Title of Invention

A SYSTEM PRESSURE RELEASE DEVICE FOR A PRESSURE COOKER

Abstract

ABSTRACT A steam pressure release device for a pressure cooker, for insertion into an aperture in the lid of the cooker, comprises a tubular portion terminating at one end in a hollow collar, the circumference of the tubular portion being smaller than that of the aperture and the circumference of the collar being larger than that of the aperture. The mouth at the base of the hollow collar is closed by a fusible plug. A sealing ring is provided around the tubular portion at the junction of the tubular portion and the collar, said ring having a circumference larger than that of the aperture, but smaller than or substantially the same as that of the collar. The tubular portion, up to the other end thereof, is provided with through-slits on its side, the through-slits terminating in a contoured flared head having a circumference just larger than that of the aperture.

Full Text

This invention relates to a steam pressure release device for a pressure cooker. An objective of the device proposed herein is to close an aperture in the lid of the pressure cooker under increasing steam pressure build—up, at the start of the cooking operation; to release steam, even after full steam pressure build-up, whenever the user wishes to open the lid. The user is enabled to let out the steam in a one-shot operation or in stages, as desired, before opening the lid. The device proposed herein also has a provision to let out steam in a one-shot operation, in the event of excessive build-up of pressure. This may happen, for instance, when the pressure release weight valve of the cooker malfunctions. The device proposed herein is simple in its construction, yet quick and efficient in operation, as will be clear from the following further description thereof given hereunder. Various other advantageous features of this invention will also be apparent from such description. According to this invention, the steam pressure release device for a pressure cooker, for insertion into an aperture in the lid of the cooker, comprises a tubular portion terminating at one end in a hollow collar, the circumference of the tubular portion being smaller than that of the aperture and the circumference of the collar being larger than that of the aperture, the mouth at the base of the hollow collar being closed by a fusible plug; a sealing ring provided around the tubular portion at the junction of the tubular portion and the collar, said ring having a circumference larger than that of the aperture, but smaller than or substantially the same as that of the collar, said tubular portion, up to the other end thereof, being provided with through-slits on its side, the through-slits terminating in a contoured flared head having a circumference just larger than that of the aperture. Means are provided for use with the said device for depressing the flared head. The device proposed herein will now be described in greater detail by referring to the accompanying drawings which illustrate, by way of example, and not by way of limitation, one of various possible embodiments of this invention, wherein Figs.lA and IB illustrate the said embodiment Fig.2 illustrates the said embodiment located in the aperture of the lid of a pressure cooker, closing the aperture fully and Fig.3 illustrates the said embodiment located in the aperture of the lid of the cooker, opening the aperture. The device is intended for insertion into an aperture A in the lid L of a pressure cooker. The insertion is effected from the underside of the lid L. The device comprises a tubular portion T. At one end, the said tubular portion terminates in a hollow collar C, the circumference of which is larger than that of the aperture A. The circumference of the tubular portion T is however smaller than that of the aperture A. As already stated, the collar C is hollow; however, the mouth of the hollow at the base of the collar is closed by a fusible plug P made of a material such as tin-bismuth alloy. This plug would fuse (melt) under excessive steam pressure in the bowl of the pressure cooker, corresponding to a predetermined temperature, and thus open the said mouth to release steam from the bowl, in a one-shot operation. The steam escapes through the hollow of the collar, passes through the tubular portion T and around it and thence to atmosphere, to relieve the bowl of such pressure. Such a situation of build-up of excessive pressure would arise when the pressure release weight valve, with which a pressure cooker is normally equipped, fails to function. A sealing ring S is provided around the tubular portion T at the junction J thereof and the collar C. The circumference of the sealing ring S is larger than that of the aperture A, but smaller than or substantially the same as that of the collar C. The tubular portion T is provided with through-slits Y on