Airplane cabin door anti-sinking mechanism
By combining a suspension hinge, guide block, lower locking hook, upper locking hook, and step-by-step cam, the operation of the aircraft cabin door is simplified, the problems of cabin door space occupation and locking complexity are solved, and safe and reliable locking and stability are achieved.
Patent Information
- Application Number
- CN202511943513.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-22
- Publication Date
- 2026-02-24
AI Technical Summary
In existing aircraft door designs, the observation window occupies a large space, the door is inconvenient to operate and the anti-sinking mechanism is complex, the single-point locking has insufficient load-bearing capacity, and the two-point locking mechanism has complex movement.
The anti-sinking mechanism, consisting of a suspension hinge, guide block, lower locking hook, upper locking hook, step-by-step cam, and handle shaft, simplifies the motion mechanism through a triangular stable connection, achieving safe and reliable locking.
The hatch operation has been simplified, locking security and load-bearing capacity have been improved, hatch sinking has been prevented, and the convenience and stability of operation have been enhanced.
Smart Images
Figure CN121553352A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of aircraft structural design technology, and specifically relates to an anti-sinking mechanism for aircraft cabin doors. Background Technology
[0002] For obstructive hatches with observation windows of the same size as the passenger cabin observation windows, which open outwards and upwards, the space occupied by the large observation windows limits the usable space of the hatch mechanism. The typical design is as follows:
[0003] 1. The door latch and operating handle are located above the observation window. The handle is far from the cabin floor and the ground, making operation inconvenient. The handle directly drives the latch, and accidental contact with the handle may lead to the door being accidentally unlocked and opened, causing danger.
[0004] 2. When the hatch is opened, after the latch release and lifting motion is completed, the anti-sinking mechanism usually adopts a single-point locking or two-point locking method. Among them: the single-point locking anti-sinking mechanism is simple, but due to the limitation of the arrangement of other mechanisms on the hatch, the installation position is located on one side of the hatch, and the load-bearing condition is not good; in the two-point locking anti-sinking mechanism, the two locking points are symmetrically arranged with respect to the hatch, and in order to restrict the degree of freedom of rotation around the line connecting the two points, a more complex motion mechanism is required to realize its function. Summary of the Invention
[0005] To address the aforementioned issues, this application provides an aircraft door anti-sinking mechanism, which mainly includes a suspension hinge, a guide block, a lower locking hook, an upper locking hook, a step-by-step cam, a handle shaft, and a door latch.
[0006] One end of the suspension hinge is hinged to the door frame above the hatch, and the other end is equipped with a locking pin and a hinge roller; the guide block is fixed to the upper part of the hatch and has a guide groove extending in the vertical direction to accommodate the hinge roller of the suspension hinge.
[0007] The hatch latch has a latch crank with rollers at both ends. The rollers of the latch cranks mesh with the lifting drive limiting surface of the latch groove fixedly installed on the door frame. The hatch latch has a latch fork-shaped arm in the middle. The handle shaft is hinged to the lower middle part of the hatch. A handle that drives the handle shaft to rotate and a latch lever that rotates with the handle shaft are connected to it. The latch lever can move in and out of the latch fork-shaped arm of the hatch latch during rotation. The latch lever is also hinged to a step-by-step cam through a lower connecting rod.
[0008] The step-by-step cam has a cam surface adapted to accommodate a single-ear roller of a roller crank. The cam surface includes a first surface and a second surface. The first surface is configured concentrically with the step-by-step cam axis so that when the step-by-step cam initially rotates, the single-ear roller of the roller crank is not subjected to force within the cam surface. The second surface is located after the first surface and has a trajectory away from the step-by-step cam axis so that when the step-by-step cam subsequently rotates, the single-ear roller of the roller crank is subjected to force within the cam surface to drive the roller crank. The roller crank is hinged to a locking rocker arm via a connecting rod. The locking rocker arm is hinged to an upper locking hook via a push rod. The upper locking hook is located above the locking pin of the suspension hinge, and the lower locking hook is fixed to the hatch and located below the locking pin.
