A preventive interlocking device for a land-leveling handcart

Abstract

This invention relates to the field of switchgear, and particularly to a preventive interlocking device for a floor switch trolley. It includes a side plate with a front folding plate and an operating hole. A guide rail is fixedly mounted on the side plate, and the guide rail has two through holes. Retractable movable blocks are respectively installed in the two through holes. A sliding plate is vertically slidably connected to the front folding plate. An interlocking assembly is connected between the sliding plate and the two movable blocks, and the interlocking assembly drives the two movable blocks to simultaneously protrude from the two through holes of the guide rail. A mounting plate is fixedly mounted in the side plate, and an operating shaft is rotatably connected to the mounting plate. A main shaft is rotatably mounted relative to the mounting plate next to the operating shaft. A transmission mechanism is connected between the operating shaft and the main shaft, allowing the operating shaft to extend and retract along its axial direction. This invention has high reliability and will not damage the components in the interlocking mechanism.

Description

Technical Field

[0001] This invention relates to the field of switchgear, and in particular to a preventive interlocking device for a floor switch trolley. Background Technology

[0002] To prevent accidents, some switchgear has been equipped with passive forced limit interlocks, which forcibly limit the operation to stop it midway during misoperation. Passive forced limit interlocks cause great damage to the spindle and can easily cause spindle deformation. Some switchgear also use electromagnetic locks and limit switches to protect against accidents using electrical equipment. However, electrical equipment is less reliable than mechanical interlocks. Summary of the Invention

[0003] The purpose of this invention is to provide a preventive interlocking device for ground-operated handcarts, which has good reliability and will not damage the components in the interlocking.

[0004] This invention is achieved through the following technical solution: a preventive interlocking device for a ground-operated handcart, characterized in that: it includes a side plate, a front folding plate on the side plate, an operating hole on the front folding plate, a guide rail extending in the front-rear direction fixedly mounted on the side plate, two through holes (one above and one below) on the guide rail, and retractable movable blocks respectively mounted in the two through holes; a sliding plate is vertically slidably connected to the front folding plate, and an interlocking assembly is also connected between the sliding plate and the two movable blocks; when the sliding plate is in the upward sliding state, the sliding plate blocks the operating hole, and the interlocking assembly drives the two movable blocks to simultaneously protrude out of the two through holes of the guide rail; when the sliding plate is in the downward sliding state, the sliding plate opens the operating hole, and the interlocking assembly drives the two movable blocks to simultaneously retract into the two through holes of the guide rail.

[0005] A mounting plate is fixedly installed in the side plate, and an operating shaft is rotatably connected to the mounting plate. A main shaft is provided next to the operating shaft and is rotatably arranged relative to the mounting plate for controlling the opening and closing of the grounding switch. A transmission mechanism is also connected between the operating shaft and the main shaft for driving the main shaft to rotate during the rotation of the operating shaft.

[0006] The operating shaft can extend and retract along its axial direction. When the rear door is closed, the operating shaft can move closer to the operating hole under the pressure of the rear door. An elastic element for driving the operating shaft to reverse reset is also connected between the operating shaft and the side plate. When the rear door is opened, the operating shaft moves away from the operating hole under the action of the elastic element.

[0007] The above-mentioned grounding switch handcart preventive interlocking device of the present invention adopts an active prevention method, that is, when the grounding switch operation conditions are not met, the operating shaft automatically retracts, so that the operating handle cannot be sleeved on the operating shaft, ensuring that the grounding switch cannot be operated erroneously, or the grounding operating hole cannot be opened due to the obstruction of the sliding plate, so as not to damage any parts of the interlock; moreover, it adopts a mechanical linkage structure, which has high reliability.

[0008] As a further improvement, a stop pin is also fixed on the main shaft, and a limiting part corresponding to the stop pin is also fixed on the slide plate. The stop pin of the main shaft has a limiting state of locking the limiting part and a disengaging state of disengaging from the limiting part during forward and reverse rotation. When the main shaft rotates in one direction and controls the grounding switch to close, the stop pin locks the limiting part to restrict the slide plate from moving upward.

[0009] As a further improvement, the transmission mechanism includes a drive pinion sleeved around the outer circumference of the operating shaft and rotating synchronously with the operating shaft, and a main shaft gear fixedly mounted to the main shaft. The drive pinion meshes with the main shaft gear for transmission. Preferably, the transmission ratio between the drive pinion and the main shaft gear is 1:2. Using a pinion to drive the main gear makes operation easier and less strenuous compared to existing crank arm direct transmission or bevel gear transmission.

[0010] Two one-way needle roller bearings are also sleeved on the outer periphery of the operating shaft. The drive pinion is fixedly sleeved on the outer ring of the two one-way needle roller bearings. The two one-way needle roller bearings are clearance-fitted with the operating shaft, and the two one-way needle roller bearings are installed in opposite directions.

