A RATCHET STRUCTURE

Abstract

 A ratchet structure (100) is provided. The ratchet structure comprises a housing (102) having at least one pair of racks (108) slidably overlapped with each other. Further, a cover (104) coupled to the housing, having a cavity (124). Further, a ratchet gear (130) detachably secured within the cavity, and comprising a plurality of elastic ribs (134) having one or more grooves (140). Further, a knob (106) having a plurality of driving ribs (304) configured to be received within the one or more grooves of the plurality of elastic ribs. Therefore, the plurality of driving ribs facilitates the movement of the plurality of elastic ribs of the ratchet gear to slide the at least one pair of racks.

Description

FIELD OF THE DISCLOSURE

[0001] The present invention relates to a safety ratchet. More particularly, the invention relates to a helmet ratchet structure.

BACKGROUND OF THE DISCLOSURE

[0002] Protective gears such as safety helmets, body protectors, and many other products are provided with fasteners that are used to couple these products with other objects. Specifically, the safety helmets are used at constructions sites that need to be secured on a user's head. When the safety helmets are used, they are required to withstand continuous movement. In order to secure the safety helmets multiple straps are required to be fastened with the safety helmets. Such straps use buckle to fasten the straps of the helmet. However, these straps are not capable of withstanding continuous movement of the helmet. Further, these straps usually dislocate the helmet by accidental or unintentional readjustment. Typically, different ratchets are used to fasten the helmet over the head. However, these ratchets do not provide easy readjustment options to the user and do not prevent unintentional readjustment of the straps and helmet.

SUMMARY OF THE DISCLOSURE

[0003] The following presents a simplified summary in order to provide a basic understanding of some aspects of the present disclosure. This summary is not an extensive overview and is intended to neither identify key or critical elements nor delineate the scope of such elements. Its purpose is to present some concepts of the described features in a simplified form as a prelude to the more detailed description that is presented later.

[0004] In an example embodiment, a ratchet structure is provided. The ratchet structure comprises a housing having at least one pair of racks slidably overlapped with each other. Further, a cover coupled to the housing, having a cavity. Further, a ratchet gear detachably secured within the cavity. The ratchet gear comprising a plurality of elastic ribs having one or more grooves. Further, a knob having a plurality of driving ribs configured to be received within the one or more grooves of the plurality of elastic ribs. Thereafter, the plurality of driving ribs facilitates the movement of the plurality of elastic ribs of the ratchet gear to slide the at least one pair of racks.

[0005] In some embodiments, a rod is attached to the housing that radially extends through the cover and the ratchet gear.

[0006] In some embodiments, the cavity is fabricated with a first set of snaps and the ratchet gear is fabricated with a second set of snaps. In some embodiments, the first set of snaps engages with the plurality of elastic ribs and the second set of snaps engages with the at least one pair of racks, for the adjustment of the ratchet gear.

[0007] In some embodiments, the first set of snaps engages with the second set of snaps to interlock with each other and restrict movement of the ratchet gear, that in turn locks the movement of the at least one pair of racks.

[0008] In some embodiments, the at least one pair of racks is fabricated with a notched track that engages with the second set of snaps for the adjustment of the ratchet gear.

[0009] In some embodiments, the plurality of elastic ribs is fabricated with at least one protruded section that deforms while making contact with the second set of snaps of the ratchet gear.

[0010] In some embodiments, the knob includes one or more recess for proper holding of the knob. In some embodiments, the knob includes a plurality of clips configured to couple the knob to the cover.

[0011] In some embodiments, the ratchet gear having at least one location column, for providing support to the plurality of elastic ribs.

[0012] In another example embodiment, a helmet ratchet structure is provided. The helmet ratchet structure comprises a housing attached to a helmet via at least one pair of racks slidably overlapped with each other. Further, a cover coupled to the housing, having a cavity fabricated with a first set of snaps. Further, a ratchet gear detachably secured within the cavity, and comprising a second set of snaps and a plurality of elastic ribs with one or more grooves. Further, a knob having a plurality of driving ribs configured to be received within the one or more grooves. The plurality of driving ribs facilitates movement of the plurality of elastic ribs of the ratchet gear to slide the at least one pair of racks and the second set of snaps engages with the first set of snaps, to restrict movement of the ratchet gear, that in turn locks the movement of the at least one pair of racks to fasten the helmet.

[0013] The above summary is provided merely for purposes of summarizing some example embodiments to provide a basic understanding of some aspects of the invention. Accordingly, it will be appreciated that the above-described embodiments are merely examples and should not be construed to narrow the scope or spirit of the invention in any way. It will be appreciated that the scope of the invention encompasses many potential embodiments in addition to those here summarized, some of which will be further described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Having thus described certain example embodiments of the present disclosure in general terms, reference will hereinafter be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1A illustrates a front view of a ratchet structure, in accordance with the present disclosure;

FIG. 1B illustrates an exploded view of the ratchet structure, in accordance with the present disclosure;

FIG. 2A illustrates the front view of the ratchet structure having a ratchet gear coupled to at least one pair of racks, in accordance with the present disclosure;

FIG. 2B illustrates a perspective view of the ratchet structure with a cover, in accordance with the present disclosure;

FIG. 2C illustrates an isometric view of the ratchet gear, in accordance with the present disclosure;

FIG. 3A illustrates another perspective view of the ratchet structure with the knob detachably coupled to the cover and the ratchet gear, in accordance with the present disclosure;

FIG. 3B illustrates a top view of the knob mounted over the ratchet gear, in accordance with the present disclosure;

FIGS. 3C-3D illustrate a sectional view of the ratchet structure, in accordance with the present disclosure;

FIG. 3E illustrates another perspective view of the ratchet structure with the ratchet gear coupled to the at least one pair of racks, in accordance with the present disclosure;

FIG. 4A illustrates the ratchet structure with the knob rotated in a clockwise direction, in accordance with the present disclosure;

FIG. 4B illustrates the ratchet structure with the knob rotated in an anticlockwise direction, in accordance with the present disclosure;

FIG. 4C illustrate extension and retraction movement of at least one pair of racks, in accordance with the present disclosure;

FIG. 5 illustrates the ratchet structure in a locked state, in accordance with the present disclosure;

FIG. 6A illustrates a top view of a ratchet structure, in accordance with another embodiment of the present disclosure;

FIG. 6B illustrates a front view of the ratchet structure, in accordance with another embodiment of the present disclosure;

FIG. 6C illustrates a side view of the ratchet structure, in accordance with another embodiment of the present disclosure;

FIG. 6D illustrates a backside view of the ratchet structure, in accordance with another embodiment of the present disclosure;

FIG. 6E illustrates an exploded view of the ratchet structure, in accordance with another embodiment of the present disclosure; and

FIG. 7 illustrates a side view of a helmet coupled to the ratchet structure, in accordance with the present disclosure.

DETAILED DESCRIPTION

[0015] The exemplary embodiments described herein provide detail for illustrative purposes and are subject to many variations in structure and design. It should be appreciated, however, that the embodiments are not limited to a particularly disclosed embodiment shown or described. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the claims.

[0016] Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The terms "a," "an," and "the" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced object. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Like numerals represent like parts in the figures.

[0017] Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings in which like numerals represent like elements throughout the several figures, and in which example embodiments are shown. Embodiments of the present disclosure may, however, be embodied in alternative forms and should not be construed as being limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples.

[0018] Various embodiments of the present disclosure disclose a ratchet structure for safety helmets. In some embodiments, the present disclosure discloses that the ratchet structure may be coupled to a rear side of a helmet. The ratchet structure may employ a strap with an adjustment mechanism, to loosen or tighten the ratchet structure with the helmet. Further, a user may adjust tightening and loosening of his/her helmet with ease without removing the helmet from his/her head.

[0019] FIG. 1A illustrates a front view of a ratchet structure 100, in accordance with the present disclosure. FIG. 1A is described in conjunction with FIG. 1B.

[0020] In some embodiments, the ratchet structure 100 may be equipped over a helmet (not shown) to fasten or unfasten the helmet over a head of a user. The ratchet structure 100 may be coupled with one or more straps (not shown) of the helmet, which may be tightened or loosened as per user convenience. Further, the ratchet structure 100 may be configured to fix the position of the one or more straps such that the helmet equipped over the head of the user does not get loose during a sudden movement of the helmet.

[0021] The ratchet structure 100 may comprise a housing 102, a cover 104, and a knob 106. The housing 102 may be a hollow structure that creates a space for incorporating at least one pair of racks 108. The at least one pair of racks 108 may be incorporated within the housing 102 such that in some instances the at least one pair of racks 108 may extend outside from both ends 110 of the housing 102. In some embodiments, the at least one pair of racks 108 may be retracted inside the housing 102 from each end 110. The at least one pair of racks 108 may slide inside the housing 102 in a manner that the at least one pair of racks 108 may partially overlap with each other. In some embodiments, each end 112 of the at least one pair of racks 108 may be attached to the straps of the helmet. The extension and retraction of the at least one pair of racks 108 may stretch or release the strap of the helmet. The detailed movement of the at least one pair of racks 108 may be described in conjunction with FIGS. 2A-3E.

