Improvements in the Manufacture of Seamless Tubes or Conduits for Electrical and other Purposes and in the Apparatus employed therein.
Year: 1891

page_text: Date of Application, 2nd Apr., 1891
Complete Specification Left, 2nd Feb., 1892-Accepted, 2nd Apr., 1892.
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Seamless Tubes or Conduits for
Electrical and other Purposes and in the Apparatus employed
therein.
I, JAMES RAPER THAME of 4 St. Mary Axe in the City of London,
Mechanical Engineer do hereby declare the nature of this invention to be as
follows:-
This invention relates to the manufacture of seamless tubes or conduits for
electric light, telegraph and telephone and other mains or wires also applicable for
conveying gas, water, petroleum or other fluids and liquids and other purposes.
In the manufacture of these tubes or conduits, I take pulp prepared from any
suitable raw material or waste which I mould into a sheet or sheets of the desired
shape and thickness preferably leaving the edges splayed or tapered and in
moulding the said sheet I arrange the pressure applied so that the middle of the
sheet receives more than the splayed or tapered edges.
After having made the sheet in this manner I place the same on a "felt" or
"wire" or like device and bend the whole round a mandril of the right diameter.
The mandril used may be a rod of polished metal, but is preferably a tube slit
from end to end longitudinally, this tube may be furthermore perforated, and
covered with a fine wire strip or sheet of reticulate material the edges of the said
wire strip or sheet being passed in or through the slit cut in the tube, by this means
the water contained in the pulp sheet is enabled to get away freely from all parts
of the said sheet of pulp while under pressure.
Having wrapped the sheet of pulp around the mandril with the splayed or
tapered edges of the pulp sheet overlapping each other the carrying wire or felt is
next wrapped around the bent pulp sheet and the whole is then transferred and
pressed into a suitably constructed mould.
The tube so made is afterwards dried in a suitable drying apparatus.
The tubes or conduits having been thoroughly desiccated, I render the same
more or less as waterproof as possible and at the same time give it a high insulation
by immersion in a bath containing a liquid hydrocarbon which may have approxi-
mately the formula CHO in combination with asphaltum, bitumen, stearine-
pitch or other suitable solid hydrocarbon or hydrocarbons,
When necessary for fireproof purposes I combine with the pulp any suitable
fireproof material such as ground slate, silica, barium-sulphate, asbestos or
similar material.
The waterproof and highly insulating tubes or conduits so prepared are where
necessary such as for laying under ground incased in suitable metallic tubes leaving
a space between the insulating and the metallic tubes said space being filled with a
suitable material possessing high insulation and sufficient strength.
The tubes so prepared are preferably joined together by means of a nut or socket
said nut or socket having a right hand thread cut at one end and a left hand thread
cut at the other the middle of said nut internally being chambered to ensure perfect
contact of the two ends of the tubes or conduits which have corresponding threads
on their ends, moreover the ends of the tubes or conduits are formed of external
or internal cone shape respectively to ensure perfect continuity and to prevent
leakage, or pipes so made can be joined together in any well known way such as
with a cap and lining, bayonet joint, union, etcetera.
Dated the 2nd dare of Anvil 1901
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Seamless Tubes or Conduits for
Electrical and other Purposes and in the Apparatus employed
therein.
I, JAMES RAPER THAME of 2 Waters Mill, Boxmoor, formerly of 4 St. Mary
Axe, in the City of London, Mechanical Engineer 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 relates to the manufacture of seamless tubes or conduits for
electric light, telegraph and telephone and other mains or wires also applicable for
conveying gas, water, petroleum, or other fluids and liquids and other purposes.
In the manufacture of these tubes or conduits, I take pulp prepared from any
suitable raw material or waste which I mould into a sheet or sheets of the desired
shape and thickness leaving the edges splayed or tapered and in moulding the said
sheet I arrange the pressure applied so that the middle of the sheet receives more
than the splayed or tapered edges.
"wire
י,
After having made the sheet in this manner I place the same on a
"felt" or
or like device and bend the whole round a mandril of the right diameter.
The mandril used may be a rod of polished metal, but is preferably a tube slit
from end to end longitudinally, this tube may be furthermore perforated, and
covered with a fine wire strip or sheet of reticulate material, the edges of the said
wire strip or sheet being passed in or through the slit cut in the tube, by this
means the water contained in the pulp sheet is enabled to get away freely from all
parts of the said sheet of pulp while under pressure.
Having wrapped the sheet of pulp around the mandril with the splayed or
tapered edges of the pulp sheet overlapping each other the carrying wire or felt is
next wrapped around the bent pulp sheet and the whole is then transferred and
pressed into a suitably constructed mould..
The tubes so made are afterwards dried in a suitable drying apparatus, and may
next be passed through a rolling mill to render them smooth and true. Straight
lengths will bend if placed in slanting positions under higher temperatures, to any
required degree of curved elbow or bend.
The tubes or conduits having been thoroughly desiccated, I render the same
more or less as waterproof as possible, and at the same time give it a high insula-
tion by immersion in a bath which may be prepared from a liquid such as creosote
"dead or "green"oil, in combination up to saturation with asphaltum, bitumen,
stearine, pitch, or other suitable solid hydrocarbon or hydrocarbons.
29
When necessary for fire proof purposes I combine with the pulp any suitable
fire proof material such as ground slate, silica, barium, sulphate, asbestos or similar
material.
The waterproof and highly insulating tubes or conduits so prepared are where
necessary such as for laying under ground encased in, suitable metallic tubes
leaving a space between the insulating and metallic tubes said space being filled
with a suitable material possessing high insulation and sufficient strength.
The tubes so prepared are preferably joined together by means of a nut or
socket, said nut or socket having a right hand thread cut at one end and a left
hand thread cut at the other, the middle of said nut internally being chambered
to ensure perfect contact of the two ends of the tubes or conduits which have
corresponding threads on their ends, moreover the ends of the tubes or conduits
are formed of external or internal cone shape respectively to ensure perfect
continuity and to prevent leakage, or pipes so made can be joined together in
any well known way such as with a cap and lining, bayonet joint, union, etcetera.
And in order that my invention may be the better understood I now proceed to
describe the same in relation to the drawings hereto annexed.

