GB2172791A

GB2172791A - Support for a crash helmet visor

Info

Publication number: GB2172791A
Application number: GB08607050A
Authority: GB
Inventors: Lander Nocchi
Original assignee: Nolan SpA
Current assignee: Nolan SpA
Priority date: 1985-03-25
Filing date: 1986-03-21
Publication date: 1986-10-01
Also published as: DE3609382A1; GB8607050D0; IT8521219V0; FR2579083A1

Abstract

A support for a crash helmet visor comprises an elongate element (1) of plastics material having a shape substantially corresponding to that of the upper edge of the viewing aperture in a crash helmet, the element (1) having a plurality of studs (7) projecting therefrom in the direction of the concave curvature whereby to interconnect with cooperating holes (8) in the upper edge of a transparent curved visor screen (6) to be supported by the support. The support element (1) is provided with terminal enlargements integrally connected to connector members (3) of rounded annular shape having a central circular aperture (4) with diametrically opposed recesses which, in use, cooperate with appropriate detents formed on the crash helmet (2) by means of which the visor can be attached to the crash helmet itself. <IMAGE>

Description

SPECIFICATION A support for a crash helmet visor The present invention relates to a support for a crash helmet visor and to a visor incorporating such a support. In particular, the present invention relates to a crash helmet visor support incorporating a positioning mechanism for the visor itself, allowing the visor to be moved from a closed to an open position.

Known visors for crash helmets are usually made by moulding thermoplastic materials such as polycarbonate, either by injection moulding techniques in shaped moulds, or from flat sheet stock by vacuum forming techniques. Both production methods present significant difficulties related to the lower flowability of the plastics material. This characteristic of polycarbonate in particular can cause stresses due to local overheating and/or cooling of the material being moulded.In particular, it has been found experimentally that the stress zones are identifiable in two specific locations, the first of which are the particular complex areas which are necessary for forming the housings for the mechanisms which control the position of the visor on the helmet between its open and closed positions, and the second of which are the areas close to the mould inlet where the material to be moulded is introduced into the mould.

In the case of injection moulding, both these areas are more greatly stressed when the mould inlet through which the material passes into the mould is small. The optimum would be to have a linear inlet extending over the whole of the width of the visor; this solution, however, would imply the necessity of forming the mould with an opening not in the shape of a single hole or a set of holes (the solution normally adopted), but rather in the shape of a slot, which would form a line of mould flashing on the finished product.On the other hand, in visors produced not by moulding, but by vacuum forming, which involves cutting sheet material and subsequently heat forming it (with vacuum action) the problem presents itself in a differentway because the holes (round and other shapes) necessary for receiving the visor position control mechanism must be formed at this stage. However, during the vacuum-forming phase, because the thermoplastic material is subjected to linear shrinkages which are variable, in dependence on the form of the visor and the batch of material, these holes become not only distorted in shape, but also their position can be shifted.This leads to the production of visors having dimensions which are not constant, such that the regions where the visor is to be connected to the helmet and where the visor position control mechanisms are located, do not coincide perfectly with the corresponding components on the helmet itself. Consequently, it is possible for the visor movement to be imperfect, and sometime entirely unacceptable. In particular detents are usually provided to allow the visor to be located in one or more partly open positions as well as the fully open and fully closed positions.

The present inventiqn seeks to overcome the above-mentioned disadvantages by provide a support structure for a crash helmet visor, which incorporates parts of the visor position control mechanism of the visor itself.

According to the present invention, there is provided a support for a crash helmet visor comprising an elongate element of plastics material having a curvature substantially corresponding to that of the visor and which is provided with means for connecting it to the upper edge of the visor screen, the element having, at or adjacent its ends, connection members for attaching the assembly comprising the visor screen and the support to the crash helmet, the connection members forming part of the visor position control mechanism.

A particularfeature of the present invention is that it provides a support structure for a crash helmet visor which will allow the visor production process to be simplified.

Another advantage of the present invention is that it provides a support structure for a crash helmet visor, which is able to ensure that correct positioning movements of the visor are obtained.

One embodiment of the invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a median transverse section through a structure formed as an embodiment of the invention; Figure 2 is an exploded perspective view of the support and an associated visor screen; Figure 3 is a perspective view of the assembled visor and support; and Figure 4 is a side view of a visor incorporating the support fitted to a crash helmet.

