CN220165622U - Hoisting equipment for acid etching solution electrolysis - Google Patents

Abstract

The utility model discloses hoisting equipment for electrolysis of an acidic etching solution, which belongs to the technical field of hoisting and comprises a top plate, wherein a movable carrying component for moving an electrolytic plate component is arranged on the top plate; the movable carrying component is provided with a hoisting component for hoisting the electrolytic plate component; an electrolytic plate assembly for separating out electrolytic substances is arranged on the hoisting assembly; the mobile carrier assembly is provided with a liquid collecting assembly for collecting electrolyte; the liquid collecting assembly comprises an electric push rod, a round rod, a rectangular box, a second hanging ring, a rectangular opening and a liquid discharge pipe, the electric push rod, the round rod, the rectangular box, the second hanging ring, the rectangular opening and the liquid discharge pipe are mutually matched, no electrolyte drops fall on the working ground when the electrolytic plate assembly is lifted out of the electrolytic tank, the working of workers is affected, and the recovered electrolyte can be further returned to the electrolytic tank for continuous use, so that the cost is saved.

Description

Hoisting equipment for acid etching solution electrolysis

Technical Field

The utility model relates to the technical field of hoisting, in particular to hoisting equipment for acid etching solution electrolysis.

Background

The hoisting device for electrolysis generally consists of a crane, a sling, a steel wire rope, a bracket, a clamp and the like. When in hoisting, the bracket is firstly installed, the electrolytic plate is stably placed on the bracket, then the hanging strips are fixed at the two ends of the copper plate by using the steel wire ropes, the hanging strips are hung on the crane, and then the two ends of the copper plate are respectively fixed by using the clamps so as to prevent the copper plate from sliding.

The utility model provides an electrolytic copper production hoist device of prior art, for example chinese utility model CN210084777U, includes crossbeam, supporting leg, electrolytic cell, base and mount, the both ends bottom of crossbeam is equipped with the supporting leg, the lower extreme of supporting leg is equipped with the bottom, is equipped with the electrolytic cell between two supporting legs, the below of crossbeam is equipped with the take-up pulley, and the both sides of this take-up pulley are connected with the crossbeam bottom through the link, be fixed with first motor on the crossbeam, the output of this first motor is connected with the input of take-up pulley through the drive belt, the below of crossbeam is equipped with the mount, and the top of this mount is connected with the horizontal pole through the connecting rod, and the upper surface intermediate position of this horizontal pole is equipped with the go-between, the winding has the rope on the take-up pulley, and the other end and the go-between of this rope are connected, be equipped with the slide bar in the cavity, the slide bar cover has the solid fixed ring, the quantity of guy ring is a plurality of to centre gripping has the copper between the two adjacent solid fixed rings.

However, the lifting device for producing electrolytic copper has the problem that in the lifting process of the electrolytic copper plate, some electrolyte is carried by the electrolytic copper plate out of the electrolytic cell, and the electrolyte can drip onto the working ground to influence the normal work of staff.

Based on the above, the utility model designs a lifting device for the electrolysis of the acidic etching solution to solve the problems.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model provides hoisting equipment for the electrolysis of an acidic etching solution.

In order to achieve the above purpose, the utility model is realized by the following technical scheme:

a hoisting device for acid etching solution electrolysis comprises a top plate,

the movable carrier assembly for moving the electrolytic plate assembly is arranged on the top plate;

the movable carrying component is provided with a hoisting component for hoisting the electrolytic plate component;

an electrolytic plate assembly for separating out electrolytic substances is arranged on the hoisting assembly;

the mobile carrier assembly is provided with a liquid collecting assembly for collecting electrolyte;

the liquid collection assembly comprises an electric push rod, a round rod, a rectangular box, a second hanging ring, a rectangular opening and a liquid discharge pipe, wherein the electric push rod is symmetrically installed on the movable object carrying assembly, the output end of the electric push rod is fixedly connected with one end of the round rod, the other end of the round rod is fixedly connected with the second hanging ring, the second hanging ring is fixedly connected with the rectangular box, the rectangular opening is formed in the rectangular box, the liquid discharge pipe is fixedly installed at the bottom of the rectangular box, and sealing devices are respectively installed on one sides of the two groups of rectangular boxes, which are close to each other.