page_text: Figure 1 is a vertical section through the mould in which the pulp is pressed
into sheets with splay edges.
Figure 2 is a section of a hollow mandril upon which the tube is formed and
pressed.
Figure 3 shows the manner in which a pitch composition is applied between a.
pulp inner tube and an outside iron tube.
Figure 4 is a transverse section through 1-2 on Figure 3 to show the extension
piece.
Figure 5 is a longitudinal section through a joint between two covered pulp.
tubes.
In preparing the pulp for making into a tube a sheet of suitable length is placed
in a trough mould A which is provided with a slatted or open frame bottom B
covered with perforated gauze or metal sheet C. The upper part of the trough
mould is filled with three plungers D, D', D, each receiving pressure through
distinct springs E, E, E, from a single plunger or piston F. The centre spring E'
is stiffer than the outer springs E, E, so that the centre portion of the sheet of pulp.
is exposed to greater pressure than the splayed edges under the side plungers D D.
The piston or plunger F may be operated by hydraulic or mechanical pressure of
any convenient kind.
The splay edges of the sheet are made of such a contour that when they are
brought together to form a tube they will lap and give a similar section or thickness.
to the lapped joint as corresponds to the rest of the tube.
The preferable form of mandril I employ for forming the tube thereon is shown
at Figure 2 and consists of a split tube G perforated with holes and covered with a
sheet of reticulate or gauze material, the edges of which are passed into the tube
through the slit H. and are fixed in position by a wedge or strip driven into the
slit. Thus any water or moisture from the pulp sheet that is wrapped around this
mandril escapes easily through the centre of the tube.
When the splayed pulp sheet has been wrapped around this mandril it is.
covered by an external wire gauze or felt sheet and the whole is pressed in
a suitable circular or cylindrical mould divided into two halves or suitable.
segments.
The tubes so made are afterwards dried in a suitable drying oven or chamber
and may next be passed through a rolling mill to render them smooth and true.
The tube is then rendered waterproof and given a high degree of insulation as
before described.
Where the tubes are designed for laying underground for conduits for electrical
mains and leads I prefer to encase them in metallic (say iron) tubing leaving a
space between the pulp tube K Figure 3 and the metallic tube L into which a
filling of pitch or other fluid material possessing a high insulation and sufficient.
strength. A convenient method for carrying out such filling is shown in Figure 3.
The inner pulp tube K is supported in the outer tube by distance pieces M which
will hold the tubes in position and yet allow the fluid filling to pass. A hole / for
pouring in the fluid filling is pierced through the metallic tube L and air ventilation
holes are also provided to allow the escape of air, the ends being temporarily
stopped by washers.
In Figure I show a convenient method of joint between two tubes one end of
a tube K being provided with a male coned projection N and the other end with
a female coned socket N to suit and fit the cone projection.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1st. A process and apparatus used therein for making tubes of any desired
section by pressing loosely knitted pulp or half stuff in the form of a sheet with
splayed edges to form when. bent and pressed upon a hollow perforated mandril

page_text: with an outer detachable reticulated covering a tube of uniform section even where
the splay edges lap.
2nd. The treatment of tubes made of pulp or half stuff after being dried with a
liquid such as creosote, dead, or green oil in combination with a solid hydrocarbon,
such as stearine or other pitch, bitumen or asphaltum to give them permanent high
insulation.
3rd. The treatment of tubes made of pulp or half stuff with heated paraffine or
ozokerit wax with or without a liquid hydrocarbon.
4th. A tube of any section made of a sheet of pulp or half stuff with the
splay edges lapped on one another and united by pressure to form a homo-
geneous tube of even section throughout and with or without ends formed in a male
cone and female cone socket respectively to form joints with other such tubes,
substantially as described.
5th. The combination of a pulp or half stuff' tube with an external larger metal
tube, the space between being filled with bitumen, wax, pitch, resin, or similar
insulating material, substantially as described.
Dated 1st day of February 1892.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.