TECHNICAL FIELD
The subject matter described herein, in general, relates to an overcurrent tripping adjuster mechanism and in particular, relates to a magnetic overcurrent tripping adjuster mechanism for circuit breakers.
BACKGROUND
A circuit breaker provides overcurrent protection for residential, commercial and industrial electrical circuits. A circuit breaker is designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect overcurrent in the circuit, and interrupt current flow & such an interruption is caused by mechanism, the intelligence part of a circuit breaker. The circuit breaker can be reset to resume normal operation.
Since the circuit breakers are used in a variety of application areas such as residential, commercial and industrial, the overcurrent value/overcurrent definition varies widely. In order to cater such a varying trend in overcurrent value and consequently the tripping of circuit breaker, overcurrent tripping adjustment mechanisms are required.
Various overcurrent tripping adjustment mechanisms are known in the art for the purpose of adjusting overcurrent value required to interrupt the current flow in the circuit. Such overcurrent tripping adjustment mechanisms rely on horizontal movement of an adjusting bar for the change in force required to be overcome by the tripping mechanism to break the circuit. Further, the existing overcurrent tripping adjustment mechanisms are generally complex in construction and require large space for installation. Furthermore, the processing time for assembly and calibration of such overcurrent tripping adjustment mechanisms is also high.
The existing overcurrent tripping adjustment mechanisms enable a single circuit breaker to be used in various applications. However, due to the above mentioned challenges such as large space requirement and high processing time, there is a need of an improved overcurrent tripping adjustment mechanism. Such an improved overcurrent tripping adjustment mechanism should be aimed at overcoming the aforementioned challenges.
SUMMARY
The Mechanism for magnetic tripping adjustability consists of two guide pillars holding a magnetic adjusting bar which are fixed in the base of the circuit breaker. And the cover consists of the rotary cover, rotary knob and the slider. The mechanism is engineered in a way keeping in mind the simplified and compact construction with lesser number of parts resulting in reduced assembly and calibration processing time and more accuracy. During the normal setting, the push pillars of the slider are in contact with the lower end of the slope profile of the magnetic adjusting bar and it rests at the locks of the guide pillars. When the knob is rotated in the anti-clockwise direction, the pinion of the rotary knob rotates which is linked with the rack of the slider giving it a linear motion towards left. Now, as the slider moves, the push pillars slide over the slope profile of the magnetic adjusting bar giving it a vertically downward movement. This compresses the springs attached to the moving armature increasing (or varying) the spring forces. So more (or variable) current is needed to develop the magnetic force strong enough to move the moving armature overcoming the increased (or varied) spring force and hence getting higher (or variable) magnetic tripping current levels. Also, the individual poles can be easily calibrated and adjusted using the adjuster screws incorporated within the magnetic adjusting bar. By rotating the adjuster screws, through the steps provided over it, the spring forces of the individual poles can be varied.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The foregoing and further objects, features and advantages of the present subject matter will become apparent from the following description with reference to the accompanying drawings, wherein like numerals are used to represent like elements.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter, and are therefore, not to be considered for limiting of its scope, for the subject matter may admit to other equally effective embodiments.
Figure 1 illustrates a perspective view of an overcurrent tripping adjuster mechanism in accordance with one of the embodiments of the present subject matter.
Figures 2 illustrates an exploded view of few components of the overcurrent tripping adjuster mechanism of Figure 1 depicting a portion of the unique multi-directional linkages in accordance with the present subject matter.
Figure 3 depicts another perspective view of the overcurrent tripping adjustment mechanism in accordance with one of the embodiments of the present subject matter.
DETAILED DESCRIPTION
Magnetic Adjustability can be obtained by varying the forces of the magnetic springs attached to the moving armature. As the current flows through the heater element, a magnetic flux is generated due to which the fixed armature acts as a magnet. This fixed armature, then attracts the moving armature towards itself so as to hit the trip bar resulting in the tripping of the circuit breaker. For the moving armature to move, it needs to overcome the magnetic spring forces. As we vary the spring compression (or spring’s length), the energy stored in it and hence the spring forces gets changed. Like, more (or lesser) be the springs’ compression, more (or lesser) will be the spring force and hence more (or lesser) will be current required to generate more (or lesser) magnetic force so as to attract the moving armature. This is how, by varying the spring forces (or spring compression), the variable magnetic tripping current levels can be obtained.
The Mechanism for overload tripping adjustability as shown in Fig.1, consists of two guide pillars (4), a magnetic adjusting bar (9), rotary knob (16), slider (8) and the rotary knob cover (17). The mechanism is engineered in a way keeping in mind the simplified and compact construction with lesser number of parts resulting in more accuracy. The base of the guide pillars (4) are made fixed in the base of the housing of the circuit breaker. The magnetic adjusting bar (9) being guided over their (4) pillar part and the magnetic plates (10), obtains a vertical movement. The locks (7) present at the top of the guide pillars (4), holds the magnetic adjusting bar (9) and prevent it from moving out. This magnetic adjusting bar (9) is incorporated with the adjuster screws (1) which hold the magnetic springs (11). The step (20) provided over the adjusting screw (1), compress or release the magnetic springs (11) as shown in Fig.3. With reference to the Fig.2, the rotary knob cover (17) holds and position the rotary knob (16) in a fixed place. When the rotary knob (16) is rotated, its pinion part (13) rotates, which is linked with the rack part (15) of the slider resulting in the linear (horizontal) motion of the slider (18) as shown in Fig.2. The push pillars (14) of the slider (18), slides over the slope profile (19) of the magnetic adjusting bar (9) and hence giving it a vertical movement guided perfectly by the pillar part of the guide pillars (4) and the magnetic plates (10). The magnetic springs (11) are held by the adjuster screws (1). The step (20) of the adjuster screws (1), compress or release the magnetic springs (11) as the magnetic adjusting bar (9) moves vertically up and down; hence varying the force which the moving armature (12) needs to overcome resulting in the varied magnetic overload tripping current.
