CN109870093B

CN109870093B - Device for measuring engagement depth of moving and static contacts

Info

Publication number: CN109870093B
Application number: CN201711249579.5A
Authority: CN
Inventors: 赖德光; 夏莲; 黄昀
Original assignee: ABB Schweiz AG
Current assignee: ABB Schweiz AG
Priority date: 2017-12-01
Filing date: 2017-12-01
Publication date: 2022-04-19
Anticipated expiration: 2037-12-01
Also published as: CN109870093A

Abstract

The embodiment of the disclosure provides a device for measuring the engagement depth between a moving contact and a fixed contact of a circuit breaker. The device comprises a base including an insertion member adapted to be inserted into a movable contact arm supporting a movable contact, the insertion member including a first end; a movable member movably arranged in the base and adapted to move towards the first end when the movable contact moves towards the stationary contact; and a locking assembly coupled to the base and adapted to lock the movable member to prevent the movable member from moving away from the first end.

Description

Device for measuring engagement depth of moving and static contacts

Technical Field

Embodiments of the present disclosure generally relate to a measuring device, and more particularly, to a device for measuring a depth of engagement between a movable contact and a stationary contact of a circuit breaker.

Background

The switchgear and the equipment therein usually require regular maintenance. For example, it is sometimes necessary to replace or retrofit these devices for better performance. As an example, for a circuit breaker in a switchgear cabinet, there are usually multiple pairs of moving contacts and stationary contacts. The depth of engagement between the moving and stationary contacts of a circuit breaker is a very important parameter during the installation of the circuit breaker in a switchgear cabinet, for example when retrofitting a circuit breaker that has been used for years.

Under normal conditions, the panel of the switch cabinet bearing the fixed contact may deform due to long-term use. In addition, there are always some differences between the pairs of moving and stationary contacts. As a result, incorrect engagement, for example an incorrect engagement depth, between the moving contact and the stationary contact may occur. This may lead to a circuit breaker failure or to personnel injury in severe conditions. For example, an incorrect engagement may cause an increase in the electrical resistance between the moving and stationary contacts, thereby causing the temperature between them to exceed a safe temperature range. This can cause premature failure of the circuit breaker or risk of fire.

Therefore, it is also important to be able to accurately determine the state of engagement between the movable contact and the stationary contact.

Disclosure of Invention

Embodiments of the present disclosure provide a solution for providing a device for measuring the engagement depth between a moving contact and a stationary contact to ensure correct engagement and accurately obtain the engaged state.

In a first aspect of the present disclosure, an apparatus for measuring a depth of engagement between a movable contact and a stationary contact of a circuit breaker is provided. The device comprises a base including an insertion member adapted to be inserted into a movable contact arm supporting a movable contact, the insertion member including a first end; a movable member movably arranged in the base and adapted to move towards the first end when the movable contact moves towards the stationary contact; and a locking assembly coupled to the base and adapted to lock the movable member to prevent the movable member from moving away from the first end.

In some embodiments, the locking assembly comprises a locking buckle comprising a first locking finger; and the movable member includes a plurality of lateral grooves arranged in an axial direction of the movable member; wherein the first locking finger is insertable into one of the plurality of transverse slots to lock the movable member.

In some embodiments, the locking assembly further comprises a second locking finger and a retaining member for retaining the first locking finger in one of the plurality of transverse slots by applying a force between the retaining member and the second locking finger.

In some embodiments, each transverse slot of the plurality of transverse slots comprises an oblique side and a vertical side in the axial direction, wherein the oblique side is adapted to cause the first locking finger to move out of the transverse slot and into the next transverse slot along the oblique side when the movable member is moved towards the first end.

In some embodiments, the vertical side is adapted to prevent the movable member from moving away from the first end.

In some embodiments, the base includes a stop member adjacent an end opposite the first end for providing a stop for movement of the base toward the movable contact arm.

In some embodiments, the spacing member includes a mounting slot, and the locking buckle is pivotably coupled within the mounting slot via a pivot.

In some embodiments, the mounting slot comprises walls opposite each other, wherein the pivot is fixed perpendicularly between the walls, and the device further comprises a cover for covering the mounting slot in a direction perpendicular to the axial direction.

In some embodiments, the retaining member is disposed between the cover and the wall.

