Mechanical state memory automatic release hook based on rotating logic cam

Abstract

The application discloses a mechanical state memory automatic release hook based on a rotating logic cam, which comprises a main force-bearing hook body, a movable main lock pin is arranged at a hook opening of the main force-bearing hook body, a state sensing plunger is arranged to be slidable along an axial direction and is provided with a spring to make the state sensing plunger have an outward extending tendency, the state sensing plunger is configured to be compressed to a pressed-in position when an outward pulling force is borne, and to move to a pop-out position under the action of the spring when the pulling force disappears, a rotating logic cam is arranged to be rotatable around an axis, and a trigger connecting rod is connected between the main force-bearing hook body and the main lock pin, wherein the state sensing plunger is coupled with the rotating logic cam, so that when the state sensing plunger moves from the pressed-in position to the pop-out position, the rotating logic cam is driven to rotate from a first angle position to a second angle position. The application has the advantages of pure mechanical driving, reliable state judgment, mechanical memory function and operation safety.

Description

Technical Field

[0001] This invention relates to the field of mechanical control technology, specifically to a mechanical state memory automatic release hook based on a rotary logic cam. Background Technology

[0002] In fields such as drone hoisting, field rescue, and special logistics, achieving reliable automatic release of loads is a key technology. Currently, mainstream automatic release devices generally adopt control schemes based on electronic sensors. This scheme typically monitors the force on the sling through a tension sensor. When the tension is detected to drop to near zero, the controller drives a motor or electromagnet to perform the unlocking action.

[0003] However, such electronic solutions have several inherent defects in practical applications: First, their release judgment depends on a specific tensile force threshold. When hoisting light loads, the load's own weight is close to noise signals such as flight vibration and wind disturbance, making it difficult for sensors to accurately distinguish them, which can easily lead to "light load failure". Second, when the load lands on uneven ground (such as slopes or grass), the sling may still be partially taut, and the tension may not return to zero, causing the device to "refuse to release". Third, the reliability of the electronic components of the entire system drops sharply in harsh environments such as humidity, high and low temperatures, rain and snow, and strong electromagnetic interference, posing a risk of "environmental failure". In addition, the system always relies on external power supply, which increases the overall complexity and potential failure points.

[0004] To improve environmental adaptability, some purely mechanical triggering mechanisms exist in the industry, such as devices that trigger when a probe touches the ground. However, these mechanisms usually lack state latching capabilities and may be accidentally released if they accidentally touch an obstacle during flight, resulting in insufficient safety.

[0005] Therefore, there is an urgent need in the field for a fully mechanical automatic release device that does not rely on electricity and electronic sensing, can intelligently determine the "true landing state" and securely lock the state, and finally release it after confirmation. Summary of the Invention

[0006] The purpose of this invention is to provide a mechanical state memory automatic release hook based on a rotary logic cam, which has the advantages of pure mechanical drive, reliable state judgment, mechanical memory function and safe operation, and solves the problems in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An automatic release hook based on a rotary logic cam with mechanical state memory includes: The main load-bearing hook body has a movable main locking pin at its hook opening; A status-sensing plunger is slidably disposed along the axial direction and is configured with a spring that gives it an outward extension tendency. The status-sensing plunger is configured to be compressed to an indented position when subjected to an outward pulling force and to move to an ejected position under the action of the spring when the pulling force is removed. A rotary logic cam, which can be rotatably set about an axis; A trigger linkage connects the main load-bearing hook body to the main locking pin; The state-sensing plunger is coupled to the rotary logic cam, such that when the state-sensing plunger moves from the pressed-in position to the ejected position, it drives the rotary logic cam to rotate from the first angle position to the second angle position. When the rotary logic cam is in the first angular position, its structure restricts the movement of the trigger linkage, keeping the main locking pin in a locked state. When the rotary logic cam is in the second angle position, its structure allows the trigger linkage to move when the main load-bearing hook body is under tension, thereby driving the main locking pin to move and unlock.

