CN220306828U - Drawer interlocking device and low-voltage switch cabinet - Google Patents

Abstract

Embodiments provide a drawer interlock and a low voltage switchgear. The drawer interlock includes: a driving member connected to a knob of the low voltage switchgear, the knob being rotatable between an on, off and unlocked position; the support plate is arranged in the low-voltage switch cabinet in a sliding manner along the inserting and pulling direction of the drawer, and is provided with a first slotted hole; a guide fixed to the support plate; a sliding member provided on the guide member and capable of sliding with respect to the guide member under the driving of the driving member; the transmission piece comprises a main body part, a first clamping head and a second clamping head, the main body part is rotationally connected to the supporting plate, the first clamping head penetrates through the first slotted hole, the second clamping head is connected to the sliding piece, the first clamping head is in a first position under the condition that the knob is in the on and off positions, and the first clamping head is in a second position under the condition that the knob is in the unlocking position; and the limiting piece is fixed in the low-voltage switch cabinet, and is clamped with the limiting piece to prevent the supporting plate from sliding under the condition that the first clamping head is positioned at the first position.

Description

Drawer interlocking device and low-voltage switch cabinet

Technical Field

Embodiments of the present disclosure relate generally to the field of electrical equipment, and more particularly, to a drawer interlock for a low-voltage switchgear and a low-voltage switchgear including the same.

Background

Low-voltage switch cabinets are commonly used in power plants, substations, communities, petrochemical industry, textile applications, etc., to distribute and control power systems in such applications. The drawer of the low-voltage switch cabinet needs to be matched with a drawer interlocking device to be used, so that the drawer is prevented from being pulled out of the switch cabinet in the working process of the low-voltage switch cabinet. However, the conventional drawer interlocking device has a large size and a large number of parts, and an unlocking button of the drawer needs to be configured in addition to a switch knob of the low-voltage switch cabinet to be matched with the unlocking button to unlock and draw out the drawer. Therefore, the conventional drawer interlocking device is not suitable for a low-voltage switch cabinet with a small size.

Disclosure of Invention

It is an object of the present disclosure to provide a drawer interlock for a low voltage switchgear and a low voltage switchgear including the same, to at least partially solve the above-mentioned problems.

In a first aspect of the present disclosure, a drawer interlock for a low voltage switchgear is provided. The drawer interlocking device includes: a driving part connected to a knob of the low voltage switchgear, the knob being rotatable in a predetermined direction between an on position, an off position, and an unlock position; the support plate is slidably arranged in the low-voltage switch cabinet along the inserting and pulling direction of the drawer and is provided with a first slotted hole; a guide fixed to a first side of the support plate; a slider provided on the guide and capable of sliding in a sliding direction with respect to the guide under the drive of the driver; a transmission member including a main body portion rotatably connected to a first side of the support plate, a first chuck provided at one end of the main body portion and passing through the first slot, and a second chuck provided at the other end of the main body portion and connected to the slider, wherein the first chuck is in a first position with respect to the first slot with the knob in the on position and the off position, and the first chuck is in a second position with respect to the first slot with the knob in the unlocked position; and the limiting piece is fixed in the low-voltage switch cabinet adjacent to the second side of the supporting plate, and the first clamping head is clamped with the limiting piece to prevent the supporting plate from sliding under the condition that the first clamping head is positioned at the first position.

According to the embodiment of the disclosure, the sliding piece can be driven to move through rotation of the knob, and then the transmission piece is driven to be clamped to the limiting piece or separated from the limiting piece, so that the drawer can be switched between the locking state and the unlocking state, and compared with a traditional mode that the switch knob is matched with the unlocking button to unlock the drawer, the space occupied by the drawer interlocking device by the drawer is reduced, and the operation steps of unlocking the drawer by the drawer interlocking device are simplified.

In some embodiments, the driving member includes a switch extension lever connected to the knob and rotatable in the predetermined direction by the driving of the knob, and a driving piece fixed to the switch extension lever and rotatable in the predetermined direction by the driving of the switch extension lever. In such an embodiment, the switch extension lever is used in conjunction with the driving piece to realize the switch driving of the drawer, so that the force applied to the knob can be reliably transmitted with a simple structure.

