Handheld steel bar cutting-off equipment
Through the design of handheld steel bar cutting equipment, the use of telescopic cylinder and double spring buffer, threaded rod and rubber pressure block, T-shaped connecting frame and other structures solves the cutting efficiency and safety problems of scrap steel bar processing equipment in complex sites, and achieves fast, stable and damage-free cutting effects.
Patent Information
- Application Number
- CN202510790370.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-13
- Publication Date
- 2025-09-12
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the existing technology, scrap steel bar processing equipment has the problems of being large and inconvenient to use flexibly, and manual tools are inefficient and unsafe. In particular, it is difficult to efficiently cut thick steel bars at complex demolition sites.
A handheld steel bar cutting device was designed, which adopted a telescopic cylinder and a double spring buffer device, a threaded rod and a rubber pressing block, a T-shaped connecting frame and an arc-shaped fitting structure to achieve rapid fixation of steel bars, stable cutting and flexible operation of the equipment.
It achieves rapid cutting of steel bars, damage-free fixation, improved equipment stability and operational flexibility, reduces operator vibration amplitude and equipment failure frequency, and adapts to the cutting needs of complex demolition sites.
Smart Images
Figure CN120619467A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of construction waste treatment, in particular to a handheld steel bar cutting device. Background Art
[0002] With the acceleration of urbanization, an increasing number of old town renovation projects are underway, leading to the demolition of numerous old buildings. During this demolition process, beams and columns often contain a large amount of scrap rebar. These scrap rebars are typically arranged in a cage-like pattern, which not only takes up a significant amount of storage and transportation space but also increases the cost of subsequent processing. Therefore, how to quickly and efficiently process this scrap rebar has become a pressing issue. While there are some large rebar cutting machines on the market, their bulk and inconvenience make them difficult to adapt to complex demolition site environments. Furthermore, some smaller handheld tools, while lightweight, suffer from significant shortcomings in cutting efficiency and safety.
[0003] In the existing technology, the work location needs to be changed frequently during the demolition of residential buildings. Although large fixed steel bar cutting machines have high cutting capacity and stability, they are not convenient for flexible use on site due to their large size and require special operators and site support; small manual shearing tools are light and easy to carry, suitable for single-person operation, but because they rely on human power, their work efficiency is low, long-term work can easily lead to fatigue, and thicker steel bars cannot be effectively cut; electric hydraulic shears use electric motors to drive the hydraulic system to achieve shearing action, which improves work efficiency compared to manual tools, but still has problems such as heavy weight and short battery life. It is necessary to design a handheld steel bar cutting device to solve the above-mentioned problems. Summary of the Invention
[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to provide a handheld steel bar cutting device to solve the problems in the above technical solutions.
[0005] To achieve the above object, the present invention is implemented through the following technical solutions: A handheld steel bar cutting device includes a first base and a second base, the first base is located on the left front side, the second base is located on the right rear side, the upper parts of the first base and the second base are both provided with a support unit, and the upper part of the support unit is provided with a support plate; A fixing unit is provided on the upper portion of the first base, and the fixing unit is used to press down and fix the cut steel bar to prevent it from moving during the cutting process; A pressing unit is provided on the upper portion of the second base, a connecting unit is fixedly connected to the front side of the pressing unit, a handheld cutting device is fixedly connected to the front side of the connecting unit, the pressing unit is used to assist the downward movement and movement stability of the handheld cutting device, and the connecting unit is used to connect the pressing unit and the handheld cutting device; A cutting groove is provided on the left rear portion of the support plate, and the cutting blade of the handheld cutting device is directly opposite to the cutting groove.
[0006] Furthermore, threaded seats are provided on the left and right sides of the upper parts of the first base and the second base, and the support units each include two support rods, the bottom ends of the support rods are each provided with a threaded head, and are threadedly connected to the inner side of the corresponding threaded seat; The support rods are all L-shaped, and the support plates are fixedly connected to the upper parts of the support rods.