Still further, remove and carry the thing subassembly and include rectangular slide block and carry the thing case, rectangular slide block and the spout laminating sliding connection who offers on the roof, rectangular slide block's bottom fixed mounting has and carries the thing case, it is connected with hoist and mount subassembly and liquid collection subassembly respectively to carry the thing case.

Further, electric push rods are fixedly installed on the left and right inner walls of the carrying box respectively.

Still further, the hoist and mount subassembly includes lifting unit and clamping unit, install lifting unit in the year thing case, lifting unit is connected with clamping unit.

Still further, lifting unit includes motor, first gear, second gear, first threaded rod, thread bush, direction gag lever post and first rectangular plate, motor fixed mounting is at the interior top of carrying the thing case, the output fixed mounting of motor has first gear, the bottom of carrying the thing case rotates and installs first threaded rod, the top fixed mounting of first threaded rod has the second gear, the second gear is connected with first gear engagement, thread bush and first threaded rod threaded connection, thread bush outside both ends respectively fixed mounting have first rectangular plate, the direction gag lever post passes first rectangular plate, and the one end and the bottom fixed connection of carrying the thing case of direction gag lever post, the one end and the clamping unit connection of thread bush are kept away from to first rectangular plate.

Further, the length of the guide limiting rod is the same as that of the first threaded rod.

Still further, the clamping assembly includes telescopic link, first splint, second splint, movable groove, rack, second threaded rod and rotation subassembly, the one end that the thread bush was kept away from to first rectangular plate and the top fixed connection of telescopic link, the bottom and the first splint fixed connection of telescopic link, the movable groove has been seted up to the lower extreme of first splint, the both ends of second threaded rod are rotated with the inner wall in movable groove respectively and are connected, and the one end of second threaded rod passes first splint, the one end fixed connection of rotation subassembly and second threaded rod, both ends are laminated sliding connection with the top of first splint about the bottom of second splint, second splint bottom fixed mounting has the rack, the lower extreme and the second threaded rod meshing of rack are connected, the left and right sides outer wall of rack is laminated sliding connection with the inner wall in movable groove respectively.

Further, the first clamping plate is L-shaped.

Still further, the electrolytic plate subassembly includes electrolytic plate, second rectangular plate and first string of holding the ring, the lower extreme of second rectangular plate has the electrolytic plate, the both ends are fixed mounting respectively has first string of holding the ring about the second rectangular plate, first string of holding the ring and first splint and second splint laminating contact respectively.

Further, the lower end of the electrolytic plate is positioned in the rectangular box.

Advantageous effects

When the electrolytic plate assembly is lifted away from the electrolytic tank, the electric push rod of the liquid collecting assembly is opened, the electric push rod drives the round rod to shrink inwards, the round rod drives the rectangular box to move inwards through the second hanging ring, after the two groups of rectangular boxes are contacted, the lower end of the electrolytic plate assembly is just surrounded, electrolyte brought out of the electrolytic plate assembly from the electrolytic tank directly flows into the rectangular box, before discharging, the valve on the liquid discharge pipe is opened, electrolyte in the rectangular box is sent into the collector, then the electric push rod is controlled to push the round rod outwards, the round rod drives the rectangular box to move outwards slowly, and the electrolyte can be discharged until the two groups of rectangular boxes do not surround the electrolytic plate assembly any more.

According to the utility model, the motor, the first gear, the second gear, the first threaded rod, the threaded sleeve, the guide limiting rod and the first rectangular plate are mutually matched, so that the electrolytic plate assembly cannot shake when being hoisted.

