| 摘要 |
<p>An electrically-heated hot-melt adhesive applicator, of the kind comprising a reservoir for melting, a pump, an applicator and a connection hose, is characterised by the fact that the temperature is controlled by means of electronic proportional controllers, such control optionally allowing changes in the setting of working temperature in accordance with environmental changes. From another aspect the applicator 16 is characterised by having a blocking spindle 19 which prevents the emergence of adhesive when it presses on the nozzle 20 and which allows flow to occur when it separates from the nozzle, the spindle being actuated by compressed air acting on one or other face of a piston 21 which forms part of the spindle, and characterised by an empty annular chamber with an outlet 23 to the exterior, between the adhesive chamber and the piston chamber, such that any failure in the seals of the air section or in those of the adhesive section, will allow either the adhesive or the air to escape through the aforesaid outlet, thus giving warning of the failure. A hose of multi-layer construction is disclosed comprising a P.T.F.E. tube reinforced by a metal mesh layer and insulated by a glass fibre tape layer. A further layer is formed by electrical resistors which are held in place by a silicone rubber layer. <IMAGE></p> |