[0011] The design employs two one-way needle roller bearings, one mounted in the forward direction and the other in the reverse direction, to ensure that the operating shaft can drive the grounded operating transmission shaft to rotate together during both forward and reverse rotation. Furthermore, the use of two clearance-fitted one-way needle roller bearings facilitates the extension and retraction of the operating shaft.

[0012] In a preferred embodiment, the operating shaft is rotatably connected to the opposite side plate via two operating shaft sleeves, the operating shaft sleeves are fixedly disposed relative to the mounting plate, the operating shaft is movably inserted through the two operating shaft sleeves, and two one-way needle roller bearings and a drive pinion are located between the two operating shaft sleeves.

[0013] As a further improvement, the operating shaft is also provided with a neck section with a smaller diameter than the other sections. The length of the neck section is longer than the width of a single one-way needle roller bearing. When the rear door is opened, the neck section of the operating shaft is in the relative position of one of the one-way needle roller bearings under the action of the elastic element. When the rear door is closed, the neck section of the operating shaft is disengaged from the relative position of the corresponding one-way needle roller bearing.

[0014] The end of the operating shaft away from the operating hole is also fixedly provided with a radially extending pin. The elastic element is a retraction spring fitted around the outer periphery of the operating shaft. The two ends of the retraction spring press against the pin and a corresponding operating shaft sleeve, respectively.

[0015] As a further improvement, a rear door push plate is slidably connected to the mounting plate. The rear door push plate is slidably arranged parallel to the axis of the mounting plate, with one end of the rear door push plate abutting the end of the operating shaft away from the operating hole, and a rear door top pin fixedly installed at the other end of the rear door push plate. The rear door top pin abuts against the rear door when the rear door is closed. The rear door push plate separates the operating shaft from the rear door, reducing the length of the operating shaft.

[0016] The mounting plate is also provided with a movable hole for facilitating the extension and retraction of the rear door push plate. The rear door push plate passes through the movable hole and is also provided with a vertical folding plate that is perpendicular to it. The vertical folding plate is in contact with one end of the operating shaft.

[0017] The anti-interlocking device for the ground-mounted handcart also includes an operating handle. The operating handle includes a plug that can be inserted into the operating hole and rotate the operating shaft, and a limiting cylinder integrally connected to the plug with an outer diameter larger than the diameter of the operating hole. When the operating shaft is away from the operating hole, the distance between the operating shaft and the operating hole is greater than the length of the plug. The end of the operating shaft near the operating hole is an external hexagonal head, and the plug has an internal hexagonal hole that can engage with and rotate the external hexagonal head.

[0018] As a further improvement, the interlocking assembly includes a control component for controlling the two movable blocks to simultaneously extend or retract into the two through holes, and a linkage mechanism connecting the slide plate and the control component. The linkage mechanism includes a V-shaped crank arm, a transmission pull plate, and a slider. The slider is slidably connected to the guide rail along the extension direction of the guide rail. The transmission pull plate is fixedly set to the slider. The middle part of the V-shaped crank arm is rotatably set relative to the guide rail. The two arms of the V-shaped crank arm are respectively hinged to the slide plate and the transmission pull plate through pins. The control component is controlled by the sliding change of the slider.

[0019] When the slide plate slides down, it drives the slider to slide closer to the front folding plate via the V-shaped crank arm and the transmission pull plate, causing the slider drive control component to drive the two movable blocks to protrude out of the two through holes; when the slide plate slides up, it drives the slider to slide away from the front folding plate via the V-shaped crank arm and the transmission pull plate, causing the slider drive control component to drive the two movable blocks to retract into the two through holes.

[0020] This interlocking assembly controls the extension and retraction of two movable blocks by sliding the slide plate, which in turn drives the slider to slide back and forth via the V-shaped crank arm and the transmission pull plate. Compared with the existing interlocking shaft rotation-driven foot extension and retraction, it occupies less cabinet space, thus making the structure more compact and miniaturized.

[0021] In a preferred embodiment, the control assembly includes an interlock box, a transmission plate, a reset spring, an inner slide plate, and a push plate; the two movable blocks are a locking block and a locking plate bridge, respectively; the interlock box is fixedly mounted on a guide rail, the slider is provided with a straight guide groove extending in the front-to-back direction, and the locking plate bridge is also fixedly provided with two guide pins spaced apart in the front and back, both of which extend in the left-to-right direction and pass through the straight guide groove of the slider, so that the slider can only slide back and forth relative to the interlock box;

[0022] The inner slide plate is fixed to the interlocking box and extends to one end of the two guide pins. The two ends of the guide pins are fixed to the inner slide plate and the interlocking box, respectively. The transmission plate is movably connected to the two guide pins through two holes. The locking plate bridge is also movably connected to the two guide pins through two holes and is located between the transmission plate and the inner slide plate. When the transmission plate is subjected to force and slides along the guiding direction of the guide pins and closer to the inner slide plate, it can push the locking plate bridge to move together, so that the locking plate bridge can protrude from the corresponding through hole of the guide rail. There are two reset springs, which are respectively fitted on the two guide pins, and the two ends of the reset springs press against the inner slide plate and the locking plate bridge, respectively, to provide a reverse reset force.

