A latch mechanism, locking method and aviation food cart guard rail

Abstract

The present application relates to the technical field of aviation food car, and particularly relates to a latch locking mechanism, a locking method and an aviation food car guardrail, which comprises a detection sensor arranged in a first connecting assembly; a locking execution mechanism arranged in a second connecting assembly and capable of moving relative to the second connecting assembly to enter the first connecting assembly and realize physical locking of the two. The present application converts the traditional mechanical plugging action into quantifiable electronic monitoring signals by arranging the detection sensor in the first connecting assembly and cooperating with the sensing depth design of the locking execution mechanism. Only when the locking execution mechanism really enters the first connecting assembly and reaches the preset sensing depth, the detection sensor can sense the detection surface and output the locking confirmation signal. The false locking problem that the latch has entered the lock hole but is not completely locked in the manual operation of the aviation food car guardrail is fundamentally solved.

Description

Technical Field

[0001] This invention relates to the field of aviation food cart technology, and in particular to a pin locking mechanism, locking method, and aviation food cart guardrail. Background Technology

[0002] During flight and ground transport, the overhead guardrails on airline catering carts are used to secure trays or cargo, preventing them from slipping due to aircraft vibration or tilting. The guardrails are typically locked using a latch mechanism. Most existing latch locking mechanisms employ a simple spring-loaded latch structure.

[0003] Traditional mechanical latches, after being inserted into the locking hole, often rely on tactile feedback for operators to determine if they are properly locked. In the high-frequency use of aviation catering carts, the latch may only partially engage without achieving a true mechanical lock (e.g., the locking ball may not be fully open). In this state, the barrier may appear secure, but during aircraft takeoff and landing or when encountering strong turbulent vibrations, the latch is highly susceptible to detachment, causing the barrier to fail and seriously threatening flight safety. Summary of the Invention

[0004] In this section, as well as in the abstract and title of this application, some simplifications or omissions may be made to avoid obscuring the purpose of this section, the abstract, and the title of this application, and such simplifications or omissions shall not be used to limit the scope of the invention.

[0005] To address the shortcomings of existing technologies, one objective of this invention is to provide a pin locking mechanism.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a pin locking mechanism, including a detection sensor disposed within a first connecting component; and a locking actuator disposed within a second connecting component, capable of moving relative to the second connecting component to enter the first connecting component and achieve physical locking between the two; wherein, when the locking actuator moves relative to the second connecting component to a sensing depth within the first connecting component, the detection sensor senses the detection surface A of the locking actuator and outputs a locking confirmation signal.

[0007] As a preferred embodiment of the pin locking mechanism of the present invention, wherein: in the physically locked state, the axial distance between the detection surface A and the detection sensor is defined as the basic distance L1; the effective detection distance D of the detection sensor satisfies: L1<D≤L1+H; wherein, H is the vertical height of the inclined surface B of the inner cavity of the first connecting assembly in the axial direction.

[0008] As a preferred embodiment of the pin locking mechanism of the present invention, the locking actuator includes an outer shaft and an inner shaft coaxially nested together; the inner shaft has a driving section M1, a reduced diameter section M2, and a tapered transition section M3 connecting the two; the outer shaft has a radial through hole for accommodating a locking member; wherein the locking member is configured as a sphere.

[0009] In a preferred embodiment of the pin locking mechanism of the present invention, a first spring is provided between the outer shaft and the second connecting component, and a second spring is provided between the inner shaft and the outer shaft; the top ends of the outer shaft and the inner shaft are initially flush with each other.

[0010] In a preferred embodiment of the pin locking mechanism of the present invention, the bottom surface of the first connecting component is provided with a maintenance opening, and the detection sensor is detached and connected through the maintenance opening.

[0011] To address the shortcomings of the prior art, another objective of this invention is to provide a locking method for a pin locking mechanism.

[0012] The present invention adopts the following technical solution: a locking method for a pin locking mechanism, comprising the following steps:

[0013] An external driving force compresses the outer shaft, and a locking member, acting as a force transmission medium, compresses the conical transition section M3 of the inner shaft, causing the inner shaft to overcome the resistance of the second spring and move synchronously downward with the outer shaft into the first connecting assembly. When the locking member enters the inner cavity of the first connecting assembly and releases the radial restriction of the second connecting assembly, the second spring drives the inner shaft to move in the opposite direction relative to the outer shaft, and the driving section M1 of the inner shaft forces the locking member out along the radial through hole to achieve physical locking.

