Abstract:
The present invention relates to an air vent structure for an inner air discharge of a helmet adapted to protect a user&#39;s head when a user rides a motorcycle, and in particular to an air vent structure for a helmet which is capable of preventing a breath steam from forming in an inner surface of a shield by installing an air vent in lower both sides of a shield installed in a front side of a helmet and accurately adjusting an opening and closing degree of an air vent. It is a primary object of the present invention to provide an air vent structure for a helmet which is capable of discharging an inner air based on the flow of an air of an air vent by installing an air vent at both lower sides of a shield of a helmet, improving a structure of an air flow of an air vent and accurately adjusting the amount of flowing air, and it is possible to adjust the flowing amount of air based on a helmet user&#39;s condition and a state of an inner and outer side of a helmet for thereby implementing a pleasant state.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an air vent structure for an inner air discharge of a helmet adapted to protect a user&#39;s head when a user rides a motorcycle, and in particular to an air vent structure for a helmet which is capable of preventing a breath steam from forming in an inner surface of a shield by installing an air vent in lower both sides of a shield installed in a front side of a helmet and accurately adjusting an opening and closing degree of an air vent. 
     2. Description of the Background Art 
     Generally, when a person rides a two-wheeled vehicle, the person must wear a head protecting helmet for protecting a rider&#39;s head. In the case of a full face helmet which covers up to a jaw portion of a user, a front shield must be installed. 
     The above shield is capable of preventing any interference in a field of vision by a wind force which occurs when a vehicle runs in a certain direction and preventing a breathing difficulty and obtaining a warm keeping effect in the winter season. 
     However, since the conventional helmet having a shield does not have an air vent for discharging an inner air to the outside, there are the following problems. 
     Namely, when a shield is dropped down for thereby shielding a forward field of vision of the helmet, the shield is capable of preventing a wind which is flown in a running direction and overcoming a breathing problem. However, in the case that there is a big temperature difference between the inner side and outside of the helmet like in the winter season, a breath steam may be formed in an inner surface of the shield due to a user&#39;s breathing, so that the user&#39;s field of vision becomes bad. 
     In addition, in order to overcome the above problems, various air vent ways are developed for thereby discharging an inner air to the outside. As one of the ways, the applicant of the present invention filed a patent No. 10-0299319(hereinafter, it is referred to as Prior art). 
     As shown in FIGS. 1 and 2, there is prepared a helmet body  10  which has a padding  12  in the interior of the same and a shield  20  in a front opening portion  11 . At the both front sides of the helmet body  10 , a communicating hole  13  is formed in the padding  12 , and a groove  14  is formed in such a manner that the communication hole  13  is positioned in the center. 
     In addition, an air vent member  30  is installed in such a manner that the air vent member is closely fixed to the groove  14 , and one end of the same is fixed by an engaging shoulder portion  31 , and the other end of the same is engaged by an engaging unit  32 , and a cover portion  33  is formed thereon for thereby forming a communicating portion  34 . 
     According to the above described prior art, the air which flows from the front side to the side of the helmet body  10  flows along an inner side of the cover portion  33  of the air vent member  30 , namely, along the inner side of the communicating portion  34  for thereby sucking an inner air of the communication hole  13  and discharging the sucked air(based on Vernoulli&#39;s theorem for a fluid). 
     However, in the air vent structure of the above prior art, the air is guided to flow in an inner side of the cover portion of the air vent member. There is provided only an opening and closing portion for opening and closing the guide portion. Therefore, when discharging an inner air, the amount of the air discharged is not controlled. 
     In detail, the size of the communicating hole  13  and the cross sectional area of the communication portion  34  are fixed, namely, unchangeable, the amount of the air flowing along the communicating portion  34  is constant. Therefore, the amount of the inner air discharged through the communication hole  13  is constant. 
     In the case that the formation of the breath steam is increased in the shield, the discharging amount of the air is not increased. In addition, in the case that the formation of the breath steam is small, it is impossible to decrease the discharging amount of the air for keeping warm. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an air vent structure for a helmet which overcome the problems encountered in the conventional art. 
     It is another object of the present invention to provide an air vent structure for a helmet which is capable of discharging an inner air based on the flow of an air of an air vent by installing an air vent at both lower sides of a shield of a helmet, improving a structure of an air flow of an air vent and accurately adjusting the amount of flowing air, and it is possible to adjust the flowing amount of air based on a helmet user&#39;s condition and a state of an inner and outer side of a helmet for thereby implementing a pleasant state. 
