Patent Description:
In the field of electrical equipment, a circuit breaker is typically connected to a main circuit so as to cut off the main circuit when a current in the circuit exceeds a threshold. The circuit breaker includes a moving contact and a stationary contact, which can be coupled to each other to form a complete circuit. If the current through the circuit breaker is too large, the moving contact would be driven to decouple from the stationary contact to cut off the circuit.

The firmness of the connection between the moving contact and the stationary contact should be appropriate. At one end, if a contact pressure provided between the moving contact and the stationary contact is too small, the connection is too loose, a slight shaking or vibration during the operation of the circuit breaker may then cause the moving contact to accidentally disengage from the stationary contact, which is undesirable. At the other end, if the contact pressure provided between the moving contact and the stationary contact is too large, a driving unit is unable to remain the moving contact in a correct and reliable location, which is also undesirable. Therefore, how to adjust the firmness of the connection between the moving contact and the stationary contact in a straightforward and convenient manner remains a challenge.

<CIT> discloses an adjusting mechanism of a circuit breaker according to the preamble of claim <NUM>.

In general, example embodiments of the present disclosure provide a solution for adjusting the firmness of the connection between the moving contact and the stationary contact conveniently and intuitively.

In a first aspect, there is provided an adjusting mechanism of a circuit breaker. The adjusting mechanism comprises an operating rod configured to operate a moving contact of the circuit breaker via a contact spring arranged between the operating rod and the moving contact; a transmitting rod pivotally coupled to the operating rod and configured to drive the operating rod to move towards or away from a stationary contact of the circuit breaker; an adjusting block pivotally coupled to the transmitting rod at a position different from the operating rod and comprising a thread hole; a bracket comprising a first supporting element and a second supporting element spaced from the first supporting element along a first direction, each of the first supporting element and the second supporting element comprising a through hole extending along the first direction; and an adjusting bolt extending through the through hole of the first supporting element, the thread hole of the adjusting block, and the through hole of the second supporting element sequentially along the first direction, the adjusting bolt comprising an external thread engaging with the thread hole, such that when the adjusting bolt is actuated to rotate about its axis, the adjusting block slides along the first direction between the first supporting element and the second supporting element.

According to embodiments of the present disclosure, a stroke of the contact spring can be adjusted in a convenient and precise manner. In this way, the firmness of the connection between the moving contact and the stationary contact can be adjusted conveniently and reliably.

In some example embodiments, the bracket further comprises: a third supporting element arranged between the first supporting element and the second supporting element and configured to support the adjusting block when the adjusting block slides between the first supporting element and the second supporting element. In this manner, the adjusting block can move robustly along the adjusting bolt upon the adjusting bolt being actuated to rotate.

In some example embodiments, the adjusting block further comprises: a block body provided with the thread hole; and two wings provided at both sides of the block body along a second direction perpendicular to the first direction and configured to be supported by the third supporting element. In this manner, a contact area between the adjusting block and the bracket can be increased to ensure a more reliable movement of the adjusting block.

In some example embodiments, each of the two wings has a height smaller than a height of the block body along a third direction perpendicular to the first direction and the second direction. In this way, the adjusting block can occupy a smaller space within the circuit breaker.

In some example embodiments, each of the two wings comprises a second thread hole extending along the third direction and configured to allow a fastening bolt to penetrate therethrough to mount the adjusting block onto the third supporting element of the bracket. In this way, after the adjusting block is driven to a desired position, it can be locked to the bracket to allow the operating rod to be driven by the transmitting rod.

In some example embodiments, each of the first supporting element, the second supporting element and the third supporting element comprises a plate. In this way, the bracket is easy to manufacture and of low cost.

In some example embodiments, a bolt head of the adjusting bolt abuts the first supporting element, and a free end of the adjusting bolt opposite to the bolt head abuts the second supporting element and is coupled to a locknut. In this way, the adjusting bolt can be adjusted in a reliable and cost-effective manner.

In some example embodiments, the bolt head is a hexagonal bolt head. In this way, the adjustment of the bolt head can be carried out in a more intuitive manner.

In some example embodiments, the first supporting element and the second supporting element are parallel to each other. In this way, the first supporting element and the second supporting element can be provided in a more compact manner.

In a second aspect, a circuit breaker is provided. The circuit breaker comprises a stationary contact; and a moving contact configured to be operated by an operating rod of an adjusting mechanism of the first aspect.

