Circuit breaker with inspection window

Abstract

The object of the invention is a high speed circuit breaker, for industrial or railways applications for interrupting a high DC current with high efficiency and extremely fast intervention times, having: a housing with mechanical and electrical components located within said housing, for opening or closing an electrical circuit, including arcing contacts, an opening in the side or on both sides of the housing of the circuit breaker, and further comprises a cover disposed on the side of the housing, wherein said cover is movable with respect to the opening between an open position and a closed position.

Description

[0001] The present invention relates to circuit breakers, especially to high speed circuit breakers for industrial or railways applications for interrupting a high D.C. current with high efficiency and extremely fast intervention times.

[0002] With time and while being used - all circuit breakers experience some kind of wear and accumulate dirt, often due to electric arc appearing during opening action of the breakers, even if for brief moments.

[0003] Ensuring the breakers are always ready to act and are not in need on replacement or more complicated maintenance activities is an important task, that requires periodic inspections. In some variants - in order to carry out the inspection parts of the housing of the circuit breaker need to be disassembled, and after the inspection - put back together. These actions take unnecessarily long to perform and also - leave some of the parts of the circuit breaker open, which can result in unwanted contaminants getting inside the structure of the circuit breaker.

[0004] On the other hand, from EP3389067B1 there is known a high speed circuit breaker for industrial and railways applications, that is provided with a cut-out in the side of the housing, which helps in performing inspections. However, just providing an opening is insufFicient in providing a reliable and safe way of performing inspections, as it doesn't help in protecting the outside of the breaker from possible sparks etc. that may come from the inside of the breaker. Also - such structure doesn't allow for guiding the gases from the area of electric arc towards a dedicated direction.

[0005] Also, from JP6180329B2, there is known a circuit breaker suitable for arc-extinguishing, by having a space constructed within the body of the breaker, and a shielding plate that covers an opening in the side of the breaker.

[0006] Therefore, the purpose of the present invention is to provide a circuit breaker that would have a structure allowing for carrying out visual inspection easily and conveniently, with the same accessibility throughout the time of use of the circuit breaker. Furthermore, another purpose of the present invention is to provide a circuit breaker with a structure, that would help in preventing the arc gas from flowing back to the contact and in directing the gas flow to the arc chamber.

[0007] The object of the invention is a high speed circuit breaker, for industrial or railways applications for interrupting a high DC current with high efficiency and extremely fast intervention times, having: a housing with mechanical and electrical components located within said housing, for opening or closing an electrical circuit, including arcing contacts, an opening in the side or on both sides of the housing of the circuit breaker, a cover disposed on the side of the housing, wherein said cover is movable with respect to the opening between an open position and a closed position.

[0008] Preferably, the cover is made from a non-flammable, self-extinguishing material.

[0009] Preferably, the cover is made of plastics material based on polyester resin with the addition of glass fibers.

[0010] Preferably, the cover is made of sheets of fiberglass laminated with polyester resin.

[0011] Preferably, in the closed position the cover fully covers the opening.

[0012] Preferably, in the closed position the cover partially covers the opening.

[0013] Preferably, the cover is provided with at least one socket, suitable for changing the position of the cover with respect to the housing.

[0014] Preferably, the cover is movable with respect to the housing by means of rotational movement.

[0015] Preferably, the cover is movable with respect to the housing by means of linear movement.

[0016] Preferably, the housing is provided with a tool opening configured for providing access to the socket for a tool for displacement of the cover between the open and closed positions.

[0017] Preferably, the cover is an assembly of parts, comprising: a movable part, a stationary part, connecting elements.

[0018] Preferably, the connecting elements comprise a screw and a nut.

[0019] Preferably, the socket is a part of the screw.

[0020] Thanks to the present invention, there are provided circuit breakers that are easier, more convenient and safer for inspection, as only a couple of elements need to be interacted with to perform inspection, and the internals of the circuit breaker remain mostly covered by the housing.Brief description of drawings

[0021] The present invention will be now briefly described with reference to the attached drawing, in which: Fig. 1 is a schematic view from the inside of the housing of the circuit breaker, with visible inspection window and a movable cover, Fig. 2 is an exemplary view from the outside of the circuit breaker, with visible inspection window and a part of the cover in the closed position, Fig. 3 is a perspective view of the breaker from Fig. 2 with parts of the housing removed and the window cover visible in full, Fig. 4 is an exemplary view from the outside of the circuit breaker, with visible inspection window and a part of the cover in the open position, Fig. 5 is a perspective view of the breaker from Fig. 4 with parts of the housing removed and the window cover visible in full, Figs. 6 and 7 present an exploded view of the parts directly connected to the cover, and Fig. 8 presents a cover combined with a stationary part and with a visible nut.

