BLOW-PIPES."
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by James Mallol at the Office of the
Commissioners of Patents on the 18th October 1879.
JAMES MALLOL, of Birmingham, in the County of Warwick.
IN BLOW-PIPES."
"IMPROVEMENTS
The objects of this Invention, which relates to improvements in blow-pipes, will be
rendered apparent in the following description thereof:-
-
In the ordinary form of blow-pipe the air from the bellows and the gas are led to
a common point of issue by concentric pipes, the gas being supplied to the outer one,
and the air to the inner one through flexible tubes. Thus connected the gas is
turned on, the blast is produced by the bellows, and the soldering commences, and
when done the gas is turned off or nearly so.
In soldering many articles it is necessary for the workman to frequently stop
and examine the work in its progress, and at such times there is with the ordinary
blow-pipe a great waste of gas, which goes on burning, it being too troublesome to
turn the gas on or off as many times as is required.
In an improved blow-pipe which has been in use it has been attempted to
remedy this defect, and so long as the work has required only one hand to
manipulate it, so that the other could hold the blow-pipe, the improvements effected
have greatly reduced the consumption of the gas; but when both hands are needed
to manipulate the work, as is often required, the device (only being operative
under a constant pressure of the hand) was (when at such times it was, as is usual,
hung from the soldering pau) inoperative, the desired supply of gas being autom-
atically shut off, so that it was then rendered of less service than the ordinary
blow-pipe, which was, and is still, on this account preferred by many.
The device just referred to consists essentially in the division of the gas chamber
into two chambers, and in the controlling of their communication, which was
effected by the application of a valve which was raised by the depression of a finger
when holding the blow-pipe in the hand, so that the supply of gas was then under
perfect control, it being at other times constantly shut off, there being however at
all times sufficient communication between the gas-chambers as to ensure a small
flame being kept alight at a small independent nozzle adjacent to the large nozzle
at the working end of the blow-pipe, so as to cause an immediate ignition of the
full or augmented supply of gas when admitted thereto by the raising of the
valve.

page_text: "
"
When both hands were required to hold the work when soldering with this
both-pipe, to avoid trouble the workmen frequently tied or wired the lever down,
thus rendering the device inoperative in that economic result for which it was
designed, and engendered carelessness and waste.
The especial object of my improvements is to regulate the supply of the gas to
such blow-pipes, and to have at all times perfect control thereover, so that it can
be caused to issue at any desired rate, and whether held in the hand when but one
hand is required to manipulate the work, or hung by its hook from the soldering
pan when both hands are required for the work.
This result I propose to attain in various ways, of which the following seems to
be the most advantageous:-
To the stem of the valve I adapt an adjustable screwed collar with a milled rim
or periphery, so that upon the lever being depressed the collar can be set so as to
prevent the return of the valve to beyond any desired position, and thereby obtain
any desired opening thereof and supply of the gas, quite irrespective of the blow-
pipe being held in the hand or hung up from the soldering-pan, and so that the
collar can be again set back, and the lever manipulated as usually, when proceeding
with ordinary work.
According to another method I temporarily hold the lever down, and so keep
the valve raised as desired, while the blow pipe is hung up by means of an india
rubber ring, which can be easily slipped onto and off its end as desired. Or again,
I adapt to the main tube of the blow-pipe a hinged or swivelled catch-piece or
staple, which can be turned onto or away from the lever of the valve, and control
'its position as desired.
My Invention also comprises certain improvements in or connected with mouth
blow-pipes.
The ordinary mouth-blow-pipe consists simply of a bent tapered tube, the
smaller end of which is put in the flame, holding the larger end in the mouth and
blowing therethrough, so as to produce a fine jet of blue flame, indicative of
. intense heat.
Others have been made with a mouth piece screwed or rivetted to the broad end
of a tapering nozzle, into which is introduced a pipe which conveys gas to the
common point of issue. In others the conditions have been reversed, the gas
surrounding the inner tube, the air being led to and blown therethrough by means
of a connecting flexible tube.
As regards this part of my Invention, my improvements consist in casting the
mouth-piece and nozzle of one piece, and of such a shape as that the end or point
of issue shall be very small in comparison to the other parts or body of the nozzle,
so as to conduct a minimum of heat thereto, and so that the inner tube can be more
conveniently introduced and soldered than at present, the flexible tubing being
connected thereto. This tube through which the air is blown is very apt to get
charged with saliva, and requires at times to be cleared, but its constant removal from
and replacing in or on the inner tube of the nozzle very soon spoils its end. I
remedy this defect by securing the flexible tubing to a socket which can be at once
screwed onto and removed from the outer end of the said inner tube without any
liability of the flexible tubing getting damaged.
By these improvements I thus produce better and more easily constructed mouth
blow-pipes, more durable, and at less cost than hitherto.