Rear hoop adjusting device

Abstract

The utility model relates to a rear hoop adjusting device, which is used for adjusting the circumference of a rear hoop of a safety helmet, and comprises a shell, a power part for driving the rear hoop to tighten or loosen and a locking part for limiting the rear hoop to automatically loosen, the locking part comprises a locking wheel which is fixedly arranged relative to the shell and a locking claw which is fixedly arranged relative to the power part; the locking wheel is provided with a plurality of groups of wheel teeth which are distributed in an annular array, the number of teeth of each group of wheel teeth is equal to that of teeth of the locking claws, and each group of wheel teeth is provided with a high tooth and a plurality of short teeth, so that only one locking claw abuts against one high tooth for limiting after each locking claw rotates one tooth position; the back hoop has the advantages that the abutting effect is good, and meanwhile the back hoop can be loosened and adjusted conveniently.

Description

Technical Field

[0001] The utility model relates to the technical field of labor protection products, in particular to a rear hoop adjusting device. Background Art

[0002] The existing safety helmet includes a helmet body, a rear hoop built into the helmet body, and an adjusting device for adjusting the circumference of the rear hoop. The adjusting device usually includes a shell for the rear hoop to pass through, a power part arranged in the shell, and at least two locking parts that cooperate with each other to ensure that the enclosed size of the rear hoop does not change.

[0003] When in use, the power unit rotates forward to drive the rear hoop to move relative to each other, and then the circumference of the rear hoop is adjusted to adapt to the head sizes of different operators. When the rear hoop is adjusted to the preset position, the locking claw and the gear teeth of the locking unit are unidirectionally pressed against the limit to limit the automatic reversal of the power unit. When the rear hoop needs to be loosened, the power unit is adjusted to reverse. During this process, the front end of the locking claw will be subjected to a radial force and a circumferential force, so that the locking claw can both rotate and deform to disengage from the gear teeth, so that the rear hoop can be loosened better.

[0004] It can be known that when the tooth height of the gear teeth is larger, the locking claw and the gear teeth have a better contact effect. Conversely, when reversing, the locking claw needs to produce a larger deformation to disengage from the gear teeth; and when the tooth height of the gear teeth is smaller, although the locking claw is easy to disengage from the gear teeth during the reversal process, the contact effect between the locking claw and the gear teeth will become weaker, especially after long-term use causing the gear teeth to wear, it is more likely to cause the rear hoop to loosen automatically.

[0005] Therefore, it is urgent for those skilled in the art to provide a rear hoop adjusting device that has a better tightening effect and is convenient for adjusting the loosening of the rear hoop. Utility Model Content

[0006] The technical problem to be solved by the utility model is to overcome the defects in the prior art, thereby providing a rear hoop adjusting device.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A rear hoop adjustment device is used to adjust the circumference of the rear hoop of a safety helmet, comprising a shell, a power unit for driving the rear hoop to tighten or loosen, and a locking unit for limiting the automatic loosening of the rear hoop, wherein the locking unit comprises a locking wheel fixedly arranged relative to the shell and a locking claw fixedly arranged relative to the power unit; the locking wheel has a plurality of groups of gear teeth distributed in an annular array, the number of teeth in each group of the gear teeth is equal to the number of teeth in the locking claw, and each group of the gear teeth has a high tooth and a plurality of low teeth, so that after the locking claw rotates one tooth position, only one of the locking claws and one of the high teeth is pressed against the limit position.

[0009] Preferably, the locking wheel comprises a ring plate and a bottom plate which are fixedly connected; the gear teeth are arranged on the inner wall surface of the ring plate; and the upper end of the power part passes through the bottom plate and is fixedly connected to the locking claw.

[0010] Preferably, a support portion for supporting the locking claw is provided on the upper end surface of the base plate; the support portion is distributed in a ring shape on the upper end surface, and at least one of the support portions is distributed around the periphery of the upper end of the power part.

