Active flashback arrestor for use with head of a torch

[0032]In accordance with the first embodiment of the present invention, an internal valve plug 29 and preferably also an internal porous structure 30 are within a common interior chamber of the cutting tip 20 for restricting flashback from passing through the cutting tip, as will be discussed in greater detail below. The valve plug 29 and porous structure 30 are hidden from view in FIG. 1 and are therefore illustrated by broken lines. Each of the valve plug 29 and porous structure 30 are preferably coaxial with each of the inner and outer parts 24, 26. The cutting tip 20 is preferably removably mounted to the head 22 in a conventional manner by an externally threaded nut 32 (FIG. 1), as will be discussed in greater detail below.

[0033]As best understood with reference to FIG. 1, the head 22 includes an interior surface that extends around an axis to define a composite cavity 34 that is open at the lower end of the head. The interior surface of the head 22 includes annular upper and lowe

[0059]In accordance with the second embodiment of the present invention, the adapter 20′ and cutting tip 110 include coaxial annular channels that face and are open to one another to form an annular chamber 122 that encircles and is coaxial with the oxygen passageways 58, 98. The annular chamber 122 is completely closed, except for being open to the outlets of the downstream fuel passageways 78 and inlets of the terminal fuel passageways 120. The outlets of the terminal fuel passageways 120 are at the lower end of the cutting tip 110.

[0060]In accordance with one example of the second embodiment of the present invention, the adapter 20′ is mounted to the head 22 (FIG. 1) and functions just like the cutting tip 20 of the first embodiment of the present invention, except that the oxygen and fuel are discharged out of the nozzle of the cutting tip 110. Additionally, if the cutting tip 110 becomes damaged, it can be advantageously replaced with a new one while the adapter 20′ remains mounte