[0008] Preferably, the state-sensing plunger is coupled to the rotary logic cam through a pawl and ratchet meshing structure, and the movement of the state-sensing plunger from the pressed position to the ejected position drives the rotary logic cam to rotate unidirectionally through the meshing structure.

[0009] Preferably, the preset angle of rotation of the rotary logic cam is 30 degrees.

[0010] It is worth noting that the profile of the rotary logic cam physically interferes with the corresponding part of the trigger link at the first angular position to limit its movement in the unlocking direction; at the second angular position, the profile disengages from the interference with the corresponding part of the trigger link, providing travel space for its movement in the unlocking direction. This design achieves precise switching between locking and unlocking through purely mechanical profile interference, without the involvement of electronic components, resulting in strong structural stability and effectively avoiding the risk of unexpected unlocking or unlocking failure. In the locked state, the rigid limit of the physical interference can withstand complex working conditions such as vibration and impact during hoisting, ensuring reliable load locking; in the unlocked state, the effective travel space formed after the profile disengages from the interference ensures smooth movement of the trigger link, driving the main locking pin to unlock quickly, improving the timeliness and accuracy of load release, and adapting to the usage requirements of various harsh hoisting scenarios.

[0011] Preferably, it further includes a reset mechanism for driving the rotary logic cam to reset from the second angular position to the first angular position after the main locking pin is unlocked and the load is released.

[0012] It is worth noting that the reset mechanism enables the device to be used repeatedly without manual reset, significantly improving operational efficiency and ease of operation. After the load is released, the reset mechanism automatically drives the rotating logic cam back to the initial locking limit state, allowing the device to quickly return to the ready-to-lift state, meeting the needs of continuous lifting operations. This is particularly suitable for remote operation scenarios such as those involving drones, avoiding the risks and inconvenience of manual approach for reset. Furthermore, the automatic reset mechanism ensures consistent locking reliability for each lifting operation, reducing safety hazards caused by human error and extending the device's service life and operational stability.

[0013] Preferably, the reset mechanism is one of a torsion spring, a tension spring, or a gravity lever mechanism.

[0014] It is worth noting that using torsion springs, tension springs, or gravity lever mechanisms as the reset mechanism offers significant advantages such as simple structure, low cost, high reliability, and convenient maintenance. These mechanisms are all mature, purely mechanical structures with no complex transmission components, resulting in fewer potential failure points. They can adapt to various harsh environments, including high and low temperatures, humidity changes, vibration, and shock, avoiding the aging and failure issues of electronic reset components. Furthermore, the three mechanisms offer flexibility in selection, adapting to the overall structural layout of the device, installation space, and reset force requirements. Torsion springs and tension springs are compact and occupy little space, while gravity lever mechanisms require no additional elastic elements, making them suitable for different design scenarios. This ensures precise and stable reset actions, guaranteeing the consistency and reliability of the device during repeated use.

[0015] Preferably, the actions of the state-sensing plunger, the rotary logic cam, the trigger linkage, and the reset mechanism do not depend on electronic sensors, electronic controllers, or external power sources.

[0016] It is worth noting that this purely mechanical drive design completely eliminates reliance on electronic components and external power supplies, significantly improving the device's anti-interference capabilities and environmental adaptability. Under harsh conditions such as strong electromagnetic interference, high temperatures, low temperatures, humidity, and dust, it avoids device failure caused by electronic sensor malfunctions, controller failures, or power outages, ensuring precise and controllable load locking and releasing actions. Simultaneously, the elimination of the need for additional power supply modules and electronic control units simplifies the device structure, reduces manufacturing costs and maintenance difficulty, and improves the device's reliability and lifespan. It is particularly suitable for scenarios with extremely high requirements for equipment stability and independence, such as drone hoisting and outdoor operations, ensuring operational safety and efficiency.

[0017] Preferably, the axial sliding direction of the state-sensing plunger is perpendicular to the main load-bearing plane of the main load-bearing hook body.

