Title of Invention	KEY FOR LOCKING THE CONTACTORS IN ON CONDITION
Abstract	[0020] A Key locking system for contactors in ON condition. Contactor is locked in ON condition with the help of the key. Now the supply to the electromagnet can be switched off. With the help of key locking system in ON condition, contactor continues to remain in ON condition in spite of no supply in the control circuit. This process saves loss of energy in the control circuit since locking system continues to hold the contactor in ON condition. The key is assembled manually once contactor is in energized condition.

Title of Invention

KEY FOR LOCKING THE CONTACTORS IN ON CONDITION

Abstract

[0020] A Key locking system for contactors in ON condition. Contactor is locked in ON condition with the help of the key. Now the supply to the electromagnet can be switched off. With the help of key locking system in ON condition, contactor continues to remain in ON condition in spite of no supply in the control circuit. This process saves loss of energy in the control circuit since locking system continues to hold the contactor in ON condition. The key is assembled manually once contactor is in energized condition.

Full Text	FORM 2 THE PATENTS ACT, 1970 PROVISIONAL SPECIFICATION (See Section 10) KEY FOR LOCKING THE CONTACTORS IN ON CONDITION Numbered as dated INVENTORS: a) VINOD M.. PANCHAL APPLICANT: M/s. LARSEN & TOUBRO LIMITED L&T House, Ballard Estate, P.O. Box No 278, Mumbai, 400 001, Maharashtra, INDIA 1 THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THE INVENTION KEY FOR LOCKING THE CONTACTORS IN ON CONDITION A) Technical field [0001] The embodiments herein generally relate to electromagnetic switching device, and more specifically to locking system for locking the contactor in ON condition. B) Background [0002] A contactor is an electrical device used for switching a power circuit. Contactors come in many forms with varying capacities and features. Contactors are used to control electric motors, lighting, heating, capacitor banks, and other electrical loads. [0003] A contactor is composed of three different systems named as contact system, electromagnetic system and enclosure system. The contact system is the current carrying part of the contactor. This includes power contacts, auxiliary contacts and contact springs. An electromagnet system provides the driving force to close the contacts. The enclosure system is a frame housing the contact and the electromagnet. A basic contactor has a coil input (which may be driven by either an AC or DC supply depending on the contactor design) and generally a minimum of two poles which are controlled. 3 [0004] Contactors are energized through electromagnet and then held in position by continuously supplying the coil through the power source. This means a continuous power loss in control circuit. In order to overcome this problem many method have been introduced. Specially designed latched contactor is one of the prior methods developed for the same. However, those contactors do not require manual intervention. Electrical signals are required to switch on and off the contactors. [0005] While the conventional solutions are advantageous for their intended purposes, the existing state of the art generally does not provide adequate solutions to overcome the power loss in control circuit. [0006] Hence, there is a need to develop a system that can provide a locking system for a contactor in ON condition and save loss of energy in the control circuit. C) Object of the Invention [0007] An object of the invention is to provide locking system for a contactor in ON condition. [0008] Another object of the invention is to provide a system that saves loss of energy in the control circuit. 4 D) Summary [0009] The embodiments herein provide a locking system for contactors in ON condition. Contactors are energized through electromagnet and then held in position by continuously supplying the coil through the power source. This leads to a continuous power loss in control circuit. In the present embodiment a key is used for locking the contactors. Using this innovative key contactor can be locked / latched in ON condition. Now the supply to the electromagnet can be switched off. With the help of key locking system in ON condition, contactor continues to remain in ON condition in spite of no supply in the control circuit. This process saves loss of energy in the control circuit since locking system continues to hold the contactor in ON condition. The key is assembled manually once contactor is in energized condition. Switching off the contactor is also done manually. [0010] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications. 5 E) Brief description of the drawings [0011] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which: [0012] FIG. 1 illustrates key used in locking system according to an embodiment herein; [0013] FIG. 2 illustrates key locking assembly for contactor; [0014] FIG. 3 illustrates overall locking assembly when contactors are in the locked position. F) Detailed description of the Invention [0015] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as 6 limiting the scope of the embodiments herein. [0016] FIG. 1 illustrates key used in locking system according to an embodiment herein. Key is designed as shown in the figure and is main component of locking assembly. The key is assembled manually once contactor is in energized condition. Switching off the contactor is also done manually. [0017] FIG. 2 illustrates key locking assembly for contactor. Contactors are energized through electromagnet and then held in position by continuously supplying the coil through the power source. This leads to a continuous power loss in control circuit. A key is used in the present embodiment for locking the contactors. Using this innovative key contactor can be locked / latched in ON condition. [0018] FIG. 3 illustrates overall locking assembly when contactors are in the locked position. Using the key contactor is locked / latched in ON condition. Now the supply to the electromagnet can be switched off. With the help of key locking system in ON condition, contactor continues to remain in ON condition in spite of no supply in the control circuit. This process saves loss of energy in the control circuit since locking system continues to hold the contactor in ON condition. [0019] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various 7 applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims. The detailed scope and monopoly of the invention shall be more clearly ascertained at the time of filing Complete Specification Dated this the 28 day of March, 2007 Rakesh Prabhu, Patent Agent, ALMT Legal, No.2, Lavelle Road, Bangalore-560 001, INDIA To, The Controller of Patents, The Patent office, At Mumbai 8 Abstract [0020] A Key locking system for contactors in ON condition. Contactor is locked in ON condition with the help of the key. Now the supply to the electromagnet can be switched off. With the help of key locking system in ON condition, contactor continues to remain in ON condition in spite of no supply in the control circuit. This process saves loss of energy in the control circuit since locking system continues to hold the contactor in ON condition. The key is assembled manually once contactor is in energized condition. 9

