CN216975484U

CN216975484U - Bidirectional ratchet mechanism and folding device using same

Info

Publication number: CN216975484U
Application number: CN202123338175.8U
Authority: CN
Inventors: 王力恒
Original assignee: Shanghai Wingtech Information Technology Co Ltd
Current assignee: Shanghai Wingtech Information Technology Co Ltd
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2022-07-15
Anticipated expiration: 2031-12-27

Abstract

The utility model discloses a bidirectional ratchet mechanism and a folding device applying the same, which relate to the technical field of flexible screens and comprise: the ratchet wheel assembly comprises a ratchet wheel shaft block, an elastic piece, a first ratchet, a second ratchet, a ratchet wheel and a reversing assembly; the pawl shaft block is symmetrically hinged with a first pawl and a second pawl, the first pawl and the second pawl are respectively used for being clamped with the ratchet wheel in a forward rotating state and a reverse rotating state, and the pawl shaft block is also provided with an elastic piece for pressing the first pawl and the second pawl to the ratchet wheel; and the reversing baffle of the reversing assembly is coaxial with the ratchet wheel and is arranged in a relative rotating mode, the reversing baffle is arranged on the radial outer side of the ratchet wheel and is positioned between the first pawl and the second pawl, and two ends of the reversing baffle are respectively used for enabling the first pawl and the second pawl to be separated from the ratchet of the ratchet wheel. The bidirectional ratchet mechanism can be applied to a folding device to realize the folding and unfolding functions of the folding device at any angle and any time.

Description

Bidirectional ratchet mechanism and folding device using same

Technical Field

The utility model relates to a flexible screen technical field especially relates to a folding device of two-way ratchet and applied this mechanism.

Background

With the development of technology, the screen occupation ratio of mobile phones is increasing, and the demand of people for large-screen and portable communication equipment is increasing, which has led to various methods for solving the problem, and among them, the flexible screen is most attractive. Compared with the traditional screen, the flexible screen has the characteristics of strong flexibility and flexibility, the size of the communication equipment can be reduced while the size of the screen is enlarged, and the higher requirement of people on the communication equipment is met.

At present, flexible screens in the market mostly adopt an outward folding screen and an inward folding screen. In general, the inward-folded screen is turned 180 degrees inwards to complete the folding function of the screen, and the screen can be protected more than the outward-folded screen, so that the inward-folded screen is popular. To realize the folding function of the inward-folding screen, the design of a folding hinge at a bending position is the biggest technical problem, namely, the design of the folding hinge at the bending position is the flexible screen.

Some existing hinge technologies can realize hovering at any angle in the process of turning over a screen, but cannot realize real-time reverse adjustment in the process of realizing functions, namely, if the screen needs to be turned clockwise in the process of turning over anticlockwise, the screen can only be turned over anticlockwise to a final state, and then can be turned over clockwise to a required angle, so that the operation process is complicated, and good folding experience cannot be provided for a user.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the present disclosure provides a bidirectional ratchet mechanism and a folding device using the same.

The present disclosure provides a bidirectional ratchet mechanism, comprising: the ratchet wheel assembly comprises a pawl shaft block, an elastic piece, a first pawl, a second pawl, a ratchet wheel and a reversing assembly;

the first pawl and the second pawl are symmetrical about the pawl shaft block, one end of the first pawl and one end of the second pawl are hinged with the pawl shaft block respectively, and the other end of the first pawl and the other end of the second pawl are used for being clamped with the ratchet wheel in a forward rotation state and a reverse rotation state respectively;

the elastic piece is arranged on the pawl shaft block and used for pressing the first pawl and the second pawl to the ratchet wheel;

the reversing assembly comprises a reversing baffle, the reversing baffle is coaxial with the ratchet wheel and is arranged in a relative rotating mode, the reversing baffle is arranged on the radial outer side of the ratchet wheel and is located between the first pawl and the second pawl, the first end of the reversing baffle is used for enabling the first pawl to be separated from the ratchet teeth of the ratchet wheel, and the second end of the reversing baffle is used for enabling the second pawl to be separated from the ratchet teeth of the ratchet wheel.

