CN111749478A - A floor installation calibration and positioning device based on prefabricated building installation - Google Patents

Abstract

The invention discloses a floor slab installation, calibration and positioning device based on a prefabricated building installation, comprising a main support frame, a wall body, a fastening bolt and a prefabricated plate. The bottom end of the main support frame is connected with a clamping mechanism, and the clamping The mechanism is connected to the inside of the wall, the top of the main support frame is connected with fastening bolts, the inside of the main support frame is provided with an inner socket, one side of the knob is connected with a positioning mechanism, and the surface of the positioning mechanism is A prefabricated board is connected, the bottom end of the prefabricated board is connected with a support mechanism, and the bottom end of the support mechanism is connected with a fixing mechanism, the bottom end of the fixing mechanism is connected with a secondary support frame, and the bottom end of the secondary support frame is connected with a Reinforcement frame. The present invention can conveniently fix the prefabricated boards by setting the positioning mechanism, and the device can conveniently engage and fix the prefabricated boards by setting the engaging mechanism, thereby increasing the stability of the prefabricated boards when they are connected.

Description

A floor installation calibration and positioning device based on prefabricated building installation

technical field

The invention relates to the technical field of floor slab installation, in particular to a floor slab installation calibration and positioning device for prefabricated building installation.

Background technique

Prefabricated panels are the floor slabs used in early twentieth-century buildings, modules or slabs used in engineering. Because the prefabricated concrete parts are produced and processed in the prefabrication yard and shipped directly to the construction site for installation, so they are called prefabricated panels.

For example, the publication number: CN110528703A discloses that the present invention discloses a building embedded part, which includes a fixing part, a first connecting sleeve is fixedly arranged on a first side of the fixing part; a second side of the fixing part facing away from the first side A second connection sleeve is fixedly provided. The building embedded part of the invention can avoid drilling holes on the floor during construction, thereby improving the convenience of construction. The invention also discloses a positioning prefabricated floor slab that avoids drilling during construction, improves the convenience of construction, enhances the surface aesthetics, and has the function of being identified and positioned by a machine. For installation, but using bolts for installation will cause the prefabricated panels to be damaged by the stress of the bolts, and some existing floor panels are installed with calibration positioning devices, and the floor panels are only installed manually and relying on experience, but manual manual installation. Relying on experience to install will produce deviations, which may lead to uneven stress on the prefabricated panels during later use, which may cause some safety hazards to the floor after long-term use. Install calibration positioning devices to solve the above problems.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a floor installation calibration and positioning device based on prefabricated building installation, so as to solve the existing partial floor installation calibration and positioning device proposed in the above background technology, the floor plate does not have a fixed function, and the existing part Floor installation calibration positioning device, the floor installation may cause deviation problems.

In order to achieve the above purpose, the present invention provides the following technical solutions: a floor installation and calibration positioning device based on prefabricated building installation, including a main support frame, a wall, a fastening bolt and a prefabricated plate, and the bottom end of the main support frame is connected There is a snap mechanism, and the snap mechanism is connected to the inside of the wall, the top of the main support frame is connected with a fastening bolt, the inside of the main support frame is provided with an inner socket, and one side of the knob is connected with a a positioning mechanism, and the surface of the positioning mechanism is connected with a prefabricated plate, the bottom end of the prefabricated plate is connected with a support mechanism, and the bottom end of the support mechanism is connected with a fixing mechanism, and the bottom end of the fixing mechanism is connected with a secondary support frame, and The bottom end of the auxiliary support frame is connected with a reinforcement frame, and the bottom end of the reinforcement frame is connected with the surface of the main support frame, the outer surface of the bottom end of the main support frame is connected with a buffer block, and the inner wall of the buffer block is inserted with a buffer air bag .

Preferably, the engaging mechanism includes a first spring, a first clamping block, an inner connecting block and a first clamping cavity, the first clamping cavity is opened inside the wall, and the interior of the first clamping cavity is inserted with A first clamping block, one side of the first clamping block is connected with a first spring, and one side of the first clamping block is inserted into the surface of the inner connecting block.

