CN106877236A - Fast and reliable safety-type grounding wire clamp apparatus - Google Patents

Abstract

The present invention relates to a fast, reliable and safe ground wire clamp, which includes a fixed clamp (1) and a movable clamp (2). The upper part of the fixed clamp (1) is provided with a hook (12), and the movable clamp (2) ) is the slide bar (21) installed in the slide hole of the fixed jig, the upper end of the slide bar is provided with a movable jig head (22), and the slide hole is provided with a compression spring one (25) set on the slide bar , a connecting sleeve (4) is provided under the fixing fixture (1), and several steel ball holes (41) are provided on the side wall of the connecting sleeve, steel balls (42) are respectively installed in each steel ball hole, and a ring is provided on the outer wall of the slider Steel ball groove (26), the below of fixed fixture is provided with control cover (5), is provided with stage clip two (43) that is sleeved on the outside of connection cover (4) in the control cover. Using it can ensure reliable contact between the grounding wire fixture and the overhead wire, and it is convenient and fast to remove and hang the grounding wire, which is conducive to shortening the maintenance time of power outages and improving the working speed without affecting the normal power supply.

Description

Fast, reliable and safe ground wire fixture

technical field

The invention relates to a power line grounding device, in particular to a grounding line fixture.

Background technique

In order to ensure the safety of the staff during the power outage maintenance of the overhead power line, it is required to hang a grounding wire between the power outage operation line and the grounding electrode to prevent accidental power transmission and induction from causing danger to the staff. At present, the grounding wire clamps used in my country's power system mainly have two structures, one is clamped by leaf springs, and the other is clamped by bolts. The defect that the contact effect between the overhead lines is not reliable enough leads to the unreliable connection between the overhead line and the grounding electrode after the grounding wire is hung, and accidents that cause electric shock to the staff due to unreliable grounding will occur, causing unnecessary Danger. In order to avoid the occurrence of dangerous situations, sometimes it is necessary to hang multiple groups of grounding wires to increase the reliability of the grounding, which brings a lot of unnecessary troubles to the maintenance operation. The existing grounding wire fixture also has the disadvantage of being inconvenient to hang on and take off from the overhead wire, which is not conducive to shortening the maintenance time of the power outage and improving the operating speed, and will affect the normal power supply.

Contents of the invention

The purpose of the present invention is to solve the problem that the contact between the existing grounding wire fixture and the overhead wire is not reliable enough, the personal safety of the staff cannot be guaranteed, and the removal and hanging of the grounding wire is not convenient and fast enough, which is not conducive to shortening the power outage maintenance time and improving the operating speed, which will affect To solve the defects of normal power supply, a fast, reliable and safe grounding wire fixture is provided.

The technical solution of the present invention is: it includes a fixed fixture and a movable fixture, the fixed fixture is provided with a grounding wire connection device, and the upper part of the fixed fixture is provided with a side connected to the fixed fixture and connected to the fixed fixture. There is a hook for the overhead line hanging groove in the lower end direction, and a sliding hole is provided at the position opposite to the overhead line hanging groove on the fixed fixture along the up and down direction. The upper end of the jig is provided with a movable jig head between the sliding hole and the hook. The movable jig head is provided with an overhead wire clamping groove that matches upwardly with the overhead wire hanging groove on the fixed jig. The movable jig head and the hook The outer side of the matching position is provided with a pull ring matched with the pull rod of the operating rod, and a compression spring 1 set on the slide rod is arranged in the slide hole, the upper end of the compression spring 1 is matched with the slide rod, and the lower end is matched with the fixing fixture The upper elastic force is formed on the movable jig, and the upper end of the fixed jig is fixedly connected to the lower end of the fixed jig and the connecting sleeve is slidably fitted on the outside of the slide bar. The side wall of the connecting sleeve under the fixed jig is provided with a circle of several Steel ball holes, each steel ball hole is equipped with a steel ball with a diameter larger than the thickness of the side wall of the connecting sleeve, and the outer wall of the sliding rod that is slidably matched with the position where the connecting sleeve is provided with steel ball holes is provided with a circle of ring-shaped steel ball grooves that match the steel balls , the lower part of the fixed fixture is provided with a control sleeve that slides on the outside of the connecting sleeve. The inner hole at the upper end of the control sleeve is a large-diameter hole 1 that matches with each steel ball. Small-diameter holes, the inner wall of the control sleeve between the large-diameter hole 1 and the small-diameter hole is a guiding tapered surface with a large upper part and a smaller lower one. The diameter hole 2 is equipped with a compression spring 2 set outside the connecting sleeve. The lower end of the connecting sleeve is provided with an end sleeve that is slidably matched with the large-diameter hole 2 of the control sleeve and fixedly installed outside the lower end of the connecting sleeve. Compression spring 2 The upper end of the upper end is matched with the inner end face of the control sleeve above the large diameter hole two, and the lower end is matched with the upper end face of the end sleeve.