[0022] Further, the housing 102 may be detachably coupled to the cover 104. In some embodiments, the dimensions of the cover 104 may be marginally small in comparison to the dimensions of the housing 102. The difference in the dimensions may allow the cover 104 to snugly fit inside the housing 102. In some embodiments, the cover 104 may be coupled to the knob 106. The knob 106 may be configured to be rotated in clockwise direction or anticlockwise direction by the user. Further, the knob 106 may be fabricated with one or more recess 114. The one or more recess 114 may allow the user to properly grip the knob 106 by placing fingers in between the one or more recess 114. In some example embodiments, the knob 106 may be rotated in the clockwise direction or the anticlockwise direction to move the at least one pair of racks 108 inside or outside the housing 102 that will be described in greater detail in FIGS. 4A-4C. In some embodiments, the ratchet structure 100 may produce clicking sound during the clockwise rotation of the knob 106, that indicates the tightening of the helmet.

[0023] Further, the cover 104 may be fabricated with at least one clasp 116, as shown in FIG. 1B. In some embodiments, the at least one clasp 116 may be structured with a pocket 118. The pocket 118 fabricated in the at least one clasp 116, may create an empty space. In some embodiments, the empty space of the pocket 118 may allow the at least one clasp 116 to embody at least one bar 120 of the housing 102, that may detachably couple the cover 104 to the housing 102. Further, the housing 102 may be installed with a rod 122. The rod 122 may radially extend outside the housing 102. In some embodiments, the rod 122 may act as a pivoting point to rotate the knob 106 in the clockwise and/or anticlockwise direction.

[0024] Further, the cover 104 may be fabricated with a cavity 124. In some embodiments, the cavity 124 may be fabricated with a track 126. It may be noted that cavity 124 may be termed as an annular section. In some example embodiments, the track 126 may correspond to a circular protruded section integrated around the periphery of the cavity 124. Further, the track 126 may be coupled to a plurality of clips (not shown) fabricated with the knob 106. Such coupling of the track 126 with the plurality of clips allows the cover 104 to be attached with the knob 106 and provide a guided path for the rotation of the knob 106 in the clockwise or anticlockwise directions. In some embodiments, the cavity 124 may be of varied diameter. Further, the cavity 124 may be fabricated with a first set of snaps 128. In some embodiments, the first set of snaps 128 may be fabricated with a plurality of gear teeth. Further, the cavity 124 of the cover 104 may be configured to house a ratchet gear 130. The ratchet gear 130 may be configured to rotate in the clockwise direction or in the anticlockwise direction along the movement of the knob 106. The ratchet gear 130 may comprise a second set of snaps 132, a plurality of elastic ribs 134, and at least one location column 136. The second set of snaps 132 and the plurality of elastic ribs 134 may be fabricated on opposite faces of the ratchet gear 130. The detailed working of the second set of snaps 132, the plurality of elastic ribs 134, and the at least one location column 136, may be further described in FIGS. 2A-3E.

[0025] Further, the ratchet gear 130 may be fabricated with a hole 138. The hole 138 may allow the rod 122 to radially extend through the cover 104 and the ratchet gear 130. Further, the plurality of elastic ribs 134 may be fabricated with one or more grooves 140 that may be described in greater details in FIGS. 3A-3E. It will be apparent to one skilled in the art that above-mentioned components of the ratchet structure 100 have been provided only for illustration purposes, without departing from the scope of the disclosure.

[0026] FIG. 2A illustrates a front view of the ratchet structure 100 having the ratchet gear 130 coupled to the at least one pair of racks 108, in accordance with the present disclosure. FIG. 2A is described in conjunction with FIGS. 2B-2C.

[0027] In some embodiments, the at least one pair of racks 108 may be fabricated with a plurality of teeth 202. It may be noted that the plurality of teeth 202 may also be termed as a notched track. The plurality of teeth 202 may be fabricated to each of the at least one pair of racks 108 such the plurality of teeth 202 of each of the at least one pair of racks 108 may be positioned parallel with a space between the at least one pair of racks 108. Such space may allow to position the second set of snaps 132 of the ratchet gear 130 between the at least one pair of racks 108 and the plurality of teeth 202. The interlinkage between the at least one pair of racks 108 and the second set of snaps 132 may allow to convert the rotational movement of the ratchet gear 130 into linear movement carried by the at least one pair of racks 108. In some embodiments, the clockwise rotation of the ratchet gear 130 may facilitate the at least one pair of racks 108 to retract inside the housing 102. In some embodiments, the anticlockwise rotation of the ratchet gear 130 may facilitate the at least one pair of racks 108 to extend outside the housing 102.

[0028] In some embodiments, the plurality of elastic ribs 134 may further be fabricated with a protruded section 204, as shown in FIG. 2C. The interlinkage of the plurality of teeth 202 with the second set of snaps 132 may allow the plurality of protruded section 204 of the plurality of elastic ribs 134 to coincide with the first set of snaps 128, as shown in FIG. 2B. During the rotational movement of the ratchet gear 130, the protruded section 204 of the elastic ribs 134 periodically collides with the second set of snaps 132 that deforms the protruded section 204. The deformed protruded section 204 further rotates and collides with the second set of snaps 132, and thereby generates the clicking sound which indicates tightening of the ratchet structure 100 with the helmet.

[0029] FIG. 3A illustrates a perspective view of the ratchet structure 100 with the knob 106 detached from the cover 104 and the ratchet gear 130, in accordance with the present disclosure. FIG. 3A is described in conjunction with FIGS. 3B-3C.

[0030] In some embodiments, the knob 106 may be fabricated with a plurality of clips 302. The plurality of clips 302 may be fabricated at one side of the knob 106 to interlock with the track 126 fabricated around the cavity 124, as shown in FIG. 3B. The interlinkage of the plurality of clips 302 with the track 126 may allow the knob 106 to couple with the cover 104. In some embodiments, the plurality of clips 302 and the track 126 may also provide a smooth rotational movement to the knob 106 with respect to the cover 104.

[0031] In some embodiments, the knob 106 may be fabricated with a plurality of driving ribs 304. The plurality of driving ribs 304 may be protruded portions that may be inserted within the one or more grooves 140 of the plurality of elastic ribs 134 when the knob 106 is coupled to the cover 104, as shown in FIG. 3C. The plurality of driving ribs 304 once inserted inside the one or more grooves 140 of the plurality of elastic ribs 134, may facilitate the rotational movement of the knob 106, and thus results in the rotational movement of the ratchet gear 130. Once the knob 106 is coupled to the cover 104, the plurality of driving ribs 304 may push the plurality of elastic ribs 134. The force thus exerted by the plurality of driving ribs 304 over the plurality of elastic ribs 134 may result in the rotational movement of the ratchet gear 130.

[0032] FIGS. 4A-4B illustrate the ratchet structure 100 with the knob 106 rotated in clockwise rotation 402 and anticlockwise rotation 404, in accordance with the present disclosure. FIGS. 4A-4B are described in conjunction with FIG. 4C.

[0033] In some embodiments, the clockwise rotation 402 of the knob 106 may rotate the ratchet gear 130 that further retracts the at least one pair of racks 108 inside the housing 102. Once the knob 106 is rotated by the user in the clockwise rotation 402, by gripping the one or more recess 114, the plurality of driving ribs 304 may push the plurality of elastic ribs 134 in the clockwise rotation 402. Further, the protruded section 204 may engage with the first set of snaps 128 by the rotational movement of the plurality of elastic ribs 134. Such engagement of the protruded section 204 with the first set of snaps 128 may produce the clicking sound, as described earlier. Further, the rotational movement of the ratchet gear 130 may facilitate the rotational movement of the second set of snaps 132. The engagement of the second set of snaps 132 with the plurality of teeth 202, may further retract the at least one pair of racks 108 inside the housing 102, as shown by an arrow 406 in FIG. 4C.

[0034] In some embodiments, the anticlockwise rotation 404 of the knob 106 may rotate the ratchet gear 130 that in turn extends the at least one pair of racks 108 outside the housing 102. Once the knob 106 is rotated by the user in the anticlockwise rotation 404 by gripping the one or recess 114, the plurality of driving ribs 304 may push the plurality of elastic ribs 134 in the anticlockwise rotation 404. Further, the protruded section 204 may thereby engage with the first set of snaps 128 by the rotational movement of the plurality of elastic ribs 134. Further, the rotational movement of the ratchet gear 130 may facilitate the rotational movement of the second set of snaps 132. Such engagement of the second set of snaps 132 with the plurality of teeth 202, may further extend the at least one pair of racks 108 outside the housing 102, as shown by another arrow 408 in FIG. 4C.