[0009] 2. The aircraft door anti-sinking mechanism as described in claim 1, wherein the suspension hinge is hinged to the door frame via the upper suspension lug.
[0010] 3. The aircraft door anti-sinking mechanism as described in claim 1, wherein the guide block is fixedly installed on the door by means of a mounting base plate.
[0011] 4. The aircraft door anti-sinking mechanism as described in claim 1, wherein the lower part of the lower connecting rod is hinged to the double lugs of the latch lever, and the upper part is hinged to the double lug joint of the step-by-step cam.
[0012] 5. The aircraft cabin door anti-sinking mechanism as described in claim 1, characterized in that the roller crank is hinged to the middle lug of the transition rocker arm via a central connecting rod, one end of the transition rocker arm is hinged to the cabin door, the other end of the transition rocker arm is hinged to the rocker arm via an upper connecting rod, and the rocker arm is connected to the locking rocker arm via a rotating shaft.
[0013] 6. The aircraft door anti-sinking mechanism as described in claim 1, characterized in that the anti-sinking mechanism forms three strokes by pulling a handle:
[0014] In the first stroke, the handle is initially in the closed position, the roller of the latch crank is in the slot of the lifting drive limiting surface of the latch groove, the hatch is completely closed, and neither the lower nor upper locking hook is in contact with the locking pin. Pull the handle outward and upward, the latch lever of the handle shaft moves to engage with the slot of the latch fork arm, and drives the lower connecting rod to move downward, driving the step cam to rotate; during this stroke, the roller of the single ear of the roller crank slides in the first curved surface, and the roller crank remains stationary;
[0015] Stroke 2: Continue to pull the handle outward and upward. The latch lever of the handle shaft presses against the slot of the latch fork arm, driving the hatch latch to rotate around the latch shaft. Under the reaction force of the latch slot, the hatch moves upward. As the hatch moves upward, the hinge roller of the suspension hinge moves to the bottom of the guide slot of the guide block; the lower locking hook moves upward synchronously and engages with the locking pin of the suspension hinge. The step cam continues to rotate. The cam surface of the step cam is concentric with the step cam shaft. The roller of the single ear of the roller crank continues to slide in the first curved surface, while the roller crank remains stationary.
[0016] Stroke 3: Continue to pull the handle outward and upward. The stepping cam continues to rotate. The roller on the single lug of the roller crank slides in the second curved surface of the stepping cam. The roller crank rotates, driving the upper locking hook downward through the connecting rod, engaging with the locking pin of the suspension hinge. At this time, the lower locking hook and the upper locking hook together hold the locking pin. Simultaneously, the hinge roller engages with the guide groove, jointly locking the hatch and the suspension hinge. Push the hatch outward and upward, and the hatch rotates around the pivot of the suspension hinge.
[0017] The anti-sinking mechanism provided in this application utilizes the stability characteristics of a triangle, has a simple motion mechanism, secure and reliable locking, and good force distribution. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structural installation of a preferred embodiment of the aircraft cabin door anti-sinking mechanism of this application.
[0019] Figure 2 This application Figure 1 A schematic diagram of the structural composition of the embodiment shown.
[0020] Figure 3 This is a schematic diagram of a suspended hinge structure.
[0021] Figure 4 This is a schematic diagram of a roller crank structure.
[0022] Figure 5 This is a schematic diagram of a step-by-step cam structure.
[0023] Figure 6 This is a schematic diagram of the latch groove structure.
[0024] Figure 7 This is a schematic diagram of the hatch latch structure.
[0025] Figure 8 This is a schematic diagram of the guide block structure.
[0026] Figure 9 This is a schematic diagram of the locking rocker arm structure.
[0027] Figure 10 This is a schematic diagram of the push rod structure.
