Title of Invention

A COOKER WITH A SIGNALING DEVICE INDICATING THE STAGE OF COOKING

Abstract

This invention provides a cooker with a signaling device indicating the stage of cooking comprising a vessel and a whistle, said whistle having a whistle body housing a cavity communicating with the mouth of the whistle through a narrow orifice and with the exterior through another opening situated on the wall of the whistle body, characterizes in that a small container is provided in connection with the said vessel, said small container extending to the bottom of the vessel, and means provided for fitting said whistle on to the said small container with the mouth of the whistle opening to the interior of the small container and its external opening communicating with the exterior in the fitted position of the cooker.

Full Text

This invention relates to a cooker with a signaling device indicating the stage of cooking. The housewife who keeps an ordinary vessel filled the cooking medium on the stove has so far no efficient and economical signaling means which would indicate that the contents have been brought to boil and that the cooking has progressed to a certain extent or is continuing satisfactorily or has been completed. There are occasions when the housewife who has gone for some other work has forgotten that the cooker had even been placed on the stove. She is therefore required to stand by the stove till the cooking has been completed. The need is often felt for a simple and economical signaling device that would give out a signal that has some correlation vetch the stage of cooking in the cooker. Even a signal that warns the operator some time after the cooking medium has been brought to boil would be valuable, as most Indian foods require boiling for some time. An indicator that tells a few minutes before or almost at the same time as the boiling of the cooking medium is however the desirable one. But any signaling device that gives out a signal indicating that the cooker is remaining on the stove and is being heated will have some value for the busy housewife. Pressure cookers usually produce a hissing sound at their safety valve and therefore generally do not require an indicator. A survey of the prior art shows that: 1. Milk cookers with whistling devices fitted on an outer water jacket (Indian Patent No. 114635) are available. The defect of these double walled milk cookers is that the milk is seldom brought to boil (it can boil only after all the water has been evaporated and then very inefficiently by heat transmission through the air space between the inner and outer walls at the bottom of the cooker). Most people do not wait for the real boiling of the milk and take out the cooker from the stove after hearing the whistle for some time. As such the milk is routinely heated only to 100 degrees C and seldom reaches its boiling point and the harmful bacteria are not fully destroyed. The need is therefore felt for a milk cooker that allows milk to boil fast while giving the necessary warning signal. 2. Rice and 'idli' cookers comprising a single walled wide mouthed vessel fitted with a lid provided with a rubber gasket for ensuring a leak proof seal, said lid being held down by clips or buckles, the vessel being provided with a whistle are well known in the prior art. The gasket and the clips add to the inconvenience of this cooker. The absolute necessity of the lid hinders such operations as stirring and checking of the contents at frequent intervals. In some 'idly' cookers not provided with a gasket and clips, leakage at the wide mouth of the cooker is a frequent occurrence and the powerful gush of steam required to energize the whistle is occasionally not obtained. Ideally the vessel containing the water required for energizing the whistle should be a closed chamber open only at its narrow neck for fitting the whistle as is done for the currently available double walled milk cookers. 3. Hospital sterilizers and electric kettles for household use are not currently being provided with efficient non-mechanical warning devices that indicate that the contents have been brought to boil. This occasionally results in the heating element burning out by dry heating once all the water has been evaporated. Fitting a whistle on the lid of an electric kettle (having a pour spout) would not produce a whistling sound, as the steam would leak out through its open pour spout. A whistle suitably attached to kettles and sterilizers would not only signal the onset of boiling but would also indicate the commencement of dry heating by the cessation of the whistle. The object of this invention is to propose an improved cooker wherein there is minimal wastage of heat, wherein the alarming device (the whistle) functions efficiently and gives out a warning signal that has some correlation with the stage of cooking of the cooking medium, and which allows stirring or watching the contents without interfering with the signaling device. Accordingly this invention provides a cooker with a signaling device indicating the stage of cooking comprising a vessel (V) and a whistle (W), said whistle having a whistle body (B) housing a cavity (C) communicating with the mouth (M) of the whistle through a narrow orifice (O) and with the exterior through another opening (P) situated on the wall of the whistle body, characterized in that a small container (N) is provided in connection with the said vessel, said small container (N) extending to the bottom of the vessel, and means provided for fitting said whistle on to the said small container (N) with the mouth (M) of the whistle opening to the interior of the small container (N) and its opening (P) communicating with the exterior in the fitted position of the cooker. The small container for taking the water for energizing