A) TECHNICAL FIELD
[0001] The embodiments herein generally relates to electrical switching devices and particularly to electromechanically operated switching devices with normally open and normally closed contact system. The embodiments herein more particularly relates to modular contactor assembly with manual override switch for field convertible contact system.
B) BACKGROUND OF THE INVENTION
[0002] An electromechanical device like a contactor or a relay provide a safe and convenient means for switching circuits where requirements demand continuity of a circuit. Conventionally the contactors for motor and general purpose applications are designed with one or more power contacts. An electrical switching device such as an electromagnetic contactor for opening and closing a plurality of switches are well-known. The electrical contacts can be selectively operated to change its function to either normally open or normally closed condition. Certain contactors are designed to employ convertible contact modules which when placed in the contactor in one position provide a normally open switch, and when removed and replaced in a different position provide a normally closed switch. Generally a latch attachment is required to maintain the contacts in either open or closed condition.

[0003] With the switching devices becoming more and more compact, there is a need to provide a manual override switch to operate the contactor mechanically in ON and OFF position. Also there is a need to change the position of the electrical contact from normally open to normally closed condition. In existing contactors the retaining spring is conical in shape and it is placed between the centre limb of stationary and moving electromagnet to disconnect the power supply to the coil during de-energization. This arrangement is complex which demands a simple spring arrangement to disconnect the power supply to the electromechanical coil.
[0004] The conventional field convertible contact structures are complex and occupy more space. Hence there is a need to provide a new arrangement with a compact operating structure. Mostly the end operator is required to arrange the contact configuration according to the requirement before mounting the contact assembly. Hence there is also a need for a mechanism to ensure the contact configuration before and after mounting the contact assembly.
C) OBJECTS OF THE INVENTION
[0005] The primary object of the present invention is to provide a modular contactor assembly with a manual override switch for field convertible contact system to operate the electromagnetic contactor in auto, permanent ON and permanent OFF positions.

[0006] Yet another object of the present invention is to provide a field convertible contact configuration with a normally open and normally closed contact system enclosed in a cassette assembly.
[0007] Yet another object of the present invention is to provide a terminal identification to arrange the contacts in the normally open/normally closed configuration.
[0008] Yet another object of the present invention is to provide a flag indication to identify the position of the contacts in the contactor assembly.
[0009] Yet another object of the present invention is to provide a simple retainer spring arrangement to disconnect the power supply to the electromechanical contactor during de-energization.
[0010] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0011] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specificafion.

[0012] The various embodiments of the present invention provide a modular contactor assembly with a manual override switch for the field convertible contact system to operate the electromagnetic contactor in auto, permanent ON and permanent OFF positions. The electromagnetic contactor assembly according to one embodiment of the present invention includes a manual override switch housing comprising a lever, an actuator and a retaining spring. The housing further includes a fixed electromagnet and an identical moving electromagnet. A coil is wound over a coil former and is enclosed in the housing. The manual override switch housing further includes a pair of moving coil contacts and former contacts. The retainer spring is assembled between the lever and the coil former to retain the moving magnet in its actual position when the coil is de-energized. A manual override switch includes latch2, latch I and latchO to lock the actuator in auto, permanent ON and permanent OFF positions.
[0013] According to one embodiment, the field convertible contact system is mounted at the bottom portion of the manual override switch housing. The manual override switch housing provides space for manual override option at the top with an actuator. The field convertible contact system is enclosed in a cassette assembly. The cassette assembly includes a moving contact housed in the carrier using a contact spring and a fixed contact mounted therein respectively. The movable contact carrier

