CN208686434U

CN208686434U - A kind of coal mine down-hole tunnel driving measuring device

Info

Publication number: CN208686434U
Application number: CN201821499265.0U
Authority: CN
Inventors: 范发龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-09-13
Filing date: 2018-09-13
Publication date: 2019-04-02
Anticipated expiration: 2028-09-13

Abstract

The utility model discloses a kind of coal mine down-hole tunnels of measuring device technical field to tunnel measuring device, including pedestal, the horizontal trishores top of the trellis is provided with adjusting rod, the rotation shaft rear end is on rear side of arc groove and is socketed with drive roll, Measuring plate is movably set with by pin shaft on the right side of the mounting plate rear end, the drive roll, driven voller and live-roller are sequentially connected by driving belt, this is novel when tunnelling machine works forward, stress spring contacts measurement idler wheel with back always, to rotate, drive roll is driven when measurement idler wheel rotation, drive roll drives driven voller and live-roller to rotate by driving belt, driven voller has driven pin shaft rotation when rotating, pin shaft rotation drives indicators turn, according to the scale strip of the circle number combination disk body of indicators turn carry out calculate can calculate driving tunnel it is long Degree does not need fixed cotton rope and calculates, simple and convenient, nor affects on drivage efficiency.

Description

A kind of coal mine down-hole tunnel driving measuring device

Technical field

The utility model relates to measuring device technical field, specially a kind of coal mine down-hole tunnel tunnels measuring device.

Background technique

Coal mine is the proportional space that the mankind are excavated when digging is rich in the geological stratification for having coal, generally includes tunnel, well Cave and face etc., if coal mine tunnel top board displacement is larger, drastically influence coal mine operation in entry Safety is carried out, and especially during headwork is pushed ahead, in existing roadway roof displacement measurement, mostly uses artificial survey Amount uses traditional measurement mode (such as artificial measuring tape, the online tether of anchor, tunnel roof and floor convergence gauge, multiple spot at regular intervals Displacement meter etc.) roadway roof displacement is measured, not only required labour is larger for this kind of mode, and measurement is not accurate, and cannot It matches, and the single tunnel length that cannot measure driving well of existing measuring device structure, digs with headwork Into tunnel length computation be related to the laying work of subsequent underground coal mine conducting wire, generally requiring the later period passes through manual operation and surveys Amount equipment is calculated, and in order to fix cotton rope during measurement, construction team's group needs to stop excavation operation and pushing up Plate perforating and insertion timber wedge, thus influence drivage efficiency, for this purpose, it is proposed that a kind of coal mine down-hole tunnel tunnels measuring device.

Summary of the invention

The purpose of this utility model is to provide a kind of coal mine down-hole tunnels to tunnel measuring device, to solve above-mentioned background skill The problem of being proposed in art.

To achieve the above object, the utility model provides the following technical solutions: a kind of coal mine down-hole tunnel driving measurement dress It sets, including pedestal, the base top is provided with horizontal three-legged supporting frame, and the horizontal trishores top of the trellis is provided with adjusting Bar, the adjusting rod left side are fixedly installed fixed link, are plugged with motion bar at the top of the fixed link, the motion bar bottom end is passed through It fastens at the top of fixed pole and is fixedly connected by stress spring with bottom of fixed inner wall, the motion bar top is connected with connection Block, the link block top offers arc groove, and measurement idler wheel is provided in arc groove, the measurement idler wheel the center point Front and back is plugged with rotation axis, and the rotation axis front end is connect by bearing with arc groove front inner wall, the rotation shaft rear end On rear side of arc groove and it is socketed with drive roll, the horizontal three-legged supporting frame top vertical is provided with guide rod, and is oriented to Bar is located on the left of fixed link, and the fixed link left bottom outer wall is provided with sliding block, and guide rod outer right wall is offered and slided The sliding slot of Block- matching, the fixed link rear side outer wall are fixedly installed mounting plate, are lived on the right side of the mounting plate rear end by pin shaft It is dynamic to be provided with Measuring plate, and pin shaft outer wall is socketed with driven voller, laterally offers dovetail chute on the left of the mounting plate rear end, institute The dovetail slide block for being provided with and matching in dovetail chute is stated, is connected with mounting rod, and mounting rod outer wall on rear side of the dovetail slide block It is socketed with live-roller, the drive roll, driven voller and live-roller are sequentially connected by driving belt, in the dovetail chute right side Wall is fixedly installed compensation bar, and the compensation bar left end is plugged with push rod, and push rod right end through compensation bar left end and is connected with Reset spring, and push rod right end is fixedly connected by reset spring with inner wall on the right side of compensation bar, and the push rod other end and mounting rod Outer wall connection.

