CN110961235A

CN110961235A - Cutting bits recovery processing device

Info

Publication number: CN110961235A
Application number: CN201911197381.6A
Authority: CN
Inventors: 靳刚; 张鑫雨; 刘浩; 李占杰; 崔良玉; 胡高峰; 韩建鑫; 戚厚军
Original assignee: Tianjin University of Technology and Education China Vocational Training Instructor Training Center
Current assignee: Dragon Totem Technology Hefei Co ltd
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2020-04-07
Anticipated expiration: 2039-11-29
Also published as: CN110961235B

Abstract

The invention relates to a cutting chip recovery processing device, which effectively solves the problems that the existing long and winding cutting chips are low in manual dispersion efficiency and high in difficulty before being crushed, and workers are easy to be injured; the technical scheme of its solution includes the workstation, a backup pad is respectively installed to both sides around the workstation, the top of workstation intermediate position is equipped with a plastic chamber, the left side of plastic chamber is around spaced arrangement side by side two slopes and can be synchronous inside pivoted first licker-in, the below of two first licker-in is equipped with the conveyer belt, the outside of every backup pad is equipped with a montant, two montants can be synchronous in opposite directions or dorsad motion, the inboard of every montant has a plurality of horizontal poles along montant length direction interval equipartition, two montant opposite directions motion can make a plurality of horizontal poles insert to two backup pads inboards and form the grid with plastic chamber right side opening shutoff, the right side of horizontal pole is equipped with a second licker-in of arranging between two backup pads in, be equipped with the cutter that can launch downwards between second licker-in and the horizontal pole.

Description

Cutting bits recovery processing device

Technical Field

The invention relates to the field of recovery of machining waste, in particular to a cutting chip recovery and treatment device.

Background

The cutting chip crushing machine has the advantages that a large amount of cutting chips can be generated in the mechanical machining process, the types of the cutting chips are various, the cutting chips are long, short, strip-shaped, arc-shaped, winding-shaped and the like, the short cutting chips can be directly pressed into cakes through deoiling after being recovered, and then the cakes are convenient to transport and return to a furnace, the cutting chips in the long strip shape and the winding shape need to be crushed before the cakes are pressed, but a large amount of winding-shaped cutting chips can be mutually hooked when the cutting chips are thrown to the crusher, so that the crusher is excessively fed once, the crusher is overloaded, the crushing effect is poor, the winding-shaped cutting chips need to be manually dispersed before being crushed, the phenomenon that workers are cut in the manual dispersion process is frequently generated, meanwhile, the manual dispersion efficiency is low, and the dispersion difficulty is large.

Disclosure of Invention

Aiming at the situation, the invention provides a cutting chip recovery processing device for overcoming the defects of the prior art, and effectively solves the problems that the existing long and winding cutting chips are low in manual dispersion efficiency and high in difficulty before being crushed, and workers are easy to be injured.

The technical scheme includes that the device comprises a horizontal workbench, a vertical support plate is respectively arranged on the front side and the rear side of the workbench, a horizontal transverse plate is arranged above the middle position of the workbench, two ends of the horizontal transverse plate are respectively fixed on the two support plates, the transverse plate, the workbench and the two support plates form a shaping cavity with openings at the left end and the right end, two first licker-in rollers capable of synchronously rotating inwards are arranged on the front side and the rear side of the left side of the shaping cavity at intervals, the left ends of the two first licker-in rollers are obliquely arranged upwards, a conveying belt arranged on the workbench is arranged below the two first licker-in rollers, a vertical rod is arranged on the outer side of each support plate, the two vertical rods can synchronously move towards or away from each other, a plurality of cross rods are uniformly distributed on the inner side of each vertical rod along the length direction of the vertical rod at intervals, the two vertical rods, two montants move dorsad to the grid and begin to rotate with the conveyer belt when will putting shape chamber right-hand member opening and open completely, the right side of horizontal pole is equipped with a second licker-in of arranging between two backup pads in, two montants move in opposite directions and second licker-in begins to rotate when grid will put shape chamber right-hand member opening and seal completely, be equipped with a cutter that can launch downwards between second licker-in and the horizontal pole, the cutter top is equipped with chucking mechanism, the drive cutter rebound is and is blocked the chucking of chucking mechanism when the montant outwards removes, can drive chucking mechanism after the second licker-in rotates and loosen the cutter and launch downwards.