In some example embodiments, the circuit breaker further comprising: a first actuation element coupled to the moving contact; a second actuation element coupled to the operating rod of the adjusting mechanism; and a contact spring having one end coupled to the first actuation element and the other end coupled to the second actuation element. In this manner, the stroke of the contact spring can be adjusted simply by rotating the adjusting bolt.

In some example embodiments, the first actuation element comprises a protrusion at one end and an annular shoulder adjacent to the protrusion, and the second actuation element comprises a cylindrical chamber adjacent to an end portion, the cylindrical chamber comprising an opening to allow the protrusion, the shoulder and the contact spring to be contained within the chamber, the contact spring being provided between the shoulder of the first actuation element and an inner wall of the cylindrical chamber. In this manner, the contact spring can be securely provided within the cylindrical chamber to exert a contact pressure between the moving contact and the stationary contact.

Through the following detailed description with reference to the accompanying drawings, the above and other objectives, features and advantages of the example embodiments disclosed herein will become more comprehensible. In the drawings, several example embodiments disclosed herein will be illustrated in an exemplary and in a non-limiting manner, wherein:.

Principles of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and to help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to apply such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It should be understood that although the terms "first" and "second" etc. may be used herein to describe various elements, these elements should not be limited by these terms.

According to embodiments of the present disclosure, a maintenance worker or a robot is allowed to adjust the firmness of the connection between the moving contact and the stationary contact accurately outside the circuit breaker.

Example embodiments will be described in more detail hereinafter in accordance with <FIG>.

As illustrated in <FIG>, the circuit breaker <NUM> generally includes a moving contact <NUM> and a stationary contact <NUM> both disposed within a vacuum arc-extinguishing chamber <NUM>. The stationary contact <NUM> is fixedly mounted in the circuit breaker <NUM> and is unable to move during the operation of the circuit breaker <NUM>. The moving contact <NUM> as illustrated is coupled to a first actuation element <NUM>. When the circuit breaker <NUM> is connected to a main circuit (not shown), the stationary contact <NUM> and the moving contact <NUM> are contacted to each other to form a complete circuit. When a current passing through the circuit breaker <NUM> is detected to be greater than a threshold, the first actuation element <NUM> may be controlled to pull the moving contact <NUM> to disconnect from the stationary contact <NUM> and further move away from the stationary contact <NUM> in a first direction L1. In this way, the moving contact <NUM> and the stationary contact <NUM> can be separated from each other, such that the main circuit is switched off to protect the electrical equipment in the main circuit from being damaged by the excessive current.

In order to allow a good and reliable contact between the stationary contact <NUM> and the moving contact <NUM>, there should be a certain degree of a contact pressure between the stationary contact <NUM> and the moving contact <NUM> when both contacts are coupled to each other. This is achieved by a contact spring <NUM>. With reference to <FIG>, the contact spring <NUM> is arranged within a cylindrical chamber <NUM> of a second actuation element <NUM>, which may be controlled by the control mechanism <NUM>.

The operating principle of the contact spring <NUM> will be described hereinafter. When the circuit breaker <NUM> is switched on, the second actuation element <NUM> is driven to move towards the stationary contact <NUM>. The second actuation element <NUM> causes the contact spring <NUM>, the first actuation element <NUM> and the moving contact <NUM> to move in a direction opposite to the first direction L1. Accordingly, the moving contact <NUM> is coupled to the stationary contact <NUM>. Owing to the contact between the moving contact <NUM> and the stationary contact <NUM>, the moving contact <NUM> cannot continue to move in the direction opposite to the first direction L1. However, the second actuation element <NUM> may further move towards the stationary contact <NUM>, which causes the contact spring <NUM> within the second actuation element <NUM> to be compressed. In this way, the contact pressure is exerted by the contact spring <NUM> onto the moving contact <NUM>. The amount of compression of the contact spring <NUM> is referred to as a stroke of the contact spring <NUM>.

The stroke is an important factor for the circuit breaker <NUM>. For example, the moving contact <NUM> can be firmly coupled to the stationary contact <NUM>. Owing to the presence of the contact pressure, a slight vibration or shaking of circuit breaker <NUM> will not interrupt the electrical connection between the moving contact <NUM> and the stationary contact <NUM>. In addition, even if the moving contact <NUM> and the stationary contact <NUM> are worn out to some extent, the contact pressure allows both of the contacts to remain in good contact during the operation of the circuit breaker <NUM>.

The stroke of the contact spring <NUM> should be adjusted within a proper range. If the stroke is too small, a desired contact pressure would not be ensured, which also influences the switching performance of the circuit breaker <NUM>. If the stroke is too large, the force needed to switch off the circuit breaker <NUM> will be increased. In such a case, the circuit breaker <NUM> may not properly protect the main circuit from being damaged by the large current.