Preferably, the horizontal three-legged supporting frame includes the horizontal ball connecting with adjusting rod bottom, the horizontal ball outer wall It is socketed with shell, the inner walls are evenly arranged with ball pocket, and are provided in ball pocket and turn ball, and turn ball and horizontal ball surface patch It closes, the housing bottom center offers port, and port bottom is provided with installing pipe, and the surface of shell equidistantly rotates connection There is the identical strut of three groups of structures, strut bottom described in three groups is plugged with buffer bar, and buffer bar outer wall is socketed with buffering elastic Spring, base top front and back side is disposed with three groups of fixed blocks from left to right, and is plugged with connection before and after buffer bar bottom Axis, and connecting shaft front end through front side fixed block and is socketed with nut, and connects shaft rear end through rear side fixed block and be socketed with Nut, the bottom center location of the horizontal ball is equipped with counterweight column straight down, and counterweight column through installing pipe and is connected with Clump weight.

Preferably, the horizontal ball is hemispherical horizontal ball, and the shell is hemispherical shell, and the clump weight is to stand upside down Conical clump weight, the installing pipe lower end diameter is less than installing pipe upper end diameter, and installing pipe upper end diameter and port are straight Diameter is identical.

Preferably, the adjusting rod includes the turntable connecting with horizontal trishores top of the trellis, a left side for the turntable bottom Right two sides are provided with sphere, and horizontal ball top right side is provided with and the matched annular ball pocket of sphere, turntable top welding There is screw rod, and screw rod outer wall is socketed with connecting rod, and welds on the left of connecting rod on the right side of fixed link, the connecting rod bottom opens up Have and the matched threaded hole of screw rod.

Preferably, the Measuring plate includes the connection bearing for being fixedly attached to pin shaft outer wall, outside the connection bearing circumference Wall is socketed with disk body, and pin shaft rear end is provided with pointer, and the pointer rear end is provided with threaded rod, and pin shaft rear end offer with The matched threaded connection hole of threaded rod, the disk body rear side outer circumferential walls are provided with scale strip.

Preferably, the disk body the center point offers and connect the matched circular through hole of bearing, and at the top of circular through hole and Bottom symmetrical is provided with the identical arc fixture block of structure, and arc fixture block is elastic rubber fixture block, and is connected at the top of bearing outer wall It is opened up and the matched arc-shaped slot of arc fixture block with bottom symmetrical.

Preferably, the adjusting rod, motion bar and guide rod front outer wall are provided with scale strip, the base top four Zhou Jun, which is plugged with, is bolted bar.

Compared with prior art, the utility model has the beneficial effects that

Screw rod is rotated 1. the utility model passes through rotation turntable when in use, makes connecting rod that fixed link be driven to rise, when When measurement idler wheel and back contact, calculated by the scale strip of record adjusting rod, motion bar and guide rod front outer wall Length between horizontal ball and back is recorded, when tunnelling machine works forward, when back portion goes out Idler wheel can be made to measure when now deviating, and to push motion bar extrusion stress spring downward, just further according to adjusting rod, motion bar and guide rod The scale strip of face outer wall calculates the length between horizontal ball and back, by this record result and preceding one-shot measurement As a result it compares the distance that can determine roadway roof displacement, reduces labour, and be provided with horizontal three-legged supporting frame, level three Clump weight on foot support frame is always ensured that horizontal ball is in horizontal line, while being provided with buffer spring and buffer bar, can be effective Reduction tunnelling machine forward headwork when the vibration that occurs and top measuring device is caused one high and one low situation occur, Guarantee the precision of measurement.