The utility model can vertically adjust the position of the first clamping plate through the telescopic rod, so as to clamp the electrolytic plate assembly conveniently, and the distance between the first clamping plate and the second clamping plate can be adjusted to clamp the electrolytic plate assembly of different types through the mutual matching of the first clamping plate, the second clamping plate, the movable groove, the rack, the second threaded rod and the rotating assembly.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is evident that the drawings in the following description are only some embodiments of the present utility model and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a perspective view of a hoisting device for electrolyzing an acidic etching solution;

FIG. 2 is a front view of a hoisting device for acidic etching solution electrolysis in the utility model;

FIG. 3 is a right side view of a hoisting device for electrolyzing an acidic etching solution;

FIG. 4 is a second perspective view of a hoisting device for electrolyzing an acidic etching solution;

FIG. 5 is a cross-sectional view taken along the direction A-A of FIG. 2;

FIG. 6 is a cross-sectional view taken along the B-B direction of FIG. 2;

FIG. 7 is a cross-sectional view taken along the direction C-C of FIG. 3;

fig. 8 is an enlarged view of D in fig. 5.

Reference numerals in the drawings represent respectively:

1. a top plate; 2. moving the carrier assembly; 21. a rectangular slide block; 22. a carrying case; 3. hoisting the assembly; 31. a lifting assembly; 311. a motor; 312. a first gear; 313. a second gear; 314. a first threaded rod; 315. a thread sleeve; 316. a guide limit rod; 317. a first rectangular plate; 32. a clamping assembly; 321. a telescopic rod; 322. a first clamping plate; 323. a second clamping plate; 324. a movable groove; 325. a rack; 326. a second threaded rod; 327. a rotating assembly; 4. an electrolytic plate assembly; 41. an electrolytic plate; 42. a second rectangular plate; 43. a first hanging ring; 5. a liquid collection assembly; 51. an electric push rod; 52. a round bar; 53. a rectangular box; 54. a second hanging ring; 55. a rectangular opening; 56. and a liquid discharge pipe.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present utility model more clear, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. It will be apparent that the described embodiments are some, but not all, embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The utility model is further described below with reference to examples.

In some embodiments, referring to fig. 1-8 of the specification, a lifting device for electrolysis of an acidic etching solution comprises a top plate 1,

the movable carrier assembly 2 for moving the electrolytic plate assembly 4 is arranged on the top plate 1;

the movable carrying assembly 2 comprises a rectangular sliding block 21 and a carrying box 22, wherein the rectangular sliding block 21 is in fit sliding connection with a sliding groove formed in the top plate 1, the carrying box 22 is fixedly arranged at the bottom of the rectangular sliding block 21, and the carrying box 22 is respectively connected with the hoisting assembly 3 and the liquid collecting assembly 5;

the carrying case 22 of the movable carrying case 2 is horizontally moved along the chute by the rectangular slider 21, and the hoist assembly 3 and the liquid collecting assembly 5 connected to the carrying case 22 are also moved.

The movable carrying component 2 is provided with a hoisting component 3 for hoisting the electrolytic plate component 4;

the lifting assembly 3 comprises a lifting assembly 31 and a clamping assembly 32, wherein the lifting assembly 31 is arranged in the carrying box 22, and the lifting assembly 31 is connected with the clamping assembly 32;

when the carrying case 22 moves above the electrolytic plate assembly 4, the lifting assembly 31 of the hoisting assembly 3 is started to move downwards, after moving to the corresponding position, the clamping assembly 32 is started to clamp the electrolytic plate assembly 4, the lifting assembly 31 is started to move upwards, and after the electrolytic plate assembly 4 is pulled out of the electrolytic cell, the carrying case 22 is driven to move towards the unloading area through the rectangular sliding block 21.

The lifting assembly 31 comprises a motor 311, a first gear 312, a second gear 313, a first threaded rod 314, a thread bush 315, a guide limiting rod 316 and a first rectangular plate 317, wherein the motor 311 is fixedly arranged at the inner top of the carrying box 22, the first gear 312 is fixedly arranged at the output end of the motor 311, the first threaded rod 314 is rotatably arranged at the bottom of the carrying box 22, the second gear 313 is fixedly arranged at the top of the first threaded rod 314, the second gear 313 is in meshed connection with the first gear 312, the thread bush 315 is in threaded connection with the first threaded rod 314, first rectangular plates 317 are fixedly arranged at two ends outside the thread bush 315 respectively, the guide limiting rod 316 penetrates through the first rectangular plates 317, one end of the guide limiting rod 316 is fixedly connected with the bottom of the carrying box 22, the length of the guide limiting rod 316 is the same as that of the first threaded rod 314, and one end of the first rectangular plate 317 far away from the thread bush 315 is connected with the clamping assembly 32;

