This patent application is a U.S. National Stage application of International Patent Application Number PCT/BR2016/050073 filed Apr. 1, 2016, which is hereby incorporated by reference in its entirety.
The present invention belongs to the technological field of operating mechanisms of electrical protection switch operation by rotary component, and more particularly to a switching operation mechanism for a circuit breaker and a molded case, used to ease manual operation of the operating handle of a circuit breaker, or alternatively in applications to control panels, wherein the circuit breaker is inside thereof, and it is necessary to provide an extension, which is capable of providing alternate operation at the front portion of said panel.
In general terms, the switching operation mechanism to a circuit breaker in molded case, as disclosed herein, comprises a external rotary handle, a two-part structural housing, comprising an operation member cooperating with said external rotary handle, able to move in an analogous trajectory to the trajectory of the molded case circuit breaker.
As well known to those skilled in the art, the circuit breakers currently known can have their operation based on thermal, magnetic, thermomagnetic or electronic principles, and can be used, above all, for the protection of electrical circuits subject to short circuits and/or electrical overloads generated by electric current peaks that exceed a nominal limit previously established, by the movement of electric contacts.
In this sense, it is verified that the circuit breakers function essentially analogously to the electrical switches, that is, they operate in order to change the electrical conduction state of an electric circuit between switched on and switched off. In addition to actuating automatically, the conventional circuit breakers also comprise an operating handle operated by a user. Such operating handles may further be coupled to switching operation mechanisms, which are used primarily in at least two situations: I) in circuit breakers for high current electrical circuits, wherein the force required to move the handle is usually relatively large for manual operations—especially in circuit breakers used in high current circuits, for example in the order of 1600 A; and II) in circuit breakers installed in panel housings which, for safety reasons, tend to be locked, which makes it difficult to directly access the circuit breaker, and wherein it is desirable that the operating handle of the switching operation mechanism is available on the external face thereof.
It is common to note in the prior art that most of these models and constructions of switching operation mechanisms to the circuit breakers are fundamentally based on the functional principle of mechanical cooperation between a pinion and a rack. Such functional principle is widely used in several fields of mechanics and widely known to those skilled in the art.
According to this operating principle, the pinion and the rack, physically coupled together, are usually disposed inside a protective enclosure, coupled to the circuit breaker and are associated with the circuit breaker operating handle. From this, a transmission of movements between these members occur, wherein the rotational movement of the external rotary handle of the switching operation mechanism, exerted manually by a user, triggers the rotational movement of the pinion and, consequently, the displacement of the linear trajectory of the rack, such displacement, which acts directly on the operating handle of the molded case circuit breaker, changing the operating position.
Based on of this context, it is possible to observe that such functional principle comprises some technically disadvantageous aspects.
A relevant technical aspect is that the rack, in its movement, moves in a linear trajectory, whereas the operating handle of the circuit breaker, due to its internal mechanism of action, moves in a rotating trajectory. In this sense, the interaction between these members causes a relative displacement between the rack of the switching operation mechanism and the handle for operating the circuit breaker, consequently, resulting in a high friction and a partial loss of the energy applied in the external rotary handle of said switching operation mechanism.
It should be noted that the cited movement of the handle for operating the molded case circuit breaker is internally rotating, such movement being due to its internal operation mechanism, which performs the opening and closing of its electrical circuit contacts, and observable in a lateral section plane. When the movement of an external rotating handle of the operation mechanism coupled to the molded case circuit breakers is reported, the said rotational movement is observed in the front operating plane.
Molded case circuit breakers are widely known in the prior art, comprising an operation handle that, mounted within the circuit breaker housing, protrudes out of the housing to provide manual operation of said circuit breaker.
The document US2006077023 discloses a circuit breaker in molded case comprising a switch on/off command mechanism and shot, comprising a movable rotary handle in the “A” or “B” directions for manually switching a circuit. Such condition is detailed in paragraph 40 of said document, in which it is further cited that the type of construction of the switching mechanism is well known, and for this reason further details have been omitted in the explanation. Another similar molded case circuit breaker is described in the document U.S. Pat. No. 6,084,191, especially in FIGS. 1 to 9. Such document also reports the existence of an operating handle (showing the circuit breaker in the side section plane) capable of visible movement in a rotational trajectory in their stages of operation. These types of circuit breaker in molded case, as in document US20060077023 or U.S. Pat. No. 6,084,191 is the type used together with the invention.