The technical effects of the present invention are: the use of it can ensure reliable contact between the grounding wire clamp and the overhead wire, the removal and hanging of the grounding wire is convenient and fast, and it is beneficial to shorten the power-off maintenance time and improve the working speed without affecting the normal power supply. It is easy to operate and use, with fast operation speed and simple operation method. After hanging on the overhead line, you only need to pull the operating lever to hold it firmly on the overhead line. swing and slide on the ground, which is conducive to reliable grounding. When taking off the overhead line, you only need to use the operating lever to pull the grounding wire clamp to open on the overhead line, and you can easily take it off from the overhead line. It can effectively save the time for picking up the grounding wire, and it is fast and easy to operate. Safe, reliable and convenient.

Description of drawings

Fig. 1 is a three-dimensional sectional view one of an embodiment of the present invention;

Fig. 2 is a perspective view 2 of an embodiment of the present invention;

Fig. 3 is a three-dimensional structure diagram of the operating rod head matched with the embodiment of the present invention.

detailed description

As shown in Figure 1 and Figure 2, it includes a fixed fixture 1 and a movable fixture 2. The fixed fixture 1 is provided with a grounding wire connection device 3, and the upper part of the fixed fixture 1 is provided with a side connected to the fixed fixture 1. In one piece, the hook 12 of the overhead line hanging groove 11 is provided toward the lower end of the fixed fixture 1, and the position opposite to the overhead line hanging groove 11 on the fixed fixture 1 is provided with a sliding hole 13 along the up and down direction, and the lower part of the movable fixture 2 For sliding up and down the slide bar 21 installed in the slide hole 13, the upper end of the slide bar 21 is provided with a movable fixture head 22 between the slide hole 13 and the hook 12, and the movable fixture head 22 is provided with an upward and fixed fixture. The overhead wire hanging groove 11 on 1 is matched with the overhead wire clamping groove 23, and the outer side of the matching position of the movable fixture head 22 and the hook 12 is provided with a pull ring 24 matched with the operating rod pull rod, and the sliding hole 13 is provided with The compression spring one 25 that is set on the slide bar 21, the upper end of the compression spring one 25 cooperates with the slide bar 21, and the lower end cooperates with the fixed fixture 1 to form an upper elastic force on the movable fixture 2, and an upper end is arranged below the fixed fixture 1 It is fixedly connected with the lower end of the fixed clamp 1 and is slidably fitted on the connecting sleeve 4 on the outside of the slide bar 21. The side wall of the connecting sleeve 4 below the fixed clamp 1 is provided with a circle of several steel ball holes 41 along the circumference, and each steel ball hole 41 is respectively A steel ball 42 with a diameter greater than the thickness of the side wall of the connecting sleeve 4 is installed, and the outer wall of the slide bar 21 that is slidably matched with the position where the connecting sleeve 4 is provided with the steel ball hole 41 is provided with a circle of ring-shaped steel ball grooves 26 that match the steel balls 42, The bottom of the fixed fixture 1 is provided with a control sleeve 5 that is slidingly sleeved outside the connecting sleeve 4. The upper end inner hole of the control sleeve 5 is a large-diameter hole 51 matched with each steel ball 42, and the bottom of the large-diameter hole 51 is a The small-diameter hole 52 that is slidingly fitted on the outer wall of the connecting sleeve 4, the inner wall of the control sleeve 4 between the large-diameter hole 51 and the small-diameter hole 52 is a guide tapered surface that is large and small, and the inner hole of the control sleeve 5 below the small-diameter hole is The second large-diameter hole 53 whose internal diameter is larger than the small-diameter hole 52 is provided with a compression spring 2 43 set outside the connecting sleeve 4, and the lower end of the connecting sleeve 4 is provided with a large-diameter hole on the outer wall and the control sleeve 5 The two 53 phases are slidably matched and fixedly installed on the end sleeve 6 outside the lower end of the connecting sleeve 4, the upper end of the pressure spring two 43 is matched with the inner end surface of the control sleeve 5 above the large diameter hole two 53, and the lower end is matched with the upper end surface of the end sleeve 6 .

