Abstract:
A device for collecting data relating to a cooking and/or heating process performed on a hob comprising at least one sensor associated with wireless data transmission means and means for receiving the signals transmitted from the data transmission means and connected to a hob management system for the purpose of permitting automatic control of the process. The sensor is fitted substantially at one end of a kitchen utensil suitable for coming into contact with the food to be cooked and/or heated, while the data transmission means are arranged in the handle of the kitchen utensil.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a device for collecting data relating to a cooking and/or heating process performed on a household kitchen appliance, in particular on a hob, of the type comprising a sensor associated with wireless data transmission means and means for receiving the signals transmitted by the data transmission means and connected to a management system for the household appliance for the purpose of permitting automatic control of the process. 
     2. Description of the Related Art 
     A device of this type is illustrated, for example, in application DE 44 39 777, in which the temperature sensor and the radio-frequency transmission means are arranged in the handle of an item of cookware (pan, skillet or the like). This has the disadvantage both of a certain disparity between the temperature detected by the sensor and the temperature of the food contained within the item of cookware and of the necessity of providing a plurality of items of cookware each having a handle fitted with a sensor and transmitter. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a device of the type stated at the beginning of the description, which allows the above-stated disadvantages to be overcome in a simple and economic manner. 
     According to the invention, said object is achieved in that the sensor is fitted substantially at one end of a kitchen utensil suitable for coming into contact with the food to be cooked and/or heated, and in that the data transmission means are arranged substantially in a handle of the kitchen utensil. 
     The definition of kitchen utensil includes all types of ladles, slotted spatulas, spoons, forks and the like used for stirring and/or removing the food during cooking or heating. The definition of sensor includes any type of sensor, for example temperature, conductivity, level, color, density, acceleration or vibration sensors. In the event that the sensor is a conductivity sensor, it can be used to check whether the end of the kitchen utensil is actually in contact with the liquid in the item of cookware and simultaneously to monitor changes in conductivity due to the addition of salt or starchy foods (pasta, potatoes etc.). According to a preferred embodiment of the invention, the kitchen utensil has a removable portion at the first end, such that the user can easily change one type of kitchen utensil into another without losing the technical features associated with the presence of the sensor and the associated signal transmission means. In some cases, when the user does not consider it necessary to stir the food contained, for example, in an item of cookware, the utensil can be used without the removable portion, i.e. purely to collect and transmit the temperature of the food to the domestic appliance control unit. 
     According to another preferred embodiment of the invention, the sensor and associated transmitter can easily be fitted to a conventional kitchen utensil. 
     According to another variant of the invention, the kitchen utensil (once the portion suitable for mixing the food has been removed) is fitted in a hole in a suitable lid of an item of cookware, said lid advantageously being of the type adaptable to different types of cookware. To this end, said lid has a substantially conical shape capable of fitting into different diameters of pans or the like. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages and features of the control device according to the invention will emerge from the following detailed description, which is provided purely by way of non-limiting example, with reference to the attached drawings in which: 
     FIG. 1 is a diagrammatic view of a kitchen utensil according to the invention in its first configuration; 
     FIG. 2 is a diagrammatic view of the kitchen utensil in FIG. 1 fitted with an accessory in a configuration for use as a ladle; 
     FIG. 3 is a view of the utensil in FIG. 1 fitted with an accessory suitable for imparting the function of a slotted spatula to the utensil; 
     FIG. 4 is a view of the utensil in FIG. 1 used in combination with a suitable lid according to the invention; 
     FIG. 5 is a similar view to FIG.  4  and illustrates the use of the utensil in FIG. 1 in association with the lid of a pan for steam cooking; 
     FIG. 6 is a diagrammatic view of a kitchen utensil according to another variant; 
     FIG. 7 is a diagrammatic view of an accessory to be used with the utensil in FIG. 6; 
     FIG. 8 is a diagrammatic view of the appearance of the kitchen utensil in FIG. 6 fitted to the accessory in FIG. 7; 
     FIG. 9 is a diagrammatic view of a variant of the utensil of FIG. 6 configured for use as a sensor; 
     FIG. 10 is a block diagram of a transceiver associated with the kitchen utensil according to the invention; and 
     FIG. 11 is a block diagram similar to the diagram in FIG.  10  and illustrates a “transponder”-type signalling device associated with the kitchen utensil according to the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the drawings,  10  denotes the overall kitchen utensil comprising a hollow handle  10   a  connected to a tubular shaft  10   b , the free end  12  of which is associated with a first temperature sensor  14 . The sensor  14  is electrically connected to a transmitter  16  contained in the handle  10   a  which, as will be clear from the description below, co-operates with a receiver with which the hob is equipped, said receiver being connected to the hob&#39;s central control unit (not shown). The handle  10   a  of the utensil  10  is moreover equipped with a second temperature sensor  18  suitable for measuring the temperature of the handle itself. The temperature sensors  14  and  18  have low thermal inertia and can, for example, be NTC, KTY, RDT sensors or thermocouples. 