2. the utility model, when tunnelling machine works forward, stress spring connects measurement idler wheel with back always Touching, to rotate when tunnelling machine tunnels forward, when measurement idler wheel rotation, drives rotation axis rotation, rotation axis to Drive roll is driven, drive roll drives driven voller and live-roller to rotate by driving belt, and driven voller has driven pin shaft to turn when rotating Dynamic, pin shaft rotation drives indicators turn, and calculate according to the scale strip of the circle number combination disk body of indicators turn can calculate The tunnel length of driving, while it being provided with compensation bar, reset spring and push rod cooperation, when motion bar is downward, at this point, transmission skin Band is in loosening state, and reset spring pushes dynamic push rod again at this time moves dovetail slide block in dovetail chute, to make to be driven Roller tight contacts between driving belt, and driving belt is made to be in tensioned state, and guarantee is normally carried out transmission work, does not need fixed cotton rope It calculates, it is simple and convenient, nor affect on drivage efficiency.

Detailed description of the invention

FIG. 1 is a schematic structural view of the utility model；

Fig. 2 is the utility model live-roller the structure left view；

Fig. 3 is the utility model mounting plates structure rearview；

Fig. 4 is the utility model adjusting rod structural schematic diagram.

In figure: 1 pedestal, 2 horizontal three-legged supporting frames, 21 horizontal balls, 22 shells, 23 turns of balls, 24 struts, 25 installing pipes, 26 Counterweight column, 27 clump weights, 28 buffer springs, 3 adjusting rods, 31 turntables, 32 spheres, 33 screw rods, 34 connecting rods, 4 fixed links, 5 are lived Lever, 6 link blocks, 7 measurement idler wheels, 8 rotation axis, 9 guide rods, 10 mounting plates, 11 drive rolls, 12 driving belts, 13 Measuring plates, 131 connection bearings, 132 disk bodies, 133 pointers, 14 dovetail chutes, 15 compensation bars, 16 live-rollers, 17 dovetail slide blocks, 18 pin shafts.

Specific embodiment

The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work Every other embodiment obtained, fall within the protection scope of the utility model.

Fig. 1-4 is please referred to, the utility model provides a kind of technical solution: a kind of coal mine down-hole tunnel driving measuring device, Including pedestal 1, pedestal 1 is provided with horizontal trishores for the measuring device to be connected with tunnelling machine at the top of pedestal 1 Frame 2 provides support, guarantees that levelness when measurement improves measurement accuracy, is provided with adjusting rod 3 at the top of horizontal three-legged supporting frame 2, The adjusting work of height is carried out according to back, is fixedly installed fixed link 4 on the left of adjusting rod 3, is plugged at the top of fixed link 4 Motion bar 5,5 bottom end of motion bar with fixed link 4 bottom interior wall are fixedly connected through 4 top of fixed link and by stress spring, are made The measurement idler wheel 7 at top is contacted with back always, and 5 top of motion bar is connected with link block 6, is offered at the top of link block 6 Arc groove, and measurement idler wheel 7 is provided in arc groove, subsidiary tunnel length, measurement 7 the center point of idler wheel front and back grafting There is rotation axis 8,8 front end of rotation axis is connect by bearing with arc groove front inner wall, after arc groove is run through in 8 rear end of rotation axis Side is simultaneously socketed with drive roll 11, and horizontal 2 top vertical of three-legged supporting frame is provided with guide rod 9, and guide rod 9 is located at fixed link 4 Left side, 4 left bottom outer wall of fixed link is provided with sliding block, and 9 outer right wall of guide rod offers and the matched sliding slot of sliding block, cunning Block and sliding slot match the stability not only improved when adjusting height, while can also make 33 turns of screw rod to avoid in rotation turntable 31 When dynamic, screw rod 33 drives connecting rod 34 to rotate, and 4 rear side outer wall of fixed link is fixedly installed mounting plate 10, for installing measurement lane Structure required for road length, 10 rear end of mounting plate right side are movably set with Measuring plate 13 by pin shaft 18, measure in order to prevent Disk 13 is driven by pin shaft 18 and rotates, and can pass through on rear side of bracket and mounting plate 10 on front side of Measuring plate 13 and be fixedly connected, and pin shaft 18 outer walls are socketed with driven voller, laterally offer dovetail chute 14 on the left of 10 rear end of mounting plate, are provided with phase in dovetail chute 14 Matched dovetail slide block 17, moves live-roller 16, mounting rod is connected on rear side of dovetail slide block 17, and outside mounting rod Wall is socketed with live-roller 16, and drive roll 11, driven voller and live-roller 16 are sequentially connected by driving belt 12, are driven in order to prevent Belt 12 is detached from drive roll 11, driven voller and live-roller 16, can be offered on drive roll 11, driven voller and live-roller 16 with The matched annular groove of driving belt 12,14 right side inner wall of dovetail chute are fixedly installed compensation bar 15, and compensation 15 left end of bar is inserted Be connected to push rod, and push rod right end through compensation 15 left end of bar and is connected with reset spring, and push rod right end by reset spring with Compensation 15 right side inner wall of bar is fixedly connected, and the push rod other end is connect with mounting rod outer wall, when motion bar 5 is downward, at this point, passing Dynamic belt 12 is in loosening state, and reset spring pushes dynamic push rod again at this time makes live-roller 16 tight contact between driving belt 12, makes Driving belt 12 is in tensioned state, to be normally carried out transmission work.

