Title of Invention

A DEAD WEIGHT PRESSURE REGULATOR SYSTEM FOR A PRESSURE COOKER

Abstract

A DEAD WEIGHT PRESSURE REGULATOR SYSTEM FOR A PRESSURE COOKER COMPRISING A DEAD WEIGHT PROVIDED WITH A LIFTING KNOB AND A VALVE PIN, A VALVA STEM WITH AN ORIFICE NORMALLY CLOSED BY THE VALVE STEM TAPERINGT OUTWARDS,CHARACTERISED BY A GROOVE,IN THE DEAD WEIGHT BODY,SURROUDING THE VALVE STEM BELOW THE TAPERED PERIPHERY;AND AN O-RING MADE OUT OF AN ELASTOMER,SNUGLY SEATED IN THE GROOVE BUT PROTRUDING SIDEWARDS,OUT OF THE GROOVE,TO BUTT AGAINST THE TAPERED PERIPHERY,WHENEVER THE DEAD WEIGHT LIFTS UNDER THE PRESSURE OF STEAM WITHIN THE SAID COOKER.

Full Text

This invention relates to a dead weight pressure regulator system for a pressure cooker. The term "pressure cooker" in this specification not only means a pressure cooker commonly known as such, but also other pressure vessels (autoclaves) wherein steam is generated and retained under pressure. The dead weight pressure regulator system proposed herein is self-contained so that it can be mounted on a pressure vessel, such as, a pressure cooker to maintain the internal pressure of the said vessel at a value predetermined by the dead weight of the said system. Dead weight pressure regulator systems are known to the art. In the known system, the upward movement of the dead weight, when steam pressure acts on it, is limited by pins and a split ring, the said pins restricting the upward movement of the dead weight to a predetermined limit. The above known arrangement has its drawbacks; The pins get worn out soon as a result of the frequent movement of the dead weight while letting out steam and the equally frequent contact between the pins and the valve stem. Variation in operation of the pins takes place resulting from variation in the dimensions and strength of the pins. Since the pins are metallic and thus not flexible, the manual force required for withdrawing the dead weight from its seating and inserting it back into place, ultimately causes damage to the pins and the metallic valve stem, due to the frequent metal to metal contact between the pins and the valve stem, leading to the malfunctioning of the system. Accordingly this invention proposes a dead weight pressure regulator system by which the above mentioned drawbacks associated with the known system are obviated, resulting in an efficient, durable and smooth functioning device. The various features and advantages of the dead weight pressure regulator system, not hereinbefore explicitly set forth will be apparent from the following further description. The dead weight pressure regulator system for a pressure cooker, according to this invention, comprises a dead weight provided with a lifting knob and a valve pin; a valve stem with an orifice normally closed by the valve pin, a portion of the external periphery of the valve stem tapering outwards, characterised by a groove in the dead weight body surrounding the valve stem below the tapered periphery; and an O-ring, made out of an elastomer, appropriately seated in the groove but protruding sidewards, out of the groove, to butt against the tapered periphery, whenever the dead weight lifts under the pressure of steam within the said cooker. This invention will now be described with reference to the accompanying drawings which illustrate, by way of example, and not by way of limitation, one of various possible embodiments of the dead weight pressure regulator system proposed herein, Fig.l illustrating the external view of the embodiment And Fig.2 illustrating a sectional view of the said embodiment. The embodiment has a dead weight 14, the sleeve of which is indicated by 4. A lifting knob 7 enables the assembly to be manually lifted and replaced in position. A valve pin 6 of the dead weight normally closes an orifice 9 of the valve stem 3 whenever the dead weight is in place. The orifice 9 communicates with the interior of the pressure cooker, so that as long as the steam pressure inside the cooker is at or below a predetermined limit, the valve pin keeps the orifice 9 closed, but when the pressure exceeds the limit, such pressure forces the valve pin 6 to lift the dead weight 14, thus opening the orifice 9 and allowing the steam to escape, until the pressure reduces to allow the dead weight 14 to revert to its normal position and thus cause the valve pin 6 to close the orifice 9 once again. The escape of steam takes place through the vents 10. A cowl S acts as a shield for preventing the escaping Bteam from scalding the user. As already explained in the known dead weight pressure regulator system, the upward movement of the dead weight under steam pressure above the predetermined limit is restricted by pins against which the butts whenimoved ° upwards by the steam Furthermore, whenever the dead weight is to be manually removed and replaced from time to time, it is only by a sliding friction contact between the and the valve stem that this can be achieved. As explained above this results in wear and tear of the pins, leading to malfunctioning of the system. This invention, however, is characterized by a groove 12 which surrounds the valve stem 3 below the taper 13; and an O-ring 2 made out of an elastomer, snugly seated in the groove but protruding sideward, out of the groove. Thus, whenever there is a pressure build-up inside the pressure cooker, above a predetermined limit, steam in the valve stem 3, acting on the valve pin 6. lifts the dead weight 14. While doing so the O-ring comes into contact with, thus butting against, the tapered portion 13 and halts the further upward travel of the dead weight 14. On the steam now escaping through the vents 10, the pressure reduces to a value below the predetermined limit, and the dead weight 14 reverts to its normal position. It will thus be observed that the contact between the O-ring 2 and the tapered portion 13 eliminates the harsh metal to metal contact of the known pressure regulator system; that the manual removal of the dead weight 14 and replacement thereof in position is smooth and effective. The terms and expressions in this specification are of description and not of limitation, inasmuch as various other embodiments of this invention are possible without departing from the scope and ambit thereof. We Claim: 1 .A dead weight pressure regulator system for a pressure cooker comprising a dead weight provided with a lifting knob and a valve pin; a valve stem with an orifice normally closed by the valve pin, a portion of the external periphery of the valve stem tapering outwards, characterised by a groove, in the dead weight body, surrounding the valve stem below the tapered periphery; and an O-ring, made out of an elastomer, snugly seated in the groove but protruding sidewards, out of the groove, to butt against the tapered periphery, whenever the dead weight lifts under the pressure of steam within the said cooker. 2.A dead weight pressure regulator system as claimed in Claim 1 wherein the O-ring is made of an elastomer capable of withstanding the continuous working temperature of steam. 3. A dead weight pressure regulator system as claimed in Claim 1 or Claim 2 wherein the O-ring is made out of nitrile rubber, silicone rubber, fluoro elastomer, chloro sulfonated polyethylene. 4. A dead weight pressure regulator system substantially as herein described and illustrated with reference to the accompanying drawings.

Documents:

903-che-2004-claims duplicate.pdf

903-che-2004-claims original.pdf

903-che-2004-correspondnece-others.pdf

903-che-2004-correspondnece-po.pdf

903-che-2004-description(complete) duplicate.pdf

903-che-2004-description(complete) original.pdf

903-che-2004-drawings.pdf

903-che-2004-form 1.pdf

903-che-2004-form 19.pdf

903-che-2004-form 26.pdf