CLIAMS:We Claim:

1. A modular changeover contactor assembly (100) for switching devices, the modular changeover contactor assembly (100) comprising:
a first contact system (20) and a second contact system (40), the first contact system (20) having a first fixed contact (5), a first moving contact (10) and a first contact bridge (15), the second contact system (40) having a second fixed contact (25), a second moving contact (30) and a second contact bridge (35), the moving contacts (10, 30) being connected to contact bridges (15, 35), the moving contacts (10, 30) engage and disengage with the fixed contacts (5, 25) in ON and OFF positions of the contact systems (20, 40), wherein the first contact system (20) and the second contact system (40) are integrated as a single unit;
a changeover mechanism (60) having,
a first hook (45) connected to the first contact bridge (15), the first hook (45) capable of being actuated by a first solenoid,
a second hook (50) connected to the second contact bridge (35), the second hook (50) capable of being actuated by a second solenoid, and
an in-built interlocking means positioned on the hooks (45, 50) to ensure closing of any one of the first contact system (20) and the second contact system (40) at a time; and
an electromagnet system (80) having a fixed magnet (65) and a moving magnet (70) connected to the first hook (45) and the second hook (50) via a coupler link (75) and compression springs connected to the moving magnet (70),
wherein, in ON position of the first contact system (20), a trigger signal to the first solenoid decouples the second hook (50) from the coupler link (75) and ensures coupling of the coupler link (75) only with the first hook (45) causing the fixed magnet (65) to attract the moving magnet (70) and the coupler link (75) that in turn moves the first contact bridge (15) in a downward direction causing the first moving contact (10) coupled to the first contact bridge (15) to establish an electrical connection with the first fixed contact (5),
wherein, in ON position of the second contact system (40), a trigger signal to the second solenoid decouples the first hook (45) from the coupler link (75) and ensures coupling of the coupler link (75) only with the second hook (50) causing the fixed magnet (65) to attract the moving magnet (70) and the coupler link (75) that in turn moves the second contact bridge (35) in a downward direction causing the second moving contact (30) coupled to the second contact bridge (35) to establish an electrical connection with the second fixed contact (25).

2. The modular changeover contactor assembly (100) as claimed in claim 1, wherein the coupler link (75) includes fixing means (77A, 77B) configured thereon, the fixing means (77A, 77B) allows engagement and disengagement of the hooks (45, 50) with the coupler link (75).
,TagSPECI:Field of the invention

The present invention relates generally to switching devices and more particularly, to a modular changeover contactor assembly for the switching devices.

Background of the invention

In the prior art it is generally known that an opening of an electrical circuit is achieved when both contactors/ contact systems of a switching device are in OFF positions while closing is achieved when the contactors are in ON positions.

Reference may be made to US patent US4513269 that discloses a contactor assembly comprising a case having a plurality of serially and vertically sectioned pole chambers, each provided with a traveling contact and a pair of operation frames. A traveling contact bar having right and left arm portion is pivotally fixed on a support frame. The operation frames are installed at right and left positions of the traveling contact and each frame is provided with a window and a leg portion extending from a lower surface of the frame. A pair of upper and lower contact springs is provided in the window and the adjacent arm portion of the traveling contact extends through the window and is sandwiched by the pair of contact springs. The pair of right and left operation frames is interlockingly connected at the lower ends of both the legs. An electromagnet is connected to each leg and a return spring is provided on the lower surface of the frame. At least one traveling contact terminal is provided at each tip of the arm portions of the traveling contact bar and a stationary contact terminal is provided in the path of the traveling contact terminals. At least one connecting terminal is provided at each side of the pole chamber.

However, the above mentioned invention uses two different electromagnets for switching ON of the contactors. The use of two electromagnets and interlocks increases the overall cost of the switching device. Further, the contactors of the prior art are designed as a single unit or as 2 pole, 3 pole and 4 pole products that adopt different designs requiring huge investment for individual product development.

Accordingly, there is a need of a modular changeover contactor assembly for switching devices that overcomes the above mentioned drawbacks of the prior art.

Objects of the invention

An object of the present invention is to integrate two contact systems into a single unit.

Another object of the present invention is to provide a common actuating means for two contact systems.