The side wall of the lower end of the control sleeve 5 is provided with a bar-shaped hole 54 in the up-and-down direction, and the bar-shaped hole 54 is provided with a limiter where one end slides with the bar-shaped hole 54 and the other end is radially installed on the end sleeve 6 through threads. The top wire 61, the inner wall of the end sleeve 6 is provided with an internal thread, the end sleeve 6 is installed on the external thread of the lower end of the connecting sleeve 4 through the internal thread, and the radially opposite positions on the lower end surface of the end sleeve 6 are respectively provided for installation. And disassemble the slot 62 of the end cover 6.

The grounding wire connecting device 3 is composed of a grounding wire socket 31 which is located on the side wall of the fixing fixture 1 outside the sliding hole 13 and opens downward, two pressure wire plates 32 and two pressure wire bolts 33, and the two pressure wire bolts 33 are mounted on the side wall of the fixing fixture 1 by threading along the horizontal direction of the grounding wire jack 31 respectively. 32 are riveted together and are rotated and matched to press the grounding wire by the pressure plate 32.

The upper end of the slide bar 21 is connected with the movable fixture 2 through an external thread. The movable jig head 22 is provided with a guide slider 27 toward the side where the hook 12 is connected with the fixed jig 1, and the fixed jig 1 is provided with a chute 14 that is slidably matched with the guide slider 27 along the axial direction of the slide hole 13. . The other end of the hook 12 connected with the fixed fixture 1 is spaced along the direction perpendicular to the overhead line hanging groove 11 and has a plurality of bar-shaped notches 15 extending to the end of the hook 12. The movable fixture head 22 and the hook 12 The matching position of each bar-shaped notch 15 is provided with a plurality of combs 28 and hooks 12 that cross and cooperate with each bar-shaped notch 15 to ensure the clamping effect on the overhead line and increase the up and down sliding stroke of the movable fixture 2. The positions corresponding to the end of the bar-shaped notch 15 and the end of the movable fixture head 22 provided with the comb teeth 28 are respectively bent in opposite directions to form an arc-shaped opening for the introduction of overhead wires. The pull ring 24 is located below the comb teeth 28 in the middle and is located on the movable fixture head 22 and outside the side wall of the fixed fixture 1 .

The slide bar 21 side wall of stage clip one 25 upper positions is provided with a ring outer flange one 29, and the upper end of connecting sleeve 4 is installed on the internal thread in the lower aperture of slide hole 13 by external thread, and the upper end of stage clip one 25 Cooperate with the lower end surface of the outer flange one 29, and cooperate with the upper end surface of the connecting sleeve 4 at the lower end.

An annular outer flange 2 44 is arranged on the outer wall of the connecting sleeve 4 below the lower end surface of the fixing fixture 1, and the outer wall at the opposite position of the outer flange 2 44 is provided with a parallel wrench for installing and dismounting the connecting sleeve 4. Face 45.

The top of the fixed jig 1 hook 12 is provided with an upper pick ring 16 hinged on the hook 12, the jig upper pick ring 16 and the hinge shaft of the hook 12 are provided with one end to match with the jig upper pick ring 16, and the other One end cooperates with the hook 12 to make the torsion spring 17 that the hook 16 extends obliquely above the outside of the hook 12 on the fixture. Pick up the ring 16 on the tool and hold the pick up ring 16 on the fixture so that the pick up ring 16 is folded on the magnet 18 on the hook 12 on the fixture.

The outer wall of the upper end of the control sleeve 5 is provided with a plurality of protrusions 55 that cooperate with the operating rod to pull the control sleeve 5 to make the movable clamp 2 pop up and hold the overhead wire together with the hook 12 of the fixed clamp 1 .

