A deviation-correcting device for coal transportation

Abstract

The present invention relates to the technical field of coal transportation, and specifically to a deviation correction device for coal transportation, comprising: a frame; a deviation correction mechanism for correcting the deviation of a conveyor belt; the deviation correction mechanism comprises: a movable frame rotatably mounted on the frame; a center roller rotatably mounted on the movable frame; a connecting frame symmetrically arranged on both sides of the center roller; side rollers rotatably mounted on the connecting frame; a linkage gear coaxially connected to the movable frame; a detection component for detecting the deviation of the conveyor belt; and a linkage component for driving the side rollers to move. In the present invention, through the setting of the deviation correction mechanism, when the conveyor belt deviates, the height of the side roller on the side of the deviation is raised, and at the same time, the side roller is deflected according to the deviation direction, so as to realize automatic and rapid deviation correction of the conveyor belt.

Description

Technical Field

[0001] The invention relates to the technical field of coal transportation, and in particular to a deviation-correcting device for coal transportation. Background Art

[0002] Coal is usually transported using conveyor belts. Conveyor belts, also known as transport belts, are rubber, fiber, metal composite products, or plastic and fabric composite products used to carry and transport materials during transportation. They are widely used in mining, metallurgy, coal and other industries.

[0003] In actual use, conveyor belt deviation is one of the most common faults in the operation of conveyor belt conveyors. Taking coal block conveyors as an example, the rollers used generally make the conveyor belt higher than the center on both sides to facilitate the transportation of block materials, which can prevent coal blocks from spilling during transportation to a certain extent. When the conveyor belt deviates during operation, the conveyor belt deviates to one side of the roller. At this time, with the increase of the running length, the degree of deviation will gradually increase, and the height difference on both sides of the conveyor belt edge will gradually increase. The coal blocks on the conveyor belt will always gather in the depression. Therefore, after the conveyor belt deviates, the coal blocks will slide on the conveyor belt, causing the coal blocks on the conveyor belt to roll off the conveyor belt, affecting work efficiency. The conveyor belt deviation may also cause abnormal friction with the frame, resulting in severe wear on the edge of the conveyor belt, affecting its service life. In severe cases, it may even produce sparks and cause major safety accidents.

[0004] A Chinese patent with application number CN202122661125.7 discloses a deviation correction device for a coal mine belt conveyor, which relates to the field of coal mining, including a bottom plate, a slide groove is provided in the bottom plate, and two movable plates are slidably connected in the slide groove, and a rectangular sleeve is fixedly connected on the upper side of the movable plate. The utility model rotates the worm by a handle two, and the worm can drive the threaded barrel one to rotate by cooperating with the worm wheel, and the threaded barrel two is rotated by a handle one, and the threaded barrel two can drive the roller group to move by cooperating with the screw rod two, the rectangular sleeve, the fixed plate three and the U-shaped plate, and then the tooth plate is driven to move by an electric push rod, and the tooth plate can drive the connecting plate two and the roller group to swing by cooperating with the gear and the rotating shaft, so that the roller group is tilted, and the conveyor belt can be pushed by the roller group to displace the conveyor belt, so that the conveyor device can be corrected, and the device has multiple adjustment functions, good adjustability and adaptability, and effectively solves the problems raised in the background technology.

[0005] However, the deviation correction device in the above patent is adjusted manually and cannot be automatically adjusted according to the deviation of the conveyor belt, so that the deviation of the conveyor belt cannot be corrected in time, resulting in poor use effect.

[0006] Therefore, it is necessary to provide a new technical solution to overcome the above-mentioned defects. Summary of the invention

[0007] The object of the present invention is to provide a deviation-correcting device for coal transportation which can effectively solve the above-mentioned technical problems.