[0028] Figure 11 This is a schematic diagram of the locking hook structure.
[0029] Figure 12a This is a diagram showing the hatch in the closed position.
[0030] Figure 12b This is a schematic diagram showing the end of the anti-sinking mechanism's stroke.
[0031] Figure 12c This is a schematic diagram showing the end of the second stroke of the anti-sinking mechanism.
[0032] Figure 12d This is a schematic diagram showing the end of the third stroke of the anti-sinking mechanism.
[0033] Figure 13 This is a diagram illustrating the hatch opening process.
[0034] Among them, 1-door frame, 2-hatch door, 3-suspension hinge, 31-suspension lug, 32-locking pin, 33-hinge roller, 4-guide block, 41-mounting base plate, 42-guide groove, 5-lower locking hook, 6-upper locking hook, 7-push rod, 8-locking rocker arm, 9-rotating shaft, 10-rocker arm, 11-upper connecting rod, 12-adapter rocker arm, 13-middle connecting rod, 14-roller crank, 141-crank double lug, 142-single lug, 15-stepping cam, 151-double lug connector, 152-cam surface, 16-lower connecting rod, 17-latch lever, 18-handle shaft, 19-handle, 20-hatch door latch, 201-latch crank, 202-latch shaft, 203-latch fork arm, 21-latch groove, 211-lifting drive limit surface. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0036] This application provides an aircraft cabin door anti-sinking mechanism, such as... Figures 1-13 As shown, it mainly includes a suspension hinge 3, a guide block 4, a lower locking hook 5, an upper locking hook 6, a step-by-step cam 15, a handle shaft 18, and a hatch latch 20;
[0037] One end of the suspension hinge 3 is hinged to the door frame 1 above the hatch 2, and the other end is provided with a locking pin 32 and a hinge roller 33; the guide block 4 is fixed to the upper part of the hatch 2 and has a guide groove 42 extending in the vertical direction for accommodating the hinge roller 33 of the suspension hinge 3.
[0038] The hatch latch 20 has a latch crank 201 with rollers at both ends. The rollers of the latch crank 201 engage with the lifting drive limiting surface 211 of the latch groove 21 fixedly installed on the door frame 1. The hatch latch 20 has a latch fork-shaped arm 203 in the middle. The handle shaft 18 is hinged to the lower middle part of the hatch 2. A handle 19 that drives the handle shaft 18 to rotate and a latch lever 17 that rotates with the handle shaft 18 are connected to it. The latch lever 17 can move in and out of the latch fork-shaped arm 203 of the hatch latch 20 during rotation. The latch lever 17 is also hinged to the step cam 15 through the lower connecting rod 16.
[0039] The step-by-step cam 15 has a cam surface 152 adapted to accommodate the roller of the single ear 142 of the roller crank 14. The cam surface 152 includes a first surface and a second surface. The first surface is configured to be concentric with the axis of rotation of the step-by-step cam 15 so that when the step-by-step cam 15 initially rotates, the roller of the single ear 142 of the roller crank 14 is not subjected to force within the cam surface 152. The second surface is located after the first surface and has a trajectory away from the axis of rotation of the step-by-step cam 15 so that when the step-by-step cam 15 subsequently rotates, the roller of the single ear 142 of the roller crank 14 is subjected to force within the cam surface 152 to drive the roller crank to move. The roller crank 14 is hinged to the locking rocker arm 8 by a connecting rod. The locking rocker arm 8 is hinged to the upper locking hook 6 by a push rod 7. The upper locking hook 6 is located above the locking pin 32 of the suspension hinge 3. The lower locking hook 5 is fixed on the hatch 2 and is located below the locking pin 32.