Optionally, the reversing device further comprises a knob, and the knob is connected with the reversing baffle.

Optionally, the reversing assembly further comprises a coaxial portion and a connecting portion, the coaxial portion is rotatably sleeved on a rotating shaft penetrating through the ratchet wheel, and the connecting portion is connected between the coaxial portion and the reversing baffle.

Optionally, a positioning protrusion is arranged on the knob, the positioning protrusion is sleeved outside the coaxial portion, and a groove used for being matched with the connecting portion in a circumferential positioning mode is formed in the positioning protrusion.

Optionally, both ends of the reversing baffle, which are used for being abutted to the first pawl and the second pawl, are arc-shaped structures, and the arc-shaped structures at both ends of the reversing baffle are symmetrical about the central axis of the reversing baffle.

Optionally, the two sides of the ratchet wheel are provided with a coaxial part and a connecting part which are connected with the reversing baffle.

Optionally, the reversing baffle plate further comprises a pawl side rotating plate, the pawl shaft block is arranged on the pawl side rotating plate, a first limiting part and a second limiting part are arranged on the pawl side rotating plate, and a limiting block is arranged on the reversing baffle plate; the limiting block is arranged between the first limiting part and the second limiting part and used for forming limiting fit with the first limiting part and the second limiting part respectively.

Alternatively, the plane of the ratchet wheel is perpendicular to the plane of the pawl-side rotation plate.

Optionally, when the reversing baffle enables the first pawl to be disengaged from the ratchet of the ratchet wheel, the ratchet wheel is clamped with the second pawl to prevent the claw section of the ratchet wheel from rotating from the first pawl to the second pawl; when the reversing baffle enables the second pawl to be separated from the ratchet of the ratchet wheel, the ratchet wheel is clamped with the first pawl and used for blocking the pawl section of the ratchet wheel to rotate towards the first pawl from the second pawl.

The folding device comprises a first rotating part, a second rotating part and the bidirectional ratchet mechanism, wherein the first rotating part is connected with a pawl shaft block, and the second rotating part is connected with a ratchet wheel.

Compared with the prior art, the technical scheme provided by the embodiment of the disclosure has the following advantages:

according to the bidirectional ratchet mechanism provided by the embodiment of the disclosure, the first pawl and the second pawl are symmetrically hinged on the pawl shaft block, the first pawl and the second pawl are respectively used for being clamped with the ratchet wheel in a forward rotation state and a reverse rotation state, and the pawl shaft block is further provided with an elastic piece for pressing the first pawl and the second pawl to the ratchet wheel; and the reversing baffle of the reversing assembly is coaxial with the ratchet wheel and is arranged in a relative rotating mode, the reversing baffle is arranged on the radial outer side of the ratchet wheel and is positioned between the first pawl and the second pawl, and two ends of the reversing baffle are respectively used for enabling the first pawl and the second pawl to be separated from the ratchet of the ratchet wheel. The bidirectional ratchet mechanism can be applied to the folding device to realize the folding and unfolding functions of the folding device at any angle and any time, and is simple in structure, small in assembly difficulty and low in production cost, and the damping sense can be adjusted through the shapes of the pawl and the ratchet, so that the user experience is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

FIG. 1 is a schematic view of a bi-directional ratchet mechanism in accordance with an embodiment of the present disclosure engaged with a pawl-side rotating plate;

FIG. 2 is a schematic view of a bidirectional ratchet mechanism according to an embodiment of the present disclosure;

FIG. 3 is a schematic view of a knob according to an embodiment of the disclosure;

FIG. 4 is a schematic view of a folding apparatus according to an embodiment of the present disclosure in a folded state;

fig. 5 is a schematic diagram illustrating a flattened state of the folding device according to the embodiment of the disclosure.

Wherein, 1, a pawl shaft block; 2. an elastic member; 31. a first pawl; 32. a second pawl; 4. a ratchet wheel; 51. a reversing baffle; 52. a connecting portion; 6. a pawl-side rotation plate; 71. a first limiting part; 72. a second limiting part; 8. a knob; 91. a first rotating section; 92. a second rotating part; 10. a housing.