     In a first variant of the invention, the sensors and the transmitter are provided with electrical power by batteries (not shown) accommodated in the handle  10   a  and the batteries are advantageously rechargeable. In this case, the handle  10   a  can be equipped with a photovoltaic cell, which ensures that the batteries remain charged. 
     An accessory can readily be fitted in a manner known per se to the end  12  of the kitchen utensil  10 , which accessory is capable of allowing the kitchen utensil  10  to be usable for all purposes such as a ladle, slotted spatula, serving spoon, potato masher or the like, without losing its function as a temperature sensor suitable for automatically managing the cooking and/or heating process. For example, FIG. 2 illustrates the use of an accessory M that converts the utensil  10  into a ladle, while FIG. 3 illustrates the use of an accessory S that converts the kitchen utensil  10  into a slotted spatula. 
     FIGS. 4 and 5 illustrate the use of the kitchen utensil  10  with two different types of lids. FIG. 4 shows a special lid  20 , which is shaped such that its lower face  20   a  is substantially conical in shape so that it is readily able to fit into pans P of differing diameters. A hole  24  is provided centrally in the lid  20 , corresponding to the lid handle  22 , through which hole is passed the shaft  10   b  of the kitchen utensil  10 , in this case without mixing or removing accessories, acting solely as a temperature sensor. The hole  24  can also be made non-centrally in the lid  20 . FIG. 5 shows the use of the utensil  10  in association with the glass lid of a steam cooking pan W, the shaft  10   b  of the utensil  10  being inserted into a suitable steam vent hole  26  equipped with a rubber seal  26   a . The kitchen utensil according to the invention can advantageously be used with pressure cookers. In this case, a temperature and pressure sensor is fitted to the end  12  of the kitchen utensil  10 . 
     FIG. 6 illustrates a variant of the kitchen utensil according to the invention, in which the handle  100   a  is integral with a spiral-shaped shaft  110   b  also equipped at its free end with a temperature sensor  114 . The particular shape of the shaft  110   b  makes it easy to fit accessories (such as that denoted M′ in FIG. 7) in a similar manner to that already described for the arrangements of FIGS. 2 and 3. 
     FIG. 9 illustrates a variant of the kitchen utensil  100  shown in FIG. 6 in which the handle  110   a  is equipped with a lateral support  130  suitable for co-operating with the side wall of a pan for the purpose of maintaining the temperature sensor  114  in a stable position at a predetermined distance from the bottom of the pan. 
     FIG. 10 provides a diagrammatic description of the circuit diagram of the receiver/transmitter  16  associated with the handle  10   a  of the kitchen utensil  10  and powered, for example, by batteries, together with the diagram of the transmitter/receiver A associated with the hob (not shown). The receiver/transmitter  16  has one or more sensors T 1 , T 2  (for temperature, pressure etc.) connected to an a/d converter  40 , which is in turn connected to a central processing unit  41  equipped with memory. The central unit  41  processes the signal received from the sensors and, by means of an encoder  42  and a modulator  43 , supplies the driver module  44  of an antenna  45 , to which an oscillator  44 ′ is connected. The part for processing the signal received branches off the control module  44  of the antenna  45 , said processing part comprising a demodulator  46 , a filter  47  and a decoder  48 , culminating at the central processing unit of the transmitter/receiver  16 . 
     The part of the transmitting/receiving circuit A associated with the hob comprises substantially the same components as the part associated with the handle  10   a  of the kitchen utensil  10  and identical components are denoted by identical reference numerals multiplied by 100 [sic]. Obviously, the central processing unit  410  of the part of the circuit associated with the hob is connected to or is integral with the hob control unit, so as to permit automatic power control of the heating components, whether of electrical or gas type. 
     FIG. 11 shows a block diagram of the variant in which the transmitter  16  of the kitchen utensil  10  is a signaling device or “transponder” in which the sensor and electronic circuit associated therewith do not require an electrical power supply, since said circuit uses the energy captured from the electromagnetic field by the associated antenna. In FIG. 11, the reference number  50  denotes the processing unit associated with the transmitter  16 , to which are in turn connected an RF interface  51  and a memory  52 . A “TAG”-type antenna  53  is connected to this part of the circuit. The circuit A associated with the hob is substantially identical, except for the different type of antenna (denoted by the reference number  530 ) relative to the circuit described with reference to FIG.  10 . 
     SAW (surface acoustic wave) technology with a piezoelectric substrate acting as sensor can be used in the handle  10   a  of the kitchen utensil  10 . 
     The kitchen utensil according to the invention can advantageously be used for detecting the onset of boiling in a pan and for keeping the water boiling without wasting energy. The kitchen utensil according to the invention can moreover be used as an alarm, e.g. an audible alarm, to indicate when the liquid level falls below a predetermined level in the pan.