In some embodiments, the device further comprises a sealing member disposed at the first end to at least partially seal the inner bore of the base.

In some embodiments, the device further comprises a resilient member disposed between the sealing member and the movable member to apply a compressive force therebetween.

In some embodiments, the apparatus further comprises a scale formed on a side of the movable member perpendicular to the axial direction.

In some embodiments, the device further comprises a ring groove formed on an outer periphery of the insert member for receiving the O-ring to provide a tight fit between the O-ring and the movable contact arm.

In a second aspect of the present disclosure, a method of manufacturing the above-described device is provided.

In a third aspect of the disclosure, a method of using the apparatus described above is provided.

It should be understood that this summary is not intended to identify key or essential features of the embodiments of the disclosure, nor is it intended to be used to limit the scope of the disclosure. Other features of the present disclosure will become readily apparent from the following description.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout the exemplary embodiments of the present disclosure.

Fig. 1 illustrates a conventional circuit breaker, in which an enlarged view of an engagement portion of a movable contact and a stationary contact is shown;

fig. 2 shows an isometric view of a device according to an embodiment of the present disclosure;

FIG. 3 shows a side view of an apparatus according to an embodiment of the present disclosure;

fig. 4 shows an exploded view of a device according to an embodiment of the present disclosure;

FIG. 5 shows a cross-sectional view of section A-A of an apparatus according to an embodiment of the disclosure in FIG. 3;

FIG. 6 shows an enlarged view of portion C of the device according to the embodiment of the present disclosure of FIG. 5;

FIG. 7 shows a cross-sectional view of an apparatus according to another embodiment of the present disclosure;

FIG. 8 shows an isometric view of a device according to an embodiment of the present disclosure from another angle;

FIG. 9 shows a side view of a base according to an embodiment of the present disclosure;

FIG. 10 shows a cross-sectional view of section D-D of an apparatus according to an embodiment of the disclosure in FIG. 9;

fig. 11 shows a view when measuring the engagement depth of the movable contact and the stationary contact;

figure 12 illustrates a side view of a device according to an embodiment of the present disclosure prior to insertion into a movable contact arm of a circuit breaker;

fig. 13 shows a side view of the movable contact arm of the circuit breaker;

figure 14 illustrates a cross-sectional view of section B-B of the movable contact arm of the circuit breaker of figure 13 with a device inserted into the movable contact according to an embodiment of the present disclosure;

fig. 15 shows a cross-sectional view of a device according to an embodiment of the present disclosure before the moving and stationary contacts are engaged; and

fig. 16 illustrates a cross-sectional view of a device according to an embodiment of the present disclosure after engagement of the movable and stationary contacts.

The same or similar reference numbers will be used throughout the drawings to refer to the same or like elements.

Detailed Description

The present disclosure will now be described with reference to several example embodiments. It should be understood that these examples are described only for the purpose of enabling those skilled in the art to better understand and thereby enable the present disclosure, and are not intended to set forth any limitations on the scope of the technical solutions of the present disclosure.

As used herein, the term "include" and its variants are to be read as open-ended terms meaning "including, but not limited to. The term "based on" will be read as "based at least in part on". The terms "one embodiment" and "an embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment". The terms "first," "second," and the like may refer to different or the same object. Other explicit and implicit definitions may be included below. The definitions of the terms are consistent throughout the specification unless the context clearly dictates otherwise.

Fig. 1 illustrates a conventional circuit breaker, in which an enlarged view of an engagement portion of a movable contact and a stationary contact is shown. Generally speaking, when the moving contact and the static contact are engaged, the engagement requirement is satisfied as long as the chamfered surface of the static contact 202 passes over the highest point of the quincunx contact finger 204 of the moving contact 201, as shown in the enlarged view of fig. 1. One index for determining whether the engagement requirement is met is an engagement depth H, which corresponds to a depth of the stationary contact 202 entering the quincunx contact finger 204 of the movable contact 201.

