CN110984251B

CN110984251B - Walking type static load test platform machine

Info

Publication number: CN110984251B
Application number: CN201911336818.XA
Authority: CN
Inventors: 顾欣; 汪梦骐; 杨国兴; 田乾乾
Original assignee: Jiangsu Yadao Construction Engineering Testing Co ltd
Current assignee: Jiangsu Yadao Construction Engineering Testing Co ltd
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2021-06-08
Anticipated expiration: 2039-12-23
Also published as: CN110984251A

Abstract

The invention relates to a walking type static load test platform machine which is applied to the technical field of building detection equipment and comprises a walking type platform, wherein a vertical directional sleeve is arranged on the walking type platform, a directional column penetrates through the directional sleeve, a horizontal bearing plate is arranged at the upper end of the directional column, baffles are arranged on two sides of the bearing plate on the walking type platform, a guide wheel and a guide groove are respectively arranged on the end part of the bearing plate and the side wall of the baffle, and part of the guide wheel is inserted into the guide groove; a plurality of balancing weights are stacked on the walking platform, and a feeding device used for stacking the balancing weights on the bearing plate is arranged on the walking platform. The invention has the effect of improving the detection efficiency of the engineering pile.

Description

Walking type static load test platform machine

Technical Field

The invention relates to the technical field of building detection equipment, in particular to a walking type static load test platform machine.

Background

The static load test of the pile foundation is a technology for detecting the bearing capacity of the pile foundation in engineering, and is used for detecting the bearing capacity, the settling volume and the like of a single pile and judging whether the bearing capacity, the settling volume and the like meet the design requirements or not. At present, a method for detecting an engineering pile mainly comprises a static load experiment, wherein a bearing platform is erected on a pile head by adopting a support and channel steel, and then a balancing weight is piled on the bearing platform to apply pressure. Because the engineering pile that waits to detect on the building site is large in quantity, after having detected an engineering pile at every turn, need lift off the balancing weight through the loop wheel machine, then dismantle the bearing platform and set up on another engineering pile that needs to detect again, pile up each balancing weight on the bearing platform through the loop wheel machine afterwards, need repeated a large amount of balancing weights uninstallation, pile up and the setting up of bearing platform, dismantlement work for the detection efficiency of engineering pile is lower.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a walking type static load test platform machine which has the effect of improving the detection efficiency of an engineering pile.

The above object of the present invention is achieved by the following technical solutions: a walking type static load test platform machine comprises a walking type platform, wherein a vertical orientation sleeve is arranged on the walking type platform, an orientation column penetrates through the orientation sleeve, a horizontal bearing plate is arranged at the upper end of the orientation column, baffles are arranged on two sides of the bearing plate on the walking type platform, a guide wheel and a guide groove are respectively arranged on the end part of the bearing plate and the side wall of each baffle, and the guide wheel is partially inserted into the guide groove; a plurality of balancing weights are stacked on the walking platform, and a feeding device used for stacking the balancing weights on the bearing plate is arranged on the walking platform.

By adopting the technical scheme, during detection, an operator firstly drives the walking platform to the position of a pile to be detected, then inserts the directional column into the directional sleeve and enables the directional column to abut against the pile head, the counter weights are stacked on the bearing plate one by one through the feeding device, pressure is applied to the pile, after the detection is finished, the feeding device sends the counter weights back to the original position, the operator moves the directional column to be separated from the pile, the walking platform is moved to the next position of the pile to be detected, the steps are repeated, automatic stacking and unloading of the counter weights are realized, the platform does not need to be repeatedly built, the construction time is saved, and the efficiency of pile foundation detection is improved; the guide wheels are matched with the guide grooves to limit the deflection of the bearing plate, so that the stability of the force application of the directional column to the pile foundation is improved, and the accuracy of a detection result is improved; simultaneously the operator can freely increase and decrease the quantity of balancing weight on the loading board according to the detection demand, and then the adjustment is to the size of pile foundation applied load, and the flexibility is high.