[0014] In a preferred embodiment of the locking method of the present invention, the inner shaft moves upward under the action of the second spring, causing its top end to protrude upward from the top surface of the outer shaft.

[0015] In a preferred embodiment of the locking method of the present invention, as the relative displacement between the outer shaft and the inner shaft changes, the detection surface A of the locking actuator enters the effective detection distance D of the detection sensor, and the detection sensor outputs a locking confirmation signal.

[0016] In a preferred embodiment of the locking method of the present invention: the top end of the inner shaft is pressed downward to align the reduced diameter section M2 with the locking member; the first spring drives the outer shaft to reset upward and exit the first connecting assembly, and the inclined surface B of the inner cavity of the first connecting assembly guides the locking member to retract inward.

[0017] To address the shortcomings of existing technologies, another objective of this invention is to provide a guardrail for aircraft food trucks.

[0018] The present invention adopts the following technical solution: an aviation food cart guardrail, including a pin locking mechanism, a lower guardrail, and an upper guardrail rotatably connected to the lower guardrail. A first connecting component is fixedly disposed on the lower guardrail, and a second connecting component is fixedly disposed on the upper guardrail. When the upper guardrail rotates to a locked position perpendicular to or aligned with the lower guardrail, a locking actuator can extend from the second connecting component and lock into the first connecting component to restrict the rotation of the upper guardrail relative to the lower guardrail.

[0019] The beneficial effects of the pin locking mechanism of the present invention are as follows: By setting a detection sensor in the first connecting component and coordinating with the sensing depth design of the locking actuator, the present invention transforms the traditional mechanical insertion and removal action into a quantifiable electronic monitoring signal. Only when the locking actuator truly enters the first connecting component and reaches the preset sensing depth will the detection sensor detect the detection surface and output a locking confirmation signal. This fundamentally solves the problem of false locking, where the pin is inserted into the lock hole but not completely locked, which is prone to occur during manual operation of aviation food truck guardrails, greatly improving the safety and operational efficiency of ground support during air transport. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall locking mechanism of the present invention.

[0022] Figure 2 This is a cross-sectional view of the pin locking mechanism of the present invention.

[0023] Figure 3 This is a schematic diagram of the detection surface of the present invention.

[0024] Figure 4 This is a schematic diagram of the locking actuator of the present invention.

[0025] Figure 5 This is a schematic diagram of the inner shaft structure of the present invention.

[0026] Figure 6 This is a schematic diagram of the structure of the second spring of the present invention.

[0027] Figure 7 This is a schematic diagram of the structure for maintaining the opening in this invention.

[0028] Figure 8 This is a schematic diagram showing the displacement of the locking actuator of the present invention.

[0029] Figure 9 This is a schematic diagram showing the connection between the upper guardrail and the lower guardrail of the present invention.

[0030] In the diagram: 100, first connecting assembly; 101, maintenance opening; 200, detection sensor; 300, second connecting assembly; 400, locking actuator; 401, outer shaft; 401a, radial through hole; 401b, first spring; 402, inner shaft; 402a, second spring; 403, locking element; 500, lower guardrail; 600, upper guardrail; A, detection surface; B, inclined surface; M1, drive section; M2, reduced diameter section; M3, conical transition section. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0032] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0033] Reference Figure 1 and Figure 2 This embodiment provides a pin locking mechanism, including a first connecting component 100, a detection sensor 200, a second connecting component 300, and a locking actuator 400.

[0034] The detection sensor 200 is disposed within the first connecting component 100. The locking actuator 400 is disposed within the second connecting component 300 and is movable relative to the second connecting component 300 to enter the first connecting component 100 and achieve physical locking between the two.

[0035] When the locking actuator 400 moves relative to the second connecting component 300 to the sensing depth within the first connecting component 100, the detection sensor 200 senses the detection surface A of the locking actuator 400 and outputs a locking confirmation signal.

[0036] Specifically, the first connecting assembly 100 serves as a fixed end (such as the lower guardrail of an airline food cart), and its interior forms a cavity for accommodating the locking mechanism. A detection sensor 200 is installed inside the first connecting assembly 100 to monitor the positioning of the locking element in real time. The locking actuator 400 is disposed within the second connecting assembly 300 and is capable of axial movement relative to the second connecting assembly 300.

