Improvements in or relating to Shaping or Ornamenting Wood and other Yielding Materials by Pressure.
Year: 1898

page_text: Date of Application, 1st Mar., 1898
Complete Specification Left, 1st Dec., 1898-Accepted, 28th Jan., 1899
Improvements in or relating to Shaping or Ornamenting Wood
and other Yielding Materials by Pressure.
I, WILLIAM PHILLIPS THOMPSON, Patent Agent, of Engraved Wood Limited,
Midgehall Street, Liverpool, in the County of Lancaster, do hereby declare the
nature of this invention to be as follows:-
This invention is for improvements on the process described in Patents
No. 435593, 23941%, 12436, 11128%, and has for its object the more efficient
manufacture of panels and the like. I have found in practice that there is very
great difficulty in pressing wood (even when the grain is on end and veneered) to
prevent the surface from cracking and with panels made with the pressure contrary
to the grain it has hitherto been found possible to get only comparatively shallow
impressions and then only by means of heated dies. Further the panels are very
liable to warp.
Now it is to overcome these defects and to obtain better results
and more important effects that this invention is designed. In place of steaming
the panels as set forth in Boult's patent I now saturate or impregnate the surface
with wax, beeswax, paraffine wax or other waxes, greases or oils, and I find in
practice that the combination of several of these is beneficial. Further it is
desirable to use a solvent with them such as oil of turpentine or petroleum spirit.
The waxy material is brought to the liquid state and painted on the veneered wood
blanks preferably very hot and allowed to stand until the solvent has evaporated
prior to pressing. When however wood lengthways of the grain is used I impreg-
nate the wood under pressure or by long steeping with or without artificial heat
in adhesive solutions, then after setting and surface cleaning such as in a sand-
papering machine, I wax the surfaces by rubbing the liquid waxy material over
them. Among the adhesive materials used for the purpose of impregnating wood
lengthways of the grain are solution of glue, gelatine, viscose, or of pyroxyline,
and where it is required to be very thoroughly done I first of all exhaust the air
from the chamber containing the wood producing a high vacuum. I then let in
the solvent and allow it to thoroughly permeate the wood if necessary under pres-
sure or alternately under exhaustion and pressure. When the pores are thoroughly
permeated the surplus liquid is drained off and the wood is open stacked either in
a warm or cool place so as to allow the solvents to partially or wholly evaporate.
Where intense pressure is used, as when for instance the wood is to be pressed so
as to condense it into a hard tough material for carving out objects such as shuttles
and the like it is pressed between the plunger and a die in a containing ring or
open ended box. The containing ring is preferably lightly supported on springs
or counterweights so that as the die and punch approach each other the ring can
move and thus automatically descend or ascend at half the speed of the moving
punch or ram while the pressure is being applied. By this means the friction on
the ring which is very great does not cause as it otherwise would a difference of
density above and below. In the making of panels with a relief on both sides the