the whistle has a mouth capable of being fitted by the said whistle through the mouth of the latter. The mouth of the said small container is preferably disposed outside the vessel so as to enable a loud whistle to be heard. At the least the external opening of the said whistle should communicate with the exterior for an audible whistling some. The small container should be positioned near the heat source so as to reflect the temperature of the vessel when both are heated together. The small container and said vessel may preferably be in contact with each other over a part of their body walls so as to enable the heat to be exchanged between the two compartments. Alternately and preferably the wall of the vessel itself forms one of the walls of the small container i.e. they share a common body wall portion. This can be achieved by welding the outer wall of the small container on to the vessel wall. Heat from the vessel would then pass over to the water taken in the small container through their common wall enabling better reflections the temperature. Too much spaced covering of the bottom of said vessel by the small container would result in inefficient heating. Therefore said common body wall portion extends over less than half of the bottom of the vessel. The bottom of the cooker according to this embodiment is therefore single walled over a majority of its extent so as to ensure that too much heat is not wasted in heating up the double walled base. Unlike the existing double walled milk cooker, in the preferred embodiment of this cooker the small container (N) is provided on the sidewall of the vessel and its horizontal circumferential extent is less than the full circumference of the vessel. The purpose of the water in the small container (N) is only to produce the whistle in order to show that the contents of the vessel have been brought to or near its boiling point. As such the small container (N) need not hold beyond a few milliliters of water. This would also avoid wastage of heat. Therefore in deciding the dimensions of the small container one should take into consideration this point along with such other points as the fact that the whistle is better provided on the side of the cooker for easy operation. The invention is mainly intended for cooking in a non-pressurized environment or at pressures slightly above the atmospheric pressure as standard pressure cookers already have an indicator in the hissing sound produced at their safety valve. Electric kettles and sterilizers having a heating element kept attached to and insulated from the vessel may also be provided with an attached small container having a whistle. The whistling sound would indicate that cooking has progressed to a certain extent and in suitably selected models the cessation of the whistle would signify the commencement of dry heating when the electric current is to be manually switched off. The invention will now be described with reference to the accompanying drawings, wherein:- Fig.l: is the sectional elevation of a preferred embodiment of the cooler according to the invention; Fig.2: is the sectional plan view of the cooker shown m Fig.l, the section passing through the plane Y-Y shown in Fig.l; Fig.3: is the sectional elevation of the whistle fitted on the cooker; Fig.4: is the pictorial view of the whistle used in the invention; Fig.5: is the bottom view of the whistle shown in Fig.4; Fig.6: is the sectional elevation of another embodiment of the cooker according to the invention; Fig.7: is the sectional elevation of another cooker according to the invention; Fig.8: is the sectional plan view of the cooker shown in Fig.7, the section passing through Ae plane X-X shown in Fig.7. As shown in the figures the cooker according to the invention comprises a vessel (V) for holding the medium to be cooked, a whistle (W) and a small container (N) provided in connection with the said vessel (V) for holding the water to energize the whistle, said whistle having a whistle body (B) having a blind or open cavity (C) commimication with the mouth (M) of the whistle through a narrow orifice (O) and with the exterior through another opening (P) situated on the wall of the whistle close to the said narrow orifice (O), means provided for fitting said whistle on to the said small container (N) such that the mouth (M) of the whistle opens to the interior of the small container (N) in the fitted position of the whistle on the cooker. The whistle usually has a whistle tongue (S) that separates the mouth of the whistle from the cavity (C) of the whistle, for producing a loud whistling sound. The external opening (P) of the whistle is disposed outside the vessel in the embodiments illustrated. In the preferred embodiment shown in Figs.l to 2, the wall of the vessel (V) forms one of the walls of the small container, the other wall of the small container (N) being hermetically joined to the vessel (V) at their line of contact. The common body wall portion between the two containers is marked as (L). (E) and (F) are the points of contact of the external wall of the small container with the vessel wall seen in a vertical section and (G) and (H) are the points of contact seen in a horizontal section. The whistle (W) is fitted on the ferrule provided on the small container, through threaded connections. In the embodiment shown in Fig.6, the upper part of the small container is positioned outside the vessel, the lower part of said small container being positioned within the vessel in the lower half of the vessel (V) spaced fiow the bottom wall of the vessel, said small container (N) being fitted to the vessel (V) at the junction of their walls, the whistle being fitted on the threaded ferrule provided on the external part of the small container (N). This embodiment is suited for electrical