[0018] It is worth noting that this axial sliding direction design effectively avoids interference between the force on the state-sensing plunger and the load-bearing force on the main load-bearing hook, improving the sensitivity and accuracy of state sensing. The force exerted by the main load-bearing hook under load is transmitted along the main load-bearing plane, while the state-sensing plunger slides perpendicular to this plane. This prevents lateral forces or impacts generated during load-bearing from mistakenly triggering the state-sensing plunger's action, ensuring it only responds to preset outward tension signals. Simultaneously, the vertical layout optimizes the internal structural space of the device, making the layout of each component compact and reasonable, reducing space occupation, and adapting to application scenarios such as drones where there are strict limitations on equipment size and weight, thus improving the assembly flexibility and overall structural stability of the device.

[0019] Preferably, the main load-bearing hook, the status-sensing plunger, the rotary logic cam, and the trigger linkage are made of high-strength stainless steel or aerospace aluminum alloy.

[0020] It is worth noting that using high-strength stainless steel or aerospace-grade aluminum alloy as the core component material can simultaneously meet the multiple requirements of the device for strength, corrosion resistance, and lightweight. High-strength stainless steel has excellent tensile strength and corrosion resistance, which can withstand the load impact during hoisting and the corrosion of the outdoor environment. Aerospace-grade aluminum alloy has high strength and low density, which can reduce the overall weight of the device while ensuring the structural load-bearing capacity. It is suitable for scenarios such as drone hoisting where the weight of the equipment is sensitive. Both materials have mature processing technology and stable mechanical properties, which can ensure that the components are not easily deformed or damaged during long-term cyclic use, improve the load-bearing capacity and service life of the device, and ensure the structural safety and reliability during load hoisting.

[0021] Preferably, it is used in drone lifting systems as an automatic load release device.

[0022] It is worth noting that applying this device to a drone lifting system precisely matches the core requirements of drone lifting for automatic release devices. Since drones have limited load capacity, the device's lightweight design reduces the impact on drone endurance. The high reliability and anti-interference capabilities of the purely mechanical structure can adapt to vibrations, attitude changes during drone flight, and complex outdoor environments. Automatic locking, sensor-triggered release, and automatic reset functions enable automated and remote operation of load lifting without manual intervention, improving operational efficiency and safety. This device is widely applicable to drone lifting scenarios such as logistics transportation, emergency rescue, and outdoor exploration, enabling precise and safe release of loads of varying weights, thus expanding the application scope and practical value of drone lifting systems.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By setting up a state-sensing plunger, a rotary logic cam, and a trigger linkage with a purely mechanical structure, this invention completely eliminates the dependence on electronic sensors, controllers, and external power supplies. It effectively solves the problem that electronic solutions in the background technology are prone to failure in harsh environments such as strong electromagnetic interference, high and low temperatures, and humidity. Each component achieves action transmission through mechanical coupling, eliminating the risk of aging or failure of electronic components and significantly improving the reliability and environmental adaptability of the device under complex working conditions. 2. This invention utilizes a state-sensing plunger to mechanically sense changes in tension (compression when under tension, ejection when tension disappears), and in conjunction with a ratchet and pawl meshing structure to drive a rotating logic cam to rotate in one direction, thereby achieving mechanical memory and accurate judgment of the "real landing state". This solves the problems of "light load failure" and "refusal to release" when the load lands on uneven ground caused by electronic solutions relying on tension thresholds. This mechanical sensing logic does not rely on numerical judgment, but only responds to the physical state of tension disappearing after the load lands, ensuring the accuracy and timeliness of the release action. 3. This invention achieves reliable maintenance of the locked state by physically interfering with and limiting the trigger link at the first angular position through a rotating logic cam. This solves the safety hazard of existing pure mechanical triggering mechanisms lacking state locking capability and being prone to accidental release due to accidental contact with obstacles. Only when the state sensing plunger pops out and drives the cam to rotate to the second angular position is the trigger link allowed to move and unlock, forming a mechanical logic of "state confirmation - unlocking permission", which greatly improves the safety of the hoisting process. 4. By setting a reset mechanism such as a torsion spring, tension spring, or gravity lever mechanism, the present invention automatically drives the rotating logic cam to reset to the initial locked position after the load is released, so that the device can quickly return to the ready-to-lift state without manual reset. This solves the problem of insufficient convenience of existing devices for repeated use. It is especially suitable for remote operation scenarios such as drones, avoiding the risks and inconveniences of manual approach reset, improving continuous operation efficiency, and reducing human operation errors. Attached Figure Description

