AN IMPROVED METHOD OF, AND FURNACE FOR, HEATING FILES AND SIMILAR TOOLS FOR HARDENING
Year: 1885

page_text: I MAURICE HAGUE N° 11 Garden Street Sheffield in the County of York File
Cutter do hereby declare the nature of my said invention for AN IMPROVED
METHOD OF, AND FURNACE FOR, HEATING FILES AND SIMILAR TOOLS FOR
HARDENING to be as follows:-
My invention relates to an improved method of heating files and other similar
tools preparatory to hardening them, and in the construction of the furnace used
for such purpose, the object being to enable such process of heating files to be more
rapidly and effectively performed than it is at the present time.
It is usual to beat files preparatory to hardening them, either by placing them
in a vessel of molten lead, or in a hearth fire, the former cannot be depended upon,
to heat the file equally, and the latter is equally unreliable; the teeth of the files
also get damaged being pushed into the coke in hearth fires.
Now in carrying out my invention I build a furnace of peculiar construction so
that the heat is directed upon the files where it is most required, that is upon the
thickest parts.
I construct my improved furnace with the firing hole in the centre or thereabouts,
underneath the furnace proper, and I carry the flue to the right and left so as to
enter the furnace at each end, the exit flue being made over the centre of the
furnace. I prefer to make the floor of such furnace of iron bars placed close
together, upon which may be laid a layer of coke, to place the files upon.
The Files are laid in the furnace pointing from the front to the back, and it
follows that the flame from the fire entering at each end of the furnace, and been
drawn to the exit in the centre, the body of heat passes over the central part of the
files and a more moderate heat over the points, and tangs of the files.
My construction of furnace enables more files to be heated at one time in a
proper manner, and without so much risk of being burnt, and therefore a workman
can turn out more work in the same time, than by the ordinary methods in use..
Dated thath daf 100%
ROBT F. DRURY,
Agent for the Applicant...

page_text: COMPLETE SPECIFICATION.
I MAURICE HAGUE N° 11 Garden Street, Sheffield in the County of York File
Cutter do hereby declare the nature of my invention for AN IMPROVED METHOD
OF, AND FURNACE FOR HEATING FILES AND SIMILAR TOOLS FOR HARDENING, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, that is to say:-
My invention relates to an improved method of heating files and other similar
tools preparatory to hardening them, and in the construction of the furnace used
for heating such tools, the object being to render such process capable of being
more rapidly and effectively performed, than is possible by the means at present
in use.
The usual plan of heating files for the purpose of hardening is to put them either
into an ordinary hearth fire, or into a vessel of molten lead, heated to a suitable
degree, in the first plan the teeth of the unhardened file are very liable to be
damaged by the coke, and the heating is not regular, in the latter the heating is
also unreliable, and the method is costly.
In carrying out my invention, I build a furnace of peculiar construction in which
the heat or flame from the fire is directed upon, and made to pass over, the files or
other similar tools, so that the thickest parts shall be subject to the greatest heat.
And in order that my invention may be fully understood, I annex bereto a sheet
of drawings to show the construction of the furnace.
I construct my improved furnace with the firing hole A in a central position
underneath the furnace B, and I carry a flue C to the right, and another D, to the
left, so that the flame and heat will enter the furnace at each end, passing over
a low bridge E (which may be of any suitable height to suit the work,) then across
the files or other articles F, and finally up the flue or chimney G, which is built
over the centre of the furnace.
I prefer to make the floor H, of iron bars placed close together, and covered with
a thin layer of coke, upon which the files Fare laid pointing from back to front.
I is the furnace door, J is a balance weight, K is the firing door, L are the fire bars.
The construction of the furnace as hereinbefore described causes the bulk of the
beat to be drawn over the centre or thickest parts of the files and a more moderate
heat over the points and tangs.
The use of my improved construction of Furnace enables more files to be heated
at one and the same time, in a satisfactory manner, without so much risk of being
burnt, than can be accomplished by the various methods now in use.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same may be performed, I declare that what
I claim is
1st The improved method of heating files and other similar tools, by causing the
heat of a furnace to pass over them from both right and left hand, to a centre flue
as hereinbefore described.

page_text: 2nd The construction and use of Furnaces for the purpose specified, in which the
flame and heat is brought in from both sides and passes out at a centre flue,
substantially as herein before described and illustrated.
ROBT F. DRURY,
Agent for the Applicant.