During the minimum setting, the push pillars (14) of the slider (18) are in contact with the lower end (8) of the slope profile of the magnetic adjusting bar (9) and it rests at the locks (7) of the guide pillars (4). When the knob (6) is rotated in the anti-clockwise direction, the pinion part (13) of the rotary knob (16) rotates which is linked with the rack (15) of the slider giving it a linear motion towards left. Now, as the slider (18) moves, the push pillars (14) slide over the slope profile (19) of the magnetic adjusting bar (9) giving it a vertically downward movement as shown in Fig.1. This compress the magnetic springs (11) attached to the moving armatures (12) increasing the springs’ force. So more current is needed to develop the magnetic force strong enough to move the moving armature (12) overcoming the increased spring force and hence getting higher magnetic tripping current levels. Similarly, now when the knob (6) is rotated clockwise, the rotary knob (16) rotates and the slider (18) moves towards right. This makes the magnetic adjusting bar (9) to move vertically up; the push pillars (14) sliding from the upper end (21) to the lower end (8) of the slope profile of the magnetic adjusting bar (9). This results in the releasing of the magnetic springs (11) and hence lowering the magnetic overcurrent tripping current level. Also, the individual poles can be easily calibrated and adjusted using the adjuster screws (1) incorporated within the magnetic adjusting bar (9). By rotating the adjuster screws (1), through the step (20) provided over it, the magnetic springs’ (11) compression (or forces) of the individual poles are varied.

CLAIMS:
WE CLAIM:
1. An overcurrent tripping adjuster mechanism having multidirectional linkages comprising a slider mechanism configured to impart vertical motion to a magnetic adjusting bar (9) of the magnetic adjusting assembly. The magnetic adjusting assembly comprises plurality of guide pillars (4), magnetic springs (11), adjuster screws (1) along with the magnetic adjusting bar (9) with plurality of slope profile (19) over it. It is such that the plurality of push pillars (14) of the slider (18) of the slider mechanism are in contact with the plurality of slope profile (19) of the magnetic adjusting bar (9), so that as the slider (18) moves, it gives a vertical motion to the magnetic adjusting bar (9) which is guided over the guide pillars (4) and rests at the locks of the guide pillars (7). This through the adjuster screws (1), compress or release the respective magnetic spring (11) which varies the force required to attract the respective moving armatures (12) towards their respective fixed armatures (3) resulting in varied overcurrent tripping values.
2. The overcurrent tripping adjuster mechanism as claimed in claim 1, wherein the slider mechanism comprises a slider (18), rotary knob (16) and rotary knob cover (17).
3. The overcurrent tripping adjuster mechanism as claimed in claim 2, wherein the slider (18) comprises the plurality of push pillars (14) protruding downwards.
4. The overcurrent tripping adjuster mechanism as claimed in claim 2, wherein the pinion of the rotary knob (13) is linked with the rack (15) of the slider (18).
5. The overcurrent tripping adjustment mechanism as claimed in claim 2, wherein the rotary knob cover (17) encloses the knob (6) of the rotary knob (16) and holds it in fixed position.
6. The overcurrent tripping adjuster mechanism as claimed in claim 4, wherein the pinion of the rotary knob (13) is configured to impart linear motion to the slider (18) upon rotation of the knob (6).
7. The overcurrent tripping adjuster mechanism as claimed in claim 4, wherein the knob (6) is configured to be rotated to impart rotary motion to the pinion (13) of the rotary knob (16).
8. The overcurrent tripping adjuster mechanism as claimed in claim 1, wherein the magnetic adjusting bar (9) is guided over the guide pillars (4).
9. The overcurrent tripping adjuster mechanism as claimed in claim 1, wherein the magnetic adjusting bar (9) comprises a plurality of slope profiles (19) structurally formed over the magnetic adjusting bar (9) such that each of the plurality of push pillars (14) is configured to slide over the respective slope profiles (19) to provide vertical motion to the magnetic adjusting bar (9).
10. The overcurrent tripping adjuster mechanism as claimed in claim 1, wherein each of the plurality of slope profiles (19) comprises an upper end (21) and a lower end (8) of slope profile.
11. The overcurrent tripping adjuster mechanism as claimed in claim 1, wherein the plurality of magnetic springs (11) is attached with the magnetic adjusting bar (9) using the plurality of adjusting screws (1).
12. The overcurrent tripping adjuster mechanism as claimed in claim 8, wherein the plurality of guide pillars (4) comprises a lock (7) at a top end of the plurality guide pillars (4), configured to secure the magnetic adjusting bar (9).
13. The overcurrent tripping adjuster mechanism as claimed in claim 11, wherein the plurality of magnetic springs (11) is compressed/released by step 20, functionally disposed over each of the plurality of adjuster screw (1) during vertical motion of the magnetic adjusting bar (9).
14. The overcurrent tripping adjuster mechanism claimed in any of the preceding claims, wherein force required to be overcome by the moving armature (12) varies when each of the plurality of push pillars (14) slides between the lower end (8) and the upper end (21) of the plurality of slope profiles (19).
15. The overcurrent tripping adjuster mechanism as claimed in claim 11, wherein each of the plurality of magnetic springs (11) is individually and independently compressed/released by rotating the adjuster screw (1) using the groove over it for the calibration of each of the plurality of the poles of the circuit breakers.