In conventional approaches, the length of the components, such as the second actuation element <NUM>, is provided to be adjustable. For example, a threaded portion may be added to the components to allow the maintenance worker to change the length of the components. In this way, the stroke of the contact spring <NUM> can be adjusted. However, since the components are arranged within the circuit breaker <NUM>, it would make the adjustment of the component more inconvenient. Moreover, since the adjustment may be conducted repeatedly in some cases, such an inconvenience will be more obvious.

An adjusting mechanism <NUM> of the circuit breaker <NUM> according to the present disclosure will be described in detail hereinafter. The adjusting mechanism <NUM> is configured to adjust the stroke of the contact spring <NUM>.

As illustrated in <FIG>, the adjusting mechanism <NUM> generally comprises an operating rod <NUM> and a transmitting rod <NUM> pivotally coupled to the operating rod <NUM>. The operating rod <NUM> is controlled by the control mechanism <NUM> and configured to operate the moving contact <NUM> via the contact spring <NUM>. As illustrated, the contact spring <NUM> is arranged between the operating rod <NUM> and the moving contact <NUM>. The transmitting rod <NUM> is configured to drive the operating rod <NUM> to move towards the stationary contact <NUM> in the direction opposite to the first direction L1. The transmitting rod <NUM> is also configured to drive the operating rod <NUM> to move away from stationary contact <NUM> along the first direction L1. When the current through the circuit breaker <NUM> is detected as being too large, the control mechanism <NUM> will drive the transmitting rod <NUM> to pull the operating rod <NUM> away from the stationary contact <NUM>. As a result, the moving contact <NUM> would be driven away from the stationary contact <NUM> by the operating rod <NUM> to detach from the stationary contact <NUM>, such that the circuit breaker <NUM> is switched off.

As illustrated in <FIG>, the adjusting mechanism <NUM> further includes an adjusting block <NUM> and a bracket <NUM>. The adjusting block <NUM> is pivotally coupled to the transmitting rod <NUM> at a position different from the operating rod <NUM>. As shown in <FIG>, the adjusting block <NUM> comprises a thread hole <NUM> extending along the first direction L1. As shown in <FIG>, the bracket <NUM> includes a first supporting element <NUM> and a second supporting element <NUM> spaced from each other along the first direction L1. The first supporting element <NUM> and the second supporting element <NUM> each includes a through hole <NUM> extending along the first direction L1.

The adjusting mechanism <NUM> further includes an adjusting bolt <NUM>. As best shown in <FIG>, the adjusting bolt <NUM> sequentially extends through the through hole <NUM> of the first supporting element <NUM>, the thread hole <NUM> of the adjusting block <NUM> and the through hole <NUM> of the second supporting element <NUM> along the first direction L1. The adjusting bolt <NUM> comprising an external thread engaging with the thread hole <NUM>. The external thread may be rotated by an external torque to cause the adjusting bolt <NUM> to rotate about its axis A. Accordingly, the adjusting block <NUM> slides along the adjusting bolt <NUM> between the first supporting element <NUM> and the second supporting element <NUM>.

According to example embodiments of the present disclosure, when the adjusting bolt <NUM> is rotated by the external torque, the adjusting bolt <NUM> will not be actuated to move along the first direction L1 or the direction opposite to the first direction L1. Moreover, since the adjusting bolt <NUM> penetrates through the through hole <NUM> of the first supporting element <NUM> and the through hole <NUM> of the second supporting element <NUM>, the adjusting bolt <NUM> will not be actuated to move along a third direction L3 and a second direction L2 normal to the first direction L1. In other words, the adjusting bolt <NUM> can only be driven to rotate about the axis A. Since the adjusting bolt <NUM> is in a threaded connection with the adjusting block <NUM>, the adjusting block <NUM> can be driven along the first direction L1 or the direction opposite to the first direction L1. The position of the adjusting block <NUM> on the adjusting bolt <NUM> can be changed accordingly. As both the adjusting block <NUM> and the operating rod <NUM> are coupled to the transmitting rod <NUM>, the change of the position of the adjusting block <NUM> will cause the change of the position of the operating rod <NUM>, which eventually brings about the change of the stroke of the contact spring <NUM>. In this way, the stroke of the contact spring <NUM> can be adjusted in a convenient manner.

