DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] In FIGS. 1 and 2 of the accompanying drawings there is schematically depicted a cooking/stirring appliance 10. The appliance 10 includes a base 3 supporting a vessel 2. The base 3 might be formed of plastics, ceramic or metallic material for example, whereas the vessel 2 might be formed of aluminium, stainless steel or other heat-conducting waterproof material. Covering the vessel 2 is a lid 1 that would typically be formed of glass, polycarbonate or other heat resistant material that is preferably light-transmissive or transparent.

[0037] A heater 6 fixed to the reservoir 17 heats water 15 within the reservoir 17 to create steam 16.

[0038] A space alongside or under the reservoir 17 houses an electric motor 19 having an output shaft 18 that engages with a vertical drive shaft 11 and coupling arrangement which passes through the center post 23 of the reservoir 17.

[0039] The vessel 2 includes a centrally located tube 20 through which a vertical shaft 21 of a stirring blade 5 extends to engage and couple with the vertical drive shaft 11. The stirring blade 5 is typically fabricated from moulded plastic material and is sized and shaped to just clear the floor of the vessel and a short, lower portion of the vessel side wall.

[0040] A steam switch 9 is positioned beneath the reservoir 17 which includes a longitudinal steam tube 12 extending from a position above the liquid 15 in the base reservoir 17 to a position adjacent to the steam switch 9.

[0041] The steam switch 9 is associated with a control circuit positioned at 8 for example. A thermister or a thermostat might alternatively be substituted for the steam switch.

[0042] The blade 5 can have mounted above it and on the same axis, a free-rotating blade 4 that is free to rotate in either direction but would typically be provided as a unit with blade 5. That is, one blade would typically not be removable from the other. The blade 4 is sized and shaped to just clear the wall of the vessel 2. The free-rotating blade 4 is intended to flip the food over the stirring blade all five to encourage proper stirring and mixing.

[0043] Situated within the vessel 2 is a short abutment wall or stop 13 with which the free-rotating blade 4 can engage. As a result of this engagement, rotation of the free-rotating blade 4 is inhibited. If the stirring blade 5 reverses direction as a result of an overload condition, the free-rotating blade or for will reverse through one revolution and till it engages the stop 13 again. At this point, the free-rotating blade acts again as a flipper. The reason for this “dead movement” is to allow for the necessity of just a single stop 13 so that the user can position the free-rotating blade at almost any orientation, rather than having to fit the distal end of the free-rotating paddle into a slot formed on the inner surface of the receptacle for example.

[0044] A lid 1 is supplied to fit the vessel 2 to reduce heat loss, evaporation and consequent drying of the mixture 14 when the sauce making has been completed.

[0045] In use water 15 is added to the reservoir 17 by measure or to a mark shown in the reservoir. The vessel 2 is then fitted to anti-rotation locations (not shown) at the top of the reservoir 17 causing a snug fit between the two components. Water and steam in the reservoir will be recycled and therefore heating/re-heating can continue for a long period, due to the snug fit between the base 3 and the vessel 2 and the action of the steam switch 9.

[0046] The blade assembly 4 & 5 is then fitted into the vessel, whereupon the shaft 21 couples with the motor output shaft 11. Liquid and solid components (the mixture 14) are then added to the vessel 2 in accordance with a user-selected recipe. The motor 19 and heater 6 are then energised. The blade assembly 4 & 5 then rotates in the mixture 14 combining the ingredients and other ingredients as might be added to the mixture from time to time. After a period, some of the water 16 in the reservoir 17 will be turned to steam 16 condensing on the base of the vessel 2 and giving up its latent heat to heat the ingredients 14 being mixed in the vessel 2. Due to the nature of steam 16 it does not get hotter than the temperature of boiling water 15 and therefore the ingredients 14 do not burn. After condensing on the base of the vessel 2 the condensate returns to the reservoir 17 for re-heating and the cycle continues. If excess boiling occurs in the reservoir 17, there will be an excess of steam 16 that will be forced by pressure to move downward through the steam tube 12 and exit to condense on and activate the steam switch 9.

[0047] To ensure that the ingredients 14 are mixed well, the stirring blade 5 is shaped such that it has a substantially triangular cross section 22 as shown in FIG. 3 to allow the ingredients 14 to be forced upward as the blade 5 rotates and moves through the mixture 14. If the load on the blade 5 is excessive the motor 19 will automatically reverse as a result of a sensing device, or from the provision of a synchronous motor that reverses upon sensing overload. The blade 5 will also reverse direction when chunky food 14 becomes lodged on top of the blade 5 jamming against the blade 4, causing the blades 4 and 5 to move as one. Within one revolution, the blade 4 engages the short abutment wall or stop 13 on the vessel 2, causing resistance, which the motor 19 can sense to reverse the stirring action and release the jam. That is, food caught between the free-rotating blade and the stirring blade will result in the two blades being effectively fixed to one another. Abutment of the free-rotating blade with the stop 13 will therefore also stop rotation of the stirring blade to thereby overload the motor.

[0048] Possible uses of the appliance are to make sauce, soup, stews, beans, spaghetti, jams, scrambled eggs and many other dishes.

[0049] An embodiment comprising a different stirring blade arrangement is depicted in FIGS. 4 and 5. In this embodiment, there is a star-shaped mixer 21 including three radially extending stirring blades. The mixer 21 coupled at a drive coupling 25 to an outer gear within the gear casing 23 and depends from the gear casing within which a gear system 24 is located. The gear system 24 includes a mounting arrangement 26 including a bearing surface 27 by which the gear casing is rotatably mounted to the hollow cylinder 20. The gear casing 23 rotates about the hollow cylinder 20 by action of the motor output shaft 18. There is a fixed gear that engages with the shaft 21 such that rotation of the casing 23 caused by rotation of shaft 21 causes the casing to rotate about the centre axis of the cooking vessel. As other outer gear is in mesh with the inner gear, the outer gear rotates to thereby effect orbital movement of the star-shaped mixer 21 about the centre axis of the vessel 2 and rotation of the mixer 22 about its own vertical axis. Each blade of the mixer 21 includes distal edges that extend substantially to the wall of the vessel 2 and its floor. Operation of this embodiment is otherwise much the same as that of the embodiment depicted in FIGS. 1 to 3.

[0050] It should be appreciated that modifications and alternations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention.