1. A speed limiter rope tensioning device is characterized by comprising a speed limiter (8), a speed limiter rope (7) and a tensioning wheel (1);

the speed governor (8) is arranged in a machine room at the upper part of the shaft, and the speed governor rope (7) bypasses the speed governor (8);

the tension wheel (1) is positioned at the bottom of the well;

the tensioning wheel (1) comprises a first pulley (11), a second pulley (12) and a main shaft (3);

the first pulley (11) and the second pulley (12) are adjacent and are arranged on the same main shaft (3) with gaps, and the first pulley (11) and the second pulley (12) can respectively and independently rotate around the main shaft (3) freely;

the first pulley (11) and the second pulley (12) can be fastened together through a fastener (13) so as to freely rotate around the main shaft synchronously and in the same direction;

the rope cavity of the first pulley (11) and the rope cavity of the second pulley (12) of the speed limiter rope (7) are respectively wound with at least one circle, one end of the speed limiter rope (7) is wound out of the rope cavity of one pulley in the first pulley (11) and the second pulley (12) in the clockwise direction, and the other end of the speed limiter rope (7) is wound out of the rope cavity of the other pulley in the first pulley (11) and the second pulley (12) in the anticlockwise direction.

2. The governor rope tensioning arrangement of claim 1,

the two ends of the main shaft (3) are installed on the vertical guide device (4), and the main shaft (3) can freely slide up and down along the guide device (4).

3. The governor rope tensioning arrangement of claim 1,

the guide device (4) is vertically fixed in a pit of the elevator shaft.

4. The governor rope tensioning arrangement of claim 1,

the clearance between the first pulley (11) and the second pulley (12) is smaller than 1/20 of the outer diameters of the first pulley (11) and the second pulley (12).

5. The governor rope tensioning arrangement of claim 1,

the first pulley (11) and the second pulley (12) have the same structure.

6. The governor rope tensioning arrangement of claim 1,

the first pulley (11) and the second pulley (12) respectively comprise a hub (40), a left pulley wall (41), a right pulley wall (42) and a rolling bearing (5);

the left pulley wall (41) and the right pulley wall (42) are respectively and coaxially fixed at two ends of the hub (40);

a cavity structure formed among the left pulley wall (41), the right pulley wall (42) and the hub (40) is used as a rope cavity for accommodating the speed limiter rope (7);

a rolling bearing (5) is arranged at the center of the hub (40);

the first pulley (11) and the second pulley (12) are sleeved outside the main shaft (3) through respective rolling bearings (5) and can independently rotate around the main shaft.

7. The governor rope tensioning arrangement of claim 6,

the hub (40) is provided with an axial through hole as a fastener mounting hole (401) for fastener mounting.

8. The governor rope tensioning arrangement of claim 1,

a first counter weight wheel (51) and a second counter weight wheel (52) are arranged below the tensioning wheel (1);

one end of the speed limiter rope (7) winds out of a rope cavity of the first pulley (11) in a clockwise direction and then winds around the lower side of the first counterweight wheel (51), and the other end of the speed limiter rope (7) winds out of a rope cavity of the second pulley (12) in a counterclockwise direction and then winds around the lower side of the second counterweight wheel (52).

9. The governor rope tensioning arrangement of claim 8,

the axle centers of the first counter weight pulley (51) and the second counter weight pulley (52) are respectively connected to the bottom of the shaft through a spiral spring.

10. The governor rope tensioning arrangement of claim 8,

and a rope breakage detection switch is arranged on the first counterweight wheel (51) or the second counterweight wheel (52).

11. Use of a governor rope tensioning device according to any of claims 1-10,

when the elevator normally runs, the first pulley (11) and the second pulley (12) are fastened together through a fastener, so that the first pulley (11) and the second pulley (12) synchronously and freely rotate around the main shaft (3) in the same direction;

when the elevator machine room needs to jump, the fastening piece 13 is loosened, so that the first pulley (11) and the second pulley (12) can respectively and independently rotate around the main shaft (3) freely.