[0007] Furthermore, the pressing unit includes a bottom plate, which is fixedly connected to the upper part of the second base, and sliding rods are fixedly provided on the left and right sides of the upper part of the bottom plate. A top plate is provided on the upper part of the sliding rod, and a telescopic cylinder is fixedly connected to the bottom of the top plate, and the telescopic end of the telescopic cylinder is fixedly connected to the lower pressing seat; A sleeve is provided in the middle of the upper end of the base plate, a first downward pressure spring is provided in the sleeve, a circular groove is provided at the bottom of the downward pressure seat, the upper end of the first downward pressure spring is provided in the circular groove, and a second downward pressure spring is provided at the outer bottom of the sliding rod.
[0008] Furthermore, a connector is provided on the upper portion of the lower pressing seat, and the connector is threadedly connected to the telescopic end of the telescopic cylinder; The four corners of the lower pressing seat are each provided with side ears, and the side ears are respectively slidably connected to the outer sides of the corresponding sliding rods.
[0009] Furthermore, the connecting unit includes a connecting frame and a fixing block, the rear end of the connecting frame is fixedly connected to the front side of the lower pressing seat, the fixing block is arranged on the rear side of the handheld cutting device, and the front side of the connecting frame is fixedly connected to the rear side of the fixing block; The connecting frame is T-shaped, the front side of the lower press seat and the rear side of the fixing block are arc-shaped, and the front and rear sides of the T-shaped connecting frame respectively match the shapes of the front side of the lower press seat and the rear side of the fixing block.
[0010] Furthermore, the fixing unit includes two connecting rods, the bottom ends of the two connecting rods are respectively fixedly connected to the left and right sides of the upper part of the first base, a fixing plate is provided on the upper part of the two connecting rods, a threaded sleeve is provided in the middle part of the fixing plate, the inner side of the threaded sleeve is threadedly connected to a threaded rod, and the bottom end of the threaded rod is fixedly connected to a rubber lower pressure block.
[0011] Furthermore, mounting holes are provided on both the left and right sides of the fixing plate, and the mounting holes are respectively fixedly connected to the upper portion of the corresponding connecting rod; The upper ends of the two connecting rods are both provided with support blocks.
[0012] In summary, the present invention provides a handheld steel bar cutting device, which has the following beneficial effects: 1. The telescopic cylinder and double-spring buffer device of the pressing unit achieve the effects of efficient and stable cutting and extended tool life. The telescopic cylinder of the pressing unit provides a constant driving force, driving the pressing seat to feed quickly along the sliding rod, and cooperates with the handheld cutting device to achieve rapid cutting of steel bars; at the same time, the first pressing spring in the casing and the second pressing spring at the bottom of the sliding rod form a double buffer, which can absorb the cutting impact force, stabilize the tool descent speed, avoid overload and chipping, and extend the tool life compared to the traditional non-buffered structure, and reduce the vibration amplitude of the operator's hand.
[0013] 2. The threaded rod and rubber pressure block device of the fixing unit achieve the effect of rapid fixation of steel bars without surface damage. The fixing unit drives the rubber pressure block to press vertically downward by rotating the threaded rod, and uses threaded transmission to achieve precise downward pressure control; the rubber pressure block provides flexible clamping force, which can not only firmly fix the steel bars in the cutting groove of the support plate, but also avoid indentation or deformation of the steel bar surface caused by traditional rigid clamping. It is particularly suitable for scrap steel recycling scenarios with high requirements for surface quality, and the fixing efficiency is improved compared with manual clamps.
[0014] 3. Through the T-shaped connecting frame and the arc-shaped fitting device of the connecting unit, the effect of efficient power transmission and improved equipment stability is achieved. The front and rear ends of the T-shaped connecting frame of the connecting unit precisely fit with the arc surfaces of the lower pressure seat and the hand-held cutting device respectively, forming a surface contact rigid connection, which increases the efficiency of the telescopic cylinder driving force transmission and eliminates the stress concentration problem of traditional point contact, ensuring that the device does not shake during the cutting process. At the same time, the arc-shaped fitting surface supports small-angle adaptive adjustment of the hand-held cutting device to meet the needs of steel bar cutting at different angles, and improves the operational flexibility of the equipment in complex demolition environments. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a schematic diagram of the front three-dimensional structure of a handheld steel bar cutting device of the present invention.
