Latch mechanism for storable cover plate

Abstract

A latch mechanism for a storable cover plate includes: a carriage frame mechanism configured to be mounted on a boxcar, the carriage frame mechanism enclosing an open large cavity; the sealing cover system is assembled on the carriage frame mechanism and used for shielding the open type large cavity, and the sealing cover system at least has an unfolding position state and a storage position state relative to the carriage frame mechanism; and the latch mechanism is configured on the sealing cover frame mechanism, and the latch mechanism at least has an unlocking state and a locking state, so that the sealing cover frame mechanism is in releasable joint with the carriage frame mechanism through the latch mechanism. According to the latch mechanism, the integrated lock tongue is adopted, the structure and the function are integrated, an existing lock tongue body and screw rod combination scheme is replaced, a spring is directly installed in a lock tongue cavity, and a bent structure at the tail end of a lock shell is omitted. Therefore, the number of parts is smaller, production and assembly are simpler and more practical, and the device is more stable and reliable after being used for a long time.

Description

Technical Field

[0001] The utility model relates to a latch mechanism for a retractable cover plate. Background Art

[0002] Traditionally, pickup trucks are widely used vehicles that can transport goods and passengers. Passengers are usually placed in the truck cab, while goods can be stored in the truck chassis. The truck bed is usually rectangular and open to the environment to facilitate loading and transporting large and / or oddly shaped goods. However, exposing the truck bed to the environment may leave the truck bed and / or goods unprotected. For example, the truck bed and / or goods may be exposed to dust, precipitation (such as rain, snow, hail), etc., Therefore, some truck owners purchase truck covers to protect the truck bed and the items stored in the truck.

[0003] Currently, models with an open bed need to be equipped with an openable bed cover to protect and shield the goods in the bed. And this kind of openable bed cover is usually a triple-fold cover. During the driving process of the vehicle, there will inevitably be bumps, and a locking structure needs to be set between the cover body and the frame. In a locking structure in the prior art, lock tongues are arranged on both sides of the cover body, and each lock tongue needs to be provided with an operating structure, which has a high cost. Moreover, this kind of operating mechanism lacks buffering for the reset action when the lock tongue is re-locked. The reset action of the lock tongue is too fast, and the feedback of the operating end to the hand is too large, affecting the operation.

[0004] In order to solve the defects of the traditional structure, the inventor developed a new structural solution. Referring to the patent document CN218934101U, a locking structure for a bed cover is disclosed, which is used to cooperate with the frame of the bed. The bed cover includes at least two flip-up cover units. The locking structure is fixed to the bottom of the cover unit through a mounting seat. The locking structure includes: a gear rotatably arranged on the mounting seat; a slide plate slidably arranged on the mounting seat, and a tooth portion meshing with the gear is arranged inside the slide plate; a lock tongue slidably arranged at the bottom of the cover unit, and the lock tongue is connected to the slide plate through a first connecting member; the lock tongue has a locking state in which it extends into the frame to limit the folding of the cover unit, and an unlocking state in which the gear drives the slide plate to slide, so that the slide plate drives the lock tongue to be received in the mounting seat, increasing the stability of the bed cover in the unfolded state and facilitating operation at the same time.

[0005] Based on the above patent literature, during the R & D and comparison processes, the inventors of the present disclosure found that there are certain defects, such as: 1. The lock tongue is assembled by two separate components, specifically the lock tongue body and the screw rod. The end of the screw rod is connected to the pull rope, the front end of the screw rod is threadedly connected to the lock tongue body, and a spring is sleeved on the screw rod. Due to the large number of components, the production and assembly are more complex; 2. In order to meet the use and installation of the spring on the screw rod, special structural processing is required at the end of the metal lock shell. The two sides at the end of the lock shell are bent inward and holes need to be formed, so the processing difficulty of the lock shell is relatively large; 3. Since multiple components work together, after long-term use, the structural accuracy of each component itself and the matching accuracy between them decrease, and it is easier to appear loose, resulting in unstable and incomplete operation of the locking mechanism. Summary of the Invention

[0006] In order to overcome the above deficiencies of the prior art, the present utility model provides a latch mechanism for a retractable cover.

