Tripping mechanism

Abstract

The invention relates to a trip mechanism suitable for an overcurrent trip unit designed for high-current busbars, comprising a magnetic core (1) having a first yoke (2a), a second yoke (2b) and a third yoke (2c), the third yoke (2c) comprising a yoke through-hole, an armature (3) comprising an armature through-hole, a guide rod (4) with a fixing device, a spring (6) and a device for tensioning the spring (6), a tripping lever (9), means for transmitting the movement of an armature (3), the armature (3) being movably placed between a first yoke (2a) and a second yoke (2b), in which a guide rod (4) extends through the magnetic core (1), i.e. Through the second yoke (2b), between the arms of the first yoke (2a), and through a yoke through-hole of a third yoke (2c), and the armature (3), i.e. Through an armature through-hole, and meanwhile, the position of the guide rod (4) is fixed by a fixing device relative to the magnetic core (1).

Description

Technical Field

[0001] The invention relates to a tripping mechanism which is suitable for an overcurrent tripping unit designed for a high-current busbar. Background Art

[0002] In known trip unit designs, the trip force is transferred from the armature, located above the circuit breaker busbars, to the space below the busbars via a rod (the so-called "trip bar") attached to the armature assembly and positioned to the side of the trip unit. The trip bar axis is parallel to and offset from the guide bar axis. The trip bar actuates the trip lever, thereby activating the trip system to open the circuit breaker.

[0003] The tripping force generated by the armature assembly acts along the guide rod axis. The tripping reaction force from the trip rod acts along the trip rod axis. When both axes move a certain distance, these two forces generate momentum. This momentum acts on the armature, which then acts on the guide rod, creating additional friction between the armature and the guide rod. Furthermore, this momentum creates additional tension / strain in the system, which requires additional armature travel to compensate. This additional friction and travel negatively impact the circuit breaker's high-speed breaking capability and low-current tripping capability. Summary of the Invention

[0004] The present invention relates to a trip mechanism suitable for use in an overcurrent trip unit. The trip mechanism includes a magnetic core having a first magnetic yoke, a second magnetic yoke, and a third magnetic yoke, wherein the third magnetic yoke includes a yoke through-hole; an armature including an armature through-hole; a guide rod having a fixing device; a spring and a device for tensioning the spring; a trip lever; and a device for transmitting the movement of the armature. The armature is movably positioned between the first and second magnetic yokes. The guide rod extends through the magnetic core—i.e., through the arms of the first magnetic yoke, between (the arms of) the second magnetic yoke, and through the yoke through-hole of the third magnetic yoke—and the armature, i.e., through the armature through-hole. The position of the guide rod relative to the magnetic core is fixed by the fixing device. The guide rod is positioned inside the spring, which is positioned between the armature and the tensioning device. The spring extends through the yoke through-hole of the third magnetic yoke. The spring is configured to urge the armature toward the first magnetic yoke. The device for transmitting the movement of the armature is positioned inside the yoke through-hole of the third magnetic yoke and outside the spring and is configured to transmit the movement of the armature between the first and second magnetic yokes to the trip lever.

[0005] Preferably, the means for transmitting the movement of the armature is in the form of a tube.

[0006] Preferably, the tube is perforated or made of a mesh member.

[0007] Preferably, the tube is connected to the armature.

[0008] Preferably, the tube is connected to a guide member connected to the armature.

[0009] Preferably, the connection is achieved with a tight fit.

[0010] Preferably, the connection is achieved by means of threads.

[0011] Preferably, the means for transmitting the movement of the armature comprises at least one extension in contact with the trip lever.

[0012] Preferably, at least one extension is a retaining ring.

[0013] Preferably, at least one extension is fixedly connected to the device for transmitting the movement of the armature.

[0014] Preferably, the trip lever comprises a fork which comes into contact with the means for transmitting the movement of the armature.

[0015] Preferably, the trip lever comprises a straight section and a curved section.

[0016] Preferably, one of the fixing means is an adjusting tube, wherein the adjusting tube is configured to act as a means for tensioning the spring, the adjusting tube being placed inside the means for positioning the adjusting tube connected to the magnetic core.

[0017] Preferably, the adjustment screw is mechanically coupled to the adjustment tube, preferably by means of a gear.

[0018] Preferably, one of the fixing means is a plate fixed to the magnetic core, the guide rod being fixed to said plate by means of screws or threaded structures.