     In order to achieve the above objects, there is provided an air vent for a helmet which includes a helmet body which includes a front opening portion, a shield installed in such a manner that the opening portion is openable, a pad provided in a whole inner surface, and a communicating hole which is formed at right and left sides of a jaw protection portion in a lower portion of the opening portion and communicates with the outside; a base member which is fixed in such a manner that an outer portion of the communicating hole of the helmet body is covered, and which includes a first air inlet hole formed in a front side of the helmet, a first air moving space portion formed from the first air inlet hole to a rear side, a second air inlet hole formed in such a manner that more air is flown into the first air moving space portion, and a plurality of first air outlet holes formed in a rear side of the air moving space portion; a door base member which is slidable on the base member in a forward and backward direction in a state that a first inward rim closely is contacted with an outer surface of the base member and the first air inlet hole is opened and closed by a first end portion opens during the sliding, and which includes a third air inlet hole formed in an inner side of a first end portion and a second air outlet hole formed in a rear side at a certain distance from the third air inlet hole; and a side door member which is slidable on the door base member in a forward and backward direction in a state that a second inward rim is closely contacted with an outer surface of the door base member and the second air inlet hole is opened and closed by a second end portion during the sliding, and which includes a second air moving space portion in a rear side. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become better understood with reference to the accompanying drawings which are given only by way of illustration and thus are not limitative of the present invention, wherein; 
     FIG. 1 is a perspective view illustrating the construction of a conventional helmet; 
     FIG. 2 is a cross sectional view illustrating the construction of a conventional helmet; 
     FIG. 3 is a side view illustrating a helmet having an air vent apparatus according to the present invention; 
     FIG. 4 is a front view illustrating an air vent portion of FIG. 3 according to the present invention; 
     FIG. 5 is a disassembled perspective view illustrating a structure of an air vent structure according to the present invention; 
     FIG. 6 is a front view and bottom view illustrating each element of FIG. according to the present invention; 
     FIG. 7 is a plan cross sectional view illustrating an installation state according to the present invention; 
     FIG. 8 is a cross sectional view taken along line B—B of FIG. 4 according to the present invention; 
     FIG. 9 is a cross sectional view taken along line A—A of FIG. 4 for explaining an operation of a first opening step according to the present invention; 
     FIG. 10 is a front view illustrating an air vent structure based on a first opening step of FIG. 9 according to the present invention; 
     FIG. 11 is a cross sectional view taken along line A—A of FIG. 4 for explaining an operation of a second opening step according to the present invention; and 
     FIG. 12 is a front view illustrating an air vent structure based on a second opening step of FIG. 11 according to the present invention. 
     &lt;Descriptions of reference numerals of major elements of the drawings&gt; 
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     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The construction and operation of the present invention will be described with reference to the accompanying drawings. 
     FIG. 3 is a side view illustrating a helmet having an air vent apparatus according to the present invention, FIG. 4 is a front view illustrating an air vent portion of FIG. 3 according to the present invention, and FIG. 5 is a disassembled perspective view illustrating a structure of an air vent structure according to the present invention. 
     As shown therein, the air vent structure for a helmet according to the present invention is installed in a helmet body  100  which includes a front opening portion  101 , a shield  200  adapted to opening and closing the opening portion, a pad  110  provided in all inner portions, and a communicating hole  103  which is formed in the left and right sides of a jaw protection portion  102  provided in a lower portion of the opening portion for thereby communicating with the outside. 
     In addition, the air vent according to the present invention installed in an outer portion of the communicating hole  103  includes a base member  130 , a door base member  140  and a side door member  150 . 
     The base member  130  which is fixed to cover an outer surrounding portion of the communicating hole  103  of the helmet body  100  includes a first air inlet hole  131  formed in a front side of the helmet, a first air moving space portion  132  which communicates from the first air inlet hole to rear side, a second air inlet hole  133  formed in such a manner that more air is flown into the first air moving space portion  132 , and a plurality of first air outlet holes  134  formed in a rear side of the air moving space portion. 
     The door base member  140  is slidably moved in a forward and backward direction in a state that a first inward rim  141  is closely contacted with an outer surface of the base member  130 , so that a first end portion  142  of the same opens and closes the first air inlet hole  131 . The door base member  140  includes a third air inlet hole  143  formed in the inner side of the first end portion, and a second air outlet hole  144  formed in a rear side at a certain distance from the third air inlet hole. 
