Background of the Invention As experienced by those engaged in more extensive cooking, such as chefs in hotels, restaurants or other like institutions, where cooking is performed on a large scale and throughout many hours of the day, it is very tedious to frequently ignite the gas range or an array of gas ranges; thus, once a gas range is ignited in the morning, it is left on during most of the working day, even when not in use, resulting in a substantial waste of gas.

Summary of the Invention It is therefore a broad object of the present invention to provide a gas- saving arrangement for gas-fired cooking equipment, wherein gas flow to the burner is stopped whenever there is no cooking utensil placed on the grate over said burner, or, in the case of ovens, on a rack under said burner.

It is a further object of the present invention to provide a gas-saving arrangement for gas-fired cooking equipment, in which the gas burner will ignite whenever a cooking utensil is placed on the grate over said burner or, in the case of ovens, on a rack under said burner.

Thus, the invention provides a gas-saving arrangement for gas-fired cooking equipment, including a gas burner connectable to a gas source via a gas tap, a support for supporting a cooking utensil in a cooking position, and means for igniting the gas, said arrangement comprising sensor means operating to detect the presence or absence of a cooking utensil upon said support in said said sensor means, connected to a gas line between said gas tap and said burner; whereby, when said sensor means detects the absence of a cooking utensil upon said support in the cooking position, the valve is closed and the flame is extinguished.

The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood.

With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

Brief Description of the Drawings Fig. 1 is an isometric view of a gas-saving arrangement for gas-fired cooking equipment according to the present invention; Figs. 2 and 3 are detailed illustrations of a first embodiment of the arrangement of Fig. 1, showing two operational states; Fig. 4 is an illustration of a further embodiment of a gas-saving arrangement according to the present invention; Fig. 5 illustrates, on an enlarged scale, the structure of the sensor shown in Fig. 4; Fig. 6 shows a further embodiment of the gas-saving arrangement of the present invention; Fig. 7 depicts a modification of a sensor structure for the gas-saving arrangement according to the present invention; Fig. 8 is an isometric view of an embodiment of the present invention to be used in a gas oven, and Fig. 9 is an isometric view of an electric embodiment of the invention to be used in a gas oven.

Detailed Description of Preferred Embodiments There is seen in Fig. 1 a gas-saving arrangement for gas-fired cooking equipment according to the present invention. For purposes of simplicity, there is illustrated a gas range 2 having only a single gas burner 4 disposed in a housing 6; however, it should be understood that the invention is utilizable just as well with gas ranges including more than a single burner, such as, for example, an array of two or more gas burners mounted in a single housing, or an array of longitudinally arranged, juxtaposed gas burners. The gas range 2 further includes a gas conduit 8, leading from a gas source to burner 4 via a standard gas tap 10.

A grate 12, upon which a cooking utensil is to be placed and which may have any desired configuration, is positioned over burner 4. An electronic ignitor or a gas pilot ignitor 14 is located adjacent to burner 4. The arrangement according to the present invention further consists of one or more sensors 16, which may be constituted by sensors of various types, as will be described further below. As is seen in Fig. 1, the free edge of sensor 16 protrudes from the upper surface of grate 12, in spaced-apart relationship to burner 4.

Referring now to Figs. 2 and 3, leading from gas tap 10 to burner 4 is conduit 20, to which is affixed a mechanically actuatable valve 22. Valve 22 is operationally connected to sensor 16 by means of link 24. In this embodiment, sensor 16 is a mechanical sensor, such as a spring-biased, peg-shaped member which mechanically activates and deactivates valve 22. A flame detector 28, such as a thermocouple, an ion sensor, a thermistor or the like, electrically connected to an actuatable gas valve 30, may also be advantageously provided to ensure that gas flows only when the burner is in standby to be activated by the sensors. It is normal practice to include this safety feature within main tap 10, instead of providing a separate unit.

The gas-saving arrangement 2 operates as follows: when the gas tap 10 is turned on, the pilot flame is lit by conventional means, and thermocouple 28 keeps the main gas tap 10 open. When a cooking utensil 32 is placed upon grate 12, the sensor 16 is pressed down and activates valve 22 by means of link 24. The gas that flows through conduit 20 to burner 4 is then ignited by conventional means. When cooking utensil 32 is removed from the grate, the sensor 16, being spring-biased, returns to its original state and deactivates valve 22, thus stopping the flow of gas within conduit 20 and extinguishing the flame. If the burner is extinguished for some reason while utensil 32 is located upon grate 12 and the sensor 16 is pressed down, the detector 28 will sense same and will cause valve 30 to close, thus stopping the flow of gas within conduit 20 towards burner 4.