[0023] The push plate is fixed on the slider. The push plate is provided with a sliding groove for guiding the locking block to extend and retract left and right. The sliding groove includes a wire groove extending in the front-back direction and an inclined groove connected to the wire groove and extending obliquely in the direction away from the locking plate bridge. The locking block is located above the push plate and is fixedly connected to a downward extending pin. The pin is movably inserted in the sliding groove of the push plate and is also fixed to the transmission plate.

[0024] When the slider slides towards the front folding plate, the pin is positioned in the groove of the slide rail in the push plate, causing the locking block and the locking plate bridge to simultaneously protrude from the two through holes of the guide rail. When the slider slides away from the front folding plate, the pin is positioned in the inclined groove of the slide rail in the push plate, causing the locking block and the locking plate bridge to simultaneously retract into the two through holes of the guide rail. The entire control assembly has a simple structure and is easy to manufacture.

[0025] As a preferred embodiment, a reset spring is also connected between the transmission pull plate and the interlock box.

[0026] As a preferred embodiment, the front folding plate is provided with a vertically extending second slide groove, and the slide plate is provided with a handle that is movably inserted into the second slide groove; the front folding plate is also rotatably connected to a padlock plate for connecting with the handle in the upward sliding position, and both the padlock plate and the handle are provided with lock holes. The padlock plate can be locked to the handle when closed, increasing security.

[0027] Compared with previous technologies, the beneficial effects of the present invention are as follows:

[0028] 1. The present invention provides a grounding switch handcart preventive interlocking device, which adopts an active prevention method. That is, when the grounding switch operation conditions are not met, the operating shaft automatically retracts, so that the operating handle cannot be sleeved on the operating shaft, thus ensuring that the grounding switch cannot be misoperated, or the grounding operating hole cannot be opened due to the obstruction of the sliding plate. Therefore, it will not cause damage to any parts of the interlocking; moreover, it adopts a mechanical linkage structure, which has high reliability.

[0029] 2. This invention uses a small gear to drive a large gear, which makes operation easier and less strenuous compared to existing crank arm direct drive or bevel gear drive.

[0030] 3. The interlocking component in this invention adopts a sliding mechanism, which occupies less cabinet space and has a more compact structure. Attached Figure Description

[0031] Figure 1 This is a structural diagram of a specific embodiment of the present invention. Figure 1 ;

[0032] Figure 2 This is a structural diagram of a specific embodiment of the present invention. Figure 2 ;

[0033] Figure 3 This is a schematic diagram of the structure after removing the side plates in a specific embodiment of the present invention. Figure 1 ;

[0034] Figure 4 This is a schematic diagram showing the connection relationship between the rear door and the operating shaft in a specific embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram illustrating the usage state of the present invention with the front door closed, according to a specific embodiment of the invention.

[0036] Figure 6 This is a schematic diagram illustrating the usage state of the present invention with the front door open, according to a specific embodiment of the invention.

[0037] Figure 7 This is a schematic diagram of the structure after removing the side plates in a specific embodiment of the present invention. Figure 2 ;

[0038] Figure 8 This is a schematic diagram of the linkage mechanism and control components in a specific embodiment of the present invention. Figure 1 ;

[0039] Figure 9 This is a schematic diagram of the linkage mechanism and control components in a specific embodiment of the present invention. Figure 2 ;

[0040] Figure 10 This is a schematic diagram illustrating the usage state of the handcart in the locked state of the grounding switch, according to a specific embodiment of the present invention.

[0041] Figure 11 This is a schematic diagram illustrating the handcart in the locked state and the handcart in use, according to a specific embodiment of the present invention.

[0042] Labeling Explanation: 1. Side Plate; 11. Front Folding Plate; 12. Operating Hole; 13. Slide Rail; 2. Guide Rail; 21. Through Hole; 3. Slide Plate; 31. Limiting Part; 32. Handle; 4. Mounting Plate; 41. Movable Hole; 5. Operating Shaft; 51. Neck Reduction Position; 52. External Hexagonal Head; 6. Main Shaft; 61. Stop Pin; 7. Drive Pinion; 8. Main Shaft Gear; 91. One-Way Needle Roller Bearing; 92. One-Way Needle Roller Bearing; 10. Operating Bushing; 101. Pin Shaft; 102. Return Spring; 103. Rear Door Push Plate; 1031. Vertical Folding Plate; 104. Rear Door Top Pin; 105. Operating Handle Handle; 1051, Plug; 1052, Limiting Cylinder; 106, V-shaped Crank Arm; 107, Transmission Pull Plate; 108, Slider; 1081, Linear Guide Groove; 109, Interlocking Box; 20, Transfer Plate; 201, Return Spring; 202, Inner Slide Plate; 203, Push Plate; 2031, Cable Groove; 2032, Inclined Groove; 204, Locking Block; 205, Locking Plate Bridge; 206, Guide Pin; 207, Pin; 208, Return Spring; 209, Padlock Plate; 30, Rear Door; 301, Crank Arm Seat; 302, Handcart; 3021, Ground Knife Locking Plate; 3022, Screw Locking Plate; Detailed Implementation