[0008] In order to achieve the purpose of the present invention, the following technical scheme is adopted: A deviation correction device for coal transportation, comprising: a frame; a deviation correction mechanism for correcting the deviation of a conveyor belt; The deviation correction mechanism includes: a movable frame rotatably mounted on the frame; a center roller rotatably mounted on the movable frame; a connecting frame symmetrically arranged on both sides of the center roller; side rollers rotatably mounted on the connecting frame; a linkage gear coaxially connected to the movable frame; a detection component for detecting the deviation of the conveyor belt; and a linkage component for driving the side rollers to move.

[0009] Furthermore, the detection assembly includes: a bracket slidably mounted on the frame; a vertical roller arranged on the bracket; a linkage rack fixedly mounted on the bracket; a limiting member for limiting the linkage rack; and an auxiliary unit for assisting in correcting the conveyor belt.

[0010] Furthermore, the auxiliary unit includes: a circular groove and a movable groove opened on the bracket; a mounting rod slidably installed in the circular groove; a connecting rod slidably installed in the movable groove; a guide plate fixedly installed on the frame; and an oblique groove opened on the guide plate.

[0011] Furthermore, the circular groove is communicated with the movable groove, the mounting rod is fixedly connected with the connecting rod, and the connecting rod is slidably installed in the inclined groove.

[0012] Furthermore, the limiting member includes: a limiting rod slidably connected to the bracket; a slide rail fixedly installed on the frame; a slider slidably installed on the slide rail; and the slider is fixedly connected to the linkage rack.

[0013] Furthermore, the linkage assembly includes: a vertical rod fixedly connected to the connecting frame; a horizontal rod fixedly connected to the vertical rod; a limit frame fixedly connected to the horizontal rod; a fixed plate for limiting the vertical rod; an arc plate fixedly installed on the frame; a guide groove and a slide groove opened on the arc plate; and a rolling member rotatably installed on the fixed plate.

[0014] Furthermore, the fixing plate is fixedly mounted on the connecting frame, and the arc-shaped plate is fixedly mounted on the frame.

[0015] Furthermore, the guide groove is S-shaped, and the cross bar is slidably installed in the guide groove.

[0016] Furthermore, the slide groove is arc-shaped, and the rolling element is slidably installed in the slide groove.

[0017] Furthermore, it is characterized by further comprising: a feedback mechanism for providing feedback on the deviation correction result; The feedback mechanism includes: a fixed tube fixedly mounted on the frame; a movable block slidably mounted in the fixed tube; a movable rod fixedly connected to the movable block; a proximity switch fixedly mounted in the fixed tube; and a reset spring driving the movable block to reset.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a deviation correction device for coal transportation. By setting a deviation correction mechanism, when a conveyor belt deviates, the height of the side roller on the deviation side is raised, and the side roller is deflected according to the deviation direction, so that the conveyor belt is automatically and quickly corrected. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0020] Figure 1 It is a three-dimensional schematic diagram of a deviation-correcting device for coal transportation according to the present invention; Figure 2 It is a schematic cross-sectional view of a component frame of a deviation-correcting device for coal transportation according to the present invention; Figure 3 A deviation correction device for coal transportation according to the present invention Figure 2 Enlarged view of point A in the middle; Figure 4 It is a three-dimensional schematic diagram of the linkage gear of the component of a deviation correction device for coal transportation of the present invention; Figure 5 It is a cross-sectional schematic diagram of a component support of a deviation-correcting device for coal transportation according to the present invention; Figure 6 It is a three-dimensional schematic diagram of a side roller component of a deviation correction device for coal transportation according to the present invention.

[0021] In the figure: 1. Frame; 2. Correction mechanism; 21. Movable frame; 22. Center roller; 23. Side roller; 24. Connecting frame; 25. Interlocking gear; 26. Detection assembly; 261. Bracket; 262. Vertical roller; 263. Interlocking rack; 264. Limiting piece; 2641. Limiting rod; 2642. Sliding block; 2643. Slide rail; 265. Auxiliary unit; 2651. Mounting rod; 2652. Interlocking rod; 2653. Guide plate; 2654. Bevel groove; 27. Interlocking assembly; 271. Vertical rod; 272. Cross rod; 273. Limiting frame; 274. Arc plate; 275. Guide groove; 276. Slide groove; 277. Rolling element; 278. Fixed plate; 3. Feedback mechanism; 31. Fixed tube; 32. Movable rod; 33. Movable block; 34. Proximity switch; 35. Reset spring. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are partial embodiments of the present invention, rather than all embodiments.

