Patent Publication Number: US-6654969-B2

Title: System for controlling shield plate for helmet

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a system for controlling a shield plate in a helmet adapted to be put mainly on a vehicle rider, which comprises a click stop mechanism mounted between a cap body and a shield plate pivotally supported on the cap body, the mechanism being capable of retaining the shield plate in any of a fully closed position, a fully opened position and a plurality of intermediate opened positions, and a control lever pivotally supported on the cap body and capable of being turned between a neutral position in which the fully closing of the cap body is permitted, and a slightly opening position in which the shield plate in the fully closed position is pushed up and opened at a very small opening degree. More particularly, the present invention relates to an improvement in such a system controlling a shield plate in a helmet, including a locking means capable of restraining the shield plate in the fully closed position. 
     2. Description of the Related Art 
     A conventional shield plate controlling system in a helmet includes a locking means capable of restraining the shield plate in the fully closed position is already known as disclosed, for example, in Japanese Patent Application Laid-open No. 5-214604. 
     In the above conventional system, a locking bore is defined in an inner surface of the shield plate, and a locking pin is fixedly provided on the cap body adapted to be brought into engagement in the locking bore to lock the shield plate in the fully closed position. When the control lever is turned from the neutral position to the slightly opening position, the shield plate is pushed up from the inside by a cam formed on the control lever, whereby the locking bore in the locked shield plate is disengaged from the locking pin on the cap body. In such system, whenever the control lever is turned from the neutral position to the slightly opening position to disengage the locking bore in the locked shield plate from the locking pin of the cap body, the cam rubs the inner surface of the shield plate strongly. For this reason, when rubbing portions of the cam and the shield plate are worn during long term use of the control lever, there is a possibility that it is difficult to disengage the locking bore from the locking pin. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a system for controlling a shield plate in a helmet, wherein the restraint of the shield plate in the fully closed position and the release of the restraint can be carried out properly over a long term, utilizing the control lever, without provision of portions rubbing each other strongly. 
     To achieve the above object, according to a first aspect and feature of the present invention, there is provided a system for controlling a shield plate in a helmet, comprising a click stop mechanism mounted between a cap body and a shield plate pivotally supported on the cap body, the mechanism being capable of retaining the shield plate in a fully closed position, a fully opened position and a plurality of intermediate opened positions; and a control lever pivotally supported on the cap body and capable of being turned between a neutral position in which the full closing of the cap body is permitted, and a slightly opening position in which the shield plate in the fully closed position is pushed up and opened at a very small opening degree; wherein the control lever has a locking position permitting the control lever to turn from the neutral position in a direction opposite from the slightly opening position; wherein shield plate has an abutment projection formed on its inner surface; and wherein the control lever has a locking claw adapted to be put into abutment against a front surface of the abutment projection to inhibit the opening of the shield plate upon turning the control lever to the locking position when the shield plate is in the fully closed position. 
     With the arrangement of the first feature, when the control lever is set in the locking position after bringing the shield plate into the fully closed state, the locking claw of the control lever can be put into abutment against the front projection on the inner surface of the shield plate, to restrain the shield plate in the fully closed state. Moreover, when the shield plate is restrained or released from the restraint by the operation of the control lever, the abutment projection and the locking claw are merely put into abutment against each other and never rub each other. Therefore, the abutment projection and the locking claw are not worn due to the use of the control lever for a long term and hence, the restraint of the shield plate and the release thereof can be always carried out properly. 
     According to a second aspect and feature of the present invention, in addition to the first feature, the locking claw has a slant formed thereon so that when the control lever is in the locking position, if the shield plate is turned from an opened position to the fully closed position, the slant is pushed by the abutment projection to turn the control lever to the neutral position. 
     With the arrangement of the second feature, even when the control lever is first set in the locking position and the shield plate is then turned to the fully closed position, the abutment projection can push the slant at the upper portion of the locking claw to return the control lever to the neutral position. Therefore, the shield plate can be brought reliably into the fully closed state without being obstructed by the locking claw. 
     According to a third aspect and feature of the present invention, in addition to the first or second feature, the abutment projection is integrally connected to a toothed wall of the click stop mechanism, the toothed wall having click teeth formed on the inner surface of the shield plate. 
     With the arrangement of the third feature, the abutment projection is reinforced effectively by the relatively large toothed wall, whereby the restraint strength of the shield plate restrained in the fully closed state can be enhanced. 