[0007] The technical solution for the present utility model to solve its technical problems is: A latch mechanism for a retractable cover, comprising:

[0008] A carriage frame mechanism, configured to be installed on a truck carriage, and the carriage frame mechanism encloses an open large cavity;

[0009] A capping system, assembled on the carriage frame mechanism for shielding the open large cavity, and the capping system has at least a deployed position state and a retracted position state relative to the carriage frame mechanism;

[0010] A latch mechanism, configured on the capping frame mechanism, and the latch mechanism has at least an unlocked state and a locked state, so that the capping frame mechanism is releasably engaged with the carriage frame mechanism through the latch mechanism;

[0011] The latch mechanism includes:

[0012] A latch base plate, fixed to the capping frame mechanism;

[0013] A latch housing, assembled on the latch base plate, and a latch cavity is formed between the latch housing and the latch base plate;

[0014] A lock tongue, movably disposed in the latch cavity, one end of the lock tongue is a locking end, and the other end is a transmission end. The lock tongue has a lock tongue cavity with an opening;

[0015] A pull rope, connected to the transmission end of the lock body, and the pull rope is controlled by the user;

[0016] A limiting portion, located above the latch base plate, and the limiting portion extends into the lock tongue cavity through the opening;

[0017] The spring is arranged in the lock tongue cavity, one end of the spring contacts the limiting portion, and the other end contacts the inner wall of the lock tongue cavity.

[0018] When the latch mechanism is in the unlocked state, the cover frame mechanism can move relative to the carriage frame mechanism, so that the cover system can switch between the deployed position state and the stowed position state; when the latch mechanism is in the locked state, the cover frame mechanism forms a limited fit with the carriage frame mechanism through the latch mechanism, restricting the cover frame mechanism from moving relative to the carriage frame mechanism, so that the cover system continues to remain in the deployed position state;

[0019] The user pulls the pull cord backward to control the lock tongue to move backward, and the latch mechanism switches to the unlocked state, so that the locking end and the carriage frame mechanism are staggered in the vertical position, and the cover frame mechanism can move relative to the carriage frame mechanism;

[0020] When the user releases the pull rope, the spring acts on the lock tongue, causing the lock tongue to move forward so that the locking end coincides with the car frame mechanism in the vertical position, the latch mechanism switches to the locked state, and the cover frame mechanism cannot move relative to the car frame mechanism.

[0021] In some optional embodiments of the present invention, a connecting plate is attached to the carriage frame mechanism, the connecting plate is covered on the inner wall of the carriage frame mechanism, and the connecting plate is located between the carriage frame mechanism and the lock tongue.

[0022] Furthermore, the connecting plate includes a vertical portion, a first horizontal portion bent outward from one end of the vertical portion, and a second horizontal portion bent inward from the other end of the vertical portion;

[0023] The inner surface of the car frame mechanism has a first toothed side wall, and the outer surface of the vertical portion has a second toothed side wall, and the first toothed side wall and the second toothed side wall are engaged with each other so that the connecting plate is attached to the car frame mechanism.

[0024] More specifically, the first horizontal portion has a first accommodating groove, and the lower end of the carriage frame mechanism is inserted into the first accommodating groove;

[0025] The second horizontal portion has a second accommodating groove, and the inner side of the carriage frame mechanism has a positioning block, which is inserted into the second accommodating groove.

[0026] Preferably, the vertical portion is fixed to the vehicle frame structure by a first fastener.

[0027] In some optional embodiments of the present invention, the latch mechanism further comprises:

[0028] The backing plate is configured to be in the latch cavity, and the limiting portion is formed on the backing plate;

[0029] The first fastener connects the latch housing, the backing plate, and the latch bottom plate into one body;

[0030] The pull cord protection member is attached to the pull cord.