[0024] Figure 1 The diagram shown is a schematic representation of the overall three-dimensional structure of the present invention; Figure 2 The diagram shown is a three-dimensional internal mechanical structure of the present invention in the "lifting / standby state (rotating logic cam is in the first angle position)"; Figure 3 The diagram shown is a three-dimensional internal mechanical structure of the present invention in the "landing / armed state (rotary logic cam in the second angle position)"; Figure 4 The diagram shown is a three-dimensional internal mechanical structure of the present invention in the "pull-up / release state (main locking pin unlocked)"; Figure 5 The diagram shown is a plan view of the entire invention. Figure 6 The diagram shown is a plan view of the internal mechanism of the present invention in the "lifting / standby state (rotary logic cam is in the first angle position)"; Figure 7 The diagram shown is a plan view of the internal mechanism of the invention in the "landing / armed state (rotary logic cam in the second angle position)"; Figure 8 The diagram shown is a plan view of the internal mechanism of the present invention in the "pull-up / release state (main lock pin unlocked)".

[0025] Reference numerals: 10, main load-bearing hook body; 11, main locking pin; 20, status sensing plunger; 21, spring; 30, rotary logic cam; 40, trigger linkage. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] To address the issues of light-load and uneven ground failures caused by the reliance on specific tensile thresholds in existing electronic solutions, as well as their poor reliability and power dependence in harsh environments, and to overcome the safety defects of simple mechanical triggering mechanisms such as lack of state latching and susceptibility to false triggering, the following technical solution is proposed. Please refer to [link / reference]. Figures 1-8 ; An automatic release hook based on a rotary logic cam with mechanical state memory includes: a main load-bearing hook body 10, the hook opening of which is provided with a movable main locking pin 11; a state-sensing plunger 20, slidably disposed along the axial direction, and configured with a spring 21 that gives it an outward extension tendency, the state-sensing plunger 20 being configured to be compressed to a pressed-in position when subjected to an outward pulling force, and to move to a pop-out position under the action of the spring 21 when the pulling force disappears; a rotary logic cam 30, rotatably disposed about an axis; and a trigger link 40 connecting the main load-bearing hook body 10 and the main locking pin 11; wherein, the state-sensing plunger 20... The 0 is coupled with the rotary logic cam 30, such that when the state sensing plunger 20 moves from the pressed position to the pop-out position, it drives the rotary logic cam 30 to rotate from the first angle position to the second angle position; when the rotary logic cam 30 is in the first angle position, its structure restricts the movement of the trigger link 40, keeping the main locking pin 11 in a locked state; when the rotary logic cam 30 is in the second angle position, its structure allows the trigger link 40 to move when the main load-bearing hook 10 is subjected to tension, thereby driving the main locking pin 11 to move and unlock.

[0028] In this embodiment, specifically, the state-sensing plunger 20 is coupled to the rotary logic cam 30 through a pawl and ratchet meshing structure. The movement of the state-sensing plunger 20 from the pressed position to the ejected position drives the rotary logic cam 30 to rotate unidirectionally through the meshing structure.

[0029] In this embodiment, specifically, the preset angle of rotation of the rotary logic cam 30 is 30 degrees.

