阅读说明：本技术 附着式升降脚手架竖向主框架及其内、外立杆组件 (Vertical main frame of attached lifting scaffold and inner and outer upright rod assemblies thereof ) 是由 王化峰 于 2020-06-24 设计创作，主要内容包括：本发明公开了附着式升降脚手架竖向主框架,包括外立杆组件、内立杆组件、横跨杆和支撑杆；外立杆组件是由外立杆、外立补强杆和横连杆组成的双杆结构,在外立杆的外侧增加外立补强杆,外立杆与外立补强杆之间通过横连杆连接；内立杆组件为三角形结构,内立杆组件包括内立杆和双轨道杆,双轨道杆之间连接有若干横梁,横梁的两端与内立杆之间连接有侧拉杆,使得内立杆组件俯视呈三角形；相邻的外立杆之间连接横跨杆,相邻的内立杆之间也连接横跨杆；相邻的内立杆和外立杆之间连接支撑杆。本发明还公开了应用于附着式升降脚手架竖向主框架的外立杆组件和内立杆组件。本发明可以强化结构,避免变形,减小应力,提高安全性。(The invention discloses a vertical main frame of an attached lifting scaffold, which comprises an outer upright rod assembly, an inner upright rod assembly, a cross rod and a support rod; the outer vertical rod component is a double-rod structure consisting of an outer vertical rod, an outer vertical reinforcing rod and a transverse connecting rod, the outer vertical reinforcing rod is additionally arranged on the outer side of the outer vertical rod, and the outer vertical rod is connected with the outer vertical reinforcing rod through the transverse connecting rod; the inner vertical rod assembly is of a triangular structure and comprises an inner vertical rod and double-track rods, a plurality of cross beams are connected between the double-track rods, and side pull rods are connected between the two ends of the cross beams and the inner vertical rod, so that the inner vertical rod assembly is triangular when viewed from above; a cross rod is connected between the adjacent outer vertical rods, and a cross rod is also connected between the adjacent inner vertical rods; and a support rod is connected between the adjacent inner vertical rod and the outer vertical rod. The invention also discloses an outer vertical rod assembly and an inner vertical rod assembly applied to the vertical main frame of the attached lifting scaffold. The invention can strengthen the structure, avoid deformation, reduce stress and improve safety.)

1. Vertical main frame of inserted lift scaffold, its characterized in that: comprises an outer vertical rod component, an inner vertical rod component, a cross rod and a supporting rod; the outer vertical rod component is a double-rod structure consisting of an outer vertical rod, an outer vertical reinforcing rod and a transverse connecting rod, the outer vertical reinforcing rod is additionally arranged on the outer side of the outer vertical rod, and the outer vertical rod is connected with the outer vertical reinforcing rod through the transverse connecting rod; the inner vertical rod assembly is of a triangular structure and comprises an inner vertical rod and double-track rods, a plurality of cross beams are connected between the double-track rods, and side pull rods are connected between the two ends of the cross beams and the inner vertical rod, so that the inner vertical rod assembly is triangular when viewed from above; a cross rod is connected between the adjacent outer vertical rods, and a cross rod is also connected between the adjacent inner vertical rods; and a support rod is connected between the adjacent inner vertical rod and the outer vertical rod.

2. The outer pole setting subassembly of the vertical main frame of inserted lift scaffold, its characterized in that: the double-rod structure is composed of an outer vertical rod, an outer vertical reinforcing rod and a transverse connecting rod, the outer vertical reinforcing rod is additionally arranged on the outer side of the outer vertical rod, and the outer vertical rod is connected with the outer vertical reinforcing rod through the transverse connecting rod.

3. The outer pole assembly of the attached lifting scaffold vertical main frame of claim 2, wherein: the outer vertical reinforcing rod is parallel to the outer vertical rod in the area with the maximum pressure, and the upper end and the lower end of the outer vertical reinforcing rod outside the area with the maximum pressure are inclined towards the outer vertical rod and are directly connected to the outer vertical rod; or, the outer vertical reinforcing rod is arc-shaped, and the upper end and the lower end of the outer vertical reinforcing rod are directly connected to the outer vertical rod.

4. The outer pole assembly of the attached lifting scaffold vertical main frame of claim 3, wherein: the upper end of the outer vertical reinforcing rod is connected to an outer vertical rod at a guardrail at the top of the scaffold.

5. The outer pole assembly of the attached lifting scaffold vertical main frame of claim 2, wherein: the outer vertical reinforcing rods are always parallel to the outer vertical rods.