[0037] When it is necessary to lock the two components, the operator drives the locking actuator 400 to move downward relative to the second connecting component 300. The locking actuator 400 passes through the bottom of the second connecting component 300 and extends into the cavity of the first connecting component 100.

[0038] When the locking actuator 400 descends to the predetermined position, it achieves physical locking with the first connecting component 100 through its internal mechanical structure (such as the opening of the locking element), thereby fixing the first connecting component 100 and the second connecting component 300 into a whole.

[0039] A detection surface A is defined at the end of the locking actuator 400. As the locking actuator 400 moves downward, the detection surface A gradually approaches the detection sensor 200.

[0040] Definition of sensing depth: Sensing depth refers to a specific axial position after the locking actuator 400 enters the inner cavity of the first connecting assembly 100. At this position, the physical locking element has ensured that it has passed the critical point and entered a safe locking state. Only when the detection surface A moves into this sensing depth will the detection sensor 200 detect the presence of the detection surface A and output a locking confirmation signal to the external control system or indicator light.

[0041] Reference Figure 3 In the physically locked state, the axial distance between the detection surface A and the detection sensor 200 is defined as the basic distance L1. The effective detection distance D of the detection sensor 200 satisfies: L1 < D ≤ L1 + H. Wherein, H is the vertical height of the inclined surface B in the axial direction of the inner cavity of the first connecting assembly 100.

[0042] Specifically, this embodiment employs a precise physical modeling of the sensing threshold of the detection sensor 200 to eliminate detection blind spots caused by mechanical tolerances or improper operation. The basic distance L1 is defined as the axial clearance between the detection surface A (such as the bottom end face of the outer shaft 401) and the sensing end face of the detection sensor 200 when the mechanism is in its theoretically locked position. The size of L1 depends on the depth of the mounting bracket inside the first connecting assembly 100 and the installation height of the sensor. The inclined plane height H is defined as the effective projected height of the inclined plane B used to constrain the locking member 403 in the vertical (axial) direction within the cavity of the first connecting assembly 100. H represents the maximum axial floating displacement that the locking member can tolerate before completely disengaging from the lower housing constraint.

[0043] The effective detection distance D of the detection sensor 200 is limited to a specific range, and the effective detection distance D must be greater than the basic distance L1. This ensures that when the locking actuator 400 is fully engaged with the first connecting assembly 100 and reaches the theoretical locking position, the detection surface A is necessarily within the sensor's sensing field of view. If D ≤ L1, even if it is mechanically locked, the sensor cannot detect the detection surface and therefore cannot output a signal.

[0044] By setting the upper limit D≤L1+H, false locking is resolved. In actual use, if the food cart vibrates or the manual operation fails to fully press down, the outer shaft 401 may shift upward from position L1 to a certain extent. As long as the upward displacement of the outer shaft 401 does not exceed H, the locking member 403 remains confined within the coverage area of ​​the inclined plane B. At this time, the locking member 403 cannot retract inward, the mechanism maintains a physical connection, and the guardrail will not detach.

[0045] By limiting D to within L1+H, once the outer shaft 401 floats upwards by a distance exceeding H (i.e., the locking element 403 is about to or has already passed the vertex of the inclined plane B, and the physical locking faces failure), the distance between the detection surface A and the detection sensor 200 will exceed D. At this point, the detection sensor 200 will immediately "lose" the target and stop outputting the locking signal.

[0046] Reference Figure 4 and Figure 5 The locking actuator 400 includes an outer shaft 401 and an inner shaft 402 coaxially nested together. The inner shaft 402 has a drive section M1, a reduced diameter section M2, and a tapered transition section M3 connecting the two. The outer shaft 401 has a radial through hole 401a for accommodating a locking member 403. The locking member 403 is configured as a sphere.

[0047] The inner shaft 402 is slidably disposed within the central cavity of the outer shaft 401, with their center lines coinciding. This nested design not only makes the overall mechanism structure compact and reduces the space occupied within the upper guardrail 600, but also ensures a high degree of consistency in power transmission along the axial direction.