     The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a helmet including a shield plate controlling system according to the present invention; 
     FIG. 2 is a partially cutaway enlarged sectional view taken from FIG. 1; 
     FIG. 3 is an exploded perspective view of essential portions of the helmet; 
     FIG. 4 is a sectional view taken along a line  4 — 4  in FIG. 2; 
     FIG. 5 is a sectional view taken along a line  5 — 5  in FIG. 2; 
     FIG. 6 is an enlarged side view of essential portions of the helmet in a fully closed state of the shield plate; 
     FIG. 7 is a sectional view taken along a line  7 — 7  in FIG. 6; 
     FIG. 8 is a sectional view taken along a line  8 — 8  in FIG. 6; 
     FIG. 9 is an enlarged side view of essential portions of the helmet for explaining how to remove the shield plate; 
     FIG. 10 is a sectional view taken along a line  10 — 10  in FIG. 9; 
     FIG. 11 is a sectional view taken along a line  11 — 11  in FIG. 2; 
     FIG. 12 is a sectional view taken along a line  12 — 12  in FIG. 2; 
     FIG. 13 is a sectional view taken along a line  13 — 13  in FIG.  12  and showing a control lever in an inoperated state; 
     FIG. 14 is a view similar to FIG. 13, but showing the shield plate brought into a slightly opened state by the control lever; and 
     FIG. 15 is a view similar to FIG. 13, but showing the shield plate brought into a fully closed state by the control lever. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will now be described by way of an embodiment with reference to the accompanying drawings. 
     Referring first to FIG. 1, reference numeral  1  denotes a full-face-type helmet for a motorcycle rider. A shield plate  4  is vertically turnably mounted at its left and right ends on left and right sidewalls of a cap body  2 , and adapted open and close a window  3  which opens in a front wall of the cap body  2 . The shield plate  4  is formed, over its entire region including its opposite ends, by a translucent or semi-translucent synthetic resin as a starting material. 
     As shown in FIGS. 2 and 3, a shallow recess  6  is defined in each of left and right outer surfaces of the cap body  2 , and a bracket plate  7  made of a synthetic resin is secured to a bottom surface of the recess  6  at two upper and lower points by screws  8  and  9 . 
     As shown in FIGS. 2 to  5 , a support tube  10  is integrally formed on a surface of the bracket plate  7  to surround the upper screw  8 . A wide fan-shaped recess  11  is provided in an upper portion of an inner wall of the support tube  10 , and a narrower notch  12  is provided in a lower portion of the support tube  10 . A visor-shaped temporarily fixing projection  13  (see FIGS. 3 and 7) is formed at an upper edge of a central portion of the fan-shaped recess  11 . Further, provided in the inner wall of the support tube  10  are a guide groove  14  extending downwards from a front end of the fan-shaped recess  11 , and a guide groove  15  extending upwards from a rear end of the notch  12 . 
     The bracket plate  7  has a protruding guide wall  16  formed therein and having an arcuate shape concentric with the support tube  10  so that the guide wall  16  is forwardly spaced away from the support tube  10  and downwards, and a notch  17  is provided at an upper portion of the protruding guide wall  16 . The protruding guide wall  16  also has a locking groove  18  provided in its outer peripheral surface. 
     A locking lever  19  is disposed between the support tube  10  and the protruding guide wall  16 , and a support shaft  20  integral with the lever  19  is rotatably fitted into a shaft bore  21  provided in the bracket plate  7  between both of the notches  12  and  17 . 
     The locking lever  19  is of a bow-shape including an upper arm  19   a  extending upwards from the support shaft  20 , and a lower arm  19   b  extending downwards and rearwards from the same. A first locking claw  23  is provided on the lower arm  19   b  for movement into and out of the notch  12  in the support tube  10 , and a second locking claw  24  is provided on the upper arm  19   a  for movement into and out of the notch  17  in the protruding guide wall  16 . The first and second locking claws  23  and  24  are provided at their tip ends with outer edges formed as slants  23   a  and  24   a  (FIG.  3 ), respectively. 
     A ring-shaped knob  25  is formed at a tip end of the lower arm  19   b , and a guide claw  26  is formed at a tip end of the upper arm  19   a.    