6. The outer pole assembly of the attached lifting scaffold vertical main frame of claim 2, wherein: the transverse connecting rods are rod pieces arranged in parallel; or the transverse connecting rods are rod pieces which are arranged in a staggered and inclined mode.

7. The interior pole setting subassembly of the vertical main frame of inserted lift scaffold, its characterized in that: the inner vertical rod component is of a triangular structure and comprises an inner vertical rod and double-track rods, a plurality of cross beams are connected between the double-track rods, and side pull rods are connected between the two ends of the cross beams and the inner vertical rod, so that the inner vertical rod component is triangular when overlooking.

8. The inner pole assembly of the attached lifting scaffold vertical main frame of claim 7, wherein: the horizontal plane is connected with the side pull rod between the two ends of the cross beam and the inner vertical rod, the inclined plane is also connected with the side pull rod between the two ends of the cross beam and the inner vertical rod, the side pull rods are arranged in a positive and negative staggered Z shape during side view, and the span of the inclined plane is two to four cross beams.

9. The inner pole assembly of the attached lifting scaffold vertical main frame of claim 7, wherein: the inner vertical rod is a square tube or a rectangular tube, the double-track rod is a round tube, the cross beam and the side pull rod are solid round rods, one end of the side pull rod is connected to the side length of the inner side of the inner vertical rod, and the other end of the side pull rod is connected to the joint of the cross beam and the double-track rod.

10. The inner pole assembly of the attached lifting scaffold vertical main frame of claim 7, wherein: the track groove of the wall-attached support of the scaffold is coated on the double-track rod, the notch of the track groove is used for the side pull rod to pass through, and a movement gap is reserved between the notch of the track groove and the side pull rod.

Technical Field

The invention relates to the technical field of an attached lifting scaffold, in particular to an improved structure of a vertical main frame of the attached lifting scaffold, and an inner vertical rod assembly and an outer vertical rod assembly applied to the improved structure.

Background

The attached lifting scaffold is a novel scaffold which is rapidly developed at the beginning of the century, is erected at a certain height and is attached to an engineering structure, depends on lifting equipment and a device of the attached lifting scaffold, can climb or descend along with an engineering structure layer by layer, is shown in figure 1 and figure 2, changes high-altitude operation into low-altitude operation, changes suspended operation into support body internal operation, and has the characteristics of obvious low carbon property, high-tech content, economy, safety, convenience and the like. However, recent researches find that the existing attached lifting scaffold has the problem of mechanical safety, mechanical analysis and verification are carried out according to the load specified by the JG/T546-2019 standard, the conclusion is that most products are far from meeting the requirements of the national standard JG/T546-2019, and the main problems are concentrated on the inner vertical rod assembly 100 and the outer vertical rod 202.

As shown in fig. 1 to 3, taking a 13.5 m high-attachment lifting scaffold for a typical residential building as an example, an outer vertical rod 200 of a conventional attachment lifting scaffold is of a single-rod structure, the outer vertical rod 200 is located at the outer side of the scaffold, a cross rod 700 is connected between adjacent outer vertical rods 200, and the outer vertical rods 200 are used for installing a mesh 400 to play a role in protection. Interior pole setting subassembly 100 is T type structure, interior pole setting subassembly 100 includes interior pole setting 110 and double track rail pole 120, interior pole setting 110 is located the inboard of scaffold frame, also connect horizontal cross-arm 700 between the adjacent interior pole setting 200, be connected with a plurality of crossbeams 130 between the double track rail pole 120, double track rail pole 120 is assembled on attaching wall support 500 with the liftable mode, be connected with a plurality of tie rods 140 and oblique pull rod 150 between interior pole setting 110 and the crossbeam 130, all tie rods 140 and oblique pull rod 150 are located the coplanar, it is the T type to make interior pole setting subassembly 100 overlook. A supporting rod 800 in a Z shape, a triangle shape or other shapes is connected between the adjacent inner vertical rod 110 and the outer vertical rod 200, the walkway plates 300 are laid on the adjacent crossing rod 700 and the supporting rod 800, and a step height is formed between the upper and the lower walkway plates 300. The lifting mechanism 600 drives the double-track rod 120 to slide on the wall-attached support 500, so that the whole scaffold is lifted or lowered.