Wherein, horizontal three-legged supporting frame 2 includes the horizontal ball 21 connecting with 3 bottom of adjusting rod, the socket of 21 outer wall of horizontal ball There is shell 22,22 inner wall of shell is evenly arranged with ball pocket, and is provided in ball pocket and turns ball 23, and turns ball 23 and 21 surface of horizontal ball Fitting, reduces frictional force of the horizontal ball 21 in tumbling motion, 22 bottom center of shell offers port, and port bottom is set It is equipped with installing pipe 25,22 surface of shell, which equidistantly rotates, is connected with the identical strut 24 of three groups of structures, is supported, three groups of struts 24 Bottom is plugged with buffer bar, and buffer bar outer wall is socketed with buffer spring 28, inevitably can when tunnelling machine is worked Vibration is generated, influence of the vibration to measuring device is reduced, 1 top front and back side of pedestal is disposed with three groups from left to right and fixes Block, and connecting shaft is plugged with before and after buffer bar bottom, and connecting shaft front end through front side fixed block and is socketed with nut, and connects Shaft rear end is through rear side fixed block and is socketed with nut, and convenient for adjusting angle, the bottom center location of horizontal ball 21 is straight down Counterweight column 26 is installed, and counterweight column 26 through installing pipe 25 and is connected with clump weight 27, horizontal ball 21 is made to remain horizontal State, to improve measurement accuracy；

Horizontal ball 21 is hemispherical horizontal ball, and shell 22 is hemispherical shell, and clump weight 27 is the conical counterweight stood upside down Block provides good gravity downward vertically, and 25 lower end diameter of installing pipe is less than 25 upper end diameter of installing pipe, and in installing pipe 25 It holds diameter identical as port diameter, prevents counterweight column 26 from swinging；

Adjusting rod 3 includes and the turntable 31 that connects at the top of horizontal three-legged supporting frame 2, the left and right sides setting of 31 bottom of turntable There is sphere 32, and 21 top right side of horizontal ball is provided with and is simultaneously convenient for the rotation of turntable 31 with the matched annular ball pocket of sphere 32 It is used convenient for operator, anti-skid chequer can be opened up in 31 outer wall of turntable, screw rod 33, and screw rod 33 are welded at the top of turntable 31 Outer wall is socketed with connecting rod 34, convenient for adjusting connecting rod 34, rises or falls, and the left side of connecting rod 34 with welded on the right side of fixed link 4 It connects, 34 bottom of connecting rod offers and the matched threaded hole of screw rod 33；

Measuring plate 13 includes the connection bearing 131 for being fixedly attached to 18 outer wall of pin shaft, that is, the inner ring of connection bearing 131 It is fixedly connected with 18 outer wall of pin shaft, so that pin shaft 18 is avoided result in disk body 132 when rotating and also and then rotate, connect 131 circumference of bearing Outer wall is socketed with disk body 132, and 18 rear end of pin shaft is provided with pointer 133, and 133 rear end of pointer is provided with threaded rod, and pin shaft 18 Rear end offer with the matched threaded connection hole of threaded rod, installation easy to disassemble, 132 rear side outer circumferential walls of disk body are provided with scale Item, the circle number combination scale strip convenient for being rotated by pointer 133 carry out calculating tunnel length；