[0016] Figure 2 This is a schematic diagram of the rear three-dimensional structure of a handheld steel bar cutting device of the present invention.
[0017] Figure 3 This is a schematic diagram of the three-dimensional structure of a downward pressing unit of a handheld steel bar cutting device of the present invention.
[0018] Figure 4 This is a schematic diagram of the three-dimensional structure of a first base, a supporting unit and a fixing unit of a handheld steel bar cutting device of the present invention.
[0019] Figure 5 This is a schematic diagram of the bottom structure of the first base, the second base and the support unit of a handheld steel bar cutting device of the present invention.
[0020] Figure 6 This is a schematic diagram of the three-dimensional structure of the lower pressure seat of a handheld steel bar cutting device of the present invention.
[0021] In the figure: 1. first base; 2. second base; 3. supporting unit; 301. supporting rod; 302. threaded head; 4. supporting plate; 401. cutting groove; 5. pressing unit; 501. bottom plate; 502. sliding rod; 503. top plate; 504. pressing seat; 505. telescopic cylinder; 506. side ear; 507. sleeve; 508. first pressing spring; 509. second pressing spring; 510. connecting head; 511. circular groove; 6. connecting unit; 601. connecting frame; 602. fixing block; 7. handheld cutting device; 8. fixing unit; 801. connecting rod; 802. fixing plate; 803. mounting hole; 804. threaded sleeve; 805. threaded rod; 806. rubber pressing block; 807. support block; 9. threaded seat. DETAILED DESCRIPTION
[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0023] Example: See also Figures 1-6 As shown, the present invention provides a technical solution: a handheld steel bar cutting device, comprising a first base 1 and a second base 2, the first base 1 being located on the left front side, and the second base 2 being located on the right rear side, the upper parts of the first base 1 and the second base 2 are both provided with a support unit 3, the upper part of the support unit 3 is provided with a support plate 4, the first base 1 and the second base 2 are arranged front and back and combined with the support unit 3 to form a stable triangular support structure, the bearing capacity of the support plate 4 is increased, and it can meet the requirements of cutting Φ6-Φ20mm steel bars; the support unit 3 is connected to the threaded seat 9 through a threaded head 302, and can be quickly disassembled and folded, thereby improving the portability of the device and being suitable for operations in narrow spaces; A fixing unit 8 is provided on the upper part of the first base 1. The fixing unit 8 is used to press down and fix the cut steel bar to prevent it from moving during the cutting process. The fixing unit 8 rotates through the threaded rod 805 to drive the rubber pressing block 806 to press down, thereby achieving rapid fixing of the steel bar. The fixing force can reach 200N, and the steel bar displacement error is ≤0.5mm, thus avoiding skewed incisions caused by shaking during cutting. A pressing unit 5 is provided on the upper part of the second base 2, and a connecting unit 6 is fixedly connected to the front side of the pressing unit 5. A handheld cutting device 7 is fixedly connected to the front side of the connecting unit 6. The pressing unit 5 is used to assist the downward movement and stable movement of the handheld cutting device 7. The connecting unit 6 is used to connect the pressing unit 5 and the handheld cutting device 7. The telescopic cylinder 505 of the pressing unit 5 provides power and cooperates with the sliding rod 502 for guidance, so that the vertical feed accuracy of the handheld cutting device 7 reaches ±1mm; the T-shaped frame of the connecting unit 6 fits the curved surface, and the stress is uniform when the driving force is transmitted, which prevents the device from shaking and improves the cutting stability; A cutting groove 401 is provided on the left rear part of the support plate 4. The cutting knife of the handheld cutting device 7 is facing the cutting groove 401. The cutting groove 401 forms a positioning reference for the steel bar and cooperates with the fixing unit 8 to ensure that the cutting position error is ≤2mm. The depth of the groove body is adapted to the diameter of the steel bar. When cutting, the steel bar is embedded in the groove to avoid the risk of splashing and improve safety.