Preferably, the positioning mechanism includes an arc-shaped block, an inner rod, an inner connecting hole, a first rod and a first connecting rod, one side of the knob is connected with the rod, and the inner rod of the rod is inserted An arc-shaped block is provided, one side of the arc-shaped block is hinged with a first connecting rod, and one side of the first connecting rod is hinged with a first insertion rod, and the outer surface of the arc-shaped block is abutted with a first connecting rod. The inner connecting hole is opened in the interior of the prefabricated board, the outer surface of the inner rod is connected with a snap ring, the inner rod is arranged through, and the inner rod is inserted with a rod, so The plunger is connected to one side of the first plunger.

Preferably, the support mechanism includes a lower support plate, a first threaded rod, a tray, a worm, a worm wheel, an inner support frame, a first bracket and an inner threaded ring, the bottom end of the prefabricated plate is connected with the lower support plate, and The bottom end of the lower pallet is connected with a tray through a rotating shaft, and the bottom end of the tray is connected with a first threaded rod, the bottom surface of the first threaded rod is sleeved with a first connecting cylinder, and the inner part of the first connecting cylinder is inserted An inner thread ring is provided, the outer surface of the inner thread ring is connected with a worm gear, and the bottom end of the first connection cylinder is connected with an inner support frame.

Preferably, the fixing mechanism includes a first connecting block, a second threaded rod, an inner connecting rod, an adjusting wheel and a second connecting rod, a square column is inserted inside the inner support frame, and a square column is inserted inside the square column There is a second threaded rod, one side of the second threaded rod is connected with a second connecting rod, the surface of the second connecting rod is sleeved with an inner connecting rod, and one side of the second connecting rod is connected with an adjusting wheel.

Preferably, the internal shape and size of the inner socket is adapted to the surface shape and size of the knob, the knob is inserted inside the inner socket, and the knob and the inner socket are slidingly connected.

Preferably, the surface of the first threaded rod and the inner wall of the first connecting cylinder are both provided with threads, and the first threaded rod is inserted inside the first connecting cylinder, and the first threaded rod and the first connecting cylinder are Threaded connection.

Preferably, the inner support frame is provided with a square hole, and the inner shape and size of the square hole are adapted to the surface shape and size of the square column, the square column is inserted inside the inner support frame, and the inner support The frame and the square column are snap-connected.

Preferably, the inner shape and size of the arc-shaped clamping blocks are provided with four groups, and the four groups of arc-shaped clamping blocks are hinged on the surface of the first insertion rod at equal distances.

Preferably, the inside of the square column is provided with a through groove, and the inner wall of the through groove and the surface of the second threaded rod are both provided with threads, the second threaded rod is inserted into the interior of the square column, and the second thread The rod and square column are threaded.

Compared with the prior art, the beneficial effects of the present invention are: the prefabricated board can be easily fixed by setting the positioning mechanism for the floor slab installation and calibration positioning device based on the prefabricated building installation, and the device can be easily fixed by setting the engaging mechanism. It is convenient to snap and fix the prefabricated boards and increase the stability of the prefabricated boards when they are connected.

The device is provided with a positioning mechanism, so that four sets of arc-shaped blocks are inserted into the inner connecting holes synchronously, so as to complete the fixation of the prefabricated plate, reduce the stress caused by the use of bolts for fixing the prefabricated plate, and increase the The working life of the device when it is in operation.

The device is provided with an engaging mechanism, which is placed on the surface of the wall, and the inner connecting block will be fixed inside the wall, and then the main support frame will be fixed on the surface of the wall by bolts, thereby increasing the main support The stability of the rack during installation.

Fig. 1 is the structure front sectional schematic diagram of the present invention;

2 is a schematic top view cross-sectional view of the structure of the present invention;

Fig. 3 is the structural right side sectional schematic diagram of the worm gear and the worm of the present invention;

FIG. 4 is a schematic front view cross-sectional view of the structure of the snap ring and the insert rod according to the present invention;

Fig. 5 is the left side sectional schematic diagram of the structure of the prefabricated board and the main support frame of the present invention;

6 is a schematic top view sectional view of the structure of the tray and the inner support frame of the present invention;

Fig. 7 is the structural front sectional schematic diagram of the tray and the first connecting cylinder of the present invention;

8 is an enlarged schematic view of the structure at place B in FIG. 1 of the present invention;

Fig. 9 is the left side cross-sectional schematic diagram of the structure of the arc-shaped clamping block and the insert rod according to the present invention;

Fig. 10 is the enlarged schematic diagram of the structure at C in Fig. 1 of the present invention;

11 is an enlarged schematic view of the structure at D in FIG. 6 of the present invention;

FIG. 12 is an enlarged schematic view of the structure at A in FIG. 1 of the present invention.

