The present invention relates to a hinge device for a retractable face guard on a safety helmet, the device having an attachment associated with the guard, and including a substantially flat guide portion, and a holder detachably mounted on the helmet, with guide means for the guide portion, allowing the attachment to be pivotable in the holder about an axis at right angles to the guide portion, there also being a latching means for latching the attachment in different angular positions relative the holder.

For the purpose of protection it has become more and more usual to arrange face guards on safety helmets. In such cases it is desirable to enable retraction of the face guard from a downward, operative position to an upward inoperative position. The hinge means shall here ensure that it is easy to move the guard between these positions, while also ensuring that it is well fixed in both operative and inoperative positions. Furthermore, the device must be robust and capable of withstanding use in difficult conditions, as well as not being implemented such that there is a risk of its getting caught in different obstructions when in use.

Several different types of hinge device have been proposed and are on the market, although none of them offers complete solutions to the problems mentioned above. In a type of hinge device mentioned in the introduction, according to the Swedish Patent 7802554-1, the attachment on the guard is clamped between the helmet and a holder mounted thereon. The holder is formed to clamp the attachment in different angular positions, but the stresses on the hinge will be large during pivoting, resulting in considerable

wear, which in turn results in that the fixing positions are no longer distinct after some time.

In another implementation, according to the Swedish published specification 3^1 574, friction washers and a helical spring are used to fix the guard in different angular positions by friction. One of the disadvantages of this design is that the hinge device protrudes prominently from the helmet in a transverse direction, with accompanying risk of accidents. The object of the invention is to achieve a hinge device, improved in relation to known such devices.

This is achieved in accordance with the invention in that a spring biassed latch member in the holder together with edge surfaces on the guide portion form the latching means, and by the latch member being adapted to subject the guide portion to a force substantially at right angles to an edge surface thereon, and essentially upwards in the holder guide means. The hinge device may thus be made such as to require small space, while enabling distinct positions for the guard and good resistance to wear.

It is particularly advantageous here if the edge surfaces are disposed such that a larger force is necessary to turn the guard from its operative position to its inoperative position than vice versa. The risk of retracting the guard unintentionally is thus reduced, while it can readily and quickly be lowered into its operative position. The invention will now be described in detail with the aid of embodiments illustrated on the accompanying drawing, where:

Fig 1 is a perspective view of a safety helmet on which a face guard has been mounted with the aid of n inventive hinge device;

Fig 2 is a view from above of the hinge device in Fig 1;

Fig 3 is a section along the line III-III in Fig 2;

Fig 4 is a perspective view of a further embodiment of the invention; and Fig 5 is a section corresponding to the one in Fig 3 of another embodiment.

According to Fig 1 a face guard 1 is pivotably mounted on a safety helmet 3 with the aid of a hinge device 2, and can thus be retracted from the operative position illustrated to an unillustrated inoperative position. In the hinge device 2 is included an attachment 4 associated with the guard 1, as well as a holder 5 removably mounted on the helmet 3. In this case the holder is mounted on the helmet via an attachment member 6, in which it may be displaced longitudinally between different latching positions. The attachment member 6 may of course be implemented in many different ways according to the need. As will be seen from Figs 2 and 3, the attachment 4 has a substantially flat guide portion 7, accommodated in guide means 8 in the holder 5. The attachment 4 is pivotable in the holder 5 about a pin 9, which has its axis at right angles to the guide portion 7. A latching means 10 enables latching the attachment 4 in different angular positions in relation to the holder 5 (see Fig 3). Included in the latching means are edge surfaces 11,12 on the attachment 4 and a latch member 13 disposed in the holder 5 for spring biassed coaction with the edge surfaces. The latch member 13 is here a spring plate fixed at one end in the holder 5, with its free end directed forwards.

When the attachment 4 is turned from the position depicted by full lines in Fig 3, the corner 14 between edge surfaces 11,12 will be nearer the fixed end of the latch member 13 than when the

attachment 4 is turned from the inoperative position, denoted by chain dotted lines, back to the operative position. This means that a greater force will be required to pivot the guard 1 from the operative to the inoperative position than from the inoperative to the operative position.

The latch member is suitably made of metal, while the rest of the holder 5 may suitably be made from such as plastics. The attachment 4 may also be suitably made from plastics. The holder 5 itself may be made in one piece, but it is of course possible, with retained function, to part it, e.g. along the section line illustrated in Fig 2, to facilitate fitting the latch member 13. The different parts of the holder may then be joined together in a suitable way, e.g. by gluing.

In the embodiment illustrated in Fig 4, the latch member is made integral with the holder 5, and has the further task of maintaining the stud 15 (of which only one end is illustrated) in substantially semi-circular bearing surfaces 16 (of which only one is illustrated) on the holder. The bearing surfaces open towards the latch member 13, thus securely retaining the attachment 4 in the holder 5, but even so it can be readily latched when necessary. As with the previous embodiment, a greater force is required to retract the guard to its inoperative position than to lower it into the operative position. In this case the holder is advantageously made entirely from plastics.

It is of course possible to change the size of the pivoting angle between the operative and inopera¬ tive positions by selecting other configurations and placings of the edge surfaces 11,12. The corner 14 may optionally be rounded to a greater or lesser extent for lessening the turning force necessary when a

strong latch member 13 is used. The guide portion 7 on the attachment 4 may be formed very simply by having the latch member 13 coact with the underside of the attachment 4 and by having its free end facing forwards.

In the embodiment illustrated in Fig 5, the latch member 13 comprises a spring biassed metal plate which is accommodated at two of its opposing ends in the holder 5 such as to allow for its flexural movement.