[0024] See also Figure 4 and Figure 5 As shown, threaded seats 9 are provided on the left and right sides of the upper parts of the first base 1 and the second base 2. The support units 3 each include two support rods 301. The bottom ends of the support rods 301 are provided with threaded heads 302, which are threadedly connected to the inner sides of the corresponding threaded seats 9. The threaded connection method enables the installation accuracy of the support rods 301 to reach ±0.1mm. Only a wrench is required for disassembly. It is easy for one person to operate and assemble, and is suitable for rapid deployment at different demolition sites. The support rods 301 are all L-shaped, and the support plates 4 are fixedly connected to the upper part of the support rods 301. The vertical section and the horizontal section of the L-shaped support rods 301 form a 90° rigid connection. The horizontality error of the support plate 4 is ≤0.5°, ensuring that the steel bars are placed stably and the vibration amplitude during cutting is ≤3mm, thereby improving operational comfort.
[0025] See also Figure 3 As shown, the pressing unit 5 includes a bottom plate 501, which is fixedly connected to the upper part of the second base 2, and sliding rods 502 are fixedly provided on the left and right sides of the upper part of the bottom plate 501. A top plate 503 is provided on the upper part of the sliding rod 502, and a telescopic cylinder 505 is fixedly connected to the bottom of the top plate 503. The telescopic end of the telescopic cylinder 505 is fixedly connected to the lower pressing seat 504. After the telescopic cylinder 505 is energized, the piston rod extends, pushing the lower pressing seat 504 to move downward along the sliding rod 502, driving the handheld cutting device 7 to feed and cut; after the power is cut off, the cylinder resets, driving the lower pressing seat to rise, the cylinder thrust is stable, the cutting speed is increased, and the efficiency is improved compared with manual tools. At the same time, the sliding rod 502 and the top plate 503 form a rigid guide, and the vertical error of the lower pressing seat 504 is reduced, ensuring the verticality of the cutting; A sleeve 507 is provided in the middle of the upper end of the base plate 501, and a first downward pressure spring 508 is provided in the sleeve 507. A circular groove 511 is provided at the bottom of the downward pressure seat 504, and the upper end of the first downward pressure spring 508 is provided in the circular groove 511. A second downward pressure spring 509 is provided at the outer bottom of the sliding rod 502. When the downward pressure seat 504 descends, the second downward pressure spring 509 is first compressed at the bottom of the sliding rod. After contacting the steel bar, the cylinder continues to apply pressure to compress the first downward pressure spring 508 sleeve, and the cutting impact force is absorbed by the double springs; the first downward pressure spring 508 and the second downward pressure spring 509 make the cutting process smooth, reduce the vibration amplitude of the operator's hand, and at the same time avoid the tool from breaking due to instantaneous overload, thereby extending the tool life.
[0026] See also Figure 3 and Figure 6 As shown, a connector 510 is provided on the upper portion of the lower pressing seat 504, and the connector 510 is threadedly connected to the telescopic end of the telescopic cylinder 505. The threaded connection supports the rapid replacement of the lower pressing seat 504, adapting to handheld cutting devices 7 of different specifications, improving the compatibility of the equipment, and meeting the cutting needs of multiple scenarios; Side ears 506 are provided at the four corners of the lower pressure seat 504, and the side ears 506 are respectively slidably connected to the outer side of the corresponding sliding rod 502, with a sliding fit clearance of 0.2-0.5mm, ensuring that the lower pressure seat 504 moves linearly along the sliding rod 502, and the lateral offset error is ≤0.3mm, avoiding the blade offset during cutting, resulting in the steel bar being clamped by the knife or the incision being skewed.
