CN215009271U - Interlocking mechanism for a switching device and switching device - Google Patents

Abstract

The utility model relates to an interlocking device and switching device for switching device. The switching device includes: the cabinet comprises a cabinet body and a cabinet door which can be opened and closed, wherein a secondary socket is arranged in the cabinet body; the handcart can enter and exit the cabinet body and is provided with a secondary plug detachably connected with the secondary socket, and the handcart is provided with a test position and a working position; the interlocking mechanism includes: the support is arranged in the cabinet body; an interlock member movably coupled to the support and having a first end facing the cabinet door and a second end facing the secondary receptacle; a stop member in follower engagement with the interlock member; the interlocking mechanism comprises an interlocking gesture when the handcart is at a test position and the secondary socket is not jointed with the secondary plug and an avoiding gesture when the handcart is at the test position and the secondary socket is jointed with the secondary plug; in the interlocking posture, the first end of the interlocking piece is matched with the door closing stop, and the stop piece is matched with the handcart in the stop way along the direction of entering the cabinet body; in the avoiding posture, the first end of the interlocking piece enables the cabinet door to be opened, and the stop piece enables the handcart to be opened in response to the movement of the interlocking piece.

Description

Interlocking mechanism for a switching device and switching device

Technical Field

The utility model relates to an electrical equipment technical field especially relates to an interlocking device and switching device for switching device.

Background

A handcart type switching device (also called a withdrawable switching device) is widely used due to advantages of convenience in maintenance, reliability in power supply, and the like, and generally includes a fixed cabinet and a handcart which can enter and exit the cabinet. The handcart is generally mainly provided with primary electric elements such as a circuit breaker, a mutual inductor and the like, and is used for being connected with the electric elements in the cabinet to form a primary loop. The hand truck has three positions relative to the cabinet, namely a working position, a testing position and a disconnection position (also called a maintenance position). Wherein the hand truck in the disconnected position is removed from the cabinet without any connection to the electrical components within the cabinet. In the testing position, the hand truck is pushed into the cabinet, the primary circuit is not yet conducted, and a secondary plug on the hand truck can be engaged with a secondary socket in the cabinet to conduct the secondary circuit. In the working position, the handcart is pushed further into the cabinet compared with the test position, and the primary loop and the secondary loop are all conducted.

The secondary protection is vital to the switching device, especially the high-voltage switching device, and the electrical interlocking and the protection of the switching device can only be operated after the secondary circuit is conducted, and when the switching device or associated equipment breaks down, the protection system can act immediately, so that the safety of operators and equipment facilities is effectively protected. Therefore, the switching device needs to be provided with a corresponding misoperation prevention mechanism to prohibit the handcart from being pushed to the working position under the condition that the secondary plug is not jointed with the secondary socket.

SUMMERY OF THE UTILITY MODEL

The present invention aims to provide an interlocking mechanism for a switching device that can solve at least the above-mentioned partial problems.

The utility model discloses still aim at providing an use above-mentioned modified interlocking device's switching device.

According to an aspect of the present invention, there is provided

An interlock mechanism for a switching device, wherein the switching device comprises: the cabinet is provided with a cabinet body and a cabinet door capable of opening and closing the cabinet body, wherein a secondary socket is arranged in the cabinet body; a hand truck movable into and out of the cabinet body and provided with a secondary plug detachably engageable with the secondary socket, wherein the hand truck has a testing position and a working position within the cabinet body; wherein, the interlocking mechanism includes: the support is arranged in the cabinet body; an interlock movably connected to the support and having a first end facing the cabinet door and a second end facing the secondary receptacle; a stopper follow-up engaged to the interlocking member; the interlocking mechanism is provided with an interlocking gesture under the condition that the handcart is at a test position and the secondary socket is not jointed with the secondary plug, and an avoiding gesture under the condition that the handcart is at the test position and the secondary socket is jointed with the secondary plug; in the interlocking posture, the first end of the interlocking piece is matched with the door closing stop block formed by the cabinet door, and the stop block is matched with the handcart in the stop block direction entering the cabinet body; under dodging the gesture, the first end of interlocking piece lets out the cabinet door, just the stop part responds to the motion of interlocking piece lets out the handcart.

