DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0025] As a structure for embodying the aforementioned claim 1, as shown in FIGS. 1 to 5, for example, a structure can be made, which includes: a chin-ventilation shutter supporting part fixed to a shell side; a first guide shaft (S1) and a second guide shaft (S2) for guiding turning in any one side of a chin-ventilation shutter being supported in a rotatable way; an engaging part being formed by plural arc shapes in accordance with 2 guide axes on another side, in which: the aforementioned first engaging part (U1) and the aforementioned second engaging part (U2) formed continuously thereto for the aforementioned first guide shaft (S1) and a third engaging part (U3) for the aforementioned second guide shaft (S2) are engaged and included respectively in a movable way,

[0026] the aforementioned first guide shaft (S1) and the aforementioned second guide shaft (S2) are guided by the aforementioned first engaging part (U1) and the aforementioned third engaging part (U3) respectively at a first stage of opening the aforementioned chin-ventilation shutter and a turning operation is performed about a first central point (P1) being a common center of an arc which both engaging parts have, and a turning center is switched to a second central point (P2) which the aforementioned second engaging part (U2) has from the aforementioned first central point (P1) at a time that the aforementioned first guide shaft (S1) reaches at a connecting point of the aforementioned first engaging part (U1) and the aforementioned second engaging part (U2) and rotates about the aforementioned second guide shaft (S2) on a way to an opening operation. (claim 2)

[0027] According to the supporting structure of the present invention, the first central point P1 is a central point for turning a chin-ventilation shutter 1 for the operation for opening in FIGS. 5A to 5C. While the first engaging part U1 and the third engaging part U3 become the condition of FIG. 5C, the turning center point of chin-ventilation shutter 1 is switched to the second central point P2, and then the opening operation of FIGS. 5D to 5E is performed. Then, the volume of protruding the chin-ventilation shutter 1 outward from the surface of the chin guard part A1 can be suppressed to the extent of a minimum level in a full open condition as shown in FIG. 5E and FIG. 4.

[0028] The embodiment of the above-mentioned example is the embodiment having two turning center points of the chin-ventilation shutter 1. The present invention is not limited thereto, but the embodiment, which has more than two turning center points using a turning center point moving on the way to which the engaging part turns in the same way as an engaging part (FIG. 7) structured by connecting, by way of a curved portion having some degrees, a straight line and an engaging part (FIG. 6) including an arc having different curvatures, is included therein.

[0029] In the drawings, each engaging part is provided in the chin-ventilation shutter 1, and each guide shaft is provided in a shutter supporter 2, the present invention includes a reverse supporting structure of the embodiment thereof.

[0030] In claim 2, each engaging part can be any form of a hole structure and a channel structure if each engaging part has a form of engaging each guide axis.

[0031] Further, in the case of claim 2, as shown in FIG. 8, it is made possible that the first engaging part (U1) and the second engaging part (U2) to which said first guide shaft (S1) engages in a movable way and the third engaging part (U3) to which the second guide shaft (S2) engages in a movable way are formed in a grooved shape, and

[0032] a step is provided in the second engaging part (U2) and the third engaging part (U3) and a crossing portion of both engaging portions is also formed in order for each axis not to escape to another engaging part. (claim 3)

[0033] [Preferred Embodiment]

[0034] The embodiment of the present invention is explained hereinafter with reference to drawings.

[0035] FIG. 1 shows a full-face type helmet A and includes a ventilating hole A2 that is opened or closed by a chin-ventilation shutter 1 in a chin guard A1 as shown in FIGS. 3 and 4.

[0036] The full-face type helmet A of the present embodiment is a publicly known embodiment which includes a shock absorbing liner C structured of expanded polystine stylofoam or material having the same kind of absorbing efficiency inside a shell B formed in the predetermined shape by fiber-strengthen resin, an inner pad D of a head portion, which is made of carbamic acid ester provided inside the shock absorbing liner C thereof in an attachable and detachable way, cheek pads DL and DR provided in both sides corresponding to the cheek and chin portions, and a shield E formed in the predetermined form using a resin plate having a transparent or colored transparent property and an elastic property.

[0037] The chin-ventilation shutter 1 is supported by a shutter supporter 2 attached to a chin guard part A1 in a rotatable way, and its surface is formed as a single face to a surface of the shutter supporter 2 in a full open condition.

[0038] The chin-ventilation shutter supporter 2 includes a ventilating hole 3 that is opened and closed by the chin-ventilation shutter 1 and attached to a through hole A3 that is opened by the chin guard part A1, and the surface thereof is formed as a single face to the chin guard part A1.

[0039] The chin-ventilation shutter 1 is supported by the shutter supporter 2 in a rotatable way by engaging the first guide shaft S1 and the second guide shaft S2 provided in the right and left hand sides of the chin-ventilation shutter supporter 2 with the first engaging part U1 and the second engaging part U2 provided in the right and left hand sides of a shutter 11.