In some embodiments, a protrusion is provided on the driving plate, wherein the protrusion drives the slider to slide in the sliding direction with respect to the guide in case the knob is switched from the on position or the off position to the unlocking position. In such an embodiment, by driving the slider to slide with the projection, the force on the driving plate can be reliably transmitted to the slider and the rotational movement of the driving plate can be converted into the translational movement of the slider.

In some embodiments, the sliding member is provided with a positioning member and a second slot, wherein the positioning member is sleeved with a spring along the sliding direction, one end of the spring is abutted to the sliding member, the other end of the spring is abutted to the guiding member, and the protruding part can extend into and abut against the second slot to drive the sliding member to move along the sliding direction when the knob is switched from the on position or the off position to the unlocking position. In such an embodiment, when no force is applied to the knob, the spring is sleeved in the sliding member, so that the spring can apply an elastic force to the sliding member and drive the sliding member to slide along the sliding direction, and then drive the driving piece and the switch extension rod to rotate until the protruding portion is separated from the second slot hole, thereby realizing the conversion from the unlocking position to the closing position of the knob. In some embodiments, the sliding member is provided with a clamping groove, and the second clamping head is connected to the clamping groove and can move under the driving of the clamping groove so as to enable the transmission member to rotate. In such an embodiment, by means of the engagement groove on the slider being connected to the second chuck on the transmission member, the force on the slider can be reliably transmitted to the second chuck and the translational movement of the slider can be converted into a rotational movement of the transmission member. In some embodiments, a pin is provided on a first side of the support plate, the body portion of the transmission being rotatably connected to the pin. In such an embodiment, the pin can reliably connect the driving member and the support plate and provide a stable rotation center for the driving member, thereby improving the driving stability of the driving member.

In some embodiments, the limiting member is provided with at least one limiting notch, and the at least one limiting notch is used for being clamped with the first chuck when the first chuck is located at the first position. In such an embodiment, the drawer can be reliably locked in the low-voltage switchgear by engaging the first chuck with the limit notch.

In some embodiments, the limiting member is provided with a first limiting gap, a second limiting gap and a third limiting gap, the first limiting gap can be clamped with the first clamping head when the drawer is not pulled out, the second limiting gap can be clamped with the first clamping head when the drawer is pulled out to a middle position, and the third limiting gap can be clamped with the first clamping head when the drawer is further pulled out relative to the middle position. In such an embodiment, the drawer can be reliably locked in different positions relative to the low-voltage switchgear by engaging the first chuck with the first limiting notch, the second limiting notch, and the third limiting notch.

In some embodiments, under the condition that the first limiting notch is in clamping fit with the first clamping head, the drawer is in a normal working position; under the condition that the second limiting notch is matched with the first clamping head in a clamping way, the drawer is positioned at a testing position; under the condition that the third limiting notch is matched with the first clamping head in a clamping way, the drawer is in the extraction position. In such an embodiment, the drawer can be prevented from being erroneously pulled out in the case where the drawer is locked in the normal operation position, avoiding the safety problem; under the condition that the drawer is at the testing position, the drawer can be conveniently tested; and in the case that the drawer is in the drawn-out position, the electric components in the drawer can be conveniently operated.

In some embodiments, the guide member is provided with a pair of guide grooves, and the slider is inserted into the pair of guide grooves and is slidable with respect to the pair of guide grooves. In such an embodiment, the slider can be made to slide smoothly in the sliding direction by employing a manner in which the slider is pierced in the paired guide grooves.

In a second aspect of the present disclosure, there is provided a low voltage switchgear comprising a drawer interlock according to the first aspect of the present disclosure.

It should be understood that what is described in this section of content is not intended to limit key features or essential features of the embodiments of the present disclosure nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

The above and other features, advantages and aspects of embodiments of the present disclosure will become more apparent by reference to the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, wherein like or similar reference numerals denote like or similar elements, in which:

FIG. 1 illustrates a schematic structural view of a knob according to one embodiment of the present disclosure;

FIG. 2 illustrates a schematic view of a drawer interlock in an unlocked state according to one embodiment of the present disclosure;

FIG. 3 illustrates a schematic view of a drawer interlock in an on state according to one embodiment of the present disclosure;

FIG. 4 illustrates a schematic view of a drawer interlock in an off state according to one embodiment of the present disclosure;

FIG. 5 illustrates a schematic structural view of a guide according to one embodiment of the present disclosure;