[0048] The outer shaft 401 and the inner shaft 402 can either move downwards synchronously with the external driving force, or they can use the action of the second spring 402a to generate relative axial sliding, thereby triggering the locking logic.

[0049] The inner shaft 402 controls the radial displacement of the locking element 403 by axial changes in its radial dimension. Specifically, it is divided into three functional sections.

[0050] The drive section M1 is located at the bottom and top of the inner shaft 402 and has a large diameter. When the inner shaft 402 is ejected upward to the locking position, the cylindrical surface of the drive section M1 pushes the locking member 403 outward, causing it to partially protrude from the surface of the outer shaft 401, thereby achieving a hard lock with the first connecting assembly 100.

[0051] The reduced diameter section M2 is located at the other end of the inner shaft 402, and its diameter is significantly smaller than that of the drive section M1. When unlocking or initial assembly is required, the reduced diameter section M2 is aligned with the radial through hole 401a, providing inward retraction space for the locking member 403, so that the locking member 403 no longer protrudes from the surface of the outer shaft 401.

[0052] The conical transition section M3 connects the drive section M1 and the reduced-diameter section M2 via an inclined or arc-shaped surface. This section provides smooth radial thrust, guiding the locking element 403 to smoothly switch between "contraction" and "expansion" states during axial movement, thus preventing mechanical dead spots or jamming.

[0053] A radial through hole 401a is provided on the side wall of the outer shaft 401. The function of the radial through hole 401a is to position the locking member 403 circumferentially and axially, ensuring that the locking member 403 can only reciprocate along the radial direction.

[0054] The locking element 403 is a ball, and in this embodiment, a high-strength locking steel ball is used as the locking element. When the ball is subjected to the compression of the inner shaft 402 or the reverse thrust of the inclined surface B of the first connecting assembly 100, the force distribution is uniform, and local wear is not easily generated. When the ball moves within the radial through hole 401a and rubs against the contact surface, rolling friction replaces sliding friction, which greatly reduces the operating resistance and extends the service life of the mechanism.

[0055] Reference Figure 6 A first spring 401b is provided between the outer shaft 401 and the second connecting assembly 300, and a second spring 402a is provided between the inner shaft 402 and the outer shaft 401.

[0056] In this embodiment, a two-degree-of-freedom dynamic feedback system is constructed by nesting the first spring 401b and the second spring 402a, enabling the mechanism to automatically switch actions according to the physical space it is in.

[0057] Specifically, the first spring is installed between the outer shaft 401 and the support structure of the second connecting assembly 300. Its main function is to provide an upward reset preload for the entire locking actuator. During the unlocking process, once the physical limit is released, the first spring 401b will drive the outer shaft 401 to move upward as a whole, exiting the first connecting assembly 100, so that the guardrail returns to a freely rotatable state.

[0058] The second spring is installed between the inner shaft 402 and the outer shaft 401. Its core function is to drive the inner shaft 402 to generate relative displacement with respect to the outer shaft 401. After entering the first connecting assembly 100, at the moment when the locking member 403 releases its radial restriction, it is the elastic force of the second spring 402a that drives the inner shaft 402 to pop upward, pushing the driving section M1 towards the locking member 403, thereby completing the automatic locking action.

[0059] The top ends of the outer shaft 401 and the inner shaft 402 are initially in a plane-aligned state.

[0060] Specifically, in the top design of the outer shaft 401 and the inner shaft 402, this invention intentionally sets their tops to be flush with each other in the initial, unpressurized state. This flush design ensures a smooth surface with no protruding parts in the initial state, effectively preventing the latch from accidentally extending due to snagging on foreign objects when the catering cart moves within a confined space. Simultaneously, it clearly defines the starting point for the operator: in the initial state, applying downward pressure to this plane is sufficient to initiate the locking process.

[0061] When an external driving force, such as a finger or pressure plate, presses the outer shaft 401 downwards, the outer shaft 401 moves downwards first. At this time, since the inner shaft 402 is supported on the outer shaft 401 by the second spring 402a, and the conical transition section M3 of the inner shaft 402 abuts against the locking member 403, the power is transmitted from the locking member 403 to the inner shaft 402, realizing the synchronous downward movement of the two shafts.

[0062] Reference Figure 7 The bottom surface of the first connecting component 100 is provided with a maintenance opening 101, through which the detection sensor 200 is detached and connected.