[0043] The present invention will now be described in detail with reference to the accompanying drawings:

[0044] This embodiment relates to a preventive interlocking device for a ground-operated handcart, such as... Figure 1-11 As shown, the device includes a side plate 1, a front folding plate 11 on the side plate 1, an operation hole 12 on the front folding plate 11, a guide rail 2 extending in the front-rear direction fixedly mounted on the side plate 1, and two through holes 21, one above the other, on the guide rail 2. Retractable movable blocks are respectively installed in the two through holes 21. A sliding plate 3 is vertically slidably connected to the front folding plate 11. An interlocking assembly is also connected between the sliding plate 3 and the two movable blocks. When the sliding plate 3 is in the upward sliding state, the sliding plate 3 blocks the operation hole 12, and the interlocking assembly causes the two movable blocks to simultaneously protrude out of the two through holes 21 of the guide rail 2. When the sliding plate 3 is in the downward sliding state, the sliding plate 3 opens the operation hole 12, and the interlocking assembly causes the two movable blocks to simultaneously retract into the two through holes 21 of the guide rail 2.

[0045] A mounting plate 4 is fixedly installed in the side plate 1. An operating shaft 5 is rotatably connected to the mounting plate 4. A main shaft 6 is provided next to the operating shaft 5, which is rotatably arranged relative to the mounting plate 4 and is used to control the opening and closing of the grounding switch. A transmission mechanism is also connected between the operating shaft 5 and the main shaft 6, which is used to drive the main shaft 6 to rotate during the rotation of the operating shaft 5.

[0046] The operating shaft 5 can extend and retract along its axial direction. When the rear door 30 is closed, the operating shaft 5 can move closer to the operating hole 12 under the pressure of the rear door 30. An elastic element for driving the operating shaft 5 to reverse reset is also connected between the operating shaft 5 and the side plate 1. When the rear door 30 is opened, the operating shaft 5 moves away from the operating hole 12 under the action of the elastic element.

[0047] The grounding switch handcart's preventive interlocking device adopts an active prevention method. That is, if the grounding switch operation conditions are not met, the operating shaft 5 automatically retracts, so that the operating handle 105 cannot be sleeved on the operating shaft 5, ensuring that the grounding switch cannot be misoperated, or the grounding operating hole 12 cannot be opened due to the obstruction of the sliding plate 3. Therefore, it will not cause damage to any parts of the interlocking. Moreover, it adopts a mechanical linkage structure, which has high reliability.

[0048] As a further improvement, such as Figure 3 As shown, a stop pin 61 is also fixed on the main shaft 6, and a limiting part 31 corresponding to the stop pin 61 is also fixed on the slide plate 3. The stop pin 61 of the main shaft 6 has a limiting state of locking the limiting part 31 and a disengaging state of disengaging from the limiting part 31 during forward and reverse rotation. When the main shaft 6 rotates in one direction and controls the grounding switch to close, the stop pin 61 locks the limiting part 31 to restrict the slide plate 3 from moving upward.

[0049] As a further improvement, such as Figure 3-6 As shown, the transmission mechanism includes a drive pinion 7 sleeved around the operating shaft 5 and rotating synchronously with the operating shaft 5, and a main shaft 6 large gear fixedly mounted to the main shaft 6. The drive pinion 7 meshes with the main shaft 6 large gear for transmission. Preferably, the transmission ratio between the drive pinion 7 and the main shaft 6 large gear is 1:2. Using a pinion to drive the large gear makes operation easier and less strenuous compared to existing crank arm direct transmission or bevel gear transmission.

[0050] Two one-way needle roller bearings 92 and 91 are sleeved on the outer periphery of the operating shaft 5. The drive pinion 7 is fixedly sleeved on the outer ring of the two one-way needle roller bearings 92 and 91. The two one-way needle roller bearings 92 and 91 are clearance-fitted with the operating shaft 5, and the two one-way needle roller bearings 92 and 91 are installed in opposite directions. The one-way needle roller bearings are one-way needle roller bearings without inner rings, in which the needle rollers are in direct contact with the operating shaft. During the extension and retraction of the operating shaft, due to the clearance fit, extension and retraction are convenient. Whether the operating shaft rotates forward or backward, the rollers of one of the one-way needle roller bearings will always hold the operating shaft and drive the drive pinion to rotate.

[0051] The design employs two one-way needle roller bearings 92 and 91, one mounted in the forward direction and the other in the reverse direction, so that the operating shaft 5 can drive the grounded operating transmission shaft to rotate together during forward and reverse rotation. Moreover, the use of two clearance-fitted one-way needle roller bearings facilitates the extension and retraction of the operating shaft 5.

