Non-return device for ramp recovery

Abstract

The non-return device comprises a ratchet head, a pawl and a spring, the pawl is located on one side of the ratchet head, the spring is located on the side, away from the ratchet head, of the pawl, in the loose state, the spring pushes the pawl to be connected into the ratchet head, a shifting rod is arranged between the pawl and the ratchet head, and the shifting rod is provided with an arc-shaped face and a tangent plane used for avoiding the pawl. The shifting rod is rotated to the arc-shaped surface to contact the pawl to push the pawl to leave the ratchet head. The deflector rod with a special structure is arranged between the ratchet head and the pawl, the deflector rod is rotated to push the pawl to leave, limitation is relieved, the deflector rod and ratchet structure is simplified, installation and operation are convenient, the contact area of the ratchet head and the pawl is increased, and reliability and safety in the recovery process are guaranteed.

Description

Technical Field

[0001] This utility model relates to a rail vehicle accessory, and more particularly to a backflow prevention device for ramp recovery. Background Technology

[0002] When retracting a heavy-duty emergency evacuation door, a backflow prevention structure must be installed to prevent the ramp from unfolding due to gravity and to ensure a safe and reliable retrieval process.

[0003] Patent application CN 112141146 A discloses a vehicle emergency evacuation door ramp retraction mechanism, which includes a ratchet, a pawl, and a crank. The ratchet is clamped on both sides of the crank crank, and the pawl is located below the ratchet, with its tip extending into the ratchet's tooth groove to restrict the ratchet's rotation in one direction. A shaped boss is provided on one side of the crank crank; as the crank crank rotates, the shaped boss pushes the pawl away from the ratchet, allowing the ratchet to rotate in both directions. In this design, the ratchet's thickness is limited, resulting in a small contact area with the pawl and low reliability. During evacuation door retraction, to ensure effective contact between the pawl and ratchet, a sliding groove, boss, or other structure is required on the mounting frame to keep the crank crank in an elevated state, making the structure complex. Utility Model Content

[0004] Purpose of the utility model: The purpose of this utility model is to provide a simplified anti-reverse device for ramp recovery.

[0005] Technical solution: The present invention provides a ramp recovery anti-reverse device, comprising a ratchet head, a pawl, and a spring. The pawl is located on one side of the ratchet head, and the spring is located on the side of the pawl away from the ratchet head. In the relaxed state, the spring pushes the pawl to engage with the ratchet head. A lever is provided between the pawl and the ratchet head. The lever has an arc-shaped surface and a tangential surface for avoiding the pawl. Rotating the lever until the arc-shaped surface contacts the pawl pushes the pawl away from the ratchet head.

[0006] Preferably, the lever is connected to a handle that drives the lever to rotate.

[0007] Preferably, the ramp recovery anti-reverse device includes a housing with a mounting groove, a ratchet head located in a semi-circular groove on one side of the mounting groove, and a pawl, spring, and lever located in a semi-circular groove on the other side of the mounting groove.

[0008] Preferably, the side wall of the semicircular groove B is provided with a pin hole with a semicircular cross section, and the top of the pawl is provided with a semicircular pin shaft that mates with the pin hole. The pawl is connected to the housing through the pin shaft and the pin hole.

[0009] Preferably, the outer casing and handle are provided with a through hole for preventing the handle from rotating, and a detachable limiting pin is connected inside the through hole.

[0010] Preferably, the mounting groove is provided with a cover plate.

[0011] Preferably, the pivots of the lever, pawl, and ratchet head are parallel.

[0012] Preferably, the cross-sections of the pawl and the lever are mirror-symmetrically distributed along the centerline of the ratchet head.

[0013] Preferably, the ratchet head has a keyway in the middle for connecting to the ramp recovery disc.

[0014] Beneficial effects: Compared with the prior art, this utility model has the following advantages: 1. Simplified structure: A specially structured lever is set between the ratchet head and the pawl. Rotating the lever pushes the pawl away, simplifying the lever and ratchet head structure, making it easy to install and operate; 2. Safe and reliable: The contact surface between the pawl and the ratchet head is increased, increasing the connection reliability and improving the load-bearing capacity. It can adapt to evacuation door systems under heavy load conditions and can ensure the safety of emergency evacuation door release and retraction; 3. Compact layout and small size. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the anti-reverse device for ramp recovery according to this utility model.