In some example embodiments, as illustrated in <FIG>, the bracket <NUM> may further include a third supporting element <NUM>. The third supporting element <NUM> as illustrated may be arranged between the first supporting element <NUM> and the second supporting element <NUM>. In the shown embodiment, the third supporting element <NUM> is configured to support the adjusting block <NUM> when the adjusting block <NUM> slides between the first supporting element <NUM> and the second supporting element <NUM>. Since the adjusting block <NUM> can be supported by the third supporting element <NUM>, the movement of the adjusting block <NUM> can be achieved in a more reliable manner.

In some example embodiments, as illustrated in <FIG>, the adjusting block <NUM> includes a block body <NUM> and two wings <NUM>. The block body <NUM> as shown is provided with the thread hole <NUM> through which the adjusting bolt <NUM> extends. The wings <NUM> are provided at both sides of the block body <NUM> along the second direction L2 perpendicular to the first direction L1. The wings <NUM> may be supported by the third supporting element <NUM>. The wings <NUM> increase the contact area between the adjusting block <NUM> and the bracket <NUM> to allow the adjusting block <NUM> to move more steadily.

As shown in <FIG>, in some example embodiments, each of the two wings <NUM> may have a height h1 along the third direction L3 perpendicular to the first direction L1 and the second direction L2. The block body <NUM> may have a height h2 along the third direction L3. In the illustrated embodiments, the height h1 of the wings <NUM> may be smaller than the height h2 of the block body <NUM>. In this way, the adjusting block <NUM> can occupy a smaller space within the circuit breaker <NUM>.

In some example embodiments, as shown in <FIG>, each of the two wings <NUM> may comprise a second thread hole <NUM> extending along the third direction L3. Accordingly, as shown in <FIG>, a fastening bolt <NUM> is provided to penetrate through the second thread hole <NUM>. In this way, the adjusting block <NUM> can be mounted onto the third supporting element <NUM> of the bracket <NUM>. The adjustment of the stroke of the contact spring <NUM> can be implemented by a maintenance worker or executed by a robot.

In some embodiments, the second thread hole <NUM> may have a sectional area greater than the fastening bolt <NUM>. In some embodiments, the fastening bolt <NUM> may be used to adjust the position of the adjusting block <NUM>. The fastening bolt <NUM> may be actuated by an external force to cause adjusting block <NUM> to move to a desired position. In other embodiments, a maintenance worker may exert the force via a metal plate to cause the fastening bolt <NUM> to move. In this way, the position of the adjusting block <NUM> can also be adjusted.

In some example embodiments, when the adjusting bolt <NUM> is to be adjusted, the fastening bolt <NUM> should be loosened to allow the relative movement between third supporting element <NUM> and the adjusting block <NUM>. Then, the movement of the transmitting rod <NUM> will cause the operating rod <NUM> to move to a desired position. After the adjusting bolt <NUM> is moved to an appropriate position, the fastening bolt <NUM> would be screwed up. In this way, the stroke of the contact spring <NUM> is adjusted to a desired value.

In some example embodiments, each of the first supporting element <NUM>, the second supporting element <NUM> and the third supporting element <NUM> may comprise a plate. In this manner, the bracket <NUM> can be manufactured in a simple and cost-effective way.

In other example embodiments, the first supporting element <NUM>, the second supporting element <NUM> and the third supporting element <NUM> may be integrally formed as a single piece. In further example embodiments, the first supporting element <NUM>, the second supporting element <NUM> and the third supporting element <NUM> may be integrally formed on a housing of the circuit breaker <NUM>.

In some example embodiments, as illustrated in <FIG>, the adjusting bolt <NUM> may include a bolt head <NUM> and a free end <NUM> opposite to the bolt head <NUM>. The bolt head <NUM> may abut the first supporting element <NUM> while the free end <NUM> abuts the second supporting element <NUM>. In some example embodiments, the free end <NUM> may be coupled to a locknut <NUM>. The locknut <NUM> is configured to rotate along with adjusting bolt <NUM> and can be used to restrict the movement of the adjusting bolt <NUM> along the first direction L1. Since the adjusting bolt <NUM> penetrates through the adjusting block <NUM>, the rotation of the adjusting block <NUM> can be prevented. In this way, the wrapping of the adjusting block <NUM> can be avoided.

Moreover, owing to the fact that the bolt head <NUM> may be rotated continuously, the embodiment allows an automatic adjustment which can be achieved by a robot.

In some example embodiments, a sensor (not shown) may be provided to detect whether the adjusted stroke of the contact spring <NUM> is within the desired range. If the detection shows that the stroke is too large or too small, the adjusting bolt <NUM> may be further adjusted to allow the stroke to fall in the desired range. In some example embodiments, these steps can be automatically carried out by a robot.