According to the interlocking mechanism provided by the embodiment, by means of mutual matching of the interlocking piece, the support and the stop piece, the on-state of the secondary circuit, the handcart position and the interlocking of the opening and closing of the cabinet door are realized, namely when the trolley is in the test position but the secondary circuit is not on, the cabinet door cannot be closed and the handcart cannot continue to be pushed. Until the secondary circuit is conducted, the interlocking is released, the handcart is allowed to continue to be pushed to the working position, and the cabinet door can be closed. Therefore, whether the secondary circuit of a worker is conducted or not can be intuitively reminded, the condition that the handcart is pushed into a working position due to the fact that the secondary plug is not jointed with the secondary socket yet caused by negligence is avoided, and the safety of the switching device is improved. The interlocking function can be realized only by means of the mutual matching of the interlocking piece, the support and the stop piece, the structure is simple and easy to implement, the occupied space is small, the economic benefit is good, the applicability of the interlocking mechanism is improved, and the interlocking mechanism can be applied to even a switch device with a small size or an internal space.

In some embodiments, the interlock is arranged such that during movement of the hand truck in a direction into the cabinet body to the testing position, the interlock contacts and is driven by the hand truck to engage the first end with the cabinet door to form a door closing stop. This embodiment provides a simple way of correlating the hand truck position to the attitude of the interlock, i.e. the hand truck directly contacts and drives the interlock to move, to control the attitude switch of the interlock.

In some embodiments, the interlock is provided with pivotable rollers that form a rolling friction fit with the hand truck during movement of the hand truck in a direction into the cabinet to the testing position. The technical scheme of this embodiment can effectively reduce the friction between interlocking piece and the handcart, when guaranteeing that the handcart can rely on the contact to drive interlocking piece switching gesture, reduces the wearing and tearing of the component that bring because of contact friction.

In some embodiments, the interlocking member is arranged such that: in the interlocked position, the second end approaches the secondary receptacle at a distance sufficient to interfere with engagement of the secondary plug to the secondary receptacle; during the time that the secondary plug is close to and engages the secondary socket, the second end is driven by the secondary plug to cause the first end to give way to the cabinet door. According to the technical scheme of the embodiment, whether the secondary circuit is conducted or not is ensured to be related to the posture conversion of the interlocking piece, and then the continuous propulsion of the trolley and the closing of the cabinet door are controlled.

In some embodiments, one of the support and the stop has a vertical groove, the other has an opening, a pin is penetrated in opening and the vertical groove, wherein, during the interlocking piece moves to its first end and lets out the cabinet door, the stop is promoted by the interlocking piece and follows the vertical groove shifts up to let out the handcart, and during the interlocking piece moves to first end with the cabinet door forms the backstop cooperation of closing the door, the stop is located vertical groove lower extreme and with the handcart forms the backstop cooperation. According to the technical scheme of this embodiment, the stopper and the interlocking piece form two components and have the linkage relation each other to realize the interlocking of secondary conduction return circuit, dolly position and cabinet door.

In some embodiments, the interlocking member comprises: a first plate segment pivotally connected to the support; a second plate segment angularly connected to the first plate segment; wherein an end of the first plate segment remote from the second plate segment defines the first end of the interlock and an end of the second plate segment remote from the first plate segment defines the second end of the interlock. According to the embodiment, the interlocking piece which is simple in structure and easy to implement is provided, the cost can be effectively controlled, and the occupied space can be reduced. In addition, the pivotal connection enables the interlocking member to minimize the space occupied by the interlocking mechanism due to the various travel requirements of the first and second ends while meeting the travel requirements, thereby improving the applicability of the interlocking mechanism in various size switching devices.

In some embodiments, the interlock mechanism further has a rest position in which the first end of the interlock member leaves the cabinet door open, in a state where the hand truck has not entered the test position.

In some embodiments, the support is provided with a limiting member, and the interlocking member abuts against the limiting member under the action of gravity in the standing posture.

According to another aspect of the present invention, there is provided a switching device, including: the cabinet is provided with a cabinet body and a cabinet door capable of opening and closing the cabinet body, wherein a secondary socket is arranged in the cabinet body; a hand truck movable into and out of the cabinet body and provided with a secondary plug detachably engageable with the secondary socket, wherein the hand truck has a testing position and a working position within the cabinet body; wherein, the switching device also comprises the interlocking mechanism.