[0022] Circuit breaker, as shown in Figs. 2-5, has many components, that serve the general purpose of allowing it to open or close an electrical circuit, depending on the situation. It is provided with mechanical components - e.g. parts of the lever mechanism for actuating parts of the circuit breaker, and electrical components - e.g. electric contacts that include arcing contacts, that can experience electric arc during opening action of the circuit breaker.

[0023] As it is also visible on Figs. 1, 2 and 4 - the circuit breaker is provided with a housing 1, that encloses the internal components of the circuit breaker. Said housing 1 serves the purpose of protecting the internal components of the circuit breaker from the outside factors (like dirt, damages etc.) but also helps in protecting the outside of the circuit breaker from electric arc, possible sparks etc., that may appear inside the breaker.

[0024] As seen in Fig. 1, 2 and 4 - the housing 1 is provided with an opening 2, which is located on the side (or on both sides of the housing 1) of the circuit breaker and close to the area, where the movable electric contact of the circuit breaker is located (the electric contact is visible in the opening).

[0025] Due to the fact, that the described circuit breaker is of the industrial type / scale - the size of this opening 2 in the housing 1 has to be sufficient for performing inspection of the internal components of the circuit breaker. In a preferred embodiment, this opening 2 is at least 40 mm wide and 40 mm tall, and up to 120 mm wide and 120 mm tall, and preferably - the opening 2 in the housing 1 is 80 mm wide and 80 mm tall. Such sizes of the opening 2 allow for a convenient inspection of the internals of the circuit breaker, while also won't compromise the overall strength of the housing 1.

[0026] It should be noted, that the abovementioned size of the opening 2 in the housing 1 is not directed to only one geometrical shape. In different embodiments of the invention - the opening 2 could be rectangular, square, rectangular / square with rounded or cut corners, but also trapezoid or round or oval, etc. As long as the shape of the opening 2 allows for a convenient inspection of the state of internal components of the circuit breaker (especially state of arcing contacts) - it can be considered as preferable for the present invention.

[0027] As seen in Fig. 1, 3 and 5 - the circuit breaker is also provided with a cover 3, which is mounted movably on the side of the side of housing 1, close to the opening 2. This cover 3 is also partly visible on Fig. 2.

[0028] The cover 3 can be movable with respect to the housing 1 rotationally, linearly or otherwise, preferably rotationally.

[0029] The cover 3 can be mounted on the inside or on the outside of the housing 1, preferably it is mounted on the inside.

[0030] The cover 3 is made from an assembly of parts, that comprise a movable part 5a, a stationary part 5b and connecting elements, that include a socket 7.

[0031] The movable part 5a of the cover 3 in a most basic variant has a shape which is similar to a quarter of a circle - compare with Fig. 1, 6, 7 and 8.

[0032] In general - the movable part 5a of the cover 3 may have also other preferable shapes, not only that similar to a quarter of a circle. It could be a half-circle, a % of a circle or rectangular or trapezoid in shape (these shapes - not shown on Figures). What is important in designing a proper cover 3 is ensuring that is can cover the insides of the circuit breaker in sufficient manner, and also - can be conveniently displaced for performing inspection (and thus - has to have a shape suitable for it to be temporarily rotated or lifted away, without coming into conflict with other parts of the circuit breaker).

[0033] However, a more preferable shape is a little bit more complicated - one corner of that ~ ¼ of a circle shape is shaped from two lines that meet at an angle, preferably a right angle, while the other corner is formed from an extension of one of radii forming that ¼ of a circle (compare with Fig. 3 and 5). Such a shape ensures a very good covering of the insides of the circuit breaker, while also - is stable when rotated away and doesn't conflict with other parts of the circuit breaker.

[0034] The movable part 5a is arranged such, that it can be actuated between closed position, where it covers the area of arcing contacts of the circuit breaker, and open position, where it is moved away to allow visual inspection of the state of arcing contacts (compare Figs. 2 and 3 with 4 and 5).

[0035] The stationary part 5b has a generally trapezoid shape with two legs protruding from it, covering part of the opening 2 in the housing 1 of the circuit breaker but also preparing a viewing window for inspection.