     In addition, the side door member  150  is slidably moved in a forward and backward direction in a state that a second inward rim  151  is closely contacted with an outer surface of the door base member  140 , so that the second end portion  152  opens and doses the second air inlet hole  133 . A second air moving space portion  153  is formed in the rear side. 
     The assembling and sliding structure will be described with reference to FIGS. 5 through 7. 
     Namely, the door base member  140  is slidable on the base member  130  and includes at least a pair of first engaging protrusions  147  in the inner side surface of the same. The first engaging protrusion  147  is slidable in a forward and backward direction along the pair of the first guide holes  136  formed in the bottom of the base member  130 . 
     In addition, the side door member  150  is slidable on the door base member  140  and includes at least a pair of second engaging protrusions  155  in the inner side surface of the same. The second engaging protrusions  155  are slidable in a forward and backward direction along the pair of the second guide holes  148  formed in the bottom of the door base member  140 . 
     In particular, the door base member  140  and the side door member  150  are slidably opened and closed on the base member  130  and the door base member  140 , respectively, and have the multiple stop points. 
     Namely, the door base member  140  includes a first inward stopper protrusion  145  and a first elastic piece  145   a  adapted to generate al elastic force to the first stopper protrusion  145  and stops whenever the first stopper protrusion  145  contacts with more than at least three first grooves  135  arranged in an outer surface of the base member  130  in a sliding direction at a regular interval. 
     In addition, the side door member  150  includes more than at least three second grooves  154  arranged in an inner surface in a sliding direction at a regular interval and stops whenever the second grooves  154  formed in an outer surface of the door base member  140  contact with the second elastic piece  146   a  having the second stopper protrusion  146   
     The side door member  150  has a second protrusion  156  in a lower portion of the upper side engaging protrusion  155  in a horizontal direction for limiting a retraction of the first elastic piece  14   a  in a certain section, and the base member  130  has a first protrusion  137  on the first lower side guide hole  136  in a horizontal direction for limiting a retraction of the first elastic piece  146   a  in a certain section. 
     The operation of the present invention will be described as follows. 
     A pair of the first guide holes  136  is formed in the base member  130  in a longitudinal direction. An end portion of each of the pair of the first engaging protrusions  147  of the door base member  140  inserted therein is formed in a wedge engaging shoulder shape. Therefore, when the end portion of the same is pressed from the upper side, the end portion of the same is inserted through the first guide hole  136 . After the end portion of the same is inserted therein, the end portion of the same is not disconnected. 
     Since the second engaging protrusion  155  of the side door member  150  is also formed in a wedge engaging shoulder shape, when the second engaging protrusion  155  is inserted into the pair of the second guide holes  148  formed in the door base member  140  in the longitudinal direction, the second engaging protrusion  155  is not disconnected 
     In addition, the first stopper protrusion  145  formed in the first elastic piece  145   a  in the door base member  140  may be engaged by the plurality of the first grooves  135  formed in the base member  130  and may be stopped at the engaged positions when the door base member  140  slides on the vase member  130 . In addition, a retraction operation of the first elastic piece  145   a  may be limited by the second protrusion  156  formed in a lower portion of the upper side engaging protrusion  155  in the side door member  150  in a certain section. 
     The above construction is provided so that the door base member  140  is closed after the side door member  150  is closed. 
     In addition, the door base member  140  may be engaged by a plurality of second grooves  154  formed in the side door member  150  and may stop at the engaged positions when the side door member  150  slides on the door base member  140 . A retraction operation of the first elastic piece  146   a  may be limited by the first protrusion  137  formed on the first lower side guide hole  136  in the base member  130  in a certain section. 
     The above construction is provided so that the side door member  150  is opened after the door base member  140  is opened. 
     The state of use of the present invention will be described. 
     The opening and closing steps based on the air vent according to the present invention is formed of a first opening step in which only the door base member  140  is opened in a state that the side door member  150  is closed, and a second opening step in which the side door member  150  is opened in a state that the door base member  140  is opened. Each of first and second opening steps may have four sub-steps, respectively. 
     For example, when a discharge of the inner air is not needed based on a helmet user&#39;s judgement, the door base member  140  sliding in the base member  130  and the side door member  150  sliding in the door base member  140  are all forwardly moved and closed. 
     As shown in FIG. 7, the second end portion  152  of the side door member  150  blocks the third air inlet hole  143  of the door base member  140 . In this state, the first end portion  142  of the door base member  140  blocks the first air inlet hole  131  of the base member  130 . In addition, since the second air inlet hole  133  of the base member  130  is blocked by an intermediate portion of the door base member  140 , the air flows along only an outer surface, not along an inner side. 