In some embodiments, the door has a projection extending toward an interior of the cabinet for forming a door closing stop with the first end of the interlock.

Additional features and advantages of the invention will be set forth in part in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following, or may be learned from the practice of the invention.

Drawings

Embodiments of the present invention are described in detail below with reference to the attached drawing figures, wherein:

fig. 1 is a schematic view of a cabinet and an interlocking mechanism according to an embodiment of the present invention, wherein the interlocking mechanism is in a resting position;

FIG. 2 is an enlarged view at A of FIG. 1;

fig. 3 is a schematic diagram of a hand truck and an interlock mechanism according to an embodiment of the present invention, wherein the interlock mechanism is in an interlock attitude;

FIG. 4 is an enlarged view at B of FIG. 3;

fig. 5 is a schematic diagram of a hand truck and an interlock mechanism in accordance with an embodiment of the present invention, wherein the interlock mechanism is in an avoidance attitude;

FIG. 6 is an enlarged view at C of FIG. 5;

fig. 7 is a schematic diagram of a hand truck and an interlock mechanism in which the interlock mechanism is in an avoidance attitude and the hand truck is advanced to an operating position in accordance with an embodiment of the present invention.

Description of reference numerals:

1. a switching device; 2. a cabinet; 21. a cabinet body; 22. a cabinet door; 221. a protrusion; 3. a handcart; 31. secondary plug; 4. an interlock mechanism; 41. a support; 411. a first seat body; 412. a second seat body; 413. a limiting member; 42. an interlock member; 421. a rolling member; 422. a first plate section; 423. a second plate section; 424. a first end; 425. a second end; 426. a pivotal shaft; 43. a stopper; 5. secondary socket

Detailed Description

Referring now to the drawings, illustrative aspects of the disclosed interlock mechanism and switchgear used therewith will be described in detail. Although the drawings are provided to present some embodiments of the invention, the drawings are not necessarily to scale of particular embodiments, and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the disclosure of the present invention. The position of some components in the drawings can be adjusted according to actual requirements on the premise of not influencing the technical effect. The appearances of the phrase "in the drawings" or similar language in the specification are not necessarily referring to all drawings or examples.

Certain directional terms used hereinafter to describe the drawings, such as "inner", "outer", "above", "below", and other directional terms, will be understood to have their normal meaning and refer to those directions as they normally relate to when viewing the drawings. Unless otherwise indicated, the directional terms described herein are generally in accordance with conventional directions as understood by those skilled in the art.

The terms "first," "second," and the like as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

Fig. 1 to 7 show, by way of example, a switchgear 1 of the invention, comprising a cabinet 2, a hand truck 3 and an interlocking mechanism 4. The switching device 1 may be, for example, a high-voltage switching device. The cabinet 2 includes a cabinet body 21 defining an internal space and an opening communicating with the internal space, and a cabinet door 22 movable to open or close the opening. Electrical components, such as stationary contacts, are accommodated in the inner space of the cabinet 2. The cabinet door 22 is connected to the cabinet 21, for example, in a pivotable, translatable or detachable manner. When the cabinet door 22 is opened, the hand truck 3 can be moved into or out of the interior space of the cabinet 2. In one embodiment, tracks may be provided within the cabinet 21 and the hand truck 3 moved along the tracks by means of an external actuating and/or transmission mechanism to enter and exit the cabinet 21. The hand truck 3 has an off position, a testing position and an operating position with respect to the cabinet 21. When the handcart 3 is in the disconnection position, the handcart 3 leaves the cabinet body 21, and no connection exists between the handcart 3 and the electric elements in the cabinet body 21, so that the handcart 3 can be overhauled. Under the test position, the handcart 3 is in the inner space of the cabinet body 21, a primary electric element on the handcart 3 is not connected with an electric element in the cabinet body 21, and a secondary plug on the handcart 3 can be inserted into a secondary socket 5 in the cabinet body 21. In the working position, the handcart 3 is further pushed into the cabinet 21 relative to the test position, and a primary electrical element carried on the handcart 3, such as a moving contact, is connected with a fixed contact in the cabinet 21 in place, so that a primary loop between the handcart 3 and the cabinet 21 is conducted, and meanwhile, a secondary loop is kept conducted. In the technical solution shown in the present invention, the primary circuit and the secondary circuit of the switch device 1 are the same as those of the switch device in the prior art, and are not described in detail herein.