[0063] Specifically, the maintenance opening 101 is located at the bottom of the inner cavity of the first connecting assembly 100, and its axis is basically coincident with the motion axis of the locking actuator 400.

[0064] The detection sensor 200 is detachably connected to the first connection assembly 100 through the maintenance opening 101. In specific implementations, this can be achieved in various ways.

[0065] The housing of the detection sensor 200 may be provided with external threads, and can be secured by internal threads at the maintenance opening 101 or by a mating nut assembly. This method facilitates precise adjustment of the axial distance between the sensing end face and the detection surface A of the detection sensor 200.

[0066] The detection sensor 200 is mounted on a separate mounting plate or bracket, which is fastened to the edge of the maintenance opening 101 by screws.

[0067] The probe sensor 200 is positioned at the maintenance opening 101 using a flexible fastener, enabling quick insertion and removal.

[0068] During the use of the aircraft catering truck guardrails, if the detection sensor 200 experiences an electrical fault, sensitivity degradation, or requires cleaning of the sensing end face, maintenance personnel only need to operate from the bottom of the first connecting assembly 100. There is no need to disassemble the mechanical connection between the upper and lower guardrails, nor to disassemble the complex locking actuator 400.

[0069] The presence of the maintenance opening 101 allows maintenance personnel to observe the real-time output signal of the detection sensor 200 while fine-tuning its installation depth at the bottom, thereby ensuring that the sensing distance D meets the precise requirement of L1<D≤L1+H.

[0070] Reference Figure 8 This embodiment provides a locking method for a pin locking mechanism, including the following steps:

[0071] An external driving force compresses the outer shaft 401, and the locking member 403, acting as a force transmission medium, compresses the conical transition section M3 of the inner shaft 402. This causes the inner shaft 402 to overcome the resistance of the second spring 402a and move synchronously downwards with the outer shaft 401 into the first connecting assembly 100. When the locking member 403 enters the inner cavity of the first connecting assembly 100 and releases the radial restriction of the second connecting assembly 300, the second spring 402a drives the inner shaft 402 to move in the opposite direction relative to the outer shaft 401. The driving section M1 of the inner shaft 402 then extrudes the locking member 403 along the radial through hole 401a, thus achieving physical locking.

[0072] Specifically, when an external driving force (such as manual pressing or actuator thrust) is applied to the top of the outer shaft 401, the outer shaft 401 begins to move downward relative to the second connecting assembly 300. At this time, the locking member 403 (ball) is confined within the narrow-diameter inner wall of the second connecting assembly 300 and cannot move radially outward. In this radially restricted state, the locking member 403 acts as a force transmission medium for axial force. The outer shaft 401 drives the locking member 403 downward through the radial through-hole 401a, while the inner surface of the locking member 403 abuts against the conical transition section M3 of the inner shaft 402. Due to the presence of the conical surface, the downward pressure of the outer shaft 401 is transmitted to the inner shaft 402 through the component force of the ball, forcing the inner shaft 402 to overcome the resistance of the second spring 402a below it and move downward synchronously with the outer shaft 401 at a speed basically consistent with that of the outer shaft 401. This process ensures that the internal relative positions of the mechanism do not become disordered before entering the lock hole.

[0073] As the synchronous downward movement continues, when the outer shaft 401 drives the locking member 403 to move into the inner cavity region of the first connecting component 100, the locking member 403 is freed from the rigid constraint of the inner wall of the second connecting component 300. At this time, the wide-diameter inner cavity of the first connecting component 100 provides the locking member 403 with physical space for outward expansion, and the original axial force transmission balance is broken.

[0074] The inner shaft 402, having lost the axial support of the ball, moves rapidly upward (in the opposite direction) relative to the outer shaft 401 under the restoring force of the compressed second spring 402a. During the rebound of the inner shaft 402, its large-diameter drive segment M1 slides past the inner side of the locking member 403. Due to the forceful compression of the drive segment M1, the locking member 403 is pushed outward along the radial through hole 401a, causing part of its structure to protrude from the outer surface of the outer shaft 401 and embed into the locking groove or below the inclined surface B of the first connecting assembly 100. At this time, the drive segment M1 of the inner shaft acts like a pin, locking the ball from the inside and preventing it from retracting. Since the ball spans between the outer shaft 401 and the first connecting assembly 100, a rigid axial lock is achieved between the first connecting assembly 100 and the second connecting assembly 300.

