Security power interrupt - Patent Review 5734206

We claim:

1. An apparatus that interrupts delivery of electrical power from a power supply to an electrically operated device, comprising:

an electrical switching component, wherein said switching component is selectively changeable between a first condition wherein said switching component transmits power from said supply to said device, and a second condition wherein transmission of power from said supply to said device is interrupted;

a detachable component, wherein said detachable component is operative to accept input data, wherein said input data includes at least one authorization code;

a coupler, wherein said coupler detachably operatively connects said detachable component and said switching component, and wherein said switching component is in said first condition responsive to said detachable component being coupled to said coupler and said data including said authorization code, and wherein said switching component is in the second condition responsive to either said detachable component being disconnected from said coupler or said data not including said authorization code.

2. The apparatus according to claim 1 wherein said electrical switching component comprises a controller, and wherein said controller is programmable.

3. The apparatus according to claim 1 wherein said coupler comprises a detachable electrical connector, whereby said electrical connector detachably connects the detachable component and said switching component.

4. The apparatus according to claim 1 wherein said electrical switching component includes a pair of relatively movable electrical contacts, wherein in said first condition said contacts are engaged and in said second condition said contacts are separated.

5. The apparatus according to claim 1 wherein said electrical switching component includes a relay.

6. The apparatus according to claim 1 wherein said detachable component is operatively connectable with a key pad and wherein said authorization code is input through said key pad.

7. An interrupt system which is operative to interrupt the transmission of power from a power supply to an electrical load, comprising:

a controller, wherein said controller is operative to selectively supply or interrupt power to the load,

a code-providing device detachably operatively connected with the controller, wherein said code-providing device is operable to provide an authorization code to said controller when operatively connected thereto, and wherein said controller is operative to supply power to the load responsive to the code-providing device providing said authorization code to the controller, and

wherein the controller is operative to monitor the operative connection with said code-providing device, and wherein said controller is operative to interrupt power to the load responsive to said code-providing device being operatively disconnected from said controller.

8. The system according to claim 7 and further comprising a coupler, wherein said coupler is operative to releasably electrically connect said controller and said code-providing device.

9. The system according to claim 7 wherein said code-providing device is operatively connectable with a key pad, and wherein said authorization code is input through said key pad.

10. The system according to claim 7 and further comprising a pair of relatively movable electrical contacts, wherein one of said contacts is operatively connected to said supply and the other of said contacts is connected to the load, and wherein said controller is operative to supply or interrupt power by selectively causing said contacts to engage and disengage, respectively.

11. The system according to claim 7 wherein said code-providing device includes a remote control device and wherein said controller is in operative connection with a receiver, wherein said receiver receives signals from said remote control device.

12. A device for interrupting power to an electrical load comprising

means for connecting the device to an electrical power supply,

means for supplying electrical power to the load,

means for switching the device from a mode in which power to the load is interrupted to a mode in which power is supplied to the load responsive to an authorization code,

detachable enabling means coupled to the device for providing the authorization code,

means for monitoring the enabling means to determine when the enabling means has been detached from the device, and

means for interrupting power to the load responsive to detachment of the enabling means.

13. The device of claim 12 in which the means for monitoring the enabling means comprises a controller.

14. The device of claim 12 in which the means for switching the device comprises a controller.

15. The device of claim 12 in which the means for interrupting power to the load comprises a controller.

16. The device of claim 15 in which the means for interrupting power to the load comprises a relay.

17. The device of claim 14 wherein the controller is programmable.

18. The device of claim 12 in which the enabling means comprises an electronic key pad.

19. The device of claim 12 wherein the enabling means comprises a remote control receiver.

20. An interrupt device for interrupting power to an electrical load connected to an electrical power supply, comprising

a controller for switching the interrupt device between a mode in which power is supplied to the load, and a mode in which power to the load is interrupted, and

an enabling device detachably coupled to the controller for providing an authorization code to the controller,

wherein the controller monitors the enabling device and switches the interrupt device to the mode in which power to the load is interrupted in response to detachment of the enabling device.

21. The interrupt device of claim 20 in which the enabling device comprises an electronic key pad.

22. The interrupt device of claim 20 in which the enabling device comprises a remote control receiver.

23. The device of claim 20 in which power to the load is interrupted through a relay.

24. An interrupt device for interrupting power to an electrical load connected to an electrical power supply, comprising

a controller for selectively supplying or interrupting power to the load, and

a code providing device wherein said code providing device provides an authorization code to the controller, for switching the interrupt device to a first mode in which power is supplied to the load responsive to an authorization code, wherein the code providing device is detachably coupled to the interrupt device,

wherein the controller monitors the code providing device to determine when the code providing device has been detached from the interrupt device and switches the interrupt device to a second mode in which power to the load is interrupted responsive to detachment of the code providing device.