[0035] FIG. 5 illustrates the ratchet structure 100 in a locked state, in accordance with the present disclosure. FIG. 5 is described in conjunction with FIGS. 1A-4B.

[0036] In some embodiments, the ratchet structure 100 may be adapted to be switched to the locked state by the user once the at least one pair of racks 108 are to be locked in a desired position. The ratchet structure 100 may be switched to the locked state by pulling the knob 106 by the user. Once the knob 106 may be pulled, the ratchet gear 130 partially slides outside through the cavity 124 along the knob 106. The sliding movement of the ratchet gear 130 results in disengaging the interlocking between the second set of snaps 132 from the plurality of teeth 202 of the at least one pair of racks 108. Similarly, the plurality of elastic ribs 134 disengages from the first set of snaps 128, to allow the second set of snaps 132 to mesh with the first set of snaps 128. Such interlinkage of the first set of snaps 128 with the second set of snaps 132 locks the rotational movement of the ratchet gear 130 and thereby fixes the position of the at least one pair of racks 108. The locked state of the ratchet structure 100 prevents unnecessary or accidental movement of the straps attached to the at least one pair of racks 108 and thereby prevents loosening of the helmet equipped by the user.

[0037] FIG. 6A illustrates a front view of a ratchet structure 600, in accordance with another embodiment of the present disclosure. FIG. 6A is described in conjunction with FIGS. 6B-6E.

[0038] In some embodiments, the ratchet structure 600 may be configured with the housing 102, the cover 104 and the knob 106, as described earlier. Further, each end 112 of the at least one pair of racks 108 may be fabricated with at least one buckle 602. The at least one buckle 602 may be configured to couple each end 112 of the at least one pair of racks 108 with the strap of the helmet. The extension and retraction of the at least one pair of racks 108 may allow the at least one buckle 602 to stretch or release the straps and thereby tighten or loosen the helmet. It may be noted that the at least one buckle 602 may be fabricated in circular orientation, as shown in FIG. 6C. In some embodiments, the shape and size of the at least one buckle 602 may vary based on the usage. It will be apparent to a person skilled in the art that the at least one buckle 602 may not be limited to couple with the strap, it may be attached to any entity configured to be stretched or released along the movement of the at least one pair of racks 108.

[0039] In some embodiments, the one or more recess 114 of the knob 106 may be fabricated with a knurled pattern 604, as shown in FIGS. 6B-6D. The knurled pattern 604 may be a crisscross pattern that may be configured to provide additional grip to the user while holding the knob 106. The knurled pattern 604 may provide an abrasive surface in comparison to a smooth surface for the fingers of the user. The knurled pattern 604 may have indentations that restrict slippage of the fingers of the user. Such an improved grip may be especially useful in applications where the knob 106 may be frequently used in wet or oily conditions. Further, the knurled pattern 604 may also improve grip for the user while wearing gloves. In some example embodiments, the knurled pattern 604 may be fabricated in straight lines, crisscross lines, or angular lines.

[0040] It should be noted that above-mentioned components and their mechanism of operation for the ratchet structure 100 may be applicable for the ratchet structure 600 as well, without departing from the scope of the disclosure.

[0041] FIG. 7 illustrates a side view of a helmet 702 coupled to the ratchet structure 100, in accordance with the present disclosure. FIG. 7 is described in conjunction with FIGS. 1A-6E.

[0042] In some embodiments, the ratchet structure 100 may be coupled to at least one strap 704 of the helmet 702. The ratchet structure 100 may be configured to loosen or tighten the at least one strap 704 of the helmet 702. The tightening of the at least one strap 704 may allow the helmet 702 to be securely fastened over a head 706 of a user 708. In some embodiments, based on the size of the head 706, the user 708 may rotate the knob 106 of the ratchet structure 100 in clockwise or anticlockwise directions. Once the helmet 702 is comfortably secured over the head 706 of the user 708, the knob 106 may be rotated by the user 708. The rotation of the knob 106 may lock the ratchet structure 100. The locked state of the ratchet structure 100 may thereby restrict rotational movement of the knob 106 and the lateral movement of the at least one pair of racks 108. The restricted movement of the at least one pair of racks 108 may thereby lock the position of the at least one strap 704. It may be noted that the fixed position of the at least one strap 704 may help the user 708 to keep the helmet 702 fixed over the head 706 for a longer period of time. Further, the helmet 702 may not move laterally in case of movement of the user 708 and the head 706.