The present invention in a preferred example may be further configured to: the feeding device comprises two slide rails, two slide bars and vertical upright rods arranged on the two slide bars, the two ends of each slide bar are rotatably connected with track wheels, the track wheels roll along the slide rails, a supporting plate which moves along the height direction of the upright rods is connected between the two upright rods in a sliding manner, a shifting fork is arranged on the supporting plate, one end, away from the slide bars, of each upright rod is connected with a cross beam, a lifting piece used for driving the supporting plate to move is arranged on the cross beam, the two slide rails are distributed on the two sides of the balancing weight, a driving piece used for driving the slide bars to move is arranged on the walking platform, two first sinking grooves which are parallel to each other are formed in the top surface and the bottom surface of the balancing weight, and two.

Through adopting above-mentioned technical scheme, a lift drive backup pad descends, make the balancing weight of shift fork top corresponding, driving piece drive slide bar gos forward, it inserts two first heavy inslots to drive the shift fork, a lift drive backup pad rises, just lift this balancing weight, afterwards, driving piece drive slide bar continues to go forward, make the balancing weight remove to the loading board top, the shift fork descends to the heavy inslot of second, reset after supporting the balancing weight on the loading board, it is simple swift, and adopt rail wheel and slide rail matched with mode to remove, frictional resistance is little, operate steadily.

The present invention in a preferred example may be further configured to: the driving piece comprises two winches, traction ropes are wound on rollers of the two winches, and the two traction ropes are connected with two ends of the sliding rod respectively.

Through adopting above-mentioned technical scheme, two hoist engines start simultaneously, and one of them rolling haulage rope, another release haulage rope, alright pulling slide bar reciprocating motion, simple structure, traction force is big.

The present invention in a preferred example may be further configured to: the lifting piece comprises a hydraulic cylinder arranged on the cross beam, and a piston rod of the hydraulic cylinder is connected with the supporting plate.

Through adopting above-mentioned technical scheme, the pneumatic cylinder starts, and its piston rod extension or shorten alright drive the backup pad and reciprocate convenient and fast.

The present invention in a preferred example may be further configured to: and the shifting fork is provided with an anti-slip pad.

Through adopting above-mentioned technical scheme, the slipmat has reduced balancing weight and shift fork and has taken place the possibility of skidding.

The present invention in a preferred example may be further configured to: the supporting plate is provided with a guide pillar, and the guide pillar upwards penetrates through the supporting frame.

Through adopting above-mentioned technical scheme, the guide pillar has played the guide effect to the backup pad, has stabilized the removal of backup pad.

The present invention in a preferred example may be further configured to: each through-hole has all been seted up on the balancing weight, each the through-hole runs through the gag lever post, the gag lever post is connected on walking platform.

Through adopting above-mentioned technical scheme, the removal of balancing weight has been restricted through the cooperation of gag lever post and through-hole to make the balancing weight keep stacking neatly.

The present invention in a preferred example may be further configured to: the walking platform is provided with a plurality of base plates, each base plate is vertically provided with a telescopic cylinder, one end of each telescopic cylinder penetrates out of the walking platform downwards, a mandrel is arranged in each telescopic cylinder, the lower end of each mandrel is provided with a spiral drill rod, and the base plates are provided with driving devices used for driving the mandrels to rotate and enabling the mandrels to move up and down.

Through adopting above-mentioned technical scheme, bore spiral drill pipe into ground through drive arrangement, played restriction and firm effect to walking platform.

The present invention in a preferred example may be further configured to: the driving device comprises a shaft sleeve, a first servo motor and a spline shaft, the shaft sleeve slides in the telescopic cylinder, a central shaft is rotatably connected in the shaft sleeve, one end of the central shaft is connected with the mandrel, the other end of the central shaft is provided with a spline groove, the walking platform is provided with a support frame, the spline shaft is rotatably connected to the support frame, one end of the spline shaft is inserted into the spline groove, the first servo motor is arranged on the support frame, and a motor shaft of the first servo motor is connected with the spline shaft; the improved bearing is characterized in that the shaft sleeve is provided with two lug plates which are symmetrically distributed, the support frame is connected with two screw rods in a rotating mode, the screw rods penetrate through the two lug plates respectively and are in threaded connection with the lug plates, and the support frame is provided with a rotating part which is used for driving the two screw rods to rotate simultaneously.

