body is in a raised position and to be below the cover when the valve body is in its lowered position. Cooperating locking means on the valve body and cover selectively hold the valve body in its lowered position when the valve body is in one rotational position and permit upward movement of the valve body when it is in another rotational position to vent steam through the vent opening.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged side elevational view, partially in vertical section, of the pressure relief valve of this invention as its component parts are being assembled on a utensil cover, a fragment of the cover and utensil being shown.

FIG. 2 is a fragmentary top view of the utensil cover showing the opening therein for receiving the valve body.

FIG. 3 is a side elevational view, partially cut away, of a utensil having the pressure relief valve of FIGS. 1 and 2 installed on its cover and in venting position.

FIG. 4 is a view similar to FIG. 1 showing the valve dialed to locking position.

FIG. 5 is a top view looking in the direction indicated by the line 5--5 in FIG. 4.

FIG. 6 is an enlarged top view of the valve body alone before the valve cap is attached thereto.

FIG. 7 is a cross-sectional view taken on the line 7--7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The drawing shows one embodiment of the invention which is mounted in an opening 10 (FIG. 2) in the cover 12 (FIG. 3) of a cooking pot 14. This embodiment includes a valve body 16 and a valve cap 18 which are snap-fitted together by means described hereinafter. Valve body 16 is shaped in the form of a cylindrical sleeve having an outer diameter which is slightly smaller than the opening 10 so that valve body 16 will be vertically slideable and rotatable therein. Two vertical locking ribs 20 (FIGS. 4 and 6) are formed on the outside of the cylindrical portion of the valve body 16. Locking ribs 20 are semi-cylindrical in cross section, and are positioned diametrically opposite each other on the valve body 16. A cooperating pair of semi-circular recesses 22 (FIG. 2) is formed in diametrically-opposite locations in the margin of opening 10 to receive the locking ribs 20 when the valve body 16 is in one position of rotation (the position of FIG. 3). Thus the valve body 16 is movable up and down in opening 10 when the locking ribs 20 are aligned with recesses 22. However, in all other rotational positions of valve body 16, the upper ends 24 of ribs 20 (FIGS. 4 and 7) abut against the underside of the utensil cover 12 and prevent the valve body 16 from moving upwardly.

One or more vent openings 26 (FIGS. 3 and 7) are formed in valve body 16 in such position as to be above the cover 12 when the valve body 16 is in a raised position, as shown in FIG. 3, but to be below cover 12 when the valve body 16 is in its lowered position. Thus, when valve body 16 is in the dialed position of FIGS. 1 and 3 in which locking ribs 20 are aligned with recesses 22, steam pressure in pot 14 will enter the interior of the cylindrical body 16 to push the valve body upwardly until vents 26 are above cover 12, thereby allowing the steam to escape from pot 14 through the vents 26 and thus relieve the pressure within pot 14. Upward movement of the valve body 16 is limited by a flange 28 (FIG. 4) which is formed at the bottom of valve body 16 and which projects outwardly therefrom so as to engage the under surface of the cover 12. When the valve body 16 is dialed to a rotational position such as that of FIGS. 4 and 5 in which the locking ribs 20 are not aligned with the recesses 22, the upper ends 24 of ribs 20 abut against the underside of the cover 12 inwardly of the margin of the opening 10 to lock the valve body 16 in closed position where steam is confined within the pot.

One important feature of this invention is that the valve body 16 and the valve cap 18 can be easily assembled by simply snap-fitting the two parts together. As a means of snap-fitting the valve cap 18 and valve body 16 together, the top of the valve body has an opening 30 with an inwardly-tapering and rounded margin 32. The opening 30 is dimensioned to yieldingly receive a cylindrical stem 34 having a conically-tapered lower portion 36 providing a shoulder 38 which is positioned so that it can be snapped beneath the margin of the opening 30 to lock the cap 18 to the body member 16 (see FIG. 1). This is accomplished by the simple expedient of pressing the two parts together with the body 16 positioned beneath the pot cover 12 and the cap 18 inserted from above the cover.

Cap 18 has a raised, tapered finger hold 40 (FIGS. 1 and 5) on its upper surface to allow the cap 18 to be easily grasped for dialing. The front end of the finger grip 40 is pointed at 42 to form an indicator to show the orientation of the locking ribs 20. To insure that the pointer 42 is aligned in assembly with the locking ribs 20, a pair of guide openings 44 (FIG. 6) are formed on the upper surface of valve body 16 and are positioned to receive matching guide bosses 46 (FIG. 1) when the valve cap 18 is press-fitted onto the valve body 16.