[0030] In this embodiment, specifically, the profile of the rotary logic cam 30 physically interferes with the corresponding part of the trigger link 40 at the first angular position to restrict its movement in the unlocking direction; at the second angular position, the profile disengages from the interference with the corresponding part of the trigger link 40, providing travel space for its movement in the unlocking direction.

[0031] In this embodiment, specifically, a reset mechanism is also included, which is used to drive the rotary logic cam 30 to reset from the second angle position to the first angle position after the main locking pin 11 is unlocked and the load is released.

[0032] In this embodiment, specifically, the reset mechanism is one of a torsion spring, a tension spring, or a gravity lever mechanism.

[0033] In this embodiment, specifically, the actions of the state sensing plunger 20, the rotary logic cam 30, the trigger linkage 40, and the reset mechanism do not depend on electronic sensors, electronic controllers, or external power supplies.

[0034] In this embodiment, specifically, the axial sliding direction of the state-sensing plunger 20 is perpendicular to the main load-bearing plane of the main load-bearing hook body 10.

[0035] In this embodiment, specifically, the main load-bearing hook 10, the status sensing plunger 20, the rotary logic cam 30, and the trigger linkage 40 are made of high-strength stainless steel or aerospace aluminum alloy.

[0036] In this embodiment, it is specifically applied to a drone hoisting system as an automatic load release device.

[0037] Example 1: UAV Medical Sample Lifting Example Using Pawl-Ratchet Coupling + Torsion Spring Reset Technical Solution Details: This embodiment is applicable to the scenario of light-load lifting of medical samples such as blood samples and vaccines by drones, and focuses on solving the problem of "light-load failure".

[0038] Coupling structure: The lower end of the state-sensing plunger 20 is provided with an arc-shaped ratchet with a tooth height of 2mm and a tooth pitch of 5mm. The edge of the rotary logic cam 30 is provided with a matching ratchet ring with 12 teeth. The ratchet and ratchet mesh to ensure that when the state-sensing plunger 20 pops out from the pressed position, the driving cam rotates 30° in one direction, corresponding to a meshing stroke of 1 tooth pitch, which is reliable and has no backlash.

[0039] Reset Mechanism: A torsion spring is used as the reset mechanism. The torsion spring is sleeved on the rotating shaft of the rotary logic cam 30, and the initial preload torque is 1.5 N·m. When the main locking pin 11 is unlocked and the load is released, the elastic restoring force of the torsion spring drives the cam to automatically reset from the second angle position armed position to the first angle position safe position. The reset time is ≤0.3s, realizing rapid cyclic use.

[0040] Materials and Dimensions: The main load-bearing hook body 10 is forged from 304 high-strength stainless steel in one piece, with a hook opening of 50mm and a rated load of 5kg; the status sensing plunger 20 is made of aviation aluminum alloy 6061, with a diameter of 12mm and a sliding stroke of 20mm; the spring 21 is a stainless steel tension spring with a preload of 0.8N. The overall weight is ≤300g, suitable for mounting on small drones.

[0041] Installation and adaptation: The axial sliding direction of the status sensing plunger 20 is strictly perpendicular to the bearing plane of the main bearing hook 10 with a vertical deviation of ≤±1°, to avoid false triggering caused by vibration during hoisting.

[0042] Applicable scenarios and advantages: This embodiment is specifically designed for light-load lifting scenarios such as medical samples. The purely mechanical structure is not affected by low temperatures of 20°C to 50°C and humid environments, and the release success rate is ≥99.8%, which completely solves the failure problem of the electronic control scheme under light-load conditions.

[0043] Example 2: UAV Mountain Rescue Implementation with Rack and Pinion Coupling + Tension Spring Reset Technical Solution Details: This embodiment is applicable to drone rescue missions in complex terrains such as mountains and plateaus, and focuses on solving the problem of "failure due to uneven ground".