[0031] In some alternative embodiments of the present utility model, the capping system includes: a plurality of movable capping frame mechanisms, and capping plates assembled in each capping frame mechanism. The capping frame mechanisms divide the large cavity into a plurality of small cavities, and the capping plates are assembled in the large cavity.

[0032] In some alternative embodiments of the present utility model, the latch mechanism further includes a latch extension housing. One end of the latch extension housing abuts against the latch housing, and the other end of the latch extension housing is fixed to the capping plate by a second fastener. The latch extension housing encloses the connection portion between the transmission end and the pull cord.

[0033] Furthermore, the latch extension housing has a curved arc section, and the curved arc section gradually approaches the capping plate from the side close to the latch housing to the side far from the latch housing.

[0034] The beneficial effects of the present utility model are as follows:

[0035] First, it has a latch mechanism for locking or releasing the capping frame mechanism, so that the capping system can be switched between the deployed position state, the stored position state, and the standing position state relative to the carriage frame mechanism.

[0036] Second, an integrated latch tongue is adopted, with the structure and function integrated into one, replacing the existing combination scheme of the latch tongue body and the screw. The spring is directly installed in the latch tongue cavity, and the bent structure at the end of the lock shell is cancelled. Therefore, the number of parts is less, and it is more simple and practical in production and assembly, and is also more stable and reliable after long-term use. Description of the Drawings

[0037] Figure 1 It is a schematic diagram of a truck with a retractable capping of the present utility model.

[0038] Figure 2 It is a schematic structural diagram of the capping system in the retractable capping in the deployed position state.

[0039] Figure 3 It is a schematic structural diagram of the capping system in the retractable capping in the stored position state.

[0040] Figure 4 It is an exploded view of the structure of the retractable capping.

[0041] Figure 5 It is an exploded view of the latch mechanism in the retractable cover plate.

[0042] Figure 6 It is a partial structural cross-sectional view of the latch mechanism in the locked state.

[0043] Figure 7 It is a partial structural cross-sectional view of the latch mechanism in the unlocked state.

[0044] Figure 8 It is a partial schematic view of the connecting plate and the first longitudinal frame.

[0045] Figure 9 It is a comparison schematic view of the latch mechanism in the locked state and the unlocked state.

[0046] Figure 10 It is an exploded view of the structure of the latch mechanism.

[0047] Figure 11 It is a partial structural perspective view of the lock tongue cavity.

[0048] In the figure: 1. Retractable cover plate; 2. Freight car carriage; 3. Capping system; 3a. Expanded position state; 3b. Retracted position state; 31. Capping frame mechanism; 32. Cover plate; 32b. Small cavity; 4. Carriage frame mechanism; 4a. Open large cavity; 4b. First toothed side wall; 4c. Lower end of the carriage frame mechanism; 4d. Positioning block; 5. Latch mechanism; 5a. Unlocked state; 5b. Locked state; 51. Latch bottom plate; 52. Latch housing; 53. Latch cavity; 54. Lock tongue; 54a. Locking end; 54b. Driving end; 541. Lock tongue cavity; 541a. Opening; 541b. Front wall of the lock tongue cavity; 55. Pull rope; 56. Limiting part; 57. Spring; 58. Pad; 581. First fastener; 582. Pull rope protection member; 59. Latch extension housing; 591. Second fastener; 59a. Bent arc section; 6. Connecting plate; 61. Vertical part; 6a. Second toothed side wall; 62. First horizontal part; 621. First accommodating groove; 63. Second horizontal part; 631. Second accommodating groove; 64. Third fastener. Detailed implementation manners

[0049] The following further describes the present utility model in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments are only specific elaborations of the present utility model, and their purpose is to enable those skilled in the art to better understand the technical solutions of the present utility model, and should not be regarded as a limitation of the present utility model.