FIGS. 6 and 7 illustrate schematic structural views of a slider from different perspectives according to one embodiment of the present disclosure;

FIG. 8 illustrates a partial cross-sectional schematic view of a drawer interlock in an unlocked state from a top view, according to one embodiment of the present disclosure;

FIG. 9 illustrates a partial cross-sectional schematic view of a drawer interlock in an on-state or an off-state from a top view in accordance with one embodiment of the present disclosure;

FIG. 10 illustrates a partial enlarged schematic view of a drawer interlock in an unlocked state according to one embodiment of the present disclosure; and

fig. 11 illustrates a schematic structural view of a stopper according to an embodiment of the present disclosure.

Reference numerals illustrate:

1 drawer interlocking device 2 knob

11 drive member 12 projection

111 switch extension rod 112 guide piece

13 support plate 14 guide

15 slide 16 transmission

131 first side 132 second side

133 first slot 134 pin

171 first limit notch 172 second limit notch

173 third limit notch 141 guide groove

151 locating piece 152 second notch

161 first chuck 162 second chuck

17 limit 153 spring

154 catch 163 body portion

21 on position 22 off position

23 unlocking position X predetermined direction

Y sliding direction Z inserting and pulling direction

142 mounting portion

Detailed Description

Preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present disclosure are illustrated in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The term "comprising" and variations thereof as used herein means open ended, i.e., "including but not limited to. The term "or" means "and/or" unless specifically stated otherwise. The term "based on" means "based at least in part on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment. The term "another embodiment" means "at least one additional embodiment". The terms "first," "second," and the like, may refer to different or the same object.

As described above, the conventional drawer interlock is large in size, large in number of parts, and complicated in unlocking operation, and is not suitable for a low-voltage switchgear having a small volume. Embodiments of the present disclosure provide a drawer interlock for a low-voltage switchgear, in which a slider is driven to move by rotation of a knob, and then a transmission member is driven to be clamped to or separated from a stopper, thereby achieving switching of a drawer between a locked state and an unlocked state. Hereinafter, the principles of the present disclosure will be described with reference to fig. 1 to 11.

Fig. 1 illustrates a schematic structural view of a knob 2 according to an embodiment of the present disclosure, and fig. 2 to 4 illustrate schematic structural views of a drawer interlock 1 according to an embodiment of the present disclosure in an unlocked state, an on state, and an off state, respectively. The knob 2 is rotatable between an on position 21, an off position 22 and an unlocked position 23. When the knob 2 is turned to the on position 21, the drawer interlock 1 is in an on state, in which the drawer can be powered on and in a locked state, so that it cannot be pulled out of the low-voltage switchgear; when the knob 2 is turned to the off position 22, the drawer interlocking device 1 is in an off state, and at the moment, the drawer is turned off and is in a locking state, so that the drawer cannot be pulled out of the low-voltage switch cabinet; when the knob 2 is turned to the unlocking position 23, the drawer interlocking device 1 is in an unlocking state, at this time, the drawer is unlocked and can be pulled out from the low-voltage switch cabinet, the knob 2 needs to be maintained at the unlocking position 23 in the whole process of pulling out the drawer, and at this time, the knob 2 needs to be continuously applied with a sufficient force.

As shown in fig. 1 to 4, the drawer interlock 1 described herein generally includes a driving member 11, a support plate 13, a guide member 14, a sliding member 15, a transmission member 16, and a stopper member 17. The driver 11 is connected to a knob 2 of the low-voltage switchgear, the knob 2 being rotatable between an on position 21, an off position 22 and an unlocked position 23 and driving the driver 11 in a predetermined direction X. The support plate 13 is slidably disposed in the low voltage switchgear in the insertion and extraction direction Z of the drawer to support the guide 14, the slider 15, the transmission member 16, and other elements of the drawer, and the support plate 13 is provided with a first slot 133. The guide 14 is fixed to the first side 131 of the support plate 13. The slider 15 is provided to penetrate the guide 14 and is capable of sliding in the sliding direction Y relative to the guide 14 by the drive of the driver 11. The transmission member 16 includes a body portion 163, a first chuck 161 and a second chuck 162, the body portion 163 being rotatably coupled to the first side 131 of the support plate 13, the first chuck 161 being disposed at one end of the body portion 163 and passing through the first slot 133 of the support plate 13, the second chuck 162 being disposed at the other end of the body portion 163 and being coupled to the sliding member 15 to convert translational movement of the sliding member 15 into rotational movement of the transmission member 16. The limiting member 17 is fixed in the low voltage switchgear adjacent the second side 132 of the support plate 13, and the limiting member 17 can be clamped with the first clamping head 161 on the transmission member 16 to prevent the support plate 13 from sliding.