[0052] As a preferred method, such as Figure 3-6 As shown, the operating shaft 5 is rotatably connected to the side plate 1 via two operating shaft sleeves 10. The operating shaft sleeves 10 are fixedly set relative to the mounting plate 4. The operating shaft 5 is movably inserted through the two operating shaft sleeves 10. Two one-way needle roller bearings 92 and 91 and the drive pinion 7 are located between the two operating shaft sleeves 10.

[0053] As a further improvement, such as Figure 5-6 As shown, the operating shaft 5 is also provided with a necked section 51 with a diameter smaller than that of other sections. The length of the necked section is greater than the width of a single one-way needle roller bearing. When the rear door 30 is opened, the necked section 51 of the operating shaft 5 is in the relative position of one of the one-way needle roller bearings 91 under the action of the elastic element. When the rear door 30 is closed, the necked section 51 of the operating shaft 5 is disengaged from the relative position of the corresponding one-way needle roller bearing 91.

[0054] The operating shaft also has a necked section, which is designed to separate the corresponding one-way bearings if someone suddenly partially opens the back door while the operating handle is still partially inserted into the operating shaft during the grounding trip rotation of the operating shaft. This prevents the tripping operation from being performed even when the operating shaft is rotated, ensuring safety.

[0055] The operating shaft 5 is further fixed with a radially extending pin 101 at one end away from the operating hole 12. The elastic element is a retraction spring 102 fitted around the outer periphery of the operating shaft 5. The two ends of the retraction spring 102 press against the pin 101 and a corresponding operating shaft sleeve 10, respectively.

[0056] As a further improvement, such as Figure 4-6As shown, a rear door push plate 103 is also slidably connected to the mounting plate 4. The rear door push plate 103 is slidably arranged parallel to the axis of the mounting plate 4, with one end of the rear door push plate 103 abutting against the end of the operating shaft 5 away from the operating hole 12, and a rear door top pin 104 fixedly installed at the other end of the rear door push plate 103. The rear door top pin 104 abuts against the rear door 30 when the rear door 30 is closed. The rear door push plate 103 can separate the operating shaft 5 from the rear door 30, thereby reducing the length of the operating shaft 5.

[0057] The mounting plate 4 is also provided with a movable hole 41 for facilitating the extension and retraction of the rear door push plate 103. The rear door push plate 103 passes through the movable hole 41. The rear door push plate 103 is also provided with a vertical folding plate 1031 that is perpendicular to it. The vertical folding plate 1031 is in contact with one end of the operating shaft 5.

[0058] The anti-interlocking device for the floor-mounted handcart also includes an operating handle 105. The operating handle 105 includes a plug 1051 that can be inserted into the operating hole 12 and rotate the operating shaft 5, and a limiting cylinder 1052 integrally connected to the plug 1051 and having an outer diameter larger than the diameter of the operating hole 12. When the operating shaft 5 is away from the operating hole 12, the distance between the operating shaft 5 and the operating hole 12 is greater than the length of the plug 1051. The end of the operating shaft 5 near the operating hole 12 is an external hexagonal head 52, and the plug 1051 has an internal hexagonal hole that can engage with and rotate the external hexagonal head 52. When the operating handle is inserted through the operating hole in the side plate 1, the stepped surface of the operating handle contacts the front folding plate 11, limiting the insertion depth of the operating handle into the cabinet.

[0059] As a further improvement, such as Figure 7-9 As shown, the interlocking assembly includes a control component for controlling the two movable blocks to simultaneously extend out of or retract into the two through holes 21, and a linkage mechanism connecting the slide plate 3 and the control component. The linkage mechanism includes a V-shaped crank arm 106, a transmission pull plate 107, and a slider 108. The slider 108 is slidably connected to the guide rail 2 along the extension direction of the guide rail 2. The transmission pull plate 107 is fixedly disposed with the slider 108. The middle part of the V-shaped crank arm 106 is rotatably disposed relative to the guide rail 2. The two arms of the V-shaped crank arm 106 are respectively hinged to the slide plate 3 and the transmission pull plate 107 through pins. The control component is controlled by the sliding change of the slider 108.

[0060] When the slide plate 3 slides down, it drives the slider 108 to slide closer to the front folding plate 11 via the V-shaped crank arm 106 and the transmission pull plate 107, so that the slider 108 drives the control component to cause the two movable blocks to protrude out of the two through holes 21; when the slide plate 3 slides up, it drives the slider 108 to slide away from the front folding plate 11 via the V-shaped crank arm 106 and the transmission pull plate 107, so that the slider 108 drives the control component to cause the two movable blocks to retract into the two through holes 21.

[0061] The interlocking assembly controls the extension and retraction of the two movable blocks by sliding the slide plate 3, which drives the slider 108 to slide back and forth via the V-shaped crank arm 106 and the transmission pull plate 107. Compared with the existing interlocking shaft rotation-driven foot extension and retraction, it occupies less cabinet space, thus making the structure more compact and miniaturized.

