Height-adjustable steel ladder

Abstract

The invention relates to the technical field of steel ladders, in particular to a height-adjustable steel ladder which comprises a ladder body assembly, a supporting and adjusting assembly and an anti-falling mechanism, the upper end of the ladder body assembly is hinged to a grain checking platform, the ladder body assembly can rotate around a hinge point by 0-90 degrees, a double / middle supporting mode is arranged, step plate hinging guarantees levelness, and a protective handrail and a climbing rod are arranged to improve safety; the supporting and adjusting assembly comprises an arc-shaped rail groove, a sliding block and a length-adjustable supporting piece, rails can be calibrated to the same vertical plane, the adjusting mechanism is provided with a cable body driving mode and a gear transmission mode, and flexible adjustment of the angle of the ladder body is achieved. The anti-falling mechanism is composed of a safety anti-falling cable and a finished anti-falling device, and the ladder body can be locked instantly when the adjusting mechanism fails. The angle of the steel ladder can be adaptively adjusted according to the grain loading height, and the steel ladder is smooth in operation, convenient to operate, flexible and space-saving in storage, reliable in safety protection, high in universality and suitable for being popularized and used in various grain depots and warehouses with height adjusting requirements.

Description

Technical Field

[0001] This invention relates to the field of steel ladder technology, and specifically to an adjustable height steel ladder. Background Technology

[0002] Currently, during the design phase of grain depots, the height of the grain loading line on the grain inspection platform is calculated based on the grain bulk density specified in the regulations. However, in actual grain depot operations, due to the influence of different grain types in different regions and the storage characteristics of grain at different times, there is a significant difference between the actual grain bulk density and the design value. Furthermore, there are strict upper limits on the total storage capacity of grain depots. As a result, the actual grain loading height of high-rise grain depots such as shallow circular silos, multi-story silos, and vertical silos is generally lower than the designed grain loading height, resulting in a height difference of 0 to 2 meters. The higher the designed grain loading height and the greater the actual grain bulk density, the more significant this height difference becomes.

[0003] The existing steel ladders for grain inspection in grain depots are fixed structures, with their installation height set according to the designed grain loading line height. This fails to adapt to variations in actual grain loading height, resulting in defects in the connection between the inspection platform and the actual grain loading surface. Furthermore, the fixed steel ladders lack flexible adjustment capabilities. If a shorter ladder is designed to accommodate higher designed loading heights, the ladder cannot directly reach the loading surface when the actual loading height is lower. Conversely, if a shorter ladder is designed to accommodate lower loading heights, the ladder may end up buried in the grain pile, causing grain contamination. Summary of the Invention

[0004] In view of the aforementioned defects and problems of existing steel ladders for grain inspection in grain depots, such as poor adaptability and inconvenience of use, this invention provides an adjustable height steel ladder that is suitable for grain inspection operations in grain depots, solving the problem that existing fixed steel ladders cannot adapt to changes in the actual grain loading height in grain depots.

[0005] The solution adopted by this invention to solve its technical problem is: an adjustable height steel ladder, including a ladder body assembly, a support adjustment assembly, and a safety protection assembly; the upper end of the ladder body assembly is hinged to a grain inspection platform, and the lower end is slidably connected to the support adjustment assembly; the ladder body assembly can rotate around the hinge point within a range of 0° to 90° to adapt to different grain loading heights; the support adjustment assembly includes a track structure fixed to the wall and an adjustment mechanism for driving the ladder body assembly to rotate; the track structure is connected to a wall-embedded part through an adjustable-length support member, which is used to calibrate the track structure to the same vertical plane; the safety protection assembly includes a fall protection mechanism, which is connected to the lower end of the ladder body assembly and is used to lock the position of the ladder body assembly to prevent it from falling when the adjustment mechanism fails.

[0006] Furthermore, the ladder assembly includes a main ladder beam, a supporting ladder beam, a lower supporting beam, and treads. The main ladder beams are symmetrically arranged on both sides of the treads, and the treads are arranged at equal intervals along the length of the main ladder beams. The two ends of the treads are hinged to the main ladder beams. The supporting ladder beams are located at the lower middle or both ends of the treads. The lower end of the ladder assembly is fixed with a lower supporting beam perpendicular to the main ladder beam. The main ladder beams are equipped with guardrails, and the ends of the treads are equipped with climbing bars.