[0050] In the description of the present utility model, it should be noted that when terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0051] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, when terms such as "installation", "connection", "coupling" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0052] Embodiment 1

[0053] Referring to Figures 1 to 11 , a latch mechanism for a retractable cover plate, comprising:

[0054] A carriage frame mechanism 4, configured to be mounted on a freight car carriage 2, and the carriage frame mechanism 4 encloses an open large cavity 4a; in a specific embodiment, the carriage frame mechanism 4 presents a rectangular shape, matching the shapes of most freight car carriages 2 on the market.

[0055] A capping system 3, which is assembled on the carriage frame mechanism 4 and is used to shield the open large cavity 4a, thereby isolating the freight car carriage 2 from the outside and providing protection for the items stored in the freight car carriage 2. The capping system 3 has at least a deployed position state 3a and a retracted position state 3b relative to the carriage frame mechanism 4; specifically, when the capping system 3 is in the deployed position state 3a, each capping frame mechanism 31 (cover plate 32) is laid flat on the carriage frame mechanism 4 (freight car carriage 2) to close the large cavity; when the capping system 3 is in the retracted position state 3b, some or all of the capping frame mechanisms 31 (cover plates 32) are separated from the carriage frame mechanism 4 (freight car carriage 2) to partially or completely release the large cavity.

[0056] The latch mechanism 5 is configured on the cover frame mechanism 31. The latch mechanism 5 has at least an unlocked state 5a and a locked state 5b, so that the cover frame mechanism 31 is releasably engaged with the carriage frame mechanism 4 through the latch mechanism 5. Specifically, when the latch mechanism 5 is in the unlocked state 5a, the cover frame mechanism 31 can move relative to the carriage frame mechanism 4, so that the cover system 3 can switch between the deployed position state 3a and the stored position state 3b; when the latch mechanism 5 is in the locked state 5b, the cover frame mechanism 31 forms a limit fit with the carriage frame mechanism 4 through the latch mechanism 5, restricting the cover frame mechanism 31 from moving relative to the carriage frame mechanism 4, so that the cover system 3 continuously remains in the deployed position state 3a.

[0057] Preferably, the latch mechanism 5 includes: Refer to Figure 5 , Figure 10 , a latch bottom plate 51 fixed to the cover frame mechanism 31; a latch housing 52 assembled on the latch bottom plate 51, with a latch cavity 53 formed between the latch housing 52 and the latch bottom plate 51; a latch tongue 54 movably disposed in the latch cavity 53, one end of the latch tongue 54 being a locking end 54a and the other end being a transmission end 54b. The latch tongue 54 has a latch tongue cavity 54, and the latch tongue cavity 54 has an opening 541a, and the opening 541a is disposed on the side away from the cover plate 32; a pull cord 55 connected to the transmission end 54b of the lock body, and the pull cord 55 is controlled by the user; a limiting portion 56 located above the latch bottom plate 51, and the limiting portion 56 extends into the latch tongue cavity 54 through the opening 541a; a spring 57 disposed in the latch tongue cavity 54, one end of the spring 57 contacting the limiting portion 56 and the other end contacting the inner wall of the latch tongue cavity 54.

[0058] The working principle of the latch mechanism 5 with the above structure is as follows: The user pulls the pull cord 55 backward to control the latch tongue 54 to move backward (at most to the position where the front wall of the latch tongue cavity 54 abuts against the limiting portion 56), and the latch mechanism 5 switches to the unlocked state 5a, so that the locking end 54a and the carriage frame mechanism 4 are vertically displaced from each other, and the cover frame mechanism 31 can move relative to the carriage frame mechanism 4; when the user releases the pull cord 55, the spring 57 acts on the latch tongue 54 to make the latch tongue 54 move forward, so that the locking end 54a and the carriage frame mechanism 4 coincide vertically, and the latch mechanism 5 switches to the locked state 5b, and the cover frame mechanism 31 cannot move relative to the carriage frame mechanism 4.

[0059] Embodiment 2

[0060] Refer to Figures 6 to 8, in some alternative embodiments of the present utility model, a connecting plate 6 is attached to the carriage frame mechanism 4, the connecting plate 6 is wrapped on the inner wall of the carriage frame mechanism 4, and the connecting plate 6 is located between the carriage frame mechanism 4 and the locking tongue 54.