In one embodiment, as shown in fig. 1 to 4, the driving member 11 includes a switch extension lever 111 and a driving piece 112, the switch extension lever 111 is connected to the knob 2 and is rotatable in a predetermined direction X by the driving of the knob 2, and the driving piece 112 is fixed to the switch extension lever 111 and is rotatable in the predetermined direction X by the driving of the switch extension lever 111. The driving piece 112 is provided with a protruding portion 12, and in the case where the knob 2 is switched from the on position 21 or the off position 22 to the unlock position 23, the switch extension lever 111 is driven by the force applied to the knob 2 and rotates in the predetermined direction X to drive the protruding portion 12 on the driving piece 112 to rotate in the predetermined direction X to drive the slider 15 to slide in the sliding direction Y with respect to the guide 14; in the case where the knob 2 is switched from the off position 22 to the on position 21, the switch extension lever 111 is driven by the force exerted on the knob 2 and simultaneously drives the driving piece 112 to rotate in the predetermined direction X until the knob 2 rotates to the on position 21, during which the driving piece 112 and the protruding portion 12 are not in contact with the slider 15 and the slider 15 remains relatively stationary with the guide 14. In some embodiments, a square bar having a square cross-sectional shape may be used as the switch extension bar 111, and a sheet having a circular outline other than the protruding portion may be used as the driving piece and an extending portion extending away from the center of the circle and having a ox horn shape may be used as the protruding portion. Other types of switch extension bars, drive tabs, and tabs, as would occur to one of ordinary skill in the art based on the teachings presented in this disclosure, accomplish the above functions, which fall within the scope of this disclosure.

Fig. 5 shows a schematic structural view of the guide 14 according to one embodiment of the present disclosure. In one embodiment, as shown in fig. 5, the guide 14 is provided with a pair of guide grooves 141 and a pair of mounting portions 142, the guide grooves 141 being distributed on both sides of the guide 14, and the pair of mounting portions 142 being provided at the bottom of the guide 14. In one embodiment, as shown in fig. 2 to 5, the guide 14 is fixed to the first side 131 of the support plate 13 by the mounting portion 142, the slider 15 is penetrated into the pair of guide grooves 141, and the slider 15 is capable of abutting against the pair of guide grooves 141 and sliding in the sliding direction Y with respect to the guide 14. In some embodiments, the guide 141 may be secured to the support plate 13 using bolts at the mounting portion 142, it being understood that other securing means may occur to those of ordinary skill in the art based on the teachings provided herein and such implementations fall within the scope of the present disclosure.

Fig. 6 and 7 show schematic structural views of a slider 15 according to one embodiment of the present disclosure from different perspectives. In one embodiment, as shown in fig. 6 and 7, the slider 15 includes a second slot 152, a positioning member 151, and a clamping groove 154. The second slot 152 is disposed at the top of the sliding member 15, the positioning member 151 is disposed at the middle of the sliding member 15, and the clamping groove 154 is disposed at the bottom of the sliding member 15. In one embodiment, as shown in fig. 5 to 7, the edge shape of the slider 15 corresponds to the edge shape of the guide groove 141 and the edge size of the slider 15 is slightly smaller than the edge size of the guide groove 141 to ensure that the slider 15 can be inserted into the guide groove 141 and smoothly slide relative to the guide 14.

In one embodiment, as shown in fig. 2 to 4, in the case where the drawer interlock 1 is switched from the on state or the off state to the unlocked state, the protrusion 12 can extend into and abut against the second slot 152 to continuously apply a pushing force to the second slot 152 to drive the slider 15 to move in the sliding direction Y.