The invention has novel conception, smart structure and strong practicability, and effectively solves the problems of low manual dispersion efficiency, high difficulty and easy injury of workers of the existing long and winding cutting chips before crushing.

Drawings

FIG. 1 is a top view of the present invention.

FIG. 2 is a front sectional view of the present invention.

FIG. 3 is an enlarged view of a portion of the area A in FIG. 2 according to the present invention.

Fig. 4 is a front view of the present invention.

FIG. 5 is a right side sectional view of the present invention showing the vertical post and its driving and accessory devices.

Fig. 6 is a right side view showing the cutter 9 chucking mechanism and its driving means of the present invention.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

As can be seen from the drawings from 1 to 6, the invention comprises a horizontal workbench 1, wherein the front side and the rear side of the workbench 1 are respectively provided with a vertical support plate 2, a horizontal transverse plate 3 with two ends respectively fixed on the two support plates 2 is arranged above the middle position of the workbench 1, the transverse plate 3, the workbench 1 and the two support plates 2 form a shaping cavity with openings at the left end and the right end, two first licker-in rollers 4 capable of synchronously rotating inwards are arranged at the front side and the rear side of the left side of the shaping cavity at intervals, the left ends of the two first licker-in rollers 4 are obliquely arranged upwards, a conveyor belt 5 arranged on the workbench 1 is arranged below the two first licker-in rollers 4, the outer side of each support plate 2 is provided with a vertical rod 6, the two vertical rods 6 can synchronously move oppositely or reversely, a plurality of cross rods 7 are uniformly distributed at intervals along the length direction of the vertical rods 6 on the inner side of each vertical rod 6, the two vertical rods 6 move oppositely, the plurality of cross rods, two montant 6 move in opposite directions to the grid two first licker-in 4 and conveyer belt 5 begin to rotate when will putting shape chamber right-hand member opening and open completely, the right side of horizontal pole 7 is equipped with one and arranges second licker-in 8 between two backup pads 2 in, two montant 6 move in opposite directions to the grid when will putting shape chamber right-hand member opening and close completely second licker-in 8 begins to rotate, be equipped with a cutter 9 that can launch downwards between second licker-in 8 and the horizontal pole 7, cutter 9 top is equipped with chucking mechanism, drive cutter 9 rebound and by chucking mechanism chucking when montant 6 outwards removes, can drive chucking mechanism after second licker-in 8 rotates and loosen cutter 9 and launch downwards.

In order to realize timely clearance of first licker-in 4 and 8 outer fringe faces of second licker-in, every first licker-in 4's the outside is equipped with one and arranges first arc scraper blade 10 of first licker-in 4 below in, the intrados of first arc scraper blade 10 is laminated with the roll surface of first licker-in 4 mutually, the corresponding tip of first arc scraper blade 10 and first licker-in 4 roller thorn is equipped with a plurality of logical grooves that supply the roller thorn to pass through, the right side of second licker-in 8 is equipped with one and arranges second arc scraper blade 11 of second licker-in 8 below in, the intrados of second arc scraper blade 11 is laminated with the roll surface of second licker-in 8 mutually, the corresponding tip of second arc scraper blade 11 and second licker-in 8 roller thorn is equipped with a plurality of logical grooves that supply the roller thorn to pass through.

In order that the two first licker-in rollers 4 can synchronously rotate inwards, a first gear 12 is coaxially fixed on a mandrel at the left end of each first licker-in roller 4, the two first gears 12 are mutually meshed, a first belt pulley 13 is also coaxially fixed on a mandrel of one first licker-in roller 4, a second belt pulley 14 driven by a first motor is arranged on the outer side of the supporting plate 2, and the first belt pulley 13 is connected with the second belt pulley 14 through a belt.

In order to realize the synchronous opposite or back-to-back movement of the two vertical plates, two electric push rods 15 which correspond to the two vertical rods 6 one to one are arranged below the workbench 1, the vertical rods 6 are respectively arranged at the extending ends of the electric push rods 15 corresponding to the vertical rods 6, and the two electric push rods 15 can synchronously move inwards or outwards.