25. The interrupt device of claim 24 wherein the code providing device is operatively connectable to an electronic key pad.

26. The interrupt device of claim 24 wherein the code providing device is operatively connectable with a remote control receiver.

27. The interrupt device of claim 24 wherein power to the load is interrupted through a relay.

Description Submit all comments and votes

FIELD OF INVENTION

The present invention relates to an electrical security power interrupt apparatus, and more particularly to a device that prevents and/or controls the unauthorized use of an electrical appliance or similar electrically operated device by enabling an authorized user to select a mode which will interrupt the supply power if a high current-drawing component is activated, or upon the occurrence of other conditions.

BACKGROUND OF THE INVENTION

Many household electrical appliances and other similar electrically operated devices can be hazardous if not properly used and monitored. There are many recorded instances of disastrous home fires caused by unauthorized operation of a household appliance such as a stove by children, burglars or vandals, or persons of reduced capacity or faculties such as the elderly. It is thus advantageous to be able to selectively control the use of such appliances and similar electrically operated devices. In the prior art, means have been provided to prevent unauthorized usage of electrical appliances and similar electrically operated devices, primarily through key operated electro-mechanical circuit interrupt devices. However, such devices conventionally provide for on-off control only, meaning that the device completely interrupts the flow of electrical power to the appliance while in the interrupt or "locked" state, and it connects the appliance to the electrical supply in the operative or "unlocked" state. In the case of, for example, a stove, once the supply power has been cut off auxiliary electrical equipment such as lighting and an electrical clock also ceases to function.

SUMMARY OF THE INVENTION

The present invention provides a security power interrupt apparatus for use in connection with an electrical appliance or similar electrically operated device.

In accordance with one aspect of the invention the appliance or device retains a connection to the power supply while in interrupt or "locked" mode; complete power shutoff only occurs when a preset electrical current is exceeded, thus allowing operation of the appliance's auxiliary electrical equipment while the interrupt device is in the interrupt mode.

In a preferred embodiment, the security power interrupt device of the present invention is controlled by a detachable electronic key pad or similar detachable component capable of receiving input data, whereby predetermined input data preferably input through a sequence of key strokes interrupts or restores power to the appliance or similar device. Power is preferably supplied to the key pad by a DC current transformer from a wall outlet to which the interrupt device is operatively connected, and the appliance or other device is in turn plugged into or otherwise operatively connected to the interrupt device. Also in the preferred embodiment, the key pad is connected by a wire remotely from the main body of the interrupt device, allowing flexibility in the placement of the key pad. For this purpose the key pad may be provided with a magnet, for detachably affixing the key pad to the metallic housing of the appliance, or other affixing means.

Further, the key pad is detachable from the interrupt device, and when detached prevents the interrupt device from being switched out of the interrupt mode, thereby preventing attempts to break the coded key sequence and restore normal supply power to the appliance. The interrupt device automatically switches to the interrupt mode when the correct numerical sequence is entered on the key pad, after a preset time interval has passed since the last authorized use of the appliance or when the key pad is disconnected from the interrupt device. The feature whereby the interrupt automatically switches to the interrupt mode when the key pad is detached can also be applied to any other type of power interrupt device or similar apparatus.

The present invention thus provides a device for interrupting power to an electrical appliance or similar electrically operated device, comprising means for connecting the interrupt device to an electrical power supply, means for supplying electrical power to the appliance, means for switching the interrupt device between a mode in which power is supplied to the appliance and a mode in which power to the appliance is substantially interrupted, enabling means detachably coupled to the device for activating the means for switching the device, means for monitoring the enabling means to determine when the enabling means has been detached from the device, and means for interrupting power to the appliance responsive to detachment of the enabling means.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings that illustrate by way of example only a preferred embodiment of the invention,

FIG. 1 is a schematic perspective view illustrating the invention connected to a 220 V electric stove, with the detachable key pad mounted on a wall;

FIG. 2 is a schematic perspective view illustrating the embodiment of FIG. 1 connected to an electric stove, with the detachable key pad magnetically mounted on the stove;