[0007] Furthermore, the support adjustment assembly includes a track groove, a track sliding block, and a support member. The track groove is an arc-shaped structure and is installed in a pre-embedded part in the wall through the support member. The track sliding block is rotatably mounted on the end of the lower support beam of the ladder assembly, and the track sliding block is locked in the track groove and slides relative to the track groove.

[0008] Furthermore, the support includes a base sleeve, an adjusting screw, and two locking nuts. The base sleeve is fixed to the wall-embedded part. One end of the adjusting screw is connected to the track groove through a fisheye bearing and has a rotating end. The other end of the adjusting screw is threadedly connected to the base sleeve. The locking nuts are threadedly fitted onto the adjusting screw. When the adjusting screw is adjusted to the correct position, the locking nuts press against the base sleeve to achieve axial limiting of the adjusting bolt.

[0009] Furthermore, the adjustment mechanism includes an angle adjustment cable, a pulley, and a drive component. One end of the angle adjustment cable is connected to the lower support beam of the ladder assembly, and the other end passes through the pulley on the roof and is connected to the drive component. The drive component is a manual winch or an electric winch.

[0010] Furthermore, the fall protection mechanism includes a safety fall arrestor and a prefabricated fall arrestor. The prefabricated fall arrestor is fixed to the roof or floor. One end of the safety fall arrestor is connected to the lower end of the ladder assembly, and the other end is connected to the prefabricated fall arrestor. The safety fall arrestor adapts to the rotation of the ladder assembly.

[0011] The beneficial effects of this invention are: The upper end of the steel ladder assembly of this invention is hinged to the grain inspection platform and can rotate freely around the hinge point. The inclination angle of the steel ladder can be flexibly adjusted according to the actual grain loading height of the grain depot: when the grain loading height is high, the angle of the steel ladder is reduced to make the ladder slope gentler and improve the convenience of personnel going up and down; when the grain loading height is low, the angle of the steel ladder is increased to make the ladder slope steeper and reduce space occupation. This effectively solves the problem that existing fixed steel ladders cannot adapt to the design and actual grain loading height difference. When the steel ladder of this invention is not in use, it can also be adjusted to rotate to a horizontal or vertical state for storage. Compared with traditional fixed steel ladders, this greatly reduces the space occupation inside the grain depot, avoids interference with grain loading, unloading, storage and other operations in the grain depot, and improves the utilization rate of grain depot space. This invention designs two types of ladder structure: double support and central support. The choice can be made flexibly according to the space conditions and load-bearing requirements of the grain depot. The main ladder beam, the supporting ladder beam, and the lower supporting beam form a stable load-bearing frame. The two ends of the step plate are hinged to the main ladder beam, so that it always remains horizontal as the ladder angle changes, ensuring the stability of personnel walking. The track groove in the support adjustment assembly is connected to the wall embedded parts through adjustable support components. The support components consist of a base sleeve, an adjusting screw, and a locking nut. The extension length can be changed by rotating the adjusting screw, and the fish-eye bearing is used to adapt to the installation angle deviation. Multiple sets of support components arranged along the track groove can be adjusted one by one, effectively compensating for the flatness deviation of the grain depot wall, ensuring that the entire track groove is in the same vertical plane, and ensuring that the ladder slides smoothly along the track groove during the adjustment process without jamming or sticking. Attached Figure Description

[0012] Figure 1 This is an additional steel ladder plan view of the present invention; Figure 2 This is a cross-sectional view of the double-supported additional steel ladder of the present invention; Figure 3 This is a side view of the additional steel ladder in a horizontal position according to the present invention; Figure 4 This is a side view of the additional steel ladder in its vertical state according to the present invention; Figure 5 This is a side view of the additional steel ladder in an inclined state according to the present invention; Figure 6 This is a cross-sectional view of the single-support additional steel ladder of the present invention; Figure 7 This is a cross-sectional view of the support member of the present invention.

[0013] In the diagram: 1. Main ladder beam; 2. Supporting ladder beam; 3. Steps; 4. Climbing pole; 5. Guardrail; 6. Lower support beam; 7. Track groove; 8. Track sliding block; 9. Angle adjustment cable; 10. Safety fall arrestor cable; 11. Pulley; 12. Finished fall arrestor; 13. Base sleeve; 14. Adjusting screw; 15. Fish eye bearing; 16. Rotating end; 17. Locking nut. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Please see Figure 1-7 This invention provides a technical solution for an adjustable height steel ladder: Example