[0075] The inner shaft 402 moves upward under the action of the second spring 402a, causing its top end to protrude upward from the top surface of the outer shaft 401.

[0076] Specifically, when the locking action reaches the critical point (i.e., the locking element 403 enters the widened inner cavity of the first connecting assembly 100), the second spring 402a, which was originally in a compressed state, instantly releases energy. Since the outer shaft 401 is maintained by the limiting or operating force of the first connecting assembly 100, its position remains relatively stable; the second spring 402a then drives the inner shaft 402 to slide rapidly upward relative to the outer shaft 401. This movement directly breaks the initial planar balance between the tops of the inner shaft 402 and the outer shaft 401. The top of the inner shaft 402 passes through the top opening of the outer shaft 401, ultimately forming a significant upward convex height difference.

[0077] As the relative displacement between the outer shaft 401 and the inner shaft 402 changes, the detection surface A of the locking actuator 400 enters the effective detection distance D of the detection sensor 200, and the detection sensor 200 outputs a locking confirmation signal.

[0078] The downward pressure on the protruding tip of the inner shaft 402 aligns the reduced diameter section M2 with the locking member 403. The first spring 401b drives the outer shaft 401 to return upward and exit the first connecting assembly 100, and the locking member 403 is guided inward by the inclined surface B of the inner cavity of the first connecting assembly 100.

[0079] Specifically, in the physically locked state, since the inner shaft 402 is in a protruding state, the operator pushes down the protruding tip of the inner shaft 402, causing it to move downwards against the resistance of the second spring 402a. As the inner shaft 402 moves downwards, its smaller diameter reduced-diameter section M2 moves back to a position opposite to the radial through-hole 401a of the outer shaft 401. At this time, the inner side of the ball of the locking member 403 loses the rigid support of the large-diameter driving section M1, providing physical space for the locking member 403 to retract inwards.

[0080] When the inner shaft 402 is pressed to a predetermined depth and the locking member 403 unlocks, the previously compressed first spring 401b, storing significant elastic potential energy, begins to drive the outer shaft 401 upwards, preparing to exit the first connecting assembly 100. During the upward movement of the outer shaft 401, the locking member 403 contacts the inclined surface B at the top of the inner cavity of the first connecting assembly 100. Due to the radial constraint force of the inclined surface B, the locking member 403 is pushed inwards and fully enters the reduced-diameter section M2 of the inner shaft. After the locking member 403 retracts, the overall outer diameter of the locking actuator 400 is again smaller than the limiting apertures of the second connecting assembly 300 and the first connecting assembly 100. Under the continuous drive of the first spring 401b, the outer shaft 401 and inner shaft 402 spring upwards synchronously until they return to their initial flush-plane state. At this point, the physical lock between the upper and lower guardrails is released, and the upper guardrail can rotate freely.

[0081] Reference Figure 9 This embodiment provides an aviation food cart guardrail, including a pin locking mechanism, a lower guardrail 500, and an upper guardrail 600 rotatably connected to the lower guardrail 500. A first connecting component 100 is fixedly disposed on the lower guardrail 500, and a second connecting component 300 is fixedly disposed on the upper guardrail 600.

[0082] When the upper guardrail 600 rotates to a locked position that is perpendicular to or aligned with the lower guardrail 500, the locking actuator 400 can extend from the second connecting component 300 and lock into the first connecting component 100 to restrict the rotation of the upper guardrail 600 relative to the lower guardrail 500.

[0083] Specifically, the lower guardrail 500 serves as a fixed base and is typically welded or fixed to the vehicle body structure on the top of the food truck. The first connecting component 100 of the present invention is fixedly installed at a specific locking point on the lower guardrail 500.

[0084] The upper guardrail 600 is rotatably connected to the lower guardrail 500 via a pivot or hinge mechanism, allowing it to be switched between "folded or open" or "different angles" according to operational needs. The second connecting component 300 of the present invention is fixedly installed at the corresponding position of the upper guardrail 600.