[0061] It should be noted that the connecting plate 6 is not an essential structural feature of this application, but when the connecting plate 6 is selected for use, it can bring additional effects. Specifically, during the working process, the latch mechanism 5 can indirectly lock with the carriage frame mechanism 4 through the connecting plate 6, and at the same time, the latch mechanism 5 does not directly contact the carriage frame mechanism 4, reducing the probability of damage to the latch mechanism 5 and the carriage frame mechanism 4, and playing an effective physical protection role. On the other hand, as an independently formed component, the connecting plate 6 has stronger plasticity and can change its structure and be produced and assembled according to the shape of different retractable covers 1 to meet the needs of various trucks; on the other hand, in order for the locking tongue 54 to move forward or backward smoothly, there must be a certain movement space between the locking tongue 54 and the carriage frame mechanism 4. If the movement space is too large, during the vehicle driving process, the cover system 3 (latch mechanism 5) will vibrate greatly relative to the carriage frame mechanism 4, which is likely to cause damage to the cover system 3. Therefore, the presence of the connecting plate 6 can fill the movement space to a certain extent, achieving the effect of reducing the vibration amplitude and effectively protecting the cover system 3.

[0062] In some alternative embodiments, a structural solution of the connecting plate 6 is provided, specifically: the connecting plate 6 includes a vertical portion 61, a first horizontal portion 62 bent outward from one end of the vertical portion 61, and a second horizontal portion 63 bent inward from the other end of the vertical portion 61. Preferably, the connecting plate 6 is an integral part made of the same material.

[0063] Among them, the inner surface of the carriage frame mechanism 4 has a first toothed side wall 4b, and the outer surface of the vertical portion 61 has a second toothed side wall 6a. The first toothed side wall 4b and the second toothed side wall 6a are meshed with each other, so that the connecting plate 6 is attached to the carriage frame mechanism 4. Among them, the inner surface of the carriage frame mechanism 4 has a first toothed side wall 4b, and the outer surface of the vertical portion 61 has a second toothed side wall 6a. The first toothed side wall 4b and the second toothed side wall 6a are meshed with each other, so that the connecting plate 6 is attached to the carriage frame mechanism 4. The first horizontal portion 62 has a first receiving groove 621, and the lower end of the carriage frame mechanism 4 is inserted into the first receiving groove 621; the second horizontal portion 63 has a second receiving groove 631, and the inner side of the carriage frame mechanism 4 has a positioning block 4d, and the positioning block 4d is inserted into the second receiving groove 631. With the above structural solution of the connecting plate 6, the connecting plate 6 is more stably connected to the carriage frame mechanism 4, and at the same time, the connecting plate 6 can wrap the edge of the carriage frame mechanism 4, so as to prevent the sharp edge of the metal carriage frame mechanism 4 from directly contacting the user's body or the cover system 3 (cover plate 32) and causing damage.

[0064] Regarding a more reliable fixing method of the connecting plate 6, on the original basis, the vertical portion 61 is further fixed to the carriage frame mechanism 4 by a third fastener 64.

[0065] Embodiment III

[0066] In some alternative embodiments of the present invention, referring to Figures 6 to 8 , the latch mechanism 5 further includes: a backing plate 58, which is disposed in the latch cavity 53, and the limiting portion 56 is formed on the backing plate 58; a first fastener 581, which connects the latch housing 52, the backing plate 58 and the latch bottom plate 51 into one body; a pull cord 55 protection member, which is attached to the pull cord 55. On the one hand, the backing plate 58 can play a role in adjusting the internal space size of the latch cavity 53, so that the latch tongue 54 is raised or lowered and adjusted to the optimal use position; on the other hand, the backing plate 58, as a structural transition component, makes the connection between the latch housing 52 and the latch bottom plate 51 more stable through the first fastener 581.