In order to highlight the safety problem caused by stress, the wind direction shown by the arrow in fig. 2 is taken as an example for explanation, at this time, the outer vertical rod 200 is applied with an outward pressure, and the maximum pressure area is at the section a, namely three step-up positions below the guardrail L at the top of the scaffold; the maximum pressure concentration points of the inner vertical rod assembly 100 under the outward pulling force are the sections B and C, i.e. the second step-up position at the top and the second step-up position at the bottom of the scaffold, and the maximum stress occurs at the position D of the connection of the cross beam 130 with the drag link 140 and the diagonal draw bar 150. The existing inner vertical rod assembly 100 and the outer vertical rod assembly 200 have the potential safety hazard of bending deformation, breaking and even collapsing of the scaffold.

In view of the above, the present inventors have conducted extensive studies to improve the structure of the existing scaffold and design a vertical main frame of an attached lifting scaffold with an improved structure.

Disclosure of Invention

The invention aims to provide an improved structure of a vertical main frame of an attached lifting scaffold, and provides an inner vertical rod assembly and an outer vertical rod assembly applied to the improved structure so as to strengthen the structure, avoid deformation, reduce stress and improve safety.

In order to achieve the above purpose, the solution of the invention is:

the vertical main frame of the attached lifting scaffold comprises an outer upright rod assembly, an inner upright rod assembly, a cross rod and a support rod; the outer vertical rod component is a double-rod structure consisting of an outer vertical rod, an outer vertical reinforcing rod and a transverse connecting rod, the outer vertical reinforcing rod is additionally arranged on the outer side of the outer vertical rod, and the outer vertical rod is connected with the outer vertical reinforcing rod through the transverse connecting rod; the inner vertical rod assembly is of a triangular structure and comprises an inner vertical rod and double-track rods, a plurality of cross beams are connected between the double-track rods, and side pull rods are connected between the two ends of the cross beams and the inner vertical rod, so that the inner vertical rod assembly is triangular when viewed from above; a cross rod is connected between the adjacent outer vertical rods, and a cross rod is also connected between the adjacent inner vertical rods; and a support rod is connected between the adjacent inner vertical rod and the outer vertical rod.

The outer upright rod component of the vertical main frame of the attached lifting scaffold is a double-rod structure consisting of an outer upright rod, an outer upright reinforcing rod and a transverse connecting rod, the outer upright reinforcing rod is additionally arranged on the outer side of the outer upright rod, and the outer upright rod is connected with the outer upright reinforcing rod through the transverse connecting rod.

The interior pole setting subassembly of the vertical main frame of inserted lift scaffold is the triangle-shaped structure, and interior pole setting subassembly includes interior pole setting and double track railway pole, is connected with a plurality of crossbeams between the double track railway pole, is connected with the side pull rod between the both ends of crossbeam and the interior pole setting for interior pole setting subassembly overlooks and is triangle-shaped.

The concrete form of the external vertical reinforcing rod is as follows: the outer vertical reinforcing rod is always parallel to the outer vertical rod. Or the outer vertical reinforcing rod is parallel to the outer vertical rod in the area with the maximum pressure, and the upper end and the lower end of the outer vertical reinforcing rod outside the area with the maximum pressure are inclined towards the outer vertical rod and are directly connected to the outer vertical rod; or the outer vertical reinforcing rod is arc-shaped, and the upper end and the lower end of the outer vertical reinforcing rod are directly connected to the outer vertical rod. Furthermore, the upper end of the outer vertical reinforcing rod is connected to the outer vertical rod at the guardrail at the top of the scaffold.

The transverse connecting rods are rod pieces arranged in parallel or rod pieces arranged in a staggered and inclined mode.

The horizontal plane is connected with the side pull rod between the two ends of the cross beam and the inner vertical rod, the inclined plane is also connected with the side pull rod between the two ends of the cross beam and the inner vertical rod, the side pull rods are arranged in a positive and negative staggered Z shape during side view, and the span of the inclined plane is two to four cross beams.

The inner vertical rod is a square tube or a rectangular tube, the double-track rod is a round tube, the cross beam and the side pull rod are solid round rods, one end of the side pull rod is connected to the side length of the inner side of the inner vertical rod, and the other end of the side pull rod is connected to the joint of the cross beam and the double-track rod.

The track groove of the wall-attached support of the scaffold is coated on the double-track rod, the notch of the track groove is used for the side pull rod to pass through, and a movement gap is reserved between the notch of the track groove and the side pull rod.

