Helmet

Abstract: A jet type helmet comprising a shield plate (19) supported to opposite sidewalls of a cap body (1) for opening or closing a window (18), and an air intake hole (8) provided at a front wall of the cap body (1) above the window (18) for introducing the air from forward into the cap body (1) when the shield plate (19) is disposed at its closed position, wherein said helmet further comprises a diffuser (37) disposed at the edge portion of said window (18) and opened toward an inner surface of said shield plate (19) in its closed position to be communicated with the air intake hole (8). When when a wearer of the helmet is slouched at the time of travelling, a fog on the inner surface of the shield plate (19) can be eliminated by introducing an air flow.

Description: This invention relates to open-face (or jet type) helmets. JP-U-63-94924 discloses an open face helmet comprising a shield plate supported on opposite sidewalls of a cap body for opening or closing a window, and an air intake hole provided at a front wall of the cap body above the window for introducing air into the cap body when the shield plate is disposed at its closed position. When a wearer of such a helmet leans forward whilst riding a motorcycle with a shield plate of the helmet at its closed position at which the shield plate covers the window, it is difficult to introduce air into the shield plate, and the wearer's breath flows over an inner surface of the shield plate, causing it to cloud up. US 4514864 discloses a full-face type motorcycle helmet having an air inlet in its chin cover portion. The air passes along passageways formed in the lining of the helmet shell to a pair of nozzles located above the window opening in the front of the helmet. In use, with the helmet worn by the rider of a motorcycle, air flow incident on the helmet enters the air inlet, passes along the passageways and is directed from the nozzles onto the inside surface of the visor, thereby preventing fogging of the visor. The present invention seeks to provide a jet type helmet which avoids the clouding of a shield plate in its closed state due to condensation of the wearer's breath. According to the present invention, there is provided an open face helmet comprising a cap body with a window defined in the front thereof, a shield plate supported on opposite sidewalls of the cap body for opening or closing the window, an air intake hole provided at a front wall of the cap body above the window for introducing air from a forward direction into the cap body when the shield plate is disposed at its closed position and a ventilation groove extending along the inner surface of the cap body communicating with the air intake hole, characterised in that the helmet further comprises a diffuser which communicates with the air intake hole through the ventilation groove, said diffuser being disposed at the edge portion of the window and being open towards an inner surface of the shield plate when the shield plate is closed, the diffuser being formed on a mounting plate engaged with an inner pad which is disposed on the inner surface of the cap body, said mounting plate being disposed at the edge portion of the window. With such a construction, the air introduced from the air intake hole into the cap body is discharged forwardly out from the diffuser. Thus, when a wearer of the helmet leans forward with the shield plate closed, the discharged air is directed downwardly along the inner surface of the shield plate, and the downward air flow is promoted by a negative pressure generated in the lower portion of the shield plate, thereby avoiding the condensation of the wearer's breath on the shield plate. For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Fig. 1 is a side view of a helmet according to the present invention; Fig. 2 is a front view of the helmet; Fig. 3 is an enlarged bottom view as seen from an arrow III in Fig. 1; Fig. 4 is a sectional view taken along the line IV-IV in Fig. 3; Fig. 5 is a sectional view taken along the line V - V in Fig. 3; Fig. 6 is a sectional view taken along the line VI - VI in Figure 4; Fig. 7 is an exploded perspective view of a cap body and an inner fitted pad; Fig. 8 is a front bottom view of the helmet in a set that the inner fitted pad is removed; and Fig. 9 is a sectional view taken along the line IX - IX in Fig. 4. Figs. 1 to 6, show a jet type helmet. A cap body 1 of the helmet comprises a shell 2 made of hard high strength resin as an outer shell and a buffer liner 3 made of foamed styrol which is fitted into the shell 2. A pair of left and right ear cover portions 4 are integrally formed with the shell 2 and extend downwardly for covering the peripheries of the ears of a wearer of the helmet. An edge member 5 made of rubber is adhesively fitted to a lower edge of the shell 2. The buffer liner 3 is adhesively fitted in the shell 2 excluding both the ear cover portions 4. A window 18 is defined in a front wall of the cap body 1. A shield plate 19 made of transparent synthetic resin for opening or closing the window 18 is supported at its opposite ends on the cap body 1 at opposite sides of the window 18 through pivot sections 20. The shield plate 19 is turnable between a closed position indicated by a solid line in Fig. 1 and an opened position indicated by a dotted broken line in Fig. 1. Two front ventilation grooves 6a extending longitudinally of the cap body 1 are formed in a front inner surface of the buffer liner 3 near a lateral centre line thereof. And