In order to realize that the vertical rod 6 moves outwards to the farthest distance, the first licker-in 4 and the conveyor belt 5 rotate, the second licker-in 8 starts to rotate when the vertical rod 6 moves inwards to the nearest distance, the lower end of the rear side vertical rod 6 is provided with an L-shaped pressure lever 16 arranged below the electric push rod 15, the rear end of the rear side electric push rod 15 is provided with a first contact switch 17 of a first motor and a drive motor of the conveyor belt 5, the second licker-in 8 is driven by a second motor, the front end of the rear side electric push rod 15 is provided with a second contact switch 18 of the second motor, the pressure lever 16 contacts and extrudes the first contact switch 17 when the rear side vertical plate moves outwards to the farthest position, and the pressure lever 16 contacts and extrudes the second contact switch 18 when the rear side vertical plate moves inwards to the nearest position.

When moving to the outside in order to realize montant 6, cutter 9 moves upward and is blocked the chucking of clamping mechanism, the top of cutter 9 is equipped with a opening casing 19 down, casing 19 bottom is equipped with a plurality of first pressure springs 20, the one end of first pressure spring 20 is fixed in casing 19 bottom, the other end is fixed on cutter 9, be equipped with a first rope 21 on every montant 6, the outside of every backup pad 2 is fixed with a first fixed pulley 22 through branch, the top of every backup pad 2 is equipped with a second fixed pulley 23, the first rope 21 free end of homonymy is walked around first fixed pulley 22 in proper order, penetrate casing 19 and fix on cutter 9 from casing 19 bottom behind the second fixed pulley 23.

In order to realize that the clamping mechanism loosens the cutter 9 after the second licker-in 8 rotates, the clamping mechanism comprises two groups of clamping mechanisms which are respectively arranged at the front side and the rear side of the right side wall of the shell 19, the clamping mechanism comprises a sleeve 24 with the right end closed and the left end communicated with the shell 19, a wedge block 25 is arranged in the sleeve 24, the wedge surface of the wedge block 25 faces towards the left lower end, a clamping groove 26 matched with the wedge block 25 is arranged on the cutter 9, a second pressure spring 27 is arranged at the bottom of the sleeve 24, one end of the second pressure spring 27 is fixed at the bottom of the sleeve 24, the other end of the second pressure spring is fixed on the wedge block 25, two first friction wheels 28 which are arranged outside the supporting plate 2 are respectively fixed at two ends of a mandrel of the second licker-in 8, a second friction wheel 29 which can be contacted and driven by an outer circular surface is arranged at the outer side of each first friction wheel 28, an arc bulge 30 is arranged on the outer end surface, an L-shaped rod 31 is arranged on the outer side of each second friction wheel 29, the end of a cross rod 7 of each L-shaped rod 31 is arranged on the outer side of each second friction wheel 29, the end of a vertical rod penetrates through and extends into the corresponding side supporting plate 2, a third pressure spring 32 capable of enabling the pull rod to move inwards is arranged on the part, arranged in the supporting plate 2, of each L-shaped rod 31, a second rope 33 is fixed at one end, arranged in the supporting plate 2, of each L-shaped rod 31, the other end of each second rope 33 penetrates through the bottom of the corresponding side sleeve 24 to be connected with the wedge block 25, and the arc-shaped protrusions 30 on the second friction wheels 29 extrude the L-shaped rods 31 to enable the second ropes 33 to be tightened and pull the wedge blocks 25.