[0011] Preferably, it further comprises a rotating cover tightly connected to the shell; a pressure plate is provided on the rotating cover, and the pressure plate presses against a side of the locking claw away from the supporting portion.

[0012] Preferably, it also includes a rotating cover, on which is provided a central shaft for driving the power unit to rotate; the central shaft penetrates the power unit along its central axis direction and is tightly pressed against the shell, and the central axis of the central shaft coincides with the central axis of the power unit; the outer wall surface of the central shaft is tightly pressed against the power unit.

[0013] Preferably, an engaging ring groove is provided on the shell; and the lower end of the power part extends into the engaging ring groove.

[0014] Preferably, the engaging annular groove has a first inclined conical surface; and the power part has a second inclined conical surface which is tightly matched with the first inclined conical surface.

[0015] Preferably, the lower end surface of the bottom plate is tightly pressed against the rear hoop for limiting position.

[0016] Preferably, the shell is provided with a mounting groove for the rear hoop to pass through; an opening is provided on one side of the mounting groove, the locking wheel is installed at the opening and is detachably connected to the shell; the locking wheel is provided with a plurality of abutting surfaces that are tightly abutted against the shell, and a plurality of the abutting surfaces are arranged at an angle.

[0017] Preferably, it also includes a protective support pad; the protective support pad is detachably connected to the shell.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] The above technical solution provides a rear hoop adjustment device, wherein the locking part includes a locking wheel and a locking claw, wherein the locking wheel has a plurality of groups of gear teeth, the number of teeth in each group of gear teeth is equal to the number of teeth in the locking claw, and each group of gear teeth is provided with high teeth and short teeth, so that after the locking claw rotates one tooth position, at most two locking claws and one high tooth are pressed against and limited, and the remaining locking claws and the short teeth are pressed against, so that the pressing and limiting effect of the rear hoop after adjustment is ensured by the cooperation of at most two locking claws and the high teeth, and at the same time, the cooperation of the remaining short teeth and the remaining locking claws can apply supporting force to the power unit in multiple directions through the locking claws, thereby increasing the stability of the power unit and avoiding deformation of the corresponding locking claw caused by excessive force on a single locking claw; in addition, it is ensured that most of the locking claws cooperate with the short teeth. When the power unit is reversed, the locking claws cooperating with the short teeth are more likely to disengage from the gear teeth, making it easier for the rear hoop to loosen. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of one implementation mode of the utility model.

[0022] Figure 2 for Figure 1 Exploded view of the center-rear hoop adjustment device.

[0023] Figure 3 for Figure 1 Schematic diagram of the cooperation between the locking wheel and the locking claw of the center-rear hoop adjustment device.

[0024] Figure 4 for Figure 3 A magnified schematic diagram of position A in the middle.

[0025] Figure 5 for Figure 2 Schematic diagram of the structure of the middle locking wheel.

[0026] Figure 6 for Figure 1 Schematic cross-section of the center rear hoop adjustment device.

[0027] Figure 7 for Figure 6 A magnified schematic diagram of position B in the middle.

[0028] Figure 8 for Figure 6 Enlarged schematic diagram of the C position in the middle.

[0029] Fig. 9 for Figure 2 Schematic diagram of the structure of the rotating cover.

[0030] Fig.10 for Figure 1 A schematic cross-sectional view of the middle and rear hoop adjustment device from another angle.

[0031] Marking Description:

[0032] 1. Shell; 11. Engaging ring groove; 111. First inclined cone surface; 12. Mounting groove; 13. Opening; 14. Boss; 15. Support plate; 16. Matching groove; 2. Power unit; 20. Second inclined cone surface; 21. Central rotating shaft; 211. Notch; 22. Driving gear; 3. Locking unit; 31. Locking wheel; 310. Gear; 3101. High teeth; 3102. Low teeth; 311. Ring plate; 312. Bottom plate; 312 0. Sinking guide groove; 3121. Upper end surface; 3122. Lower end surface; 313. Limit block; 314. Extension platform; 315. Buckle; 316. Support plate; 32. Locking claw; 321. Through hole; 4. Support part; 5. Rotating cover; 50. Rotating connector; 501. Drive block; 51. Pressure plate; 52. Through shaft; 53. Center shaft; 6. Protective support pad; 61. Mounting plate; 62. Special-shaped clamping piece; 10. Rear hoop. DETAILED DESCRIPTION