[0044] Coupling structure: The side of the state-sensing plunger 20 is machined with a straight rack with a module of 1.5 and 8 teeth. A rotary logic cam 30 is coaxially fixed with a gear with a module of 1.5 and 12 teeth. The rack and gear mesh to drive the transmission. When the plunger pops out, it drives the cam to rotate 45°, increasing the stroke space of the trigger linkage 40 by ≥15mm and improving the fault tolerance of the release action.

[0045] Reset Mechanism: A stainless steel tension spring is used as the reset mechanism. One end of the spring is fixed to the device housing, and the other end is connected to the cam extension arm. The reset tension is adjustable to 23N to accommodate different rescue load weights, such as stretchers and supply packs.

[0046] Materials and Structure: The main load-bearing hook body 10 is made of aviation-grade aluminum alloy 7075 with a tensile strength ≥500MPa, a hook opening of 80mm, and a rated load of 30kg. The sliding direction of the status-sensing plunger 20 is inclined at a 60° angle to the load-bearing plane to avoid false triggering caused by sling tilting on sloping terrain. The triggering link 40 adopts a double-link hinge structure to enhance motion stability.

[0047] Applicable scenarios and advantages: Suitable for uneven ground scenarios such as mountain rescue. The rack and pinion transmission has high precision with a rotation angle error of ≤±1°. The tension spring reset mechanism has a fatigue service life of ≥1000 cycles, ensuring reliable release even under complex landing conditions such as grass and snow.

[0048] Example 3: High-voltage line inspection example using cam groove pin coupling + gravity lever reset Technical Solution Details: This embodiment is applicable to environments with strong electromagnetic interference, such as high-voltage line inspection, and focuses on solving the problem of "environmental failure".

[0049] Coupling structure: A cylindrical pin with a diameter of 6mm is set at the top of the state-sensing plunger 20, and a spiral cam groove with a width of 7mm and a lead of 10mm is machined on the end face of the rotary logic cam 30. The pin is embedded in the cam groove. When the plunger pops out, the pin slides along the groove, driving the cam to rotate 35°. The transmission has no meshing backlash and a fast response of ≤0.2s.

[0050] Reset Mechanism: A gravity lever reset mechanism is adopted. A 50mm long and 20g gravity lever is fixed on one side of the cam. After the load is released, the lever drives the cam to reset under the action of gravity, eliminating the need for spring 21 and avoiding the performance degradation of spring 21 at low temperatures.

[0051] Materials and Protection: All core components are made of TC4 titanium alloy, which combines high strength (≥860MPa) with electromagnetic interference resistance. The sealed housing design provides IP67 protection against rain, snow, and dust.

[0052] Electrical safety: The device is connected to the drone via an insulated bracket with an insulation level of ≥10kV, making it suitable for high-voltage line inspection scenarios.

[0053] Applicable scenarios and advantages: Designed specifically for environments with strong electromagnetic interference, the titanium alloy material and sealed structure ensure stable operation in harsh weather and electromagnetic environments. The gravity reset mechanism has no vulnerable parts, has a long maintenance cycle, and is suitable for long-term outdoor inspection tasks.

[0054] Example 4: Miniaturized design + 21-combination spring reset drone logistics small parcel delivery example Technical Solution Details: This embodiment is applicable to urban drone logistics delivery, focusing on addressing the needs of "high-frequency use and lightweight design".

[0055] Coupling structure: It adopts a miniature ratchet structure with a tooth height of 1mm and a tooth pitch of 3mm. The diameter of the rotary logic cam 30 is only 20mm, the diameter of the status sensing plunger 20 is 8mm, the sliding stroke is 15mm, and the cam is driven to rotate 25°. The overall structure is compact with a volume of ≤50mm×30mm×40mm.

[0056] Reset Mechanism: The reset mechanism adopts a combination of torsion spring and tension spring. The torsion spring provides the main reset torque of 0.8 N·m, and the tension spring provides an auxiliary limiting force of 1 N, ensuring that the cam is accurately locked after reset and is suitable for high-frequency use of ≤200 times per day.