Detailed Description

In order that the above objects, features and advantages of the present disclosure may be more clearly understood, aspects of the present disclosure will be further described below. It should be noted that the embodiments and features of the embodiments of the present disclosure may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced in other ways than those described herein; it is to be understood that the embodiments disclosed in the specification are only a few embodiments of the present disclosure, and not all embodiments.

Referring to fig. 1 and 2, a bidirectional ratchet mechanism provided in an embodiment of the present disclosure includes: the ratchet wheel comprises a pawl shaft block 1, an elastic piece 2, a first pawl 31, a second pawl 32, a ratchet wheel 4 and a reversing component;

the first pawl 31 and the second pawl 32 are symmetrical about the pawl shaft block 1, one end of the first pawl 31 and one end of the second pawl 32 are hinged with the pawl shaft block 1 respectively, and the other end of the first pawl 31 and the other end of the second pawl 32 are used for being clamped with the ratchet wheel 4 in a forward rotation state and a reverse rotation state respectively;

the elastic member 2 is provided on the pawl shaft block 1 for pressing the first pawl 31 and the second pawl 32 toward the ratchet wheel 4;

the reversing assembly comprises a reversing baffle 51, the reversing baffle 51 is coaxial with the ratchet 4 and is arranged in a relative rotating mode, the reversing baffle 51 is arranged on the radial outer side of the ratchet 4 and is located between the first pawl 31 and the second pawl 32, the first end of the reversing baffle 51 is used for enabling the first pawl 31 to be disengaged from the ratchet teeth of the ratchet 4, and the second end of the reversing baffle 51 is used for enabling the second pawl 32 to be disengaged from the ratchet teeth of the ratchet 4.

Specifically, the elastic member 2 may be two elastic pieces, the end portions of which are respectively abutted against the sides of the first pawl 31 and the second pawl 32 facing away from the ratchet 4, and in the pawl shaft block 1, a first shaft for being engaged with the first pawl 31 and the second pawl 32 and a second shaft for being engaged with the elastic pieces are respectively arranged; the above-described elastic member 2 may also be a torsion spring provided at the end portions of the first pawl 31 and the second pawl 32. In more detail, the reversing shutter 51 is disposed on the radial outer side of the ratchet 4 without contact therebetween, and there is a state where the reversing shutter 51 is not in contact with any one of the first pawl 31 and the second pawl 32 when it is disposed between the first pawl 31 and the second pawl 32; the outer circumference of the ratchet wheel 4 is provided with a plurality of rigid ratchet teeth, the clamping ends of the first pawl 31 and the second pawl 32 are matched with the tooth grooves of the ratchet wheel 4 and are respectively used for being abutted against the ratchet teeth when the ratchet wheel 4 rotates in the forward direction and rotates in the reverse direction, and in some embodiments, the damping feeling can be adjusted by adjusting the shapes of the first pawl 31 and the second pawl 32 and the shapes and the number of the ratchet teeth so as to improve the user experience.

The bidirectional ratchet mechanism can realize reversing rotation or hovering of the folding device at any angle, when the reversing baffle 51 lifts the first pawl 31 or the second pawl 32 blocking the ratchet at one side when the folding device rotates, the ratchet 4 can rotate towards the unblocked side to realize reversing and rotating of the folding device; when the first pawl 31 and the second pawl 32 are engaged with the ratchet wheel 4 at the same time, the ratchet wheel 4 cannot rotate, the folding device is in a hovering state, and an included angle of the folding device during suspension can be set by adjusting the number of the ratchet teeth on the ratchet wheel 4.

In some embodiments, as shown in fig. 1 to 3, a knob 8 is further included, and the knob 8 is connected to the direction-changing baffle 51. Specifically, the knob 8 may be directly connected to the reversing shutter 51, or indirectly connected to the reversing shutter 51 through another member, so that the first pawl 31 or the second pawl 32 is biased by the reversing shutter 51 to be disengaged from the ratchet teeth and released from the ratchet 4. Preferably, the reversing baffle 51 has an arc structure with the same curvature as the outer circumference of the ratchet 4, so as to prevent friction with the ratchet 4 when the reversing baffle 51 is rotated, and avoid wear of parts.