Switching operation mechanisms used to facilitate the switch on/off operation of molded case circuit breaker already encompassed by the prior art.
A constructive example is described in document EP1218914, whereby said switching operation mechanism is essentially comprised of two cooperating gears to each other, one large and one small that, combined, analogously operate a pinion and a rack. It is further provided an external rotary handle associated with the large gear, and in addition, it is noted that the rotational movement of the gears (imposed by the rotational movement of the external rotary handle triggers the linear trajectory displacement of the rack capable of moving the operating handle of the circuit breaker coupled thereto.
Other switching operation mechanisms containing similar actuating levers exist, as foreseen in the document GB 1161310, which describes an accessory mechanism containing rack and pinion, both used in order to facilitate the operation of the operating handle of the molded case circuit breaker or promote the transfer of the operating handle of a circuit breaker, located at the backside of a panel for the front of the operation.
Furthermore, the document GB 2279810 also discloses a coupling actuation mechanism in rectangular shape, comprising a locking system and a handle displaced from the center of the circuit breaker operating handle, a gear and an internal lever containing a gear hole. Such a mechanism has the disadvantage that due to the construction of said inner lever be displaced from the center of rotation of said rotary handle of the mechanism the force required to operation the rotary handle of the mechanism is greater than the force required to move the operating handle of the circuit breaker itself.
In the prior art documents it can be seen that the switching operation mechanisms for operating the handle of a circuit breaker fail to provide the contact between the internal mechanism and the circuit breaker handle for it does not follow its rotational movement.
Accordingly, it is verified that the present state of the art comprises a wide variety of designs and constructions of switching operation mechanisms for molded case circuit breakers, which have failed to solve imperfections in the movement transfer system between an operating handle of a molded case circuit breaker and a switching operation mechanism.
Therefore, it is an object of the invention to disclose a switching operation mechanism for molded case circuit breaker, the transmission medium of which is capable of developing a movement or displacement of a trajectory analogous to the reversible rotary trajectory of the operating handle of a circuit breaker, or similarly, whose transmission medium is capable of developing a movement or displacement with a rotating or arc-shaped trajectory.
It is also an object of the invention to provide a operation mechanism for circuit breaker free from disadvantageous technical aspects observed in the prior art constructions and, more particularly, exempted from technical aspects related to the inefficient transfer of movement and to the high wear of parts of the moving components.
Another object of the invention is to use a bevel gear system, which increases the lateral compaction of the switching operation mechanism to a circuit breaker.
Another object of the invention is that a switching operation mechanism for circuit breakers in molded case does not exceed their lateral dimensions.
Another object of the invention is that the housing construction comprises a laterally split body.
Another object of the invention is to construct a switching operation mechanism for a circuit breaker, which requires less mechanical effort by the user to operate on the handle of said circuit breaker.
Finally, another objective of the invention is that said preferred embodiment of the main structural components of the movement transmission of the switching operation mechanism to the circuit breaker can be integrally made in polymer or other molded material.
The aforementioned objectives are fully achieved by means of the switching operation mechanism for molded cased circuit breaker, of the type comprising at least one external operating rotating handle, capable of moving in a rotational trajectory.
According to the invention, the switching operation mechanism comprises at least one rotary handle, at least one operation member and at least one movement transmitting means, wherein said operation member of the switching operation mechanism is likely to cooperate with the operating handle of the molded case circuit breaker.
The invention stands out by the fact that the said operation member is likely to move in rotating trajectory toward equivalent to or analogous to the movement in rotational trajectory of the operating handle of the molded case circuit breaker, wherein the said movement in reversible rotational trajectory of the operation member, is able to change the position of the handle for operating the molded case circuit breaker.
The present invention, as well as the embodiments thereof will be described in detail based on the figures listed below, including:
Preliminarily, it is worth clarifying that the subject matter of the invention, the switching operation mechanism (2), is especially designed to a molded case circuit breaker (1), of the type comprising an operating handle (11), movable in rotational trajectory, as shown in
Having as base the cited
In this regard, and aiming to solve the technical problems previously mentioned, it is an object of the invention the operation member (22) being rotably moveable in rotational trajectory towards equivalent direction to the of the rotational trajectory movement of the operation handle (11) of the of the molded case circuit breaker (1). Evidently, the movement of the operation member (22), which is imposed by the movement of the external rotary handle (21) is responsible for changing the position of the handle (11) for operating the molded case circuit breaker (1).