An electronic embodiment of the present invention is shown in Figs. 4 and 5. In this embodiment, sensor 16 is adapted to activate a microswitch 34 when it is pressed down by utensil 32. Microswitch 34 is electrically connected, via leads 36, to a control circuit 38. Control circuit 38 is electrically wired to gas valve 30 via leads 40, and detector 28 is wired to the control circuit via leads 42.

In addition, control circuit 38 is also connected to the electronic ignitor 14 via leads 44. An ON-OFF switch 46 is optionally provided, electrically connected via leads 49 to control circuit 38, for connecting control circuit 38 to, or disconnecting it from, any suitable power source (not shown).

The operation of the gas-saving arrangement according to the embodiment of Figs. 4 and 5 is as follows: when a cooking utensil is placed upon grate 12, sensor 16 is pressed down, activating microswitch 34, which in turn activates control circuit 38, causing the opening of valve 30. Electronic ignitor 14 is then sparked to ignite the gas flowing out of burner 4. Upon the removal of the cooking utensil from grate 12, microswitch 34 opens, effecting the closing by control circuit 38 of the gas valve 30. If the flame is accidentally extinguished, the thermocouple 28 (or any other suitable flame presence detector) will detect the absence of the flame and signal the control circuit, which will then close valve 30.

If desired, control circuit 38 may be furnished with a time delay selector 48 for adjusting the length of delay between the removal of the utensil from grate 12 and the detection thereof by the sensor, and extinguishing of the flame, so as to allow the removal of the utensil from the grate for stirring or other brief cooking procedures, while keeping the flame burning for continuation of the cooking process.

The embodiment of Fig. 6 is a modification of that shown in Figs. 4 and 5, wherein, instead of electronic ignitor 14, there is provided a gas pilot ignitor 50 connected via conduit 52 to conduit 20. Such an arrangement may prove to be more effective for frequent ignitions of the flame.

A further modification is shown in Fig. 7. In this embodiment, the grate 12 is itself movably mounted, so that when a cooking vessel is placed thereon, the entire grate is pressed downwardly against the force of springs 54, thus actuating a microswitch or plunger 56 which opens valve 22. Otherwise, this embodiment operates in the same manner as described above with regard to Figs. 4 and 5.

Fig. 8 illustrates an embodiment of the invention to be used in an oven 60 having an overhead burner 62. For the sake of simplicity, only one burner is shown; however, several overhead or bottom burners can be used. A main gas inlet conduit 64 feeds gas to main switch 66, from whence it passes to main gas tap 68. Main gas tap 68 contains all of the thermostat and timer features usually provided with this type of oven. The gas flows from main gas tap 68 through conduit 70 to control valve 72, and then to mechanically operated, plunger-type valve 74 and finally, via conduit 76, to burner 62.

The embodiment of Fig. 8 operates as follows: the main gas tap 68 is opened and pilot ignitor 78 is lit by conventional means. Thermocouple 80, which is conveniently placed near the ignitor, holds control valve 72 open. A food tray 82 is inserted into oven 60, and it presses on the sensor 84 (embodied by the plunger-operated valve 74), which is activated when the tray is fully inserted into the oven. Sensor 84 then mechanically opens valve 74, thus allowing gas to reach burner 62 via conduit 76. When the food tray 82 is removed from the oven, the spring-loaded plunger is released, deactivating valve 74 and stopping the flow of gas to burner 62.

Fig. 9 illustrates an electric embodiment of the oven arrangement shown in Fig. 8. An electric control 86 is added, connected via leads 88 to control valve 68. The thermocouple or flame sensor 80 is connected to the control 86 via leads 90, and ignitor 78 is connected thereto via leads 92. A microswitch 94 is placed near sensor 80 and is connected to control 86 via leads 96.

When the food tray 82 presses on sensor 84, it activates microswitch 94.

Control unit 86 then activates ignitor 78 and opens control valve 68 to allow the ignition of burner 62. The thermocouple or flame sensor 80 will ensure that no gas will flow to the burner in the event that the flame is accidentally extinguished. When sensor 84 is deactivated, the gas will then stop flowing to burner 82, either immediately or after a predetermined delay.

It should be understood that further modifications of the invention are also envisioned, in which proximity sensors of any kind can be utilized to detect the placement of a cooking utensil upon the grate or within the oven.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.