     The guide claw  26  is arcuate about the support shaft  20  and adapted to be brought into engagement (see FIG. 5) in the guide bore  27  provided in the bracket plate  7  and having an arcuate shape about the shaft bore  21 , thereby preventing the disengagement of the locking lever  19  from the bracket plate  7 . The guide claw  26  is also adapted to be put into abutment against one end wall and the other end wall of the guide bore  27  to define a locking position L and an unlocking position U L  of the locking lever  19 . Thus, in the locking position L (see FIG. 6) of the locking lever  19 , the first and second locking claws  23  and  24  enter the notches  12  and  17 , respectively, and in the unlocking position U L  (see FIG.  9 ), the first and second locking claws  23  and  24  retreat from the notches  12  and  17 , respectively. 
     A locking spring  28  (see FIG. 7) is mounted under compression between the bracket plate  7  and the locking lever  19  for biasing the lever  19  toward the locking position L. 
     Further, to prevent the disengagement of the locking lever  19 , the lever  19  and the support tube  10  are provided with a projection  29  and a recess  30  (see FIG. 3) which are in engagement with each other when the lever  19  is in the locking position L. 
     Further, a resilient arm  31  is integrally coupled at its opposite ends to the bracket plate  7  in front of the protruding guide wall  16 . The resilient arm  31  has a single or a plurality of stationary click teeth  32  on a front surface of a central portion thereof. 
     On the other hand, a pivot  33  is integrally provided in a projecting manner on an inner face of each of left and right ends of the shield plate  4 , so that it is loosely fitted into the support tube  10 . Locking claws  34  and  35  are formed on an outer periphery of the pivot  33  and capable of being brought into engagement in the guide grooves  14  and  15  through the fan-shaped recess  11  and the notch  12 , respectively. Outer peripheral edges of the locking claws  34  and  35  are slants  34   a  and  35   a  (see FIG. 3) capable of being brought into sliding contact with the temporarily locking projection  13  and the slant  23   a  of the first locking claw  23 , respectively. 
     A locking claw  36  is formed on the inner surface of each of the left and right ends of the shield plate  4  and capable of being brought into engagement in the guide groove  18  through the notch  17  in the protruding guide wall  16 , and a slant  36   a  (see FIG. 3) is also formed on one side of a tip end of the locking claw  36  and capable of being brought into sliding contact with the slant  24   a  of the second locking claw  24 . 
     Further, a toothed wall  38  is integrally formed on the shield plate  4  and has a large number of click teeth  37  projectingly provided on its inner peripheral surface so that they are brought into engagement with the stationary click teeth  32  with a resilient force of the resilient arm  31 . The toothed wall  38  is arcuate about the pivot  33 . Thus, the resilient arm  31  and the toothed wall  38  constitute a click stop mechanism  39  for stopping the shield plate  4  at any of a plurality of turned positions. 
     The shield plate  4  has a fully opened position, which is defined by abutment of the locking claw  36  against an upper end wall, i.e., a stopper wall  40  of the notch  17 . This fully opened position is an attaching/detaching position of the shield plate  4 , in which the locking claw  34  is matched with the fan-shaped recess  11 ; the locking claw  35  is matched with the notch  12 , and the locking claw  36  is matched with the notch  17 . 
     To attach the shield plate  4  to the cap body  2 , the pivot  33  of the shield plate  4  is aligned with the support tube  10  of the bracket plate  7  in the fully opened position of the shield plate  4 , as shown in FIG. 6, so that the locking claws  34  and  35  of the pivot  33  are brought into positions in which they can enter the fan-shaped recess  11  and the notch  12  in the support tube  10 , respectively, and the other locking claw  36  is brought into a position in which it can enter the notch  17  in the protruding guide wall  16 . 
     Thereupon, the locking claw  34  is first put into the fan-shaped recess  11  of the support tube  10 , while being sunk below the temporarily locking projection  13  by grasping the end of the shield plate  4  lightly (see a state shown in FIG.  10 ). Then, when the end of the shield plate  4  is pushed strongly toward the bracket plate  7 , the locking claw  35  enter the notch in the support tube  10 , while temporally pushing away the slant  23   a  of the first locking claw  23  of the locking lever  19  by the slant  35   a  of the clocking claw  35 , and the remaining locking claw  36  also enters the notch  17  in the protruding guide wall  16 , with the slant  24   a  of the second locking claw  24  being temporally pushed away by the slant  36   a  of the locking claw  36 . Therefore, the locking lever  19  is pushed toward the unlocking position U L , so that the locking claws  35  and  36  are temporally retracted from the notches  12  and  17  corresponding to the first and second locking claws  23  and  24 . However, when the locking claws  35  and  36  enter the notches  12  and  17 , respectively, the locking lever  19  is returned immediately to the original locking position L by the resilient force of the locking spring  28 , whereby the first and second locking claws  23  and  24  are brought into engagement with the locking claws  35  and  36  (see FIGS.  7  and  8 ). This engaged state cannot be released, unless the locking lever  19  is turned to the unlocking position U L . 