[0062] As a preferred method, such as Figure 7-9 As shown, the control assembly includes an interlock box 109, a transmission plate 20, a reset spring 201, an inner slide plate 202, and a push plate 203; the two movable blocks are a locking block 204 and a locking plate bridge 205; the interlock box 109 is fixedly mounted on the guide rail 2, the slider 108 is provided with a straight guide groove 1081 extending in the front-to-back direction, and the locking plate bridge 205 is also fixedly provided with two guide pins 206 spaced apart in the front and back. The guide pins 206 both extend in the left-to-right direction, and the two guide pins 206 pass through the straight guide groove 1081 of the slider 108, so that the slider 108 can only slide back and forth relative to the interlock box 109;

[0063] The inner slide plate 202 is fixed to the interlock box 109 and extends to one end of the two guide pins 206. The two ends of the guide pins 206 are fixed to the inner slide plate 202 and the interlock box 109 respectively. The transmission plate 20 is movably connected to the two guide pins 206 through two holes. The locking plate bridge 205 is also movably connected to the two guide pins 206 through two holes and is located between the transmission plate 20 and the inner slide plate 202. When the transmission plate 20 is subjected to force and slides along the guiding direction of the guide pins 206 and closer to the inner slide plate 202, it can push the locking plate bridge 205 to move together, so that the locking plate bridge 205 can protrude from the corresponding through hole 21 of the guide rail 2. There are two reset springs 201, which are respectively fitted on the two guide pins 206. The two ends of the reset springs 201 press against the inner slide plate 202 and the locking plate bridge 205 respectively to provide a reverse reset force.

[0064] The push plate 203 is fixed on the slider 108. The push plate 203 is provided with a sliding groove 13 for guiding the locking block 204 to extend and retract left and right. The sliding groove 13 includes a wire groove 2031 extending in the front-back direction and an inclined groove 2032 connected to the wire groove 2031 and extending obliquely in the direction away from the locking plate bridge 205. The locking block 204 is located above the push plate 203 and is fixedly connected to a downward extending pin 207. The pin 207 is movably inserted in the sliding groove 13 of the push plate 203 and is also fixed to the transmission plate 20. Thus, when the pin 207 moves closer to the guide rail, it provides a force to the transmission plate to move closer to the guide rail.

[0065] When the slider 108 slides towards the front folding plate 11, the pin 207 is located at the groove 2031 of the slide groove 13 in the push plate 203, causing the locking block 204 and the locking plate bridge 205 to simultaneously protrude from the two through holes 21 of the guide rail 2. When the slider 108 slides away from the front folding plate 11, the pin 207 is located at the inclined groove 2032 of the slide groove 13 in the push plate 203, causing the locking block 204 and the locking plate bridge 205 to simultaneously retract into the two through holes 21 of the guide rail 2. The entire control assembly has a simple structure and is easy to manufacture.

[0066] The V-shaped crank arm 106 can also be rotatably connected to the crank arm seat 301, and the crank arm seat 301 is fixed to the guide rail 2.

[0067] As a preferred method, such as Figure 7 As shown, a reset spring 208 is also connected between the transmission pull plate 107 and the interlock box 109.

[0068] As a preferred method, such as Figure 1 As shown, the front folding plate 11 is provided with a vertically extending second slide groove 13, and the slide plate 3 is provided with a handle 32 that is movably inserted into the second slide groove 13; the front folding plate 11 is also rotatably connected with a padlock plate 209 for connecting with the handle 32 in the upward sliding position, and both the padlock plate 209 and the handle 32 are provided with lock holes. The padlock plate 209 can be locked to the handle 32 when closed, increasing security.

[0069] The working process of this embodiment:

[0070] 1. At work:

[0071] When the rear door 30 is closed, the rear door top pin 104 drives the rear door push plate 103 to overcome the force of the return spring 102, pushing the operating shaft 5 towards the front of the cabinet, close to the operating hole 12. Open the padlock plate 209 and insert the operating handle 105 into the operating hole 12 of the front folding plate 11, rotating it clockwise. The operating handle 105 drives the operating shaft 5 to rotate, which, under the action of the one-way needle roller bearing, drives the small gear of the main shaft 6 to rotate counterclockwise. The large gear of the main shaft 6 drives the main shaft 6 to rotate, thereby tripping the grounding switch.

[0072] After the grounding switch is tripped, the stop pin 61 installed on the main shaft 6 moves away from the limit position of the upper limit part 31 of the slide plate 3. When the operating handle 105 is pulled away from the operating hole 12, the slide plate 3, under the action of the reset spring 208, drives the V-shaped crank arm 106 to move through the transmission pull plate 107, causing the slide plate 3 to move upward. After the slide plate 3 is in position, it blocks the grounding switch operating hole 12.