[0085] A detection sensor 200 installed inside the lower guardrail 500 captures the locking signal in real time. This signal is fed back to the main control system of the food truck via a wiring harness (or wireless module) installed inside the lower guardrail 500. If the upper guardrail is not rotated into place, or the latch is not properly locked, the detection sensor 200 will not be able to detect the detection surface A, and the system will notify ground staff through warning lights or voice prompts. This solves the safety hazards caused by relying solely on manual visual inspection of whether the guardrail is locked, ensuring that the guardrail remains in a stable locked state throughout the flight.

[0086] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A pin locking mechanism, characterized in that: include, A detection sensor (200) is disposed within the first connection assembly (100); A locking actuator (400) is disposed within the second connecting component (300) and is movable relative to the second connecting component (300) to enter the first connecting component (100) and achieve physical locking between the two. When the locking actuator (400) moves relative to the second connecting component (300) to the sensing depth within the first connecting component (100), the detection sensor (200) senses the detection surface A of the locking actuator (400) and outputs a locking confirmation signal; In the physically locked state, the axial distance between the detection surface A and the detection sensor (200) is defined as the basic distance L1; The effective detection distance D of the detection sensor (200) satisfies: L1<D≤L1+H; Wherein, H is the vertical height of the inclined surface B of the inner cavity of the first connecting component (100) in the axial direction; The locking actuator (400) includes an outer shaft (401) and an inner shaft (402) that are coaxially nested. The inner shaft (402) has a drive section M1, a reduced diameter section M2, and a tapered transition section M3 connecting the two. The outer shaft (401) has a radial through hole (401a) for accommodating a locking element (403). The locking element (403) is configured as a sphere; A first spring (401b) is provided between the outer shaft (401) and the second connecting assembly (300), and a second spring (402a) is provided between the inner shaft (402) and the outer shaft (401). The top ends of the outer shaft (401) and the inner shaft (402) are initially in a plane-aligned state.

2. The pin locking mechanism as described in claim 1, characterized in that: The bottom surface of the first connecting component (100) is provided with a maintenance opening (101), through which the detection sensor (200) is detached and connected.

3. A locking method for a pin locking mechanism, characterized in that: Applied to the pin locking mechanism as described in claim 1 or 2, the locking method of the pin locking mechanism includes the following steps: External driving force squeezes the outer shaft (401), and the locking member (403) is used as the force transmission medium to squeeze the conical transition section M3 of the inner shaft (402), which drives the inner shaft (402) to overcome the resistance of the second spring (402a) and move down synchronously with the outer shaft (401) into the first connecting assembly (100). When the locking member (403) enters the inner cavity of the first connecting assembly (100) and releases the radial restriction of the second connecting assembly (300), the second spring (402a) drives the inner shaft (402) to move in the opposite direction relative to the outer shaft (401), and the driving segment M1 of the inner shaft (402) pushes the locking member (403) out along the radial through hole (401a) to achieve physical locking.

4. The locking method as described in claim 3, characterized in that: The inner shaft (402) moves upward under the action of the second spring (402a), causing its top end to protrude upward from the top surface of the outer shaft (401).

5. The locking method as described in claim 4, characterized in that: As the relative displacement between the outer shaft (401) and the inner shaft (402) changes, the detection surface A of the locking actuator (400) enters the effective detection distance D of the detection sensor (200), and the detection sensor (200) outputs a locking confirmation signal.

6. The locking method as described in claim 4 or 5, characterized in that: Press down on the protruding top of the inner shaft (402) to align the reduced diameter section M2 with the locking member (403). The first spring (401b) drives the outer shaft (401) to reset upward and exit the first connecting assembly (100), and the locking member (403) is guided inward by the inclined surface B of the inner cavity of the first connecting assembly (100).

7. A protective railing for an aviation food cart, characterized in that: The device includes the pin locking mechanism as described in claim 1 or 2, and also includes a lower guardrail (500) and an upper guardrail (600) rotatably connected to the lower guardrail (500), wherein a first connecting component (100) is fixedly disposed on the lower guardrail (500) and a second connecting component (300) is fixedly disposed on the upper guardrail (600); When the upper guardrail (600) is rotated to a locked position that is perpendicular to or aligned with the lower guardrail (500), the locking actuator (400) can extend from the second connecting component (300) and lock into the first connecting component (100) to restrict the rotation of the upper guardrail (600) relative to the lower guardrail (500).

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