Full Text

FORM 2
THE PATENTS ACT, 1970 PROVISIONAL SPECIFICATION
(See Section 10)
KEY FOR LOCKING THE CONTACTORS IN ON CONDITION
Numbered as dated
INVENTORS:
a) VINOD M.. PANCHAL
APPLICANT:
M/s. LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No 278,
Mumbai, 400 001, Maharashtra,
INDIA
1

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
NATURE OF THE INVENTION

KEY FOR LOCKING THE CONTACTORS IN ON CONDITION
A) Technical field
[0001] The embodiments herein generally relate to electromagnetic switching device, and more specifically to locking system for locking the contactor in ON condition.
B) Background
[0002] A contactor is an electrical device used for switching a power circuit. Contactors come in many forms with varying capacities and features. Contactors are used to control electric motors, lighting, heating, capacitor banks, and other electrical loads.
[0003] A contactor is composed of three different systems named as contact system, electromagnetic system and enclosure system. The contact system is the current carrying part of the contactor. This includes power contacts, auxiliary contacts and contact springs. An electromagnet system provides the driving force to close the contacts. The enclosure system is a frame housing the contact and the electromagnet. A basic contactor has a coil input (which may be driven by either an AC or DC supply depending on the contactor design) and generally a minimum of two poles which are controlled.
3

[0004] Contactors are energized through electromagnet and then held in position by continuously supplying the coil through the power source. This means a continuous power loss in control circuit. In order to overcome this problem many method have been introduced. Specially designed latched contactor is one of the prior methods developed for the same. However, those contactors do not require manual intervention. Electrical signals are required to switch on and off the contactors.
[0005] While the conventional solutions are advantageous for their intended purposes, the existing state of the art generally does not provide adequate solutions to overcome the power loss in control circuit.
[0006] Hence, there is a need to develop a system that can provide a locking system for a contactor in ON condition and save loss of energy in the control circuit.
C) Object of the Invention
[0007] An object of the invention is to provide locking system for a contactor in ON condition.
[0008] Another object of the invention is to provide a system that saves loss of energy in the control circuit.
4

D) Summary
[0009] The embodiments herein provide a locking system for contactors in ON condition. Contactors are energized through electromagnet and then held in position by continuously supplying the coil through the power source. This leads to a continuous power loss in control circuit. In the present embodiment a key is used for locking the contactors. Using this innovative key contactor can be locked / latched in ON condition. Now the supply to the electromagnet can be switched off. With the help of key locking system in ON condition, contactor continues to remain in ON condition in spite of no supply in the control circuit. This process saves loss of energy in the control circuit since locking system continues to hold the contactor in ON condition. The key is assembled manually once contactor is in energized condition. Switching off the contactor is also done manually.
[0010] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
5

E) Brief description of the drawings
[0011] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
[0012] FIG. 1 illustrates key used in locking system according to an embodiment herein;
[0013] FIG. 2 illustrates key locking assembly for contactor;
[0014] FIG. 3 illustrates overall locking assembly when contactors are in the locked position.
F) Detailed description of the Invention
[0015] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as
6

limiting the scope of the embodiments herein.
[0016] FIG. 1 illustrates key used in locking system according to an embodiment herein. Key is designed as shown in the figure and is main component of locking assembly. The key is assembled manually once contactor is in energized condition. Switching off the contactor is also done manually.
[0017] FIG. 2 illustrates key locking assembly for contactor. Contactors are energized through electromagnet and then held in position by continuously supplying the coil through the power source. This leads to a continuous power loss in control circuit. A key is used in the present embodiment for locking the contactors. Using this innovative key contactor can be locked / latched in ON condition.
[0018] FIG. 3 illustrates overall locking assembly when contactors are in the locked position. Using the key contactor is locked / latched in ON condition. Now the supply to the electromagnet can be switched off. With the help of key locking system in ON condition, contactor continues to remain in ON condition in spite of no supply in the control circuit. This process saves loss of energy in the control circuit since locking system continues to hold the contactor in ON condition.
[0019] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various
7

applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
The detailed scope and monopoly of the invention shall be more clearly ascertained at the time of filing Complete Specification
Dated this the 28 day of March, 2007

Rakesh Prabhu,
Patent Agent, ALMT Legal,
No.2, Lavelle Road, Bangalore-560 001, INDIA
To,
The Controller of Patents,
The Patent office,
At Mumbai
8

Abstract
[0020] A Key locking system for contactors in ON condition. Contactor is locked in ON condition with the help of the key. Now the supply to the electromagnet can be switched off. With the help of key locking system in ON condition, contactor continues to remain in ON condition in spite of no supply in the control circuit. This process saves loss of energy in the control circuit since locking system continues to hold the contactor in ON condition. The key is assembled manually once contactor is in energized condition.
9

Documents:

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Patent Number

270132

Indian Patent Application Number

644/MUM/2007

PG Journal Number

49/2015

Publication Date

04-Dec-2015

Grant Date

30-Nov-2015

Date of Filing

30-Mar-2007

Name of Patentee

LARSEN & TOUBRO LIMITED

Applicant Address

L&T HOUSE, BALLARD ESTATE, P.O.BOX NO,278, MUMBAI

Inventors:

#	Inventor's Name	Inventor's Address
1	VINOD PANCHAL	SWITCHGEAR DESIGN & PRODUCT DEVLOPMENT CENTER, LARSEN & TOUBRO LIMITED, ELECTRICAL SECTOR-(EBG), POWAI WORKS (EAST), GATE NO.7 SAKI VIHAR ROAD, MUMBAI 400072

PCT International Classification Number

H01H50/18

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA