Pre-fabricated grid beam hoisting tool

Abstract

The utility model discloses a prefabricated grid beam hoisting tool, include: including hoist main part, lock tongue, compression spring and adjusting bolt, hoist main part has the vertical connecting rod and horizontal insertion rod, the connecting rod top is equipped with the crane connecting ring, the insertion rod is used for inserting the lifting hole of prefabricated grid beam, the insertion rod inside is along the length direction and is opened the sliding slot, the sliding slot front end is closed and has the strip hole on the upper surface, lock tongue slidingly fits in the sliding slot, the top surface of lock tongue is the wedge inclined plane, the sliding slot tail end is equipped with the screw hole, adjusting bolt is spun into the screw hole, compression spring is placed in the sliding slot, and two ends are pressed respectively the end of adjusting bolt and the back end surface of lock tongue, the utility model discloses can overcome the problem of traditional steel wire rope jam difficult to dismantle, and the construction efficiency is improved greatly, and the construction cost is reduced.

Description

Technical Field

[0001] This utility model relates to a lifting device. More specifically, this utility model relates to a lifting tool for prefabricated grid beams. Background Technology

[0002] Precast grid beams typically have a large volume and heavy weight, posing numerous technical challenges during handling and hoisting on slopes.

[0003] The conventional hoisting method used in current projects involves binding steel wire ropes through pre-set hoisting holes on all four sides of the precast grid beam. However, after hoisting, the pressure exerted by the beam's own weight on the steel wire ropes causes them to become tightly interlocked with the inner wall of the hoisting holes, requiring multiple workers to disassemble. This is not only labor-intensive but also time-consuming, severely impacting the construction schedule. To meet the space requirements for disassembling the steel wire ropes, the already pre-leveled installation slope needs to be leveled again, adding extra earthwork. Furthermore, uneven stress during the binding process can easily cause damage to the concrete at the corners of the grid beam, directly affecting the appearance and structural performance of the components.

[0004] Therefore, it is necessary to design a technical solution that can overcome the above-mentioned defects. Utility Model Content

[0005] One objective of this invention is to provide a precast grid beam hoisting tool that can overcome the problem of traditional wire rope jamming and difficulty in dismantling, thereby significantly improving construction efficiency and reducing construction costs.

[0006] To achieve these objectives and other advantages of this utility model, according to one aspect of this utility model, a precast grid beam hoisting tool is provided, comprising a hoisting body, a locking tongue, a compression spring, and an adjusting bolt; the hoisting body has a vertical connecting rod and a horizontal inserting rod, the top end of the connecting rod is provided with a crane connecting ring, the inserting rod is used to insert into the hoisting hole of the precast grid beam, the inserting rod has a groove along its length, the front end of the groove is closed and the upper surface has a strip-shaped hole; the locking tongue is slidably fitted into the groove, the top surface of the locking tongue is a wedge-shaped inclined surface, the end of the groove is provided with a threaded hole, the adjusting bolt is screwed into the threaded hole, the compression spring is placed inside the groove, and its two ends respectively abut against the end of the adjusting bolt and the rear end face of the locking tongue.

[0007] Furthermore, the front end of the insertion rod is provided with a through pin hole, and the pin hole is used to assemble a pin; the middle section of the pin is provided with an annular limiting groove, and the side wall of the pin hole is provided with a radial threaded hole. By screwing a limiting screw into the radial threaded hole, the end of the limiting screw is embedded in the annular limiting groove, thereby realizing the connection between the pin and the insertion rod.

[0008] Furthermore, guide blocks are protruding from the left and right sides of the latch; guide grooves adapted to the guide blocks are opened on the left and right inner sidewalls of the slide groove, and the guide blocks are slidably embedded in the guide grooves; a guide post is coaxially fixedly connected to the end of the adjusting bolt that extends into the slide groove; the compression spring is sleeved on the guide post, with one end pressing against the end of the adjusting bolt and the other end pressing against the rear end face of the latch.

[0009] Furthermore, the adjusting bolt is provided with an operating handle or knob at the end located outside the main body of the lifting device for easy manual rotation.

[0010] Furthermore, a lock nut is screwed onto the adjusting bolt.

[0011] Furthermore, the angle between the wedge-shaped inclined surface of the top surface of the latch and the horizontal plane is 30° to 60°.

[0012] Furthermore, the top surface of the latch has a horizontal holding surface behind the wedge-shaped ramp.

[0013] This utility model has at least the following beneficial effects:

[0014] This invention utilizes an insertion rod embedded in the lifting hole of a precast grid beam. The locking tongue automatically pops out through the strip hole under the action of a compression spring. Its wedge-shaped inclined surface forms a mechanical self-lock with the inner wall of the lifting hole and can adapt to lifting holes of different sizes. During disassembly, only the adjusting bolt needs to be rotated to release the spring pressure, and the locking tongue can retract into the slide groove. A single person can complete the tool disassembly, solving the problem of traditional wire rope jamming and difficulty in disassembly, greatly improving construction efficiency and reducing construction costs.

[0015] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the slide groove of this utility model;

[0017] Figure 2 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0019] It should be understood that terms such as "having," "comprising," and "including" used in the embodiments of this application do not exclude the presence or addition of one or more other elements or combinations thereof. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. When an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or may have an intervening element present. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element through an intervening element. Descriptions involving "first," "second," etc., in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0020] It should be noted that the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0021] like Figure 1 , 2 As shown, the embodiments of this application provide a precast grid beam hoisting tool including a hoisting body, a locking tongue 3, a compression spring 4, and an adjusting bolt 5; the hoisting body has a vertical connecting rod 1 and a horizontal inserting rod 2, the top of the connecting rod 1 is provided with a crane connecting ring 101, the inserting rod 2 is used to insert into the hoisting hole of the precast grid beam, the inserting rod 2 has a sliding groove 201 opened along the length direction inside, the front end of the sliding groove 201 is closed and the upper surface has a strip-shaped hole; the locking tongue 3 is slidably fitted into the sliding groove 201, the top surface of the locking tongue 3 is a wedge-shaped inclined surface, the end of the sliding groove 201 is provided with a threaded hole, the adjusting bolt 5 is screwed into the threaded hole, the compression spring 4 is placed inside the sliding groove 201, and the two ends respectively press against the end of the adjusting bolt 5 and the rear end face of the locking tongue 3.

[0022] For example, the main body of the lifting device is integrally forged from Q345B steel. The connecting rod 1 is cylindrical and is vertically welded to the center of the top surface of the insertion rod 2. The top end is formed by an annular forging to form a crane connecting ring 101. The connecting ring 101 is a closed ring with an inner diameter that matches the crane hook. The insertion rod 2 is a flat cuboid with a front end slightly narrower than the rear end to facilitate alignment with the insertion hole. A through rectangular groove 201 is machined along its length inside. The front end of the groove 201 is closed by the front end face of the insertion rod 2, forming a limiting surface for the forward movement of the locking tongue 3. A strip-shaped hole is opened on the upper surface of the groove 201. The length direction of the strip-shaped hole is consistent with the axis of the insertion rod 2, and the width is 2 mm larger than the thickness of the locking tongue 3 to ensure that the wedge-shaped inclined surface on the top surface of the locking tongue 3 can extend smoothly. The locking tongue 3 is a rectangular block structure. Its bottom surface fits into the bottom surface of the slide groove 201, and its left and right sides have a 1 mm gap from the inner wall of the slide groove 201. The top surface is machined into a wedge-shaped bevel with an angle of 45° between the bevel and the bottom surface. The end of the bevel extends to the front end of the locking tongue 3, and the front end face is parallel to the front end face of the insertion rod 2. The threaded hole at the end of the slide groove 201 is a blind hole with a diameter matching the outer diameter of the thread of the adjusting bolt 5. The tail of the adjusting bolt 5 is a hexagonal prism for easy rotation with a wrench. Its front end has a cylindrical part with a diameter smaller than that of the threaded section. The compression spring 4 is sleeved on the cylindrical part, with one end abutting against the stepped surface of the adjusting bolt 5 and the other end abutting against the circular groove on the rear end face of the locking tongue 3. The depth of the groove is adapted to the free length of the spring.

[0023] In this embodiment, during operation, the insertion rod 2 is horizontally inserted into the lifting hole of the precast grid beam. The locking tongue 3 slides forward under the thrust of the compression spring 4, and the wedge-shaped inclined surface extends from the strip hole and contacts the inner wall of the upper edge of the lifting hole. When the crane lifts the connecting rod 1, the weight of the beam presses against the wedge-shaped inclined surface through the inner wall of the lifting hole. The inclined surface decomposes the vertical pressure into a horizontal component and a vertical component. The horizontal component pushes the locking tongue 3 backward to compress the spring 4, while the reaction force of the spring makes the locking tongue 3 press tightly against the inner wall of the lifting hole, forming a self-locking effect of the inclined surface. During disassembly, the adjusting bolt 5 is rotated counterclockwise with a wrench. The adjusting bolt 5 is pulled back, the spring compression decreases, and the locking tongue 3 retracts into the groove 201 under the pressure of the inner wall of the lifting hole. At this time, the insertion rod 2 has no contact force with the lifting hole and can be easily pulled out. This structure achieves automatic locking during hoisting and convenient release during disassembly through the combination of wedge-shaped inclined surfaces and spring force, avoiding the problem of traditional wire ropes being difficult to disassemble due to compression and jamming. Furthermore, the point contact between the locking tongue 3 and the lifting hole is transformed into inclined surface contact, which disperses local stress and reduces component damage.

[0024] In another embodiment, the front end of the insertion rod 2 is provided with a through pin hole, and the pin hole is used to assemble the pin 6; the middle section of the pin 6 is provided with an annular limiting groove, and the side wall of the pin hole is provided with a radial threaded hole. By screwing a limiting screw 7 into the radial threaded hole, the end of the limiting screw 7 is embedded in the annular limiting groove, thereby realizing the connection between the pin 6 and the insertion rod 2.

[0025] For example, the pin hole at the front end of the insertion rod 2 is a circular through hole with its axis perpendicular to the length direction of the insertion rod 2. The hole diameter is 25 mm, and the hole depth extends through the width direction of the insertion rod 2. The pin 6 is a cylindrical rod made of 40Cr material with a quenched and tempered surface. An annular limiting groove is machined in the middle section, with a groove depth of 4 mm and a groove width of 10 mm. The circumferential direction of the groove is concentric with the axis of the pin 6. A radial threaded hole is machined in the middle of the side wall of the pin hole. The axis of the threaded hole intersects the axis of the pin hole perpendicularly. The hole diameter is M12, and the hole depth is 20 mm. The limiting screw 7 is a hexagonal head screw with a hemispherical end. After being screwed into the radial threaded hole, the hemispherical end is embedded in the annular limiting groove to form a circumferential limit. Both ends of the pin 6 extend 15 mm beyond the front end face of the insertion rod 2 for installing auxiliary positioning sleeves or bearing lateral shear forces.

[0026] In this embodiment, during assembly, the pin 6 is first passed through the pin hole, aligning the annular limiting groove with the radial threaded hole. Then, the limiting screw 7 is screwed into the threaded hole until the screw end is completely embedded in the groove. At this point, the pin 6 is restricted within the pin hole and cannot move axially. During hoisting, if the front end of the insertion rod 2 is subjected to lateral force, the pin 6 acts as a fulcrum. Through the cooperation of the limiting screw 7 and the annular groove, the axial force is converted into compressive stress between the screw end and the groove wall, preventing the pin 6 from falling off. This structure uses radial limiting to fix the pin 6. Compared to traditional cotter pin or snap ring connections, the preload of the limiting screw 7 can be controlled by a torque wrench, making the connection more reliable. It is especially suitable for frequent hoisting operations in vibrating environments, ensuring the stability of the front end structure of the insertion rod 2 and preventing hoisting safety hazards caused by the loosening of the pin 6.

[0027] In another embodiment, guide blocks are protruding on the left and right sides of the latch 3; guide grooves adapted to the guide blocks are opened on the left and right inner sidewalls of the slide groove 201, and the guide blocks are slidably embedded in the guide grooves; a guide post is coaxially fixedly connected to the end of the adjusting bolt 5 that extends into the slide groove 201; a compression spring 4 is sleeved on the guide post, one end of which presses against the end of the adjusting bolt 5, and the other end presses against the rear end face of the latch 3.

[0028] For example, a rectangular guide block is welded to the middle of each of the left and right sides of the latch 3. The guide block is 50 mm long, 15 mm wide, and 10 mm high, and its material is the same as that of the latch 3. Rectangular guide grooves are machined at corresponding positions on the left and right inner sidewalls of the slide 201. The grooves are 12 mm deep, 16 mm wide, and the length is the same as that of the slide 201. After the guide block is embedded in the guide groove, there is a 0.5 mm gap on both sides to ensure smooth sliding without obvious shaking. The end of the adjusting bolt 5 that extends into the slide 201 is fixed with a cylindrical guide post by threaded connection or welding. The guide post has a diameter of 20 mm, a length of 30 mm, and its axis coincides with the axis of the adjusting bolt 5. The compression spring 4 is a cylindrical helical spring with an inner diameter of 22 mm, an outer diameter of 30 mm, and a free length of 80 mm. It is fitted on the guide post, with one end abutting against the circular boss at the end of the adjusting bolt 5. The boss has a diameter of 25 mm, and the other end abutting against the recess on the rear end face of the latch 3. The diameter of the recess matches the outer diameter of the spring, and the depth is 5 mm.

[0029] In this embodiment, when the latch 3 slides back and forth within the slide groove 201, the guide block moves synchronously along the guide groove. The groove wall restricts the lateral displacement of the latch 3, ensuring that the wedge-shaped inclined surface of the latch 3 is always aligned with the strip hole, avoiding jamming due to misalignment. The guide post provides axial guidance for the compression spring 4, preventing the spring from bending or becoming eccentric during compression, and ensuring that the spring force is evenly applied to the center position of the rear end face of the latch 3. When the adjusting bolt 5 rotates, the guide post moves with the bolt, pushing the latch 3 to translate through the spring. The cooperation between the guide block and the guide groove reduces sliding friction, making the movement of the latch 3 smoother. This structure, through the mechanical guiding mechanism and spring limiting design, improves the accuracy and reliability of the latch 3's movement. Even under long-term, high-frequency use, it can maintain good sliding performance, reduce component wear, extend the service life of the lifting equipment, and ensure the stable and reliable self-locking function of the latch 3 during lifting.

[0030] In another embodiment, the adjusting bolt 5 is provided with an operating handle or knob at the end located outside the main body of the lifting device for easy manual rotation.

[0031] For example, the tail of the adjusting bolt 5 extends 20 mm beyond the rear end face of the insertion rod 2. This end is machined into a square prism or a knurled cylindrical structure for mounting an operating handle or knob. The operating handle can be an L-shaped steel rod with a square hole or an internal hexagonal hole at one end, adapted to the tail of the adjusting bolt 5, and fixed by an interference fit or a set screw; it can also be a disc-shaped knob, with the center hole of the knob connected to the tail of the adjusting bolt 5 by a key or threaded connection, and the outer circumference of the knob machined with anti-slip teeth or knurling. The length of the operating handle can be 150 mm for easy gripping and force application by the operator, and the diameter of the knob can be 80 mm to provide sufficient rotational torque.

[0032] In this embodiment, when it is necessary to adjust the position of the locking tongue 3 or the compression of the spring, the construction worker does not need to use additional tools. They can simply hold the operating handle or knob and rotate it clockwise or counterclockwise to rotate the adjusting bolt 5, thus enabling the locking tongue 3 to move forward or backward. Compared to the traditional method of using a wrench to rotate the bolt, this structure simplifies the operation and saves time. Especially in high-altitude operations or confined spaces, the operator can complete the adjustment with one hand, improving construction convenience and safety.

[0033] In another embodiment, a locking nut is screwed onto the adjusting bolt 5.

[0034] For example, a hexagonal lock nut is screwed onto the threaded section of the adjusting bolt 5 on the outside of the insertion rod 2. The nut's specifications match those of the adjusting bolt 5, and its material is Q235 steel or 35# steel. A flange face is provided on one side of the nut, with a flange face diameter 5 mm larger than the outer diameter of the nut, to increase the contact area with the rear end face of the insertion rod 2. After the adjusting bolt 5 is adjusted into place, the lock nut is tightened with a wrench, causing its flange face to press firmly against the rear end face of the insertion rod 2, generating a frictional torque to prevent the adjusting bolt 5 from loosening due to vibration or external force.

[0035] In this embodiment, after the spring preload is set by rotating the adjusting bolt 5, the locking nut is tightened. The friction between the nut and the end face of the insertion rod 2, along with the self-locking characteristic of the threaded pair, locks the adjusting bolt 5 in its current position. During hoisting, even if the lifting device is subjected to vibration or impact loads, the locking nut prevents the adjusting bolt 5 from loosening, ensuring the spring preload remains stable and thus guaranteeing the reliable self-locking performance of the locking tongue 3. Compared to a structure without a locking nut, this design improves the stability and safety of the lifting device during long-term use and reduces the risk of locking failure due to bolt loosening.

[0036] In another embodiment, the wedge-shaped inclined surface of the top surface of the latch 3 forms an angle of 30° to 60° with the horizontal plane.

[0037] For example, the wedge-shaped slope on the top surface of the locking tongue 3 can be selected at an angle of 30°, 45°, or 60°. When the angle is 30°, the slope is relatively gentle, and the horizontal component force generated by the locking tongue 3 under vertical pressure is small, requiring a larger spring preload to achieve reliable self-locking. However, the torque required to rotate the adjusting bolt 5 during disassembly is also smaller. When the angle is 45°, the horizontal and vertical components are equal, and the spring preload and disassembly torque are relatively balanced, making it a commonly used angle selection. When the angle is 60°, the slope is steep, the horizontal component force is large, and a smaller spring preload is sufficient to achieve self-locking, but a larger torque is required to overcome friction during disassembly. In practical applications, a suitable angle can be selected based on the weight of the precast grid beam, the size of the lifting holes, and the material properties.

[0038] In this embodiment, the angle of the wedge-shaped ramp determines the self-locking performance and ease of disassembly of the locking tongue 3. When the lifting device is under load, the wedge-shaped ramp contacts the inner wall of the lifting hole. The load is decomposed into horizontal and vertical components through the ramp. The horizontal component compresses the spring 4, and the vertical component provides friction to achieve self-locking. The smaller the angle, the stronger the self-locking ability, but the more difficult the adjustment; the larger the angle, the easier the adjustment, but the lower the self-locking reliability. By controlling the angle within the range of 30° to 60°, the self-locking reliability can be guaranteed while the ease of adjustment can be taken into account, making the lifting device suitable for lifting operations under different working conditions. Compared with a single-angle design, it has a wider range of applicability and flexibility.

[0039] In another embodiment, the top surface of the latch 3 has a horizontal holding surface behind the wedge-shaped ramp.

