A drawbar fixing device

Abstract

The utility model discloses a kind of traction rod fixing devices, including installation bottom plate, installation bottom plate top connects corresponding main cylinder and square column, and locking groove is opened in main cylinder side;Square column top swing groove, swing bar is connected in groove by rotating pin, and one end of lock swing bar is movably inserted into locking groove, and the other end passes through rotating pin and connects handle counterweight. The device replaces traditional wheel stop with mechanical locking, and the core component is of metal material and has a reinforced protection structure. It is suitable for a variety of traction rods, can improve the security and operation efficiency of fixation, ensure the safety of the parking apron, standardize equipment management, and is suitable for airport parking apron traction rod storage and fixation.

Description

Technical Field

[0001] This utility model relates to the field of airport ground equipment safety fixing technology, specifically to a tow bar fixing device. Background Technology

[0002] In airport ground operations, aircraft tow bars are one of the core pieces of equipment ensuring aircraft movement on the ground. Their main function is to connect the aircraft to the tow vehicle, enabling precise relocation of the aircraft in areas such as the apron and maintenance hangar. Because tow bars need to be frequently moved between different aircraft positions and are exposed to the outdoor environment of the apron for extended periods, the reliability of their secure storage directly affects the apron operation order, personnel safety, and equipment integrity, making them a key component of the airport ground safety management system.

[0003] Currently, most airports both domestically and internationally still primarily use traditional wheel stops to secure towbars. This method involves placing rubber or metal wheel stops on both sides of the towbar wheels, utilizing the friction between the wheel stops and the ground to restrict the movement of the towbar. While it boasts advantages such as simple structure and low initial investment cost, it has revealed several insurmountable drawbacks in practical application. Firstly, operation relies heavily on manual experience and adherence to standards. If operators fail to ensure the wheel stops are firmly against the wheel edges, fail to properly compact the wheel stops, or if wheel stops are misaligned when multiple towbars are stored, the wheel stops can easily shift under slight stress on the towbar, directly causing fixation failure and creating safety hazards. Secondly, they have extremely poor resistance to harsh environments. In weather conditions such as strong winds, heavy rain, snow, or high temperatures, the friction between the wheel chocks and the ground will decrease significantly. Rubber wheel chocks are prone to losing elasticity due to aging or hardening at low temperatures, while metal wheel chocks may slip due to wet ground. In some cases, the wheel chocks may even be blown over by strong winds or washed away by rainwater, ultimately causing the tow bar to slip and collide with apron signs, ground well equipment, jet bridges, or passing support vehicles, resulting in safety incidents such as equipment damage or personnel injury.

[0004] Furthermore, traditional wheel chock fixing methods suffer from both inadequate adaptability and management efficiency. On the one hand, different models of tow bars have varying wheel sizes and track widths, requiring wheel chocks of corresponding sizes for each tow bar specification. This not only increases airport equipment procurement costs but also necessitates additional manpower for the classification, storage, maintenance, and scheduling of wheel chocks, and can easily lead to fixing failure due to mismatched wheel chock specifications. On the other hand, the handling, placement, and removal of wheel chocks all require manual operation. Each fixing or unlocking process necessitates repeated adjustments to the wheel chock position, making the operation cumbersome and time-consuming. This makes it difficult to meet the needs of rapid tow bar scheduling during peak airport periods, indirectly affecting the efficiency of ground support operations.

[0005] With the civil aviation industry's continuous improvement in ground operation safety standards and the sustained growth of airport flight throughput, traditional wheel chock fixing methods are no longer adequate for the dual requirements of modern airports for equipment safety and management efficiency. Their inherent shortcomings, such as poor safety, weak anti-interference capabilities, and low adaptability, are becoming increasingly prominent. Therefore, there is an urgent need to design a reliable, adaptable, easy-to-operate, and environmentally friendly tow bar fixing device to address the deficiencies of existing technologies, fill the technological gap in airport tow bar safety fixing, and further improve the airport ground safety management system. Utility Model Content

[0006] The purpose of this utility model is to provide a tow bar fixing device to solve the problems of poor safety, weak resistance to environmental interference, low adaptability and low operating efficiency of the traditional wheel chock fixing method mentioned in the background art.