In one embodiment, the secondary plug 31 may be coupled to the outside of the hand truck 3 via a flexible connection so that the secondary plug 31 may have a certain displacement stroke with respect to the hand truck 3.

As shown in fig. 1 to 7, in the illustrated embodiment, the interlocking mechanism 4 includes a holder 41, an interlocking piece 42, and a stopper 43. The holder 41 is fixedly mounted on an inner side surface of the cabinet 21, for example, a top surface of the cabinet 21. The fixing means may be, for example, welding, bolting, gluing, etc. In one embodiment, the support 41 may include a first seat 411 fixed to an inner side of the cabinet 21 and a second seat 412 connected to the first seat 411 at an angle (e.g., vertically). An accommodation space is defined between the first seat 411 and the second seat 412. The support 41 may be integrally formed from sheet metal, for example by bending, punching, etc., to control cost and simplify manufacturing difficulties.

The interlocking member 42 is pivotally mounted to the support 41 by means of a pivot shaft 426, such as may be mounted to the second housing 412. In the illustrated embodiment, the interlock 42 includes a first plate segment 422 and a second plate segment 423, wherein the first plate segment 422 is pivotally connected to the support 41 and the second plate segment 423 is angularly connected to the first plate segment 422. The end of the first plate segment 422 distal to the second plate segment 423 defines a first end 424 of the interlocking member 42 facing the cabinet door 22, while the end of the second plate segment 423 distal to the first plate segment 422 defines a second end 425 of the interlocking member 42 facing the secondary receptacle 5. The first and second ends 424 and 425 are located on opposite sides of the pivot axis of the interlocking member 42. Interlocking member 42 may be integrally formed from sheet metal, such as by bending, punching, etc., to control cost and simplify manufacturing.

The stop 43 is slidably mounted on the support 41 and can be actuated by the interlocking member 42 to perform a predetermined function. In one embodiment, the support 41 has a vertical slot and the stop 43 defines an aperture, and the pin is disposed through the vertical slot and the aperture and is slidable along the vertical slot, whereby the stop 43 is slidable up and down the vertical slot. The vertical groove may be formed, for example, on the first seat 411 of the stand 41, and the stopper 43 is received in the receiving space of the stand 41 defined by the first seat 411 and the second seat 412. The stop member 43 may be integrally formed from sheet metal, such as by bending, punching, etc., to control cost and simplify manufacturing difficulties.

In the illustrated embodiment, the relationship between the stop 43 and the interlock 42 is configured such that upward movement of the stop 43 along the vertical slot is caused by pivotal movement of the interlock 42. For example, as shown in fig. 3-6, the rotational movement of the interlocking member 42 about the pivot axis 426 causes the second end 425 thereof to engage (or abut) the underside of a portion of the stop 43, and the second end 425, in response to the rotational movement, pushes or urges the stop 43 to move up the vertical slot.

The operation principle of the interlocking mechanism 4 in the switching device 1 according to the present invention will be described in detail with reference to fig. 1 to 7.

As shown in fig. 1 and 2, the hand truck 3 is not shown in the figures because it is in the off position. Fig. 1 and 2 show the interlocking mechanism 4 in a rest position. The rest posture may also be referred to as an initial posture of the interlock mechanism 4 in which the interlock mechanism 4 is not in contact with the hand truck 3 and the secondary plug 31. Due to the gravity, the second end 425 of the locking member 42 naturally droops and the first end 424 tilts accordingly, so that the first end 424 is kept away from the cabinet door 22, for example, from the protrusion 221 provided on the inner side of the cabinet door 22, to allow the cabinet door 22 to be closed. To stabilize the resting position, the pivot axis 426 may be offset from the middle of the interlocking member 42 and disposed proximate the first end 424. In order to accurately control the deflection angle of the interlocking member 42 around the pivot axis 426 in the resting posture so as to stably realize the interlocking effect of the subsequent interlocking mechanism 4 with the handcart 3 and the secondary plug 31, a limiting member 413 is provided on the support 41, for example, the second base 412. In the rest position, the upper side surface of the first end 424 of the interlocking member 42 abuts against the stopper 413 to control the deflection angle of the interlocking member 42 about the pivot axis 426. In an embodiment not shown, the limiting member 413 may be replaced with an arc-shaped limiting groove, and a pin inserted into the limiting groove is provided on the interlocking member 42. The control of the deflection angle of the interlocking member 42 can also be realized by the radian design of the limiting groove.