[0040] For example, the wedge-shaped bevel on the top surface of the latch 3 extends rearward from the front end of the latch 3, and a horizontal supporting surface is connected to the rear end of the bevel. The length of the supporting surface can be 1 / 3 of the length of the latch 3, and the width is the same as the width of the latch 3. A rounded transition is used between the supporting surface and the wedge-shaped bevel, with a transition radius of 5 mm, to avoid stress concentration. The surface roughness Ra of the supporting surface can be 3.2 μm to ensure good contact with the inner wall of the lifting hole.

[0041] In this embodiment, when the locking tongue 3 extends under the action of the spring and contacts the inner wall of the lifting hole, the wedge-shaped inclined surface first contacts the inner wall and generates a self-locking force. As the load increases, the horizontal supporting surface gradually comes into contact with the inner wall of the lifting hole, sharing part of the load, transforming point contact into surface contact, reducing local pressure, and preventing damage to the inner wall of the lifting hole due to stress concentration. At the same time, the presence of the supporting surface increases the contact area between the locking tongue 3 and the inner wall of the lifting hole, improving friction and self-locking stability, enabling the lifting device to withstand greater loads. Compared with a structure that relies solely on the wedge-shaped inclined surface for locking, this design extends the service life of the lifting device and prefabricated components, and improves the safety and reliability during the lifting process.

[0042] The number of devices and processing capacity described herein are for simplification. Applications, modifications, and variations of the precast grid beam hoisting tool of this invention will be readily apparent to those skilled in the art.

[0043] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A hoisting tool for precast grid beams, characterized in that, Includes the main body of the lifting device, locking tongue, compression spring, and adjusting bolts; The lifting device has a vertical connecting rod and a horizontal inserting rod. The top of the connecting rod is provided with a crane connecting ring. The inserting rod is used to insert into the lifting hole of the precast grid beam. The inserting rod has a sliding groove along its length inside. The front end of the sliding groove is closed and the upper surface has a strip hole. The latch slides into the groove, the top surface of the latch is a wedge-shaped slope, the end of the groove is provided with a threaded hole, the adjusting bolt is screwed into the threaded hole, the compression spring is placed inside the groove, and its two ends respectively press against the end of the adjusting bolt and the rear end face of the latch.

2. The precast grid beam hoisting tool as described in claim 1, characterized in that, The front end of the insertion rod has a through pin hole, and the pin hole is used to assemble a pin. The middle section of the pin is provided with an annular limiting groove, and the side wall of the pin hole is provided with a radial threaded hole. By screwing a limiting screw into the radial threaded hole, the end of the limiting screw is embedded in the annular limiting groove, thereby realizing the connection between the pin and the insertion rod.

3. The precast grid beam hoisting tool as described in claim 1, characterized in that, Guide blocks are protruding on the left and right sides of the latch; The left and right inner sidewalls of the slide groove are provided with guide grooves that are adapted to the guide block, and the guide block is slidably embedded in the guide groove; The end of the adjusting bolt that extends into the slide groove is coaxially fixedly connected to a guide post. The compression spring is sleeved on the guide post, with one end pressing against the end of the adjusting bolt and the other end pressing against the rear end face of the locking tongue.

4. The precast grid beam hoisting tool as described in claim 1, characterized in that, The adjusting bolt is located at the end of the lifting device body outside and is equipped with an operating handle or knob for easy manual rotation.

5. The precast grid beam hoisting tool as described in claim 1 or 2, characterized in that, A lock nut is screwed onto the adjusting bolt.

6. The precast grid beam hoisting tool as described in claim 1, characterized in that, The angle between the wedge-shaped inclined surface of the top surface of the latch and the horizontal plane is 30° to 60°.

7. The precast grid beam hoisting tool as described in claim 1, characterized in that, The top surface of the latch has a horizontal bearing surface behind the wedge-shaped ramp.

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