12. The method of using a governor rope tensioning device of claim 11,

when the elevator normally operates:

when the elevator goes upwards, one end of a speed limiter rope (7) wound out of a rope cavity of the first pulley (11) in a clockwise direction is pulled out of the rope cavity of the first pulley (11) by a pull rod of a safety gear; the other end of the speed limiter rope (7) wound out of the rope cavity of the second pulley (12) in the anticlockwise direction is automatically retracted into the rope cavity of the second pulley (12) along with the rotation of the second pulley (12);

when the elevator goes downwards, one end of a speed limiter rope (7) which is wound out of a rope cavity of the first pulley (11) in a clockwise direction is automatically retracted into the rope cavity of the first pulley (11) along with the rotation of the first pulley (11), and the other end of the speed limiter rope (7) which is wound out of the rope cavity of the second pulley (12) in a counterclockwise direction is pulled out of the rope cavity of the second pulley (12) outwards by a pull rod of a safety gear through a rope wheel of a speed limiter (8).

13. The method of using a governor rope tensioning device of claim 11,

when the elevator machine room needs to jump:

before the elevator machine room jumps, the main shaft (3) is fixed on the current position of the guide device (4) by a limiting part;

when the elevator machine room rises, the first pulley (11) and the second pulley (12) rotate in a mode of releasing the rope outwards because the motion constraint between the first pulley (11) and the second pulley (12) is released;

after the elevator machine room jumps, the first pulley (11) and the second pulley (12) are fastened again by using a fastener, so that the elevator machine room can freely rotate around the main shaft synchronously and in the same direction; then, a limiting part of the main shaft (3) is removed, and the first pulley (11), the second pulley (12) and the main shaft (3) slide downwards along the guide device (4) by means of gravity, so that the speed governor rope (7) is automatically tensioned.

14. The method of using a governor rope tensioning device of claim 11,

when the overspeed trigger speed limiter (8) acts when the elevator car 90 runs downwards, the speed limiter (8) acts to block the speed limiter rope (7) to block the movement of the speed limiter rope (7), and the pull rod (91) is synchronously pulled; the elevator car (90) continues to move downwards, the pull rod (91) is lifted relative to the elevator car (90), and the linkage rod is triggered along with the pull rod (91) to enable the safety gear (94) to act to brake the elevator car (90).

Background

An elevator is provided with a speed governor for stopping a car in an emergency when the car falls into an overspeed state. The governor has a governor rope that moves at the same speed as the speed of the car, a sheave around which the governor rope is wound, and a governor weight that is displaced by centrifugal force that varies depending on the rotational speed of the sheave. When the car is in an overspeed state, a drive member mechanically coupled to the governor weight actuates a stop switch to cut off the power supply of the hoist. When the speed of the car is further increased after the power supply is cut off (when the car is descending), the other driving element coupled to the governor weight operates the rope gripping mechanism, and the safety gear device operates accordingly.

With the advent of super high buildings, the improvement of building efficiency of high buildings has been the subject of research in the building industry. The advent of jump elevators can effectively solve this problem. The jump elevator is an elevator used by constructors in the building construction process. The elevator machine room can be lifted by stages according to the construction progress along with the increase of the height of the building.

Most of the conventional rope systems (including a traction sheave and a compensating rope) of the jump elevator are of an open structure, a rope barrel can be arranged at the tail end of a rope, and the length of the rope generated by jump is stored in the rope barrel in advance. However, since the structure of the governor rope in the elevator system is a closed loop structure, it is difficult to install a rope drum at the end of the rope, as in other ropes, and to store the rope length generated after the machine room jumps in advance. In the conventional jump elevator system, a speed governor rope is replaced by a new rope after the machine room jumps, or the speed governor rope is placed on the top of the elevator car in advance and manually released when the machine room jumps. This results in cost waste and construction safety problems. The ability to place equipment with varying weight on the ceiling also creates significant challenges for elevator comfort and performance.

Chinese patent document CN00802659 discloses an elevator arrangement mode, which can be used in the field of jumping elevators, wherein a traction steel wire rope and a compensation cable are both stored in a rope barrel arranged in a machine room and a pit, the steel wire rope is discharged from the rope barrel in the process of jumping elevator machine room, the traction steel wire rope is open, and the structure of the storage rope is a rope barrel, but the rope can not be taken in and put out during the operation of the elevator.