According to a first preferred embodiment of the switching operation mechanism (2), as shown in
This means that the switching operation mechanism (2), according to the preferred embodiment of the invention, comprises a rail (3) whose rotational trajectory is equivalent to the rotational trajectory of the operating handle (11) of the molded case circuit breaker (1).
With this, an efficient transfer of movements is achieved, after all, practically the totality of the torque applied on the operation member (22) is also applied to the operating handle (11) of the molded case circuit breaker (1).
In addition, the switching operation mechanism (2) in accordance with the original concept of the present invention also enables misalignment between the laterally centralized position of the operating handle (11) of the molded case circuit breaker (1) in the plane “X” and the position laterally displaced of the external rotary handle (21) of the switching operation mechanism (2) in “Y” plane. Accordingly, the invention also overcomes the problems related to the preferred dimensions that an external rotary handle must have so that an average user is able to effectively change the position of the handle (11) of the molded case circuit breaker (1). This means that it is possible to keep an external rotary handle (21), of large dimensions in proportion to the assembled assembly, still “inside” the general perimeter of the molded case circuit breaker (1), achieving satisfactory results, even in situations in which said molded case circuit breaker (1) comprises miniaturized dimensions and wherein it may require the application of a large lever force on the external rotary handle (21) of the switching operation mechanism (2), for moving its operating handle (11).
Another object achieved with the present invention is that the position of the teeth (41) of the operation member (22) is further away from the center of rotation (54) relative to the end (11a) of the handle (11), increasing the distance between the center of rotation (54) and the line of action (56), responsible for the transmission of force applied by the gear (52) on the operation member (22), requiring less proportional operational mechanical power of the user operation on the external rotary handle (21) for an equal movement of the handle (11) for operating the molded case circuit breaker (1), due to the classical mechanics concept that the greater the distance, the greater the torque, the force being maintained constant.
It can be observed the position of the teeth (41) and a line of action (56), tangential to a primitive diameter (55), where a transmission force is applied by the gear (52) on the operation member (22), which is further away from the center of rotation (54) relative to the end (11a) of the handle (11).
Furthermore, according to preferential embodiments of the invention, particularly as illustrated in
Also according to a first and second preferred embodiments of the invention, the movement transmission means (23), comprises a first gear (51) coupled to the external rotary handle (21) and a second gear (52), cooperating with the operation member (22), wherein the first gear (51) and the second gear (52) are both perpendicularly coupled to each other. In particular, the first gear (51) comprises a conical gear type, provided with multiple teeth arranged on its face of larger area, and the second gear (52) comprises a pinion gear type provided with multiple teeth comprising preferably a conical portion and another flat portion.
It should also be noted that, as shown in
In a second preferred embodiment, where the circuit breaker (1) is assembled behind a protective or enclosed panel (not shown) as shown in
In addition, considering both the first preferred embodiment as the second preferred embodiment of the invention, it is verified that the main components that comprise the switching operation mechanism (2), the operation member (22) and the movement transmission means (23) are arranged within a housing (7), which comprises a body (72a) and a detachable lid (72b), the body (72a) comprising a passing hole (71), for the accommodation of the external rotary handle (21) or extension shaft (6).
In addition, and as specifically shown in
In this sense, considering all the above, it is important to highlight that the present disclosure has the sole purpose of describing the exemplary method of preferred embodiments of the switching operation mechanism for molded case circuit breaker according to the invention. Accordingly, as is well understood by those skilled in the art, several modifications, variations and constructive combinations of the members exerting the same function in substantially the same manner to achieve the same results are possible, which should be included within the scope of protection defined by the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/BR2016/050073 | 4/1/2016 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2017/165932 | 10/5/2017 | WO | A |
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Number | Date | Country |
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1218914 | Mar 2001 | EP |
1161310 | Aug 1969 | GB |
2279810 | Jan 1995 | GB |
Number | Date | Country | |
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20190115181 A1 | Apr 2019 | US |