[0043] Such ratchet structure 100 may facilitate loosening and tightening of the helmet 702 as per the user 708 convenience. Such clockwise and anticlockwise rotation of the knob 106 with the knurled pattern 604 grip may provide an ease of use to loosen and tighten the ratchet structure 100. Therefore, a wearer may easily adjust the helmet 702 according to the working conditions.

[0044] It will be apparent to one skilled in the art that the above-mentioned ratchet structure 100 may be applicable to any design such as protective gears, fastening straps etc., without departing from the scope of the disclosure.

[0045] As will be appreciated by one skilled in the art, aspects of the present disclosure may be embodied as a system, method, or computer program product. Accordingly, aspects of various embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit," "module", "system" or "sub-system". In addition, aspects of the present disclosure may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.

[0046] The foregoing descriptions of specific embodiments have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain principles and practical applications thereof, and to thereby enable others skilled in the art to best utilize the various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the claims. The following claims are in no way intended to limit the scope of embodiments to the specific embodiments described herein.

Claims

1. A ratchet structure comprising:

a housing having at least one pair of racks slidably overlapped with each other;

a cover coupled to the housing, defining a cavity;

a ratchet gear detachably secured within the cavity, wherein the ratchet gear comprising a plurality of elastic ribs having one or more grooves; and

a knob having a plurality of driving ribs configured to be received within the one or more grooves of the plurality of elastic ribs,

wherein the plurality of driving ribs facilitates movement of the plurality of elastic ribs of the ratchet gear to slide the at least one pair of racks.

2. The ratchet structure of claim 1, wherein a rod is attached to the housing that radially extends through the cover and the ratchet gear.

3. The ratchet structure of claim 1, wherein the cavity is fabricated with a first set of snaps and the ratchet gear is fabricated with a second set of snaps.

4. The ratchet structure of claim 3, wherein the first set of snaps engages with the plurality of elastic ribs and the second set of snaps engages with the at least one pair of racks, for adjustment of the ratchet gear.

5. The ratchet structure of claim 3, wherein the first set of snaps engages with the second set of snaps to interlock with each other and restrict movement of the ratchet gear, that in turn locks the movement of the at least one pair of racks.

6. The ratchet structure of claim 3, wherein the at least one pair of racks is fabricated with a notched track that engages with the second set of snaps for adjustment of the ratchet gear.

7. The ratchet structure of claim 3, wherein the plurality of elastic ribs is fabricated with at least one protruded section that deforms while making contact with the second set of snaps of the ratchet gear.

8. The ratchet structure of claim 1, wherein the knob having one or more recess for proper holding of the knob.

9. The ratchet structure of claim 1, wherein the knob includes a plurality of clips configured to couple the knob to the cover.

10. The ratchet structure of claim 1, wherein the ratchet gear having at least one location column, for providing support to the plurality of elastic ribs.

11. A helmet ratchet structure comprising:

a housing attached to a helmet via at least one pair of racks slidably overlapped with each other;

a cover coupled to the housing, having a cavity fabricated with a first set of snaps;

a ratchet gear detachably secured within the cavity, wherein the ratchet gear comprising a second set of snaps and a plurality of elastic ribs with one or more grooves; and

a knob having a plurality of driving ribs configured to be received within the one or more grooves,

wherein the plurality of driving ribs facilitates movement of the plurality of elastic ribs of the ratchet gear to slide the at least one pair of racks and the second set of snaps engages with the first set of snaps, to restrict movement of the ratchet gear, that in turn locks the movement of the at least one pair of racks to fasten the helmet.

12. The helmet ratchet structure of claim 11, wherein a rod is attached to the housing that radially extends through the cover and the ratchet gear.

13. The helmet ratchet structure of claim 11, wherein the first set of snaps engages with the plurality of elastic ribs and the second set of snaps engages with the at least one pair of racks, for adjustment of the ratchet gear.

14. The helmet ratchet structure of claim 11, wherein the plurality of elastic ribs is fabricated with at least one protruded section that deforms while making contact with the second set of snaps of the ratchet gear.

15. The helmet ratchet structure of claim 11, wherein the knob includes a plurality of clips configured to couple the knob to the cover.

Drawing