A CONTACT SYSTEM AND A SPRING MECHANISM
FIELD OF THE INVENTION
[0001] This invention relates generally to systems for switching electrical currents, and more particularly to, a quad break current interrupting electrical contact apparatus for use in industrial and general electrical equipments.
BACKGROUND OF THE INVENTION
[0002] In general, growing technology in the area of switch application in various
sectors, such as domestic panels, general electric circuits, demand for switching
with single button operation. This provides for much compactness and needed
Aesthetics.
[0003] Conventional contact apparatus have complicated structures for moving
and fixed contacts. Moreover, they are difficult to locate by virtue of their
structure, and also have low endurance as no proper line contact is present
between the contacts.
[0004] Thus, there exists a need for a compact contact apparatus, wherein the
apparatus provides for (i) minimum space occupancy (ii) minimum raw material
wastage during manufacture (iii) easy location of the fixed and movable contacts
(iv) easy entry of moving contacts and ensures proper line contact, and (v)
increased life of the fixed and movable contacts when interrupting current at high
voltages.

SUMMARY OF THE INVENTION
[0005] In an embodiment, an electrical contact apparatus for use in industrial and general electric equipments, comprises at least one housing. The housing accommodates at least one moving contact blade in open closable contact relationship with at least one fixed contact blade for opening or closing current flow therethrough. The moving contact blade has a first main contact portion and the fixed contact blade has a second main contact portion, wherein the first and the second main contact portions are configured having means to draw the arc generated during contact to a location away from the first and the second main contact portions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows an assembled perspective view of the contact apparatus
according to an embodiment of this invention.
[0007] FIG. 2 shows a perspective view of the moving contact assembly
according to an embodiment of this invention.
[0008] FIG. 3 shows an exploded perspective view of the moving contact
assembly according to an embodiment of this invention.
[0009] FIG. 4 shows a perspective view of the moving contact blades and the
fixed contact blades in open relationship with each other according to an
embodiment of this invention.
[0010] FIG. 5 shows a perspective view of the moving contact blades and the
fixed contact blades in closed relationship with each other according to an
embodiment of this invention.
[0011] FIG. 6 shows the fixed contact blade as an example of construction
according to an embodiment of this invention

[0012] FIG. 7 shows the constructional features of the fixed contact blades
according to an embodiment of this invention.
[0013] FIG. 8 shows the exploded view of the constructional features of the fixed
contact blades according to an embodiment of this invention.
[0014] FIG. 9 shows a shows the exploded view of the constructional features of
the moving contact blades according to an embodiment of this invention.
[0015] FIG .10 shows a perspective view of a spring according to an embodiment
of this invention.
[0016] FIG. 11 shows a perspective view of the contact assembly and the arc
formation according to an embodiment of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Various embodiments of this invention provide a contact apparatus such as, a quad break current interrupting electrical contact apparatus for use in industrial and general electrical equipments. The embodiments are not limited and may be implemented in connection with general electric circuits, industrial and domestic electncal panels.
[0018] FIG. 1 shows an assembled perspective view of the contact apparatus according to an embodiment of this invention. Accordingly, the apparatus comprises a moving contact assembly (5) and fixed contact assembly (see FIG. 4 and FIG. 5 details) provided within a housing (1). The moving contact assembly (5) is shown also separately in FIG. 2 and FIG. 3. Referring to FIG. 3, the moving contact assembly (5) comprises at least one moving contact blade (53) configured sandwiched between a front cam (51) and a rear cam (52). In the example shown in FIG. 3, a pair of moving contact blades (53) is provided. [0019] FIG. 4 and FIG. 5 show a perspective view of the moving contact blades (53) and the fixed contact blades (21, 22, 31, 32) in coordinating relationship with

each other. For the purposes of illustration, the fixed contact assembly comprises four fixed contacts designated namely, the upper right fixed contact blade (22), upper left fixed contact (21), lower right fixed contact (32) and lower fixed contact blade (31). At least one contact spring (6) is configured to individually attach on to the fixed contact blades (21,22, 31, 32) to ensure adequate contact pressure. In one embodiment, referring to FIG. 9 the spring (6) has a substantially C-shaped body having arms (6a, 6b, 6c). It should be noted that the C-shaped body enables easy positioning of the spring (6) with the fixed contact blades that will be explained in the later part of this description.
[0020] FIG. 6 shows the fixed contact blade (31) as an example of construction for the purposes of illustration, wherein the fixed contact blade (31) has a substantially zigzag twisted body. The other fixed contact blades (21,22,32) also have a configuration similar to the fixed contact blade (31). All the fixed contact blades (21,22, 31, 32) are made from a common blank material such as, copper, brass etc.
[0021] FIG. 7 and FIG. 8 show the constructional features of the fixed contact blades (21,22, 31, 32) according to an embodiment of this invention. Referring to FIG. 8, the fixed contact blade (31) comprises a zig-zag twisted body having a substantially horizontal portion (31f), a main contact portion (31c) and an inclined portion (31 d) joining the horizontal portion (31f) and the main contact portion (31c). The moving contact blade (53) is configured to come into contact with the main contact portion (31c). The main contact portion (31c) is sufficiently concave to aid in allowing smooth entry of the moving contact blade (53) into the main contact portion (31c). At least one protrusion (31b) Is provided in the main contact portion (31c) to attract the arc formed during current interruption, and move the arc away from the main contact portion (31c). A recess (31a) is provided in the main contact portion (31c) for holding the spring (6). The recess (31a) also acts as a pressure transfer zone for receiving the contact pressure