[0040] refer to Figure 1 Figure 2 In the initial state of the hatch 2, the suspension hinge 3 is hinged to the door frame via the guide block 4. Therefore, the hatch 1 has two points of movement: one is the hinge between the suspension hinge 3 and the door frame, and the other is the hinge between the hatch 2 and the suspension hinge 3. One of the purposes of this application is to eliminate the second hinge point when the hatch 2 is opened, so that the hatch 2 and the suspension hinge 3 form a whole, preventing the hatch from deflecting at the hinge point and causing the hatch to swing and sink.
[0041] Specifically, this application designs new movable connection points, namely the lower locking hook 5 and the upper locking hook 6 on the hatch. These two hooks lock the locking pin 32 of the suspension hinge 3 before the hatch is opened. Thus, the locking point, together with the two hinge points of the original hatch 2 and the suspension hinge 3, forms a triangular connection, ensuring a stable connection between the hatch 2 and the suspension hinge 3.
[0042] refer to Figure 1 , Figure 2 and Figure 12a The suspension hinge 3 includes a suspension lug 31, a locking pin 32, and a hinge roller 33. The suspension hinge 3 is hinged to the upper part of the door frame structure 1 through the suspension lug 31. The two hinge rollers 33 are respectively embedded in the guide grooves 42 of the two guide blocks 4 fixedly installed on the hatch 2.
[0043] refer to Figure 1 , Figure 2 and Figure 8 The guide block 4 includes a mounting base plate 41 and a guide groove 42. Two guide blocks 4 are fixedly installed on the upper part of the hatch 2 through the mounting base plate 41, and the guide grooves 42 are arranged facing each other.
[0044] The above describes the connection structure between the hatch 2 and the suspension hinge 3, as well as the connection structure between the suspension hinge 3 and the door frame.
[0045] Based on this, this application provides a new hatch latch structure, such as Figure 7 As shown, the hatch latch 20 includes a latch crank 201 with rollers, a latch shaft 202, and a latch fork arm 203. The hatch latch 20 is hinged to the lower middle part of the hatch 2 via the latch shaft 202. The rollers of the two latch cranks 201 with rollers respectively engage with the lifting drive limiting surfaces 211 of the two latch slots 21 fixedly installed on the door frame structure 1, as shown. Figure 6 As shown, two latch slots 21 are respectively fixedly installed on both sides of the lower middle part of the door frame structure 1, as... Figure 1 and Figure 13 As shown.
[0046] Next, the drive mechanism handle shaft 18 of this application is hinged to the lower middle part of the hatch 2. The latch lever 17 and handle 19 are fixedly connected to the handle shaft 18. The latch lever 17 is used to deflect downwards to drive the hatch latch 20, thereby driving the hatch 2 to move. Simultaneously, the latch lever 17 also pulls the upper linkage mechanism, driving the upper structural components to operate, as will be described in detail later. The handle 19 is a component used to drive the handle shaft 18 to rotate, such as... Figure 2 As shown.
[0047] Linkage mechanisms such as Figure 2 As shown, it includes a push rod 7, a locking rocker arm 8, a rotating shaft 9, a rocker arm 10, an upper connecting rod 11, a transition rocker arm 12, a middle connecting rod 13, and a roller crank 14. Figure 4 As shown, the roller crank 14 includes two crank lugs 141 and a single lug 142 with a roller; as Figure 5 As shown, the step-by-step cam 15 includes a double-ear joint 151 and a cam surface 152; the roller of the single-ear joint 142 with rollers is embedded in the cam groove of the cam surface 152. The roller crank 14 and the step-by-step cam 15 are respectively hinged to the hatch 2.
[0048] like Figure 2As shown, the lower part of the lower connecting rod 16 is hinged to the double lugs of the latch lever 17, and the upper part is hinged to the double lug joint 151 of the step cam 15. The transition rocker arm 12 is hinged to the hatch 2. The lower part of the middle connecting rod 13 is hinged to the crank double lugs 141 of the roller crank 14, and the upper part is hinged to the middle lug of the transition rocker arm 12.