However, as shown in fig. 1, the space between the movable contact 201 and the fixed contact 202 of the circuit breaker 200 is generally very narrow. Therefore, it is very difficult to determine the engagement depth H of the movable contact 201 and the fixed contact 202 of the circuit breaker 200. Conventionally, an operator must visually check the engagement depth H to determine the engagement state between the movable contact 201 and the stationary contact 202, which is an error-prone process. Furthermore, users such as operators are often unable to detect some small errors in occlusion, resulting in improper occlusion. In some severe conditions, improper engagement between the movable contact 201 and the fixed contact 202 may cause a circuit breaker failure and personal injury.

In order to enable an effective and accurate inspection, embodiments of the present disclosure provide an apparatus 100 for measuring a depth of engagement H between a movable contact 201 and a stationary contact 202 of a circuit breaker 200. Some exemplary embodiments will now be described with reference to fig. 2 to 10.

Fig. 2 shows an isometric view of a device according to an embodiment of the present disclosure; FIG. 3 shows a side view of an apparatus according to an embodiment of the present disclosure; fig. 4 shows an exploded view of a device according to an embodiment of the present disclosure; FIG. 5 shows a cross-sectional view of section A-A of an apparatus according to an embodiment of the disclosure in FIG. 3; FIG. 6 shows an enlarged view of portion C of the device according to the embodiment of the present disclosure of FIG. 5; FIG. 7 shows a cross-sectional view of an apparatus according to another embodiment of the present disclosure; FIG. 8 shows an isometric view of a device according to an embodiment of the present disclosure from another angle; FIG. 9 shows a side view of a base according to an embodiment of the present disclosure; and figure 10 shows a cross-sectional view of a D-D section of the device according to the embodiment of the disclosure in figure 9.

As shown in fig. 2, 3 and 4, an apparatus 100 according to an embodiment of the present disclosure generally includes a base 101, a movable member 102 and a locking assembly 103. In some embodiments, the base 101 may be a hollow cylinder including an insert 111, the insert 111 having a first end 1110 and a second end 1111 opposite one another. The insertion member 111 may be inserted into the movable contact arm 203 supporting the movable contact 201. Wherein the first end 1110 is an end located in the insertion direction of the insertion part 111, and the second end 1111 is an end distant from the insertion direction of the insertion part 111.

In some embodiments, the outer end face of the movable component 102 inserted in position to be measured may be flush with the outer end face of the tulip finger 204 of the movable contact 201, as shown in fig. 13. In some embodiments, the outer end surface of the inserted movable component 102 may protrude from the outer end surface of the tulip contact finger 204 or be recessed relative to the outer end surface of the tulip contact finger 204.

The movable member 102 is movably arranged in the base 101. When the movable contact 201 moves towards the fixed contact 202, i.e. when the fixed contact 202 enters the quincunx contact finger 204 of the movable contact 201 or when the fixed contact 202 contacts the movable component 102, the movable component 102 may move towards the first end 1110 as the movable contact 201 continues to move. The locking assembly 103 is coupled to the base 101 and can lock the movable member to prevent the movable member from moving away from the first end 1110.

It should be understood that, according to the embodiments of the present disclosure, the movable component 102 moves synchronously with the movement of the movable contact 201 toward the stationary contact 202. In this way, when the movable contact 201 reaches the final engagement position, as shown in fig. 11, the engagement depth H between the movable contact 201 and the stationary contact 202 can be accurately determined by checking the relative distance between the movable part 102 and the first end 1110 of the base 101. In this way, a proper engagement between the movable contact 201 and the stationary contact 202 can be ensured, which further ensures the safety of use of the circuit breaker 200.

In some embodiments, as shown in fig. 5, the base 101 further includes a stop feature 112, the stop feature 112 abutting the second end 1111 of the insert feature 111. In some embodiments, the stop component 112 and the insert component 111 are integrally formed. For example, by machining or molding. In other embodiments, the stop member 112 and the insertion member 111 may be formed separately and joined together by means known in the art, such as welding, to form a unitary structure.

In some embodiments, the contact arm 203 has a central aperture 205 for receiving the device 100. The insertion member 111 is inserted into the inner bore 119. The stopper member 112 serves to provide a stopper for the movement of the base 101 toward the movable contact arm 203. Here, the limit position means that after the base 101 moves a certain distance toward the movable contact arm 203, for example, when the limit member 112 contacts the outer end surface of the movable contact arm 203, the limit member 112 can prevent the base 101 from moving further toward the movable contact arm 203. The arrangement can further ensure the accuracy of measurement.