[0007] To achieve the above objectives, the present invention employs the following technical means:

[0008] A traction rod fixing device includes a mounting base plate. The top of the mounting base plate is connected to a corresponding main cylinder and a square column. Locking grooves are formed on opposite sides of the main cylinder and the square column. A swing groove is formed on the top of the square column. A locking swing rod is inserted into the swing groove and rotatably connected to the square column by a rotating pin. One end of the locking swing rod is movably inserted into the locking groove, and the other end of the locking swing rod is rotatably connected to a handle counterweight by a rotating pin.

[0009] Preferably, the mounting base plate, main cylinder, square column, rotating pin, locking lever, and handle counterweight are all made of metal.

[0010] Preferably, a base plate reinforcing rib connected to the mounting base plate is provided between the main cylindrical column and the square column.

[0011] Preferably, the mounting base plate has multiple sets of mounting holes.

[0012] Preferably, a cylindrical cover plate is connected to the opening at the top of the main cylinder.

[0013] Preferably, the locking lever engages with the locking groove when rotating forward, and disengages from the locking groove when rotating in reverse.

[0014] Preferably, the top of the handle counterweight is provided with a slot, and the other end of the locking lever is inserted into the slot and rotatably connected to the handle counterweight via a rotating pin.

[0015] This utility model has the following beneficial effects:

[0016] 1. Significantly improved safety: This device replaces the traditional wheel stop fixing method with a mechanical locking structure between the main cylinder and the locking swing rod. In the locked state, the tow rod connecting ring is firmly constrained between the main cylinder and the locking swing rod. Even in severe weather conditions such as strong winds and heavy rain, it can effectively prevent the tow rod from accidentally shifting or falling off, greatly reducing the safety risks on the helipad.

[0017] 2. Convenient and efficient operation: The locking process does not require manual intervention of the locking lever; simply inserting the traction rod connecting ring will automatically complete the locking. The unlocking process only requires turning the handle counterweight to release the constraint. The operation steps are simplified and can be completed by a single person. Compared with the traditional wheel stop fixing method, it greatly improves the work efficiency.

[0018] 3. Reliable and durable structure: All core components of the device are made of metal materials, and the strength of key parts is enhanced by the base plate reinforcing ribs. At the same time, the cylindrical cover plate can effectively protect the internal structure of the main cylinder, ensuring that the device can withstand environmental corrosion and mechanical wear during long-term outdoor use, resulting in a long service life.

[0019] 4. High adaptability: The diameter of the main cylinder and the size of the locking groove are designed to be compatible with the specifications of various tow bar connecting rings commonly used in airport aprons. There is no need to design separate fixing devices for different tow bar models, which improves the versatility of the device and reduces the procurement and maintenance costs of airport equipment.

[0020] 5. Improve management standardization: By using standardized fixing devices to centrally store tow poles, it is possible to ensure that the tow poles are placed neatly and uniformly, improve the storage order of apron equipment, and enhance the standardization and aesthetics of airport ground management. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a cross-sectional view of the present invention;

[0023] In the attached figures, the following labels are used:

[0024] 1. Base plate; 2. Base plate reinforcing rib; 3. Mounting hole; 4. Main cylinder; 5. Locking groove; 6. Cylinder cover plate; 7. Square column; 8. Swing groove; 9. Rotating pin; 10. Locking swing rod; 11. Slot; 12. Handle counterweight. Detailed Implementation

[0025] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] like Figure 1-2 As shown, a traction rod fixing device includes a mounting base plate 1. A main cylindrical column 4 and a square column 7, which are symmetrically distributed, are fixedly connected to the top of the mounting base plate 1. Locking grooves 5 are opened on the opposite sides of the main cylindrical column 4 and the square column 7. A swing groove 8 is opened on the top of the square column 7. A locking swing rod 10 is inserted into the swing groove 8, and the locking swing rod 10 is rotatably connected to the square column 7 through a rotating pin 9. One end of the locking swing rod 10 is movably inserted into the locking groove 5 on the side of the main cylindrical column 4, and the other end of the locking swing rod 10 is rotatably connected to a handle counterweight 12 through a rotating pin 9.