two rear ventilation grooves 6b corresponding to the front ventilation grooves 6a and extending longitudinally are formed in the rear inner surface of the buffer liner 3. The ventilation grooves 6a and 6b become shallower as they approach the top or roof of the inner surface of the buffer liner and become flush with the inner surface of the buffer liner 3 at the top of the inner surface of the buffer liner 3. The front ends of the front ventilation grooves 6a communicate with a pair of vent holes formed in the buffer liner 3, respectively, and the vent holes 7 communicate with a pair of air intake holes 8 formed in the front portion of the shell 2, respectively. A slide type opening/closing cover 9 is attached to the outer surface of the front portion of the shell 2 to open or close the air intake holes 8. A louver-like cover portion 10 having a plurality of spaced apart horizontally extending projections is integrally formed on the edge member 5 fitted to the lower edge of the shell 2 at a position corresponding to the lower end of the rear portion of the cap body 1 so as to cover the outer surface of the lower end of the rear portion of the shell 2. Two air discharge holes 11 communicating with the rear ventilation grooves 6b of the buffer liner 3 are formed in the cover portion 10. Accordingly, when a wearer of the helmet is travelling on a motorcycle, air streams are generated in the rear ventilation grooves 6b towards air discharge holes 11 by a negative pressure generated in the air discharge holes 11. Referring also to Figs. 7 to 9, a supporting sheet 12 made of flexible synthetic resin is adhered to the inner surface of the lower end of the buffer liner 3 excluding its rear portion. A cover plate 23 made of synthetic resin having a suitable rigidity is adhered to the supporting sheet 12 at portions corresponding to the front ends of both the front ventilation grooves 6a, thereby preventing the supporting sheet 12 together with an inner pad 24 from protruding into both the front ventilation grooves 6a as described later. A supporting cloth 13, knitted to have relatively big stitches in order to have air permeability, is sewn to the supporting sheet 12, and a first supporting plate 14 covering the lower end face of the front portion of the buffer liner 3 is sewn to the supporting cloth 13. The first supporting plate 14 is formed of synthetic resin having relatively high rigidity, and formed in a circular arc shape corresponding to the lower end face of the front portion of the buffer liner 3, having a substantially L-shaped cross section so as to form an insertion portion 15 to be inserted between the buffer liner 3 and the shell 2. The peripheral edge of the supporting cloth 13 excluding the first supporting plate 14 is adhered to the outer surface of the buffer liner 3 to be held between the shell 2 and the liner 3 and hence, the supporting cloth 13 covers the end faces corresponding to the front and both side portions of the buffer liner 3. A pair of communication holes 16 are formed in the first supporting plate 14 to communicate with the front ends of the front ventilation grooves 6a via a communication groove 17 formed on the lower end face of the front portion of the buffer liner 3. An end of a supporting cloth 21 for covering a lower end face of a rear portion of the buffer liner 3 is stuck to an outer surface of the buffer liner 3 at a lower end of the rear portion of the cap body 1 to be held between the shell 2 and the liner 3, and a second supporting plate 22 for covering an inner surface of the lower end of the rear portion of the buffer liner 3 is sewn to the supporting cloth 21. The supporting cloth 21 is knitted with relatively big stitches, and the second supporting plate 22 is formed of synthetic resin having relatively high rigidity. An inner pad 24 is detachably disposed inside the buffer liner 3 in the cap body 1. The inner pad 24 comprises a side pad 25 fundamentally formed in a loop shape to be brought into contact with a side portion of the wearer's head, and a ceiling pad 26 formed integrally with the side pad 25 and brought into contact with a top portion of the wearer's head. The entire surface of the side pad 25 is covered with a cloth cover 27 having air permeability. A cover extension portion 28 extend from the cover 27 for covering the lower end face of the buffer liner 3 at the front portion and opposite sides of the cap body 1. A first mounting plate 29, to be detachably engaged with the first supporting plate 14, is sewn to the cover extension portion 28. This first mounting plate 29 is formed in a circular arc shape corresponding to the lower end face of the front portion of the buffer liner 3 and is made of synthetic resin having relatively high rigidity, and is opposed to the first supporting plate 14. A pair of insertion portions 30 to be inserted between the buffer liner 3 and the shell 2 are formed at the front ends of the first mounting plate 29 closer to both peripheral ends thereof, and holding portions 31 to be held between ear pads 46 to be described later and the buffer liner 3 are provided at opposite peripheral ends of the first mounting plate 29. Guide means G for guiding a longitudinal sliding movement of the first mounting plate 29 between an engaging position and a separating position for defining a predetermined mounting position of the first mounting plate 29 with respective to the first supporting plate 14, and first locking means E₁ for detachably engaging the first mounting plate 29 