Improved Means for Heating Metal Rods, Bars, or Wires in Machinery for making Nails, Screws, Keyblanks, Fileblanks, and other articles therefrom.
Year: 1891

page_text: Date of Application, 12th May, 1891
Complete Specification Left, 21st Jan., 1892-Accepted, 27th Feb., 1892
PROVISIONAL SPECIFICATION.
Improved Means for Heating Metal Rods, Bars, or Wires in
Machinery for making Nails, Screws, Keyblanks, Fileblanks,
and other articles therefrom.
We, SIEMENS BROTHERS & Co., LIMITED, of 12 Queen Anne's Gate, West-
minster, in the County of Middlesex, and ALFRED DAVID WILLIAMSON, of
26 Alwyne Road, Canonbury, in the County of Middlesex, Electrical Engineers,
do hereby declare the nature of this invention to be as follows:-
This invention has for its object to enable a metal rod, bar or wire that is being
fed through a machine for making nails, screws, key blanks, and the like therefrom,
to be heated to a high degree by electricity at a part thereof in close proximity to
the place where the rod or bar is to be operated upon by the tools.
According to this invention the rod or bar is passed through or in close
contiguity to a body or bodies which is or are heated to incandescence by an
electric current, so that as the rod or bar travels forward, it becomes heated
thereby to the requisite high degree for enabling it to be operated upon by the
tools. For this purpose there is provided at such part of the machine a block or
cylinder of carbon or other suitable material which forms part of an electrical
circuit through which a sufficiently powerful current is passed to heat the block or
cylinder to incandescence.
This block or cylinder is formed with a passage through it of sufficient size to
allow the metal rod or bar to pass through without touching it, and guide plates or
glands of insulating material, such as slate, are by preference provided at the two
ends of the tubular block or cylinder, having holes through them of a size sufficient
to allow the rod or bar to pass through, so as to hold this in the required central
position in the said passage, and prevent the rod or bar from short-circuiting the
current.
The block or cylinder is made of such a length that the rod or bar in passing
through the same at the speed required by the particular manufacture carried on,
will, at its exit, have attained the required degree of heat.
For conveying the electric current through the block or cylinder from and to the
circuit, the ends thereof are preferably clamped between metal jaws formed to
make contact with more or less the entire outer surface of the cylinder, and secured
by screws, cams or wedges, so that when the cylinder has become wasted away by
use, the jaws are released and the cylinder replaced by a new one. The jaws are
suitably connected to the conductors of the circuit.
For preventing the wasting away of the block or cylinder, this may be glazed
internally and externally with suitable fire resisting material, and to prevent loss of
heat by radiation the block or cylinder may be covered with a non-conducting
sheathing of asbestos, slagwool, or other suitable material.
In order to prevent any injurious oxidation of the rod or bar when heated to a
high degree within the cylinder, the space within the latter may be kept filled with
hydrocarbon vapour or other neutral gas supplied through a pipe.
Instead of using a solid block or cylinder this may be built up of two or more
parts suitably connected together, or a helically coiled carbon bar might be used.
Dated this 12th day of May 1891.
ABEL & IMRAY,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improved Means for Heating Metal Rods, Bars, or Wires in
Machinery for making Nails, Screws, Keyblanks, Fileblanks,
and other articles therefrom.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate, West-
minster in the County of Middlesex, and ALFRED DAVID WILLIAMSON of
26 Alwyne Road, Canonbury, in the County of Middlesex, Electrical Engineers
do hereby declare the nature of this invention and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention has for its object to enable a metal rod bar or wire that is being
fed through a machine for making nails, screws, keyblanks or the like to be heated
electrically to a high temperature, in close proximity to the tools which are to
operate on the heated metal.
For this purpose an electrical heating appliance is arranged as described with
reference to the accompanying drawings. Fig. 1 is a longitudinal section and
Fig. 2 is a transverse section of X X of Fig. 1; Fig. 3 is an end and Fig. 4 is a
plan.
A is a tube of carbon which may be as shewn externally circular and internally
of a shape corresponding with that of the metal rod or wire B that is to be heated
it may be made in one piece or built up of segments. Its ends are externally coned
to receive coned sleeves C C¹ of copper gun metal, brass or other metal which is a
good conductor of electricity and within the ends are fixed pieces D D¹ of slate,
kaolin or other suitable refractory material to act as guides for the rod B passing
through them. The sleeves C C are fitted in frames E E¹ the one frame E being
stationary and the other E¹ free to slide along guide bolts F which are fixed to E
and to a third stationary frame E. Springs & attached to insulators H, which
may be of porcelain, draw the frame E' towards E and thus cause the sleeves C C
to closely embrace and make good electrical contact with the ends of the carbon
tube A. A box made in two parts K K of which K is attached to E and K to E¹
contains slagwool sand or other suitable refractory material that is a bad conductor
of heat, completely surrounding and enclosing the tube A and covered by a remove-
able cover M. The various parts are insulated from each other by mica or other
suitable nonconducting refractory material as indicated by the black parts of the
drawing, so that when the frames E El are connected respectively by conductors L L
to the terminals of a dynamo electric machine or other source of electricity the
electric current, which may be of moderate tension but is large in quantity must
pass exclusively through the carbon tube A. heating it to a high temperature.
The heat of the tube radiated on the rod or wire B raises it to a high temperature
and as this rod or wire is advanced step by step to be operated on by hammers or
other tools, it issues hot from the front end of the tube at D near which point the
operating tools may be arranged. The tube A instead of being of carbon may be
of other refractory material or compound of low electrical conductivity. The
interior of the tube may be glazed to prevent it from wasting away, and besides the
bed of sand or the like which it occupies within the box K K' it may be sheathed
with asbestos slag wool or such like material.
.
For the springs G may be substituted wire cords passing over pullies and
attached to suitable weights; and instead of fitting the coned ends of the tube
with coned sleeves pressed on them as described, these ends might be held in
conducting clamps of any known kind such as are used, for example, in holding
pieces of metal when they are being electrically welded together.
"
The interior of the tube might by means of a pipe leading into it laterally, be
kept supplied with hydrocarbon vapour, nitrogen or other gas of neutral character
so as to avoid injurious oxidation of the metal rod or wire passing through the
tube.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what
we claim is:-
1. The herein described method of heating a metal rod, bar or wire that is being
fed to a nail making or other like machine, by causing it to pass through an
electrically heated tube of carbon or other material of low electrical conductivity.
2. The apparatus for heating electrically a metal rod bar or wire, substantially as
described with reference to the accompanying drawings.
Dated this 21st day of January 1892.
ABEL & IMRAY,
Agents for the Applicants.