In some embodiments, as shown in fig. 8 and 10, the stop member 112 may be formed in a polygonal shape, such as a square or hexagon, to enable a tool to act on the stop member 112 to facilitate insertion and removal of the base 101 into and from the central bore 205.

In some embodiments, a scale 122 may be formed on one side of the movable member 102. With the scale 122, a user such as an operator can intuitively and easily determine the engagement depth H between the movable contact 201 and the stationary contact 202 by reading the value on the scale 122. As described above, in some embodiments, the outer end face of the movable component 102 inserted in position to be measured may be flush with the outer end face of the tulip finger 204 of the movable contact 201. In this case, the initial value at the time when the scale 122 starts moving may be set to 0mm, and the size displayed on the scale 122 obtained after the measurement is the bite depth H.

In some embodiments, the outer end face of the movable component 102 inserted to be measured may protrude from the outer end face of the tulip contact finger 204 or be recessed relative to the outer end face of the tulip contact finger 204. In this case, the initial value of the scale 122 may be adjusted so that the measurement result can appropriately display the bite depth H. For example, in a case where the outer end face of the movable member 102 inserted to be measured is recessed by 5mm with respect to the outer end face of the tulip finger 204, the initial value of the scale 122 may be set to 5mm, and the dimension displayed on the scale 122 obtained after the measurement is the bite depth H.

As shown in fig. 4 and 5, in some embodiments, the movable member 102 may be cylindrical. In the axial direction "D" of the movable member, a plurality of lateral grooves 108 may be formed on one side (referred to as "first side") of the movable member 102. In some embodiments, the scale 122 is formed on an opposite side (referred to as the "second side"), thereby providing an intuitive bite depth H for the operator.

In some embodiments, referring to fig. 8, the second side can be ground or machined to a flat surface to facilitate forming the scale 122. The side of the inner bore 119 adjacent the second side is correspondingly flat so as to cooperate with the flat second side to prevent the movable member 101 from tipping over within the inner bore 119. In some embodiments, only a portion of the sides of the bore 119 may be machined to be flat, as will be described in more detail in later embodiments.

It should be understood that in some cases, scale 122 may be omitted. For example, in some embodiments, the transverse grooves 108 may function as a scale, thereby eliminating the need to separately form the scale.

In some embodiments, locking assembly 103 includes a locking buckle 104 having two locking fingers (referred to as first locking finger 105 and second locking finger 106, respectively, for ease of discussion). As shown in fig. 4, a first locking finger 105 and a second locking finger 106 are formed on opposite ends of the locking buckle 104. As shown in fig. 6, the first locking finger 105 may be inserted into one of the plurality of lateral grooves 108 so that the movable member 102 may be locked. Therefore, the bite depth H can be maintained, so that the operator can determine the bite state by reading the bite depth H on the scale 122.

Referring to fig. 5 and 6, in some embodiments, the first locking finger 105 may be retained in either of the transverse slots 108 by a retaining feature 107 of the locking assembly 103. Specifically, in these embodiments, first locking finger 105 is held in place by a force "F" applied to second locking finger 106 by retaining member 107. In some embodiments, the force "F" may be an attractive force applied to the second locking finger 106. For example, when the measurement is completed, i.e. when the movable contacts 201 reach the final engagement position, the first locking fingers 105 can be retained in the respective transverse slots 108. Accordingly, the scale 122 is held for reading by a user (e.g., an operator).

The retaining member 107 may be implemented as any suitable mechanism adapted to apply an attractive force to the second locking finger 106. For example, in some embodiments, the retaining component 107 may include a magnetic element, and the second locking finger 106 may be a material that is attracted by the magnetic element, such as iron or steel. Thus, the force "F" may be applied by causing the magnetic element to attract the second locking finger 106. Alternatively or additionally, in some embodiments, the retaining member 107 may include a resilient element, such as a spring, that may provide an attractive force to the retaining member 107.