heating by an immersed resistor. In the embodiment shown in Figs.7 to 8, the small container (N) kept in contact with the vessel (V) is fitted to the vessel by a strap (T) that is passed around the neck of the small container (N) and riveted to the vessel (V) by the rivets (R). The medium to be cooked is taken in the vessel (V) and some water in the small container (N), the whistle (W) is fitted and the cooker placed on the stove. As the contents of the vessel (V) are brought to boil, the water in the small container (N) also boils to energize the whistle (W). The timing of the whistle may be a little before the boiling of the cooking medium, the same time as or sometimes a little after the boiling of the medium within the vessel, depending on various factors as the conductivity of the metal of the cooker, the wall thickness, the size and extent of the small container, the position and strength of the heat source and these can be adjusted and specified to provide the desired timing. The operator can then know that the cooking has progressed to the desired extent. For using as a milk cooker the milk is taken in the vessel and a little water in the small container (N), the whistle fitted and the cooker placed on the stove. The cooker specifications are such as to provide a whistle before the boiling of the milk in the vessel and the embodiment according to Figs.l to 2 with the small container crossing the center of the bottom of the cooker is best suited for the purpose. The water boils first to energize the whistle. Unlike the existing milk cookers the operator showily immediately rush to the milk cooker when the whistle is heard. The milk would boil over in a few minutes and she can take out the cooker or turn off the flame just as the milk boils. There is minimal wastage of heat and the milk is readily brought to boil according to this milk cooker. The correlation between the temperatures of the cooking medium in the vessel (V) and of the water in the small container (N) could be improved by using a highly conducting metal such as copper for the bottom of the cooker and/or by providing a sufficiently thick wall for the cooker. By providing the small container at or near the source of heat the temperature of its contents can be adjusted to reflect the temperature of the vessel contents. In the embodiments of the type shown in Figs.l to 2 that are usually kept on open stoves, the lower end of the small container preferably reaches up to or crosses the center of the bottom of the cooker so that the contents of the small container are seldom brought to boil after the contents of the vessel. Usually in these stove-heated cookers the lower end of said small container is disposed within 10 cm from the center of the bottom of the vessel (V). The vessel of the cookers illustrated may be provided with a lid. The preferred embodiment of the cooker according to the invention is the one shown in Figs.l to 2 and is particularly suited for direct bottom wall heating. In the cooker shown in Fig.6 and that shown in Figs.7 to 8, the correlation between the boiling within the two chambers is poor. I claim: A cooker with a signaling device indicating the stage of cooking comprising a vessel (V) and a whistle (W), said whistle having a whistle body (B) housing a cavity (C) communicating with the mouth (M) of the whistle through a narrow orifice (O) and with the exterior through another opening (P) situated on the wall of the whistle body, characterized in that a small container (N) is provided in connection with the said vessel, said small container (N) extending to the bottom of the vessel, and means provided for fitting said whistle on to the said small container (N) with the mouth (M) of the whistle opening to the interior of the small container (N) and its opening (P) communicating with the exterior in the fitted position of the cooker. 2. The cooker as claimed in claim, wherein said small container (N) is provided on the sidewall of the vessel and its horizontal circumferential extent is less than the full circumference of the vessel. 3. The cooker as claimed in claims 1 to 2, vineries said vessel (V) and small container (N) share a coercion body wall portion (L). 4. The cooker as claimed in claims 1 to 3, wherein said small container (N) extends to the bottom of the vessel. 5. The cooker as claimed in claims 3 to 4, wherein said common body wall portion (L) extends over less than half of the bottom of the vessel. 6. The cooker as claimed-in claims 1 to 5, wherein the mouth of the said small container (N) for fitting the whistle is disposed outside the vessel. 7. The cooker as claimed in claims 1 to 6, wherein said small container (N) towards its lower part is positioned within the vessel in the lower half of the latter spaced fix)m the bottom wall of the vessel and towards its upper part is positioned outside the vessel, the whistle being provided on the said external part of the said small container. 8. The cooker as claimed in claims 1 to 7, wherein means for electrical resistance heating is provided attached to the cooker. 9. The cooker as claimed in claims 1 to 8, wherein said whistle has a whistle tongue (S), said narrow orifice (O) being bounded between the tongue of the whistle and the whistle body (B), for producing a loud whistling sound, 10. A cooker with a signaling device indicating the stage of cooking substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

Documents:

2257-mas-1998-abstract.pdf

2257-mas-1998-claims filed.pdf

2257-mas-1998-claims granted.pdf

2257-mas-1998-correspondnece-others.pdf

2257-mas-1998-correspondnece-po.pdf

2257-mas-1998-description(complete)filed.pdf

2257-mas-1998-description(complete)granted.pdf

2257-mas-1998-drawings.pdf

2257-mas-1998-form 1.pdf

2257-mas-1998-form 19.pdf

2257-mas-1998-form 3.pdf