IMPROVEMENTS IN OR RELATING TO HELMETS

Abstract: A visor mounting for a helmet (1) comprising support means (2) for providing a visor support (25) at each side of the helmet and a four-bar linkage (25-27) at each side of the helmet for movably mounting a visor (20) to the visor supports (25) to enable the visor to be moved between lowered and raised positions. The invention also relates to a helmet provided with a visor mounting.

Description: Improvements in or Relating to Helmets This invention relates to a helmet and to a visor mounting for a helmet. Typically, but not exclusively, the helmet is intended for use by operatives in industrial environments, e.g. inv the mining or quarrying industries. Helmets provided with visors which can be pivoted upwardly and downwardly between raised and lowered positions are well known. Many different types of visor mounting are known in the art in which the visor is pivotally supported or guided at opposite sides of the helmet. For example it is known to provide separate pivots at each side of the helmet or to provide fixed pins at each side of the helmet which are received in arcuate slots in side portions of the visor to guide the visor during movement between its raised and lowered positions. The present invention seeks to provide a novel type of visor mounting for a helmet providing positive guiding of the visor during movement of the visor between raised and lowered positions. According to one aspect of the present invention a helmet having a visor and visor mounting means for movably mounting the visor to the helmet at each side of the helmet to enable movement of the visor between raised and lowered positions, is characterised in that each visor mounting means comprises a four-bar linkage. Preferably each four-bar linkage comprises a drag- link mechanism. Suitably the visor has opposite side portions each providing one of the links of the associated four-bar linkage. The helmet may include a ring-like supporting element intended, in use, to surround a user's head, one of the links of each four-bar linkage being provided by, or fixed to, opposite side portions of the supporting element. Conveniently one of the moveable links of one of the four-bar linkages actuates an electric switch on movement of the visor into or out of its lowered position. According to another aspect of the present invention a visor mounting for a helmet comprising a visor having opposite side portions, and connection means for connecting the visor side portions to visor supports at opposite sides of the helmet to enable the visor to move between raised and lowered positions, is characterised in that each connection means comprises a pair of connecting links pivotally connected between the visor side portion and the visor support at each side of the helmet and forming therewith a four-bar linkage. Conveniently each four-bar linkage comprises a drag- link mechanism having a stationary link formed by the visor support, a coupler link formed by said side portion of the visor, and crank and lever links provided by said connecting links. An embodiment of the invention will now be described, by way of example only, with particular reference to the accompanying drawing, the sole figure of which is a sectional view of a helmet according to the present invention. The drawing shows a helmet 1 having a main frame in the form of a plastics ring-like or circumferential support 2. The lower edge of a helmet shell 3 is secured, e.g. bonded, to the support 2 and the sheel and support form a rigid structure. At the rear of the support 2 there is a tubular air inlet opening 4 intended to receive a filter element (not shown) and. at the front of the support there are a number of tubular openings 5. A flexible ducting member 6 positioned close to the inside of the shell 3 connects the opening 4 . to the openings 5. The ducting member 6 has a single main inlet chamber 7 connected to the opening 4 and four outlet ducts 8 (only one of which can be seen in the drawing) connected to the openings 5. The inlet chamber 7 opens into two intermediate ducts 9 in each of which is received an electric suction fan 10. When a filter element is arranged in the opening 4, filtered air is drawn up through the opening 4 and along the ducts of the ducting member 6 before being passed out through the openings 5. The support 2 is provided with means for carrying a harness arrangement (not shown) . The harness arrangement suitably includes an adjustable headband and webbing (not shown) which sits on the crown of a wearer's head. The support 2 also has cheek protecting portions 11 extending downwardly at its opposite sides. Ear defenders (not shown) are also intended to be fitted to opposite sides of the support 2. A helmet of this general type is shown in GB-A-2298778. The helmet 1 is provided with a visor 20 movable between raised and lowered positions. The visor 20 has a bulbous transparent front viewing portion 21 and opposite side portions 22 joined to opposite sides of the support 2 by separate connecting means, generally designated 23. Each connecting means 23 comprises a stationary carrier 25 mounted on the support 2 and a pair of rigid connecting links 26 and 27 each pivotally connected at one end to carrier 25 and at its other end to its associated visor side portion 23. The connecting means defines a so-called four- bar linkage, in particular a drag-link mechanism, in which the connrcting links 26 and 27 comprise the "crank" and "lever" of the mechanism, the carrier 25 provides the shortest, stationary link of the mechanism and the visor side portion 23 provides a "coupler" of the mechanism. The connecting means enable the visor to be moved between raised and lowered positions (as shown) in a controlled and precise manner. One of the links may be designed to operate an electric switch 30, e.g. a microswitch, for activating the electric fans 10 as the visor is moved into its lowered position. As can be seen in the drawing, the link 27 is not straight but is specially shaped to enable it to operate the switch 30 before coming into contact therewith. The corresponding link on the other side of the helmet need not of course be so shaped since a switch 30 is only provided at one side of the helmet. The corresponding pivot axes for the corresponding pivots of the two connecting means at each side of the helmet will preferably be aligned with each other. The stationary links of each four-bar linkage may, instead of being provided by the carrier 25, be formed as an integral part of the circumferential support 2. Alternatively, the stationary link could even be fixed to, or form part of, the shell 3.