[0027] The mounting base plate 1, main cylinder 4, square column 7, rotating pin 9, locking lever 10, and handle counterweight 12 are all made of metal to ensure the overall structural strength and corrosion resistance of the device.

[0028] A base plate reinforcing rib 2, connected to the mounting base plate 1, is provided between the main cylindrical column 4 and the square column 7. The base plate reinforcing rib 2 is distributed on the mounting base plate 1 to enhance its strength and rigidity, further improving the overall stability and reliability of the device. Through reasonable layout and design, the base plate reinforcing rib 2 can effectively disperse stress, reducing the risk of deformation of the mounting base plate 1 during long-term use.

[0029] The mounting base plate 1 has multiple sets of mounting holes 3 arranged in a matrix. The mounting holes 3 are through round holes. The mounting base plate 1 is fixedly connected to the ground of the helipad by expansion bolts passing through the mounting holes 3, so as to ensure that the device will not be displaced during use.

[0030] A cylindrical cover plate 6 is fixedly connected to the top opening of the main cylinder 4. The cylindrical cover plate 6 is made of thick steel plate, and the diameter of the cylindrical cover plate 6 is adapted to the outer diameter of the main cylinder 4. It is fixed to the top of the main cylinder 4 by welding or bolt connection to prevent dust, rainwater, debris and other objects from entering the interior of the main cylinder 4, avoid internal corrosion or blockage, and extend the service life of the device.

[0031] The top of the handle counterweight 12 has a slot 11, and the other end of the locking lever 10 is inserted into the slot 11. The rotating pin 9 passes through the insertion part of the handle counterweight 12 and the locking lever 10 to realize the rotational connection between the two. The outer wall of the handle counterweight 12 is provided with anti-slip texture, and its weight is adapted to the gravity lever requirement of the locking lever 10, ensuring that the operator can easily overcome the locking gravity of the locking lever 10 and complete the unlocking operation.

[0032] The working state of the locking lever 10 satisfies the following conditions: when the locking lever 10 rotates clockwise around the rotating pin 9, its end engages with the locking groove 5 of the main cylinder 4, forming a lock on the traction rod connecting ring; when the locking lever 10 rotates counterclockwise around the rotating pin 9, its end disengages from the locking groove 5, releasing the constraint on the traction rod.

[0033] Working principle

[0034] This device achieves automatic locking and convenient unlocking of the traction rod based on the principle of gravity lever. Its core function is accomplished through the coordinated action of the main cylinder 4, locking lever 10, rotating pin 9, and handle counterweight 12. The specific process is as follows:

[0035] 1. Locking process

[0036] Positioning and insertion: The operator aligns the connecting ring at the head of the traction rod with the axis of the main cylinder 4 and slowly moves it downwards, so that the connecting ring is gradually inserted into the outer side of the main cylinder 4.

[0037] Passive opening of the locking lever: When the connecting ring moves down to the end of the locking lever 10 that is close to the main cylinder 4, the continuous downward pressure of the connecting ring will push the locking lever 10 to rotate downward around the rotating pin 9 on the square column 7. At this time, the locking lever 10 disengages from the locking groove 5 of the main cylinder 4. The swing groove 8 provides room for the rotation of the locking lever 10, ensuring that the connecting ring can continue to move down.

[0038] Automatic reset locking: When the connecting ring is fully inserted into the bottom of the main cylinder 4, the downward pressure of the connecting ring on the locking lever 10 disappears; at this time, under the action of its own weight and the lever gravity of the handle counterweight 12, the locking lever 10 automatically rotates upward around the rotating pin 9, and its end is reinserted into the locking groove 5 of the main cylinder 4, forming a circumferential limit on the connecting ring - the connecting ring is constrained in the space enclosed by the main cylinder 4, the locking lever 10 and the mounting base plate 1, and cannot be disengaged upward or moved laterally, thus completing the locking and fixing of the traction rod.