Through adopting above-mentioned technical scheme, a servo motor starts, and the drive integral key shaft rotates, and the integral key shaft passes through the center pin and drives the dabber rotation, and the dabber drives the auger stem rotation, rotates two screw rods of a drive simultaneously and rotates for two otic placodes drive the whole decline of axle sleeve, and auger stem contradicts with ground and bores gradually in the soil body, and is simple swift, convenient nimble.

The present invention in a preferred example may be further configured to: the rotating part comprises a first chain wheel, a chain and a second servo motor, the supporting frame is worn out of the upper end of the screw rod, one end of the upper end of the screw rod is connected with the first chain wheel, the chain is connected with the two first chain wheels, the second servo motor is installed on the supporting frame, and a second chain wheel meshed with the chain is arranged on a motor shaft of the second servo motor.

Through adopting above-mentioned technical scheme, second servo motor starts, drives the second sprocket and rotates, and the second sprocket passes through two first sprockets of chain drive and rotates to make two screw rods rotate, transmission simple structure, the drive ratio is accurate, and a driving source is shared to two screw rods, saves the resource.

In summary, the invention includes at least one of the following beneficial technical effects:

1. the automatic stacking and unloading of the balancing weight is realized, the structure is based on a walking platform, the maneuverability is strong, the time required by repeatedly building the platform for transmission detection is saved, and the efficiency of pile foundation detection is improved;

2. utilize the auger stem to bore and restrict walking platform in the soil body, improved its stability in the testing process, and drive arrangement has realized that the auger stem reciprocates when the rotation, compact structure, flexibility.

Drawings

Fig. 1 is a schematic structural diagram of the present embodiment.

Fig. 2 is an enlarged view at a in fig. 1.

Fig. 3 is a schematic structural diagram of a feeding device according to the present embodiment.

Fig. 4 is an enlarged view of fig. 3 at B.

Fig. 5 is a schematic structural diagram for embodying the driving apparatus in this embodiment.

Fig. 6 is a schematic structural view for embodying the sleeve and the spline shaft of the present embodiment.

In the figure, 1, a walking platform; 11. an orientation sleeve; 12. a directional column; 121. a carrier plate; 1211. a second sink tank; 13. a baffle plate; 14. a guide wheel; 15. a guide groove; 16. a balancing weight; 161. a first sink tank; 17. a guide post; 18. a through hole; 19. a limiting rod; 2. a feeding device; 21. a slide rail; 22. a slide bar; 221. a rail wheel; 23. erecting a rod; 24. a support plate; 25. a shifting fork; 251. a non-slip mat; 26. a cross beam; 3. a drive member; 31. a winch; 32. a hauling rope; 4. a lifting member; 41. a hydraulic cylinder; 5. a substrate; 51. a telescopic cylinder; 52. a mandrel; 521. a auger stem; 6. a drive device; 61. a first servo motor; 62. a shaft sleeve; 63. a spline shaft; 64. a central shaft; 641. a spline groove; 65. a support frame; 66. an ear plate; 67. a screw; 7. a rotating member; 71. a first sprocket; 72. a second servo motor; 721. a second sprocket; 73. and a chain.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The walking type static load test platform machine disclosed by the invention comprises a walking type platform 1 and the walking type platform 1 machine, wherein a vertical orientation sleeve 11 is arranged on the walking type platform 1, orientation columns 12 which are coaxially distributed are arranged in the orientation sleeve 11 in a penetrating mode, two ends of each orientation column 12 penetrate through the orientation sleeve 11, a horizontal bearing plate 121 is arranged at the upper end of each orientation column 12, baffle plates 13 are arranged on two sides of the bearing plate 121 of the walking type platform 1, the baffle plates 13 are perpendicular to the bearing plate 121, guide wheels 14 are rotatably connected to the end portions of the bearing plate 121, guide grooves 15 corresponding to the guide wheels 14 are formed in the side walls of the baffle plates 13, the guide grooves 15 extend along the height direction of the baffle plates 13, and meanwhile, the guide wheels 14 abut against the bottoms of the guide grooves 15 to limit the inclination of the bearing plate 121.