with the first supporting plate 14 are provided at the first mounting plate 29 and the first supporting plate 14. The guide means G has three engaging portions 32 provided at a peripheral interval on the first supporting plate 14, and three recesses 35 provided on the first mounting plate 29 corresponding to the engaging portions 32. Each of the engaging portions 32 is elongated from the front end of the first supporting plate 14 rearwardly by cutting and bending a portion of the first supporting plate 14 downwardly from its lower surface, and each of the recesses 35 is formed by notching the front end of the first mounting plate 29 to be followed by the corresponding engaging portion 32. The first mounting plate 29 can be guided at a predetermined mounting position between the engaging position and the separating position by insertion of the engaging portions 32 into the recesses 35, respectively. The locking means E₁ has pawls 34 respectively provided on upper surfaces of rear ends of the engaging portions 32, and locking projections 33 provided on the lower surfaces of front ends of the recesses 35 to be engaged with the pawls 34. The locking projections 33 of the first locking means E₁ are urged to engaged elastically with the corresponding pawls 34 by sliding the first mounting plate 29 from the rear separating position to the front engaging position on the first supporting plate 14 while guiding the first mounting plate 29 to a predetermined mounting position by means of the guide means G. When the first mounting plate 29 is slid rearwardly from its locked state, the elastic engagement of the locking projections 33 with the pawls 34 are released, and the first mounting plate 29 is detached from the first supporting plate 14. Box-shaped protrusions 36 are formed on the lower surface of the first mounting plate 29 between the recesses 35 and protrude forwardly and downwardly. A plurality of diffusers or openings 37 are formed on the front ends of the protrusions 36, respectively so as to open in a forward direction so that they are directed to the inner surface of the shield plate 19 at its closed position. Passages 38 communicating with the communication holes 16 provided in the first supporting plate 14 are formed between the protrusions 36 and the first supporting plate 14 in a state where the first mounting plate 29 is engaged with the first supporting plate 14, and the diffusers 37 communicate with the front ends of the front ventilation grooves 6a through the passages 38, the communication holes 16 and the communications grooves 17. The ceiling pad 26 is formed in a belt shape. The pad 26 has free ends at both left and right ends, and front and rear ends sewn to the front and rear ends of the side pad 25. An inner surface of the ceiling pad 26 is provided with a pair of ventilation grooves 40 corresponding to the pair of front ventilation grooves 6a and the pair of rear ventilation grooves 6b on the inner surface of the buffer liner 3, and is also provided with a pair of guide holes 41 for communicating both the ventilation grooves 40 with the front ventilation grooves 6a, and a pair of guide holes 42 for communicating both the ventilation grooves 40 with the rear ventilation grooves 6b when the inner pad 24 is mounted in the cap body 1. If negative pressure is generated in the air discharge holes 11 when the wearer of the helmet is travelling on a motorcycle, an air flow is generated which is directed towards the rear ventilation grooves 6b through the front ventilation grooves 6a, both the guide holes 41, both the ventilation grooves 40 and both the guide holes 42. A second mounting plate 43 opposed to the second supporting plate 22 is sewn to the rear end of the side pad 25 of the inner pad 24. The second mounting plate 43 is formed of synthetic resin having relatively high rigidity, and the second supporting plate 22 and the second mounting plate 43 are detachably engaged through second locking means E₂. The second locking means E₂ has a pair of engaging holes 44 provided at a peripheral interval in the second supporting plate 22, and a pair of engaging projections 45 projecting from the second mounting plate 43 to be elastically engaged with the respective engaging holes 44. Each of both the engaging projections 45 is comprised of a shaft 45a and an enlarged locking portion 45b which is formed at a tip end of the shaft 45a via a step and is tapered so as to have a gradually reduced diameter towards its free end. The maximum outer diameter of the enlarged locking portion 45b is larger than the inner diameter of the engaging hole 44. The engaging projections 45 are elastically engaged with the engaging holes 44 by inserting the enlarged locking portions 45b into the engaging holes 44 by force. Ear pads 46 for receiving the wearer's ears are detachably mounted on an inner surface of the ear covers 4, respectively. The ear pads 46 are C-shaped and define recesses between the lower end of the buffer liner 3 and the pads 46 for receiving the wearer's ears, and are fixed to the inner surfaces of supporting plates 47 made of synthetic resin having relatively high rigidity. The supporting plates 47 are detachably engaged with the ear covers 4, respectively. Each of a pair of chin straps 48 is fixed at one end to the ear covers 4 through rivets 49. The chin straps 48 are capable of being fastened to one another so as to secure the cap body 1 to the head of the wearer. The chin straps 48 are inwardly extended through insertion holes 50 formed in the