After adopting the scheme, compared with the prior art, the invention has the following advantages:

the outer vertical rod component with the double-rod structure is adopted to replace the existing outer vertical rod with the single-rod structure, so that the structure of the outer vertical rod is strengthened, the wind resistance strength is improved, the deformation is avoided, the stress is reduced, and the structural safety of the outer vertical rod is greatly improved;

and the triangular inner vertical rod assembly is adopted to replace the existing T-shaped inner vertical rod assembly, the triangular stable structure is utilized, the structure of the inner vertical rod is strengthened, the deformation is avoided, the stress and the deflection are reduced, the wind resistance strength is improved, and the structural safety of the inner vertical rod is greatly improved.

The invention is described in further detail below with reference to the figures and the embodiments.

Drawings

Fig. 1 is a perspective view of a conventional attachment type lifting scaffold;

fig. 2 is a side view of a conventional attached lifting scaffold;

fig. 3 is a schematic view of an inner upright assembly of a prior art attached lifting scaffold;

FIG. 4 is a schematic perspective view of the present invention;

FIG. 5 is a side view of the present invention;

FIG. 6 is a partial top view of the present invention;

figure 7 is a schematic view of the outer pole assembly of the present invention in a second configuration;

figure 8 is a schematic view of the outer pole assembly configuration of the present invention;

figure 9 is a fourth schematic view of the outer pole assembly configuration of the present invention;

figure 10 is a five schematic view of the outer pole assembly configuration of the present invention;

figure 11 is a six-way schematic view of the outer pole assembly configuration of the present invention;

figure 12 is a schematic view of the inner vertical rod assembly of the present invention;

figure 13 is a top view of the inner vertical rod assembly configuration of the present invention;

figure 14 is a schematic view of the inner upright assembly of the present invention in cooperation with a wall attachment bracket;

figure 15 is a schematic view of the inner vertical rod assembly of the present invention in a second configuration;

figure 16 is a side elevational view of the inner leg assembly configuration of the present invention;

figure 17 is a rear elevational view of the inner vertical rod assembly configuration of the present invention;

figure 18 is a side elevational view of the present invention in a second configuration employing an inner leg assembly;

figure 19 is a side view of the instant invention in the form of an inner leg assembly;

figure 20 is a top view of the inner vertical rod assembly of the present invention in two different configurations;

figure 21 is a top view of the inner vertical rod assembly configuration of the present invention.

Description of the reference symbols

The wall-mounted type double-rail road building system comprises an inner vertical rod assembly 100, an inner vertical rod 110, a double-rail rod 120, a cross beam 130, a straight pull rod 140, a diagonal pull rod 150, an outer vertical rod 200, a walkway plate 300, a net piece 400, a wall-attached support 500, a lifting mechanism 600, a cross rod 700 and a support rod 800;

the wall-mounted type double-rail track-laying device comprises an outer vertical rod 1, an outer vertical reinforcing rod 2, a transverse connecting rod 3, an inner vertical rod assembly 4, an inner vertical rod 41, a double-rail track rod 42, a cross beam 43, a side pull rod 44, a wall-attached support 5, a track groove 51, a track board 6, a crossing rod 7 and a support rod 8.

Detailed Description

Referring to fig. 4 to 21, the present invention discloses an improved structure of a vertical main frame of an attached lifting scaffold, which includes an outer vertical rod assembly, an inner vertical rod assembly 4, a cross rod 7 and a support rod 8. This improvement is mainly found in the outer mast 1 and the inner mast assembly 4.

The improvement is as follows: the outer vertical rod component is a double-rod structure consisting of an outer vertical rod 1, an outer vertical reinforcing rod 2 and a transverse connecting rod 3. An outer vertical reinforcing rod 2 is additionally arranged on the outer side of the outer vertical rod 1, and the outer vertical rod 1 and the outer vertical reinforcing rod 2 are connected through a transverse connecting rod 3. The optimal distance between the outer vertical rod 1 and the outer vertical reinforcing rod 2 is 1/3-2/3 of the distance between the outer vertical rod 1 and the inner vertical rod 41, and the specific distance can be determined according to the actual structure and form of the scaffold.