     When the shield plate  4  has been attached to the cap body  2  in the above manner, upper one of the stationary click teeth  32  and lowermost one of the movable click teeth  37  in the click stop mechanism  39  are brought into engagement with each other by the resilient force of the resilient arm  31  to provide an operative state. Thereupon, when the shield plate  4  is turned downwards around the pivot  33 , the engaged positions of the three locking claws  34 ,  35  and  36  of the shield plate  4  are shifted to the three guide grooves  14 ,  15  and  18  in the bracket plate  7 . Therefore, the states of the locking claws  34 ,  35  and  36  coupled to the bracket plate  7  are ensured further reliably. 
     On the other hand, in the click stop mechanism  39 , whenever the shield plate  4  is turned through a predetermined unit angle, the position of engagement of the stationary and movable click teeth  32  and  37  with each other can be changed, while flexing the resilient arm  31  to provide a moderation, and the shield plate  4  can be retained in its turned position. 
     In this case, particularly, the resilient arm  31  having the stationary teeth  32  at its central portion is connected at its opposite ends to the bracket plate  7 , namely, is supported in a straddling manner. Therefore, when the direction of turning movement of the shield plate  4  is changed to an upward direction or a downward direction, even if a point of pushing of the movable clock tooth  37  to the stationary click tooth  32  is shifted from one side of the tooth to the other side, a change is not caused in total length from the pushing point to the opposite ends of the resilient arm  31 . Thus, the resistance of the resilient arm  31  against flexing is also not changed and hence, constant moderation can be always provided. 
     Referring to FIGS. 2,  3  and  11  to  13 , a support tube  50  is integrally provided in a projecting manner on one side of the cap body  2 , desirably on the outer surface of the left bracket  7 , to surround the screw  9 . The support tube  50  is divided into a pair of upper and lower support tube walls  50   a  and  50   b  by notches  51 ,  51  extending along a diametrical line on the support tube  50 . An annular boss  52   a  of a control lever  52  made of a synthetic resin is rotatably fitted over an outer periphery of the support tube  50 , and a retaining plate  53  is secured to the cap body  2  along with the bracket plate  7  by the screw  9 , and has a pair of collars  53   a  and  53   b  opposed to an upper surface of the annular boss  52   a , while being in engagement in the notches  51 ,  51 . Therefore, the state of the annular boss  52   a  fitted over the support tube  50  is retained by the retaining plate  53 . The screw  9  and the annular boss  52   a  are adapted to be covered with the shield plate occupying a fully closed position. 
     The control lever  52  includes a cam  52   b  connected to a lower end of the annular boss  52   a  and opposed to the lower end edge of the shield plate  4 , and a knob  52   c  extending outwards of the shield plate  4  and rearwards of the support tube  50  from the cam  52   b , so that the control lever  52  is turned about a neutral position N (see FIG. 13) forwards to a slightly opening position A (see FIG. 14) and rearwards to a locking position B (see FIG. 15) by the knob  52   c.    
     Three click notches  54  are defined at equal distances in a circumferential direction in an outer peripheral surface of the upper support tube wall  50   a  in correspondence to the three positions N, A and B, so that the control lever  52  can be retained in any of the three positions N, A and B. On the other hand, a click projection  55  is formed on an inner peripheral surface of the annular boss  52   a , so that it can be selectively brought into engagement in any of the click notches  54 . 
     A single gap  56  is provided in the annular boss  52   a  to provide a radial resilience to the annular boss  52   a , so that the click projection  55  can be resiliently brought into engagement in any of the click notches  54 . 