Fig. 8 and 9 show partial cross-sectional schematic views in top view of the drawer interlock 1 in an unlocked state and an on or off state, respectively, according to one embodiment of the present disclosure. In one embodiment, as shown in fig. 8 and 9, the positioning member 151 is provided with a spring 153 sleeved thereon in the sliding direction Y, one end of the spring 153 abutting against the sliding member 15 and the other end abutting against the guide member 14. In the case where the drawer interlock 1 is switched from the on state or the off state to the unlocked state, the pushing force continuously applied by the protruding portion 12 on the slider 15 pushes the slider 15 to move in the sliding direction Y against the elastic force applied to the slider 15 by the spring 153, and when the slider 15 moves to the position shown in fig. 8, the drawer interlock 1 enters the unlocked state; as shown in fig. 8, when the drawer interlock 1 is in the unlocked state, the spring 153 is compressed by a certain amount of deformation and continuously applies elastic force to the slider 15 and the guide 14. In the case where the drawer interlock 1 is switched from the unlocked state to the off state, the pushing force is not continuously applied to the slider 15 (i.e., the knob 2 is not continuously applied with the force), the elastic force applied to the slider 15 by the spring 153 drives the slider 15 to slide in the sliding direction Y until the spring 153 is reset, in which process the second slot 152 on the slider 15 pushes the protrusion 12 on the driving plate 112 to rotate in the predetermined direction X to thereby drive the switch extension lever 111 and the knob 2 connected to the switch extension lever 111 to rotate until the protrusion 12 leaves the second slot 152 and is not in contact with the second slot 152.

Fig. 10 shows an enlarged partial view of the drawer interlock 1 in an unlocked position according to one embodiment of the present disclosure, in which the transmission member 16 includes a body portion 163, a first chuck 161, and a second chuck 162, and the support plate 13 is provided with a first slot 133 and a pin 134, as shown in fig. 10. The body part 163 is rotatably coupled to the pin shaft 134, the first chuck 161 is provided at one end of the body part 163 and passes through the first slot hole 133 of the support plate 13, and the second chuck 162 is provided at the other end of the body part 163 and is coupled to the chuck slot 154 of the slider 15. When the sliding member 15 slides along the sliding direction Y, the sliding member 15 can drive the second chuck 162 to move along an arc track with a certain angle around the pin 134, and at this time, the first chuck 161 moves along an arc track with the same angle and in an opposite direction around the pin 134. It should be understood that any other suitable connection between the transmission member 16 and the support plate 13 may be used and such implementations are within the scope of this disclosure.

As shown in fig. 9, in the case where the drawer interlock device 1 is in the on state and the off state, the first chuck 161 is in the first position with respect to the first slot 133, at which time the drawer is locked in the low-voltage switchgear and is not extractable; as shown in fig. 8, when the drawer interlock device 1 is in the unlocked state, the first chuck 161 is in the second position with respect to the first slot 133, and the drawer can be pulled out of the low-voltage switchgear.

Fig. 11 shows a schematic structural view of the stopper 17 according to one embodiment of the present disclosure. In one embodiment, as shown in fig. 2 and 11, the stop 17 includes a first stop notch 171, a second stop notch 172, and a third stop notch 173. The first limiting notch 171, the second limiting notch 172 and the third limiting notch 173 are disposed at the edge of the limiting member 17 at a certain interval, so as to be clamped with the first clamping head 161 extending from the first slot 133 to prevent the supporting plate 13 from sliding. Under the condition that the first limiting notch 171 is matched with the first clamping head 161 in a clamping way, the drawer is in a normal working position, and at the moment, the drawer is powered on and works normally; under the condition that the second limiting notch 172 is matched with the first clamping head 161 in a clamping way, the drawer is in a testing position, and at the moment, the drawer is powered off and is pulled out to the middle position, so that the drawer can be conveniently tested; when the third limiting notch 173 is engaged with the first chuck 161, the drawer is in the extraction position, and at this time, the drawer is powered off and is further extracted relative to the intermediate position, so that the electrical components in the drawer can be conveniently operated. In other embodiments, different shapes or numbers of limiting indentations may be provided, all falling within the scope of the present disclosure.