[0057] Materials and Lightweight Design: The main load-bearing hook body 10 is made of high-strength engineering plastic PA66 + 30% glass fiber combined with stainless steel inserts, weighing ≤150g and rated load 2kg. The status-sensing plunger 20 slides parallel to the load-bearing plane, facilitating the side-by-side installation of multiple hooks.

[0058] Enhanced safety: The main locking pin 11 is equipped with a secondary locking structure, with a locking gap of ≤0.1mm, to prevent accidental release due to air vibrations.

[0059] Applicable scenarios and advantages: Suitable for drone logistics delivery scenarios. The miniaturized and lightweight design supports multiple hooks to operate simultaneously. The combined spring 21 reset mechanism has high stability and a single release speed of ≤0.5s, which is suitable for the efficient delivery needs of logistics drone platforms such as Meituan and JD.com.

[0060] Working principle: In the initial state, the rotary logic cam 30 is in the first angle position, the reset mechanism torsion spring, tension spring, gravity lever mechanism or combination spring 21 mechanism is in the pre-tightened or initial setting state, the main locking pin 11 is in the locked position to close the hook mouth of the main load-bearing hook body 10, the status sensing plunger 20 is kept in the pop-out position under the pre-pressure of the spring 21, and the trigger linkage 40 is unable to move in the unlocking direction due to the physical restriction of the contour surface of the rotary logic cam 30. When preparing for load lifting, the load lifting ring is attached to the main load-bearing hook 10. The drone starts and lifts upward. The initial tension applied to the load lifting ring is transmitted through the main load-bearing hook 10. On the one hand, the main load-bearing hook 10 is stably supported. On the other hand, the status sensing plunger 20 is driven to overcome the preload of the spring 21 and slide axially from the pop-out position to the pressed-in position. The status sensing plunger 20 is relatively locked to the rotary logic cam 30 through a pawl-ratchet meshing structure, a rack and pin meshing structure, or a cam groove-pin coupling structure. The rotary logic cam 30 is continuously fixed in the first angle position. Its profile surface forms a reliable physical interference with the corresponding part of the trigger link 40, which strictly limits the movement of the trigger link 40 in the unlocking direction. This keeps the main locking pin 11 in the locked state, ensuring that the load will not be accidentally released during aerial lifting, regardless of swaying, wind interference, or light load conditions. When the drone lands with its load, the load contacts the ground, causing the lifting ring to loosen. The tension applied to the main load-bearing hook 10 and the status sensing plunger 20 completely disappears. The preload of the spring 21 quickly drives the status sensing plunger 20 to slide rapidly from the pressed position to the pop-out position along the axial direction. The pop-out stroke of the status sensing plunger 20 is driven by the meshing transmission of the pre-set coupling structure pawl and ratchet, the meshing transmission of the rack and pin, or the sliding transmission of the pin along the spiral cam groove to drive the rotary logic cam 30 to rotate unidirectionally by a preset angle of 25°, 30°, 35° or 45°, realizing the switching from the first angle position to the second angle position. At this time, the profile surface of the rotary logic cam 30 is completely disengaged from the corresponding part of the trigger link 40, providing the trigger link 40 with an effective stroke space to move in the unlocking direction. The main locking pin 11 remains locked, and the device officially enters the armed standby state. Once the pilot confirms that the load has landed smoothly, he controls the drone to pull upwards. The sling is tightened again and a pulling force is applied to the main load-bearing hook 10. This pulling force is efficiently transmitted through the trigger link 40. Since the rotating logic cam 30 is already in the second angle position and no longer restricts the movement of the trigger link 40, the trigger link 40 moves along the preset travel space in the unlocking direction under the action of the pulling force, thereby driving the main locking pin 11 to move from the locked position to the unlocked position. The hook of the main load-bearing hook 10 is fully opened, and the load is stably released. After the load is released, the elastic restoring force of the torsion spring, the tension of the tension spring, the gravity of the gravity lever, or the synergistic force of the combined spring 21 of the reset mechanism are immediately activated, driving the rotary logic cam 30 to accurately reset from the second angle position to the first angle position. In subsequent loading operations, the state sensing plunger 20 can be compressed again by the load tension to the pressed-in position, and the entire device returns to the initial standby state, waiting for the next hoisting and release cycle. Throughout the entire operation, all actions of the state sensing plunger 20, the rotary logic cam 30, the trigger linkage 40, and the reset mechanism do not rely on electronic sensors, electronic controllers, or external power supplies. The state memory and automatic release functions are achieved entirely through the motion coupling of the pure mechanical structure, ensuring reliable operation under various complex working conditions.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A mechanical state memory automatic release hook based on a rotary logic cam, characterized in that, include: The main load-bearing hook body (10) has a movable main locking pin (11) at its hook opening. A state-sensing plunger (20) is slidably disposed along the axial direction and is provided with a spring (21) that gives it an outward tendency to extend. The state-sensing plunger (20) is configured to be compressed to the pressed-in position when subjected to an outward pulling force and to move to the pop-out position under the action of the spring (21) when the pulling force is removed. A rotary logic cam (30) is rotatably mounted about an axis; Triggering link (40) connects the main load-bearing hook body (10) and the main locking pin (11). The state-sensing plunger (20) is coupled to the rotary logic cam (30) such that when the state-sensing plunger (20) moves from the pressed-in position to the ejected position, it drives the rotary logic cam (30) to rotate from the first angle position to the second angle position. When the rotary logic cam (30) is in the first angular position, its structure restricts the movement of the trigger link (40), so that the main locking pin (11) remains locked. When the rotary logic cam (30) is in the second angle position, its structure allows the trigger link (40) to move when the main load-bearing hook (10) is under tension, thereby driving the main locking pin (11) to move and unlock.