In some embodiments, the locking buckle 104 is pivotably coupled to the stop feature 112 of the base 101. More specifically, as shown in fig. 4, in some embodiments, the locking buckle 104 may be pivotably coupled in a mounting slot 114 formed in the stop component 112 by a pivot 115. Thus, the holding member 107 forms a lever with its fulcrum at the pivot 115. In this manner, a force "F" applied to second locking finger 106 can cause first locking finger 105 to be inserted into transverse slot 108. In some embodiments, pivot 115 may be a bolt coupled with nut 124, as shown in FIG. 4. Thus, the locking buckle 104 can be easily assembled by coupling the nut 124 to the bolt. Of course, it should be understood that the pivot 115 may take other forms, such as a rivet, etc.

When the operator presses the second locking finger 106 in a direction opposite to the force "F", the first locking finger can be removed from the transverse slot 108. This allows the movable part 102 to move freely along the base 101. In this way, the operator may return the movable part to the initial position after the measurement by pressing the second locking finger 106, which will be discussed in detail below.

In practice, it may be desirable to prevent the movable member 102 from moving to the opposite direction to prevent erroneous measurements from occurring. In other words, the movable part 102 should move only in one direction during the measurement. To this end, in some embodiments, the transverse slots 108 may each include an oblique side 109 and a perpendicular side 110 opposite each other in the axial direction "D" of the movable member 102. For example, as shown in FIG. 6, the angled side 109 can be the side away from the first end 1110. In this manner, as the movable member 102 moves toward the first end 1110, the first locking finger 105 may move out of one transverse slot 108 and into the next transverse slot along the angled side 109.

On the other hand, the vertical side 110 may prevent the movable member 102 from moving away from the first end 1110. In other words, the movable member 102 can only move in one direction during the measurement so that the measured bite depth can be maintained. Therefore, the accuracy of measurement can be ensured.

In some embodiments, the mounting slots 114 may have walls 116 that oppose each other. A hole 125 may be formed in each wall 116 for the pivot 115 to pass through. In some embodiments, a cover 117 may be provided in order to cover the mounting groove 114 in a direction perpendicular to the axial direction "D". In some embodiments, the cover 117 may be a U-shaped member having two vertical sides and a flat surface therebetween. In some embodiments, each of the two vertical sides is formed with an opening 126 therethrough.

The mounting groove may be covered by a flat surface of the cover 117. At the same time, the vertical edge of the cover 117 may cover at least a portion of the outside of the wall 116, with the opening 126 concentric with the hole 125. In this way, the cover 117 may be secured to the wall 116 of the mounting slot 114 via the pivot 115.

In some embodiments, as shown in fig. 4, the retaining member 107 may be disposed between the cover 117 and the wall 116. In this way, the holding member 107 is retained by the cover 117 and the wall 116. In some embodiments, notches 127 may be formed in appropriate locations of wall 116 (e.g., the outer corners of wall 116). The shape of the recess 127 may match the shape of the holding member 107 so that the opposite end of the holding member 107 may be placed in the recess 127 on its upper side.

In operation, as shown in fig. 12-16, prior to measurement, an operator may insert the insertion member 111 of the base 101 into the central aperture 205 of the movable contact arm 203. After being inserted to the predetermined position, the stopper member 112 can prevent the base 101 from moving further toward the movable contact arm 203.

The stopper part 112 may be larger in size than the center hole 205 of the movable contact arm 203. In this way, the base 101 can be restrained at a position where the stopper part 112 reaches the outer end of the center hole 205. In some embodiments, the insert member 111 may have a substantially uniform diameter that is slightly smaller than the diameter of the central bore 205. In this way, the insertion part 111 can be inserted into the center hole 205.

Additionally, to achieve a tight fit between the insert member 111 and the central bore 205, one or more O-rings 121 may be disposed on the outer circumference of the insert member 111. The diameter of the O-ring 121 may be slightly larger than the diameter of the central bore 205 so as to prevent the insertion member 111, and thus the entire device 100, from slipping out of the central bore 205.

In some embodiments, one or more circumferential grooves 120 may be formed on the outer circumference of the insert member 111. In this manner, the O-ring 121 may be received in the ring groove 120, such that inadvertent movement of the O-ring 121 along the outer periphery of the base 101 may be prevented.

It should be understood that the base 101 may be inserted into the central bore 105 in other ways than those described above. By way of example only, in some embodiments, external threads (not shown) may be formed on the exterior of the insert member 111 and internal threads may be formed on the inner circumference of the central bore 105. In this way, the base 100 is inserted into the central hole 105 by screwing the insertion member 111 into the central hole 105. Further, it should be understood that the base 101 may be inserted into the central bore 105 by any other suitable means.