[0016] Figure 2 This is a schematic diagram of the internal structure of the anti-reverse device for ramp recovery according to this utility model.

[0017] Figure 3 This is a schematic diagram of the anti-reverse device for ramp recovery in the unidirectional operating state of this utility model;

[0018] Figure 4 This is a schematic diagram of the anti-reverse device for ramp recovery of this utility model in a bidirectional operating state. Detailed Implementation

[0019] The technical solution of this utility model will be further described below with reference to the accompanying drawings.

[0020] like Figure 1 , Figure 2 The ramp recovery anti-reverse device of this utility model is mainly composed of a pawl 8, a ratchet head 3, and a housing 1.

[0021] A ratchet head 3 is rotatably connected to the outer casing 1. The ratchet head 3 has teeth on its outer circumference and a keyway in the middle. The keyway is used to connect to the ramp pull belt recovery disc. A pawl 8 is located on one side of the ratchet head 3. Its top is rotatably connected to the outer casing 1 and can swing around the connection point at a certain angle. Its bottom has ratchet teeth that cooperate with the outer circumference of the ratchet head 3. A spring 9 is provided on the outer casing 1. The two ends of the spring 9 are respectively connected to the outer casing 1 and the outer side of the pawl 8 (the side away from the ratchet head 3). In the relaxed state, the spring 9 pushes the bottom teeth of the pawl 8 to insert into the tooth groove on the outer circumference of the ratchet head 3, restricting the unidirectional rotation of the ratchet head 3. A lever 10 is rotatably connected to the outer casing 1 between the pawl 8 and the ratchet head 3. The rotation axes of the lever 10, the pawl 8, and the ratchet head 3 are parallel. The lever 10 has an arc-shaped surface and a cut-off surface of the arc-shaped surface. When the lever 10 rotates and the arc-shaped surface contacts the inner side of the pawl 8 (near the ratchet head 3), it pushes the pawl 8, causing the bottom of the pawl 8 to move away from the tooth groove of the ratchet head 3. The ratchet head 3 can rotate in both directions. When the lever 10 rotates, the arc-shaped surface moves away from the inner side of the pawl 8, and the cut-off surface avoids the pawl 8. The bottom teeth of the pawl 8 are inserted into the outer peripheral tooth groove of the ratchet head 3.

[0022] The lever 10 is connected to the handle 2, which is arranged radially along the lever 10. The length of the handle 2 is increased to increase torque and reduce the driving force required to rotate the lever 10. The handle 2 and the housing 1 are provided with through holes for the insertion of the limiting pin 7. When the through holes of the handle 2 and the housing 1 are aligned, the limiting pin 7 is inserted to prevent the handle from driving the lever 10 to rotate, so that the lever 10 can maintain a certain state. For example, it can overcome the elastic force of the spring 9 to keep the pawl 8 in the disengaged state, or it can use the tangential surface to avoid the pawl 8 so that the pawl 8 is connected to the ratchet head 3.

[0023] The outer casing 1 has a gourd-shaped mounting groove. The ratchet head 3 is located in a semi-circular groove A on one side of the mounting groove, while the pawl 8 and spring 9 are located in a semi-circular groove B on the other side of the mounting groove. The side wall of the semi-circular groove B has a pin hole with a semi-circular cross-section. The top of the pawl 8 has a semi-circular pin that mates with the pin hole. The pin is inserted into the pin hole, allowing the pawl 8 and the semi-circular groove B to rotate and connect, so that the pawl 8 can swing around the pin hole at a certain angle. The mounting groove has a cover plate 4 with mounting holes on both sides. The cover plate 4 is connected to the outer casing 1 by screws 6 and washers 5.

[0024] To ensure symmetrical force distribution, semi-circular pin holes are symmetrically provided on the side walls on both sides of the centerline of the mounting groove (the horizontal centerline in the figure, which can also be called the centerline of the ratchet head 3). There are two pawls 8, which are inserted into the pin holes in a mirror image symmetrically. Correspondingly, the axis of the lever 10 is located on the centerline of the mounting groove. The cross-section of the lever 10 is symmetrical about the left and right sides along the centerline of the mounting groove. When the lever 10 is in a neutral position, when the arc surface contacts the inner side of the two pawls 8 at the same time, the two pawls 8 are lifted up at the same time and leave the ratchet head 3. The ratchet head 3 can rotate freely in both directions. When the lever rotates, the arc surface contacts only one pawl 8. The contacted pawl 8 is lifted up, overcoming the elastic force of the spring 9, and leaves the ratchet head 3. The remaining pawl 8 contacts the ratchet head 3, restricting the unidirectional rotation of the ratchet head 3.

[0025] When using, such as Figure 3 , Figure 4 Rotate the operating handle 2 counterclockwise until the through hole aligns with the upper through hole of the outer casing. Insert the limit pin 7 into the hole for positioning. Under external force, the ratchet head 3 can only rotate clockwise, controlling the external rotation mechanism and preventing backflow. Rotate the operating handle 2 clockwise until the through hole aligns with the lower through hole of the outer casing 1, and position it using the limit pin 7. At this time, the ratchet head 3 is in the neutral position and can rotate freely left and right under external force, facilitating easy release of the emergency evacuation door in an emergency. Before opening the emergency evacuation door, personnel must first rotate the handle clockwise to put its backflow prevention mechanism in the neutral position, at which point the door system can open smoothly. When retracting the emergency evacuation door, rotate the operating handle counterclockwise to ensure backflow prevention and safety.

Claims

1. A ramp recovery anti-reverse device, comprising a ratchet head (3), a pawl (8), and a spring (9), wherein the pawl (8) is located on one side of the ratchet head (3), and the spring (9) is located on the side of the pawl away from the ratchet head (3), and the spring (9) pushes the pawl (8) to engage with the ratchet head, characterized in that, The pawl (8) and the ratchet head (3) are provided with a push rod (10), the push rod (10) has an arc surface and a cutting surface for avoiding the pawl (8), and the push rod (10) is rotated to the arc surface to contact the pawl (8) and push the pawl (8) away from the ratchet head (3).

2. The reverse preventing device for ramp retrieval according to claim 1, characterized by The push rod (10) is connected with a handle (2) for driving the push rod to rotate.

3. The reverse preventing device for ramp retrieval according to claim 2, characterized by The slope recovery non-return device comprises a shell (1), the shell (1) is provided with a mounting groove, the ratchet head (3) is located in a semicircular groove A on one side of the mounting groove, and the pawl (8), the spring (9) and the push rod (10) are located in a semicircular groove B on the other side of the mounting groove.

4. The reverse preventing device for ramp retrieval according to claim 3, characterized by The shell (1) and the handle (2) are provided with a through hole for preventing the handle (2) from rotating, and a detachable limiting pin (7) is connected in the through hole.

5. The reverse preventing device for ramp retrieval according to claim 3, characterized by The mounting groove is provided with a cover plate (4).

6. The reverse preventing device for ramp retrieval according to claim 3, characterized by The side wall of the semicircular groove B is provided with a pin hole with a semicircular cross section, the top end of the pawl (8) is provided with a semicircular pin shaft matched with the pin hole, and the pawl (8) is connected with the shell through the pin shaft and the pin hole.

7. The rollback inhibitor for a ramp according to claim 1, characterized by The rotation axes of the push rod (10), the pawl (8) and the ratchet head (3) are parallel.

8. The reverse preventing device for ramp recycling according to claim 1 or 6, characterized by The cutting surfaces of the pawl (8) and the push rod (10) are distributed in mirror image symmetry along the center line of the ratchet head (3).

9. The rollback inhibitor for ramp recycling according to claim 1, characterized in that, The ratchet head (3) is provided with a key groove in the middle for connecting the slope recovery disc.

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