Chinese patent application document CN201911005041A discloses a steel wire rope winding and unwinding system capable of winding and unwinding a compensating steel wire rope during elevator operation, which can unwind the rope and wind the rope at the same time, but two wheels are arranged on different shafts and are linked by a belt, a belt pulley is connected with a rope barrel by a clutch, and in order to solve the problem that the rope taking in and unwinding the rope is loosened due to different rope speeds generated by rope winding, the rope winding and unwinding speed of the belt pulley is adjusted by adopting different diameters.

Disclosure of Invention

The invention aims to provide a speed limiter steel wire rope tensioning device which can ensure that the rope releasing action of a speed limiter rope is automatically realized when a machine room of a jump elevator jumps, has higher safety and comfort and has low cost.

In order to solve the technical problem, the speed limiter rope tensioning device provided by the invention comprises a speed limiter 8, a speed limiter rope 7 and a tensioning wheel 1;

the speed governor 8 is arranged in a machine room at the upper part of the shaft, and the speed governor rope 7 bypasses the speed governor 8;

the tensioning wheel 1 is positioned at the bottom of the well;

the tension pulley 1 comprises a first pulley 11, a second pulley 12 and a main shaft 3;

the first pulley 11 and the second pulley 12 are adjacent and are arranged on the same main shaft 3 with a gap, and the first pulley 11 and the second pulley 12 can respectively and independently rotate around the main shaft 3 freely;

the first pulley 11 and the second pulley 12 can be fastened together through a fastening piece so as to freely rotate around the main shaft synchronously and in the same direction;

the governor rope 7 is wound at least once around the rope cavity of the first sheave 11 and the rope cavity of the second sheave 12, one end of the governor rope 7 is wound clockwise around the rope cavity of one of the first sheave 11 and the second sheave 12, and the other end of the governor rope 7 is wound counterclockwise around the rope cavity of the other of the first sheave 11 and the second sheave 12.

Preferably, both ends of the main shaft 3 are installed on the vertical guide device 4, and the main shaft 3 can freely slide up and down along the guide device 4.

Preferably, the guide means 4 are fixed vertically in the pit of the elevator shaft.

Preferably, the clearance between the first pulley 11 and the second pulley 12 is smaller than 1/20 of the outer diameters of the first pulley 11 and the second pulley 12.

Preferably, the first pulley 11 and the second pulley 12 have the same structure.

Preferably, each of the first pulley 11 and the second pulley 12 includes a hub 40, a left pulley wall 41, a right pulley wall 42, and a rolling bearing 5;

the left pulley wall 41 and the right pulley wall 42 are respectively and coaxially fixed at two ends of the hub 40;

a cavity structure formed among the left pulley wall 41, the right pulley wall 42 and the hub 40 serves as a rope cavity for accommodating the governor rope 7;

the center of the hub 40 is provided with a rolling bearing 5;

the first pulley 11 and the second pulley 12 are sleeved outside the main shaft 3 through respective rolling bearings 5 and can independently rotate around the main shaft.

Preferably, the hub 40 is provided with an axial through hole as a fastener mounting hole 401 for fastener mounting.

Preferably, a first balance weight 51 and a second balance weight 52 are provided below the tension pulley 1;

one end of the governor rope 7 is wound clockwise out of the rope cavity of the first sheave 11 and then around the lower side of the first balance weight pulley 51, and the other end of the governor rope 7 is wound counterclockwise out of the rope cavity of the second sheave 12 and then around the lower side of the second balance weight pulley 52.

Preferably, the axle centers of the first balance weight pulley 51 and the second balance weight pulley 52 are respectively connected to the bottom of the shaft through a coil spring.

Preferably, the first counterweight wheel 51 or the second counterweight wheel 52 is provided with a rope breakage detection switch.

According to the using method of the speed limiter rope tensioning device provided by the invention, when an elevator normally runs, the first pulley 11 and the second pulley 12 are fastened together through the fastening piece, so that the first pulley 11 and the second pulley 12 synchronously and freely rotate around the main shaft 3 in the same direction;

when the elevator machine room needs to jump, the fastening piece 13 is loosened, and the first pulley 11 and the second pulley 12 respectively and independently rotate around the main shaft 3.