[0049] like Figure 2 , Figure 9 , Figure 10 and Figure 11 As shown, the rotating shaft 9 is hinged to the upper part of the hatch 2, the locking hook rocker arm 8 and rocker arm 10 are fixedly connected to the rotating shaft 9, and the upper locking hook 6 is hinged to the upper part of the hatch 2; the left end of the push rod 7 is hinged to the double ears of the locking hook rocker arm 8, and the right end is hinged to the upper single ear of the upper locking hook 6; the lower part of the upper connecting rod 11 is hinged to the far end ear of the transition rocker arm 12, and the upper part is hinged to the rocker arm 10; the lower part of the lower connecting rod 16 is hinged to the double ears of the latch lever 17, and the upper part is hinged to the double ear joint 151 of the stepping cam 15.
[0050] Based on the above structure, in some optional embodiments, the anti-sinking mechanism forms three strokes by pulling the handle 19:
[0051] In the first stroke, the handle 19 is initially in the closed position, the roller of the latch crank 201 is in the groove of the lifting drive limiting surface 211 of the latch groove 21, the hatch is completely closed, and neither the lower locking hook 5 nor the upper locking hook 6 is in contact with the locking pin 32. The handle 19 is pulled outward and upward, and the latch lever 17 of the handle shaft 18 moves to engage with the groove of the latch fork arm 203, and drives the lower connecting rod 16 to move downward, driving the stepping cam 15 to rotate. During this stroke, the roller of the single ear 142 of the roller crank 14 slides in the first curved surface, and the roller crank 14 remains stationary.
[0052] like Figure 12a As shown, when the hatch is in the closed state, the hatch 2 is located in the door frame structure 1, and its shape is flush with the door frame structure 1; the handle 19 is in the closed position, and its shape is flush with the door 2; the roller of the latch crank 201 with rollers of the hatch latch 20 is in the groove of the lifting drive limiting surface 211 of the latch groove 21, which keeps the hatch latch in the fully closed position; the lower locking hook 5 and the upper locking hook 6 are disengaged from the suspension hinge 3, that is, the locking pin 32 is not locked, and the hatch 2 and the suspension hinge 3 are only connected by the guide block 4, and the hinge roller 33 is located above the guide groove 42 of the guide block 4.
[0053] Then pull handle 19 outwards and upwards. Figures 12a-12bAs can be seen, the handle shaft 18 rotates clockwise solely to move the latch lever 17 into the slot of the latch fork arm 203. During this process, and during the formation of the second process, although the rotation of the handle shaft 18 causes the lower connecting rod 16 to move downwards, the presence of the stepping cam 15 prevents the vertical movement of the lower connecting rod 15 from being transmitted to the upper middle connecting rod. (Refer to...) Figure 4 , Figure 5 and Figure 12b The front part of the cam surface 152 of the step-by-step cam 15 is a circular segment centered on its axis. When the step-by-step cam 15 rotates, it does not exert force on the roller of the single ear 142 within the cam surface 152; it only changes the positional relationship between the two. When the roller of the single ear 142 rotates to... Figure 12c When the step cam 15 is positioned within the cam surface 152 shown, the continued rotation of the step cam 15 will drive the single ear 142 to move.
[0054] In the second stroke, continue to pull the handle 19 outward and upward. The latch lever 17 of the handle shaft 18 presses against the slot of the latch fork arm 203, driving the hatch latch 20 to rotate around the latch shaft 202. Under the reaction force of the latch groove 21, the hatch 2 moves upward. As the hatch 1 moves upward, the hinge roller 33 of the suspension hinge 3 moves to the bottom of the guide groove 42 of the guide block 4. The lower locking hook 5 moves upward synchronously and engages with the locking pin 32 of the suspension hinge 3. The step cam 15 continues to rotate. The cam surface 152 of the step cam 15 is concentric with the axis of rotation of the step cam 15. The roller of the single ear 142 of the roller crank 14 continues to slide in the first curved surface. The roller crank 14 remains stationary.