132 the center point of disk body offers and connect the matched circular through hole of bearing 131, and right at the top and bottom of circular through hole Title is provided with the identical arc fixture block of structure, and arc fixture block is elastic rubber fixture block, and connects 131 outer wall of bearing top and bottom Portion symmetrically opens up and the matched arc-shaped slot of arc fixture block, the different Measuring plate 13 of installation easy to disassemble；

Adjusting rod 3, motion bar 5 and 9 front outer wall of guide rod are provided with scale strip, convenient for calculating at the top of tunnel to level The distance between ball 21 compares the result of result and preceding one-shot measurement at a distance from determining roadway roof displacement, 1 top of pedestal Surrounding is plugged with and is bolted bar, for the measuring device to be connected with tunnelling machine.

Working principle: in use, being bolted bar by surrounding is mounted on suitable position on tunnelling machine for the device It sets, rotates screw rod 33 by rotating turntable 31, to make connecting rod 34 that fixed link 4 be driven to rise, when measurement idler wheel 7 and tunnel When top plate contact, adjusting rod 3 is recorded first, the scale strip of 9 front outer wall of motion bar 5 and guide rod calculates horizontal ball 21 Length between back is recorded, when tunnelling machine works forward, when back portion deviates When can make to measure idler wheel 7, and to push 5 extrusion stress spring of motion bar downward, further according to 9 front of adjusting rod 3, motion bar 5 and guide rod The scale strip of outer wall calculates the length between horizontal ball 21 and back, by this record result and preceding one-shot measurement As a result it compares the distance that can determine roadway roof displacement, while when tunnelling machine works forward, measures idler wheel 7 and lane Road top plate contact, rotates, and measurement idler wheel 7 drives rotation axis 8 to rotate when rotating, and rotation axis 8 is main to drive drive roll 11 Dynamic roller 11 drives driven voller and live-roller 16 to rotate by driving belt 12, and driven voller has driven pin shaft 18 to rotate when rotating, pin The rotation of axis 18 drives pointer 133 to rotate, and the scale strip of the circle number combination disk body 132 rotated according to pointer 133 is calculated The tunnel length of driving is calculated, while being provided with compensation bar 15, reset spring and push rod cooperation, when motion bar 5 is downward, this When, driving belt 12 is in loosening state, and reset spring pushes dynamic push rod again at this time makes dovetail slide block 17 in dovetail chute 14 It is mobile, so that live-roller 16 be made to tight contact between driving belt 12, driving belt 12 is made to be in tensioned state, is passed to be normally carried out It starts building to make.

While there has been shown and described that the embodiments of the present invention, for the ordinary skill in the art, It is understood that these embodiments can be carried out with a variety of variations in the case where not departing from the principles of the present invention and spirit, repaired Change, replacement and variant, the scope of the utility model is defined by the appended claims and the equivalents thereof.

Claims

1. a kind of coal mine down-hole tunnel tunnels measuring device, including pedestal (1), it is characterised in that: setting at the top of the pedestal (1) Have horizontal three-legged supporting frame (2), is provided with adjusting rod (3) at the top of the horizontal three-legged supporting frame (2), the adjusting rod (3) is left Side is fixedly installed fixed link (4), is plugged with motion bar (5) at the top of the fixed link (4), motion bar (5) bottom end is run through It is fixedly connected at the top of fixed link (4) and by stress spring with fixed link (4) bottom interior wall, motion bar (5) the top connection Have link block (6), offer arc groove at the top of the link block (6), and is provided with measurement idler wheel (7), institute in arc groove It states measurement idler wheel (7) the center point front and back to be plugged with rotation axis (8), before rotation axis (8) front end is by bearing and arc groove The connection of side inner wall, rotation axis (8) rear end is on rear side of arc groove and is socketed with drive roll (11), the three foot branch of level Support (2) top vertical is provided with guide rod (9), and guide rod (9) is located on the left of fixed link (4), on the left of the fixed link (4) Bottom outer wall is provided with sliding block, and guide rod (9) outer right wall offer with the matched sliding slot of sliding block, after the fixed link (4) Side outer wall is fixedly installed mounting plate (10), is movably set with Measuring plate by pin shaft (18) on the right side of mounting plate (10) rear end (13), and pin shaft (18) outer wall is socketed with driven voller, laterally offers dovetail chute (14) on the left of mounting plate (10) rear end, It is provided with the dovetail slide block (17) to match in the dovetail chute (14), is connected with installation on rear side of the dovetail slide block (17) Bar, and mounting rod outer wall is socketed with live-roller (16), the drive roll (11), driven voller and live-roller (16) pass through driving belt (12) it is sequentially connected, inner wall is fixedly installed compensation bar (15), compensation bar (15) left end on the right side of the dovetail chute (14) It is plugged with push rod, and push rod right end through compensation bar (15) left end and is connected with reset spring, and push rod right end is by resetting bullet Spring is fixedly connected with inner wall on the right side of compensation bar (15), and the push rod other end is connect with mounting rod outer wall.