[0019] The object of the present invention is to overcome the problems of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Preferred embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0021] Figure 1 An overcurrent trip unit having a trip mechanism according to the present invention is shown,

[0022] Figure 2 shows a cross-sectional view of the overcurrent trip unit shown in FIG1 ,

[0023] Figure 3 Shown Figure 1 Detailed cross-sectional view of the tripping mechanism of the overcurrent trip unit,

[0024] Figure 4 Shown Figure 1 A detailed cross-sectional view of the tripping mechanism of the overcurrent tripping unit, wherein the cross-sectional view is perpendicular to Figure 3 Cross-sectional view shown. DETAILED DESCRIPTION

[0025] According to the present invention, a trip mechanism suitable for use in an overcurrent trip unit is disclosed. The trip mechanism includes: a magnetic core 1 having a first yoke 2a, a second yoke 2b, and a third yoke 2c, wherein the third yoke 2c includes a yoke through-hole; an armature 3 including an armature through-hole; a guide rod 4 having a fixing device, a spring 6, and a means for tensioning the spring 6; a trip lever 9; and a means for transmitting movement of the armature 3, wherein the armature 3 is movably positioned between the first and second yokes 2a, 2b. The guide rod 4 extends through the magnetic core 1—that is, through the second yoke 2b, between the arms of the first yoke 2a, and through the yoke through-hole of the third yoke 2c—and the armature 3, that is, through the armature through-hole. The position of the guide rod 4 relative to the magnetic core 1 is fixed by the fixing device. The guide rod 4 is positioned within the spring 6, which is positioned between the armature 3 and the tensioning device. The spring 6 extends through the yoke through-hole of the third yoke 2c. The spring 6 is configured to bias the armature 3 toward the first yoke 2a. The means for transmitting the movement of the armature 3 is placed inside the yoke through-hole of the third yoke 2c and outside the spring 6, and is configured to transmit the movement of the armature 3 between the first yoke 2a and the second yoke 2b to the trip lever 9. In this arrangement, force is generated and transmitted by the means for transmitting movement along the axis of the guide rod 4 - in this configuration, there is no momentum generation or bending / flexing, thus overcoming the shortcomings of the trip mechanisms of the prior art.

[0026] It will be appreciated that, due to the tension, the spring 6 acts so that during normal operation the armature 3 is in a first position, i.e., close to the first yoke 2a, and when the current is greater than a threshold value, the armature 3 moves to a second position, i.e., close to the second yoke 2b, and then, when the current stops flowing, the spring 6 returns the armature 3 to the first position. In the embodiment shown, the spring 6 is a compression spring, however, any other type of spring that will provide the same result may be used.

[0027] In one embodiment, the means for transmitting the movement of the armature 3 is in the form of a tubular member 5, however, those skilled in the art will appreciate that any other rigid shape may be used. For example, the tubular member 5 may be perforated or made of a mesh member. Generally, the means for transmitting the movement of the armature 3 need not be connected to the armature 3, however, such an alternative is possible, for example, the tubular member 5 may be connected to the armature 3. Alternatively, the means for transmitting the movement of the armature 3 may be connected to the guide member 12 connected to the armature 3, for example, the tubular member 5 may be connected to the guide member 12 connected to the armature 3. This connection may be achieved, for example, by a tight fit or by means of a threaded structure, however, those skilled in the art will appreciate other possibilities.

[0028] In another embodiment, the means for transmitting the movement of the armature 3 comprises at least one extension that contacts the trip lever 9. The at least one extension provides an easier way to transmit the movement from the means for transmitting the movement of the armature 3 to the trip lever 9. For example, the at least one extension is a retaining ring / snapping ring 8. The at least one extension can form a fixed connection with the means for transmitting the movement of the armature 3.

[0029] In another example, the tripping lever 9 comprises a fork in contact with the means for transmitting the movement of the armature 3 .

[0030] In another embodiment, the trip lever 9 includes a straight section 9a and a curved section 9b.

[0031] In yet another embodiment, one of the fixing means is an adjustment tube 10. The adjustment tube 10 is configured to serve as a device for tensioning the spring 6, wherein the adjustment tube 10 is placed within a device 11 for positioning the adjustment tube 10, which is connected to the magnetic core 1. Another example of a fixing means is a plate 13 fixed to the magnetic core 1, wherein the guide rod 4 is fixed to the plate 13 by screws or a threaded structure.