the clamping assembly 32 comprises a telescopic rod 321, a first clamping plate 322, a second clamping plate 323, a movable groove 324, a rack 325, a second threaded rod 326 and a rotating assembly 327, one end of the first rectangular plate 317, which is far away from the threaded sleeve 315, is fixedly connected with the top of the telescopic rod 321, the bottom of the telescopic rod 321 is fixedly connected with the first clamping plate 322, the lower end of the first clamping plate 322 is provided with the movable groove 324, two ends of the second threaded rod 326 are respectively and rotatably connected with the inner wall of the movable groove 324, one end of the second threaded rod 326 passes through the first clamping plate 322, the rotating assembly 327 is fixedly connected with one end of the second threaded rod 326, the left and right ends of the bottom of the second clamping plate 323 are in fit sliding connection with the top of the first clamping plate 322, the bottom of the second clamping plate 323 is fixedly provided with a rack 325, the lower end of the rack 325 is in meshed connection with the second clamping plate 322, and the outer walls of the left and right sides of the rack 325 are respectively connected with the movable groove 324;

preferably, the first clamping plate 322 is L-shaped;

preferably, an anti-skid sleeve is fixedly installed on the rotating assembly 327;

when the carrying case 22 moves above the electrolytic plate assembly 4, the motor 311 of the lifting assembly 31 is started, the output end of the motor 311 drives the first gear 312 to rotate positively, the first gear 312 drives the second gear 313 to rotate, the second gear 313 drives the first threaded rod 314 to rotate, the threaded sleeve 315 drives the first rectangular plate 317 to move downwards along the guiding limit rod 316, the first rectangular plate 317 drives the first clamping plate 322 to move downwards through the telescopic rod 321 of the clamping assembly 32, after moving to the corresponding position, the electrolytic plate assembly 4 is placed on the first clamping plate 322, the second threaded rod 326 rotates through the rotating assembly 327, the rack 325 meshed with the second threaded rod 326 drives the second clamping plate 323 to move towards the first clamping plate 322, finally the electrolytic plate assembly 4 is clamped by the two clamping plates, the motor 311 is reversed, the two clamping plates drive the electrolytic plate assembly 4 to move upwards, and then the electrolytic plate assembly 4 is pulled out from the electrolytic cell, and then the carrying case 22 is driven to move towards the unloading area through the rectangular sliding block 21;

the general rope hoist can shake when moving in the carrying case 22, the utility model can not shake when hoisting the electrolytic plate assembly 4 by mutually matching the motor 311, the first gear 312, the second gear 313, the first threaded rod 314, the thread bush 315, the guide limit rod 316 and the first rectangular plate 317; the general clamping of the electrolytic plate assembly 4 is completed through the hooks, and the hooks have no limiting device, so that the electrolytic plate assembly 4 can shake on the hooks at will to influence the transportation of the electrolytic plate assembly 4.

The mobile carrier assembly 2 is provided with a liquid collecting assembly 5 for collecting electrolyte.

An electrolytic plate assembly 4 for separating out electrolytic substances is arranged on the hoisting assembly 3.

In some embodiments, referring to fig. 1-8, the liquid collecting assembly 5 includes an electric push rod 51, a round rod 52, a rectangular box 53, a second hanging ring 54, a rectangular opening 55 and a liquid discharge pipe 56, the electric push rod 51 is fixedly installed on the left and right inner walls of the carrying box 22 respectively, the output end of the electric push rod 51 is fixedly connected with one end of the round rod 52, the other end of the round rod 52 is fixedly connected with the second hanging ring 54, the second hanging ring 54 is fixedly connected with the rectangular box 53, the rectangular opening 55 is formed on the rectangular box 53, the liquid discharge pipe 56 is fixedly installed at the bottom of the rectangular box 53, a valve is fixedly installed on the liquid discharge pipe 56, and sealing devices are installed on the sides, close to each other, of the two groups of rectangular boxes 53 respectively;