2. The mechanical state memory automatic release hook according to claim 1, characterized in that, The state-sensing plunger (20) is coupled to the rotary logic cam (30) through a pawl and ratchet meshing structure. The movement of the state-sensing plunger (20) from the pressed position to the ejected position drives the rotary logic cam (30) to rotate unidirectionally through the meshing structure.

3. The mechanical state memory automatic release hook according to claim 2, characterized in that, The preset angle of rotation of the rotary logic cam (30) is 30 degrees.

4. The mechanical state memory automatic release hook according to claim 1, characterized in that, The profile of the rotary logic cam (30) physically interferes with the corresponding part of the trigger link (40) at the first angular position to restrict its movement in the unlocking direction; at the second angular position, the profile disengages from the corresponding part of the trigger link (40) to provide travel space for its movement in the unlocking direction.

5. The mechanical state memory automatic release hook according to claim 1, characterized in that, It also includes a reset mechanism for driving the rotary logic cam (30) to reset from the second angular position to the first angular position after the main locking pin (11) is unlocked and the load is released.

6. The mechanical state memory automatic release hook according to claim 5, characterized in that, The reset mechanism is one of a torsion spring, a tension spring, or a gravity lever mechanism.

7. The mechanical state memory automatic release hook according to any one of claims 1 to 6, characterized in that, The actions of the state-sensing plunger (20), the rotary logic cam (30), the trigger linkage (40), and the reset mechanism are independent of electronic sensors, electronic controllers, or external power sources.

8. The mechanical state memory automatic release hook according to any one of claims 1 to 6, characterized in that, The axial sliding direction of the state-sensing plunger (20) is perpendicular to the main load-bearing plane of the main load-bearing hook (10).

9. The mechanical state memory automatic release hook according to any one of claims 1 to 6, characterized in that, The main load-bearing hook (10), the status sensing plunger (20), the rotary logic cam (30), and the trigger linkage (40) are made of high-strength stainless steel or aerospace aluminum alloy.

10. The mechanical state memory automatic release hook according to any one of claims 1 to 6, characterized in that, It is used in drone lifting systems as an automatic load release device.

Images