Claims: CLAIMS 1. A helmet (1) having a visor (20) and visor mounting means (26,27) for movably mounting the visor to the helmet at each side of the helmet to enable movement of the visor between raised and lowered positions, characterised in that each visor mounting means (26,27) comprises a four-bar linkage. 2. A helmet (1) according to claim 1, characterised in that each four-bar linkage comprises a drag-link mechanism. 3. A helmet (1) according to claim 1 or 2, characterised in that the visor (20) has opposite side portions (22) each providing one of the links of the associated four-bar linkage. 4. A helmet according to claim 1, 2 or 3, characterised in that the helmet includes a ring-like supporting element (2) intended, in use, to surround a user's head, one of the links of each four-bar linkage being provided by, or fixed to, opposite side portions of the supporting element. 5. A helmet according to claim 4, characterised in that a lower edge of a helmet shell (3) is fixed to the supporting element (2) . 6. A helmet according to any of the preceding claims, characterised in that a moveable link (27) of one of the four-bar linkages actuates an electric switch (30) on movement of the visor (20) into and/or out of its lowered position. 7. A visor mounting for a helmet comprising a visor (20) having opposite side portions (22) , and connection means (26,27) for connecting the visor side portions (22) to visor supports (25) at opposite sides of the helmet to enable the visor to move between raised and lowered positions, is characterised in that each connection means (26,27) comprises a pair of connecting links pivotally connected between the visor side portion and the visor support at each side of the helmet and forming therewith a four-bar linkage. 8. A visor mounting according to claim 7, characterised in that each four-bar linkage comprises a drag-link mechanism having a stationary link formed by the visor support (25) , a coupler link formed by said side portion (22) of the visor, and crank and lever links (26,27) provided by said connecting links. AMENDED CLAIMS [received by the International Bureau on 10 June 1997 (10.06.97); original claims 1-8 replaced by amended claims 1-5 (2 pages)] 1. A helmet (1) comprising a helmet shell (3), a visor (20) having a front viewing portion (21) and opposite side portions (22) and visor mounting means (26,27) at each side of the helmet for movably mounting the visor to the helmet to enable movement of the visor viewing portion (21) between a raised portion inside the helmet shell (3) and a lowered position at the front of the helmet, each visor mounting means comprising a stationary link (25) fixed relative to the helmet shell (3) , a coupler link formed by a respective side portion (22) of the visor and crank and lever links (26,27) connecting the stationary and coupler links, the links being constructed and arranged so that the coupler link is positioned in a forward position when the viewing portion (21) is in the lowered position and a rear position when the visor viewing portion is in the raised position, characterised in that the visor viewing portion is of bulbous shape and in that each visor mounting means (26,27) is arranged so that the coupler link is positioned in front of the stationary link when the visor viewing portion (21) is in the lowered position and is positioned behind the stationary link when the visor viewing portion (21) is in its raised position, the coupler link moving over the stationary link on movement of the visor viewing portion between its raised and lowered position. 2. A helmet according to claim 1, characterised in that the helmet includes a ring-like supporting element (2) , intended, in use, to surround a user's head, the stationary link of each four-bar linkage being provided by, or fixed to, opposite side portions of the supporting element. 3. A helmet according to claim 2, characterised in that a lower edge of the helmet shell (3) is fixed to the supporting element (2) . 4. A helmet according to any of the preceding claims, characterised in that a moveable link (27) of one of the four-bar linkages actuates an electric switch (30) on movement of the said front viewing portion (21) into and/or out of its lowered position. 5. A visor mounting for a helmet comprising a helmet shell (3) , a visor (20) having a front viewing portion (21) and opposite side portions (22) , and connection means (26,27) for connecting the visor side portions (22) to visor supports (25) at opposite sides of the helmet to enable movement of the visor viewing portion (21) between a raised position inside the helmet shell (3) and a lowered position at the front of the helmet, each connection means (26,27) comprising a drag-link mechanism having a stationary link (25) formed by the visor support (25) , a coupler link formed by said side portion (22) of the visor, and crank and lever links (26,27) connecting the stationary and coupler links, the links being constructed and arranged so that the coupler link is positioned in a forward position when the visor viewing portion (21) is in the lowered position and a rear position when the visor viewing portion (21) is in the raised position, characterised in that the visor viewing portion is of bulbous shape and in that each visor mounting means (26,27) is arranged so that the coupler link is positioned in front of the stationary link when the visor viewing portion (21) is in the lowered position and is positioned behind the stationary link when the visor viewing portion (21) is in its raised position, the coupler link moving over the stationary link on movement of the visor viewing portion between its raised and lowered position.

Inventors: BULBROOK LEE GEORGE, FORREST JACQUES WILLIAM, PATON COLIN ANDREW, BULBROOK, LEE, GEORGE, FORREST, JACQUES, WILLIAM, PATON, COLIN, ANDREW
Applicants: BULBROOK LEE GEORGE, CENTURION SAFETY PRODUCTS LTD, FORREST JACQUES WILLIAM, PATON COLIN ANDREW, BULBROOK, LEE, GEORGE, FORREST, JACQUES, WILLIAM, PATON, COLIN, ANDREW
Application year: 1997
Main classification: A42B3
IPC codes: A42B3