[0032] In yet another embodiment, the adjusting screw 14 is preferably mechanically coupled to the adjusting tube 10 via gears. The adjusting screw 14 allows for easier adjustment, particularly when the gear ratio provided by the gears allows the adjusting screw 14 to rotate further than the adjusting tube 10 - in which case a more precise adjustment can be achieved and a stronger / more powerful spring 6 can be used.

[0033] Reference Signs List

[0034] 1 magnetic core

[0035] 2a First yoke

[0036] 2b Second yoke

[0037] 2c Third yoke

[0038] 3 armature

[0039] 4 guide rods

[0040] 5 pipe fittings

[0041] 6 springs

[0042] 7 busbars

[0043] 8 sets of rings

[0044] 9 Trip lever

[0045] 9a straight section

[0046] Turn 9b

[0047] 10 Regulating tube

[0048] 11 Device for positioning the regulating tube

[0049] 12 guides

[0050] 13 boards

[0051] 14 Adjusting screw

Claims

1. A tripping mechanism, applicable to an overcurrent tripping unit, comprising: A magnetic core (1) having a first magnetic yoke (2a), a second magnetic yoke (2b) and a third magnetic yoke (2c), wherein the third magnetic yoke (2c) includes a yoke through-hole, An armature (3) including an armature through hole, A guide rod (4) with a fixing device, a spring (6) and a device for tensioning the spring (6), Trip lever (9), means for transmitting the movement of the armature (3), wherein the armature (3) is movably placed between the first magnetic yoke (2a) and the second magnetic yoke (2b), The guide rod (4) extends through the magnetic core (1), that is, through the second magnetic yoke (2b), between the arms of the first magnetic yoke (2a), and the yoke through-hole of the third magnetic yoke (2c), and the armature (3), that is, through the armature through-hole. At the same time, the position of the guide rod (4) is fixed relative to the magnetic core (1) by the fixing device. The guide rod (4) is placed inside the spring (6), the spring (6) is placed between the armature (3) and the device for tensioning the spring (6), the spring (6) extends through the yoke through-hole of the third magnetic yoke (2c), and the spring (6) is configured to apply force to the armature (3) toward the first magnetic yoke (2a). The device for transmitting the movement of the armature (3) is placed inside the yoke through hole of the third yoke (2c) and outside the spring (6), and is configured to transmit the movement of the armature (3) between the first yoke (2a) and the second yoke (2b) to the tripping lever (9).

2. The tripping mechanism according to claim 1, wherein: The means for transmitting the movement of the armature (3) is in the form of a tube (5).

3. The tripping mechanism according to claim 2, wherein: The pipe (5) is perforated or made of a mesh member.

4. The tripping mechanism according to claim 2 or 3, wherein: The pipe fitting (5) is connected to the armature (3).

5. The tripping mechanism according to claim 2 or 3, wherein: The pipe member (5) is connected to a guide member (12), and the guide member is connected to the armature (3).

6. The tripping mechanism according to claim 4 or 5, wherein: The connection is achieved in a tight fit.

7. The tripping mechanism according to claim 4 or 5, wherein: The connection is achieved by means of threads.

8. The tripping mechanism according to any one of claims 1 to 7, wherein: The means for transmitting the movement of the armature (3) comprise at least one extension in contact with the trip lever (9).

9. The tripping mechanism according to claim 8, wherein: The at least one extension is a retaining ring (8).

10. The tripping mechanism according to claim 8 or 9, wherein: The at least one extension is fixedly connected to a device for transmitting the movement of the armature (3).

11. A trip mechanism according to any one of the preceding claims, wherein: The trip lever (9) comprises a fork which contacts the means for transmitting the movement of the armature (3).

12. The tripping mechanism according to any one of claims 1 to 11, wherein: The trip lever (9) comprises a straight section (9a) and a curved section (9b).

13. The tripping mechanism according to any one of claims 1 to 12, wherein: One of the fixing means is an adjusting tube (10) configured to act as the means for tensioning the spring (6), the adjusting tube (10) being placed inside a device (11) for positioning the adjusting tube (10) connected to the magnetic core (1).

14. The tripping mechanism according to claim 13, wherein: The adjusting screw (14) is preferably mechanically coupled to the adjusting tube (10) via a gear.

15. The tripping mechanism according to any one of claims 1 to 14, wherein: One of the fixing means is a plate (13) fixed to the magnetic core (1), and the guide rod (4) is fixed to the plate (13) by means of a screw or thread structure.

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