[0039] 2. Unlocking process

[0040] External force-driven unlocking: The operator holds the counterweight 12 on the handle and applies rotational force in a direction away from the main cylinder 4;

[0041] Locking lever releases from constraint: The handle counterweight 12 drives the locking lever 10 to rotate downward around the rotating pin 9 on the square column 7 via the rotating pin 9, so that the end of the locking lever 10 inserted into the locking groove 5 is completely released, thus releasing the circumferential constraint on the connecting ring.

[0042] Remove the traction rod: Keep the handle counterweight 12 in a rotating state, pull the traction rod upward to disengage the connecting ring along the axis of the main cylinder 4, and the unlocking will be completed; after releasing the handle counterweight 12, the locking lever 10 will automatically reset under the action of gravity, waiting for the next locking operation.

[0043] Example 1

[0044] General-purpose airport apron tow bar fixing device

[0045] 1. Applicable Scenarios

[0046] The general-purpose parking aprons at medium-sized domestic airports are used to store tow bars for mainstream aircraft models. There is no extreme weather, and the ease of operation and cost control must be taken into account.

[0047] 2. Structural and Parametric Design

[0048] Installation base plate 1: The material is Q235 low carbon steel plate, and the key dimensions are length × width × thickness = 400mm × 300mm × 12mm; the process is to use sandblasting to remove rust, and then spray epoxy zinc-rich primer and polyurethane topcoat in sequence. Anti-slip texture is reserved on the bottom to enhance the friction with the ground.

[0049] Base plate reinforcing rib 2: Made of Q235 steel plate, it has a rectangular plate structure and is fully welded to the mounting base plate 1. The weld height is 6mm. After welding, the weld is ground to ensure a smooth surface and avoid stress concentration.

[0050] Mounting hole 3: The hole diameter is 16mm, and there are 4 sets in a rectangular distribution; the hole wall is chamfered at 45° to prevent scratching the bolt threads when installing expansion bolts and to improve the ease of installation.

[0051] Main cylinder 4: Made of 20# seamless steel pipe, with an outer diameter of 120mm, a height of 200mm, and a wall thickness of 8mm; the inner wall is phosphated and connected to the mounting base plate 1 by submerged arc welding with a welding depth of not less than 10mm to ensure connection strength.

[0052] Locking groove 5: 18mm wide, 20mm deep, and 50mm high from the top surface of the mounting base plate; the edges of the groove are rounded to prevent scratching the traction rod connecting ring when the traction rod is put in or taken out.

[0053] Cylindrical cover plate 6: Made of Q235 steel plate, 120mm in diameter and 6mm in thickness; it is fixed to the top of the main cylinder 4 by argon arc welding. A 5mm diameter drainage hole is reserved in the center of the cover plate to prevent rainwater from accumulating inside the main cylinder.

[0054] Square column 7: The material is Q235 square steel, with a cross-sectional size of 80mm×80mm, a height of 220mm, and a wall thickness of 6mm; it is fully welded to the mounting base plate 1, with a weld height of 5mm. The surface treatment process is the same as that of the mounting base plate 1 to ensure a uniform overall appearance and rust prevention performance.

[0055] Slot 8: 19mm wide, 40mm deep, and 30mm high from the top of the square column; the slot wall is milled, and the surface roughness is controlled to Ra≤3.2μm to ensure that the locking rod rotates smoothly in the slot without jamming.

[0056] Rotating pin 9: Made of 45# steel, 16mm in diameter and 100mm in length; chrome-plated surface, and fixed at both ends with 3mm diameter cotter pins in accordance with GB / T91-2000 standard to prevent the rotating pin from loosening and falling off during use.

[0057] Locking rod 10: Made of Q345 steel plate, 280mm in length, 50mm in width, and 17mm in thickness; the surface treatment process is the same as that of the mounting base plate 1, with the end near the main cylinder 4 rounded to prevent jamming with the traction rod connecting ring during the locking process.

[0058] Slot 11: 18mm wide, 35mm deep, and 20mm high from the top surface of the handle counterweight; the slot wall is formed by milling, and the clearance between it and the locking lever 10 is controlled to ≤0.5mm to ensure a tight connection and efficient transmission.