[0036] The connecting elements preferably comprise a screw 6 and a nut 8, wherein the screw 6 is provided with a socket 7.

[0037] The screw 6 is arranged to go through the stationary part 5b and also through the cover 3, and serve as an axis of rotation for the movable part 5a of the cover 3.

[0038] The nut 8 locks the movable part 5a on the screw 6. The screw 6 has a head, which is provided with a socket 7. This socket 7 is accessible through and opening 4 in the housing 1 of the circuit breaker.

[0039] Said actuation can be performed in a variety of ways - the movable part 5a can be provided with a little "knob" (not shown) that can be used to grab it and manually rotate or lift the movable part 5a of the cover 3. In a further embodiment, the stationary part 5b of the cover 3 may be provided with a slot (not shown) configured to cooperate with said knob and "catch / hold" it, with the movable part 5a locked in an open position. In other embodiments, the cover may be configured such with respect to a possible axis of rotation, that after being rotated from closed into an open position - it stays in this open position due to gravity. While there are many possible configurations, it should be understood that safety is very important factor when designing the cover 3, and it would be preferable to operate (open and close) the movable part 5a without the need to actually touch it by hand of the person performing the inspection.

[0040] Having the abovementioned in mind - the opening and closing of the cover 3 is preferably performed using a dedicated tool, insertable through a dedicated opening / hole 4 in the housing 1 of the circuit breaker (see Figs. 2 and 4). Preferably, the cover 3 is provided with a socket shaped to fit a TX30 type screwdriver, which helps in lowering the risk of unwarranted lifting of the cover, as such screwdrivers aren't of the most common type. In a different embodiment -the socket could be shaped to cooperate with another tool, like a different screwdriver or even a dedicated and non-typical tool.

[0041] The cover 3, in order to withstand the dangers of being located in close proximity of arcing contacts, where electric arc can appear, should be made of a non-flammable and self-extinguishing material. Preferably, the cover 3 is made of plastics material based on polyester resin with the addition of glass fibers, e.g. from sheets of fiberglass laminated with polyester resin.

[0042] List of numeral references: 1 - housing 2 - opening 3 - cover 4 - tool opening 5a - movable part of cover 3 5b - stationary part of cover 3 6 - screw 7 - socket 8-nut

Claims

1. A high speed circuit breaker, for industrial or railways applications for interrupting a high DC current with high efficiency and extremely fast intervention times, having: a housing (1) with mechanical and electrical components located within said housing, for opening or closing an electrical circuit, including arcing contacts, an opening (2) in the side or on both sides of the housing (1) of the circuit breaker, characterized in that, it further comprises a cover (3) disposed on the side of the housing (1), wherein said cover (3) is movable with respect to the opening (2) between an open position and a closed position.

2. A high speed circuit breaker according to claim 1, wherein the cover (3) is made from a non-flammable, self-extinguishing material.

3. A high speed circuit breaker according to claim 2, wherein the cover (3) is made of plastics material based on polyester resin with the addition of glass fibers.

4. A high speed circuit breaker according to claim 2, wherein the cover (3) is made of sheets of fiberglass laminated with polyester resin.

5. A high speed circuit breaker according to claim 1, 2, 3 or 4, wherein in the closed position the cover (3) fully covers the opening (2).

6. A high speed circuit breaker according to claim 1, 2, 3 or 4, wherein in the closed position the cover (3) partially covers the opening (2).

7. A high speed circuit breaker according to claim 1, 2, 3, 4, 5 or 6, wherein the cover (3) is provided with at least one socket (7), suitable for changing the position of the cover (3) with respect to the housing (1).

8. A high speed circuit breaker according to claim 7, wherein the cover (3) is movable with respect to the housing (1) by means of rotational movement.

9. A high speed circuit breaker according to claim 7, wherein the cover (3) is movable with respect to the housing (1) by means of linear movement.

10. A high speed circuit breaker according to claim 7, 8 or 9, wherein the housing (1) is provided with a tool opening (4) configured for providing access to the socket (7) for a tool for displacement of the cover (3) between the open and closed positions.

11. A high speed circuit breaker according to any one of the claims from 1 to 9, wherein the cover (3) is an assembly of parts, comprising: - a movable part (5a) - a stationary part (5b) - connecting elements.

12. A high speed circuit breaker according to claim 11, wherein the connecting elements comprise a screw (6) and a nut (8).

13. A high speed circuit breaker according to claim 7 and 12, wherein the socket (7) is a part of the screw (6).

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