In the figure: 1. Main support frame; 2. Wall body; 3. Fastening bolts; 4. Knob; 5. Inner jack; 6. Prefabricated plate; 7. Lower pallet; 8. First threaded rod; 9. Auxiliary support frame; 10, Reinforcement frame; 11, Tray; 12, Worm; 13, Worm gear; 14, Inner support frame; 15, First connecting cylinder; 16, First bracket; 17, Snap ring; 18, Arc clamping block; 19, insert rod; 20, inner connecting hole; 21, buffer block; 22, first connecting block; 23, internal thread ring; 24, first insert rod; 25, first connecting rod; 26, buffer Air bag; 27, second threaded rod; 28, inner connecting rod; 29, square column; 30, adjusting wheel; 31, second connecting rod; 32, first spring; 33, first clamping block; 34, inner connecting block 35. The first card cavity.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Please refer to Figures 1-12, an embodiment provided by the present invention: a floor installation calibration and positioning device based on prefabricated building installation, including a main support frame 1, a wall body 2, fastening bolts 3 and a prefabricated plate 6, the main The bottom end of the support frame 1 is connected with an engaging mechanism, and the engaging mechanism is connected to the interior of the wall body 2, the top end of the main support frame 1 is connected with a fastening bolt 3, and the interior of the main support frame 1 is provided with an inner socket 5, The internal shape and size of the inner socket 5 is adapted to the surface shape and size of the knob 4. The knob 4 is inserted inside the inner socket 5, and the knob 4 and the inner socket 5 are slidingly connected. When the knob 4 is inserted into the inner socket 5 , the inner socket 5 limits the knob 4 to reduce the shaking generated when the knob 4 works inside the inner socket 5 .

One side of the knob 4 is connected with a positioning mechanism, and the surface of the positioning mechanism is connected with a prefabricated plate 6, the bottom end of the prefabricated plate 6 is connected with a support mechanism, and the bottom end of the support mechanism is connected with a fixing mechanism, and the bottom end of the fixing mechanism is connected with a The auxiliary support frame 9, and the bottom end of the auxiliary support frame 9 is connected with the reinforcement frame 10, and the bottom end of the reinforcement frame 10 is connected with the surface of the main support frame 1, and the outer surface of the bottom end of the main support frame 1 is connected with a buffer block 21, And the inner wall of the buffer block 21 is inserted with a buffer air bag 26 .

The engaging mechanism includes a first spring 32, a first clamping block 33, an inner connecting block 34 and a first clamping cavity 35. The first clamping cavity 35 is opened inside the wall 2, and the interior of the first clamping cavity 35 is inserted with a The first blocking block 33, one side of the first blocking block 33 is connected with the first spring 32, and one side of the first blocking block 33 is inserted into the surface of the inner connecting block 34. The installation position of the support frame 1 is positioned.

The positioning mechanism includes an arc block 18, an inner rod 19, an inner connecting hole 20, a first rod 24 and a first connecting rod 25. One side of the knob 4 is connected with the inner rod 19, and the inner part of the inner rod 19 An arc-shaped block 18 is inserted, and the inner shape and size of the arc-shaped block 18 is provided with four groups, and the four groups of arc-shaped blocks 18 are hinged on the surface of the first insertion rod 24 at equal distances. The clamping block 18 can easily expand the prefabricated board 6 inside the inner connecting hole 20 to expand, engage and fix it.

