Abstract: Before a transaction takes place between a plurality of agent-based devices (21-29), not all of which have previous experience of each other, a data file is created which identifies all the agents which are to take part in the transaction. The data file is circulated to all the agents, and each agent endorses the data file in respect of each other agent with a positive, negative, or conditional endorsement, based on stored data indicating whether that agent is capable of co-operation with the other agent. A negative endorsement is applied by an agent in respect of any agent with which it is not prepared to co-operate. Such a negative endorsement is fatal to the transaction. A positive endorsement is applied by an agent (21) in respect of any other agent (27) with which it is unconditionally prepared to co-operate.

Abstract: A vacuum system has a cabinet that can be mounted to a wall. The cabinet includes a hose connectable to a vacuum source. The hose is extendible from the cabinet between extended and retracted positions. A rotatable shaft drives the hose and a power source causes the rotatable shaft to rotate. A sensor measures the speed of rotation of the shaft and signals a controller to stop the power source when the speed falls below a predetermined threshold.

Abstract: A vacuum cleaner has a housing that includes a separation chamber and collection chamber, a floor unit with a suction opening, and a passage between the suction opening and separation chamber. A suction source establishes a stream of air from the suction opening to the separation chamber for separation of liquids and contaminants. A controller stops the suction source when a level of liquid in the collection chamber rises to a predetermined level. There is a protective structure to shield at least a portion of the controller from circular movement of the liquid in the collection chamber. A structure in the separation chamber defines a path for the stream of air along an internal perimeter of the separation chamber.

Abstract: An improved heating unit (10) used in a cooktop (12). Operation of the heating unit is by a controller (16). An electric current is applied to a composition heating element (20). The heating element is supported on a cake (24) of insulation material installed in a pan (22) located beneath a glasstop (14) of the cooktop. A thermal sensor (28) senses the temperature of the heating element and supplies an indication of the heating element temperature to the controller which changes the amount of current supplied to the heating element as a function of the sensed temperature.

Abstract: The present invention provides a modular heating unit for a grill. The grill has a grill plate supported on a support base. The grill plate has a bottom surface and a top surface. The modular heating unit is mounted to the bottom surface of the grill plate and has at least four side edges. The modular heating unit has a pan, an insulation layer and a heating element. The pan has a generally flat base and a circumferential sidewall. The insulation layer has an insulation base and a circumferential sidewall. The heating element is supported on the insulation base to heat the grill plate and is positioned in a spaced apart relationship to the bottom surface of the grill plate. The modular heating unit is divided into a center section and two side sections. The side sections are adjacent to two side edges of the modular heating unit. The heating element is contoured to provide more heat to at least one of the side sections than the center section of the heating unit.

Abstract: An improved heating unit (10) used in a cooktop (12). Operation of the heating unit is by a controller (16). An electric current is applied to a composition heating element (20). The heating element is supported on a cake (24) of insulation material installed in a pan (22) located beneath a glasstop (14) of the cooktop. A thermal sensor (28) senses the temperature of the heating element and supplies an indication of the heating element temperature to the controller which changes the amount of current supplied to the heating element as a function of the sensed temperature.

Abstract: A grill (100) includes a hot plate (102) on one side of which is a cooking surface (104) upon which food to be cooked is set. A heating unit (106) installed on the underside (108) of the hot plate is used to heat the grill so the cooking surface temperature is a desired temperature. The unit includes a radiant heating element (110) and a pan (114) in which the heating element is installed. A cavity (C) defined by the underside of the grill, a sidewall (118) of the pan, and a top surface (122) of an insulation material (120) in which the heating element is supported, is heated to a uniform temperature across the cavity, and the grill is heated to this temperature. This uniformity of temperature results in food placed anywhere on the grill rapidly heating to a desired temperature and the food being cooked uniformly throughout.

Abstract: A cooking appliance includes a heating unit (10) for cooking food. The unit has a heating element (34) to which electrical current is supplied for generating heat used to cook food such as chocolate and sauces set upon the heating unit. A programmable controller (16) controls the application of current to the heating element to control the heating element temperature as a function of a time and temperature profile established for cooking the food in a particular manner. A temperature sensor (38) senses the heating element temperature and supplies a signal (St) to the controller. The characteristics of this signal are a function of the sensed cooking temperature. The controller is responsive to this signal, and other inputs (24,26) such as desired cooking time, and the amount and quantity of food, to vary the amount of current supplied to the heating element. The appliance is particularly useful in being able to heat chocolate, sauces, and the like without scorching them.

Abstract: A heating unit (H) for a cook top includes a ribbon-type heating element (E). The heating element is mounted on the upper surface of a cake (I) of microporous insulation material. The heating element is arranged in a predetermined pattern on the material and a plurality of staples (10) are used to attach and hold the heating element on the material surface. Each staple is a microwire staple and the staples are spaced along the length of the heating element to mount the heating element to the insulation. The microwire staples have a small thermal mass and so do not create heat sinks at their locations of use. Thus, they do not affect the efficiency of heat transfer between the heating element and that which is being heated. The staples are also preferably of the same metal alloy as that from which the heating element is formed so the staples can withstand high temperatures and numerous temperature cycles to provide a long service life.

Abstract: A modular radiant heater unit (10) is for use in a stove top (RT) designed for installation of a tubular coil type heating unit (C). The heater can either use a coil (12), or a ribbon heating element (14). The element rests upon a cake (20) of an insulation material fitted within a pan (16) sized to be installed in an opening (6) in the stove type in which a coil type heating unit is normally installed. The heating unit has an electrical connector (24) adapted to readily connect with the electrical connector installed in the stove top. A radiant glass cover (30), sized to fit over the heater unit, is fitted over the pan and held in place by an annular ring (34) which fits about the circumference of the pan and a shield (38) which covers a gap (6) between the heater unit and stove top. Utensils for cooking food are placed upon the glass top. The heater control (K) normally used to control the temperature of a tubular, coil heater, is now used to control the temperature of the radiant heater unit.

Abstract: A heating unit (H) for a cook top includes a thin and relatively fragile resistive heating element like, but not necessarily limited to, a ribbon (E). The heating element is mounted on the upper surface of a cake (I) of microporous insulation material. The heating element is arranged in a predetermined pattern on the material and a plurality of staples (10) are used to attach and hold the heating element on the material surface. Each staple is a glass staple and the staples are spaced along the length of the heating element to mount the heating element to the insulation. The staples are electrically non-conductive and do not create heat sinks at their locations of use. Thus, they do not affect the efficiency of heat transfer between the heating element and that which is being heated. The staples are also of a glass material which can withstand high temperatures and numerous temperature cycles to provide a long service life.