when the electrolytic plate assembly 4 is lifted away from the electrolytic cell, the electric push rod 51 of the liquid collecting assembly 5 is opened, the electric push rod 51 drives the round rod 52 to retract inwards, the round rod 52 drives the rectangular boxes 53 to move inwards through the second hanging ring 54, when the two groups of rectangular boxes 53 are contacted, the lower ends of the electrolytic plate assembly 4 are just surrounded, electrolyte brought out of the electrolytic cell by the electrolytic plate assembly 4 directly flows into the rectangular boxes 53, before blanking, the valve on the liquid discharge pipe 56 is opened, electrolyte in the rectangular boxes 53 is sent into the collector, then the electric push rod 51 is controlled to push the round rod 52 outwards, the round rod 52 drives the rectangular boxes 53 to move outwards slowly, and the electrolytic plate assembly 4 is directly lifted out of the electrolytic cell through the electric push rod 51, the round rod 52, the rectangular boxes 53, the second hanging ring 54, the rectangular opening 55 and the liquid discharge pipe 56, so that the electrolyte can be continuously dropped into the ground by workers when the electrolytic plate assembly 4 is lifted out of the electrolytic cell, and the working liquid can be continuously recycled.

In some embodiments, referring to fig. 1-8, the electrolytic plate assembly 4 includes an electrolytic plate 41, a second rectangular plate 42, and a first hanging ring 43, where the electrolytic plate 41 is fixedly mounted at the lower end of the second rectangular plate 42, the lower end of the electrolytic plate 41 is located in the rectangular box 53, and the first hanging ring 43 is fixedly mounted at the left and right ends of the second rectangular plate 42, and the first hanging ring 43 is respectively in fit contact with the first clamping plate 322 and the second clamping plate 323;

the first hanging ring 43 of the electrolytic plate assembly 4 is sent between the first clamping plate 322 and the second clamping plate 323, the second threaded rod 326 is rotated through the rotating assembly 327, the second threaded rod 326 is matched with the rack 325 to enable the second clamping plate 323 to be continuously close to the first clamping plate 322, the first hanging ring 43 is tightly clamped, the motor 311 drives the first threaded rod 314 to rotate, the electrolytic plate 41 is lifted out of the electrolytic cell, and the two groups of rectangular boxes 53 are pulled towards each other through the two groups of electric push rods 51 to enable the lower ends of the electrolytic plate 41 to be completely surrounded by the rectangular boxes 53.

In a non-automatic hoisting line, the rotating assembly 327 is a crank.

On the automatic hoisting production line, the rotating assembly 327 is a servo motor, at this time, the servo motor is fixedly connected with the outer wall of the first clamping plate 322, and the driving end of the servo motor is fixedly connected with the second threaded rod 326.

The above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims (10)

1. Lifting device for acid etching solution electrolysis, including roof (1), its characterized in that:

the movable carrier assembly (2) for moving the electrolytic plate assembly (4) is arranged on the top plate (1);

a hoisting assembly (3) for hoisting the electrolytic plate assembly (4) is arranged on the movable carrying assembly (2);

an electrolytic plate assembly (4) for separating out electrolytic substances is arranged on the hoisting assembly (3);

the mobile carrier assembly (2) is provided with a liquid collecting assembly (5) for collecting electrolyte;

the liquid collection assembly (5) comprises an electric push rod (51), a round rod (52), a rectangular box (53), a second hanging ring (54), a rectangular opening (55) and a liquid discharge pipe (56), wherein the electric push rod (51) is symmetrically installed on the movable carrying assembly (2), the output end of the electric push rod (51) is fixedly connected with one end of the round rod (52), the other end of the round rod (52) is fixedly connected with the second hanging ring (54), the second hanging ring (54) is fixedly connected with the rectangular box (53), the rectangular opening (55) is formed in the rectangular box (53), the liquid discharge pipe (56) is fixedly installed at the bottom of the rectangular box (53), and sealing devices are respectively installed on one sides, close to each other, of the two groups of rectangular boxes (53).