[0059] Handle counterweight 12: Made of gray cast iron HT200, length × width × height = 150mm × 80mm × 60mm, weight 1.2kg; the outer wall is rolled with anti-slip texture, the surface is painted, and a 3mm diameter hole is reserved in the center to reduce the overall weight while ensuring the operating feel.

[0060] 3. Implementation of core functions

[0061] When locking, align the connecting ring of the tow rod with the main cylinder 4 and insert it. As the connecting ring moves downward, it pushes the locking lever 10 to open around the rotating pin 9. When the connecting ring is fully inserted into the bottom of the main cylinder 4 and fits against the mounting base plate 1, the locking lever 10 automatically resets under its own weight and the action of the handle counterweight 12, and its end inserts into the locking groove 5, thus achieving vertical and lateral constraint on the connecting ring. When unlocking, hold the handle counterweight 12 and rotate it 30°-45° away from the main cylinder 4 to drive the locking lever 10 out of the locking groove 5. Then, pull the tow rod upward to remove it. The coating system of this device can meet the outdoor rust prevention requirements for more than 5 years, and the welded structure has a load-bearing capacity of not less than 5kN, far exceeding the self-weight of the tow rod and the conventional wind load, and is compatible with most conventional tow rods.

[0062] Example 2

[0063] Specialized traction rod fixing device for highly corrosive environments

[0064] 1. Applicable Scenarios

[0065] Coastal airport aprons are subject to the long-term influence of the maritime climate, so it is necessary to focus on improving the corrosion resistance of components and adapt them to heavy-duty tow bars with anti-corrosion coatings.

[0066] 2. Structural and Parameter Design (Only the differences from Example 1 are listed)

[0067] Mounting base plate 1: The material has been changed to 316L stainless steel plate, the surface is passivated, and the anti-slip texture on the bottom is formed by laser engraving; the salt spray resistance of 316L stainless steel is more than 10 times that of Q235, and the passivation treatment can further improve the resistance to pitting corrosion, making it suitable for highly corrosive coastal environments.

[0068] Main cylinder 4: The material has been changed to 316L stainless steel seamless tube, and the inner wall is electrolytically polished; the stainless steel material avoids corrosion caused by water accumulation on the inner wall, and the larger outer diameter is suitable for the larger connecting ring of the heavy-duty tow bar. Electrolytic polishing can reduce the adhesion of impurities.

[0069] Rotating pin 9: The material has been changed to Hastelloy C276, with no coating on the surface, and stainless steel elastic retaining rings are used to fix both ends; Hastelloy can withstand long-term salt spray immersion, and the elastic retaining rings prevent the cotter pin from failing after corrosion, thus improving the long-term reliability of rotating parts.

[0070] Handle counterweight 12: The material has been changed to 316L stainless steel with a brushed finish and anti-slip texture formed by stamping. Stainless steel has no risk of rust, and the brushed surface can still maintain good grip in humid environments to avoid slipping.

[0071] Additional structure: A stainless steel waterproof cover is added to the top of the square column 7 and fixed to the square column (7) by welding, completely covering the swing groove 8 and the rotating pin 9; it can prevent rainwater and salt spray from directly entering the swing groove 8 and avoid the locking rod 10 and the rotating pin 9 from being blocked due to corrosion.

[0072] 3. Corrosion resistance performance verification

[0073] According to GB / T 10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test", a neutral salt spray test was conducted. After 1000 hours of continuous testing, all metal parts showed no obvious rust or coating peeling, and the rotational resistance of the locking swing rod 10 did not change by more than 10%. When adapted to a heavy-duty traction rod, the main cylinder 4 has a load-bearing capacity of not less than 8kN, meeting a safety factor of 2.5, and can be used stably in a highly corrosive coastal environment for a long time.

[0074] Example 3

[0075] Traction bar fixing device in low temperature and frigid regions

[0076] 1. Applicable Scenarios

[0077] Airports in frigid northern regions, where winter temperatures can drop to -30°C and snow and ice accumulate, require special tow bars with heating functions to prevent components from freezing and jamming.