[0055] refer to Figures 12b-12c The primary purpose of this movement is to lift the hatch. Understandably, the latch lever 17 of the handle shaft 18 pressing against the slot of the latch fork arm 203 causes rotation around the latch shaft 202, which is hinged to the hatch 2. This rotation of the latch shaft 202 causes movement of the latch shaft 202, with the roller of the latch crank 201 as a fulcrum. Figure 7 It can be seen that it can move forward and backward, and also move upward. This movement will drive the entire hatch to move upward. At this time, the lower locking hook 5 located above the hatch moves upward synchronously and engages with the locking pin 32 of the suspension hinge 3, that is, hooks the lower half of the locking pin 32.
[0056] Stroke 3: Continue to pull the handle 19 outward and upward. The stepping cam 15 continues to rotate. The roller of the single ear 142 of the roller crank 14 slides in the second curved surface of the stepping cam 15. The roller crank 14 rotates and drives the upper locking hook 6 to move downward through the connecting rod, engaging with the locking pin 32 of the suspension hinge 3. At this time, the lower locking hook 5 and the upper locking hook 6 jointly hold the locking pin 32. At the same time, the hinge roller 33 engages with the guide groove 42, jointly locking the hatch 2 and the suspension hinge 3. Push the hatch 2 outward and upward, and the hatch 2 rotates around the pivot of the suspension hinge 3.
[0057] like Figures 12c-12d As shown, the movement of this part mainly drives the upper locking hook 6 to deflect downwards and hook the upper part of the locking pin 32. Specifically, the roller of the single ear 142 of the roller crank 14 slides in the second curved surface of the step cam 15, pushing the middle connecting rod 13 to move upwards, the connecting rocker arm 12 to rotate, the upper connecting rod 11 to move upwards, the locking hook rocker arm 8, the rotating shaft 9, and the rocker arm 10 to rotate, and the push rod 7 to move to the right, pushing the upper locking hook 6 to rotate and engage with the locking pin 32 of the suspension hinge 3.
[0058] Finally, as Figure 13 As shown, once the hatch is raised to the position and locked by the lower locking hook 5, upper locking hook 6, and locking pin 32, the hatch can be opened outward and upward by pushing it outward and upward around the suspension lug 31 of the suspension hinge 3.
[0059] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. An anti-sinking mechanism for aircraft cabin doors, characterized in that, Includes suspension hinge (3), guide block (4), lower locking hook (5), upper locking hook (6), step cam (15), handle shaft (18), and hatch latch (20); One end of the suspension hinge (3) is hinged to the door frame (1) above the hatch (2), and the other end is provided with a locking pin (32) and a hinge roller (33); the guide block (4) is fixed to the upper part of the hatch (2) and has a guide groove (42) extending in the vertical direction to accommodate the hinge roller (33) of the suspension hinge (3). The hatch latch (20) has a latch crank (201) with rollers at both ends. The rollers of the latch crank (201) engage with the lifting drive limiting surface (211) of the latch groove (21) fixedly installed on the door frame (1). The hatch latch (20) has a latch fork arm (203) in the middle. The handle shaft (18) is hinged to the lower middle part of the hatch (2). A handle (19) that drives the handle shaft (18) to rotate and a latch lever (17) that rotates with the handle shaft (18) are connected to it. The latch lever (17) can move in and out of the latch fork arm (203) of the hatch latch (20) during rotation. The latch lever (17) is also hinged to the step cam (15) through the lower connecting rod (16). The step-by-step cam (15) has a cam surface (152) adapted to accommodate the roller of the single lug (142) of the roller crank (14). The cam surface (152) includes a first surface and a second surface. The first surface is configured concentrically with the axis of rotation of the step-by-step cam (15) so that when the step-by-step cam (15) initially rotates, the roller of the single lug (142) of the roller crank (14) is not subjected to force within the cam surface (152). The second surface is located behind the first surface and has a distance from the step-by-step cam (15). The trajectory of the rotating shaft is such that when the step-by-step cam (15) rotates subsequently, the roller of the single ear (142) of the roller crank (14) is subjected to force in the cam surface (152) to drive the roller crank to move. The roller crank (14) is hinged to the locking rocker arm (8) through the connecting rod. The locking rocker arm (8) is hinged to the upper locking hook (6) through the push rod (7). The upper locking hook (6) is located above the locking pin (32) of the suspension hinge (3). The lower locking hook (5) is fixed on the hatch (2) and located below the locking pin (32).