is connected to the moving magnet of the armature through a connector to actuate the contact between the normally open and normally closed condition of the contactor.
[0014] According to one aspect of the present invention the field convertible contact configuration is enclosed in a cassette assembly so that the operator can arrange the contact configuration according to the requirement before mounting the contact assembly. A terminal identification is also provided in the cassette assembly to identify the contact position from the top of the housing.
[0015] According to one aspect of the present invention, when the actuator is in auto position the moving coil contact in the contactor assembly comes in contact with the former contact to from a closed circuit. When the actuator is moved in forward direction from the auto position, the moving coil contact comes in contact with the former contact. This energizes the coil in the housing and the actuator is locked in the coil former latch to achieve the permanent ON position of the contactor. When the actuator is moved in a backward direction from the auto position, the actuator disconnects the moving coil contact from the former contact. This in turn de-energizes the coil in the housing. This opens the circuit and locks with the latch provided in the coil former to achieve the permanent OFF position of the contactor. Here the end section of the coil is permanently soldered with the former contacts.

i
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0017] FIG. 1 shows a front sectional view and a top view of a normally closed contact system in a cassette assembly, according to one embodiment of the present invention.
[0018] FIG. 2 shows a front sectional view and a top view of a normally open contact system in a cassette assembly, according to one embodiment of the present invention.
[0019] FIG. 3 shows a sectional view of an electromagnetic contactor in auto position with the normally open and normally closed contact system enclosed in the cassette assembly, according to one embodiment of the present invention.
[0020] FIG. 4 shows a sectional view of the electromagnetic contactor in permanent ON position, according to one embodiment of the present invention.
[0021] FIG. 5 shows a sectional view of the electromagnetic contactor in permanent OFF position, according to one embodiment of the present invention.

[0022] FIG. 6 shows an isometric view of the contactor assembly, according to one embodiment of the present invention.
[0023] FIG. 7 shows a top view of the electromagnetic contactor in auto, permanent ON and permanent OFF position, according to one embodiment of the present invention.
[0024] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0025] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

[0026] Various embodiments of the present invention provide a modular electromagnetic contactor assembly with a field convertible contact system. The electromagnetic contactor assembly includes a manual override switch housing with the field convertible contact system to operate the contactor in auto, permanent ON and permanent OFF position. According to one embodiment of the present invention, the normally open and normally closed contact system is enclosed in a cassette assembly 1. FIG. 1 shows a front sectional view and a top view of a normally closed contact system in a cassette assembly 1. With reference to FIG.l, the moving contact 4 is placed in a contact carrier 5 using a contact spring 6 and the fixed contact 3 is placed inside the cassette assembly 1 as shown respectively. A cassette closure cover 2 with a terminal identification 8 is provided to cover the fixed contact 3 and the moving contact 4 in the cassette assembly 1. The cassette closure cover 2 is fixed on the cassette assembly 1 by using a box clamp 7. The terminal identification 8 is provided on the cassette assembly 1 to identify the contact position from the top of the contactor housing.
[0027] FIG. 2 shows a front sectional view and a top view of a normally open contact system in a cassette assembly 1, according to one embodiment of the present invention. The cassette assembly 1 shown in FIG. 1 is tilted 180° upside down to obtain the normally open contact configuration. The normally open cassette arrangement is also provided with a terminal identification 8. The terminal

identification 8 is provided on the bottom portion of the cassette assembly 1. The terminal identification can be viewed from the top of the contactor housing through the transparent means provided on the housing.
[0028] FIG. 3 shows a sectional view of an electromagnetic contactor in auto position with the normally open and normally closed contact system enclosed in the cassette assembly 1, according to one embodiment of the present invention. With respect to FIG.3 the contactor is placed in auto position. The contact positions can be changed by energizing the electromagnetic coil 30. The auto position can be ensured visually by identifying the position of the actuator 9 from the top of the housing 25.
[0029] The electromagnetic contactor assembly includes a manual override switch housing 25 comprising a lever 11, an actuator 9 and a retaining spring 10. The housing 25 further includes an identical fixed electromagnet 13 and a moving electromagnet 14. A coil 30 is wound over a coil former 12 and is enclosed in the housing 25. The retainer spring 10 is assembled between the lever 11 and the coil former 12 to hold the moving magnet 14 to its actual position when the coil 30 is de-energized. The housing 25 further includes a moving coil contact 20, a fixed coil contact 21, and at least one former contact 23 on each side of the coil former 12. In an embodiment of the present invention, a field convertible contact system is mounted at the bottom portion of the manual override switch housing 25 and provides space for manual override option at the top with an actuator 9. The contact