[0067] Embodiment IV

[0068] In some alternative embodiments of the present invention, referring to Figures 6 to 8 、 Figure 10, the latch mechanism 5 further includes a latch extension housing 59. One end of the latch extension housing 59 abuts against the latch housing 52, and the other end of the latch extension housing 59 is fixed to the cover plate 32 by a second fastener 591. The latch extension housing 59 encloses the connection portion between the transmission end 54b and the pull rope 55. The latch extension housing 59 has a curved arc section 59a, and the curved arc section 59a gradually approaches the cover plate 32 from the side close to the latch housing 52 to the side away from the latch housing 52. First, in some cases, the latch extension housing 59 can be considered as an extended structure of the latch housing 52, thus effectively protecting other components (such as the pull rope 55, the locking tongue 54, etc.) enclosed therein. Second, the presence of the connecting plate 6 makes the mating dimension of the second fastener 591 larger, so that the second fastener 591 plays a more reliable fastening function. Third, due to the certain dimensions of the components themselves, there must be a certain height difference between the locking tongue 54 and the cover plate 32, which indirectly causes the pull rope 55 to have a certain inclination in the height direction. Especially at the connection portion between the locking tongue 54 and the pull rope 55 (near the transmission end 54b of the locking tongue 54), the self-strength of the pull rope 55 in the non-straight state will be greatly weakened. Through the setting of the curved arc section 59a, the shape of the pull rope 55 near the transmission end 54b of the locking tongue 54 can be adapted, thus achieving a better shielding and protection effect on the pull rope 55.

[0069] Embodiment Five

[0070] Based on the structure of any of the foregoing embodiments, this embodiment provides a preferred structural solution for the cover system 3, specifically: Refer to FIGS. 1 to Figure 3 , the cover system 3 includes: a plurality of movable cover frame mechanisms 31, and cover plates 32 assembled in each cover frame mechanism 31. The cover frame mechanisms 31 divide the large cavity into a plurality of small cavities 32b, and the cover plates 32 are assembled in the large cavity. When each small cavity 32b is assembled with a cover plate 32 and the cover system 3 is in the deployed position state 3a, the large cavity is completely shielded by a plurality of cover plates 32.

[0071] It should be noted that other technical solutions of the present invention belong to the prior art, so they will not be elaborated here.

[0072] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A latch mechanism for a retractable cover plate, comprising: A carriage frame mechanism (4) configured to be mounted on a truck carriage (2), the carriage frame mechanism (4) enclosing an open large cavity (4a); A cover system (3) assembled on the carriage frame mechanism (4) for shielding the open large cavity (4a), the cover system (3) having at least a deployed position state (3a) and a retracted position state (3b) relative to the carriage frame mechanism (4); A latch mechanism (5) configured on the cover frame mechanism (31), the latch mechanism (5) having at least an unlocked state (5a) and a locked state (5b) such that the cover frame mechanism (31) is releasably engaged with the carriage frame mechanism (4) through the latch mechanism (5); Characterized in that The latch mechanism (5) includes: A latch base plate (51) fixed to the cover frame mechanism (31); A latch housing (52) assembled on the latch base plate (51), a latch cavity (53) being formed between the latch housing (52) and the latch base plate (51); A latch tongue (54) movably disposed in the latch cavity (53), one end of the latch tongue (54) being a locking end (54a) and the other end being a transmission end (54b), the latch tongue (54) having a latch tongue (54) cavity with an opening (541a); A pull rope (55) connected to the transmission end (54b) of the lock body, the pull rope (55) being controlled by a user; A limiting portion (56) located above the latch base plate (51), the limiting portion (56) extending into the latch tongue (54) cavity through the opening (541a); A spring (57) disposed in the latch tongue (54) cavity, one end of the spring (57) contacting the limiting portion (56) and the other end contacting the inner wall of the latch tongue (54) cavity.