2. The aircraft cabin door anti-sinking mechanism as described in claim 1, characterized in that, The suspension hinge (3) is hinged to the door frame (1) via the upper suspension lug (31).
3. The aircraft cabin door anti-sinking mechanism as described in claim 1, characterized in that, The guide block (4) is fixedly installed on the hatch (2) by means of the mounting base plate (41).
4. The aircraft cabin door anti-sinking mechanism as described in claim 1, characterized in that, The lower part of the lower connecting rod (16) is hinged to the double lugs of the latch lever (17), and the upper part is hinged to the double lug joint (151) of the step cam (15).
5. The aircraft cabin door anti-sinking mechanism as described in claim 1, characterized in that, The roller crank (14) is hinged to the middle lug of the transition rocker arm (12) via the middle connecting rod (13). One end of the transition rocker arm (12) is hinged to the hatch (2), and the other end of the transition rocker arm (12) is hinged to the rocker arm (10) via the upper connecting rod (11). The rocker arm (10) is connected to the locking rocker arm (8) via the rotating shaft (9).
6. The aircraft cabin door anti-sinking mechanism as described in claim 1, characterized in that, The anti-sinking mechanism forms three strokes by pulling the handle (19): In the first stroke, the handle (19) is initially in the closed position, the roller of the latch crank (201) is in the slot of the lifting drive limiting surface (211) of the latch groove (21), the hatch is completely closed, and neither the lower locking hook (5) nor the upper locking hook (6) is in contact with the locking pin (32). The handle (19) is pulled outward and upward, and the latch lever (17) of the handle shaft (18) moves to engage with the slot of the latch fork arm (203), and drives the lower connecting rod (16) to move downward, driving the step cam (15) to rotate. During this stroke, the roller of the single ear (142) of the roller crank (14) slides in the first curved surface, and the roller crank (14) remains stationary. Stroke 2: Continue to pull the handle (19) outward and upward. The latch lever (17) of the handle shaft (18) presses against the slot of the latch fork arm (203), driving the hatch latch (20) to rotate around the latch shaft (202). Under the reaction force of the latch groove (21), the hatch (2) moves upward. As the hatch (1) moves upward, the hinge roller (33) of the suspension hinge (3) moves to the bottom of the guide groove (42) of the guide block (4). The lower locking hook (5) moves upward synchronously and engages with the locking pin (32) of the suspension hinge (3). The step cam (15) continues to rotate. The cam surface (152) of the step cam (15) is concentric with the axis of rotation of the step cam (15). The roller of the single ear (142) of the roller crank (14) continues to slide in the first surface. The roller crank (14) remains stationary. Stroke 3: Continue to pull the handle (19) outward and upward. The step cam (15) continues to rotate. The roller of the single ear (142) of the roller crank (14) slides in the second curved surface of the step cam (15). The roller crank (14) rotates and drives the upper locking hook (6) to move downward through the connecting rod. It engages with the locking pin (32) of the suspension hinge (3). At this time, the lower locking hook (5) and the upper locking hook (6) hold the locking pin (32) together. At the same time, the hinge roller (33) engages with the guide groove (42) to lock the hatch (2) and the suspension hinge (3) together. Push the hatch (2) outward and upward. The hatch (2) rotates around the pivot of the suspension hinge (3).