GB1483257A - Air heating apparatus - Google Patents

Abstract

1483257 Seaming non-metallic sheet material W S FORTUNE 22 Aug 1974 [22 Aug 1973 15 July 1974] 36873/74 Heading B5K [Also Division B3] An air heating apparatus for plastics welding or plastics tube shrinking comprises an elongate heating rod including temperature sensing means for generating a control signal, a jacket body about the rod and having a nozzle outlet end and a rear portion, air inlet duct means adjacent the rear portion and means supporting the jacket body on the rod, the jacket body forming the outer wall of a chamber for heating air flowing between the inlet duct means and the nozzle outlet. In one embodiment a rod 18, Fig. 1 containing an electric resistance element carries at one end a temperature sensing element 22 for controlling the energy supplied to the element and carries at the other end a handle 14. A soldering tip 24 is located over the rod and a jacket 26 is arranged over the tip and rod, being held by a locking collar 36 on the rod, to form a chamber 28 through which air is passed from a duct 38 to a nozzle about the soldering tip. A helical spring 30 between the tip and jacket provides an elongated helical path for the air flow which may be derived from a mains supply, a hand operated bellows, bicycle pump or even the operator's mouth. In a modification the soldering tip is not employed. In another embodiment a further duct 52, Fig. 3 is suported on the jacket 46<SP>1</SP> of a tool similar to that of Fig. 1 this duct having a nozzle 60 directed towards the area to be worked on and being connected to a source of cold air to produce a thermal shock cooling or to a vacuum to draw ambient air away from the work area for cooling or to remove gaseous pollutants. In a modification the further duct surrounds the jacket to form an annular space between duct and jacket, hot air being supplied from the inner nozzle to shrink insulation tubing to a terminal of a multiprong connector while cool air is drawn or blown over adjacent terminals by the outer duct. The soldering tip may be omitted from the apparatus of Fig. 3 and its modification and instead of a helix between the heating rod and jacket foramenated ceramic material or stainless metallic wool may be used. In another embodiment a metal jacket 66, Fig. 6 is supported from a plastics bush 68 slidably disposed about a heating rod 18 carrying along the rod 18 by an operator pushing a flange 80 on the bush, a spring 92 in a bore of the bush providing positional control. Air is supplied through a duct 42 to flow about the rod 18 to emerge from the nozzle 100 formed by the jacket which latter may carry protective insulating material, e.g. silicone rubber or glass fibre. The insulating material may enable the tool to be moved through a group of insulated wires by moving them aside to allow the soldering tip to solder a terminal. Cleaning agents such as alcohol-water solutions may be atomized by air and carried with air through the jacket.