In some embodiments, the reversing assembly further comprises a coaxial portion rotatably sleeved on the rotating shaft passing through the ratchet 4, and a connecting portion 52 connected between the coaxial portion and the reversing baffle 51. More specifically, the ratchet wheel 4 is provided with a limit groove which is used for being matched with the coaxial part, and the end surface of the coaxial part is abutted against the end surface of the ratchet wheel 4; the connecting portion 52 may have a plate-like structure or a rod-like structure. Preferably, the connection point of the rod-shaped connecting part 52 and the reversing baffle 51 is located on the plane of the central axis of the reversing baffle 51, so that the two ends of the reversing baffle 51 are balanced. Preferably, an adhesive is provided on the contact surface of the reversing assembly and the knob 8; because the slot is arranged between the positioning bulge and the connecting part 52, the torque applied to the knob 8 is transmitted to the reversing baffle plate 51 through the connecting part 52, the contact surface of the positioning bulge and the connecting part 52 is always provided with a part subjected to pressure load, and the connection is carried out by selecting a bonding mode, so that the connection strength can be ensured, and the cost can be saved. In other embodiments, the reversing assembly and the knob 8 may be connected by magnetic attraction or screw connection.

In some embodiments, the knob 8 is provided with a positioning protrusion, the positioning protrusion is sleeved outside the coaxial portion, and the positioning protrusion is provided with a slot for circumferentially positioning and matching with the connecting portion 52. Specifically, the positioning protrusion and the coaxial portion are both hollow columnar structures, and the outer diameter of the coaxial portion is equal to the inner diameter of the positioning protrusion; the slots on the positioning protrusions can be matched with only part of the connecting parts 52, so that the connecting parts 52 have the functions of connecting the coaxial parts with the reversing baffle 51 and transmitting the external force applied to the knob 8 to the reversing baffle 51.

In some embodiments, both ends of the reversing shutter 51 for abutting against the first pawls 31 and the second pawls 32 are arc-shaped structures, and the arc-shaped structures of both ends of the reversing shutter 51 are symmetrical about a central axis of the reversing shutter 51. Specifically, the reversing baffle 51 with two ends of arc-shaped structure can avoid scratching the surfaces of the first pawl 31 and the second pawl 32 when applying force to the first pawl 31 and the second pawl 32; in addition, the arc structures at the two ends of the baffle are symmetrically arranged about the central axis of the reversing baffle 51, so that the whole stress of the reversing assembly is more uniform, the abrasion of the reversing assembly is reduced, and the service life of the reversing assembly is prolonged.

In some embodiments, both sides of the ratchet 4 are provided with coaxial portions and connecting portions 52 connected to the direction change flapper 51. Specifically, the reversing assembly is symmetrically arranged about the ratchet wheel 4, and two sides of the ratchet wheel 4 are attached to the coaxial portion, so that the reversing baffle 51 is positioned conveniently.

In some embodiments, the ratchet wheel further comprises a ratchet wheel side rotating plate 6, the ratchet wheel shaft block 1 is arranged on the ratchet wheel side rotating plate 6, a first limiting part 71 and a second limiting part 72 are arranged on the ratchet wheel side rotating plate 6, and a limiting block is arranged on the reversing baffle 51; the limiting block is arranged between the first limiting part 71 and the second limiting part 72 and is used for forming limiting fit with the first limiting part 71 and the second limiting part 72 respectively. In more detail, when the reversing assembly is symmetrically disposed about the ratchet 4, the first limiting portion 71, the second limiting portion 72 and the limiting block are correspondingly symmetrically disposed about the ratchet 4. The first limiting part 71, the second limiting part 72 and the limiting blocks can prevent the reversing baffle 51 from being excessively rotated to cause the position where the reversing baffle is separated from the position between the first pawl 31 and the second pawl 32 to be incapable of being reset after the first pawl 31 or the second pawl 32 is lifted.

