Blow torch, a blow torch nozzle and a swirler for a blow torch nozzle

Abstract

A blow torch nozzle ( 10 ) having a swirler ( 26 ) which is bounded by a generally cylindrical shape ( 42 ). The swirler ( 26 ) a passageway ( 28, 40 ) extending through it defined by a wall surface of the swirler ( 26 ). A part of the wall surface extends at an angle to the axis of the nozzle ( 10 ) to impart a rotary motion to gases which pass through the swirler ( 26 ) in use. The wall surface opens out onto a side of the swirler ( 42 ) so the wall surface defines a recess ( 28, 40 ) extending inwardly from the side of the swirler ( 26 ). The swirler ( 26 ) may be provided with a short tube or ring ( 50 ) which surrounds the swirler ( 26 ) and has ends which are substantially flush with those of the swirler ( 26 ). The swirler ( 26 ) may be held within the tube or ring ( 50 ) by means of an interference fit.

1 . A blow torch nozzle having a swirler within it which swirler is bounded by a generally cylindrical shape and which swirler has at least one passageway extending through it defined at least in part by a wall surface of the swirler at least a part of which wall surface extends at an angle to the axis of the nozzle so as to impart a rotary motion to gases which pass through the swirler when the blow torch is in use, in which the wall surface opens out onto a side of the swirler in such a manner that the wall surface defines a recess extending inwardly from the side of the swirler. 
     
     
         2 . A blow torch nozzle according to  claim 1 , in which the swirler comprises a replaceable component of the blow torch nozzle. 
     
     
         3 . A blow torch nozzle according to  claim 1 , in which the swirler has a plurality of such passageways, for example four. 
     
     
         4 . A blow torch nozzle according to  claim 1 , in which side surfaces of the swirler and each wall surface of the or each passageway may be such that they are generated, in a mathematical sense, substantially by edges of one of the end surfaces of the swirler as it is moved axially along the swirler to the other end thereof, and rotated as it is so moved, the movement and the rotation being at a substantially uniform rate. 
     
     
         5 . A blow torch nozzle according to  claim 4 , in which the angle of such rotation from one end of the swirler to the other is substantially 45 degrees. 
     
     
         6 . A blow torch nozzle according to  claim 1 , in which the swirler is provided with a cylindrical ring which surrounds the swirler, and is secured thereto, for example by swaging. 
     
     
         7 . A blow torch nozzle according to  claim 6  in which the swirler is held within the ring by means of an interference fit. 
     
     
         8 . A blow torch nozzle according to  claim 6 , in which the ends of the swirler are substantially flush with the ends of the ring. 
     
     
         9 . A blow torch nozzle according to  claim 1 , in which the nozzle comprises two tubular parts connected together by respective screwthreads of those parts so that those parts have a common axis, those parts having respective internal shoulder portions between which the swirler or the ring thereof is held. 
     
     
         10 . A blow torch nozzle having a swirler within it which swirler is bounded by a generally cylindrical shape and which swirler has at least one passageway extending through it defined at least in part by a wall surface of the swirler at least a part of which wall surface extends at an angle to the axis of the nozzle so as to impart a rotary motion to gases which pass through the swirler when the blow torch is in use, in which in any and every cross-section of the nozzle that includes the swirler, the said wall surface is generally U-shaped or arcuate, and the said at least one passageway is also defined on its outerside by a part cylindrical surface of the swirler which is everywhere at a substantially uniform distance from an outer cylindrical surface of the swirler. 
     
     
         11 . A blow torch having a nozzle as claimed in  claim 1 . 
     
     
         12 . A swirler for a blow torch nozzle having the features of the swirler as set out in  claim 1 .