[0040] To give an actual example, as shown in FIGS. 2 to 5, the first engaging part U1 and the second engaging part U2 are opened by supporters 1L and 1R integrally formed in the right and left hand sides of the shutter 11, and the first guide shaft S1 and the second guide shaft S2 are formed protrusively in supporters 3L and 3R integrally formed so as to face with the aforementioned supporters 1L and 1R in the right and left hand directions of the ventilating hole 3. The chin-ventilation shutter 1 is supported by the shutter supporter 2 in a turning way by engaging the first guide shaft S1 with the first engaging part U1 and the second guide shaft S2 with the third engaging part U3 respectively.

[0041] The chin-ventilation shutter 1 is set so as to open and close by turning at two turning central points of the first central point P1 and the second central point P2, and it is designed such that the turning central point is switched to the second central point P2 from the first central point P1 on the way to which the opening condition is changed to the closing condition as shown in FIGS. 5A to 5E.

[0042] In the following, the structure for switching the turning central point is explained in detail. As shown in FIGS. 5A to 5E, the first engaging part U1 and the third engaging part U3, in an opening condition after the closing condition of the chin-ventilation shutter 1, draw different arcs C1 and C2 having respective different radii about the turning central point of the first central point P1 at first. Then, the turning central point is switched to the second central point P2 having the same axis as the second guide shaft S2 from the first central point P1 on the way to which the chin-ventilation shutter 1 is turned to be open. Further, a shape is formed such that the second engaging part U2 draws an arc C3 about the turning central point of the second central point P2 in the turning operation after the second engaging part U2 is switched.

[0043] The first engaging part U1 and the second engaging part U2 are linked in a point in which the first central point P1 is switched to the second central point P2.

[0044] A position in which the central point is switched is a position in which a curved portion U11 of the first engaging part U1 touches the first guide shaft S1 on the way to which the chin-ventilation shutter 1 is turned, it is ended to turn about the turning central portion of the first central point P1, and also an end portion U31 of the third engaging part U3 touches the second guide shaft S2. (refer to FIG. 5C)

[0045] The opening and closing operation of the chin-ventilation shutter 1 based on thus structured supporting structure is explained with reference to FIGS. 5A to 5E.

[0046] First of all, as shown in FIG. 5A, in the condition in which the chin-ventilation shutter 1 is closed, the starting portion U12 of the first engaging part U1 touches the first guide shaft S1 and the second guide shaft S2 is positioned in a position (a starting portion U32 of the third engaging part U3) where the second engaging part U2 and the third engaging part U3 cross with each other.

[0047] Next, the chin-ventilation shutter 1 is turned to be open after the full closed condition, as shown in FIG. 5B, the first engaging part U1 and the third engaging part U3 are guided by the first guide shaft S1 and the second guide shaft S2 and then the chin-ventilation shutter 1 turns about the turning center point of the first central point P1.

[0048] Then, when the chin-ventilation shutter 1 turns further, at the point indicated in FIG. 5C, the curved portion U11 of the first engaging part U1 touches the first guide shaft S1, the end portion U31 of the third engaging part U3 touches the second guide shaft S2, and then the turning center point is switched to the second central point P2 from the first central point P1.

[0049] If the chin-ventilation shutter 1 is turned to be open from this point, as indicated in FIG. 5D, the second engaging part U2 is guided by the first guide shaft S1 and the chin-ventilation shutter 1 turns about the turning center point of the second central point P2.

[0050] Further, for the full open condition, as shown in FIG. 5E, the end portion U21 of the second engaging part U2 touches the first guide shaft S1 and then the chin-ventilation shutter 1 stops turning.

[0051] According to the supporting structure of the present embodiment, for the full open condition, it is possible to open the whole region of the ventilating hole 3 without protruding the top end portion of the chin-ventilation shutter 1 from the surface of the shutter supporter 2 in the outer direction.

[0052] FIGS. 6 and 7 explain each case that two or more turning center points are provided in the chin-ventilation shutter 1.

[0053] At this stage, engaging parts of FIG. 6 are defined as the first engaging part U10, the second engaging part U20, and the third engaging part U30 respectively. Engaging parts of FIG. 7 are defined as the first engaging part U10′, the second engaging part U20′, and the third engaging part U30′ respectively.

[0054] For the forms of the first engaging part U10 and the third engaging part U30 of FIG. 6, each curvature of the arc of the engaging part changes at a halfway point and each turning center point for turning along the arc having different curvature exist.

[0055] To give an actual example, the radius of an arc C5 at the aforementioned halfway turning center point to the end portion is lengthened than an arc C4 at the starting portion to the halfway turning center point. Thus, the position of the first central point P3 as the turning center point of an arc C4 is different from the second central point P4 as the turning center point of an arc C5.

[0056] That is to say, the turning center point of the arc C4 is the first central point P3. When a turning operation is switched to the turning operation along the arc C5 smoothly from this halfway turning operation, the turning center point moves to the second central point P4 from the first central point P3 gradually, thus it is switched to the second central point P4.

[0057] In this case, there exist plural center points between the first central point P3 and the second central point P4 because it is performed to turn along the arc C5 when the turning center point moves to the second central point P4 from the first central point P3.

[0058] Then, while it is ended to turn along the arc C5 having the turning center point of the second central point P4, it is started to turn along an arc C6 having the turning center point of the third center point P5.