In some embodiments, the plane of the ratchet wheel 4 is perpendicular to the plane of the pawl-side rotation plate 6. In more detail, as shown in fig. 4, in some embodiments, the knob 8 is further provided with a cover 10, and when the folding device is unfolded and flat, the outer circumference of the cover 10 is not lower than the flat surfaces of the two sides of the folding device; the outer cover 10 with a larger diameter is arranged outside the knob 8, so that the knob 8 can be conveniently rotated by a user, and the appearance integrity of the folding device is improved. In addition, the ratchet 4 and the pawl-side rotation plate 6, which are disposed perpendicularly to each other, are easy to process, enabling production costs to be reduced.

In some embodiments, when the reversing baffle 51 disengages the first pawl 31 from the ratchet teeth of the ratchet wheel 4, the ratchet wheel 4 is engaged with the second pawl 32 to block the pawl section of the ratchet wheel 4 from rotating from the first pawl 31 to the second pawl 32; when the reversing baffle 51 enables the second pawl 32 to be disengaged from the ratchet teeth of the ratchet wheel 4, the ratchet wheel 4 is clamped with the first pawl 31, and the pawl section of the ratchet wheel 4 is blocked from rotating from the second pawl 32 to the first pawl 31. In more detail, in the above embodiment, when the first pawl 31 is engaged with the ratchet wheel 4, it abuts against the surface of the tooth groove close to the second pawl 32; when the second pawl 32 is clamped with the ratchet wheel 4, the second pawl abuts against the surface, close to the first pawl 31, in the tooth groove; therefore, the rotation direction of the knob 8 is the same as that of the ratchet wheel 4, and the operation is convenient for a user.

As shown in fig. 1 and 5, some embodiments of the present disclosure further provide a folding device, which includes a first rotating portion 91 and a second rotating portion 92, and further includes the above-mentioned bidirectional ratchet mechanism, wherein the first rotating portion 91 is connected to the pawl shaft block 1, and the second rotating portion 92 is connected to the ratchet 4. Specifically, only one bidirectional ratchet mechanism may be provided between the first rotating portion 91 and the second rotating portion 92, or one bidirectional ratchet mechanism may be provided on each of both sides of the apparatus.

The folding device disclosed in the above embodiment is described below with reference to a specific use mode:

when the folding device is suspended at any angle, the first pawl 31 and the second pawl 32 block the ratchet wheel 4 to prevent the ratchet wheel 4 from rotating, so that the first rotating part 91 and the second rotating part 92 are prevented from rotating relatively to realize screen hovering; when the folding device needs to be folded, the knob 8 is rotated until the limiting block on the reversing baffle 51 is clamped by the first limiting part 71 or the second limiting part 72, and the corresponding reversing baffle 51 lifts the first pawl 31 or the second pawl 32 clamped in the ratchet 4, so that the ratchet 4 has no blocking effect on the folding of the first rotating part 91 and the second rotating part 92 in the direction, and the folding device can be folded at any angle; after the first rotating part 91 and the second rotating part 91 rotate to the expected positions, the knob 8 is rotated again, so that the limit block of the reversing baffle 51 is separated from the first limit part 71 or the second limit part 72, the reversing baffle 51 is positioned between the first pawl 31 and the second pawl 32, the first pawl 31 and the second pawl 32 are clamped with the ratchet wheel 4 again, the ratchet wheel 4 is prevented from rotating, and therefore the first rotating part 91 and the second rotating part 92 are prevented from rotating relatively, and the folding device can be suspended.

The folding device can be applied to flexible screens, electronic products with folding functions, small and medium-sized mechanical structures needing to be folded and the like.