[0027] See also Figure 2 As shown, the connecting unit 6 includes a connecting frame 601 and a fixing block 602. The rear end of the connecting frame 601 is fixedly connected to the front side of the lower pressure seat 504. The fixing block 602 is arranged on the rear side of the handheld cutting device 7. The front side of the connecting frame 601 is fixedly connected to the rear side of the fixing block 602. The connecting frame 601 is fixed between the lower pressure seat 504 and the fixing block 602 of the handheld cutting device 7 by bolts to form a rigid connection to transmit the cylinder driving force. The rigid connection ensures that the driving force is 100% transmitted to the cutting device, without the hysteresis phenomenon of the flexible connection, the cutting response speed is improved, and the steel bars can be quickly cut. The connecting frame 601 is T-shaped, and the front side of the lower pressure seat 504 and the rear side of the fixed block 602 are arc-shaped. The front and rear sides of the T-shaped connecting frame 601 respectively match the shapes of the front side of the lower pressure seat 504 and the rear side of the fixed block 602. The arc-shaped contact surface of the T-shaped connecting frame 601 fits with the arc-shaped surfaces of the lower pressure seat 504 and the fixed block 602, and the stress is dispersed through the curved surface contact; the curved surface contact makes the stress distribution uniform, the maximum stress value is reduced, the fatigue strength of the connecting frame 601 is improved, it can withstand multiple cutting operations, and the frequency of equipment failures is reduced.
[0028] See also Figure 5As shown, the fixing unit 8 includes two connecting rods 801, the bottom ends of the two connecting rods 801 are fixedly connected to the left and right sides of the upper part of the first base 1 respectively, and a fixing plate 802 is provided on the upper part of the two connecting rods 801, and a threaded sleeve 804 is provided in the middle of the fixing plate 802. The inner side of the threaded sleeve 804 is threadedly connected to a threaded rod 805, and the bottom end of the threaded rod 805 is fixedly connected to a rubber pressing block 806. The threaded rod 805 is rotated, and the rubber pressing block 806 is moved up and down through the transmission of the threaded sleeve 804 to tighten or loosen the steel bar; the threaded transmission has high precision and can accurately control the amount of pressure. The rubber pressing block 806 provides a flexible fixing force, which can not only fix the steel bar but also avoid damaging the surface.
[0029] See also Figure 4 As shown, mounting holes 803 are provided on both the left and right sides of the fixing plate 802. The mounting holes 803 are respectively fixedly connected to the upper part of the corresponding connecting rod 801. The mounting holes 803 and the connecting rod 801 are interference fit. The fixing plate 802 is fixed by bolts to ensure its horizontal stability. The interference fit has high precision, and the horizontal error of the fixing plate 802 is reduced, so that the threaded rod 805 is pressed vertically downward to avoid uneven fixing force caused by tilting. A support block 807 is provided at the upper end of the two connecting rods 801. The top surface of the support block 807 supports the fixed plate 802 and shares the reaction force when the threaded rod 805 is pressed downward; the support block 807 increases the force-bearing area, reduces the compressive stress at the upper end of the connecting rod 801, avoids local deformation, and extends the service life of the fixed unit 8.
[0030] Working principle: First, the handheld cutting device 7 is connected and fixed to the pressing unit through the connecting unit 6, the front end of the connecting frame 601 is fixed to the fixing block 602 fixed to the rear end of the handheld cutting device 7, the rear end of the connecting frame 601 is fixed to the front side of the pressing seat 504, and the cutting blade of the handheld cutting device 7 is aligned with the upper part of the cutting groove 401, and then the steel bar to be cut is placed in the cutting groove 401 position on the left side of the upper part of the support plate 4, and the threaded rod 805 is rotated on the inner side of the threaded sleeve 804 to move the rubber pressing block 806 downward to cut the steel bar to be cut. The cut steel bars are pressed down and fixed, and then the telescopic cylinder 505 is used to push the lower pressure seat 504 downward, so that the side ears 506 set on the left and right sides of the lower pressure seat 504 slide downward on the outside of the sliding rod 502, and at the same time compress the first downward pressure spring 508 and the second downward pressure spring 509. The elastic force of the first downward pressure spring 508 and the second downward pressure spring 509 reduces the downward movement speed of the handheld cutting device 7 and increases the movement stability. Finally, after cutting the steel bars, the rubber downward pressure block 806 is released, and the telescopic cylinder 505 is used again to drive the lower pressure seat 504 to move upward and reset.
[0031] The above description is merely a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any person skilled in the art may utilize the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes for application in other fields. However, any simple modification, equivalent change, and modification of the above embodiments made in accordance with the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.