[0073] Simultaneously, due to the action of the reset spring 208, the slider 108 moves backward towards the cabinet. The slide groove 13 designed by the push plate 203 mounted on the slider 108 drives the locking block 204 and the pin 207 to enter the field position from the inclined groove 2032, causing the locking block 204 to move linearly to the right of the cabinet. The locking plate bridge 205 also moves linearly to the right of the cabinet under the action of the reset spring 201. Finally, the locking plate bridge 205 and the locking block 204 retract into the guide rail 2. After closing the latch plate 209, the handcart 302 can be pushed from the test position to the working position. Figure 10 As shown, when the handcart 302 leaves the test position, the grounding switch locking plate 3021 on the handcart 302 always blocks the locking block 204, preventing the slide plate 3 from being pulled down and the grounding switch operating hole 12 from being opened. This effectively prevents the grounding switch from being closed while energized.

[0074] II. Test location;

[0075] When the handcart 302 is in the test position and the grounding switch is closed, the padlock plate 209 is opened, and the sliding plate 3 is pulled down. The sliding plate 3 drives the V-shaped crank arm 106 to move, and the crank arm drives the transmission pull plate 107 to move forward of the cabinet. The slider 108 installed on the pull plate and the push plate 203 move simultaneously, driving the pin 207 to move through the sliding groove 13 on the push plate 203. The locking block 204 and the locking plate bridge 205 inserted into the pin 207 protrude from the guide rail 2.

[0076] Insert the operating handle 105 into the operating hole 12 and rotate it counterclockwise. The handle drives the operating shaft 5 to rotate, which, under the action of another one-way needle roller bearing, drives the large gear of the main shaft 6 to rotate clockwise. The large gear of the main shaft 6 drives the main shaft 6 to rotate, thereby closing the grounding switch. After the grounding switch is closed, the stop pin 61 installed on the main shaft 6 rotates to the limit part 31, pressing the slide plate 3. When the handle is pulled out of the operating hole 12, the slide plate 3 cannot be reset, so as to keep the locking block 204 and the locking plate bridge 205 protruding from the guide rail 2.

[0077] When the padlock plate 209 is closed, the handcart 302 moves away from the test position, as follows: Figure 11 As shown, the lead screw locking plate 3022 on the handcart 302 is pushed into the handcart 302 by the locking plate bridge 205, making the handcart lead screw unable to move. This meets the requirement of preventing grounding during power supply.

[0078] Although the present invention has been illustrated and described through specific embodiments and alternative methods, it should be understood that various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, it should be understood that the present invention is not limited in any sense except by the appended claims and their equivalents.

Claims

1. A preventive interlocking device for a ground-operated handcart, characterized in that: The device includes a side panel, a front folding plate, an operation hole, and a guide rail extending in the front-rear direction. The guide rail has two through holes, one above the other, and each through hole contains a retractable movable block. A sliding plate is vertically slidably connected to the front folding plate. An interlocking assembly connects the sliding plate to the two movable blocks. When the sliding plate is in an upward sliding state, it blocks the operation hole and, through the interlocking assembly, causes the two movable blocks to simultaneously protrude out of the two through holes in the guide rail. When the sliding plate is in a downward sliding state, it opens the operation hole and, through the interlocking assembly, causes the two movable blocks to simultaneously retract back into the two through holes in the guide rail. A mounting plate is fixedly installed in the side plate, and an operating shaft is rotatably connected to the mounting plate. A main shaft is provided next to the operating shaft and is rotatably arranged relative to the mounting plate for controlling the opening and closing of the grounding switch. A transmission mechanism is also connected between the operating shaft and the main shaft for driving the main shaft to rotate during the rotation of the operating shaft. The operating shaft can extend and retract along its axial direction. When the rear door is closed, the operating shaft can move closer to the operating hole under the pressure of the rear door. An elastic element for driving the operating shaft to reverse reset is also connected between the operating shaft and the side plate. When the rear door is opened, the operating shaft moves away from the operating hole under the action of the elastic element. The main shaft is also fixed with a stop pin, and the slide plate is also fixed with a limiting part corresponding to the stop pin. During the forward and reverse rotation of the main shaft, the stop pin has a limiting state of being locked in the limiting part and a disengaged state of being released from the limiting part. When the main shaft rotates in one direction and controls the grounding switch to close, the stop pin locks in the limiting part to restrict the slide plate from moving upward. The interlocking assembly includes a control component for controlling the two movable blocks to simultaneously extend or retract into the two through holes, and a linkage mechanism connecting the slide plate and the control component. The linkage mechanism includes a V-shaped crank arm, a transmission pull plate, and a slider. The slider is slidably connected to the guide rail along the extension direction of the guide rail. The transmission pull plate is fixedly set to the slider. The middle part of the V-shaped crank arm is rotatably set relative to the guide rail. The two arms of the V-shaped crank arm are respectively hinged to the slide plate and the transmission pull plate through pins. The control component is controlled by the sliding change of the slider. When the slide plate slides down, it drives the slider to slide closer to the front folding plate via the V-shaped crank arm and the transmission pull plate, causing the slider drive control component to drive the two movable blocks to protrude out of the two through holes; when the slide plate slides up, it drives the slider to slide away from the front folding plate via the V-shaped crank arm and the transmission pull plate, causing the slider drive control component to drive the two movable blocks to retract into the two through holes.