position is changed by energizing the electromagnetic coil 30 in the manual override switch housing 25. The two pole modular contactor with a normally open and normally closed contact configuration is enclosed in the cassette assembly 1. The contact carrier 5 of each pole is connected to the moving magnet 14 using a connector 15. The auto position of the contactor can be ensured visually by the position of the actuator 9 which is locked with the latch2 31 initially.
[0030] In auto position, the moving coil contact 20 comes in contact with the former contact 22 to form a closed circuit. The fixed magnet 13 and moving magnet 14 in the housing 25 are spaced apart from each other. A simple retainer spring 10 is provided to disconnect the power supply to the electromechanical contactor during de-energization and to safeguard the operator working during maintenance activity in industrial or residential areas. An insulation cover 16 is provided above the cassette assembly 1 to resist the flow of electric current. The insulation cover 16 is locked by using an insulation cover lock 17. A terminal screw 18 is provided to assemble the two poled normally open and normally closed contacts in a cassette assembly 1. A box clamp 19 is provided to assemble the contactor housing 25 with the cassette assembly 1.
[0031] FIG. 4 shows a sectional view of the electromagnetic contactor in permanent ON position, according to one embodiment of the present invention. FIG. 4 shows the manual override switch housing 25 including the lever 11, the actuator 9

and the retaining spring 10. Tlie retaining spring 10 is assembled between the lever 11 and the coil former 12. The lever 11 is connected to the contact carrier 5 through connector 15, such that the connector 15 is inserted in the moving armature slot initially. When the actuator 9 is moved in forward direction from the auto position the moving coil contact 20 comes in contact with the former contact 22 to energize the coil 30 in the housing 25.The actuator 9 is locked in the coil former latchl 32 to achieve the permanent ON position of the contactor. When the actuator 9 is moved in the forward direction, the lever 11 connected to the connector 15 pulls the contact carrier 5 such that the contacts come in closed position.
[0032] FIG. 5 shows a sectional view of the electromagnetic contactor in permanent OFF position, according to one embodiment of the present invention. FIG. 5 represents a mechanism with override features indicating the permanent OFF Position of the contactor. When the actuator 9 is pushed in backward direction from the auto position, the connector 15 connected to the contact carrier 5 in the cassette assembly 1 is pushed backwards to achieve the permanent OFF position of the contactor. In OFF position, the actuator disconnects the moving coil contact 20 from the former contact 22 and makes the circuit as open circuited and locks with the latchO 33 provided in the coil former 12. The moving coil contact 20 acts as a leaf spring so that whenever the actuator 9 is moved from OFF to auto position, the moving coil contact 20 comes in contact with the former contact 22 to form a closed

circuit. The end sections of the coil 30 herein are soldered permanently with the former contacts 23.
[0033] FIG. 6 shows an isometric view of the electromagnetic contactor assembly, according to one embodiment of the present invention. FIG. 6 shows the manual override switch housing 25 with an actuator 9 to operate the contactor in automatic, permanent ON and permanent OFF position. The two pole modular contactor with normally open and normally closed contact configuration is enclosed in a cassette assembly 1. The cassette assembly 1 is mounted at the bottom portion of the manual override switch housing 25 and supported by using a cassette base 24. The arrangement provides a manual override option at the top of the housing 25 with an actuator 9. A connecter 15 is shown which connects the contactor carrier 15 of each pole with the lever 11 in the housing 25. A housing screw 26 is provided to mount the cassette assembly 1 with the housing 25. A transparent means such as a fiber glass 29 is provided on the housing 25 to view the markings and to identify the auto, permanent ON and permanent OFF of the contact system.
[0034] FIG. 7 shows a top view of the electromagnetic contactor in auto, permanent ON and permanent OFF position, according to one embodiment of the present invention. FIG. 7 represents the ON position of the electromagnetic contactor. The contact position is changed by energizing the electromagnetic coil 30 in the contactor housing 25. When the coil 30 is energized the actuator 9 moves in