[0033] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] See also Figures 1 to 10 The embodiment of the utility model provides a rear hoop adjustment device for adjusting the circumference of the rear hoop 10 of the helmet, comprising a housing 1, a power unit 2 for driving the rear hoop 10 to tighten or loosen, and a locking unit 3 for limiting the automatic loosening of the rear hoop 10. The power unit 2 is used to drive the rear hoop 10 to tighten or loosen; the locking unit 3 is used to limit the automatic loosening of the rear hoop 10 and cause the circumference to change again when the rear hoop 10 is adjusted to a specified circumference.

[0037] The power unit 2 and the locking unit 3 can be set to a variety of structures, so that the power unit 2 can drive the rear hoop 10 to adjust the circumference, and the locking unit 3 can limit the automatic change of the circumference of the rear hoop 10 after the power unit 2 adjusts the circumference of the rear hoop 10.

[0038] See also Figures 2 to 4 In order to ensure the locking wheel 31 and the locking claw 32 to have a tight and limiting effect while facilitating the loosening adjustment of the rear hoop 10, in this embodiment, the locking part 3 includes a locking wheel 31 fixedly arranged relative to the housing 1 and a locking claw 32 fixedly arranged relative to the power part 2. Among them, the locking wheel 31 has a plurality of groups of gear teeth 310 distributed in an annular array, and the number of teeth of each group of gear teeth 310 is equal to the number of teeth of the locking claw 32. Each group of gear teeth 310 has a high tooth 3101 and a plurality of low teeth 3102, so that after the locking claw 32 rotates one tooth position, at most two locking claws 32 and one high tooth 3101 are pressed and limited. The cooperation of at most two locking claws 32 and the high teeth 3101 ensures the tight and limiting effect of the rear hoop 10 after adjustment. At the same time, the cooperation between the remaining short teeth 3102 and the remaining locking claws 32 can apply supporting forces in multiple directions to the power unit 2 through the locking claws 32, thereby increasing the stability of the power unit 2 and avoiding deformation of the corresponding locking claw 32 caused by excessive force on a single locking claw 32; in addition, it is ensured that most of the locking claws 32 cooperate with the short teeth 3102. When the power unit 2 is reversed, the locking claws 32 cooperating with the short teeth 3102 are more likely to disengage from the gear teeth 310, making it easier for the rear hoop 10 to loosen.

[0039] It is worth noting that the "fixed setting" referred to above can be fixed by an integral molding method, or by fasteners such as buckles and screws. In this embodiment, the locking wheel 31 is fixed to the housing 1 in a detachable mounting manner, so that the locking wheel 31 can be removed and replaced, and the locking claw 32 is integrally formed with the power unit 2, so that the two can maintain synchronous movement.

[0040] Specifically, in this embodiment, three locking claws 32 are provided, and eleven groups of gear teeth 310 of the locking wheel 31 are provided, that is, the total number of gear teeth 310 is thirty-three. Figure 3 and Figure 4 For the convenience of explanation, the three locking claws 32 are defined as A1, A2 and A3, and A1, A2 and A3 are arranged in sequence in the counterclockwise direction. The high teeth 3101, the first short teeth 3102 and the second short teeth 3102 of each group of gear teeth 310 are defined as H, S1 and S2, respectively, and H, S1 and S2 of the same group of gear teeth 310 are arranged in sequence in the clockwise direction. A1, A2 and A3 are respectively pressed against different groups of gear teeth 310 for limiting positions, wherein A1 is pressed against H, A2 is pressed against S1, and A3 is pressed against S2. When the power unit 2 rotates one tooth position clockwise, A1 is pressed against S1 of the corresponding group (i.e. S1 of the same group as H with which it starts to press), A2 is pressed against S2 of the corresponding group (i.e. S2 of the same group as S1 with which it starts to press), and A3 is pressed against H of the next group (i.e. H of the next group adjacent to S2 with which it starts to press). When the power unit 2 rotates one tooth position again, the cycle is repeated in sequence to ensure that at least one locking claw 32 is pressed against the high tooth 3101 (i.e. H). It is worth mentioning that in this embodiment, three locking claws 32 are set and eleven groups of gear teeth 310 of the locking wheel 31 are set as an example for explanation, but the number of locking claws 32 and the number of teeth of the gear teeth 310 of the locking wheel 31 are not limited to ensure that they can be circulated, and at most two locking claws 32 (preferably one) are pressed against the high teeth 3101. The specific number and multiple relationship of the number of locking claws 32 and the number of teeth 310 of the locking wheel 31 can be set according to needs. When the number of teeth 310 is more, the adjustment accuracy of the rear hoop 10 is also higher.

[0041] In order to reduce the weight of the helmet, the rear hoop adjustment device of the helmet is made of injection molded parts. In order to facilitate the tightness adjustment of the rear hoop 10, the gear teeth 310 of the locking wheel 31 in this embodiment are usually provided with high teeth 3101 and short teeth 3102. When the adjustment device is in use, a certain force will be generated between the locking claw 32 and the gear teeth 310, which will easily cause the wear of the gear teeth 310. In order to avoid the wear of the gear teeth 310 causing the entire adjustment device to be unusable, in this embodiment, a mounting groove 12 for the rear hoop 10 to pass through is provided on the shell 1; an opening 13 is provided on one side of the mounting groove 12, and the locking wheel 31 is installed at the opening 13 and is detachably connected to the shell 1; a plurality of abutting surfaces that are tightly abutted against the shell 1 are provided on the locking wheel 31, and the plurality of abutting surfaces are arranged at an angle. This arrangement, on the one hand, when the gear teeth 310 of the locking wheel 31 are worn, it is convenient to separately disassemble and replace the locking wheel 31, and on the other hand, the locking wheel 31 is pressed against the shell 1 through the plurality of abutting surfaces to ensure the stable installation of the locking wheel 31.

[0042] See also Figure 2 and Figure 5 In this embodiment, the locking wheel 31 includes a ring plate 311 and a bottom plate 312 that are fixedly connected; the gear teeth 310 are arranged on the inner wall surface of the ring plate 311. The abutting surface on the locking wheel 31 can be formed in various forms, and the abutting surface has multiple and angled settings, so that the locking wheel 31 is subjected to forces at multiple angles applied by the housing 1.

[0043] Specifically, in order to achieve circumferential limitation of the locking wheel 31 and prevent the locking wheel 31 from synchronously rotating circumferentially when the locking claw 32 rotates circumferentially, in the present embodiment, the locking wheel 31 also includes a limit block 313 fixed on the outer wall surface of the ring plate 311, and the limit block 313 is adapted to the opening 13. At this time, the side wall surface of the limit block 313 forms an abutment surface and abuts against the side wall surface of the opening 13 of the shell 1, and this abutment surface is parallel to the central axis of the power unit 2.

[0044] Furthermore, in order to reduce the processing and installation costs of the housing 1 and the locking wheel 31, the openings 13 in this embodiment are distributed in a rectangular shape, and the stopper 313 is adapted to the shape of the opening 13 so that the outer contour of the projection of the whole formed by the stopper 313 and the ring plate 311 in the axial direction coincides with the contour of the opening 13. Of course, in other embodiments, the opening 13 may also be triangular, polygonal or other irregular structures.

[0045] See also Figure 2 as well as Figures 5 to 7In order to form a position-limiting and tight contact with the locking wheel 31 in the axial direction, in this embodiment, a boss 14 is provided at the upper end of the housing 1 in the axial direction, and a plurality of extension platforms 314 corresponding to and tight against the boss 14 are provided on the circumferential side of the upper end of the ring plate 311 of the locking wheel 31. At the same time, four buckles 315 extending in the axial direction are provided at the lower end of the limit block 313. The side of the buckle 315 away from the ring plate 311 penetrates the housing 1 and abuts against the lower end of the housing 1, thereby abutting and limiting the axial direction of the locking wheel 31. It can be known that at this time, the surface of the extension platform 314 abutting against the housing 1 and the surface of the buckle 315 abutting against the housing 1 form a contact surface, and the contact surfaces are parallel to each other and perpendicular to the central axis of the power unit 2.

[0046] Furthermore, in order to further increase the stability of the installation of the locking wheel 31, in the present embodiment, the locking wheel 31 also includes a plurality of support plates 316 extending along the axial direction, and the support plates 316 and the buckles 315 are staggered to form a plurality of support points between the locking wheel 31 and the housing 1, thereby ensuring the stable installation of the locking wheel 31.

[0047] See also Figure 6 and Figure 7 In order to prevent the rear hoop 10 from deforming when subjected to force, in the present embodiment, one side of the rear hoop 10 cooperates with the power unit 2, and the other side wall surface corresponding to the power unit 2 abuts against the side wall surface of the support plate 316, thereby radially limiting the rear hoop 10; at the same time, one of the two axially opposite wall surfaces of the rear hoop 10 abuts against the shell body 1, and the other abuts against the lower end surface 3122 of the bottom plate 312, thereby limiting the rear hoop 10 axially.

[0048] The power unit 2 may also adopt a variety of structures, as long as it can achieve the tightness adjustment of the rear hoop 10. In this embodiment, the power unit 2 adjusts the rear hoop 10 in a manner that a gear and a rack are meshed.

[0049] Specifically, see Figure 2 , Figure 6 , Figure 7 and Figure 8 The power unit 2 includes a central shaft 21 and a driving gear 22. In order to limit the power unit 2 and prevent the power unit 2 from shaking or shifting during operation, in this embodiment, the central shaft 21 passes through the bottom plate 312 and is fixedly connected to the locking claw 32, and the driving gear 22 passes through the bottom plate 312 and is fixedly connected to the central shaft 21, so that the locking claw 32 and the driving gear 22 can move synchronously, and at the same time, the bottom plate 312 can also press against the upper end of the driving gear 22 to limit the position.

[0050] Furthermore, in order to further achieve the limitation of the lower end of the power unit 2, an interlocking annular groove 11 is provided on the shell 1, and the lower end of the driving gear 22 of the power unit 2 extends into the interlocking annular groove 11, so that the side wall of the interlocking annular groove 11 can be abutted against the driving gear 22 without affecting the rotation of the driving gear 22, thereby further achieving the circumferential limitation of the driving gear 22.

[0051] Furthermore, in order to facilitate the installation of the power unit 2 and generate multi-directional abutment force between the power unit 2 and the shell 1, in this embodiment, the engaging ring groove 11 has a first inclined conical surface 111; the power unit 2 has a second inclined conical surface 20 that is tightly matched with the first inclined conical surface 111.

[0052] It is worth noting that when the driving structure of the power unit 2 is set as the driving gear 22, correspondingly, in order to achieve the adjustment of the rear hoop 10, the rear hoop 10 is set in pairs, and each rear hoop 10 has a rack meshing with the driving gear 22 for transmission. When the driving gear 22 rotates clockwise, it meshes with the two racks for transmission, thereby driving the two rear hoops 10 to move toward each other to tighten the circumference. When the circumference is adjusted to the specified circumference, the locking claw 32 can engage with the gear teeth 31 of the locking wheel 31. 0 is engaged and limited, which limits the automatic loosening of the rear hoop 10. When the driving gear 22 rotates counterclockwise, it meshes with the two racks for transmission, thereby driving the two rear hoops 10 to move away from each other to tighten the circumference. Since the locking claw 32 is an injection molded part, it has a certain flexibility and can produce a certain deformation under the action of external force, so that the locking claw 32 is disengaged from the gear teeth 310 (that is, the arc surface of the locking claw 32 is in contact with the gear teeth 310), which will not limit the movement of the rear hoops 10 away from each other, thereby realizing the circumference adjustment of the rear hoop 10.