[0016] An adjustable-height steel ladder mainly consists of a ladder body assembly and a support and adjustment assembly. For example... Figure 1 and Figure 3As shown, the ladder assembly, serving as the core load-bearing structure for warehouse management personnel, mainly consists of a main ladder beam 1, supporting ladder beams 2, a lower supporting beam 6, and step plates 3. The main ladder beams 1 are symmetrically arranged on both sides of the step plates 3, and are made of rigid materials such as channel steel, square steel pipes, or steel plates. Their upper ends are hinged to the grain inspection platform for rotational connection. Wear-resistant bearings are used at the hinge points as rotating pairs to ensure smooth, uninterrupted ladder rotation while maintaining sufficient connection strength to meet load-bearing requirements. The step plates 3 are evenly spaced along the length of the main ladder beams 1, and their ends are hinged to the main ladder beams 1. This connection method ensures that the step plates 3 remain horizontal when the ladder angle changes, guaranteeing stability for personnel walking. The supporting ladder beams 2 are arranged in two ways: as shown... Figure 2 As shown, in the double-support configuration, the two supporting ladder beams 2 are respectively located at both ends below the step plate 3, arranged parallel to the main ladder beam 1, together forming a stable load-bearing frame; as Figure 6 As shown, in the middle support configuration, a single support beam 2 is positioned in the middle below the step plate 3. By providing bottom support to the middle of the step plate 3, the force is evenly distributed. The two support configurations can be flexibly selected according to the space conditions and load-bearing requirements of the grain depot. The lower support beam 6 is vertically fixed to the lower end of the main ladder beam 1. It is made of materials such as channel steel, I-beam steel, or square steel, and its length is designed according to the overall width of the ladder. It is used to connect the track sliding block 8 and transmit the force of the ladder. A guardrail 5 is also fixedly installed on the main ladder beam 1. The guardrail 5 is continuously arranged along the length of the main ladder beam 1, and its height meets the safety operation standards, effectively preventing personnel from falling from both sides of the ladder. Climbing rods 4 are fixedly installed at the ends of the step plates 3. The climbing rods 4 are arranged perpendicular to the step plates 3. When the ladder is at a large angle or in a vertical state, they provide additional gripping support for personnel going up and down, improving the safety of operation.

[0017] The support and adjustment assembly is used to achieve sliding support and track alignment of the ladder, including track groove 7, track sliding block 8, and support components. For example... Figure 3-5 As shown, the track groove 7 has an arc-shaped structure, and its curvature design is adapted to the rotation trajectory of the ladder, ensuring that the track sliding block 8 can always slide smoothly along the track groove 7 when the ladder rotates within the range of 0° to 90°. The track groove 7 is made of steel plate by bending, and the inner side of the groove is treated with wear-resistant material to reduce friction loss between it and the track sliding block 8 and extend its service life. The track sliding block 8 is rotatably fitted onto the end of the lower support beam 6, and its shape is adapted to the groove of the track groove 7, so that it can be locked in the track groove 7 and slide relative to it. At the same time, the rotatable connection eliminates the lateral force generated when the ladder rotates and avoids jamming. The support member serves as the connection structure between the track groove 7 and the wall embedded part, and is used to adjust the installation position of the track groove 7 to ensure that it is in the same vertical plane, such as... Figure 7As shown, the support consists of a base sleeve 13, an adjusting screw 14, and two locking nuts 17. The base sleeve 13 is fixedly connected to a pre-embedded part in the wall, which is pre-installed in the grain depot wall to ensure connection strength and stability. One end of the adjusting screw 14 is connected to the track groove 7 via a fisheye bearing 15, which allows for a certain angle of deflection to accommodate the installation angle deviation of the track groove 7. The other end of the adjusting screw 14 is connected to the base sleeve 13 via a threaded connection. The outer end of the adjusting screw 14 is provided with a rotating end 16, which allows the adjusting screw 14 to be rotated with a tool to change its extension length. The two locking nuts 17 are threaded onto the adjusting screw 14. After the position of the track groove 7 is calibrated, the locking nuts 17 are tightened to make it press against the base sleeve 13, thereby achieving axial limit of the adjusting screw 14 and preventing positional displacement due to vibration during use. At least three sets of support members are arranged along the length of the track groove 7. By adjusting the length of each support member in turn, the flatness deviation of the grain depot wall can be effectively compensated, ensuring that the track groove 7 is in the same vertical plane, thus guaranteeing the smooth sliding of the track sliding block 8.