The foregoing description of the embodiments of the present disclosure has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the technical improvement in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (11)

1. Drawer interlock (1) for a low voltage switchgear, characterized in that the drawer interlock (1) comprises:

a drive (11) connected to a knob (2) of the low-voltage switchgear, the knob (2) being rotatable in a predetermined direction (X) between an on position (21), an off position (22) and an unlocking position (23);

a support plate (13) slidably disposed in the low-voltage switchgear cabinet along a drawer insertion and extraction direction (Z) and provided with a first slot hole (133);

a guide (14) fixed to a first side (131) of the support plate (13);

a slider (15) provided on the guide (14) and capable of sliding in a sliding direction (Y) relative to the guide (14) under the drive of the driver (11);

-a transmission member (16) comprising a body portion (163), a first chuck (161) and a second chuck (162), the body portion (163) being rotatably connected to a first side (131) of the support plate (13), the first chuck (161) being arranged at one end of the body portion (163) and passing through the first slot (133), the second chuck (162) being arranged at the other end of the body portion (163) and being connected to the slider (15), wherein the first chuck (161) is in a first position with respect to the first slot (133) in case of the knob (2) being in the on position (21) and the off position (22), and the first chuck (161) is in a second position with respect to the first slot (133) in case of the knob (2) being in the off position (23); and

and a limiting member (17) fixed in the low-voltage switch cabinet adjacent to the second side (132) of the support plate (13), wherein the first clamping head (161) is clamped with the limiting member (17) to prevent the support plate (13) from sliding when the first clamping head (161) is in the first position.

2. Drawer interlocking device (1) according to claim 1, characterized in that the drive member (11) comprises a switch extension rod (111) and a drive piece (112), the switch extension rod (111) being connected to the knob (2) and being rotatable in the predetermined direction (X) under the drive of the knob (2), the drive piece (112) being fixed to the switch extension rod (111) and being rotatable in the predetermined direction (X) under the drive of the switch extension rod (111).

3. Drawer interlock (1) according to claim 2, characterized in that the drive tab (112) is provided with a projection (12), wherein the projection (12) drives the slide (15) to slide in the sliding direction (Y) relative to the guide (14) in case the knob (2) is switched from the on position (21) or the off position (22) to the unlocked position (23).

4. A drawer interlock (1) according to claim 3, characterized in that the slide (15) is provided with a positioning element (151) and a second slot (152), wherein the positioning element (151) is provided with a spring (153) in the sliding direction (Y), one end of the spring (153) being against the slide (15) and the other end being against the guide (14), the projection (12) being able to extend into and against the second slot (152) in order to drive the slide (15) to move in the sliding direction (Y) in case the knob (2) is switched from the on position (21) or the off position (22) to the unlocked position (23).

5. Drawer interlocking device (1) according to claim 1, characterized in that the slide (15) is provided with a clamping groove (154), the second clamping head (162) being connected to the clamping groove (154) and being movable under the drive of the clamping groove (154) for rotating the transmission member (16).

6. Drawer interlocking device (1) according to claim 1, characterized in that a pin (134) is provided on a first side (131) of the support plate (13), the main body portion (163) of the transmission member (16) being rotatably connected to the pin (134).

7. Drawer interlocking device (1) according to claim 1, characterized in that the limiting piece (17) is provided with at least one limiting notch for clamping the first clamping head (161) in the case of the first clamping head (161) being in the first position.

8. The drawer interlock (1) of claim 7 wherein the at least one limit notch includes a first limit notch (171), a second limit notch (172), and a third limit notch (173), the first limit notch (171) being capable of being engaged with the first clamp head (161) without the drawer being withdrawn, the second limit notch (172) being capable of being engaged with the first clamp head (161) with the drawer being withdrawn to an intermediate position, the third limit notch (173) being capable of being engaged with the first clamp head (161) with the drawer being further withdrawn relative to the intermediate position.

9. The drawer interlocking device (1) according to claim 8, wherein the drawer is in a normal working position with the first limiting notch (171) in snap fit with the first chuck (161); under the condition that the second limiting notch (172) is matched with the first clamping head (161) in a clamping way, the drawer is positioned at a testing position; under the condition that the third limiting notch (173) is in clamping fit with the first clamping head (161), the drawer is in the extraction position.

10. Drawer interlocking device (1) according to claim 1, characterized in that the guide (14) is provided with a pair of guide grooves (141), the slide (15) being threaded into the pair of guide grooves (141) and being slidable relative to the pair of guide grooves (141).

11. A low-voltage switchgear characterized in that it comprises a drawer interlock (1) according to any one of claims 1 to 10.