Yet another object of the present invention is provide contactors that are capable of adapting to a design with any number of poles thereby providing a simple, cost-effective and reliable solution in choosing contactors for varied applications.

One more object of the present invention is to provide a changeover mechanism with an in-built interlocking means.

Summary of the invention

Accordingly, the present invention provides a modular changeover contactor assembly (hereinafter “the assembly”) for switching devices. The assembly comprises a first contact system, a second contact system, a changeover mechanism and an electromagnet system.
The first contact system and the second contact system are integrated as a single unit. The first contact system comprises a first fixed contact, a first moving contact and a first contact bridge. The second contact system comprises a second fixed contact, a second moving contact and a second contact bridge. The moving contacts are connected to contact bridges. The moving contacts engage and disengage with the fixed contacts in ON and OFF positions of the contact systems.

The changeover mechanism comprises a first hook, a second hook and an in-built interlocking means. The first hook is connected to the first contact bridge and gets actuated by a first solenoid. The second hook is connected to the second contact bridge and gets actuated by a second solenoid. The in-built interlocking means is positioned on the hooks to ensure closing of only one contact system at a time.

The electromagnet system comprises a fixed magnet, a moving magnet connected to the first hook and the second hook via a coupler link and compression springs connected to the moving magnet. The coupler link includes fixing means configured thereon. The fixing means allows engagement and disengagement of the hooks with the coupler link.

In ON position of the first contact system, a trigger signal to the first solenoid decouples the second hook from the coupler link and ensures coupling of the coupler link only with the first hook causing the fixed magnet to attract the moving magnet and the coupler link that in turn moves the first contact bridge in a downward direction causing the first moving contact coupled to the first contact bridge to establish an electrical connection with the first fixed contact.

In ON position of the second contact system, a trigger signal to the second solenoid decouples the first hook from the coupler link and ensures coupling of the coupler link only with the second hook causing the fixed magnet to attract the moving magnet and the coupler link that in turn moves the second contact bridge in a downward direction causing the second moving contact coupled to the second contact bridge to establish an electrical connection with the second fixed contact.

Brief description of the drawings

Figure 1 shows a three dimensional view of a modular changeover contactor assembly for switching devices, in accordance with the present invention;

Figure 2 is a front view of the modular changeover contactor assembly for switching devices showing contact systems in OFF position, in accordance with the present invention;

Figure 3 is a side view of the modular changeover contactor assembly for switching devices showing contact systems in OFF position, in accordance with the present invention;

Figure 4 is a side view of the modular changeover contactor assembly for switching devices showing a first contact system in ON position, in accordance with the present invention; and

Figure 5 is a side view of the modular changeover contactor assembly for switching devices showing a second contact system in ON position, in accordance with the present invention.

Detailed description of the invention

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

The present invention provides a modular changeover contactor assembly (hereinafter “the assembly”) for switching devices. The assembly comprises a first contact system and a second contact system integrated as a single unit with a changeover mechanism therebetween. The assembly uses a common electromagnetic system for the first contact system and the second contact system. The assembly enables achieving pole-wise modularity for the contact systems and prevents simultaneous switching ON of both the contact systems. The assembly is useful in changeover applications such as a diesel-generator set where switching between sources is required.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring to figures 1-5, a modular changeover contactor assembly (100) (hereinafter “the assembly (100)”) for switching devices (not shown) in accordance with the present invention is shown. The assembly (100) comprises a first contact system (20), a second contact system (40), a changeover mechanism (60) and an electromagnet system (80).

The contact systems (20, 40) are capable of switching between ON and OFF positions. The default state of the contact systems (20, 40) is OFF. The first contact system (20) and the second contact system (40) are connected to two different power supplies (not shown) and the changeover mechanism (60) linked therebetween is capable of switching from the first contact system (20) to the second contact system (40) based on respective coil supply (not shown).

The first contact system (20) comprises a first fixed contact (5), a first moving contact (10) and a first contact bridge (15). The second contact system (40) comprises a second fixed contact (25), a second moving contact (30) and a second contact bridge (35). The moving contacts (10, 30) engage and disengage with the fixed contacts (5, 25) in ON and OFF positions of the contact systems (20, 40). In OFF position of the contact systems (20, 40), the moving contacts (10, 30) are separated from the fixed contacts (5, 25) by contact gaps (not numbered). The moving contact (10, 30) and the fixed contact (5, 25) are connected to the respective contact bridges (15, 35). In an embodiment, the first contact system (20) and the second contact system (40) are integrated as a single unit.

