Abstract: A respiratory component mounting assembly includes a first respiratory component, a second respiratory component and a mounting clip for mounting the second respiratory component to the first respiratory component. Each of the first and second respiratory components includes at least two spaced apart clip openings. The mounting clip has an intermediate portion and two spaced apart free ends connected to the intermediate portion. The intermediate portion of the mounting clip is received within both of the clip openings of the first respiratory component and the free ends of the mounting clip are received in the clip openings of the second respiratory component for releasably securing the first and second respiratory components together.

Abstract: An anatomically fitted belt is used for carrying one or more waist-mounted respiratory protection components. The belt includes a main belt portion and a belt buckle portion. The main belt portion includes a back section, a left side section, a right side section, a left connective section between the back section and the left side section, and a right connective section between the back section and the right side section. The back section is wider than the other sections of the main belt portion. The main belt portion has a generally conical shape to be secured around a user's pelvic girdle and to align the respiratory component over the lumbar region of the user's spine to distribute a weight of the respiratory component. The belt buckle portion includes a right piece connected to the right side section of the main belt portion and a left piece connected to the left side section of the main belt portion.

Abstract: A supplied air helmet 10 comprises a visor 14 and a face seal 12 that is secured to the visor. The face seal 12 includes a sealing member 18 and a frame member 16. The sealing member 18 extends radially inward from the frame member 16 and has first and second regions of permeability 20 and 22. The second region 22 has greater permeability than the first region 20. The use of a face seal 12 that has differentiated permeability allows for a controlled flow of air through the interior of the supplied air helmet 10.

Abstract: A respirator hood 1 that has an air chamber 6 arranged above the head of a user for delivery of breathable air. The air chamber 6 has an air inlet 13 connected to an air supply hose 5 and an air outlet 17 The outlet 17 is arranged to direct air away from the eyes of the user. The air chamber 6 forms an air duct 12 that substantially covers the top of the hood 1 above the user's head. The duct 12 is collapse-resistant so that the duct shape is maintained in use and air flow through the duct 12 is substantially unrestricted. As a result, a substantially uniform air flow can be achieved in use, which air flow pattern is repeatable from day to day and from hood to hood.

Abstract: A respirator hood 1 that has an air chamber 6 arranged above the head of a user for delivery of breathable air. The air chamber 6 has an air inlet 13 connected to an air supply hose 5 and an air outlet 17. The outlet 17 is arranged to direct air away from the eyes of the user. The air chamber 6 forms an air duct 12 that substantially covers the top of the hood 1 above the user's head. The duct 12 is collapse-resistant so that the duct shape is maintained in use and air flow through the duct 12 is substantially unrestricted. As a result, a substantially uniform air flow can be achieved in use, which air flow pattern is repeatable from day to day and from hood to hood.

Abstract: A sheet element, such as a banknote, has an incorporated authenticating device comprising a film having at least one edge which is provided with a non-rectilinear portion or portions shaped to provide coded information relating to the sheet element. The shape and proportions of said at least one edge of the shaped non-rectilinear portion or portions of said film are sensed to generate a signal dependant upon the shape and proportions of the edge of the film so as to derive the coded information.

Abstract: A sheet element, such as a banknote, having an authenticating device in the form of a strip extending across the sheet and having at least one edge provided with a non-rectilinear portion or portions providing difficulty in copying for the forger and preferably shaped to provide coded information relating to the sheet element. In the case of a banknote, one or both edges of the strip may have wavy-shaped portion or portions, of which characteristics such as amplitude and periodicity can be employed to encode such information as the issuing authority, currency, denomination and serial number. Other aspects of the invention concern a method of verification comprising providing a sheet element as above and sensing the non-rectilinear edge or edges to derive the coded information, and a method of slitting a sheet comprising operating a slitting assembly to slit the sheet along a number of slitting lines into a plurality of strips as aforesaid.

Abstract: A document is provided having thereon a legible code to distinguish the document from other similar documents, the code comprising an arrangement of alphanumeric characters. Where the document is a banknote, the code may be the serial number which is unique to that banknote, and which is one of a series of such serial numbers carried on individual members of a set of such documents, and having sequential numerical values. To enhance the security value of the serial number portion of the document and to inhibit successful forgery thereof, the alphanumeric characters are provided in reverse, or negative form. The security value derives from the complexity and cost of the apparatus necessary to print a series of successive serial numbers in reverse, rather than positive form. The code may correspond to a code provided elsewhere on the document in positive form. Another reverse code on a different background may be provided elsewhere on the document.

Abstract: A sheet element, such as a banknote or other document of intrinsic value, incorporating an optical authenticating device comprising a thin film element, preferably in the form of a strip, or thread disposed within the thickness of the sheet element and having known characteristics of spectral reflectance and transmittance, and wherein in the region of a least part of the thin film element the sheet element is formed with a pair of superposed windows between which the thin film element extends so as to be visible through each window.