One side of the arc-shaped block 18 is hinged with a first connecting rod 25, and one side of the first connecting rod 25 is hinged with a first insertion rod 24, the outer surface of the arc-shaped block 18 is abutted with an inner connecting hole 20, and The inner connecting hole 20 is opened in the interior of the prefabricated plate 6, the outer surface of the insertion rod 19 is connected with a snap ring 17, the inner insertion rod 19 is arranged through, and an insertion rod is inserted inside the inner insertion rod 19, and the insertion rod is connected at the One side of the first plunger 24 .

The support mechanism includes a lower support plate 7, a first threaded rod 8, a tray 11, a worm 12, a worm wheel 13, an inner support frame 14, a first bracket 16 and an inner threaded ring 23. The bottom end of the prefabricated plate 6 is connected with a lower support plate 7, and the bottom end of the lower support plate 7 is connected with the tray 11 through the rotating shaft, and the bottom end of the tray 11 is connected with the first threaded rod 8, and the bottom end surface of the first threaded rod 8 is sleeved with the first connecting cylinder 15, The surface of a threaded rod 8 and the inner wall of the first connecting cylinder 15 are both provided with threads, and the first threaded rod 8 is inserted into the interior of the first connecting cylinder 15, and the first threaded rod 8 and the first connecting cylinder 15 are threadedly connected , by setting it as a threaded connection, the first threaded rod 8 can be effectively and conveniently moved up and down inside the first connecting cylinder 15 , so that the supporting height of the prefabricated plate 6 can be easily adjusted.

An inner thread ring 23 is inserted into the first connecting cylinder 15 , the outer surface of the inner thread ring 23 is connected with the worm gear 13 , and the bottom end of the first connecting cylinder 15 is connected with the inner support frame 14 .

The fixing mechanism includes a first connecting block 22, a second threaded rod 27, an inner connecting rod 28, an adjusting wheel 30 and a second connecting rod 31, a square column 29 is inserted inside the inner support frame 14, and a square column 29 is inserted inside the inner support frame 14. There is a square hole, and the internal shape and size of the square hole are matched with the surface shape and size of the square column 29. The square column 29 is inserted into the interior of the inner support frame 14, and the inner support frame 14 and the square column 29 are connected by a snap connection. The adapted shape and size can make the square column 29 more tightly inserted into the inner support frame 14 , reduce the possibility of loosening, and make the connection more tightly.

A second threaded rod 27 is inserted inside the square column 29, a through groove is opened inside the square column 29, and the inner wall of the through groove and the surface of the second threaded rod 27 are both provided with threads, and the second threaded rod 27 is inserted in. Inside the square column 29, the second threaded rod 27 and the square column 29 are threadedly connected. By setting the threaded connection, the square column 29 can be easily moved along the surface of the second threaded rod 27, so that the square column can be easily moved. 29 is inserted inside the inner support frame 14 .

One side of the second threaded rod 27 is connected to the second connecting rod 31 , the inner connecting rod 28 is sleeved on the surface of the second connecting rod 31 , and the adjusting wheel 30 is connected to one side of the second connecting rod 31 .