Preferably, when the elevator is in normal operation:

when the elevator goes upwards, one end of the speed limiter rope 7 which winds out of the rope cavity of the first pulley 11 in the clockwise direction is pulled out of the rope cavity of the first pulley 11 by a safety tongs pull rod; the other end of the speed limiter rope 7 wound out of the rope cavity of the second pulley 12 in the anticlockwise direction is automatically retracted into the rope cavity of the second pulley 12 along with the rotation of the second pulley 12;

when the elevator goes down, one end of the speed governor rope 7 which is wound out of the rope cavity of the first pulley 11 in the clockwise direction is automatically retracted into the rope cavity of the first pulley 11 along with the rotation of the first pulley 11, and the other end of the speed governor rope 7 which is wound out of the rope cavity of the second pulley 12 in the counterclockwise direction is pulled out of the rope cavity of the second pulley 12 outwards by the safety tongs through the rope pulley of the speed governor 8.

Preferably, when the elevator machine room needs to jump:

before the elevator machine room jumps, the main shaft 3 is fixed on the current position of the guide device 4 by a limiting part;

when the elevator machine room rises, the first pulley 11 and the second pulley 12 rotate in a mode of outward releasing ropes because the motion constraint between the first pulley 11 and the second pulley 12 is released;

after the elevator machine room jumps, the first pulley 11 and the second pulley 12 are fastened again by using a fastener, so that the elevator machine room can freely rotate around the main shaft synchronously and in the same direction; then, the main shaft 3 stopper is removed, and the first pulley 11, the second pulley 12, and the main shaft 3 slide downward along the guide 4 by gravity, so that the governor rope 7 is automatically tensioned.

Preferably, when the overspeed trigger speed limiter 8 acts when the elevator car 90 runs downwards, the speed limiter 8 acts to block the speed limiter rope 7, so that the movement of the speed limiter rope 7 is blocked, and the pull rod 91 is synchronously pulled; the elevator car 90 continues to move downwards, so that the pull rod 91 is lifted relative to the elevator car 90, and the linkage rod is triggered along with the pull rod 91 to enable the safety gear 94 to act to brake the elevator car 90.

The speed limiter steel wire rope tensioning device can ensure that the rope releasing action of the speed limiter rope 7 can be automatically realized when the elevator machine room is lifted, and has higher safety and comfort and low cost.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the present invention are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a block diagram of one embodiment of the governor rope tensioner of the present invention;

fig. 2 is a tension sheave construction of one embodiment of the governor rope tension apparatus of the present invention;

FIG. 3 is a side view of an embodiment of the first or second pulley;

FIG. 4 is a cross-sectional view of an embodiment of the first pulley or the second pulley;

FIG. 5 is a schematic diagram of a roping direction of an embodiment of the first sheave and the second sheave;

fig. 6 is a schematic diagram of an elevator car up-run state during normal elevator operation in an embodiment of the governor rope tensioning apparatus of the present invention;

fig. 7 is a schematic view of a down-going condition of an elevator car during normal operation of an elevator in accordance with an embodiment of the governor rope tensioning apparatus of the present invention;

fig. 8 is a schematic diagram of an embodiment of the governor rope tensioning apparatus of the present invention during a jump in an elevator machine room;

fig. 9 is a schematic view of a safety gear in the action of an embodiment of the governor rope tensioning apparatus of the present invention;

fig. 10 is a schematic diagram of a governor rope tensioning apparatus of an embodiment of the present invention with a counterweight wheel.

The reference numbers in the figures illustrate:

8, a speed limiter; 7 a speed limiter rope; 1, a tension wheel; 11 a first pulley; 12 a second pulley; 13 a fastener; 3, a main shaft; 4, a guiding device; 40, a hub; 41 left pulley wall; 42 right pulley wall; 401 fastener mounting holes; 5 rolling bearings; 51 a first balance weight wheel; 52 a second counterweight wheel; 90 an elevator car; 94 safety gear; 91 a pull rod.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