     Further, an arcuate recess  57  is defined in the inner peripheral surface of the annular boss  52   a  and adapted to be brought into engagement with one of the collars  53   a  of the retaining plate  53 , so that the maximum angle of rotation from the locking position B to the slightly opening position A of the control lever  52  is defined by abutment of the collar  53   a  against circumferentially opposite end walls of the recess  57 . 
     When the control lever  52  is set in the neutral position N, it permits the full closing of the shield plate  4 . When the control lever  52  is turned from the neutral position N to the slightly opening position A, the cam  52   b  pushes the lower end edge of the shield plate  4  slightly upwards to provide a very small opening degree to the shield plate  4 . The very small opening degree of the shield plate  4  at that time is set smaller than a unit opening degree of the shield plate  4  defined by the click stop mechanism  39 . 
     A locking means  60  is mounted between the control lever  52  and the shield plate  4  and adapted to restrain the shield plate  4  in the fully closed position, when the control lever  52  is set in the locking position B. The locking means  60  is comprised of an abutment projection  61  formed on the inner surface of the shield plate  4  integrally with the toothed wall  38  of the click stop mechanism  39 , and a locking claw  52   d  projectingly provided at a rear portion of the annular boss  52   a . When the shield plate  4  is in the fully closed state, if the control lever  52  is turned to the locking position B, the locking claw  52   d  is put into abutment against a front surface of the abutment projection  61  to restrain the shield plate  4  in the fully closed position. 
     A slant  62  is formed at an upper portion of the locking claw  52   d , so that when the shield plate  4  is fully closed after the control lever  52  is first set in the locking position B, the abutment projection  61  pushes the slant  62  to return the control lever  62  to the neutral position N. 
     The operation of the present embodiment will be described below. 
     In a state in which the control lever  52  has been set in the neutral position N, the locking claw  52   d  of the control lever  52  is out of a path of turning movement of the abutment projection  61  of the shield plate  4 , a shown in FIG.  13 . Therefore, it is possible for an operator to put his finger or fingers on the lower end edge of the shield plate  4  to turn the shield plate  4  from the fully closed position to a desired opening degree without being interfered by the locking claw  52   d.    
     When the shield plate  4  is in the fully closed position, if the control lever  52  is turned from the neutral position N to the slightly opening position A, as shown in FIG. 14, the cam  52   b  can push the shield plate  4  to open it to the very small opening degree smaller than the unit opening degree of the shield plate  4  defined by the click stop mechanism  39 . Thus, travel wind can be supplied in a small amount to the window  3  from below the shield plate  4  to ventilate the cap body  2  moderately. 
     When the control lever  52  is set in the locking position B after bringing the shield plate  4  into the fully closed state, as shown in FIG. 15, the locking claw  52   d  of the control lever  52  is put into abutment against the front surface of the abutment projection  61  on the inner surface of the shield plate  4  to inhibit the opening of the shield plate  4 . Therefore, even if the helmet is subjected to a strong wind or a vibration, the voluntary movement of the shield plate  4  from the fully closed position can be prevented. 
     Moreover, when the shield plate  4  is restrained or released from the restraint by operation of the control lever  52 , the abutment projection  61  and the locking claw  52   d  are merely put into and out of abutment against each other and cannot rub each other. Therefore, even if the abutment projection  61  and the locking claw  52   d  cannot be worn due to the use of the control lever for a long term and hence, the restraint of the shield plate  4  and the release thereof can be always carried out properly. 
     Furthermore, since the abutment projection  61  is formed on the inner surface of the shield plate  4  integrally with the toothed wall  38  of the click stop mechanism  39 , the abutment projection  61  is reinforced effectively by the relatively large toothed wall  38 , whereby the restraint strength of the shield plate  4  restrained in the fully closed position can be enhanced. 
     When the shield plate  4  is in the opened state, if the control lever  52  is first set in the locking position B and the shield plate  4  is then turned to the fully closed position, the abutment projection  61  can push the slant  62  at the upper portion of the locking claw  52   d  to return the control lever  52  to the neutral position N. Therefore, the shield plate  4  can be reliably brought into the fully closed state without being obstructed by the locking claw  52   d . Thereafter, if the control lever  52  is set again in the locking position B, the shield plate  4  is restrained in the fully closed position, as described above. 
     Although the embodiment of the present invention has been described in detail, it will be understood that the present invention is not limited to the above-described embodiment, and various modifications in design may be made without departing from the spirit and scope of the invention defined in the claims.