Working principle: When the prefabricated board 6 needs to be installed, the auxiliary support frame 9 can be manually held first, the first connecting block 22 at the top of the auxiliary support frame 9 is inserted into the inner support frame 14, and then manually rotated and adjusted wheel 30, so that the adjustment wheel 30 drives the second connecting rod 31 to rotate, and then through the connection between the second connecting rod 31 and the second threaded rod 27, the second threaded rod 27 can be rotated synchronously, and at the same time through the second threaded rod 27 The threaded structure between the rod 27 and the square column 29 is matched with the square hole inside the first connecting block 22 to limit the position, so that the square column 29 can be moved along the surface of the second threaded rod 27, so that the square column 29 is inserted into the interior of the inner support frame 14, so that the inner support frame 14 can be fixed on the top end surface of the auxiliary support frame 9, and then the worm 12 can be manually held, rotated, and passed between the worm 12 and the worm wheel 13. Meshing can easily drive the worm wheel 13 to rotate, and with the rotation of the worm wheel 13, the worm wheel 13 can drive the inner threaded ring 23 to rotate inside the first connecting cylinder 15, and then pass through the inner threaded ring 23 and the first threaded rod. The threaded structure between 8 can easily make the height position of the first threaded rod 8 rise, and cooperate with the tray 11 connected by the rotating shaft at the top of the first threaded rod 8, which can facilitate the support of the prefabricated plate 6. At the same time, when the height is After the adjustment is appropriate, the rotation of the worm 12 can be stopped, and after the rotation of the worm 12 is stopped, the thread friction force between the worm 12 and the worm wheel 13 can make it self-locking without the phenomenon of reversal. The rod 19 is inserted into the interior of the prefabricated plate 6, so that the snap ring 17 and the inner connecting hole 20 opened in the prefabricated plate 6 are engaged and fixed, and then the insertion rod inside the fastening bolt 3 can be manually rotated to make the insertion rod drive the first. The insertion rod 24 rotates, and through the rotation of the first insertion rod 24, the first insertion rod 24 can drive the first connecting rod 25 hinged on its outer surface to move synchronously, and through the movement of the first connecting rod 25, the The first connecting rod 25 pushes out the arc-shaped block 18 from the inside of the insertion rod 19, and makes the arc-shaped block 18 in the maximum stroke state inserted into the inner wall of the inner connecting hole 20, and then the plug can be pulled backward. rod 19, and then four sets of arc-shaped blocks 18 can be simultaneously inserted into the inner connecting hole 20 to complete the fixation of the prefabricated board 6, reduce the stress brought by the prefabricated board 6 when it is fixed with bolts, and increase the The working life of the device during operation.

When the main support frame 1 needs to be installed and fixed, the main support frame 1 can be placed on the surface of the wall body 2 first. When the main support frame 1 is placed on the surface of the wall body 2, the buffer block 21 will first connect with the wall body 2. The surface of the body 2 is in contact, and the impact force received is transmitted to the buffer air bag 26, so that the buffer air bag 26 is deformed, and the deformed buffer air bag 26 will fully absorb the impact force, and then the main support can be manually The top of the frame 1 is placed on the surface of the wall 2, and then the inner connecting block 34 at the bottom end of the main support frame 1 can be inserted into the interior of the wall 2. While inserting the inner connecting block 34 into the interior of the wall 2, the first A blocking block 33 will be blocked by the side wall of the inner connecting block 34. At the same time, when the inner connecting block 34 is completely inserted into the wall 2, the first spring 32 will cause the first blocking block 33 to be inserted through the elastic force. To the inside of the inner connecting block 34, the inner connecting block 34 will be fixed inside the wall body 2, and then the main support frame 1 will be fixed on the surface of the wall body 2 by bolts, so as to increase the installation of the main support frame 1. stability.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the appended claims. All changes within the meaning and range of the equivalents of , are included in the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

Claims (10)