As shown in fig. 6, the governor rope tension device includes a governor 8, a governor rope 7, and a tension pulley 1;

the speed governor 8 is arranged in a machine room at the upper part of the shaft, and the speed governor rope 7 bypasses the speed governor 8;

the tensioning wheel 1 is positioned at the bottom of the well;

as shown in fig. 2, the tension pulley 1 includes a first pulley 11, a second pulley 12, and a main shaft 3;

the first pulley 11 and the second pulley 12 are adjacent and are arranged on the same main shaft 3 with a gap, and the first pulley 11 and the second pulley 12 can respectively and independently rotate around the main shaft 3 freely;

the first pulley 11 and the second pulley 12 can be fastened together through a fastener 13 so as to freely rotate around the main shaft synchronously and in the same direction;

as shown in fig. 5, the governor rope 7 is wound at least once around the rope chamber of the first sheave 11 and the rope chamber of the second sheave 12, one end of the governor rope 7 is wound clockwise around the rope chamber of one of the first sheave 11 and the second sheave 12, and the other end of the governor rope 7 is wound counterclockwise around the rope chamber of the other of the first sheave 11 and the second sheave 12.

The overspeed governor wire rope overspeed device tensioner of embodiment one both can guarantee to realize the action of releasing the rope of overspeed governor rope 7 automatically when leaping elevator machine room jump, has higher security, travelling comfort again, and is with low costs moreover.

Example two

Based on the overspeed governor rope overspeed device tensioner of embodiment one, 3 both ends of main shaft are installed on vertical guider 4, and main shaft 3 can freely slide from top to bottom along guider 4.

Preferably, the guide means 4 are fixed vertically in the pit of the elevator shaft.

Preferably, the clearance between the first pulley 11 and the second pulley 12 is smaller than 1/20 of the outer diameter of the first pulley 11 and the second pulley 12.

Preferably, the first pulley 11 and the second pulley 12 have the same structure.

Preferably, as shown in fig. 3 and 4, each of the first pulley 11 and the second pulley 12 includes a hub 40, a left pulley wall 41, a right pulley wall 42, and a rolling bearing 5;

the left pulley wall 41 and the right pulley wall 42 are respectively and coaxially fixed at two ends of the hub 40;

a cavity structure formed among the left pulley wall 41, the right pulley wall 42 and the hub 40 serves as a rope cavity for accommodating the governor rope 7;

the center of the hub 40 is provided with a rolling bearing 5;

the first pulley 11 and the second pulley 12 are sleeved outside the main shaft 3 through respective rolling bearings 5 and can independently rotate around the main shaft.

Preferably, hub 40 is provided with an axial through bore as fastener mounting bore 401 for mounting fastener 13.

EXAMPLE III

As shown in fig. 10, in the governor rope tension device according to the first embodiment, a first weight pulley 51 and a second weight pulley 52 are provided below the tension pulley 1;

one end of the governor rope 7 is wound clockwise out of the rope cavity of the first sheave 11 and then around the lower side of the first balance weight pulley 51, and the other end of the governor rope 7 is wound counterclockwise out of the rope cavity of the second sheave 12 and then around the lower side of the second balance weight pulley 52.

Preferably, the axle centers of the first balance weight pulley 51 and the second balance weight pulley 52 are respectively connected to the bottom of the shaft through a coil spring.

Preferably, the first counterweight wheel 51 or the second counterweight wheel 52 is provided with a rope breakage detection switch.

In the third overspeed governor rope tensioning device in the embodiment, two counterweight wheels are respectively arranged at the two positions of the rope inlet and outlet of the tensioning wheel 1, the tightness adjustment of the overspeed governor rope 7 is stepless, and the tensioning of the overspeed governor rope 7 and the friction force on the rope wheel of the overspeed governor 8 can be ensured all the time when the rope is retracted and released; when the elevator normally operates, the counterweight wheel tensions the speed governor rope 7 on the rope releasing side through gravity or other mechanical force, so that the speed governor rope 7 entering the rope cavity is ensured to be tight, the phenomenon that the linear speed of the speed governor rope 7 and the speed governor 8 slide due to the fact that the linear speed of the rope released by the tensioning wheel 1 is inconsistent is avoided, and the speed governor 8 is ensured to accurately act.