FIG. 3a is a perspective view of the device of the present invention configured for a 120 V electrical appliance, showing the main body from the rear;

FIG. 3b is a perspective view of the main body of FIG. 3a from the front;

FIG. 4 is a perspective view of an alternate embodiment of the present invention having an extension cord;

FIG. 5 is a schematic block diagram of the invention, configured to prevent unauthorized usage of a 220 V appliance, such as an electric stove;

FIG. 6 is a schematic block diagram of the invention, configured to prevent unauthorized usage of a 120 v appliance, such as an electric range or space heater; and

FIG. 7 is a schematic perspective view illustrating an embodiment of the invention utilizing a remote control device.

DETAILED DESCRIPTION OF THE INVENTION

An electrical plug 12 of an appliance 11, in the embodiment illustrated a stove operating on a 220 V household main power supply, is connected to a female socket 19 in a main body 10 of the security power interrupt device for preventing unauthorized usage of an electrical appliance. The interrupt device is in turn plugged into a 220 V wall receptacle 14, which serves as a power supply in this embodiment. In other embodiments, equivalent power supplies may be used which provide electrical energy in a form suitable for use by the electrically operated device that the interrupt device of the invention is used to control.

The electrical circuitry, illustrated in FIG. 5 for a 220 V configuration of the interrupt device, is contained within the main body 10 which serves as a switching component. The interrupt device interrupts the current from the power supply to the appliance 11 when contacts 20 of a relay 33 are opened; the current from the power supply is transferred to the appliance 11 when the contacts 20 of the relay 33 are closed.

In the case of a 220 V appliance, relay contacts 21 are configured in dual-pole single-throw form, so that both voltage-carrying lines L1 and L2 are switched by the relay 33 in the case of an alternative embodiment used in connection with a 120 V appliance, as shown in FIG. 6, contacts 21 of the relay 33 are configured in single-pole single-throw form, so that the voltage-carrying line L is switched by the relay 33. In either configuration, the relay contacts, 20 or 21 must have the appropriate electrical rating for the appliance 11 or other electrically operated device that is used in connection with the invention.

The device for preventing unauthorized usage of an electrical appliance or other electrically operated device in a preferred embodiment, further comprises a DC power supply 25, which generates the direct current (DC) voltages required by a controller which in this embodiment comprises a microcontroller 26; enabling means comprising a manually operable detachable key pad 27; a current transformer 28 with a current transformer shunt 29; a rectifier circuit 30, conventionally comprised of rectifier diode 31 and filter capacitor 32; and means for switching the device between a mode in which power is supplied to the appliance and a mode in which power to the appliance is substantially interrupted comprising a relay 33 having relay coil 34 and contact sets 20 (for the 220 V embodiment of FIG. 5) or 21 (for the 120 V embodiment of FIG. 6).

FIG. 3 shows a preferred embodiment of the present invention for preventing unauthorized use of a 120 V appliance, such as an electric heater or hot plate, by way of example. The main body 10 is in the form of a closed box, directly inserted between wall socket 15 and the appliance plug 13. Thus plug 17 is inserted in wall socket 15, with appliance plug 13 inserted into the socket 19 in the main body 10. Key pad cable 41, which implements the required electrical connections between the detachable key pad 27 and the circuitry in the main body 10 of the device, has a cable connector 42 which can be connected to mating receptacle 43 which together serve as a detachable coupler. Of course, in other embodiments other equivalent devices which are capable of receiving input data and delivering such data to the remainder of the apparatus may be used in place of the key pad. Key pad 27 has a number of entry keys 44 for input of data, as is conventional for such key pads.

In the preferred embodiment for wall mount applications, as shown in FIG. 1, key pad 27 can be mounted to the wall with detachable adhesive material, such as "Velcro" material (trademark), or with more permanent securing means. For appliance mounting applications, as illustrated in FIG. 2, key pad 27 is removably affixed to the metal body of the appliance 11 magnetically, by means of a magnet (not shown) mounted on the rear of the key pad 27.

Key pad 27 is also preferably detachable from the device. The microcontroller 26 monitors the key pad 27 as described below, and when the key pad 27 is detached from the device automatically interrupts power to the appliance 11. This feature can be adapted for use with any power interrupt device provided with conventional logic for monitoring the detachable enabling means component and switching the power interrupt to the interrupt mode when the enabling means component is detached.

FIG. 4 shows an alternate embodiment of the present invention, in which the male plug 17 is extended from the main body 10 by means of a power cord 45, similar to an electrical extension cord.

The embodiments of both FIGS. 3 and 4 are adapted for use with existing appliances, in that the appliance 11 itself does not require any alteration to utilize the device. In other embodiments the invention may be integrated in the electrical wiring of the appliance 11 or into similar electrically operated devices by the manufacturer, prior to sale to the consumer.

The microcontroller 26 of the preferred embodiment is of conventional design, having associated with it one analog input channel 36, on which it can acquire an analog input signal which is roughly proportional to the amount of electrical current drawn by the appliance 11;, one digital output channel 37, through which the microcontroller 26 can control the flow of current from the main power supply to the appliance 11 by energizing or de-energizing relay coil 34; and a key pad input for connection of detachable key pad 27.

Microcontroller 26 is electrically programmed with a software program performing the tasks which are necessary to implement the functions of the interrupt device. The software program in the preferred embodiment is a conventional multi-tasking program approach, with each task implementing a distinct function.

In the case of an electrical appliance such as a stove the software program may preferably perform the following tasks:

1) A first task is a key pad monitoring task for monitoring activity on the key pad 27. When a certain preset sequence of key strokes is input through the key pad, which input key strokes comprise a code, and this code, referred to as the "locking sequence" is received, this task sets the microcontroller to the interrupt or "locked" mode. When another preset sequence of key strokes or code is input through the key pad and is received, referred to as the "unlocking sequence" or alternatively an "authorization code", the key pad monitoring task sets the microcontroller to the operative or "unlocked" mode. The locking and unlocking codes or sequences are only known to authorized persons. If an authorized person switches the device to the operative mode while the relay contacts 20 or 21 are in the open state due to a previous unauthorized attempt to use the appliance 11, the contacts 20 or 21 are closed by degenergizing relay 33 by eliminating the voltage from relay coil 34 through digital output line 37.

The key pad monitoring task supports additional key stroke sequences or codes, in order to configure the microcontroller 26. This permits authorized persons to enter and alter the locking and unlocking sequences; to alter the current threshold at which power interrupt is engaged in the interrupt mode, to alter the "elapsed time threshold" which sets the time interval since the last authorized use following which the interrupt device will automatically enter the interrupt mode, and other system parameters as may be desired.

In addition, this task monitors whether the detachable key pad 27 is connected. When the key pad monitoring task determines that key pad 27 has been disconnected, the microcontroller 26 is automatically set to the interrupt mode. As noted above, this feature can also be applied to other power interrupt devices.

2) A second task is a current monitoring task which monitors the current drawn from the main power supply by acquiring data on analog input channel 36. When this task determines that the current drawn from the main power exceeds a preset limit, referred to as the "current threshold", if this occurs while the microcontroller is in the interrupt mode the current monitoring task will energize relay 33 by applying a voltage to the relay coil 34 through digital output line 37, thus opening relay contacts 20 or 21 and preventing transfer of supply power to the appliance 11. As noted above, when the microcontroller 26 is switched into the operative mode, this task de-energizes the relay 33 by eliminating the voltage from the relay coil 34 through digital output line 37. If the microcontroller 26 is in the operative mode, the current monitoring task monitors the electrical current drawn from the main power supply while the microcontroller 26 remains in the operative mode, in order to determine when to notify the timing task (described below) that the electrical current has been reduced to below the current threshold, and when to notify timing task that the electrical current has exceeded the current threshold.

3) A third task is a timing task. When the microcontroller 26 is in operative mode, and the current monitoring task described above notifies the microcontroller 26 that the electrical current drawn from the main power supply has just been reduced to below the current threshold, the timing task starts to count elapsed time. Similarly, when the microcontroller 26 is in the operative mode, and the timing task is in the process of counting elapsed time, and the current monitoring task notifies the timing task that the current is once more exceeding the current threshold, then the timing task will stop counting elapsed time. When the microcontroller 26 is in the operative mode, and the elapsed time counted by the timing task reaches the "elapsed time threshold" referred to above, the microcontroller 26 will change to the interrupt mode. In addition, when the microcontroller 26 is in operative mode, the timing task implements a timer mode in which the length of time that current can be drawn in excess of the current threshold is limited to a preset time. After this preset time has elapsed, the timing task returns the microcontroller 26 to the interrupt mode, which will immediately cause the current monitoring task to interrupt the main power supply as described above.

The operation of the dev