2. a kind of coal mine down-hole tunnel according to claim 1 tunnels measuring device, it is characterised in that: three foot of level Support frame (2) includes the horizontal ball (21) connecting with adjusting rod (3) bottom, and horizontal ball (21) outer wall is socketed with shell (22), shell (22) inner wall is evenly arranged with ball pocket, and is provided in ball pocket and turns ball (23), and turn ball (23) and horizontal ball (21) surface is bonded, and shell (22) bottom center offers port, and port bottom is provided with installing pipe (25), the shell Body (22) surface, which equidistantly rotates, is connected with the identical strut (24) of three groups of structures, and strut described in three groups (24) bottom is plugged with slow Jumper bar, and buffer bar outer wall is socketed with buffer spring (28), front and back side is disposed with three from left to right at the top of the pedestal (1) Group fixed block, and connecting shaft is plugged with before and after buffer bar bottom, and connecting shaft front end through front side fixed block and is socketed with nut, And connection shaft rear end through rear side fixed block and is socketed with nut, the bottom center location of the horizontal ball (21) is pacified straight down Equipped with counterweight column (26), and counterweight column (26) through installing pipe (25) and is connected with clump weight (27).

3. a kind of coal mine down-hole tunnel according to claim 2 tunnels measuring device, it is characterised in that: the horizontal ball It (21) is hemispherical horizontal ball, the shell (22) is hemispherical shell, and the clump weight (27) is the conical counterweight stood upside down Block, installing pipe (25) lower end diameter is less than installing pipe (25) upper end diameter, and installing pipe (25) upper end diameter and port are straight Diameter is identical.

4. a kind of coal mine down-hole tunnel according to claim 1 or 2 tunnels measuring device, it is characterised in that: the adjusting Bar (3) includes the turntable (31) connecting with horizontal three-legged supporting frame (2) top, the left and right sides setting of turntable (31) bottom Have sphere (32), and horizontal ball (21) top right side is provided with and sphere (32) matched annular ball pocket, turntable (31) top Portion is welded with screw rod (33), and screw rod (33) outer wall is socketed with connecting rod (34), and right with fixed link (4) on the left of connecting rod (34) Side welding, connecting rod (34) bottom offer and screw rod (33) matched threaded hole.

5. a kind of coal mine down-hole tunnel according to claim 1 tunnels measuring device, it is characterised in that: the Measuring plate It (13) include the connection bearing (131) for being fixedly attached to pin shaft (18) outer wall, connection bearing (131) outer circumferential walls are socketed with Disk body (132), and pin shaft (18) rear end is provided with pointer (133), pointer (133) rear end is provided with threaded rod, and pin shaft (18) rear end, which is offered, is provided with scale strip with the matched threaded connection hole of threaded rod, disk body (132) the rear side outer circumferential walls.

6. a kind of coal mine down-hole tunnel according to claim 5 tunnels measuring device, it is characterised in that: the disk body (132) the center point offers and connect bearing (131) matched circular through hole, and is symmetrically arranged at the top and bottom of circular through hole The identical arc fixture block of structure, and arc fixture block is elastic rubber fixture block, and is connected symmetrical at the top and bottom of bearing (131) outer wall It opens up and the matched arc-shaped slot of arc fixture block.

7. a kind of coal mine down-hole tunnel according to claim 1 tunnels measuring device, it is characterised in that: the adjusting rod (3), motion bar (5) and guide rod (9) front outer wall are provided with scale strip, and surrounding is plugged with spiral shell at the top of the pedestal (1) Tether extension bar.