As described above, the base 101 may be a hollow cylinder and have an internal bore 119 for receiving the movable member 101. In some embodiments, a sealing member 118 may be disposed at the first end 1110 to at least partially seal the internal bore 119.

As shown in fig. 5, in some embodiments, a resilient member 123 is disposed between the sealing member 118 and the movable member 102 to apply a compressive force therebetween. In this way, after the end of the measurement, by pressing the second locking finger 112, the movable member 102 can be ejected to the initial position due to the compressive force. By way of example only, the resilient member 123 may be a compression spring. However, it should be understood that the resilient member 123 may take other forms. To prevent the movable member 102 from falling out of the internal bore 119 when expelled by the compressive force, the movable member 102 may in some embodiments be formed with a run-off prevention portion 128 at one end. In some embodiments, the anti-run out portion 128 may be formed on a side of the movable member 102 adjacent to the sealing member. It is described in the above embodiment that the movable member 102 may be processed into a flat surface on one side thereof so as to set the scale 122. In these embodiments, the run-off prevention portion 128 may be a portion of the movable member 102 that is not planar, as shown in fig. 5 or 7.

Further, as can be seen from fig. 8, 9 and 10, in some embodiments, the inner bore 119 may communicate with the mounting slot 114 at a portion corresponding to the spacing member 112. In other words, the portion of the internal bore 119 corresponding to the stop member 112 is an extension of the mounting slot 114. Further, in some embodiments, only the bottom surface of the portion of the internal bore 119 is provided as a flat surface to mate with a flat side of the movable member 102 to prevent the movable member 102 from flipping within the internal bore 119. In these embodiments, the side of the portion of the inner bore 119 corresponding to the insertion part 111 may not be machined flat, as shown in fig. 9 and 10. This arrangement can effectively avoid the occurrence of unnecessary turning of the movable member 102 in the inner hole 119, and can also reduce the processing strength of the base 101 and the assembling strength of the entire apparatus 100.

It should be understood that, in the above embodiment, the portion of the inner hole 119 corresponding to the stopper member 112 has the same width as the mounting groove 114, which is smaller than the diameter of the portion of the inner hole 119 corresponding to the insertion member 111. This effectively causes the retaining portion 128 of the movable member 102 to be restrained, thereby preventing the movable member 102 from slipping out.

In some embodiments, as shown in fig. 7, the elastic member 123 may be omitted, and an O-ring 129 may be provided on the outer circumference of the coming-off prevention portion 128. The outer diameter of the O-ring 129 may be slightly larger than the diameter of the internal bore 119 to provide a tight fit between the O-ring 129 and the internal bore 119. In this manner, the moveable member 102 may be held in any suitable position within the bore 119 and the moveable member 102 may be drawn to an initial position after the measurement is completed.

When using the device 100, a user, such as an operator, may insert the device 100 into the central bore 205 of the movable contact arm 203 until the stop member 112 reaches the outer end of the central bore 205. Due to the tight fit between the O-ring and the central bore 205, the device 100 may be held in place, as shown in fig. 13 and 14. In this way, the device 100 is ready to take a measurement, as shown in fig. 15.

The circuit breaker 200 can then be installed in a switchgear cabinet, whereby the moving contact 201 continues to move until it is in place when the stationary contact 202 enters the tulip contact finger 204 of the moving contact 201 or when the stationary contact 202 touches the movable part 102. In this process, the movable member 102 moves toward the first end 1110 with the movement of the movable contact arm 203, as shown in fig. 16. After the movable contact 201 is in position, the movable part 102 is locked by the locking assembly 103 for inspection.

Next, the circuit breaker 200 is removed from the switchgear, thereby moving the moving contacts 201 out of the interface 206. The device 100 is then pulled or screwed out of the central hole 205, and the depth of engagement H between the movable contact 201 and the stationary contact 202 can then be determined by checking the scale 122. Thereafter, the operator may press the second locking finger 106 to release the movable part 102 in preparation for the next measurement.