Example four

In the method for using the speed limiter rope tensioning device of the first, second or third embodiment, when the elevator is in normal operation, the first pulley 11 and the second pulley 12 are fastened together through the fastening piece 13, so that the first pulley 11 and the second pulley 12 can freely rotate around the main shaft 3 synchronously and in the same direction;

when the elevator machine room needs to jump, the fastening piece 13 is loosened, the first pulley 11 and the second pulley 12 respectively and independently rotate around the main shaft 3 freely, and when the machine room is lifted up by the crane, the first pulley 11 and the second pulley 12 are in an independent rope releasing state.

Preferably, when the elevator is in normal operation:

when the elevator car 90 moves upwards, one end of the speed limiter rope 7 which winds out of the rope cavity of the first pulley 11 in the clockwise direction is pulled out of the rope cavity of the first pulley 11 by a pull rod 91 of a safety gear 94; the other end of the governor rope 7 wound out of the rope chamber of the second sheave 12 in the counterclockwise direction is automatically retracted into the rope chamber of the second sheave 12 as the second sheave 12 rotates, as shown in fig. 6;

when the elevator car 90 moves downward, one end of the governor rope 7 wound clockwise out of the rope chamber of the first sheave 11 is automatically retracted into the rope chamber of the first sheave 11 as the first sheave 11 rotates, and the other end of the governor rope 7 wound counterclockwise out of the rope chamber of the second sheave 12 is pulled outward out of the rope chamber of the second sheave 12 by the pull rod 91 of the safety gear 94 through the sheave of the governor 8, as shown in fig. 7.

Preferably, when the elevator machine room needs to jump:

before the elevator machine room jumps, the main shaft 3 is fixed on the current position of the guide device 4 by a limiting part;

when the elevator machine room rises, the first pulley 11 and the second pulley 12 rotate in a mode of releasing the rope outwards because the motion constraint between the first pulley 11 and the second pulley 12 is released, as shown in fig. 8;

after the elevator machine room jumps, the first pulley 11 and the second pulley 12 are fastened again by using a fastener 13, so that the elevator machine room can freely rotate around the main shaft synchronously and in the same direction; then, the main shaft 3 stopper is removed, and the first pulley 11, the second pulley 12, and the main shaft 3 slide downward along the guide 4 by gravity, so that the governor rope 7 is automatically tensioned.

When the elevator needs to restore normal operation again, the first pulley 11 and the second pulley 12 are fastened together again through the fastener 13, so that the first pulley 11 and the second pulley 12 synchronously and freely rotate around the main shaft in the same direction.

Preferably, when the overspeed trigger speed limiter 8 acts when the elevator car 90 runs downwards, the speed limiter 8 acts to block the speed limiter rope 7, so that the movement of the speed limiter rope 7 is blocked, and the pull rod 91 is synchronously pulled; the elevator car 90 continues to move downwards, so that the pull rod 91 is lifted relative to the elevator car 90, and the linkage rod is triggered along with the pull rod 91 to actuate the safety gear 94 to brake the elevator car 90, as shown in fig. 9.

In the using method of the speed limiter rope tensioning device according to the fourth embodiment, when an elevator runs normally, the first pulley 11 and the second pulley 12 synchronously and freely rotate around the main shaft 3 in the same direction, and because the rope winding modes of the first pulley 11 and the second pulley 12 are opposite, when the first pulley 11 and the second pulley 12 rotate, the rope in one pulley rope cavity is outwards placed, and the rope in the other pulley rope cavity is inwards placed; when the elevator normally runs, if the elevator car 90 goes upwards, one end of the speed limiter rope 7 is pulled out of a rope cavity of the first pulley 11 by a pull rod 91 of the safety tongs 94; the other end of the speed limiter rope 7 is automatically retracted into a rope cavity of the second pulley 12 along with the rotation of the second pulley 12; when the elevator car moves downwards, one end of the speed governor rope 7 is pulled out of the second pulley 12 by the pull rod 91 of the safety tongs 94 through the rope wheel of the speed governor 8, and the other end of the speed governor rope 7 is automatically retracted into the rope cavity of the first pulley 11 through the rotation of the first pulley 11. When the elevator machine room rises, the fastening piece 13 is loosened to enable the first pulley 11 and the second pulley 12 to respectively and independently rotate freely around the main shaft 3, the machine room is lifted upwards by the crane, and the first pulley 11 and the second pulley 12 are in an independent rope releasing state.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.