2. The hoisting device for the electrolysis of the acidic etching solution according to claim 1, wherein the movable carrying component (2) comprises a rectangular sliding block (21) and a carrying box (22), the rectangular sliding block (21) is in fit sliding connection with a sliding groove formed in the top plate (1), the carrying box (22) is fixedly arranged at the bottom of the rectangular sliding block (21), and the carrying box (22) is respectively connected with the hoisting component (3) and the liquid collecting component (5).

3. The hoisting device for the electrolysis of the acidic etching solution according to claim 2, wherein electric push rods (51) are fixedly installed on the left and right inner walls of the carrying box (22) respectively.

4. A hoisting device for electrolysis of an acidic etching solution according to claim 3, characterized in that the hoisting assembly (3) comprises a lifting assembly (31) and a clamping assembly (32), the lifting assembly (31) is installed in the carrying case (22), and the lifting assembly (31) is connected with the clamping assembly (32).

5. The hoisting device for acidic etching solution electrolysis according to claim 4, wherein the lifting assembly (31) comprises a motor (311), a first gear (312), a second gear (313), a first threaded rod (314), a thread bushing (315), a guide limit rod (316) and a first rectangular plate (317), the motor (311) is fixedly installed at the inner top of the carrying case (22), the first gear (312) is fixedly installed at the output end of the motor (311), the first threaded rod (314) is rotatably installed at the bottom of the carrying case (22), a second gear (313) is fixedly installed at the top of the first threaded rod (314), the second gear (313) is in meshed connection with the first gear (312), the thread bushing (315) is in threaded connection with the first gear (314), the first rectangular plate (317) is fixedly installed at the two ends of the outer side of the thread bushing (315), the guide limit rod (316) penetrates through the first plate (317), one end of the guide limit rod (316) is fixedly connected with the bottom of the carrying case (22), and the first rectangular plate (317) is fixedly connected with one end of the first rectangular plate (315) away from the first rectangular plate (32).

6. The hoisting device for electrolysis of an acidic etching solution according to claim 5, wherein the length of the guiding and limiting rod (316) is the same as the length of the first threaded rod (314).

7. The hoisting device for acidic etching solution electrolysis according to claim 6, wherein the clamping assembly (32) comprises a telescopic rod (321), a first clamping plate (322), a second clamping plate (323), a movable groove (324), a rack (325), a second threaded rod (326) and a rotating assembly (327), one end of the first rectangular plate (317) far away from the threaded sleeve (315) is fixedly connected with the top of the telescopic rod (321), the bottom of the telescopic rod (321) is fixedly connected with the first clamping plate (322), the movable groove (324) is formed in the lower end of the first clamping plate (322), two ends of the second threaded rod (326) are respectively connected with the inner wall of the movable groove (324) in a rotating mode, one end of the second threaded rod (326) penetrates through the first clamping plate (322), the rotating assembly (327) is fixedly connected with one end of the second clamping plate (326), the left end and the right end of the bottom of the second clamping plate (323) are fixedly connected with the top of the first clamping plate (322) in a sliding mode, the bottom of the second clamping plate (323) is fixedly mounted with the bottom of the first clamping plate (322), two ends of the second clamping plate (326) are respectively meshed with the left end and the right end of the second threaded rod (325) in a sliding mode, and the two ends of the threaded rod (325) are respectively meshed with the inner wall of the movable groove (324).

8. The lifting device for the electrolysis of an acidic etching solution according to claim 7, wherein the first clamping plate (322) is L-shaped.

9. The hoisting device for electrolysis of acidic etching solution according to claim 8, wherein the electrolytic plate assembly (4) comprises an electrolytic plate (41), a second rectangular plate (42) and a first hanging ring (43), the electrolytic plate (41) is fixedly arranged at the lower end of the second rectangular plate (42), the first hanging ring (43) is fixedly arranged at the left end and the right end of the second rectangular plate (42), and the first hanging ring (43) is respectively in fit contact with the first clamping plate (322) and the second clamping plate (323).

10. Hoisting device for the electrolysis of acidic etching solutions according to claim 9, characterized in that the lower end of the electrolysis plate (41) is located in a rectangular box (53).