The specific working process of the invention is as follows: the device is placed at the feeding position of a crusher, materials discharged from the right end of a workbench 1 enter a crusher feed hopper, large lumps of cutting chips to be dispersed are placed at the left end of a conveyor belt 5, an electric push rod 15 is opened at the moment to enable the two electric push rods 15 to synchronously move outwards, the electric push rod 15 drives a vertical rod 6 to move outwards in the outwards moving process at the moment, the vertical rod 6 drives a plurality of cross rods 7 to move outwards in the outwards moving process, a grid formed by the cross rods 7 is opened at the moment, meanwhile, in the outwards moving process of the vertical rods 6 at two sides, a first rope 21 is tightened, in the tightening process of the first rope 21, the cutter 9 is lifted upwards through a first fixed pulley 22 and a second fixed pulley 23, in the upwards lifting process of the cutter 9, the first pressure spring 20 is compressed, a wedge block 25 extrudes a second pressure spring 27, so that the wedge face of the wedge block 25 is placed in a sleeve 24, with the continuous upward movement of the cutter 9, at the moment, the clamping groove 26 on the cutter 9 corresponds to the wedge-shaped block 25, so that the wedge-shaped block 25 is ejected into the clamping groove 26 of the cutter 9 under the resetting action of the second pressure spring 27, at the moment, the cutter 9 is clamped under the action of the wedge-shaped block 25 and the clamping groove 26, meanwhile, the first pressure spring 20 is compressed and has a downward ejection trend, at the moment, the electric push rod 15 moves outwards to the outermost end position, the pressure rod 16 on the electric push rod 15 contacts and extrudes the first contact switch 17, at the moment, the first contact switch 17 turns on the driving motor and the first motor of the conveyor belt 5, the conveyor belt 5 drives the large-lump cutting chips wound on the conveyor belt to move towards the shaping cavity, and at the same time, the rotation of the first motor realizes the synchronous inward rotation of the two first spike rollers 4 under the meshing action of the first belt wheel 13, the second belt wheel 14 and the two first gears 12, therefore, the left ends of the two first licker-in rollers 4 are higher than the right ends of the two first licker-in rollers 4 are lower, so that after the large-ball cutting chips are contacted, the large-ball cutting chips can be pulled outwards by the first licker-in rollers 4 under the rotating action of the first licker-in rollers 4, the first arc-shaped scraper 10 enables the cutting chips hung on the roller spines to be removed, and the large-ball cutting chips are not scraped outwards by the two first licker-in rollers 4.

The large-ball cutting scraps are pushed into the shaping cavity along with the transmission of the two first licker-in rollers 4 and the conveyor belt 5 and extend out of the right end of the shaping cavity to the lower part of the second licker-in roller 8, at the moment, the two electric push rods 15 are driven to reset inwards, at the moment, the press rod 16 is separated from the first contact switch 17, the conveyor belt 5 and the first motor are closed, the cutting scraps are not conveyed rightwards, meanwhile, the vertical rod 6 drives the cross rod 7 to extrude towards the middle position when the two electric push rods 15 move inwards, the cross rod 7 is inserted into the cutting scraps and forms a grid, at the moment, along with the continuous inward resetting of the electric push rods 15, the press rod 16 contacts the second contact switch 18 to enable the second motor to rotate, at the moment, the second licker-in roller 8 rotates to drive the cutting scraps below the second licker-in roller 8 to move rightwards, at the moment, the grid formed by the cross rod, the pulled part has the tendency of being pushed into the right-side crusher by the second licker-in 8, but cutting chips are hooked, so that the pulled part falls into the crusher completely, at the moment, the rotation of the second licker-in 8 also drives the first friction wheel 28 to rotate, the first friction wheel 28 rotates to drive the second friction wheel 29 to rotate, the arc-shaped bulge 30 on the end surface of the second friction wheel 29 contacts and extrudes the end part of the L-shaped rod 31 arranged on the outer end surface side of the second friction wheel 29 in the process, the L-shaped rod 31 is driven to move outwards by the arc-shaped bulge 30 along with the rotation of the second friction wheel 29, the third pressure spring 32 is compressed and has the rebound tendency, when the L-shaped rod 31 moves outwards, the wedge-shaped block 25 is pulled towards the right side by the stretching of the second rope 33, at the moment, the second pressure spring 27 is compressed, the wedge part of the wedge-shaped block 25 is separated from the clamping groove 26, at the moment, the first rope 21 is reset along with, the first rope 21 is loosened, the cutter 9 which is separated from the wedge-shaped block 25 and clamped tightly is ejected downwards under the reset action of the first pressure spring 20, the chips hooked on one block are cut off, and at the moment, the cutting chips which are completely cut off by the cutter 9 are conveyed into a feeding port of the pulverizer by the rotation of the second licker-in 8 through the right end of the workbench 1.

After the actions are finished, the electric push rod 15 moves outwards again, the second motor stops rotating, the second licker-in 8 stops rotating, the cutter 9 is pulled upwards again, the grid is pulled away again, and the next section of cutting chips moves rightwards to separate the next section of cutting chips.