[0018] The adjustment mechanism employs a cable-driven system, consisting of an angle adjustment cable 9, a pulley 11, and a drive component. It drives the ladder assembly to rotate around the hinge point. The angle adjustment cable 9 is made of high-strength, high-toughness materials such as steel strand. One end is fixedly connected to the lower support beam 6 to ensure balanced force distribution; the other end passes through the pulley 11 installed on the roof and connects to the drive component. The pulley 11 is fixed to the roof steel structure by a bracket. Its installation position is designed according to the ladder's rotation trajectory to ensure that the force direction of the angle adjustment cable 9 is consistent with the ladder's rotation direction, reducing friction. The drive component can be a manual or electric winch, installed in an easily accessible location on the grain inspection platform. When the ladder angle needs to be reduced to accommodate a higher grain loading height, the angle adjustment cable 9 is tensioned by the drive component. The angle adjustment cable 9 shortens and pulls the lower support beam 6, causing the ladder to rotate around the upper hinge point, and the angle gradually decreases. When the ladder angle needs to be increased to accommodate a lower grain loading height, the angle adjustment cable 9 is released by the drive component. The ladder falls under its own weight, and the angle gradually increases until the desired position is reached. Then, the length of the angle adjustment cable 9 is fixed by the self-locking function of the drive component, thus locking the ladder angle.

[0019] In practical use, the working process of this adjustable height steel ladder is as follows: Based on the actual grain loading height of the grain depot and the height difference between the grain inspection platform and the actual loading height, the required tilt angle of the ladder is determined. If the loading height is high, the angle adjustment cable is tensioned by operating the drive mechanism (manual or electric winch) on the grain inspection platform. The angle adjustment cable changes the direction of force through pulleys, pulling the lower support beam and causing the track sliding block to slide along the arc-shaped track groove, causing the ladder to rotate around the upper hinge point, gradually decreasing the angle until the lower end of the ladder matches the loading height. If the loading height is low, the angle adjustment cable is released by operating the drive mechanism, and the ladder falls naturally under its own weight. The track sliding block slides in the opposite direction along the track groove, gradually increasing the ladder angle. After reaching the target angle, the length of the angle adjustment cable is fixed using the self-locking function of the drive mechanism, completing the angle locking. Personnel ascend and descend the grain inspection platform via the steps. The guardrails prevent personnel from falling sideways. When the ladder angle is large or in a near-vertical state, personnel can hold onto the climbing bars at the ends of the steps to maintain balance, improving operational safety. When the grain storage height changes, repeat the above angle adjustment operation to adapt to the new height difference requirements. When not in use, the ladder can be adjusted to a horizontal state (0°) for storage to reduce space occupation, or adjusted to a vertical state (90°) to fit against the wall to avoid affecting other operations in the grain storage. Example

[0020] Based on Embodiment 1, the similarities between this embodiment and Embodiment 1 will not be repeated. The differences are as follows: a fall arrest mechanism is added. The fall arrest mechanism consists of a safety fall arrest cable 10 and a prefabricated fall arrestor 12, and is independent of the adjustment mechanism. The safety fall arrest cable 10 is made of high-strength steel strand, and its strength can meet the load-bearing requirements of the ladder assembly. One end of the safety fall arrest cable 10 is fixedly connected to the lower support beam 6 of the ladder assembly, and the connection point is staggered from the connection point of the angle adjustment cable 9 to avoid mutual interference; the other end is connected to the prefabricated fall arrestor 12 fixed on the roof or floor. The prefabricated fall arrestor 12 is a mature product with instantaneous locking function, which allows the safety fall arrest cable 10 to extend and retract freely to adapt to the angle adjustment of the ladder assembly. During normal adjustment, the safety fall arrest cable 10 naturally extends and retracts with the rotation of the ladder, without affecting the adjustment operation and without being subjected to force itself. When the adjustment mechanism fails, such as the angle adjustment cable 9 breaking or the drive component's self-locking failing, and the ladder assembly shows a rapid downward trend, the prefabricated fall arrestor 12 can trigger the locking mechanism in a very short time, locking the safety fall arrestor cable 10 and preventing the ladder assembly from continuing to fall, thereby ensuring the safety of personnel on the ladder. The selection of the prefabricated fall arrestor 12 must consider the telescopic length of the safety fall arrestor cable 10, ensuring it can cover the maximum telescopic range of the safety fall arrestor cable 10 during the ladder assembly's rotation from 0° to 90°. Simultaneously, its locking load must match the maximum load-bearing weight of the ladder assembly to ensure reliable locking performance. Example