2. The anti-interlocking device for a ground-operated handcart according to claim 1, characterized in that: The transmission mechanism includes a drive pinion sleeved on the outer periphery of the operating shaft and rotating synchronously with the operating shaft, and a main shaft gear fixedly disposed with the main shaft. The drive pinion meshes with the main shaft gear for transmission. Two one-way needle roller bearings are also sleeved on the outer periphery of the operating shaft. The drive pinion is fixedly sleeved on the outer ring of the two one-way needle roller bearings. The two one-way needle roller bearings are clearance-fitted with the operating shaft, and the two one-way needle roller bearings are installed in opposite directions.

3. The anti-interlocking device for a ground-operated handcart according to claim 2, characterized in that: The operating shaft is rotatably connected to the side plate by two operating shaft sleeves. The operating shaft sleeves are fixedly set relative to the mounting plate. The operating shaft is movably inserted in the two operating shaft sleeves. Two one-way needle roller bearings and a drive pinion are located between the two operating shaft sleeves.

4. The anti-interlocking device for a ground-operated handcart according to claim 2, characterized in that: The operating shaft is also provided with a neck section with a smaller diameter than the other sections. The length of the neck section is greater than the width of a single one-way needle roller bearing. When the rear door is opened, the neck section of the operating shaft is in the relative position of one of the one-way needle roller bearings under the action of the elastic element. When the rear door is closed, the neck section of the operating shaft is disengaged from the relative position of the corresponding one-way needle roller bearing.

5. The anti-interlocking device for a ground-operated handcart according to claim 1, characterized in that: A rear door push plate is also slidably connected to the mounting plate. The rear door push plate is slidably arranged parallel to the axis of the mounting plate. One end of the rear door push plate abuts against the end of the operating shaft away from the operating hole, and the other end of the rear door push plate is fixedly provided with a rear door top pin. The rear door top pin abuts against the rear door when the rear door is closed.

6. The anti-interlocking device for a ground-operated handcart according to claim 1, characterized in that: The control assembly includes an interlock box, a transmission plate, a reset spring, an inner slide plate, and a push plate; the two movable blocks are a locking block and a locking plate bridge; the interlock box is fixedly mounted on a guide rail, the slider is provided with a straight guide groove extending in the front-to-back direction, and the locking plate bridge is also fixedly provided with two guide pins spaced apart in the front and back. The guide pins extend in the left-to-right direction and pass through the straight guide groove of the slider, so that the slider can only slide back and forth relative to the interlock box; The inner slide plate is fixed to the interlocking box and extends to one end of the two guide pins. The two ends of the guide pins are fixed to the inner slide plate and the interlocking box, respectively. The transmission plate is movably connected to the two guide pins through two holes. The locking plate bridge is also movably connected to the two guide pins through two holes and is located between the transmission plate and the inner slide plate. When the transmission plate is subjected to force and slides along the guiding direction of the guide pins and closer to the inner slide plate, it can push the locking plate bridge to move together, so that the locking plate bridge can protrude from the corresponding through hole of the guide rail. There are two reset springs, which are respectively fitted on the two guide pins, and the two ends of the reset springs press against the inner slide plate and the locking plate bridge, respectively, to provide a reverse reset force. The push plate is fixed on the slider. The push plate is provided with a sliding groove for guiding the locking block to extend and retract left and right. The sliding groove includes a wire groove extending in the front-back direction and an inclined groove connected to the wire groove and extending obliquely in the direction away from the locking plate bridge. The locking block is located above the push plate and is fixedly connected with a downward extending pin. The pin is movably inserted in the sliding groove of the push plate and is also fixed to the transmission plate. When the slider slides towards the front folding plate, the pin is located in the groove of the slide in the push plate, so that the locking block and the locking plate bridge protrude from the two through holes of the guide rail at the same time. When the slider slides away from the front folding plate, the pin is located in the inclined groove of the slide in the push plate, so that the locking block and the locking plate bridge retract into the two through holes of the guide rail at the same time.

7. A preventive interlocking device for a ground-operated handcart according to claim 6, characterized in that: A reset spring is also connected between the transmission pull plate and the interlock box.

8. The anti-interlocking device for a ground-operated handcart according to claim 1, characterized in that: The front folding plate is provided with a vertically extending second slide groove, and the slide plate is provided with a handle that is movably inserted in the second slide groove; the front folding plate is also rotatably connected with a padlock plate for connecting with the handle in the upward sliding position, and both the padlock plate and the handle are provided with lock holes.

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