The concrete form of the external reinforcing bar 2 can be as shown in the figure, but is not limited to the structure shown in the figure: as shown in fig. 4, 5 and 7, the outer upright reinforcement rod 2 is parallel to the outer upright 1 in the maximum pressure area (the second step-up position below the top guardrail of the scaffold), and the two ends of the outer upright reinforcement rod 2 outside the maximum pressure area are inclined towards the outer upright 1 and are directly connected to the outer upright 1, or as shown in fig. 7, the upper end of the outer upright reinforcement rod 2 also extends upwards and is directly connected to the outer upright 1 at the top guardrail of the scaffold; as shown in fig. 8 and 9, the outer vertical reinforcing rods 2 are always parallel to the outer vertical rods 1; or the outer vertical reinforcing rod 2 is not parallel to the outer vertical rod 1, for example, as shown in fig. 10 and 11, the outer vertical reinforcing rod 2 is arc-shaped, the upper end and the lower end of the outer vertical reinforcing rod 2 are directly connected to the outer vertical rod 1, and further, the upper end of the arc-shaped outer vertical reinforcing rod 2 can also be connected to the outer vertical rod 1 at the top guardrail of the scaffold like in fig. 7; of course, the external reinforcing bar 2 may take other forms. The transverse connecting rods 3 may be parallel rods as shown in fig. 4, 5, 8, and 10, or non-parallel rods, or alternatively, the transverse connecting rods 3 may be alternatively inclined rods as shown in fig. 7, 9, and 11 (i.e., the transverse connecting rods 3 are inclined outward, inclined inward, and alternate from top to bottom), or may be in other forms capable of connecting the outer upright rods 1 and the outer upright reinforcement rods 2, which are not illustrated. Moreover, the various forms of the outer vertical reinforcing rod 2 and the various forms of the transverse connecting rod 3 can be combined as required, so that the purposes of reinforcing the structure of the outer vertical rod 1 and improving the safety can be achieved.

The second improvement is that: the inner vertical rod assembly 4 is of a triangular structure, the inner vertical rod assembly 4 comprises an inner vertical rod 41 and double-track rails 42, a plurality of cross beams 43 are connected between the double-track rails 42, and side pull rods 44 are connected between two ends of the cross beams 43 and the inner vertical rod 41, so that the inner vertical rod assembly 4 is triangular when viewed from top.

The side tie bars 44 may be specifically arranged as shown in the figure, the side tie bars 44 are connected between the two ends of the cross beam 43 and the inner vertical rod 41 on a horizontal plane, the side tie bars 44 are also connected between the two ends of the cross beam 43 and the inner vertical rod 41 on an inclined plane, and in side view, the side tie bars 44 are arranged in a front-back staggered Z-shape, and the inclined plane has a span of two to four cross beams (for example, three cross beams 43 are spanned in fig. 9, 12 and 19, and two cross beams 43 are spanned in fig. 3, 15 and 18). Therefore, the triangular structure is adopted between the inner vertical rod 41 and the double-track rod 42 of the inner vertical rod assembly 4 not only on the horizontal plane but also on the inclined plane, a triangular combination body is formed on the whole three-dimensional space, and the structure is more stable.

The specific structure of the inner vertical rod assembly 4 shown in the figures is that the inner vertical rod 41 adopts a square pipe (fig. 13 and 14) or a long square pipe (fig. 20 and 21), the double-track rod 42 is a circular pipe, the cross beam 43 and the side pull rod 44 are solid circular rods, one end of the side pull rod 44 is connected to the inner side edge of the square pipe or the long square pipe of the inner vertical rod 41, and the other end of the side pull rod 44 is connected to the connection position of the cross beam 43 and the double-track rod 42. When the rail groove 51 of the wall-attached support 5 of the scaffold is coated on the double-rail rod 42, the notch of the rail groove 51 is used for the side pull rod 44 to pass through, and a movement gap is reserved between the notch of the rail groove 51 and the side pull rod 44, so that the side pull rod 44 does not influence the matching of the double-rail rod 42 and the rail groove 51, and the normal lifting of the scaffold is ensured.

The invention adopts the outer upright component with a double-rod structure to replace the existing outer upright with a single-rod structure, takes 50 x 3 as an example of an outer upright 1 of a certain type of product, and has the foundation wind pressure of 0.5KN/m²In the area (2), the maximum equivalent stress of the unmodified outer vertical rod 200 is 310MPa, the maximum stress of the modified outer vertical rod assembly of the invention is less than 150MPa, and the allowable stress of common steel is 205MPa, so that the invention strengthens the structure of the outer vertical rod, and the maximum stress of the outer vertical rod is reduced by more than 50%.