[0023] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention. When a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a centered component. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centered component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a centered component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0024] like Figures 1 to 6 As shown, the present invention provides a deviation correction device for coal transportation, comprising: a frame 1; and a deviation correction mechanism 2 for correcting the deviation of a conveyor belt.

[0025] The deviation correction mechanism 2 includes: a movable frame 21 rotatably mounted on the frame 1; a center roller 22 rotatably mounted on the movable frame 21; a connecting frame 24 symmetrically arranged on both sides of the center roller 22; a side roller 23 rotatably mounted on the connecting frame 24; a linkage gear 25 coaxially connected to the movable frame 21; a detection component 26 for detecting the deviation of the conveyor belt; and a linkage component 27 for driving the side rollers 23 to move.

[0026] In the present invention, the conveyor belt moves from the center roller 22 toward the detection assembly 26, and the running conveyor belt drives the center roller 22 and the side rollers 23 to rotate.

[0027] The detection component 26 includes: a limiting opening opened on the frame 1, a bracket 261 slidably installed in the limiting opening, two brackets 261 are provided, and are symmetrically arranged on the frame 1, and the conveyor belt passes through the two brackets 261; a vertical roller 262 is provided on the bracket 261, two vertical rollers 262 are provided, corresponding to the two brackets 261 respectively, and both sides of the conveyor belt are in contact with the adjacent vertical rollers 262; a linkage rack 263 fixedly installed on the bracket 261, the linkage rack 263 and the linkage gear 25 are meshed with each other; a limiting member 264 for limiting the linkage rack 263; an auxiliary unit 265 for assisting in correcting the conveyor belt.

[0028] The limiting member 264 includes: a limiting rod 2641 slidably connected to the bracket 261, both ends of the limiting rod 2641 are fixedly installed in the limiting opening; a slide rail 2643 fixedly installed on the frame 1; a slider 2642 slidably installed on the slide rail 2643; and the slider 2642 is fixedly connected to the linkage rack 263.

[0029] When the bracket 261 moves, it can drive the linkage rack 263 to move. Through the setting of the limiting rod 2641 and the limiting opening, the bracket 261 can be limited when moving, thereby improving the stability of the bracket 261 when moving, thereby improving the stability of the linkage rack 263 when moving. When the linkage rack 263 moves, it can drive the slider 2642 to slide on the slide rail 2643, thereby limiting the linkage rack 263, further improving the stability of the movement of the linkage rack 263, and thus making the linkage rack 263 always mesh with the linkage gear 25.

[0030] When the conveyor belt starts to deviate, the edge height of one side of the conveyor belt will increase, and the edge height of the other side of the conveyor belt will decrease. When the increased edge of the conveyor belt abuts against the vertical roller 262, the vertical roller 262 is squeezed by the conveyor belt, thereby driving the vertical roller 262 to move. The vertical roller 262 drives the bracket 261 to move horizontally along the extrusion direction of the conveyor belt. The bracket 261 drives the interlocking rack 263 to move, and the interlocking rack 263 drives the interlocking gear 25 to rotate, thereby driving the movable frame 21 to rotate. The movable frame 21 drives the center roller 22 and the interlocking assembly 27 to rotate, and the interlocking assembly 27 drives the side rollers 23 to rotate, thereby realizing rapid deviation correction of the conveyor belt.