With particular reference now to the various Figures of the accompanying drawings, the visor support shown is constituted by an element 1 of plastics material, preferably a polycarbonate, having a shallow V-shape cross section. This element is dimensioned and curved in such a way as to shape it to fit the frontal portion of a crash helmet 2 over the top of its front aperture; further, the element 1 is provided at its ends with two terminal enlargements 1' developing into respective flattened circular connectors 3 each having a substantially rounded shape with a downwardly projecting lower section 3' having a right angled corner.

At the centre of each of the connectors 3 there is formed a round hole 4 with two diametrically opposite recesses 5 able to cooperate with detents (not illustrated) housed in corresponding positions on mounts on the helmet 2 onto which the enlargements are fitted in use.

The upper edge of a visor 6 comprising a sheet of transparent synthetic material such as, for example, polycarbonate, is connected to the said element 1 and to the terminal enlargements 1' thereof, which join to the said connectors 3. This interconnection is formed preferably, by means of a coupling using studs 7 formed in the lower part of the shallow Vsection element 1, which fit into corresponding holes 8 formed in the upper edge of the visor 6. This connection can be reinforced by upsetting the studs 7 in the form of rivets, by adhesive, or the studs may simply be a snap fit in the holes.

The majority of the practical problems previously encountered in the production of crash helmet visors of the type described are thus eliminated since this does not have to have parts subjected to the particular stresses described above.

In particular, the connectors 3 do not require to have very complex shape and so upon moulding are only lightly stressed. As far as the transparent screen 6 of the visor is concerned, it is possible to form this in a mould having a linear mould inlet running along the whole of the top edge of the visor since any possible mould flashing is covered by the support structure; on the other hand, if the visor screen 6 is one which is cut out of sheet and vacuum formed to shape, the problems of dimensional constancy are avoided in that the connector assembly is now housed on the support 1 and, therefore, any possible dimensional variations in the visor screen are covered by the support when it is connected thereto. Moreover, it is possible to vary the thickness of the visor screen without having completely to re-design the vacuum forming moulds in dependence on such thickness variation.

Claims

1. A support for a crash helmet visor, comprising an elongate element of plastics material having a curvature substantially corresponding to that of the visor, and which is provided with means for connecting it to the upper edge of a visor screen, the element having, at or adjacent its ends, connection members for attaching the assembly comprising the visor screen and the support to the crash helmet, the connection members forming part of the visor position control mechanism.

2. A supportfor a crash helmet visor as claimed in Claim 1, in which the said elongate element is made from a polycarbonate and has, in transverse section, a shallow V-shape, the element being dimensioned and curved in such a way as to conform its shape to that of the frontal portion of a crash helmet in the region oftheviewing aperture thereof, and being provided, at or adjacent its ends, with two flat enlargements forming the said connection members.

3. A support for a crash helmet visor as claimed in Claim 2, in which the said flat enlargements forming the connection members have a substantially rounded conformation with a lower portion having a right angle at the centre of these enlargements there being formed a round hole in which there are formed, at diametrically opposite locations, recesses for cooperation with detents located in corresponding positions on the crash helmet.

4. A supportfor a crash helmet visor as claimed in any preceding Claim, in which the said means for connecting it to the upper edge of the visor screen comprises a plurality of projecting pins or studs extending from one face of the element.

5. A support for a crash helmet visor substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.

6. An assembly comprising a crash helmet visor support as claimed in any of Claims 1 to 5, assembled to a visor screen by studs or pins of the element passing through holes formed in the upper edge of visor screen.

7. An assembly as claimed in Claim 6, in which the studs or pins are upset to effect a riveted connection between the support and the visor screen.

8. An assembly as claimed in Claim 6, in which the connection between the studs or pins and the upper edge of the visor screen is reinforced with adhesive.

9. An assembly as claimed in Claim 6 in which the studs on the support element and the holes in the upper edge of the visor screen are so shaped and dimensioned that the studs or pins are a snap fit into the holes in the visor screen.

10. A crash helmet visor comprising a visor screen and a visor support substantially as hereinbefore described with reference to the accompanying drawings.

11.A crash helmet having a visor substantially as hereinbefore described and as claimed in any preceding Claim.