[0059] Therefore, the turning center points of the chin-ventilation shutter of the aforementioned embodiment have three points, such as the first, second, and third center point, and plural center points existing between the first central point P3 and the second central point P4. It is also possible to embody a structure in which there exist three or more turning center points.

[0060] The embodiments of the first engaging part U10′, the second engaging part U20′, and the third engaging part U30′ of FIG. 7 have a form structured by connecting plural straight lines ST1 to ST9 by way of each shape's curved portion.

[0061] This structure is made such that the turning operation is regulated at the time that each guide shaft touches the curved portion in turning operation of the chin-ventilation shutter. Using this regulation, a ratchet function comes to be effective to the operation of opening the chin-ventilation shutter.

[0062] Further, for this structure, strictly speaking the chin-ventilation shutter cannot move as a turning movement since the chin-ventilation shutter moves along each straight line, but the chin-ventilation shutter performs the movement nearly the same as the turning movement in view of the whole movement of the chin-ventilation shutter.

[0063] That is to say, since it is performed to try to turn by moving along each straight line, a gap is caused during the movement thereof. In general, it can be judged that it is performed to turn about the turning center point of a turning center point P6 and center point P7.

[0064] Therefore, the embodiment of the present invention has two or more turning center points.

[0065] Although the first engaging part U1 and the second engaging part U2 of the aforementioned embodiment are explained as through holes, it is possible for the present invention to have a channel structure arbitrarily as shown in FIG. 8.

[0066] In the following, although the embodiment of the first engaging part and the second engaging part having the channel structure of the present invention are explained hereinafter, reference characters U1′, U2′ and U3′ are used to the first engaging part, the second engaging part, and the third engaging part of the present invention respectively.

[0067] Further, the reference characters S1′ and S2′ are used to the first guide shaft and the second guide shaft respectively.

[0068] For the basic outer shape, the first engaging part U1′, the second engaging part U2′, and the third engaging part U3′ are totally the same as the first engaging part U1, the second engaging part U2, and the third engaging part U3 respectively.

[0069] The height position of the bottom face U3 of the third engaging part U3′ is positioned in one step lower position than the bottom face U4 of the first engaging part U1′ and the second engaging part U2′. Accordingly, a wall face type step difference W is formed around the third engaging part U3′.

[0070] The first guide shaft S1′ has an approaching length to a bottom portion U4 of the first engaging part U1′. The second guide shaft S2′ has an approaching length to the bottom portion U3 of the third engaging part U3′. The second guide shaft S2′ is held by the aforementioned step difference W and it is kept to be securely engaged to the inside of the third engaging part U3′.

[0071] According to the present embodiment, in the same way as the aforementioned embodiment, for the full open condition, the whole area of the ventilating hole 3 can be opened without letting the top end portion of the chin-ventilation shutter 1 protrude in the outer direction from the surface of the shutter supporter 2. Besides, the second guide shaft S2′ can be maintained in the third engaging part U3′ more securely by the step difference W.

[0072] FIG. 9 is another embodiment of the chin-ventilation shutter 1.

[0073] The chin-ventilation shutter 1 of the embodiment is provided, at the rear portion of the shutter 11, with a flow regulating plate 12 for use in regulating flow of running wind flowing into the helmet at the ventilation port.

[0074] A first engaging part U1 and a second engaging part U2 of the embodiment are constructed to have a grooved shape shown in FIG. 8.

[0075] The flow regulating plate 12 is comprised of a first flow regulating plate 12A fixed and attached over supporters 1L, 1R integrally formed at both right and left portions of the shutter 11, and a second flow regulating plate 12B vertically installed over the central part of the first flow regulating plate and the shutter.

[0076] The first flow regulating plate 12A divides the ventilation port into an upper segment and a lower segment at a substantial central location, and the second flow regulating plate 12B divides the lower portion of the ventilation port divided into two upper and lower segments into a right segment and a left segment at a substantial central location.

[0077] In accordance with the chin-ventilation shutter 1 constructed as above, the running wind flowed into the helmet through the ventilation port can be concentrically flowed into the helmet by the flow regulating plate 12 without being dispersed.

[0078] As described above, the present invention can open, for the full open condition of the chin-ventilation shutter, the whole area of a ventilating hole without letting the top end portion of the chin-ventilation shutter protrude in the outer direction from the surface of the shutter supporter.

[0079] Therefore, it is possible to increase the amount of outside air's channel, also have straightforward visual appearance.

[0080] Further, according to the invention recited in claim 2, it is possible to provide concretely a supporting structure having the aforementioned effects.

[0081] Further, according to the invention recited in claim 3, in addition to the aforementioned effect, the second guide shaft is kept securely in the third engaging part by a step difference, thus it is made real to have excellent effects when the chin-ventilation shutter is securely guided and turned without letting the second guide shaft protrude from the third engaging part at the time of opening the chin-ventilation shutter.

[0082] Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it will be appreciated that the present invention is not limited to those precise embodiments, and that various changes and modifications can be effected therein by one of ordinary skill in the art without departing from the scope of the invention as defined by the appended claims.