As can be seen from the above embodiments of the present disclosure, the device 100 according to the present disclosure can accurately and easily obtain the engagement state of the movable contact 201 and the fixed contact 202. This ensures safe use of the circuit breaker 200 and the electrical appliance connected thereto.

It is to be understood that the above detailed embodiments of the disclosure are merely illustrative of or explaining the principles of the disclosure and are not limiting of the disclosure. Therefore, any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. Also, it is intended that the appended claims cover all such changes and modifications that fall within the true scope and range of equivalents of the claims.

Claims

1. Device (100) for measuring the depth of engagement between a movable contact (201) and a stationary contact (202) of a circuit breaker (200), comprising:

a base (101) comprising an inner bore (119), an insertion member (111) and a stop member (112), the insertion member (111) being adapted to be inserted into a movable contact arm (203) supporting the movable contact (201), the insertion member (111) comprising a first end (1110) and a second end (1111), the stop member (112) being in abutment with the second end (1111), the stop member (112) being for providing a stop for movement of the base (101) towards the movable contact arm (203);

a movable part (102) movably arranged in the base (101) and protruding from an end of the stop part (112) away from the insertion part (111), and adapted to be directly touched by the stationary contact (202) to move towards the first end (1110) when the movable contact (201) moves towards the stationary contact (202); and

a locking assembly (103) coupled to the restraining member (112) of the base (101) and adapted to lock the movable member (102) to prevent movement of the movable member (102) away from the first end (1110),

wherein the locking assembly (103) comprises a locking buckle (104), the locking buckle (104) comprising a first locking finger (105); and is

The movable part (102) includes a retaining portion (128) formed at one end and a plurality of lateral grooves (108) arranged in an axial direction (D) of the movable part (102);

wherein the first locking finger (105) is insertable into one of the plurality of transverse slots (108) to lock the movable member (102),

when the movable contact (201) moves towards the fixed contact (202), the fixed contact (202) directly pushes one end of the movable component (102) close to the plurality of transverse grooves (108) so that the anti-falling part (128) moves in the direction from the plurality of transverse grooves (108) to the anti-falling part (128) in the inner hole (119).

2. The device (100) of claim 1,

wherein the locking assembly (103) further comprises a second locking finger (106) and a retaining member (107) for retaining the first locking finger (105) in one of the plurality of transverse slots (108) by applying a force (F) between the retaining member (107) and the second locking finger (106).

3. The device (100) of claim 2,

wherein each transverse slot of the plurality of transverse slots (108) comprises in the axial direction (D) an inclined side (109) and a vertical side (110);

wherein the inclined side (109) is adapted to move the first locking finger (105) out of a transverse slot and into a next transverse slot along the inclined side (109) when the movable member (102) is moved towards the first end (1110).

4. The device (100) of claim 3,

wherein the vertical side (110) is adapted to prevent the movable member (102) from moving away from the first end (1110).

5. The device (100) of claim 2,

wherein the stop member (112) comprises a mounting slot (114), the locking buckle (104) being pivotably coupled within the mounting slot (114) via a pivot (115).

6. The device (100) of claim 5,

wherein the mounting groove (114) comprises walls (116) opposite to each other, wherein the pivot (115) is vertically fixed between the walls (116), and

the device (100) further comprises a cover (117) for covering the mounting groove (114) in a direction perpendicular to the axial direction (D).

7. The device (100) of claim 6,

wherein the retaining member (107) is arranged between the cover (117) and the wall (116).

8. The apparatus (100) of claim 1, further comprising:

a sealing member (118) disposed at the first end (1110) to at least partially seal an inner bore (119) of the base (101).

9. The apparatus (100) of claim 8, further comprising:

an elastic member (123), the elastic member (123) being disposed between the sealing member (118) and the movable member (102) to apply a compressive force therebetween.

10. The apparatus (100) of claim 1, further comprising:

a scale (122), the scale (122) being formed on a side of the movable member (102) perpendicular to the axial direction (D).

11. The apparatus (100) of claim 4, further comprising:

an annular groove (120), the annular groove (120) being formed on an outer circumference of the insertion part (111) for receiving an O-ring (121) to provide a tight fit between the O-ring (121) and the movable contact arm (203).

12. A method of manufacturing a device (100) according to any one of claims 1-11.

13. A method of using the apparatus (100) according to any one of claims 1-11.