The invention adopts the triangular inner vertical rod component 4 to replace the prior T-shaped inner vertical rod component, takes the figures 3 and 9 as examples to carry out stress analysis and comparison, and has the constraint conditions as follows: two ends are hinged; length 2.1m, force: equipartition load 2KN/m, the square pipe of interior pole setting 41: 50 × 3, round tube of the double-track rod 42: Φ 48 × 3.5 (diameter 48, thickness 3.5), round steel of the cross beam 43 and side tie bar 44: Φ 25 (solid). Under the condition that the conditions are the same, the deflection stress calculated according to the finite element is compared:

	maximum deflection (mm)	Maximum stress (MPa)
			Before improvement (fig. 3)	0.297	42.7
After improvement (fig. 9)	0.200	12.2

It can be seen that the maximum stress is reduced to one fourth of the original stress after the improvement of the invention, and the maximum deflection is also reduced by nearly half. In addition, the maximum stress of the structure before improvement occurs at the position D of the connecting part of the cross beam 130, the straight pull rod 140 and the diagonal pull rod 150, the structure is unreasonable, the invention utilizes the stable structure of the triangle, the maximum stress after improvement occurs at three vertexes of the triangle, and the structure is more reasonable. In addition, the improved structure, the cross beam 43 and the side pull rod 44 can be made of round steel with the diameter of 20 or even smaller, the weight is lighter, and the strength and rigidity requirements can be still met.

In the attached lifting scaffold, the adjacent outer vertical rods 1 are connected with the cross rods 7, and the adjacent inner vertical rods 41 are also connected with the cross rods 7; a supporting rod 8 is connected between the adjacent inner vertical rod 41 and the outer vertical rod 1, and a walkway plate 6 is paved on the adjacent crossing rod 7 and the supporting rod 8. Other structures of the attached lifting scaffold of the present invention can be shown in the drawings or other forms besides the drawings, and are not described herein for the improvement of the present invention.

When the present invention employs a triangular inner leg assembly 4, the side ties 44 preferably span two beams on the incline. Taking a 13.5-meter high-attachment lifting scaffold as an example, as shown in fig. 15 to 18, at this time, the distance d1 between two adjacent crossbeams 43 of the inner vertical rod assembly 4 is 125mm, the distance d2 between two adjacent horizontal side pull rods 44 is 250mm, the distance d6 between the inner vertical rod 41 and the crossbeams 43 is 180mm, and the height d3 of the supporting rod 8 is 500mm, so that the nodes of the supporting rod 8 are exactly overlapped with the nodes of the horizontal side pull rods 44 of the inner vertical rod assembly 4, thereby ensuring that the nodes are in one-to-one correspondence and the structure is more stable. If the span of the side pull rod 44 on the inclined plane is designed into three cross beams as shown in fig. 12 and fig. 19, the distance d4 between two adjacent cross beams 43 of the inner vertical rod assembly 4 is 100mm, the distance d5 between two adjacent horizontal side pull rods 44 is 300mm, and the height d3 of the support rod 8 is 500mm, so that the node of the support rod 8 cannot coincide with the node of the horizontal side pull rod 44 of the inner vertical rod assembly 4, the nodes cannot correspond to each other, and the local stress of the connection point of the inner vertical rod 41 increases greatly, thereby bringing about a safety hazard. Furthermore, since the distance d1 between two adjacent beams 43 shown in fig. 15 to 18 is longer than the distance d4 between two adjacent beams 43 shown in fig. 12 and 19, and the total number of beams 43 shown in fig. 15 to 18 is smaller than that shown in fig. 12 and 19, although the span of the side ties 44 on the inclined plane is set to two beams as shown in fig. 15 to 18, and the span of the side ties 44 on the inclined plane is designed to three beams as shown in fig. 12 and 19, the overall weight of the attached lifting scaffold is not changed much, and the structure is more reasonable.

In addition, the optimized design of the inner vertical rod 41 of the invention adopts a rectangular tube (fig. 20 and 21), and the rectangular tube of the inner vertical rod 41: 70 × 50 × 5, round tube of the double track rod 42: phi 48 is 3.5, the sectional area of the long square tube of the inner vertical rod 41 is almost equal to that of the two circular tubes of the double-track rod 42, so that the center of the inner vertical rod component 4 is superposed with the center of gravity, the inertia moment and the section coefficient are increased when the materials are the same, the deformation resistance is enhanced, and the stress is reduced.

The above description is only exemplary of the present invention and should not be construed as limiting the scope of the present invention. It should be noted that after reading this description, those skilled in the art can make equivalent changes according to the design concept of the present application, which fall within the protection scope of the present application.