2. The latch mechanism for a retractable cover plate according to claim 1, characterized in that: When the latch mechanism (5) is in the unlocked state (5a), the cover frame mechanism (31) can move relative to the carriage frame mechanism (4) such that the cover system (3) can switch between the deployed position state (3a) and the retracted position state (3b); when the latch mechanism (5) is in the locked state (5b), the cover frame mechanism (31) forms a limiting fit with the carriage frame mechanism (4) through the latch mechanism (5), restricting the cover frame mechanism (31) from moving relative to the carriage frame mechanism (4) such that the cover system (3) continuously remains in the deployed position state (3a); The user pulls the pull rope (55) backward to control the latch tongue (54) to move backward, and the latch mechanism (5) switches to the unlocked state (5a), causing the locking end (54a) and the carriage frame mechanism (4) to be vertically offset from each other, and the cover frame mechanism (31) can move relative to the carriage frame mechanism (4); The user releases the pull cord (55), and the spring (57) acts on the latch tongue (54), causing the latch tongue (54) to move forward so that the locking end (54a) coincides with the carriage frame mechanism (4) in the vertical position. The latch mechanism (5) switches to the locked state (5b), and the cover frame mechanism (31) cannot move relative to the carriage frame mechanism (4).

3. The latch mechanism for a retractable cover plate according to claim 1, characterized in that: A connecting plate (6) is attached to the carriage frame mechanism (4). The connecting plate (6) is wrapped around the inner wall of the carriage frame mechanism (4), and the connecting plate (6) is located between the carriage frame mechanism (4) and the latch tongue (54).

4. The latch mechanism for a retractable cover plate according to claim 3, characterized in that: The connecting plate (6) includes a vertical portion (61), a first horizontal portion (62) bent outward from one end of the vertical portion (61), and a second horizontal portion (63) bent inward from the other end of the vertical portion (61). The inner surface of the carriage frame mechanism (4) has a first toothed side wall (4b), and the outer surface of the vertical portion (61) has a second toothed side wall (6a). The first toothed side wall (4b) and the second toothed side wall (6a) mesh with each other, so that the connecting plate (6) is attached to the carriage frame mechanism (4).

5. The latch mechanism for a retractable cover plate according to claim 4, wherein: The first horizontal portion (62) has a first receiving groove (621), and the lower end of the carriage frame mechanism (4) is inserted into the first receiving groove (621). The second horizontal portion (63) has a second receiving groove (631), and the inner side of the carriage frame mechanism (4) has a positioning block (4d). The positioning block (4d) is inserted into the second receiving groove (631).

6. The latch mechanism for a retractable cover plate according to claim 4, characterized in that: The vertical portion (61) is fixed to the carriage frame mechanism (4) by a third fastener (64).

7. The latch mechanism for a retractable cover plate according to claim 1, characterized in that: The latch mechanism (5) further includes: A backing plate (58) configured in the latch cavity (53), and the limiting portion (56) is formed on the backing plate (58). A first fastener (581) that connects the latch housing (52), the backing plate (58), and the latch bottom plate (51) into one body. A pull cord (55) protection member attached to the pull cord (55).

8. The latch mechanism for a retractable cover plate according to claim 1, characterized in that: The cover system (3) includes: a plurality of movable cover frame mechanisms (31), and a cover plate (32) assembled in each cover frame mechanism (31). The cover frame mechanism (31) divides the large cavity into a plurality of small cavities (32b), and the cover plate (32) is assembled in the large cavity.

9. The latch mechanism for a retractable cover plate according to claim 8, wherein: The latch mechanism (5) further includes a latch extension housing (59). One end of the latch extension housing (59) abuts against the latch housing (52), and the other end of the latch extension housing (59) is fixed to the cover plate (32) by a second fastener (591). The latch extension housing (59) encloses the connection portion between the transmission end (54b) and the pull cord (55).

10. The latch mechanism for a retractable cover plate according to claim 9, wherein: The latch extension housing (59) has a curved arc section (59a), and the curved arc section (59a) gradually approaches the cover plate (32) from the side close to the latch housing (52) to the side away from the latch housing (52).

Images