Compared with the traditional equipment, the device has the following advantages:

1. this device realizes opening and closing of the grid that has a plurality of horizontal poles 7 to constitute through the reciprocating motion of two electric putter 15, when the grid was opened completely, first licker-in 4 and conveyer belt 5 motion extrude the conveying to the plastic intracavity after with big group's cutting bits plastic and continue to move right through the plastic chamber, it has the trend of reseing to get a group to separate the big group's cutting bits of rear side to both sides through two first licker-in 4 in this process, and the plastic chamber can realize fixing the cutting bits that have shaped and remove to second licker-in 8 drive positions with the platykurtic form, this process carries out preliminary plastic convenient subsequent the pulling with the cutting bits.

2. After the cutting bits that the plastic is good moved 8 drive positions of second licker-in, two second electric putter 15 reset for the grid inserts to the cutting bits inside and realize the fixed of cutting bits, and second licker-in 8 gets electricity to begin to rotate the pulling that realizes by the cutting bits tip after fixing this moment, with most cutting bits to the right side pulling, realize the separation of cutting bits, make the cutting bits separation more high-efficient.

3. After the separation of most cutting bits is completed, hooking and connecting of some more cutting bits can be certainly stored, the hooking and connecting can prevent the separated cutting bits from continuously moving rightwards, the cutting knife 9 moves upwards and is clamped when the electric push rod 15 moves outwards, when the second licker-in 8 rotates to separate the cutting bits fixed at one end, the cutting bits are separated along with the rotating continuous cutting knife 9 clamping mechanism, at the moment, the cutting bits hooked and connected in a tightening mode are cut off by the cutting knife 9 popping out downwards, hooking and connecting are released, the dispersed cutting bits are completely transmitted to the pulverizer at the right end by the second licker-in 8, and the pulverizer can rapidly and efficiently complete a pulverizing task without accumulation and overload.

Claims

1. A cutting scrap recovery processing device comprises a horizontal workbench (1), wherein vertical supporting plates (2) are respectively arranged on the front side and the rear side of the workbench (1), and the cutting scrap recovery processing device is characterized in that a horizontal transverse plate (3) with two ends respectively fixed on the two supporting plates (2) is arranged above the middle position of the workbench (1), the transverse plate (3), the workbench (1) and the two supporting plates (2) form a shaping cavity with the left end and the right end both open, two first licker-in rollers (4) capable of synchronously rotating inwards are arranged on the front side and the rear side of the left side of the shaping cavity side by side at intervals, the left ends of the two first licker-in rollers (4) are obliquely arranged upwards, a conveying belt (5) arranged on the workbench (1) is arranged below the two first licker-in rollers (4), a vertical rod (6) is arranged on the outer side of each supporting plate (2), and the two vertical rods (, a plurality of transverse rods (7) are uniformly distributed on the inner side of each vertical rod (6) at intervals along the length direction of the vertical rod (6), the two vertical rods (6) move in opposite directions to enable the plurality of transverse rods (7) to be inserted into the inner sides of the two supporting plates (2) and form a grid to block a right opening of the shaping cavity, the two vertical rods (6) move in opposite directions until the grid completely opens the right opening of the shaping cavity, two first licker-in rollers (4) and a conveyor belt (5) start to rotate, a second licker-in roller (8) arranged between the two supporting plates (2) is arranged on the right side of the transverse rod (7), the two vertical rods (6) move in opposite directions until the grid completely closes the right opening of the shaping cavity, the second licker-in roller (8) starts to rotate, a cutter (9) capable of ejecting downwards is arranged between the second licker-in roller (8) and the transverse rod (7), a clamping mechanism is arranged above the cutter (9), and when the vertical rods, after the second licker-in (8) rotates, the clamping mechanism can be driven to release the cutter (9) and eject downwards.

2. The cutting scrap recycling device according to claim 1, wherein a first arc-shaped scraper (10) arranged below the first licker-in (4) is arranged on the outer side of each first licker-in (4), the inner arc surface of the first arc-shaped scraper (10) is attached to the roll surface of the first licker-in (4), a plurality of through grooves for the roll burrs to pass through are formed in the end portion, corresponding to the roll burrs, of the first licker-in (4) of the first arc-shaped scraper (10), a second arc-shaped scraper (11) arranged below the second licker-in (8) is arranged on the right side of the second licker-in (8), the inner arc surface of the second arc-shaped scraper (11) is attached to the roll surface of the second licker-in (8), and a plurality of through grooves for the roll burrs to pass through are formed in the end portion, corresponding to the roll burrs, of the second arc-shaped scraper (11) and the second licker-in.