The changeover mechanism (60) comprises a first hook (45) and a second hook (50). The first hook (45) is connected to the first contact bridge (15) by a first coupler pin (55A). The second hook (50) is connected to the second contact bridge (35) by a second coupler pin (55B). The connectivity of the hooks (45, 50) and the coupler pins (55A, 55B) with the bridges (15, 35) enables a pole-wise modularity. The first hook (45) and the second hook (50) are actuated using a first solenoid (not shown) and a second solenoid (not shown). The changeover mechanism (60) further comprises an in-built interlocking means (not shown) positioned on the hooks (45, 50) to ensure closing of only one contact system (20/40) at a time. In an embodiment, the assembly (100) can be converted into a stand-alone single contactor assembly by removing the second contact system (40) and the second hook (50).

The electromagnet system (80) comprises a fixed magnet (65) and a moving magnet (70). The moving magnet (70) includes compression springs (not shown) attached thereto. The moving magnet (70) is connected to the first hook (45) and the second hook (50) via a coupler link (75). The coupler link (75) includes fixing means (77A, 77B) configured thereon. The fixing means (77A, 77B) allow engagement and disengagement of the hooks (45, 50) with the coupler link (75). The electromagnet system (80) is actuated by the coil supply (not shown).

Referring to figure 3, the contact systems (20, 40) in OFF positions, in accordance with the present invention is shown. In the OFF position, the fixed contacts (5, 25) and the moving contacts (10, 30) of the contact systems (20, 40) are separated by the contact gaps. In the OFF position, the whole assembly (100) enters in a stable state by suspension of the compression springs connected to the moving magnet (70). In the OFF position, an electrical continuity is absent on both the contact systems (20, 40) and both the hooks (45, 50) are coupled to the coupler link (75). Depending on the actuation of the solenoids on the hooks (45, 50), any one of the first contact system (20) and the second contact system (40) is turned ON. The in-built interlocking means on the hooks (45, 50) ensures closing of only one contact system (20/40) at a time.

Now referring to figure 4, the first contact system (20) in ON position, in accordance with the present invention is shown. In this position, a trigger signal to the first solenoid decouples the second hook (50) from the coupler link (75) and ensures coupling of the coupler link (75) only with the first hook (45). Subsequently, the fixed magnet (65) attracts the moving magnet (70). The coupler link (75) being connected to the moving magnet (70) moves therewith in a downward direction. The movement of the coupler link (75) along with the moving magnet (70) in the downward direction causes the first contact bridge (15) to move in the downward direction. The first moving contact (10) being coupled to the first contact bridge (15) also moves downward to establish an electrical connection with the first fixed contact (5).

Referring to figure 5, the second contact system (40) in ON position, in accordance with the present invention is shown. In this position, a trigger signal to the second solenoid decouples the first hook (45) from the coupler link (75) and ensures coupling of the coupler link (75) only with the second hook (50). Subsequently, the fixed magnet (65) attracts the moving magnet (70). The coupler link (75) being connected to the moving magnet (70) moves therewith in a downward direction. The movement of the coupler link (75) along with the moving magnet (70) in the downward direction causes the second contact bridge (35) to move in the downward direction. The second moving contact (30) being coupled to the second contact bridge (35) also moves downward to establish an electrical connection with the second fixed contact (25).

Advantages of the invention

1. The assembly (100) facilitates pole-wise modularity in the contact systems (20, 40) thereby deriving 2 pole, 3 pole and 4 pole designs thereof.
2. The assembly (100) is compact as the first contact system (20) and the second contact system (40) are integrated as a single unit with the changeover mechanism (60) positioned therebetween.
3. The assembly (100) uses common electromagnetic system (80) for the first contact system (20) and the second contact system (40).
4. The assembly (100) provides low cost and reliable changeover contactors with minimal investment to market for varied applications like the diesel-generator set.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and 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 omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.