It will be understood that the terms "upper," "lower," "front," "rear," "left," "right," "forward," "reverse," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and to simplify the description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular orientation, and thus should not be construed as limiting the present application.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present disclosure, which enable those skilled in the art to understand or practice the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bi-directional ratchet mechanism, comprising: the ratchet wheel comprises a pawl shaft block (1), an elastic piece (2), a first pawl (31), a second pawl (32), a ratchet wheel (4) and a reversing assembly;

the first pawl (31) and the second pawl (32) are symmetrical about the pawl shaft block (1), one end of the first pawl (31) and one end of the second pawl (32) are hinged to the pawl shaft block (1) respectively, and the other end of the first pawl (31) and the other end of the second pawl (32) are used for being clamped with the ratchet wheel (4) in a forward rotation state and a reverse rotation state respectively;

the elastic piece (2) is arranged on the pawl shaft block (1) and is used for pressing the first pawl (31) and the second pawl (32) to the ratchet wheel (4);

the reversing assembly comprises a reversing baffle (51), the reversing baffle (51) and the ratchet wheel (4) are coaxially and relatively rotatably arranged, the reversing baffle (51) is arranged on the radial outer side of the ratchet wheel (4) and is positioned between the first pawl (31) and the second pawl (32), the first end of the reversing baffle (51) is used for enabling the first pawl (31) to be disengaged from the ratchet teeth of the ratchet wheel (4), and the second end of the reversing baffle (51) is used for enabling the second pawl (32) to be disengaged from the ratchet teeth of the ratchet wheel (4).

2. The bidirectional ratchet mechanism of claim 1, further comprising a knob (8), wherein the knob (8) is connected to the reversing flapper (51).

3. The bidirectional ratchet mechanism of claim 2, wherein the reversing assembly further comprises a coaxial portion rotatably sleeved on a rotating shaft passing through the ratchet (4) and a connecting portion (52), wherein the connecting portion (52) is connected between the coaxial portion and the reversing flapper (51).

4. The bidirectional ratchet mechanism according to claim 3, wherein a positioning protrusion is provided on the knob (8), the positioning protrusion is sleeved outside the coaxial portion, and a slot for circumferential positioning and matching with the connecting portion (52) is provided on the positioning protrusion.

5. A bidirectional ratchet mechanism according to claim 3, characterized in that both ends of the reversing flapper (51) for abutting against the first pawl (31) and the second pawl (32) are arc-shaped structures, and the arc-shaped structures of both ends of the reversing flapper (51) are symmetrical with respect to a central axis of the reversing flapper (51).

6. A bidirectional ratchet mechanism according to claim 3, characterized in that the ratchet wheel (4) is provided on both sides with the coaxial portion and the connecting portion (52) connected with the reversing flapper (51).

7. The bidirectional ratchet mechanism according to claim 6, further comprising a pawl-side rotation plate (6), wherein the pawl shaft block (1) is provided on the pawl-side rotation plate (6), the pawl-side rotation plate (6) is provided with a first stopper portion (71) and a second stopper portion (72), and the direction change flapper (51) is provided with a stopper; the limiting block is arranged between the first limiting part (71) and the second limiting part (72) and used for forming limiting fit with the first limiting part (71) and the second limiting part (72) respectively.

8. The bidirectional ratchet mechanism according to claim 7, wherein the plane in which the ratchet (4) is located is perpendicular to the plane in which the pawl-side rotation plate (6) is located.

9. The bidirectional ratchet mechanism according to any one of claims 1 to 8, wherein when the reversing lever (51) disengages the first pawl (31) from the ratchet teeth of the ratchet wheel (4), the ratchet wheel (4) is engaged with the second pawl (32) for blocking the rotation of the ratchet wheel (4) from the first pawl (31) to the second pawl (32); the reversing baffle (51) enables the second pawl (32) to be disengaged from the ratchet teeth of the ratchet wheel (4), and the ratchet wheel (4) is clamped with the first pawl (31) and used for blocking the pawl section of the ratchet wheel (4) from rotating towards the first pawl (31) from the second pawl (32).

10. A folding device comprising a first rotating part (91) and a second rotating part (92), characterized by further comprising a bidirectional ratchet mechanism according to claims 1 to 9, said first rotating part (91) being connected to said pawl shaft block (1), said second rotating part (92) being connected to said ratchet wheel (4).