It also includes an operating rod head 7 used in conjunction with it. As shown in Figure 3, the upper half of the operating rod head 7 is a thick tube 71 that can be placed on the outside of the control sleeve 5 from bottom to top, and the lower half is a thick tube that is compatible with the operating rod. Cooperate with the thin tube 72 that can be inserted into the upper end of the operating rod and can support the entire fixture through the control sleeve 5. The thin tube 72 is provided with a through hole that communicates with the inner hole of the thick tube 71 and matches with the lower end of the slide bar 21. The upper end surface of the thick tube 71 is provided with several upward opening grooves 73 corresponding to the positions of the protrusions 55 on the control sleeve 5 one by one. Rotate the operating rod head down to catch the rotation groove 74 of each protrusion 55, and the position between any two open grooves 73 on the upper end of the thick tube 71 is provided with a pull rod connected to the thick tube 71 along the radial direction of the thick tube 71 75, the outer wall of the thick tube 71 at the lower position of the pull rod 75 is provided with a safety hook 76 with one end connected to the outer wall of the thick tube 71 and the other end facing upward. Safety rod 77 on pull bar 75, the other end of safety rod 77 hangs between safety hook 76 gibs and thick tube 71 outer walls and cooperates with safety hook 76 gibs, safety hook 76 gibs are provided with safety rod 77 The lower end of the matching magnet, the safety bar 77 is an iron rod matching with the magnet.

Instructions:

When hanging the ground wire, first insert one end of the ground wire into the ground wire socket 31 on the fixing fixture 1, and press the ground wire on the fixing fixture 1 through two pressing plates 32 and two pressing bolts 33. superior. The movable fixture 2 is pulled away from the fixed fixture 1 to open the opening between the hook 12 and the movable fixture head 22, and the annular steel ball groove 26 on the slide bar 21 retreats to the position matched with each steel ball 42, and the steel ball 42 is retracted into the ring-shaped steel ball groove 26 to eliminate the limiting effect on the control sleeve 5, and the control sleeve 5 is bounced under the action of the compression spring 2 43, and the upper end surface of the control sleeve 5 is pushed against the lower end surface of the outer flange 2 44 of the connecting sleeve 4 superior. The position of the small diameter hole 52 of the control sleeve 5 slides to the matching position with each steel ball hole 41 on the connecting sleeve 4 to limit each steel ball 42 from being bounced outward, and the annular steel ball groove 26 on the slide bar 21 is locked in by each steel ball 42. At the position matched with each steel ball hole 41 on the connection sleeve 4, the movable fixture 2 is locked by the control sleeve 5 and will not be automatically loaded.

Utilize the operating rod head 7 installed on the front end of the operating rod to be placed on the control sleeve 5 from bottom to top, and each opening groove 73 on the thick tube 71 of the operating rod head 7 is matched with each protrusion 55 on the control sleeve 5, and the upper Lift the operating lever to drive the ground wire clamp and ground wire up to the height of the overhead wire, align the opening between the hook 12 and the movable clamp head 22 with the overhead wire and make the overhead wire hanging slot 11 on the hook 12 hang on the overhead wire. superior.

Rotate the operating lever, make the rotating groove 74 on the operating lever head 7 cooperate with each protrusion 55 on the control cover 5 and block each protrusion 55 downwards, pull down the operating lever, the control cover 5 compresses the stage clip 2 43 and slides down, each The steel ball 42 enters the large-diameter hole-51 from the small-diameter hole 52 of the control sleeve 5, and the inner and outer springs no longer play an axial locking effect on the slide bar 21, and the movable fixture 2 can be automatically loaded under the action of the compression spring-25, so that The overhead line clamping groove 23 on the movable fixture head 22 and the overhead line hanging groove 11 on the hook 12 embrace the overhead line together, thereby the grounding line fixture is firmly connected to the overhead line, making the grounding reliable and guaranteed.

After hanging the grounding wire, reverse the operating rod, draw out the operating rod head 7 to disengage the operating rod head 7 from the control sleeve 5, and the operating rod can be separated from the grounding wire clamp and open to the ground.

Utilize the pull bar 75 on the operating rod head 7 to insert the pull ring 24 on the movable fixture head 22 when picking the ground wire, pull down the operating lever, the movable fixture 2 and its slide bar 21 can slide down, and the movable fixture 2 is controlled again The cover 5 is locked and can not be automatically loaded, the ground wire clamp is opened, and the operating lever is picked up, the ground wire clamp can be taken off from the overhead line, and the process of picking the ground wire is completed.

It can be seen from the above-mentioned usage method that this grounding wire clamp is fast, flexible and reliable for hanging and removing the grounding wire, and is very convenient to operate and use.