its sides terminating at the other end thereof in a flared head F of circumference just larger than that of the aperture A. The flared head F is contoured at Z, to furnish an outward bulge. To install the device, the flared head F is pushed into the aperture A from the underside of the lid L. Although the flared head F has a larger circumference than that of the aperture A, the through-slits on the flared head F and the contour (outward bulge) at Z of the said head permit the said head F to contract, under resilience, when thrust against the aperture A, to reduce itself in circumference and enter the aperture A. Once the flared head F passes through the aperture A, it resumes its normal circumference, which is larger than that of the aperture A, thus preventing itself from coming out of the aperture A, unless forcefully tugged out of the aperture. With the device inserted into the aperture A in the lid, as aforesaid, and with the lid L closed over the bowl of the pressure cooker, the steam, initially generated within the bowl, passes through the aperture A to atmosphere inasmuch as the collar C and sealing ring S dangle from the aperture A and therefore do not fully close the said aperture. Further build-up of steam within the bowl causes the collar C and sealing ring S to urge themselves against the aperture A and fully close it, thus allowing normal steam pressure build-up to take place within the bowl. Whenever the pressure cooker is in use, the user can release steam pressure from the bowl by depressing the flared head F, even under conditions of full steam pressure build-up in the bowl. Depression of the flared head F causes the collar C to descend into the bowl, opening the aperture A in the lid, permitting steam from the bowl to enter the aperture A, pass through, and around, the tubular portion T and thence to atmosphere. It is preferred to have the flared head F accommodated within the top handle of the pressure cooker, with a hole provided in the handle, for allowing escaping steam to emerge through the said hole, to atmosphere. To a substantial extent this would identify the escape route of steam and minimise the possibility of the user being inadvertently scalded. Additionally, the handle in which the flared head would be accommodated would serve to shield the user from the said device. In the preferred arrangement wherein the flared head F is accommodated within the top handle of the pressure cooker, depression of the head F is conveniently achieved by means of a lever. The flared head can either be continuously depressed until all the steam pressure within the bowl is depleted or the said head F can be depressed in stages to reduce the steam pressure in intervals. Conventionally, whenever the user intends to open the lid of the pressure cooker, when there is already steam pressure build-up in the bowl, a crude makeshift instrument, such as a knife or a screwdriver, is made use of to lift the weight valve. Frequently, the weight is sought to be lifted by hand using a piece of cloth to grip the hot top end of the weight. These crude methods are eliminated by the device proposed herein. The terms and expressions in this specification are of description and not of limitation, as such terms and expressions do not excliide any equivalents of the features illustrate and described, but various other embodiments of this invention are possible without departing from the scope and ambit thereof We Claim: 1. A steam pressure release device for a pressure cooker, for insertion into an aperture in the lid of the cooker, comprising a tubular portion terminating at one end in a hollow collar, the circumference of the tubular portion being smaller than that of the aperture and the circumference of the collar being larger than that of the aperture, the mouth at the base of the hollow collar being closed by a fusible plug; a sealing ring provided around the tubular portion at the junction of the tubule portion and the collar-, said ring having a circumference larger than that of the aperture, but smaller than or substmitially the same as that of the collar, said tubular portion, up to the other end thereof, being provided with through-slits on its side, the through-slits terminating in a contoured flared head having a circumference just larger than that of the aperture. 2. A steam pressure release device for a pressure cooker substantially as herein described and illustrated in the accompanying drawings.

Documents:

0557-mas-2001 abstract duplicate.pdf

0557-mas-2001 abstract.pdf

0557-mas-2001 claims duplicate.pdf

0557-mas-2001 claims.pdf

0557-mas-2001 correspondence others.pdf

0557-mas-2001 correspondence po.pdf

0557-mas-2001 description (complete) duplicate.pdf

0557-mas-2001 description (complete).pdf

0557-mas-2001 drawings duplicate.pdf

0557-mas-2001 drawings.pdf

0557-mas-2001 form-1.pdf

0557-mas-2001 form-19.pdf

0557-mas-2001 form-26.pdf