Claims
1. A handheld steel bar cutting device, comprising a first base (1) and a second base (2), characterized in that: The first base (1) is located on the left front side, and the second base (2) is located on the right rear side. The upper parts of the first base (1) and the second base (2) are both provided with support units (3), and the upper parts of the support units (3) are provided with support plates (4). A fixing unit (8) is provided on the upper portion of the first base (1), and the fixing unit (8) is used to press down and fix the cut steel bar to prevent movement during the cutting process; A pressing unit (5) is provided on the upper portion of the second base (2); a connecting unit (6) is fixedly connected to the front side of the pressing unit (5); a handheld cutting device (7) is fixedly connected to the front side of the connecting unit (6); the pressing unit (5) is used to assist the handheld cutting device (7) in moving downward and stabilizing the movement; and the connecting unit (6) is used to connect the pressing unit (5) and the handheld cutting device (7); A cutting groove (401) is provided at the rear left side of the support plate (4), and the cutting blade of the handheld cutting device (7) is positioned opposite to the cutting groove (401).
2. The handheld steel bar cutting device according to claim 1, characterized in that: Threaded seats (9) are provided on the left and right sides of the upper parts of the first base (1) and the second base (2); the support units (3) each include two support rods (301); the bottom ends of the support rods (301) are each provided with a threaded head (302) which is threadedly connected to the inner side of the corresponding threaded seat (9); The support rods (301) are all L-shaped, and the support plates (4) are fixedly connected to the upper parts of the support rods (301).
3. The handheld steel bar cutting device according to claim 1, characterized in that: The pressing unit (5) comprises a bottom plate (501), the bottom plate (501) is fixedly connected to the upper part of the second base (2), sliding rods (502) are fixedly provided on the left and right sides of the upper part of the bottom plate (501), a top plate (503) is provided on the upper part of the sliding rod (502), a telescopic cylinder (505) is fixedly connected to the bottom of the top plate (503), and a telescopic end of the telescopic cylinder (505) is fixedly connected to the pressing seat (504); A sleeve (507) is provided at the middle of the upper end of the base plate (501), a first downward pressure spring (508) is provided in the sleeve (507), a circular groove (511) is provided at the bottom of the downward pressure seat (504), the upper end of the first downward pressure spring (508) is provided in the circular groove (511), and a second downward pressure spring (509) is provided at the outer bottom of each sliding rod (502).
4. The handheld steel bar cutting device according to claim 3, characterized in that: A connector (510) is provided on the upper portion of the lower pressing seat (504), and the connector (510) is threadedly connected to the telescopic end of the telescopic cylinder (505); Side ears (506) are provided at the four corners of the lower pressing seat (504), and the side ears (506) are respectively slidably connected to the outer sides of the corresponding sliding rods (502).
5. The handheld steel bar cutting device according to claim 3, characterized in that: The connecting unit (6) comprises a connecting frame (601) and a fixing block (602), wherein the rear end of the connecting frame (601) is fixedly connected to the front side of the lower pressing seat (504), the fixing block (602) is arranged on the rear side of the handheld cutting device (7), and the front side of the connecting frame (601) is fixedly connected to the rear side of the fixing block (602); The connecting frame (601) is T-shaped, the front side of the lower pressing seat (504) and the rear side of the fixing block (602) are arc-shaped, and the front and rear sides of the T-shaped connecting frame (601) respectively match the shapes of the front side of the lower pressing seat (504) and the rear side of the fixing block (602).
6. The handheld steel bar cutting device according to claim 1, characterized in that: The fixing unit (8) comprises two connecting rods (801), the bottom ends of the two connecting rods (801) are fixedly connected to the left and right sides of the upper part of the first base (1), respectively; a fixing plate (802) is provided on the upper part of the two connecting rods (801); a threaded sleeve (804) is provided in the middle part of the fixing plate (802); the inner side of the threaded sleeve (804) is threadedly connected to a threaded rod (805); and the bottom end of the threaded rod (805) is fixedly connected to a rubber lower pressure block (806).
7. The handheld steel bar cutting device according to claim 6, characterized in that: The left and right sides of the fixing plate (802) are both provided with mounting holes (803), and the mounting holes (803) are respectively fixedly connected to the upper parts of the corresponding connecting rods (801); The upper ends of the two connecting rods (801) are both provided with support blocks (807).