Claims (10)

1. fast and reliable safety-type grounding wire clamp apparatus, it includes holding clamp（1）And movable fixture（2）, holding clamp（1）On set There is ground wire connecting device（3）, it is characterised in that：Holding clamp（1）Top be provided with side and holding clamp（1）It is linked as one Body, to holding clamp（1）Lower extreme direction be provided with trolley line hanging groove（11）Hook（12）, holding clamp（1）Upper trolley line is hung Groove（11）The relative position in lower section is provided with slide opening along the vertical direction（13）, movable fixture（2）Bottom be arranged on to slide up and down Slide opening（13）Interior slide bar（21）, slide bar（21）Upper end be provided with positioned at slide opening（13）With hook（12）Between movable fixture head （22）, movable fixture head（22）It is provided with upwards and holding clamp（1）On trolley line hanging groove（11）The trolley line of relative engagement Clamping slot（23）, movable fixture head（22）With hook（12）The drawing being engaged with action bars pull bar is provided with the outside of mated position Ring（24）, slide opening（13）Inside it is provided with and is sleeved on slide bar（21）On stage clip one（25）, stage clip（25）Upper end and slide bar（21） Be engaged, lower end and holding clamp（1）It is engaged to movable fixture（2）Form upper elasticity, holding clamp（1）Lower section is provided with upper end With holding clamp（1）Lower end be fixedly linked and slip cap be mounted in slide bar（21）Outside adapter sleeve（4）, holding clamp（1）Under The adapter sleeve of side（4）On the wall of side several steel ball holes are enclosed circumferentially arranged with one（41）, each steel ball hole（41）Inside it is separately installed with one With diameter greater than adapter sleeve（4）The steel ball of sidewall thickness（42）, with adapter sleeve（4）It is provided with steel ball hole（41）Position mutually slide and match somebody with somebody The slide bar of conjunction（21）Outer wall is provided with a circle with each steel ball（42）The annular steel bead groove being engaged（26）, holding clamp（1）Under Side is provided with slip cap mounted in adapter sleeve（4）The control set of outside（5）, control set（5）Upper end endoporus be and each steel ball（42） The large diameter hole one being engaged（51）, large diameter hole one（51）Lower section be and adapter sleeve（4）The minor diameter that outer wall is slidably matched Hole（52）, large diameter hole（51）With small diameter bore（52）Between control set（4）Inwall is the up big and down small guiding conical surface, small Control set below diametric hole（5）Endoporus is that internal diameter is more than small diameter bore（52）Large diameter hole two（53）, large diameter hole two （53）Inside it is provided with and is sleeved on adapter sleeve（4）The stage clip two of outside（43）, adapter sleeve（4）Bottom be provided with outer wall with control cover （5）Large diameter hole two（53）It is slidingly fitted and is fixedly mounted on adapter sleeve（4）End set outside lower end（6）, stage clip two （43）Upper end and large diameter hole two（53）The control set of top（5）Inner face is engaged, lower end covers with end（6）Upper surface phase Coordinate.

2. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 1, it is characterised in that the control set（5）Bottom Side wall be provided with the bar hole of above-below direction（54）, bar hole（54）Inside it is provided with one end and bar hole（54）It is slidably matched, separately One end is radially arranged on end by screw thread and covered（6）On spacing jackscrew（61）, end set（6）Inwall be provided with internal thread, end set （6）Adapter sleeve is arranged on by internal thread（4）On the external screw thread of bottom, end set（6）Lower surface on position diametrically It is respectively provided with installation and removal end set（6）Draw-in groove（62）.

3. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 1, it is characterised in that the ground wire connecting device （3）By located at slide opening（13）Outer holding clamp（1）On the wall of side and downwardly open ground connection line jack（31）, two pieces of tension discs（32） With two line ball bolts（33）Constitute, two line ball bolts（33）Respectively one on the other along ground connection line jack（31）Laterally across It is threadably mounted at holding clamp（1）On the wall of side, two line ball bolts（33）End extend respectively into ground connection line jack（31）It is interior Respectively with two pieces of tension discs（32）It is riveted together and rotates and fits through tension disc（32）Compress ground wire.

4. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 1, it is characterised in that the movable fixture head（22） Towards hook（12）With holding clamp（1）The side being connected is provided with guide runner（27）, holding clamp（1）On along slide opening（13） It is axially arranged with and guide runner（27）The chute being slidingly fitted（14）.

5. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 1, it is characterised in that the hook（12）With fixation Fixture（1）The other end being connected is along perpendicular to trolley line hanging groove（11）Direction be separated at intervals to be provided with and a plurality of extend to hook （12）The bar shaped notch of end（15）, movable fixture head（22）With hook（12）Each bar shaped notch（15）Mated position is provided with It is a plurality of with each bar shaped notch（15）Cooperation is intersected to ensure to trolley line clamping effect and increase movable fixture（2）Slide up and down Some comb of stroke（28）, hook（12）It is provided with bar shaped notch（15）End and movable fixture head（22）It is provided with comb （28）The corresponding position in end there is the arc port for being easy to trolley line to import, draw ring to opposite direction bending respectively（24）It is located at The comb at middle part（28）Lower section is located at movable fixture head（22）Above and positioned at holding clamp（1）Side-wall outer side.

6. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 1, it is characterised in that the stage clip one（25）Top The slide bar of position（21）Side wall is provided with a circle annular external flange one（29）, adapter sleeve（4）Upper end be arranged on by external screw thread Slide opening（13）On the intraoral internal thread of lower opening, stage clip one（25）Upper end and outward flange one（29）Lower surface be engaged, lower end With adapter sleeve（4）Upper surface be engaged.

7. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 1, it is characterised in that described positioned at holding clamp（1） Adapter sleeve below lower surface（4）Outer wall is provided with a circle annular external flange two（44）, outward flange two（44）Outside relative position Wall is provided with and is engaged for mounting and dismounting adapter sleeve with spanner（4）Parallel surface（45）.

8. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 1, it is characterised in that the holding clamp（1）Hook （12）Top be provided with and be hinged on hook（12）On fixture on fetch ring（16）, fetch ring on fixture（16）With hook（12）Be hinged Axle is provided with one end with fetch ring on fixture（16）Be engaged, the other end and hook（12）Being engaged makes fetch ring on fixture（16）To extension Hook（12）The torsion spring that outside oblique upper is stretched（17）, hook（12）It is hinged fetch ring on fixture（16）The top of offside is provided with and is arranged on Hook（12）It is upper to be used to not use fetch ring on fixture（16）When hold fetch ring on fixture（16）Make fetch ring on fixture（16）It is folded in Hook（12）On magnet（18）.

9. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 1, it is characterised in that the control set（5）Upper end Outer wall be provided be engaged with action bars for pull control set（5）Make movable fixture（2）Pop up and holding clamp（1） Hook（12）Hold several projections of trolley line tightly together（55）.

10. fast and reliable safety-type grounding wire clamp apparatus as claimed in claim 9, it is characterised in that it also includes being used in combination Operation head（7）, operate head（7）Upper semisection for can be enclosed within from bottom to top control set（5）Outside thick cylinder（71）, under Half section is to be engaged to be inserted in action bars upper end and can be covered by control with action bars（5）Hold the thin cylinder of whole fixture （72）, thin cylinder（72）Inside it is provided with and thick cylinder（71）Endoporus is communicated and and slide bar（21）The through hole that bottom is engaged, thick cylinder（71） Upper surface is provided with several and is covered with control（5）On each projection（55）The one-to-one upward opening groove in position（73）, respectively open Mouth groove（73）It is circumferentially with for drawing control along identical after extending downwardly one section（5）Operation head can be made card downwards is rotated during set Firmly each projection（55）Swivelling chute（74）, thick cylinder（71）Upper end any two open slot（73）Between position along thick cylinder（71） Be radially provided with one end with thick cylinder（71）Connected pull bar（75）, pull bar（75）The thick cylinder of lower position（71）Outer wall is provided with one End and thick cylinder（71）Outer wall is connected, the auxiliary catch of other end crotch upward（76）, pull bar（75）Middle part and auxiliary catch（76）Gib head Corresponding position is provided with one end and is hinged on pull bar（75）On bumper bar（77）, bumper bar（77）The other end overhang insurance Hook（76）Gib head and thick cylinder（71）With auxiliary catch between outer wall（76）Gib head is engaged, auxiliary catch（76）Gib head is provided with and insurance Bar（77）The magnet that is engaged of bottom, bumper bar（77）It is the iron being engaged with magnet.