     Therefore, the inner air of the helmet does not flow to the outside through the communicating hole  103 . 
     As shown in FIGS. 9 and 10, in the above state, in the first opening step, only the door base member  140  is retracted on the base member  130  for thereby implementing an opening operation. 
     In a state that the side door member  150  is closed, when the door base member  140  is retracted, the side door member  150  is not opened, and only the first air inlet hole  131  of the base member  130  is first opened. 
     Here, the first air inlet hole  131  of the base member  130  is first opened for the reason that a retracting operation of the first elastic piece  146   a  is limited by the first protrusion  137  formed in a horizontal direction on the first lower side guide hole  136  in the base member  130 , and in this state the second stopper protrusion  146  is engaged by the second groove. The first elastic piece  146   a  may be retractable after the door base member  140  is fully opened. 
     When the first air inlet hole  131  is opened, the air flowing in through the first air inlet hole  131  flows in the rearward direction along the first air moving space  132 . At this time, since the air has a high pressure, a suction force for sucking an inner air of the communicating hole  103  formed in the helmet body  100  is generated, so that the air is discharged through the first air outlet hole  134 . 
     Therefore, in the first opening step, the inner air of the interior of the helmet is discharged to the outside. As described in the earlier description of the operation, in the first opening step, the first stopper protrusion  145  formed in the first elastic piece  145   a  may be selectively stopped by one of the multiple first grooves  135  formed in the base member  130 . 
     When a selective stop is performed, since the opening and closing degree of the first air inlet hole  131  is different, the amount of the air to be discharged from the interior of the helmet is changed. 
     In the second opening step, as shown in FIGS. 11 and 12, in a state that the first opening step is maintained, the side door member  150  of the door base member  140  is retracted for thereby opening. 
     In a state that the door base member  140  is retracted, when the door member  150  is retracted, as shown in FIG. 11, the third air inlet hole  143  of the door base member  140  is aligned with the second air inlet hole  133  of the base member, and the first air outlet hole  134  and the second air outlet hole  144  are opened. 
     Therefore, the air flowing through the first air inlet hole  131  and the aligned second air inlet hole  133  and third air inlet hole  143  flows in the rearward direction through the first air moving space portion  132 . In the rear side, the air flows through the second air outlet hole  144  and the second air moving space portion  153  of the side door member  150 . 
     Since the amounts of the inlet and outlet air are large, the force pulling the air in the surrounding portion of the communication hole  103  of the helmet body  100  is increased, so that the amount of the air in the interior of the helmet which flows through the communication hole  103  is increased. 
     In the second opening step, the second stopper protrusion  146  formed in the second elastic piece  146   a  may be selectively stopped by one of the second grooves  154  arranged in the side door member  150 . 
     In the above selective stop, since the opening and closing degree of the third air inlet hole  143  is different, it is possible to more accurately control the discharge of the air in the interior of the helmet. 
     On the contrary, when closing the air vent according to the present invention, the closing process is implemented through the second opening step in which the side door member  150  is closed, and the first opening step in which the door base member is closed. 
     The side door member  150  is first closed for the reason that the door base member is not closed while the side door member  150  is being opened. Namely, the retracting operation of the first elastic piece  145   a  of the door base member  140  is prevented by the second protrusion  156  of the side door member  150 , and the first stopper protrusion  145  is caught by the first groove  135 . Therefore, in the air vent according to the present invention, when a breath steam formation is not large, if the user wishes to gradually decrease the discharging amount of the air, it is possible to decrease the discharging amount of the air by selecting one among the first through fourth opening steps. On the contrary, when the breath steam formation of the shield is large, if the user wishes to increase the discharging amount of the air, the first and second opening steps are all performed for thereby maximizing the discharging amount of the air. 
     As described above, in the present invention, the air vent is installed at both lower sides of the shield of the helmet, so that the inner air is discharged based on the flow of the air of the air vent. In addition, it is possible to adjust the discharge of the air based on the first and second opening steps by a sliding operation of the door base member with respect to the base member and a sliding operation of the side door member with respect to the door base member. 
     Furthermore, it is possible to accurately adjust the opening degrees by dividing each of the first and second opening steps into four sub-steps, so that it is possible to accurately adjust the discharging amount of the inner air through the air vent. 
     Therefore, in the present invention, since it is possible to adjust the discharging amount of the inner air of the shield of the helmet based on a helmet user&#39;s condition and an inner and outer environment of the helmet, it is possible to implement an agreeable optimum state when using the helmet. 
     As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described examples are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.