Abstract: A combustion head for use with a hot melt glue gun includes a glue feed passageway through which hot glue is to pass to a nozzle, and a heating chamber, the glue feed passageway and the heating chamber having a wall in common through which heat is exchanged from the heating chamber to the passageway. The heating chamber includes a combustion region to which a gas/air mixture is fed and where combustion takes place, and a passage for feeding hot exhaust gases from the combustion region over the wall in common between the heating chamber and the glue feed passageway, to an exhaust gas outlet.

Abstract: A gas heated tool such as a soldering iron has a refillable gas container (1) with an inlet valve (17, 18, 19) and an outlet valve (14) biassed mutually to the closed position by a spring (21) acting between them. The outer valve is opened by an operating member (31) which is connected to a diaphragm (30) forming part of a differential valve. This is controlled by a rotatable tube (39) with pins (43) engaging a profile on an axially movable cam member (38) which acts on the operating member (31) through a spring (37). The control tube (39) has its upper end apertured (57) to control the admission of air in accordance with its angle of rotation. Thus, the rotation of tube (39) simultaneously adjusts the differential valve to control the flow of gas from container (1), and adjusts the mixture by adjusting the air admitted. Gas passing up operating member (31) mixes with the air and is consumed in combustion head (4).

Abstract: A gas heated soldering iron comprises a soldering head having a chamber into which a gas/air mixture is fed by means of a bunsen tube to burn as a small, very hot flame. The chamber is surrounded by a flame suppression gauze which protects the flame and prevents any combustible gases outside the chamber being ignited. Gas is supplied to the bunsen tube from a fine jet to which the gas is fed at low pressure. The low pressure is regulated by a valve operating mechanism which cooperates with the depressible valve of a disposable gas canister to form a differential valve. The canister serves as a handle for the soldering iron, and is insulated from the soldering head.