[0053] Since the friction between the locking wheel 31 and the locking claw 32 will affect the smooth operation of both, and easily affect the service life of both, Figure 2 , Figures 6 to 9 In this embodiment, a support portion 4 for supporting the locking claw 32 is provided on the upper end surface 3121 of the bottom plate 312, thereby reducing the contact area between the bottom plate 312 and the locking claw 32 and reducing the friction. The reduction of friction, on the one hand, can reduce the force applied by the operator to the adjustment device, which is convenient for driving the adjustment of the rear hoop 10, and at the same time can reduce the probability of deformation of the locking claw 32 and the locking wheel 31. On the other hand, the reduction of friction can also reduce frictional heat generation, further reducing the probability of deformation between the locking claw 32 and the locking wheel 31, so as to increase the service life of the locking claw 32 and the locking wheel 31 and ensure the stable operation between the locking claw 32 and the locking wheel 31.

[0054] Specifically, the support portion 4 is distributed on the upper end surface 3121 in an annular shape, and at least one support portion 4 is distributed around the periphery of the upper end of the power portion 2 to further enhance the tightening effect on the driving gear 22 .

[0055] Furthermore, in order to increase the supporting effect of the supporting portion 4 to a certain extent and avoid an excessively large supporting area, the supporting portion 4 is distributed in an annular shape on the upper end surface 3121, and one end of the supporting portion 4 that contacts the locking claw 32 has a chamfer. Of course, in other embodiments, the supporting portion 4 may also be distributed in a block or columnar shape, as long as a stable support for the locking claw 32 can be achieved.

[0056] Furthermore, in order to limit the locking claw 32 along the axial direction, the present embodiment further includes a rotating cover 5, which covers the locking claw 32 and the locking wheel 31. The rotating cover 5 is provided with a pressure plate 51, which presses against the side of the locking claw 32 away from the support portion 4.

[0057] Furthermore, a through shaft 52 is further provided on the rotating cover 5, and the through shaft 52 passes through a through hole 321 provided on the locking claw 32, and abuts against the bottom surface of the sunken guide groove 3120 provided on the upper end surface 3121 of the bottom plate 312, so that the rotation of the rotating cover 5 drives the locking claw 32 to rotate synchronously and deform to disengage from the gear teeth 310. At the same time, the through shaft 52 can abut against the locking claw 32 through the through hole 321, limit the locking claw 32, and prevent the locking claw 32 from being excessively stressed and deformed.

[0058] See also Figure 2 as well as Fig. 9 and Fig.10 In order to facilitate the operation of the driving power unit 2, in the present embodiment, the rotating cover 5 is tightly connected to the housing 1, and a rotating connector 50 is fixed on the rotating cover 5, which is then connected to the power unit 2 through the rotating connector 50, so that the power of the rotating cover 5 can be transmitted to the power unit 2 to drive the power unit 2 to rotate.

[0059] Specifically, the rotating connector 50 includes a driving block 501 fixedly connected to the rotating cover 5 , and the driving block 501 abuts against a notch 211 provided on the central rotating shaft 21 , thereby realizing power transmission.

[0060] Furthermore, in order to achieve stable installation of the rotating cover 5, a central shaft 53 is provided on the rotating cover 5; the central shaft 53 penetrates the power part 2 along the central axis direction of the power part 2, and is pressed against the housing 1, and the central axis of the central shaft 53 coincides with the central axis of the power part 2; the outer wall surface of the central shaft 53 is pressed against the power part 2. The central shaft 53 penetrates the power part 2, and the outer wall surface of the central shaft 53 can be pressed against the power part 2, so that the central shaft 53 can further limit the power part 2, which is conducive to the stable operation of the power part 2.