[0078] 2. Structural and Parameter Design (Only the differences from Example 1 are listed)

[0079] Locking rod 10: The material is changed to Q355ND low-temperature toughness steel plate. A 4mm diameter oil injection hole is reserved at the mating point between the locking rod 10 and the rotating pin 9. Q355ND has an impact energy of not less than 34J at -40℃, which can avoid low-temperature brittle fracture. Low-temperature grease can be injected into the oil injection hole regularly to prevent the rotating parts from freezing due to low temperature.

[0080] Rotating pin 9: The surface is nitrided, and the fit clearance with the locking lever 10 is increased to 1mm; the nitrided layer improves the surface wear resistance, and the increased fit clearance can offset the metal shrinkage at low temperatures, ensuring that the locking lever 10 rotates flexibly in low-temperature environments.

[0081] Installation base plate 1: Stainless steel anti-slip protrusions are added to the bottom, and the surface coating is changed to low-temperature curing polyurethane; the anti-slip protrusions can enhance the friction with the icy ground and prevent the entire device from shifting. The low-temperature curing coating allows for construction in winter without waiting for a high-temperature environment.

[0082] Handle counterweight 12: The inner part is pre-embedded with a low-temperature resistant rubber sleeve, and the outer part is wrapped with a removable non-slip fleece cloth; the combination of rubber sleeve and fleece cloth can prevent operators from getting frostbite when holding it in winter, while increasing grip friction at low temperatures, eliminating the risk of slipping, and the removable fleece cloth is easy to clean and replace.

[0083] Additional structure: A heat tracing cable is wrapped around the outside of the main cylinder 4, and the heat tracing cable is wrapped with flame-retardant insulation cotton; the temperature controller is set to a temperature range of 0℃~5℃, and the heat tracing is automatically activated when the temperature is below 0℃ in winter to prevent the main cylinder 4 from freezing and the connecting ring of the traction rod to ensure smooth unlocking.

[0084] 3. Low-temperature performance verification

[0085] After standing for 24 hours at -35℃, the rotational resistance of the locking lever 10 does not exceed 30N. Within 30 minutes after the heating cable is started, the surface temperature of the main cylinder 4 rises to above 5℃ without icing. Under snow cover, the anti-slip protrusions of the mounting base plate 1 can provide a friction coefficient of not less than 1.2, the device has no risk of displacement, the traction rod is locked stably, and it is suitable for use in the winter in the cold northern regions.

[0086] The examples provided in this utility model are not intended to limit the implementation methods. Those skilled in the art will recognize that various variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementation methods here, and any obvious variations or modifications derived therefrom are still within the protection scope of this utility model.

Claims

1. A traction rod fixing device, characterized in that, The system includes a mounting base plate (1), on the top of which are connected corresponding main cylinders (4) and square columns (7). Locking grooves (5) are provided on opposite sides of the main cylinders (4) and square columns (7). A swing groove (8) is provided on the top of the square columns (7). A locking swing rod (10) is inserted into the swing groove (8) and rotatably connected to the square columns (7) via a rotating pin (9). One end of the locking swing rod (10) is movably inserted into the locking groove (5), and the other end of the locking swing rod (10) is rotatably connected to a handle counterweight (12) via a rotating pin (9).

2. The traction rod fixing device according to claim 1, characterized in that, The mounting base plate (1), main cylinder (4), square column (7), rotating pin (9), locking lever (10), and handle counterweight (12) are all made of metal.

3. The traction rod fixing device according to claim 1, characterized in that, The main cylindrical column (4) and the square column (7) are provided with a base plate reinforcing rib (2) that is connected to the mounting base plate (1).

4. The traction rod fixing device according to claim 1, characterized in that, The mounting base plate (1) has multiple sets of mounting holes (3).

5. A traction rod fixing device according to claim 1, characterized in that, A cylindrical cover plate (6) is connected to the opening at the top of the main cylinder (4).

6. The traction rod fixing device according to claim 1, characterized in that, The locking lever (10) rotates forward and engages with the locking groove (5), and the locking lever (10) rotates backward and disengages from the locking groove (5).

7. A traction rod fixing device according to claim 1, characterized in that, The top of the handle counterweight (12) is provided with a slot (11), and the other end of the locking lever (10) is inserted into the slot (11) and rotatably connected to the handle counterweight (12) through a rotating pin (9).

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