[0031] As the appended Figure 1 As shown, when the conveyor belt deviates to the left, the vertical roller 262 on the left is squeezed, thereby driving the vertical roller 262 to move horizontally to the left. At this time, the linkage rack 263 moves horizontally to the left, thereby driving the linkage gear 25 to rotate clockwise. The linkage gear 25 drives the movable frame 21 to rotate clockwise, thereby driving the center roller 22 and the side roller 23 to rotate clockwise, so that the side roller 23 on the left is close to the vertical roller 262 on the left, and the side roller 23 on the right is away from the vertical roller 262 on the right. At this time, the center roller 22 and the side roller 23 are tilted, so that the center roller 22 and the side roller 23 rotate at a certain angle, so that the center roller 22 and the side roller 23 are not perpendicular to the forward direction of the conveyor belt, thereby generating a force pointing to the center of the conveyor belt, thereby guiding the conveyor belt to reset and realizing the rapid deviation correction of the conveyor belt; When the conveyor belt deviates to the right, the correction method is the same as above.

[0032] The auxiliary unit 265 includes: a circular groove and a movable groove provided on the bracket 261; a mounting rod 2651 slidably installed in the circular groove; a connecting rod 2652 slidably installed in the movable groove; a guide plate 2653 fixedly installed on the frame 1; an oblique groove 2654 provided on the guide plate 2653; the circular groove is connected to the movable groove, the mounting rod 2651 is fixedly connected to the connecting rod 2652, and the connecting rod 2652 is slidably installed in the oblique groove 2654.

[0033] When the raised side of the conveyor belt edge comes into contact with the vertical roller 262, the vertical roller 262 is squeezed by the conveyor belt, thereby driving the vertical roller 262 to move. When the vertical roller 262 drives the bracket 261 to move horizontally along the extrusion direction of the conveyor belt, the bracket 261 drives the linkage rack 263 to move, and synchronously drives the installation rod 2651 to move. The installation rod 2651 drives the linkage rod 2652 to move along the path of the inclined groove 2654. When the linkage rod 2652 moves along the path of the inclined groove 2654, it can drive the vertical roller 262 to move upward.

[0034] As the appended Figure 1As shown, when the conveyor belt deviates to the left, the vertical roller 262 on the left is squeezed, thereby driving the vertical roller 262 on the left to move. When the vertical roller 262 drives the bracket 261 to move horizontally along the squeezing direction of the conveyor belt, the bracket 261 drives the mounting rod 2651 to move to the left, and the mounting rod 2651 drives the linkage rod 2652 to move along the path of the inclined groove 2654. When the linkage rod 2652 moves along the path of the inclined groove 2654, it can drive the vertical roller 262 on the left to move upward. At the same time, when the linkage rod 2652 corresponding to the right vertical roller 262 moves along the path of the inclined groove 2654, the right vertical roller 262 can be driven to move downward; When the conveyor belt deviates to the left, the vertical roller 262 on the left rises and the vertical roller 262 on the right lowers. At this time, the vertical roller 262 on the left gives the conveyor belt a reverse upward correction force, thereby further realizing the rapid correction of the conveyor belt.

[0035] When the conveyor belt deviates to the right, the correction method is the same as above.

[0036] From the above, it can be known that when the conveyor belt deviates, the height of the vertical roller 262 on the deviated side is raised, and the raised vertical roller 262 gives the conveyor belt a reverse upward correction force, further realizing the rapid correction of the conveyor belt, so that the conveyor belt that has been corrected from deviation returns to the correct running track.

[0037] In the present invention, by setting the detection component 26, on the one hand, when the conveyor belt deviates, the center roller 22 and the side roller 23 can be driven to rotate by a certain angle, so that the center roller 22 and the side roller 23 are not perpendicular to the forward direction of the conveyor belt, thereby generating a force pointing to the center of the conveyor belt, thereby guiding the conveyor belt to reset and realize the rapid deviation correction of the conveyor belt; on the other hand, the vertical roller 262 on the deviated side is driven to rise in height, and the raised vertical roller 262 gives the conveyor belt a reverse upward tilting correction force, further realizing the rapid deviation correction of the conveyor belt, so that the conveyor belt that has been corrected to deviate returns to the correct running track.