3. The cutting scrap recycling device according to claim 1, wherein a first gear (12) is coaxially fixed on a left end mandrel of each first licker-in roll (4), the two first gears (12) are meshed with each other, a first belt wheel (13) is further coaxially fixed on the mandrel of one first licker-in roll (4), a second belt wheel (14) driven by a first motor is arranged on the outer side of the support plate (2), and the first belt wheel (13) is connected with the second belt wheel (14) through a belt.

4. The cutting scrap recycling device according to claim 1, wherein two electric push rods (15) corresponding to the two vertical rods (6) one by one are arranged below the working table (1), the vertical rods (6) are respectively arranged at the extending ends of the corresponding electric push rods (15), and the two electric push rods (15) can synchronously move inwards or outwards.

5. The cutting scrap recycling apparatus according to claim 1, wherein the lower end of the rear vertical rod (6) is provided with an L-shaped pressing rod (16) disposed below the electric push rod (15), the rear end of the rear electric push rod (15) is provided with a first contact switch (17) for driving the motor of the first motor and the conveyor belt (5), the second licker-in (8) is driven by the second motor, the front end of the rear electric push rod (15) is provided with a second contact switch (18) for driving the motor of the second motor, the pressing rod (16) contacts and presses the first contact switch (17) when the rear vertical plate moves outwards to the farthest position, and the pressing rod (16) contacts and presses the second contact switch (18) when the rear vertical plate moves inwards to the nearest position.

6. The cutting chip recycling device according to claim 1, wherein a housing (19) with a downward opening is provided above the cutting knife (9), a plurality of first compression springs (20) are provided at the bottom of the housing (19), one end of each first compression spring (20) is fixed at the bottom of the housing (19), the other end of each first compression spring is fixed on the cutting knife (9), a first rope (21) is provided on each vertical rod (6), a first fixed pulley (22) is fixed at the outer side of each supporting plate (2) through a supporting rod, a second fixed pulley (23) is provided above each supporting plate (2), and the free end of the first rope (21) on the same side sequentially passes through the housing (19) from the bottom of the housing (19) and is fixed on the cutting knife (9) after passing through the first fixed pulley (22) and the second fixed pulley (23).

7. The cutting scrap recycling device according to claim 1, wherein the clamping mechanism comprises two sets of sleeves (24) which are respectively arranged at the front side and the rear side of the right side wall of the housing (19), the clamping mechanism comprises a sleeve (24) with a closed right end and a communicated left end with the housing (19), a wedge block (25) is arranged in the sleeve (24), the wedge surface of the wedge block (25) faces towards the left lower end, a clamping groove (26) matched with the wedge block (25) is arranged on the cutter (9), a second pressure spring (27) is arranged at the bottom of the sleeve (24), one end of the second pressure spring (27) is fixed at the bottom of the sleeve (24), the other end of the second pressure spring is fixed on the wedge block (25), two first friction wheels (28) which are respectively arranged outside the supporting plate (2) are respectively fixed at two ends of a mandrel of the second licker-in (8), and a second friction wheel (29) which can be driven and is arranged at the outer circumferential surface of each first friction wheel, an arc-shaped protrusion (30) is arranged on the outer end face of the second friction wheel (29), two ends of the arc-shaped protrusion (30) are smoothly connected with the end face of the second friction wheel (29), an L-shaped rod (31) is arranged on the outer side of each second friction wheel (29), the end of a cross rod (7) of each L-shaped rod (31) is arranged on the outer side of the corresponding second friction wheel (29), the end of a vertical rod penetrates through and extends into the corresponding side supporting plate (2), a third pressure spring (32) capable of enabling the pull rod to move inwards is arranged on the part, arranged in the supporting plate (2), of each L-shaped rod (31), a second rope (33) is fixed at one end, arranged in the supporting plate (2), of each L-shaped rod (31), the other end of each second rope (33) penetrates through the bottom of the corresponding side sleeve (24) to be connected with the wedge block, the arc-shaped bulge (30) on the second friction wheel (29) extrudes the L-shaped rod (31) to enable the second rope (33) to be tightened and pull the wedge-shaped block (25) out of the clamping groove (26).