1. A floor slab installation calibration and positioning device based on prefabricated building installation, comprising a main support frame (1), a wall (2), a fastening bolt (3) and a prefabricated plate (6), characterized in that: the main The bottom end of the support frame (1) is connected with an engaging mechanism, and the engaging mechanism is connected inside the wall body (2), the top end of the main support frame (1) is connected with a fastening bolt (3), and the main support frame (1) is connected with a fastening bolt (3). An inner socket (5) is provided inside the support frame (1), a positioning mechanism is connected to one side of the knob (4), and a prefabricated plate (6) is connected to the surface of the positioning mechanism, and the prefabricated plate (6) A support mechanism is connected to the bottom end of the support mechanism, and a fixing mechanism is connected to the bottom end of the support mechanism. 10), and the bottom end of the reinforcing frame (10) is connected to the surface of the main support frame (1), the outer surface of the bottom end of the main support frame (1) is connected with a buffer block (21), and the buffer block (21) A buffer air bag (26) is inserted into the inner wall of the . 2 . The installation and calibration positioning device based on prefabricated building installation according to claim 1 , wherein the engaging mechanism comprises a first spring ( 32 ), a first clamping block ( 33 ), an internal connection block (34) and a first clamping cavity (35), the first clamping cavity (35) is opened inside the wall (2), and a first clamping block (35) is inserted in the interior of the first clamping cavity (35). 33), one side of the first clamping block (33) is connected with a first spring (32), and one side of the first clamping block (33) is inserted into the surface of the inner connecting block (34). 3. A floor-slab installation calibration positioning device based on prefabricated building installation according to claim 1, characterized in that: the positioning mechanism comprises an arc-shaped block (18), an inner rod (19), an inner connecting hole (20), a first insertion rod (24) and a first connecting rod (25), an inner insertion rod (19) is connected to one side of the knob (4), and an inner insertion rod (19) is inserted with a An arc-shaped block (18), one side of the arc-shaped block (18) is hinged with a first connecting rod (25), and one side of the first connecting rod (25) is hinged with a first insertion rod (24) , the outer surface of the arc-shaped block (18) is abutted with an inner connecting hole (20), and the inner connecting hole (20) is opened inside the prefabricated plate (6), and the outer surface of the inner rod (19) A snap ring (17) is connected on the surface, the insertion rod (19) is provided through, and an insertion rod is inserted inside the insertion rod (19), and the insertion rod is connected to the first insertion rod (24). side. 4. A floor-slab installation, calibration and positioning device based on prefabricated building installation according to claim 1, characterized in that: the support mechanism comprises a lower support plate (7), a first threaded rod (8), a tray (11) ), a worm (12), a worm wheel (13), an inner support frame (14), a first bracket (16) and an inner thread ring (23), the bottom end of the prefabricated plate (6) is connected with a lower support plate ( 7), and the bottom end of the lower support plate (7) is connected with the tray (11) through the rotating shaft, and the bottom end of the tray (11) is connected with the first threaded rod (8), the first threaded rod (8) A first connecting cylinder (15) is sleeved on the bottom end surface, and an internal thread ring (23) is inserted into the inside of the first connecting cylinder (15), and a worm wheel (13) is connected to the outer surface of the internal thread ring (23). ), the bottom end of the first connecting cylinder (15) is connected with an inner support frame (14). 5 . The installation and calibration positioning device based on the floor slab for prefabricated building installation according to claim 1 , wherein the fixing mechanism comprises a first connecting block ( 22 ), a second threaded rod ( 27 ), an internal connection The rod (28), the adjusting wheel (30) and the second connecting rod (31), a square column (29) is inserted inside the inner support frame (14), and a second column (29) is inserted inside the square column (29). Two threaded rods (27), one side of the second threaded rod (27) is connected to the second connecting rod (31), and the surface of the second connecting rod (31) is sleeved with an inner connecting rod (28), so One side of the second connecting rod (31) is connected with an adjusting wheel (30). 6 . The floor installation and calibration positioning device based on prefabricated building installation according to claim 1 , wherein the internal shape and size of the inner socket ( 5 ) are suitable for the surface shape and size of the knob ( 4 ). 7 . The knob (4) is inserted into the inner socket (5), and the knob (4) and the inner socket (5) are slidingly connected. 7 . The floor installation and calibration positioning device for prefabricated building installation according to claim 1 , wherein the surface of the first threaded rod ( 8 ) and the inner wall of the first connecting cylinder ( 15 ) are both set There are threads, and the first threaded rod (8) is inserted into the interior of the first connecting cylinder (15), and the first threaded rod (8) and the first connecting cylinder (15) are threadedly connected. 8 . The floor installation and calibration positioning device for prefabricated building installation according to claim 1 , wherein the inner support frame ( 14 ) is provided with a square hole, and the internal shape and size of the square hole are the same as the size of the square hole. 9 . The shape and size of the surface of the square column (29) are adapted, the square column (29) is inserted into the interior of the inner support frame (14), and the inner support frame (14) and the square column (29) are in a snap-fit connection . 9 . The floor installation and calibration positioning device for prefabricated building installation according to claim 1 , characterized in that: the inner shape and size of the arc-shaped clamping block ( 18 ) is provided with four groups, and the four groups are arc-shaped. 10 . The clamping block (18) is equidistantly hinged on the surface of the first insertion rod (24). 10 . The installation and calibration positioning device for a floor slab based on prefabricated building installation according to claim 1 , characterized in that: a through slot is opened inside the square column ( 29 ), and the inner wall of the through slot and the second thread The surfaces of the rods (27) are all provided with threads, the second threaded rods (27) are inserted inside the square columns (29), and the second threaded rods (27) and the square columns (29) are threadedly connected.

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