In some example embodiments, the bolt head <NUM> may be a hexagonal bolt head. Since the screw pitch of the adjusting bolt <NUM> can be known, the relationship between the moving distance of the adjusting block <NUM> along the first direction L1 and the stroke of the contact spring <NUM> is definite. Thus, the relationship between the rotating degree of the hexagonal bolt head and stroke is also definite. In this way, by only rotating the adjusting bolt <NUM> to a desire degree, the stroke of the contact spring <NUM> can be adjusted precisely.

It is to be understood that the hexagonal bolt head is merely an example, without suggesting any limitation as to the scope of the disclosure. In other example embodiments, other shapes of the bolt head <NUM> can be used.

In some example embodiments, the adjusting bolt <NUM> may include screw thread throughout the circumferential surface from the bolt head <NUM> to the free end <NUM>.

In some example embodiments, as illustrated in <FIG>, the first supporting element <NUM> and the second supporting element <NUM> may be parallel to each other. In this way, the bracket <NUM> can be made more compact. In other example embodiments, both the first supporting element <NUM> and the second supporting element <NUM> may be perpendicular to the third supporting element <NUM>.

In some example embodiments, as shown in <FIG>, the first actuation element <NUM> of the circuit breaker <NUM> may include a protrusion <NUM> and an annular shoulder <NUM>. The protrusion <NUM> may be arranged at one end of the first actuation element <NUM>. The annular shoulder <NUM> may be arranged next to the protrusion <NUM>. As illustrated, the cylindrical chamber <NUM> may be arranged adjacent to an end portion of the second actuation element <NUM>. The cylindrical chamber <NUM> may include an opening <NUM> to allow the protrusion <NUM>, the shoulder <NUM> and the contact spring <NUM> to be contained within the chamber <NUM>. The contact spring <NUM> as illustrated may be provided between the shoulder <NUM> of the first actuation element <NUM> and an inner wall of the cylindrical chamber <NUM>. In this way, once the moving contact <NUM> is driven to touch the stationary contact <NUM>, the shoulder <NUM> is kept stationary. Subsequently, the further movement of the second actuation element <NUM> opposite to the first direction L1 will cause the compression of the contact spring <NUM>.

In some example embodiments, the circuit breaker <NUM> may include three phases. In such an embodiment, each phase may include the adjusting mechanism <NUM> described above. It is to be understood that this is merely an example, without suggesting any limitation as to the scope of the disclosure. In other embodiments, the circuit breaker <NUM> may include other numbers of phases.

Compared with the conventional solution, the adjusting mechanism <NUM> for use with the circuit breaker <NUM> according to example embodiments of the present disclosure to allow the maintenance worker or the robot to carry out a precise, convenient and continuous adjustment of the stroke of the contact spring <NUM>.

Claim 1:
An adjusting mechanism (<NUM>) of a circuit breaker (<NUM>), comprising:
an operating rod (<NUM>) configured to operate a moving contact (<NUM>) of the circuit breaker (<NUM>) via a contact spring (<NUM>) arranged between the operating rod (<NUM>) and the moving contact (<NUM>);
a transmitting rod (<NUM>) pivotally coupled to the operating rod (<NUM>) and configured to drive the operating rod (<NUM>) to move towards or away from a stationary contact (<NUM>) of the circuit breaker (<NUM>); characterised by
an adjusting block (<NUM>) pivotally coupled to the transmitting rod (<NUM>) at a position different from the operating rod (<NUM>) and comprising a thread hole (<NUM>);
a bracket (<NUM>) comprising a first supporting element (<NUM>) and a second supporting element (<NUM>) spaced from the first supporting element (<NUM>) along a first direction (L1), each of the first supporting element (<NUM>) and the second supporting element (<NUM>) comprising a through hole (<NUM>) extending along the first direction (L1); and
an adjusting bolt (<NUM>) extending through the through hole (<NUM>) of the first supporting element (<NUM>), the thread hole (<NUM>) of the adjusting block (<NUM>), and the through hole (<NUM>) of the second supporting element (<NUM>) sequentially along the first direction (L1), the adjusting bolt (<NUM>) comprising an external thread engaging with the thread hole (<NUM>), such that when the adjusting bolt (<NUM>) is actuated to rotate about its axis (A), the adjusting block (<NUM>) slides along the first direction (L1) between the first supporting element (<NUM>) and the second supporting element (<NUM>).