[0038] The linkage assembly 27 includes: a vertical rod 271 fixedly connected to the connecting frame 24; a horizontal rod 272 fixedly connected to the vertical rod 271; a limit frame 273 fixedly connected to the horizontal rod 272, and the limit frame 273 is slidably installed on the movable frame 21; a fixed plate 278 for limiting the vertical rod 271, the fixed plate 278 is fixedly installed on the movable frame 21, and the vertical rod 271 is slidably installed on the fixed plate 278; an arc plate 274 fixedly installed on the frame 1, and two arc plates 274 are provided, which are symmetrically arranged on both sides of the movable frame 21, and the arc centers of the two arc plates 274 coincide with the axis of rotation of the movable frame 21; a guide groove 275 and a slide groove 276 are provided on the arc plate 274; a rolling member 277 rotatably installed on the fixed plate 278, and the rolling member 277 is preferably a bull's eye ball.

[0039] The guide groove 275 is S-shaped, and the cross bar 272 is slidably installed in the guide groove 275; the slide groove 276 is arc-shaped, and the slide groove 276 is opened along the curvature of the arc plate 274, and the rolling member 277 is slidably installed in the slide groove 276; when the movable frame 21 drives the fixed plate 278 to rotate, it can drive the rolling member 277 to slide in the slide groove 276, thereby improving the stability of the fixed plate 278 during rotation, and further improving the stability of the movable frame 21 during rotation.

[0040] When the movable frame 21 rotates, it can drive the fixed plate 278 and the limit frame 273 to rotate, and then drive the cross bar 272 and the vertical bar 271 to rotate, thereby realizing the rotation of the side roller 23. Since the cross bar 272 is slidably installed in the guide groove 275, and the guide groove 275 is S-shaped, the cross bar 272 can move along the path of the guide groove 275.

[0041] As the appended Figure 1 As shown, when the conveyor belt deviates to the left, the side roller 23 on the left is close to the vertical roller 262 on the left, and the side roller 23 on the right is away from the vertical roller 262 on the right; at this time, the left cross bar 272 moves to the highest point of the guide groove 275, and the right cross bar 272 moves to the lowest point of the guide groove 275, thereby raising the side roller 23 on the left and lowering the side roller 23 on the right. At this time, the side roller 23 on the left gives the conveyor belt a reverse upward tilting correction force, thereby further realizing the rapid correction of the conveyor belt.

[0042] When the conveyor belt deviates to the right, the correction method is the same as above.

[0043] From the above, it can be seen that when the conveyor belt deviates, the height of the side roller 23 on the deviated side is raised, and at the same time, the side roller 23 is deflected according to the deviation direction. On the one hand, the conveyor belt is quickly corrected and the conveyor belt that has been corrected returns to the correct running track; on the other hand, it prevents coal blocks from spilling during transportation, thereby ensuring the transportation effect.

[0044] In the present invention, by setting the deviation correction mechanism 2, when the conveyor belt deviates, the side roller 23 on the deviated side is raised in height, and the side roller 23 is deflected according to the deviation direction, thereby realizing automatic and rapid deviation correction of the conveyor belt.

[0045] It also includes: a feedback mechanism 3 for feeding back the correction result; the feedback mechanism 3 includes: a fixed tube 31 fixedly mounted on the frame 1; a movable block 33 slidably mounted in the fixed tube 31; a movable rod 32 fixedly connected to the movable block 33, the other end of the movable rod 32 passes through the inner cavity of the fixed tube 31 and is fixedly connected to the bracket 261; a proximity switch 34 fixedly mounted in the fixed tube 31; a reset spring 35 for driving the movable block 33 to reset, one end of the reset spring 35 is fixedly connected to the fixed tube 31, and the other end of the reset spring 35 is fixedly connected to the movable block 33; a signal light is installed on the frame 1, and the signal light is electrically connected to the proximity switch 34.

[0046] When the vertical roller 262 on one side of the conveyor belt is squeezed by the conveyor belt, it can drive the bracket 261 to move, and the bracket 261 drives the movable rod 32 to move, and the movable rod 32 drives the movable block 33 to approach the proximity switch 34. At this time, the proximity switch 34 senses that the movable block 33 is approaching, so that the signal light flashes and drives the reset spring 35 to deform. At this time, the staff can judge the deviation of the conveyor belt by observing the signal light.