In the rest position, the interlocking member 42 does not contact the stopper 43 or drive the stopper 43 to move, and the stopper 43 naturally falls under the lower end of the vertical groove by gravity. Here, a portion, e.g. the lower end, of the stop 43 extends to a position sufficient to interfere with the hand truck 3 being propelled into the cabinet, in preparation for forming a stop engagement with the hand truck 3 in the direction of propulsion.

As shown in fig. 3 and 4, the hand truck 3 is pushed into the cabinet 21 until the test position is reached. Fig. 3 and 4 show the posture of the interlock mechanism 4 in a state where the hand truck 3 is in the trial position and the secondary plug 31 is not yet connected to the secondary receptacle 5, i.e., the interlock posture. In the interlocked position, the cabinet door 22 is not allowed to close and the hand truck 3 is not allowed to advance further.

Specifically, during the pushing of the hand truck 3 into the cabinet 21 to the testing position, the top of the hand truck 3 contacts the interlocking member 42, for example, the first plate segment 422 of the interlocking member 42, and the interlocking member 42 is rotated around the pivot shaft 426 by friction force, so that the first end 424 and the second end 425 of the interlocking member 42 rotate synchronously. Until the hand truck 3 stops in the test position, the first end 424 of the interlocking member 42 is aligned with the cabinet door 22, for example, with the protrusion 221 on the inner side of the cabinet door 22, and the cabinet door 22 is prevented from closing. Meanwhile, the second end 425 of the interlocking member 42 approaches the secondary socket 5 during the rotation, and the distance between the secondary socket 5 and the second end 425 of the interlocking member 42 is small enough to interfere with the insertion of the secondary plug 31 into the secondary socket 5. In one embodiment, the sufficiently small pitch is designed to be smaller than the outer dimensions of the secondary plug 31.

In the interlocking posture, the interlocking piece 42 is still not in contact with the stopper 43, or is only in contact with the stopper 43 and is insufficient to move the stopper 43 against the gravity, and therefore, the stopper 43 is dropped on the lower end of the vertical groove by the gravity. Here, a part of the stop 43, for example the lower end, forms an interference with the hand truck 3 in the advancing direction, and the hand truck 3 cannot be advanced further into the operating position. Therefore, when the handcart 3 reaches the test position and the secondary plug 31 and the secondary socket 5 are not yet engaged, the interlocking mechanism 4, the handcart 3 and the cabinet door 22 form an interlocking effect, the handcart 3 which is caused by misoperation is prevented from being pushed to the working position or the cabinet door 22 is closed, and the safety performance of the switch device 1 is greatly improved. And the interlocking effect is visual, so that an operator can immediately perceive the interlocking effect, and the possibility of misoperation is avoided.

In one embodiment, the rolling members 421 may be provided on the interlocking member 42, for example, the first plate segment 422 of the interlocking member 42, the rolling members 421 are pivotably mounted on the interlocking member 42 by means of pivot shafts, and the outer circumferences of the rolling members 421 are tangential to the top surface of the hand truck 3. The rolling friction formed between the rolling members 421 and the hand truck 3 may be effective to reduce wear on the hand truck 3 during contact between the hand truck 3 and the interlock 42.

As shown in fig. 5 and 6, here the hand truck 3 is in the testing position and the secondary plug 31 is engaged to the secondary socket 5. The interlock mechanism 4 is now in the avoidance position. In the escape position, the cabinet door 22 is allowed to close and the hand truck 3 is allowed to advance further into the cabinet.