The valve cap 18 and valve body 16 can be conveniently molded from a suitable plastic material such as is available under the trade name of "Zytel," or any other suitable plastic material such as nylon. This type of material has sufficient resiliency to provide for the snap-fit during assembly when the conical portion 36 of stem 34 is snapped from the full line position of FIG. 1 to the dotted line assembled position. It will be apparent to those skilled in the art that the valve cap 18 and valve body 16 can be mass produced at a very low cost by injection molding or similar processes. Also, the opening 10 and semi-circular recesses 22 can be easily made in the cover 12 at a very low cost.

In use of a cooking pot equipped with the improved pressure relief valve, if the housewife is cooking something in the pot in such a manner that there will be a pressure build-up, she merely dials the valve to the position shown in FIGS. 1 and 3 where the ribs 20 are aligned with the recesses 22. Then, as soon as pressure builds up, the steam will act against the valve to move it to the elevated position of FIG. 3. This brings the vents 26 above the surface of the cover and allows the steam to freely escape. If, on the other hand, the housewife is cooking vegetables or other food on a low flame where excessive pressure build-up is not likely to occur, then the valve can be dialed to the position of FIGS. 4 and 5 to lock the valve in the lowered position. This precludes the escape of steam from the valve but will speed up the cooking process and improve the results for certain types of food items. Of course, even when the valve is locked as in FIGS. 4 and 5, with the type of cooking pot and cover illustrated, the cover can, of course, bobble up and down to relieve excessive steam pressure, should this occur. For most operations this is undesirable and, by having the valve dialed to the position of FIGS. 1 and 3, pressure is relieved without the objectionable bobbling of the cover which would otherwise occur. The present relief valve enables the housewife to select the type of steam control best suited for the item being cooked.

Various changes and modifications may be made without departing from the spirit of the invention, and all of such changes are contemplated as may come within the scope of the claims.

Claims

What I claim is:

1. In combination with a utensil cover having an opening therein, a pressure relief valve body vertically slideably and rotatably mounted within said opening; means on a lower portion of said valve body engageable with said cover to limit the upward movement of said valve body; a separately-formed valve cap for said valve body, said cap having means engageable with the top of the cover to limit the downward movement of the valve body; cooperating means on said cap and valve body connecting the same in assembled relationship while aligned with the cover opening and with the cover between at least a portion of said valve body and cap, said valve body having a vent opening positioned to be above said cover when said valve body is in a raised position and positioned to be below said cover when said valve body is in its lowered position; and cooperating locking means on said valve body and cover to selectively lock said valve body in its lowered position when the valve body is in one position of rotation and to permit upward movement when the valve body is in another position of rotation.

2. The combination claimed in claim 1 wherein said means on the bottom of said valve body engageable with said cover to limit the upward movement of said valve body comprises an outwardly-extending flange at the lower end of said valve body, said flange extending far enough outwardly from said valve body so that it will abut against the bottom of said cover when the valve body is in a raised position.

3. The combination claimed in claim 1 wherein said cooperating means on said cap and valve body for connecting the same in assembled relationship comprises an opening in the top of said valve body having an inwardly-tapered marginal portion, a stem projecting downwardly from said valve cap and having a conically-tapered lower portion providing a shoulder, there being relative resiliency between said tapered stem portion and the marginal portion of the opening, and said tapered portion and shoulder of said stem being positioned and sized to snap through said tapered marginal portion of said opening in response to pressure.

4. The combination claimed in claim 1 wherein said cooperating locking means on said valve body and cover comprises at least one locking rib projecting radially outwardly from said valve body, and at least one cooperating recess in the margin of said cover opening, said recess being large enough to receive said locking rib when the rib is aligned with said recess to permit upward movement of the valve member to venting position, and the upper end of said locking rib being located adjacent the lower surface of said cover when said locking rib is out of alignment with said recess to lock the valve body in non-venting position.

5. The combination claimed in claim 4 and further comprising a pointer on said valve so positioned relative to said locking rib as to indicate the position thereof with respect to said recesses in the margin of said cover opening.

6. The combination claimed in claim 1 and further comprising guide means projecting downwardly from said valve cap and engageable with matching guide means in the upper end of said valve body for insuring proper rotational orientation between the valve cap and valve body when the two parts are assembled.

7. The combination claimed in claim 1 in which said valve body is a cylindrical sleeve having an outwardly-projecting annular flange at the lower end thereof and having a top opening, the inner margin of said opening being tapered, and further comprising a tapered stem projecting from the bottom of said valve cap dimensioned to interact with said tapered margin to provide for snap-fitting the two parts together.