[0047] When the conveyor belt returns to the correct position, the vertical roller 262 on the side where the conveyor belt has deviated is not squeezed by the conveyor belt. Under the elastic force of the reset spring 35, the movable block 33 can be reset, and the movable block 33 can reset the movable rod 32. The movable rod 32 can reset the bracket 261, thereby driving the movable frame 21 to reset, and then driving the center roller 22 and the side roller 23 to reset. At this time, the signal light no longer flashes.

[0048] When the signal light flashes for a long time, it indicates that the conveyor belt has not returned to the correct position. At this time, the staff can quickly check the correcting mechanism 2 at that location to avoid the correcting mechanism 2 being unable to reset the conveyor belt due to a malfunction.

[0049] The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. Machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The content not described in detail in this specification belongs to the prior art known to professional and technical personnel in this field.

[0050] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A deviation correction device for coal transportation, characterized in that: include: frame; A deviation correction mechanism for correcting the conveyor belt; The deviation correction mechanism includes: a movable frame rotatably mounted on the frame; a center roller rotatably mounted on the movable frame; a connecting frame symmetrically arranged on both sides of the center roller; side rollers rotatably mounted on the connecting frame; a linkage gear coaxially connected to the movable frame; a detection component for detecting the deviation of the conveyor belt; and a linkage component for driving the side rollers to move.

2. A deviation-correcting device for coal transportation according to claim 1, characterized in that: The detection assembly includes: a bracket slidably mounted on the frame; a vertical roller arranged on the bracket; a linkage rack fixedly mounted on the bracket; a limiting member for limiting the linkage rack; and an auxiliary unit for assisting in deviation correction of the conveyor belt.

3. A deviation-correcting device for coal transportation as claimed in claim 2, characterized in that: The auxiliary unit comprises: a circular groove and a movable groove provided on the bracket; a mounting rod slidably installed in the circular groove; a linkage rod slidably installed in the movable groove; a guide plate fixedly installed on the frame; and an oblique groove provided on the guide plate.

4. A deviation-correcting device for coal transportation as claimed in claim 3, characterized in that: The circular groove is communicated with the movable groove, the mounting rod is fixedly connected with the linkage rod, and the linkage rod is slidably mounted in the inclined groove.

5. A deviation-correcting device for coal transportation as claimed in claim 2, characterized in that: The limiting member comprises: a limiting rod slidably connected to the bracket; a slide rail fixedly mounted on the frame; a slider slidably mounted on the slide rail; and the slider is fixedly connected to the linkage rack.

6. A deviation-correcting device for coal transportation according to claim 1, characterized in that: The linkage assembly includes: a vertical rod fixedly connected to the connecting frame; a horizontal rod fixedly connected to the vertical rod; a limit frame fixedly connected to the horizontal rod; a fixed plate for limiting the vertical rod; an arc plate fixedly installed on the frame; a guide groove and a slide groove opened on the arc plate; and a rolling member rotatably installed on the fixed plate.

7. A deviation-correcting device for coal transportation as claimed in claim 6, characterized in that: The fixing plate is fixedly mounted on the connecting frame, and the arc-shaped plate is fixedly mounted on the frame.

8. A deviation-correcting device for coal transportation as claimed in claim 6, characterized in that: The guide groove is S-shaped, and the cross bar is slidably installed in the guide groove.

9. A deviation-correcting device for coal transportation as claimed in claim 6, characterized in that: The slide groove is arc-shaped, and the rolling element is slidably installed in the slide groove.

10. A deviation-correcting device for coal transportation as claimed in claim 1, characterized in that: It also includes: a feedback mechanism for providing feedback on the correction results; The feedback mechanism includes: a fixed tube fixedly mounted on the frame; a movable block slidably mounted in the fixed tube; a movable rod fixedly connected to the movable block; a proximity switch fixedly mounted in the fixed tube; and a reset spring driving the movable block to reset.

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