Specifically, during the process of inserting the secondary plug 31 into the secondary receptacle 5, the secondary plug 31 must move the second end 425 of the interlocking member 42 away to achieve continuity of the secondary circuit, since the spacing between the second end 425 of the interlocking member 42 and the secondary receptacle 5 is insufficient to accommodate the lower secondary plug 31. The movement of the secondary plug 31 away from the second end 425 of the interlocking member 42 causes the first end 424 of the interlocking member 42 to move synchronously and to open the door 22, for example, to open the protrusion 221 of the door 22, so that the door 22 can be closed. At the same time, movement of the second end 425 of the interlock member 42 also drives the stop 43 out of the hand truck 3 so that the hand truck 3 can continue to advance to the operating position.

In the illustrated embodiment, the secondary plug 31 is enabled to be inserted into the secondary receptacle 5 by jacking or lifting the second end 425 of the interlock member 42. The interlocking member 42 moves up along a vertical slot of the support 41, for example, on the first seat 411, by lifting or raising the stopper 43, to avoid the hand truck 3. When the secondary plug 31 has completed the insertion with the secondary receptacle 5, the secondary plug 31 also functions to support the second end 425 of the interlocking member 42, so that the interlocking member 42 together with the stopper 43 is held in position in the escape posture.

As shown in fig. 7, after interlock mechanism 4 is in the evasive position, hand truck 3 may continue to be propelled into the cabinet to the operating position.

Although the configuration and the operation principle of the interlocking mechanism 4 in the switchgear 1 of the present invention have been described above by way of specific examples, those skilled in the art will understand that there may be many variations of the interlocking mechanism 4 and their combinations with each other according to the operation principle described above.

For example, in one embodiment, not shown, the interlocking member is linearly slidably connected to the support and has opposite first and second ends, wherein the first end faces the cabinet door and the second end faces the secondary receptacle. The support may be provided with a slide slot to limit the sliding of the interlocking member. And in the standing posture, the interlocking piece is in a position which enables the first end of the interlocking piece to be matched with the door closing stop. The pushing of the cart to the testing position drives the interlocking member to slide in a direction away from the door, but still ensures that the second end of the interlocking member can form a door closing stop with the door, and the distance between the second end of the interlocking member and the secondary socket is reduced enough to prevent the secondary plug from being inserted into the secondary socket. The stop is here in a position to form an interference with the hand truck in the direction of propulsion. Thereby achieving the interlocking posture of the interlocking mechanism. The avoidance attitude is achieved by having the secondary plug push against the second end of the interlock member causing the interlock member to slide upwardly while the interlock member pushes the stop upwardly. The sliding movement of the interlocking member may be multi-sectional, with each section of the sliding movement being at an angle to the other.

In a further embodiment, which is not shown, the locking part and the stop can be two parts of a component, or the stop can be connected to the locking part, which is designed such that the following conditions are met: under the interlocking posture, the first end of the interlocking piece and the cabinet door form a door closing stopping matching, the distance between the second end and the secondary socket is small enough to prevent the secondary plug from being inserted into the secondary socket, and meanwhile, the stopping piece is located at a position capable of forming a stopping matching with the handcart along the pushing direction. And under the avoiding posture, the second end of the interlocking piece is pushed away by the secondary plug and is supported by the secondary plug, the first end avoids the cabinet door, and the stop piece moves to the position of avoiding the handcart.

In a further embodiment, not shown, a transmission structure may be provided between the hand truck and the interlock.

It should be understood that although the description is in terms of various embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and those skilled in the art will recognize that the embodiments described herein may be combined as suitable to form other embodiments, as will be appreciated by those skilled in the art.

The above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations that may be made by those skilled in the art without departing from the spirit and principles of the invention should be considered within the scope of the invention.