[0061] Furthermore, since the shell 1 needs to be structurally installed, it has a certain hardness. In order to prevent the shell 1 from being too hard and affecting user use, the present embodiment also includes a protective support pad 6, which is detachably connected to the shell 1.

[0062] Specifically, see Figure 2 and Fig.10 In this embodiment, the protective support pad 6 has mounting plates 61 at both ends, and the mounting plates 61 have special-shaped clamping members 62 at both ends, wherein the mounting plates 61 abut against the supporting plates 15 on the shell 1, and the special-shaped clamping members 62 abut against the matching grooves 16 on the shell 1.

[0063] It is worth noting that, in this embodiment, "axial" refers to the central axis direction of the rotation center of the power unit 2, "upper end" refers to the side close to the rotating cover 5, and correspondingly, "lower end" refers to the side close to the protective support pad 6.

[0064] The above-mentioned implementation modes are only preferred implementation modes of the present invention, and cannot be used to limit the protection scope of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A rear hoop adjusting device, used for adjusting the circumference of the rear hoop of a helmet, comprising a housing, a power unit for driving the rear hoop to tighten or loosen, and a locking unit for limiting the rear hoop from automatically loosening, characterized in that: The locking part comprises a locking wheel fixedly arranged relative to the housing and a locking claw fixedly arranged relative to the power part; The locking wheel has a plurality of groups of gear teeth distributed in a circular array, the number of teeth in each group of gear teeth is equal to the number of teeth in the locking claw, and each group of gear teeth has a high tooth and a plurality of low teeth, so that after the locking claw rotates one tooth position, at most two locking claws and one high tooth are pressed against the limit position.

2. A rear hoop adjustment device according to claim 1, characterized in that: The locking wheel comprises a ring plate and a bottom plate which are fixedly connected; The gear teeth are arranged on the inner wall surface of the ring plate; The upper end of the power part passes through the bottom plate and is fixedly connected to the locking claw.

3. A rear hoop adjustment device according to claim 2, characterized in that: A supporting portion for supporting the locking claw is provided on the upper end surface of the bottom plate; The support parts are distributed on the upper end surface in an annular shape, and at least one of the support parts is distributed around the periphery of the upper end of the power part.

4. A rear hoop adjustment device according to claim 3, characterized in that: Also includes a rotating cover tightly connected to the shell; The rotating cover is provided with a pressing plate, and the pressing plate presses against a side of the locking claw away from the supporting portion.

5. A rear hoop adjustment device according to claim 2, characterized in that: It also includes a rotating cover, on which a central shaft for driving the power unit to rotate is provided; The central shaft passes through the power part along the direction of its central axis and is tightly abutted against the shell, and the central axis of the central shaft coincides with the central axis of the power part; The outer wall surface of the central axis is tightly pressed against the power part.

6. A rear hoop adjustment device according to claim 5, characterized in that: The housing is provided with an engaging annular groove; The lower end of the power part extends into the embedded annular groove.

7. A rear hoop adjustment device according to claim 6, characterized in that: The engaging annular groove has a first inclined conical surface; The power part has a second inclined conical surface which is tightly matched with the first inclined conical surface.

8. The rear hoop adjustment device according to claim 2, characterized in that: The lower end surface of the bottom plate is tightly pressed against the rear hoop to limit position.

9. A rear hoop adjustment device according to claim 1, characterized in that: The shell is provided with a mounting groove for the rear hoop to pass through; An opening is provided on one side of the installation groove, and the locking wheel is installed at the opening and is detachably connected to the housing; The locking wheel is provided with a plurality of abutting surfaces which are tightly abutted against the shell, and the plurality of abutting surfaces are arranged at an angle.

10. The rear hoop adjustment device according to claim 1, characterized in that: Also included are protective support pads; The protective support pad is detachably connected to the shell.

Images