forward direction and tlie moving coil contact 20 comes in contact witli the former contact 23 to energize the coil 30 in the housing 25 and the actuator 9 is locked in the coil former latch 1 to achieve the permanent ON position of the contactor. The terminal marking 8 and the flag indication 28 shows a normally open contact and shows an ON position of the contact system. FIG. 7 further r epresents an auto position of the electromagnetic contactor. In auto position, the moving coil contact 20 comes in contact with the former contact 23 to form a closed circuit and the actuator 9 gets locked in the coil former latch2. The auto position of the contactor is visualized from the position of the actuator 9. The terminal identification 8 and the flag indication 28 show the auto position of the contactor. FIG. 7 thereafter represents a p ermanent OFF position of the electromagnetic contactor. In OFF position, the actuator 9 is moved in a backward direction with respect to the auto position of the actuator 9 to de-energize the coil 30 in the housing 25. The moving coil contact 20 is moved apart from the former contact 23 and simultaneously the electromagnets are moved apart. In OFF position the actuator 9 gets locked in the coil former latchO. The terminal identification 8 and the flag indication 28 shows the permanent OFF position of the contactor.
G) ADVANTAGES OF THE INVENTION
[0035] The various embodiments of the present invention provide a modular contactor with manual override switch for field convertible contact system to operate

the electromagnetic contactor in auto, permanent ON and permanent OFF position. The field convertible contact configuration is enclosed in a cassette assembly so that the operator can arrange the contact configuration according to the requirements before mounting the contact assembly.
[0036] The manufacturing and assembling process of the electrical contacts in the electromagnetic contactors housing is simplified by using the cassette assembly. The terminal identification and the flag indication provided on the cassette assembly provides for identifying the contact closed and contact open position from the top of the housing. The simple design of the retainer spring to disconnect the power supply to the electromechanical contactor during de-energization makes the assembly compact. Also the timely disconnection of the power supply helps to safeguard the operator working during maintenance activity in industrial or residential areas.
[0037] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0038] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and

all the statements of the scope of the invention which as a matter of language might be said to fall there between.

CLAIMS
What is claimed is:
1. A modular contactor assembly with a field convertible contact system, comprising:
A manual override switches housing; An actuator enclosed in the housing; A lever mechanism enclosed in the housing; A retainer spring connected to the actuator and the lever mechanism; A latch provided in the housing;
At least one fixed electromagnet mounted in the housing; At least one moving electromagnet mounted in the housing; A cassette assembly mounted below the manual override switch housing; A contact system enclosed in the cassette assembly; A terminal identification provided in the cassette assembly; and A connector for connecting the contact system with the lever mechanism; Wherein the actuator is reciprocated to operate the electrical contact system in the cassette assembly in automatic, permanent ON and permanent OFF position.
2. The modular contactor assembly according to claim 1, wherein the cassette assembly fiarther includes a contact carrier to hold the contact system.

3. The modular contactor assembly according to claim!, wherein the contact
system includes at least one of a fixed contact and a moving contact.
4. The modular contactor assembly according to claim 1, wherein the auto
position of the actuator provides for abutting the moving coil contact and the
former contact to form a closed circuit.
5. The modular contactor assembly according to claim 1, wherein a shift in
position of the actuator from the auto position in one direction causes the
moving coil contact to come in contact with the former contact to energize
the coil to achieve the permanent ON position.
6. The modular contactor assembly according to claim 1, wherein a shift in the
position of the actuator from auto position in another direction disconnects
the moving coil contact from the former contact to de-energize the coil to
achieve permanent OFF position.
7. The modular contactor assembly according to claim 1, the latch is provided to
lock the actuator in auto, permanent ON and permanent OFF position of the
contactor assembly. j .