DESC:TECHNICAL FIELD OF THE INVENTION
The present invention relates to the rescue devices for elevators and more particularly, to automatic rescue device for jerk-less rescue operation.

BACKGROUND OF THE INVENTION
Automatic rescue devices are the temporary power supply to the elevator or any other machine during sudden power failure during the machine in motion or operation. It provides a very limited power supply to the machine till it reaches to safe level or nearest destination and it gets totally discharged.
Conventional ARD systems are offline systems, wherein, during the event of power failure, the running elevator stops instantly which introduces a high jerk in the elevator. Moreover, lights and fans turn off and ultimately passengers in the elevator have to face the sudden panic situation. In addition to that, other components of the lifts are prone to damage due to high feed-back power generation because of sudden application of breaks.
The current state of art includes the elevator system having ARD device. Such systems are prone to apply sudden breaks in case if power-outage and build panic in the passengers inside the lift. The current systems include the ARDs that work in offline configuration thereby delaying to switch on the inverter in case of power failure
Accordingly, there is need of a device that eliminates jerk or delay in an event of power failure to the start of the auto rescue operation.

SUMMARY OF THE INVENTION
The present invention provides a device for jerk-less rescue operation for an elevator. The device is powered by a three phase power supply connected to an elevator control panel. The device includes a charger connected to a plurality of rechargeable batteries. The rechargeable batteries are connected to an inverter. The inverter is connected to a power supply and sensing circuit unit. The power supply and sensing circuit unit is adapted to sense the power failure in each of the phases of the three phase input is connected to a switch gear.
In another aspect a method for the device for jerk-less rescue operation is provided. Initially, a power failure is detected by the power supply & sensing circuit unit. In the next step, the inverter is actuated by the power supply & sensing circuit unit thereby supplying power to a switch gear connected thereto. In the next step, power is generated in the inverter at pick voltage thereby reducing the loss of power. In the next step, generated power is switched from the inverter to the switch gear by the power supply & sensing circuit unit in a predetermined response time thereby keeping the elevator movement seamless. In the last step, The elevator control panel is energized with 2-Phase power thereby running a motor in the Up/Down direction at low speed that brings an elevator to an immediate next/earlier floor.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an environmental diagram of the system in accordance with an embodiment of the present invention;
FIG. 2 shows layout diagram of an automatic rescue device of the system of FIG. 1; and
FIG. 3 shows schematic diagram of working of the automatic rescue device of the system of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.
In general aspect, the present invention discloses an automatic rescue device for jerk-less rescue operation. The device turns ON the inverter in case of power failure in no time thereby eliminating the jerk and black out in the elevators.
References in the specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
Referring to FIG. 1, an automatic rescue device (100) (hereinafter “the device”) in accordance with an embodiment of the present invention is shown. The device (100) is connected to an elevator control panel (200). The device (100) is powered with three phase mains supply. The device (100) provides three phase output to the elevator control panel (200) in normal condition. In case of power failure, the device (100) switches to an inverter (135) and provides 2 phase power to a switch gear (140).
Referring to FIGS. 2 and 3, the device (100) includes a plurality of terminals (105), a charger (110), a plurality of rechargeable batteries (120), the inverter (135), the switch gear (140), a phase detection unit (145), a relay (150), a display (160) and a transformer (180). The terminals (105) are provided for connecting input / output power supply with safety inputs. The charger (110) is connected to the rechargeable battery (120). The rechargeable batteries (120) are connected to the inverter (135). The inverter (135) is monitored by a power supply & sensing circuit unit (170). The power supply & sensing circuit unit (170) is also connected to a switch gear (140). The relays (150) are used to drive the switch gear (140) components. The display (160) shows the battery voltage, current and AC voltage generated for monitoring purpose.
Referring to FIGS. 1-3, in operation, in case of uninterrupted normal power supply, the main power is supplied to the charger (110), the power supply & sensing circuit unit (170), and the switch gear (140). In this case the charger (110) keeps charging the rechargeable batteries (120) that receive power from the charger (110). The switch gear (140) uses mains power to control the elevator. The power supply & sensing circuit unit (170) is adapted to sense the power failure in each of the phases of the three phase input. The power supply & sensing circuit unit (170) is connected to the inverter (135).
In accordance with the present invention, the power failure is detected within half cycle by the power supply & sensing circuit unit (170). In such case, the power supply & sensing circuit unit (170) actuates the inverter (135) to supply power to the switch gear (140) in no time. Power generation starts in the inverter (135) at pick voltage which reduces the loss of power. The power supply & sensing circuit unit (170) switches power to the switch gear (140) from the inverter (135) in a predetermined response time thereby keeping the elevator movement seamless. The transformer (180) generates the required higher AC voltage from a low AC voltage generated by the inverter (135). In this one embodiment, the response time is in approximately 15 milliseconds and availability of full power within 20 milli seconds or 1 AC cycle. However, it is understood here that response time may vary in alternative embodiments of the present invention.
.The operation of sensing the power failure and transmission of signals from the power supply & sensing circuit unit (170) switches power to the switch gear (140) from the inverter (135) takes place by a electronic or software programme. However, it is understood here that signals may be communicated for completion of the operation through pneumatic, electromechanical or any other suitable mechanism.
In accordance with this one embodiment, the inverter (135) may produce and supply 2-Phase, 450V, sinusoidal power to the elevator control panel (200). The elevator control panel (200) gets energized with 2-Phase power, runs a motor in the Up/Down direction at low speed and brings the elevator to an immediate next/earlier floor and opens the door automatically. Upon opening the doors, the trapped passengers exit and the device (100) actuates the elevator control panel (200) to shut the inverter (135) to prevent any further battery drain. However, it is understood here that as the normal power resumes, the device (100) automatically switches the elevator control panel (200) for normal operation.
The device (100) of the present invention facilitates jerk free operations of the elevators and eliminates black out even for few seconds thereby maintaining the lights in the elevator. The device (100) facilitates air circulation inside the elevator through a fan or blower in case of power failure. The device (100) switches from main power supply to inverter power in almost no time. The device (100) has built-in minimum set of lightweight maintenance free batteries (120) that reduces weight and need of maintenance. In this one embodiment, it requires just 4 batteries of 7AH to operate the 5 HP motor. The device (100) of the present invention cuts off the power sourcing from the battery as soon as the main power supply comes in to action in order to prevent from the over draining.
The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.
,CLAIMS:
1. A device (100) for jerk-less rescue operation, the device (100) powered by a three phase power supply connected to an elevator control panel (200), the device (100) comprising:
a charger (110) connected to a plurality of rechargeable batteries (120);
the rechargeable batteries connected to an inverter (135); wherein
the inverter (135) is connected to a power supply and sensing circuit unit (170); and
the power supply and sensing circuit unit (170) adapted to sense the power failure in each of the phases of the three phase input is connected to a switch gear (140).

2. The device (100) for jerk-less rescue operation as claimed in claim 1, wherein the power failure is detected within half cycle by the power supply & sensing circuit unit (170).

3. The device (100) for jerk-less rescue operation as claimed in claim 1, wherein the inverter (135) produces and supplies 2-Phase, 450V, sinusoidal power to the elevator control panel (200).

4. The device (100) for jerk-less rescue operation as claimed in claim 1, wherein the switch gear (140) is driven by a relay (150).

5. A method for the device (100) for jerk-less rescue operation as claimed in claim 1 comprising the steps of:
detecting a power failure by the power supply & sensing circuit unit (170);
actuating an inverter (135) by the power supply & sensing circuit unit (170) thereby supplying power to a switch gear (140) connected thereto;
generation of power in the inverter (135) at pick voltage thereby reducing the loss of power;
switching the generated power from the inverter (135) to the switch gear (140) by the power supply & sensing circuit unit (170) in a predetermined response time thereby keeping the elevator movement seamless; and
energizing an elevator control panel (200) with 2-Phase power thereby running a motor in the up or down direction at low speed that brings an elevator to an immediate next or earlier floor.

6. The method for the device (100) for jerk-less rescue operation as claimed in claim 5, wherein the device (100) is connected to the elevator control panel (200).

7. The method for the device (100) for jerk-less rescue operation as claimed in claim 5, wherein the response time is in approximately 15 milliseconds.

8. The method for the device (100) for jerk-less rescue operation as claimed in claim 5, wherein full power is made available within 20 milli seconds or 1 AC cycle.