Abstract: A closure for the open mouth of an airtight container. The closure has a resiliently flexible diaphragm which has a peripheral edge (37) which can sealing engage against an inside wall surface of the open mouth. The diaphragm (13) is engaged with the second cover section (12) of a cover. A pair of toggles (24) are pivotally mounted on axles (22) of second cover section (12). The levers (30) of the toggles (24) extend through an opening (44) in the first or outer cover section (11) when the first and second cover sections (11,12) are snap-locked together. By moving the levers (30) toward one another the respective feet (27) of the toggle (24) engage with area (35) of the diaphragm (13) to deform the diaphragm and thereby break a sealing effect between the peripheral edge of the diaphragm and the inside wall surface of the open mouth.

Abstract: A method of manufacturing a tungsten carbide tipped circular saw blade (S) characterised by the steps: (a) supplying a stainless sheet steel strip or blank to a laser cutting machine; (b) laser Cutting an arbor (11) and the periphery profile of the blade (S) according to a predetermined computer controlled pattern; (c) brazing the tungsten carbide saw tips to their respective locations on the periphery of the blade (S); (d) electropolishing the blade (S) to remove brazing residues and heat discolouration from the surfaces; and (e) grinding the final cutting profile to each of the tungsten carbide tips.