As shown in fig. 3 and 4, a plurality of balance weights 16 are stacked on the walking platform 1, the balance weights 16 are distributed opposite to the bearing plate 121, two through holes 18 are formed in each balance weight 16, each through hole 18 is divided into two groups, two limiting rods 19 are arranged on the walking platform 1, the two limiting rods 19 respectively penetrate through the two groups of through holes 18 to connect the balance weights 16 in series, so as to limit the positions of the balance weights 16, and the feeding device 2 for stacking the balance weights 16 on the bearing plate 121 is arranged on the walking platform 1.

As shown in fig. 3 and 4, the feeding device 2 includes two slide rails 21, two slide bars 22, and a vertical rod 23 vertically disposed on the two slide bars 22, the two slide rails 21 are both disposed on the walking platform 1 and distributed on two opposite sides of the two baffles 13, the counterweight 16 is also located between the two baffles 13, the two slide bars 22 respectively correspond to the two slide rails 21, two ends of each slide bar 22 are both rotatably connected with track wheels 221, and the track wheels 221 roll along the slide rails 21; the two upright rods 23 are symmetrically distributed, a supporting plate 24 which moves along the height direction of the two upright rods 23 is connected between the two upright rods 23 in a sliding mode, a U-shaped shifting fork 25 is arranged in the middle of the supporting plate 24, an anti-slip pad 251 is arranged on the shifting fork 25, a guide pillar 17 is arranged on the supporting plate 24, one end of the guide pillar 17 upwards penetrates out of a supporting frame 65, one ends, far away from the sliding rod 22, of the two upright rods 23 are connected through a cross beam 26, two first sinking grooves 161 which are parallel to each other are formed in the top surface and the bottom surface of each balancing weight 16, two second sinking grooves 1211 are formed in the bearing plate 121, and the depths of the first; the walking platform 1 is provided with a driving piece 3 for driving the sliding rod 22 to move, and the cross beam 26 is provided with a lifting piece 4 for driving the supporting plate 24 to move.

As shown in fig. 3, the driving member 3 includes two winches 31 installed on the walking platform 1, the two winches 31 are distributed at two ends of the sliding rail 21 along the length direction, pulling ropes 32 are wound on the rollers of the two winches 31, and the two pulling ropes 32 are respectively connected with two ends of the sliding rod 22. Two winches 31 are started, one releases the pulling rope 32, and the other winds the pulling rope 32, so that the sliding rod 22 can be pulled to move.

As shown in fig. 3, the lifting member 4 includes two hydraulic cylinders 41 disposed on the cross member 26, and the piston rods of the two hydraulic cylinders 41 both penetrate the cross member 26 downward and are connected to both ends of the support plate 24, respectively.

As shown in fig. 5 and 6, the walking platform 1 is provided with a plurality of base plates 5, the number of the base plates 5 is preferably two and is distributed at two ends of the walking platform 1, each base plate 5 is vertically provided with a telescopic cylinder 51, one end of the telescopic cylinder 51 penetrates out of the walking platform 1 downwards, a mandrel 52 is arranged in the telescopic cylinder 51 and is distributed coaxially with the telescopic cylinder, the lower end of the mandrel 52 is provided with a spiral drill pipe 521, and the base plate 5 is provided with a driving device 6 for driving the mandrel 52 to rotate and enabling the mandrel 52 to move up and down.

As shown in fig. 5 and 6, the driving device 6 includes a shaft sleeve 62 coaxially sliding in the telescopic cylinder 51, both ends of the shaft sleeve 62 extend out of the telescopic cylinder 51, and the shaft sleeve 62 is rotatably connected with a central shaft 64, one end of the central shaft 64 is connected with the core shaft 52, the other end is provided with a spline groove 641 extending along the axial direction thereof, the walking platform 1 is provided with a support frame 65, the support frame 65 is rotatably connected with a spline shaft 63 and two screws 67, wherein the spline shaft 63 is located between the two screws 67, one end of the spline shaft 63 is inserted downwards into the spline groove 641, the support frame 65 is provided with a first servo motor 61, and a motor shaft of the first servo motor 61 is connected with the spline shaft 63; the upper end of the shaft sleeve 62 is provided with two ear plates 66 which are symmetrically distributed, the two screw rods 67 respectively penetrate through the two ear plates 66, the screw rods 67 are in threaded connection with the ear plates 66, and the supporting frame 65 is provided with a rotating part 7 which is used for driving the two screw rods 67 to rotate simultaneously.