supporting plates 47. Description will now be made of the operation of this embodiment. When mounting the inner pad 24 to the cap body 1, the first mounting plate 29 is urged forwardly in a state where the plate 29 is superposed on the first supporting plate 14 so that the recesses 35 are set at positions corresponding to the locking portions 33. Then, the first mounting plate 29 is guided from the separating position to the engaging position by means of the guide means G, the locking protrusions 33 are inserted between the engaging portions 32 and the first supporting plate 14. The locking protrusions 33 are elastically engaged with the pawls 34, as a result, the first mounting plate 29 is engaged with the first supporting plate 14 by means of the first locking means E₁. The pair of insertion portions 30 are inserted between the buffer liner 3 and the shell 2 in the engaging state of the first locking means E₁ as described above, and the pair of holding portions 31 are inserted between the ear pads 46 and the buffer liner 3, thereby fixedly securing the front portion of the inner pad 24 to a predetermined position of the cap body 1. Then, the rear end of the inner pad 24 is engaged with the rear end of the cap body 1 by the second locking means E₂ thereby to complete mounting of the inner pad 24 to the cap body 1. Thus, the mounting operation is extremely easy. In the mounting operation of the inner pad 24 to the cap body 1 as described above, the first mounting plate 29 is guided by the guide means G and is engaged with the first supporting plate 14 by means of the first locking means E₁ at the predetermined engaging position. Therefore, the mounting position of the inner pad 24 to the cap body 1 is easily determined. When a person wearing the helmet is travelling on a motorcycle, with the air intake holes 8 of the front end of the cap body 1 opened, air flow is introduced from the air intake holes 8 into the front ventilation grooves 6a. A part of the introduced air is sucked out from the air discharge holes 11 through the guide holes 41, the ventilation grooves 40, the guide holes 42 and the rear ventilation grooves 6b to efficiently ventilate the interior of the cap body 1. If the wearer of the helmet leans forward with his head down in a state where the shield plate 9 is located at its closed position indicated by a solid line in Fig. 1 while travelling on a motorcycle, air flow is scarcely introduced inside the shield plate 19. A part of the air introduced from the air intake holes 8 into the cap body 1 is directed towards the inner surface of the shield plate 19 from the plurality of diffusers 37 through the communication grooves 17, the communication holes 16 and the passages 38. Inside the shield plate 19, a negative air pressure is generated at the lower portion of the shield plate 19 when the wearer of the helmet is travelling on a motorcycle in a stooped attitude, and the air discharged from the diffusers 37 is sucked by the acting of the negative air pressure such that it flows downwardly along the inner surface of the shield plate 19. Therefore, clouding of the shield plate 19 caused by the breath of the wearer of the helmet can be reliably prevented.

Claims: An open face helmet comprising a cap body (1) with a window (18) defined in the front thereof, a shield plate (19) supported on opposite sidewalls of the cap body (1) for opening or closing the window (18), an air intake hole (8) provided at a front wall of the cap body (1) above the window (18) for introducing air from a forward direction into the cap body (1) when the shield plate (19) is disposed at its closed position, and a ventilation groove (6a, 40, 6b) extending along the inner surface of the cap body (1) communicating with the air intake hole (8), characterised in that the helmet further comprises a diffuser (37) which communicates with the air intake hole (8) through the ventilation groove (6a, 40, 6b), said diffuser being disposed at the edge portion of the window (18) and being open towards an inner surface of the shield plate (19) when the shield plate is closed, the diffuser (37) being formed on a mounting plate (29) engaged with an inner pad (24) which is disposed on the inner surface of the cap body (1), said mounting plate (29) being disposed at the edge portion of the window (18). An open face helmet as claimed in claim 1, characterised in that the mounting plate (29) is provided with a box-shaped protrusion (36) which projects downwardly and forwardly from the edge portion of the window (18), air from the air intake hole (8) being directed through the protrusion (36) to the inner surface of the shield plate (19). An open face helmet as claimed in claim 2, characterised in that the ventilation groove (6a,40,6b) extends along the inner surface of the cap body (1) to the edge portion of the window (18), and in that a vent hole (7) is provided in the front surface of the ventilation groove (6a,40,6b) which vent hole (7) communicates with the air intake hole (8), the ventilation groove (6a,40,6b) being closed by a cover plate (23) superposed on the inner surface of the cap body (1) along the upper edge of the window (18) to prevent the inner pad (24) from entering the ventilation groove (6a,40,6b), the front end of the ventilation groove (6a,40,6b) communicating with the interior of the protrusion (36).

Inventors: KAMATA EITARO, KAMATA, EITARO
Applicants: SHOEI KAKO KK, SHOEI KAKO KABUSHIKI KAISHA
Application year: 1990
Main classification: A42B3
IPC codes: A42B3