Claims (10)

1. An interlock mechanism for a switching device, wherein the switching device (1) comprises:

a cabinet (2) having a cabinet body (21) and a cabinet door (22) capable of opening and closing the cabinet body (21), wherein a secondary socket (5) is provided in the cabinet body (21);

a hand truck (3) movable into and out of said cabinet (21) and provided with a secondary plug (31) detachably engageable with said secondary socket (5), wherein said hand truck (3) has a testing position and a working position within said cabinet (21);

characterized in that said interlocking mechanism (4) comprises:

a support (41) provided inside the cabinet (21);

an interlocking member (42) movably connected to the seat (41) and having a first end (424) directed towards the cabinet door (22) and a second end (425) directed towards the secondary socket (5);

a stop (43) which is coupled to the interlocking member (42) in a following manner;

wherein the interlocking mechanism (4) has an interlocking posture in a state that the handcart (3) is at a test position and the secondary socket (5) is not jointed with the secondary plug (31) and a dodging posture in a state that the handcart (3) is at the test position and the secondary socket (5) is jointed with the secondary plug (31);

in the interlocking posture, a first end (424) of the interlocking piece (42) forms a door closing stopping fit with the cabinet door (22), and the stopping piece (43) forms a stopping fit with the handcart (3) along the direction of entering the cabinet body (21);

under the avoidance posture, a first end (424) of the interlocking piece (42) gives way to the cabinet door (22), and the stop piece (43) gives way to the handcart (3) in response to the movement of the interlocking piece (42).

2. Interlocking mechanism according to claim 1, characterized in that the interlocking member (42) is arranged such that during movement of the hand truck (3) in the direction into the cabinet body (21) to the test position, the interlocking member (42) is in contact with the hand truck (3) and is driven by the hand truck (3) such that the first end (424) forms a door closing stop engagement with the cabinet door (22).

3. Interlocking mechanism according to claim 2, characterized in that the interlocking member (42) is provided with pivotable rolling members (421), the rolling members (421) forming a rolling friction fit with the hand truck (3) during movement of the hand truck (3) in a direction into the cabinet (21) to the testing position.

4. Interlocking mechanism according to claim 1, characterized in that the interlocking piece (42) is arranged such that:

in the interlocked position, the second end (425) approaches the secondary receptacle (5) at a distance sufficient to interfere with engagement of the secondary plug (31) to the secondary receptacle (5);

during the approach and engagement of the secondary plug (31) with the secondary socket (5), the second end (425) is driven by the secondary plug (31) to clear the first end (424) from the cabinet door (22).

5. Interlocking mechanism according to claim 1, characterized in that one of said support (41) and said stop (43) has a vertical slot and the other has an opening, a pin passing in said opening and vertical slot, wherein, during the movement of said interlocking member (42) to its first end (424) to clear said cabinet door (22), said stop (43) is pushed by said interlocking member (42) and moves up along said vertical slot to clear said hand truck (3), while during the movement of said interlocking member (42) to its first end (424) to form a closing stop cooperation with said cabinet door (22), said stop (43) is located at the lower end of said vertical slot and forms a stop cooperation with said hand truck (3).

6. Interlocking mechanism according to claim 1, characterized in that the interlocking member (42) comprises:

a first plate segment (422) pivotally connected to the support (41);

a second plate segment (423) angularly connected to the first plate segment (422);

wherein an end of the first plate segment (422) distal to the second plate segment (423) defines the first end (424) of the interlock (42), and an end of the second plate segment (423) distal to the first plate segment (422) defines the second end (425) of the interlock (42).

7. Interlocking mechanism according to any one of claims 1 to 6, characterized in that the interlocking mechanism (4) also has a rest position in which the first end (424) of the interlocking member (42) gives way to the cabinet door (22) in the state in which the hand truck (3) has not entered the test position.

8. Interlocking mechanism according to claim 7, characterized in that the support (41) is provided with a stop (413), the interlocking member (42) resting against the stop (413) under the action of gravity in the rest position.

9. A switching device, comprising:

a cabinet (2) having a cabinet body (21) and a cabinet door (22) capable of opening and closing the cabinet body (21), wherein a secondary socket (5) is provided in the cabinet body (21);

a hand truck (3) movable into and out of said cabinet (21) and provided with a secondary plug (31) detachably engageable with said secondary socket (5), wherein said hand truck (3) has a testing position and a working position within said cabinet (21);

characterized in that the switching device (1) further comprises an interlocking mechanism (4) according to any one of claims 1 to 8.

10. The switching device, as set forth in claim 9, characterized in that the cabinet door (22) has a projection (221) extending towards the inside of the cabinet (2) for forming a closing stop engagement with the first end (424) of the interlocking member (42).

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