As shown in fig. 5, the rotating member 7 includes two first chain wheels 71 and two second servo motors 72 mounted on the supporting frame 65, the upper ends of the two screws 67 penetrate the supporting frame 65, and the penetrating ends are connected to the first chain wheels 71, a second chain wheel 721 is disposed on a motor shaft of the second servo motor 72, and the second chain wheel 721 and the two first chain wheels 71 are distributed in a triangular manner and connected to each other by an annular chain 73. The second servo motor 72 is started to drive the second chain wheel 721 to rotate, the second chain wheel 721 drives the two first chain wheels 71 to rotate through the chain 73, the two first chain wheels 71 drive the two screws 67 to rotate, and therefore the lug plate 66 is driven to drive the shaft sleeve 62 to move.

The implementation principle of the embodiment is as follows: an operator drives the walking platform 1 to a pile foundation to be detected, enables the orientation sleeve 11 to be opposite to the pile foundation, and then moves the orientation column 12 to abut against a pile head; first servo motor 61 starts, drives the integral key shaft 63 and rotates, and integral key shaft 63 drives dabber 52 through center pin 64 and rotates, and dabber 52 drives auger stem 521 and rotates, and second servo motor 72 starts afterwards, drives two screw rods 67 and rotates simultaneously, and otic placode 66 drives axle sleeve 62 and descends for auger stem 521 contradicts with ground, and along with axle sleeve 62's continuation decline, auger stem 521 bores in the soil body, and first servo motor 61 and second servo motor 72 pause.

The hydraulic cylinder 41 is started to push the support plate 24 to move downwards to drive the shifting fork 25 to be opposite to the uppermost balancing weight 16, the winch 31 is started to drive the sliding rod 22 to move forwards, so that the shifting fork 25 is inserted into the two first sinking grooves 161 corresponding to the bottom surfaces of the balancing weights 16, the hydraulic cylinder 41 drives the support plate 24 to ascend, after the shifting fork 25 upwards supports the balancing weights 16 and separates the balancing weights from the rest of the balancing weights 16, the winch 31 continues to drive the sliding rod 22 to move forwards, so that the balancing weights 16 move to the upper side of the bearing plate 121, the hydraulic cylinder 41 drives the support plate 24 to descend, the shifting fork 25 falls into the two second sinking grooves 1211, and the balancing weights 16 are placed; after the arrangement is completed, the winch 31 pulls the sliding rod 22 to move backwards, so that the shifting fork 25 moves out of the second sinking groove 1211, the hydraulic cylinder 41 drives the supporting plate 24 to ascend and be higher than the counterweight block 16, the winch 31 continuously pulls the sliding rod 22 to move backwards, the hydraulic cylinder 41 drives the supporting plate 24 to descend after the shifting fork 25 passes over the counterweight block 16, so that the shifting fork 25 is opposite to the second counterweight block 16, the steps are repeated, the counterweight blocks 16 can be stacked on the bearing plate 121 one by one, and the directional column 12 is pressed on the pile head under the action of the gravity of the counterweight block 16; during actual detection, the weight of every balancing weight 16 is the same, the operator can be according to actual need, stack corresponding quantity balancing weight 16 on loading board 121, thereby adjust the ballasted size to the pile foundation, it is convenient nimble, after the detection, first servo motor 61 and second servo motor 72 reverse, it is external with the soil body to carry auger stem 521, drive arrangement 6 unloads balancing weight 16 on loading board 121 one by one and puts back the original place according to opposite operation simultaneously, the automatic heap of balancing weight 16 is unloaded, and the structure is based on walking platform 1, mobility is strong, saved the transmission and detected the required time of the repeated platform of building of needs, the efficiency of pile foundation detection has been improved.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims

1. The utility model provides a walking static test platform machine, includes walking platform (1), its characterized in that: a vertical orientation sleeve (11) is arranged on the walking platform (1), an orientation column (12) penetrates through the orientation sleeve (11), a horizontal bearing plate (121) is arranged at the upper end of the orientation column (12), baffles (13) are arranged on the two sides of the bearing plate (121) of the walking platform (1), a guide wheel (14) and a guide groove (15) are respectively arranged on the end part of the bearing plate (121) and the side wall of the baffle (13), and part of the guide wheel (14) is inserted into the guide groove (15); a plurality of balancing weights (16) are stacked on the walking platform (1), and a feeding device (2) used for stacking the balancing weights (16) on the bearing plate (121) is arranged on the walking platform (1);

the feeding device (2) comprises two sliding rails (21), two sliding rods (22) and upright rods (23) vertically arranged on the two sliding rods (22), two ends of each sliding rod (22) are rotatably connected with rail wheels (221), each rail wheel (221) rolls along the corresponding sliding rail (21), a supporting plate (24) moving along the height direction of the corresponding upright rod (23) is slidably connected between the two upright rods (23), each supporting plate (24) is provided with a shifting fork (25), one ends, far away from the corresponding sliding rod (22), of the two upright rods (23) are connected through a cross beam (26), each cross beam (26) is provided with a lifting piece (4) used for driving the corresponding supporting plate (24) to move, the two sliding rails (21) are distributed on two sides of a counterweight block (16), a driving piece (3) used for driving the corresponding sliding rods (22) to move is arranged on the walking platform (1), and two first sinking grooves (161) which are parallel to each other are formed in the top surface and the bottom surface, two second sinking grooves (1211) are formed in the bearing plate (121);

the driving piece (3) comprises two winches (31), traction ropes (32) are wound on rollers of the two winches (31), and the two traction ropes (32) are respectively connected with two ends of the sliding rod (22);

the lifting piece (4) comprises a hydraulic cylinder (41) arranged on the cross beam (26), and a piston rod of the hydraulic cylinder (41) is connected with the supporting plate (24).

2. The walking type static load test platform machine as claimed in claim 1, wherein: and the shifting fork (25) is provided with an anti-skid pad (251).

3. The walking type static load test platform machine as claimed in claim 2, wherein: the support plate (24) is provided with a guide post (17), and the guide post (17) upwards penetrates through the support frame (65).

4. A walking type static load test platform machine according to claim 3, wherein: each balancing weight (16) is provided with a through hole (18), each through hole (18) penetrates through a limiting rod (19), and the limiting rods (19) are connected to the walking platform (1).

5. The walking type static load test platform machine as claimed in claim 1, wherein: the walking platform is characterized in that a plurality of base plates (5) are arranged on the walking platform (1), a telescopic cylinder (51) is vertically arranged on each base plate (5), one end of each telescopic cylinder (51) penetrates out of the walking platform (1) downwards, a mandrel (52) is arranged in each telescopic cylinder (51), a spiral drill rod (521) is arranged at the lower end of each mandrel (52), and a driving device (6) used for driving the mandrels (52) to rotate and enabling the mandrels (52) to move up and down is arranged on each base plate (5).

6. The walking type static load test platform machine as claimed in claim 5, wherein: the driving device (6) comprises a shaft sleeve (62), a first servo motor (61) and a spline shaft (63), the shaft sleeve (62) slides in the telescopic cylinder (51), a central shaft (64) is rotationally connected to the shaft sleeve (62), one end of the central shaft (64) is connected with the mandrel (52), a spline groove (641) is formed in the other end of the central shaft, a supporting frame (65) is arranged on the walking platform (1), the spline shaft (63) is rotationally connected to the supporting frame (65), one end of the spline shaft (63) is inserted into the spline groove (641), the first servo motor (61) is installed on the supporting frame (65), and a motor shaft of the first servo motor (61) is connected with the spline shaft (63); be equipped with otic placode (66) of two symmetric distributions on axle sleeve (62), support frame (65) internal rotation is connected with two screw rods (67), two screw rod (67) pass two otic placodes (66) respectively, and screw rod (67) and otic placode (66) threaded connection, be equipped with on support frame (65) and be used for driving two screw rods (67) pivoted rotation piece (7) simultaneously.

7. The walking type static load test platform machine as claimed in claim 6, wherein: rotate piece (7) and include first sprocket (71), chain (73) and second servo motor (72), two support frame (65) are all worn out to the upper end of screw rod (67), and the one end of wearing out is connected with first sprocket (71), chain (73) are connected with two first sprockets (71), second servo motor (72) are installed on support frame (65), and are equipped with on the motor shaft of second servo motor (72) with second sprocket (721) of chain (73) looks meshing.