[0021] The adjustment mechanism in Embodiment 1 can also be replaced by a gear transmission mechanism. A rack is fixedly installed inside the track groove 7, arranged along the arc-shaped trajectory of the track groove 7. The motor is fixedly installed on the track sliding block 8, and its output end is fixedly connected to the gear. The gear and rack mesh with each other, forming a gear transmission pair. A model with speed regulation is selected for the motor. By controlling the forward and reverse rotation and the speed of the motor, the gear can be driven to move along the rack, thereby driving the track sliding block 8 to slide along the track groove 7, ultimately achieving angle adjustment of the ladder assembly. The gear transmission mechanism has high transmission accuracy, enabling precise control of the ladder angle, meeting the requirements of scenarios with high operational position accuracy. Simultaneously, the motor's drive method is convenient to operate, controllable via remote control or buttons, reducing manual operation intensity. Furthermore, the gear transmission mechanism can be equipped with a braking device. After the ladder is adjusted to the desired angle, the braking device locks the gear position, preventing the ladder from shifting due to external forces, further improving operational stability.

[0022] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adjustable height steel ladder, characterized in that, The system includes a ladder assembly, a support adjustment assembly, and a fall prevention mechanism. The upper end of the ladder assembly is hinged to the grain inspection platform, and the lower end is slidably connected to the support adjustment assembly. The ladder assembly can rotate within a range of 0° to 90° around the hinge point to adapt to different grain loading heights. The support adjustment assembly includes a track structure fixed to the wall and an adjustment mechanism that drives the ladder assembly to rotate. The track structure is connected to a pre-embedded part in the wall through an adjustable support member, which is used to calibrate the track structure to the same vertical plane. The fall prevention mechanism is connected to the lower end of the ladder assembly and is used to lock the position of the ladder assembly to prevent it from falling when the adjustment mechanism fails.

2. The adjustable height steel ladder according to claim 1, characterized in that, The ladder assembly includes a main ladder beam (1), a supporting ladder beam (2), a lower supporting beam (6), and treads (3). The main ladder beam (1) is symmetrically arranged on both sides of the treads (3). The treads (3) are arranged at equal intervals along the length of the main ladder beam (1), and both ends of the treads (3) are hinged to the main ladder beam (1). The supporting ladder beam (2) is located at the lower middle or both ends of the treads (3). The lower end of the ladder assembly is fixed with a lower supporting beam (6) perpendicular to the main ladder beam (1). The main ladder beam (1) is provided with a guardrail (5), and the end of the treads (3) is provided with a climbing bar (4).

3. The adjustable height steel ladder according to claim 1, characterized in that, The support adjustment assembly includes a track groove (7), a track sliding block (8), and a support member. The track groove (7) is an arc-shaped structure and is installed in the embedded part of the wall through the support member. The track sliding block (8) is rotatably mounted on the end of the lower support beam (6) of the ladder assembly, and the track sliding block (8) is locked in the track groove (7) and slides relative to the track groove (7).

4. The adjustable height steel ladder according to claim 3, characterized in that, The support includes a base sleeve (13), an adjusting screw (14), and two locking nuts (17). The base sleeve (13) is fixed to the wall embedded parts. One end of the adjusting screw (14) is connected to the track groove (7) through a fisheye bearing (15) and has a rotating end (16) at its end. The other end of the adjusting screw (14) is threadedly connected to the base sleeve (13). The locking nuts (17) are threadedly fitted on the adjusting screw (14). When the adjusting screw (14) is adjusted to the position, the locking nuts (17) press against the base sleeve (13) to achieve axial limiting of the adjusting bolt.

5. The adjustable height steel ladder according to claim 1, characterized in that, The adjustment mechanism includes an angle adjustment cable (9), a pulley (11) and a drive component. One end of the angle adjustment cable (9) is connected to the lower support beam (6) of the ladder assembly, and the other end passes through the pulley (11) on the roof and is connected to the drive component. The drive component is a manual winch or an electric winch.

6. The adjustable height steel ladder according to claim 1, characterized in that, The fall protection mechanism includes a safety fall arrestor (10) and a finished fall arrestor (12). The finished fall arrestor (12) is fixed to the roof or the bottom of the floor. One end of the safety fall arrestor (10) is connected to the lower end of the ladder assembly, and the other end is connected to the finished fall arrestor (12). The safety fall arrestor (10) adapts to the rotation of the ladder assembly.

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