transferred by the arms (6a, 6b, 6c) of the spring (6) when with the moving contact blade (53) comes into contact with the main contact portion (31c). The horizontal portion (31f) has a termination hole (31e) for fastening the zigzag body of the fixed contact blade (31) on to cable lugs. For example, this may be done penetrating threaded fasteners through the termination hole (31 e) to obtaining proper positioning and tightening torque. The inclined portion (31 d) is sufficiently inclined to position the zig-zag body of the fixed contact blade (31) on to the housing (1). Substantially similar construction is applicable for the other fixed contact blades (21, 22, 32).
[0022]FIG.8 shows a perspective view of the moving contact blade (53) according to an embodiment of this invention. The moving contact blade (53) comprises a substantially W-shaped body having at least a pair of main contact portions (53f) joined by circular central portions (53e, 53d). At least one protrusion (53b) is provided in each main contact portion (53f). The protrusion (53f) is chamfered so as to attract the arc generated during current interruption. Therefore, the life of the main contact portion (53f) is enhanced by minimizing erosion of the main contact portion (53f) due to arcing. The circular central portions (53e, 53d) are profiled to position and secure the moving contact blade (53) in-between the cams (51,52),
[0023] In an embodiment, a cut (53a) is provided in vicinity of the chamfered protrusion (53b) in the main contact portion (53f) to compensate for the increase in cross sectional area of the moving contact blade (53). This prevents heating of the surrounding area of the main contact portion (53f). [0024] The chamfered protrusions (53b) attract the arc towards them saving the main contact portions (53f) from erosion due to arcing during current interruption, thereby increasing the electrical life of the whole system. The cross section Is maintained as uniform as possible, especially by the cuts like (53a) to compensate for the increase in cross section in its vicinity due to the protrusion

(53b) that would otherwise have made the surrounding areas hot. The circular
profiles (53d and 53e) act as locators to secure the moving contacts (53) intact,
between the cams (51 and 52)
[0025] FIG .10 shows an embodiment wherein during interruption, the arcing
zone are far off from the main contact portions of the moving contact blades (53)
and the fixed contact blades (21, 22, 31, 32),
[0026] Thus, various specific embodiments provide an electrical contact
apparatus and a switch mechanism thereof. The embodiments may be modified
which may be obvious to a person skilled in the art. However all such
modifications are deemed to be within the scope of the claims claimed herein:

We Claim:
1. An electrical contact apparatus, comprising:
(i) at least one housing;
(ii) said housing accommodating at least one moving contact blade in open closable contact relationship with at least one fixed contact blade for opening or closing current flow therethrough;
(iii) said moving contact blade having a first main contact portion;
(iv) said fixed contact blade having a second main contact portion, wherein the first and the second main contact portions are configured having means to draw the arc generated during contact to a location away from the first and the second main contact portions.
2. An electrical contact apparatus as claimed in claim 1 wherein the means includes a first chamfered protrusion configured in the first main contact portion.
3. An electrical contact apparatus as claimed in claim 1 wherein the means includes a second protrusion configured in the second main contact portion.
4. An electrical contact apparatus as claimed in claim 1 wherein the second main contact portion is configured having a concave surface so as to allow substantial smooth entry of the first main contact portion into the second main contact portion.
5. An electrical contact apparatus as claimed in claim 1 wherein the first main contact portion has a cut section whose cross section corresponds to that of the chamfered protrusion.
6. An electrical contact apparatus as claimed in claim 1 wherein the fixed contact blade comprises a zig-zag twisted body having a substantially horizontal portion joined to the second main contact portion through an inclined portion.

7. An electrical contact apparatus as claimed in claim 1 further comprising a c-shaped spring to receive and transmit the contact pressure from the moving contact blade to the fixed contact blade.
8. An electrical contact apparatus as claimed in claim 7 wherein the c-shaped spring comprises at least a pair of arms.
9. An electrical contact apparatus as claimed in claim 1 wherein the fixed contact blades further comprises at least one recess wherein the arms are positioned within the recess.
10. An electrical contact apparatus as claimed in claim 6 wherein the zigzag body is positioned and secured to the housing through the inclined portion.