page_text: wood has hitherto had to be made extremely thick, namely double the ordinary
thickness. Now in order to avoid this I form the blank when made of cross grained
wood and veneer of at least five layers instead of three, namely, two veneer panels
on the outside a comparatively thin layer say one-quarter to one-eighth of an inch
of wood cut across grain next each panel and then in the centre I place some plastic
material such as rubber, gutta-percha, wood pulp, putty, sawdust and
resin or other adhesive, sawdust and glue, paper pulp and glue,
asphalt, or any other suitable material, in fact almost any material which is
sufficiently of a plastic nature to squeeze out into the required form under pressure.
In this case I form the mould with a raised rim round the field of the die, the two
raised rims come opposite each other and being higher than any other portion press
first on the wood and press the edges of the blank tightly together before any great
pressure conies on the centre. This closes the wood and prevents the plastic
material inside from squeezing out, when then the heavy pressure comes on the
centre the plastic material is forced into those parts where there is least pressure
and presses out the wood, consequently the high reliefs stand out with much less
condensation of the wood than would otherwise take place. This ridge round the
die I find useful in all cases as it confines the wood and prevents it spreading out-
wards, for when the wood is pressed under the two flat dies it squeezes out almost
like dough under great pressure. If however there be a greater pressure on the
outside than any other parts it is held in and not squeezed out. For chair backs
and other articles requiring great strain I find it necessary to embed in the wood
an iron or other strengthening skeleton. In the case of chair backs these are
usually formed with two or more uprights and one or more strong ribs at the back
with thinner material between. I form the moulds accordingly with similar up-
rights and ribs of a horse-shoe form, and form the metal skeleton so as to be enclosed
in these thickened parts, these being the parts with the least pressure. The base of
the skeleton is preferably extended beyond the bottom of the back as a round peg
with a screw thread so that the back can be screwed on to the bottom of the chair.
This makes a strong and at the same time light back and as the skeleton is
embedded in the wood before pressure it is unobservable. In my Patent, No 12436
of 1896, I showed a system of making the moulds. I now find that in place of
electroplating with the pattern in position in the mould itself, it is best to form the
pattern with the field about 1/16 of an inch above the margin and electroplate the
pattern before placing it in the frame or if it is placed in the frame, the frame is
coated with a wax except near the bottom of the box close to the pattern. The field
projects into the frame thus 1/16 of an inch. The pattern is now electro-plated
preferably with an anode about six or eight inches from it in a solution of a tin
salt and a copper salt. The anode can be of bronze from six to ten of tin to 94
to 90 of copper. The electroplate is now tinned and is placed in the iron frame and
backed up with any suitable metal. Where long lengths of pattern are required,
such as in friezes, skirting boards, electric wire covers and the like, I form the die
roller shaped with large bearings and press down by heavy pressure. The blank
is now passed to and fro beneath the die, the pressure being increased at each
passage. For greater ease and manipulation the blank is preferably supported on
a roller immediately below the die. Machines to do this are already well known.
Besides ordinary wood veneer I also use thin sheets of brass, bronze, copper or other
metal. These are veneered to the wood in any desired manner.
Where cross
grained wood is used the wood is preferably made of white soft wood and dyed to
the required colour by either steeping it for a short time in the dye especially in
the vacuum apparatus already described or by being pressed down against a thick
bed, of flannels immersed in the dye.

page_text: Improvements in or relating to Shaping or Ornamenting Wood
and other Yielding Materials by Pressure.
I, WILLIAM PHILLIPS THOMPSON, Patent Agent, of Engraved Wood, Limited,
Midgehall Street, Liverpool, in the County of Lancaster, 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 is for improvements on the process described in Patents
Nos. 435593, 2292%, 23941, 12436, 111829, and has for its, object the more
efficient manufacture of panels and the like. I have found in practice that there
is very great difficulty in pressing wood even when the grain is on end and veneered
to prevent the surface from cracking and with panels made with the pressure
contrary to the grain it has hitherto been found possible to get only comparatively.
shallow impressions and then only by means of heated dies. Further the panels
are very liable to warp. Now it is to overcome these defects and to obtain better
results and more important effects that this invention is designed. In place of
steaming the panels as set forth in Patent No. 43553 I now saturate or impregnate
the surface with wax, beeswax, paraffin wax or other waxes, greases or oils, and
I find in practice that the combination of several of these is beneficial. Further
it is desirable to use a solvent with them such as oil of turpentine or petroleum
spirit. The waxy material is brought to the liquid state and painted on or rubbed
over the veneered wood blanks preferably very hot and allowed to stand until the
solvent has evaporated and the waxy material substantially absorbed prior to press-
ing. When however wood lengthways of the grain is used I impregnate the wood
under pressure or by long steeping with or without artificial heat with adhesive
solutions then after setting and surface cleaning such as in a sandpapering machine
I wax the surfaces by rubbing the liquid waxy material over them. Among the
adhesive materials used for the purpose of impregnating wood lengthways of the
grain are solution of glue, gelatine, viscose, or of pyroxyline, and where it is
required to be very thoroughly done I first of all exhaust the air from the chamber
containing the wood producing a high vacuum.
I then let in the solution and
allow it to thoroughly permeate the wood if necessary under pressure or alternately
under exhaustion and pressure. When the pores are thoroughly permeated the
surplus liquid is drained off and the wood is open stacked either in a warm or cool
place so as to allow the solvents to partially or wholly evaporate. A good solution
for this purpose is viscose (mercerised cellulose) dissolved in bisulphide of carbon
1 part, beeswax one part, paraffin wax one part, and a variable amount of solvent
such as acetone spirits of turpentine or alcohol, more solvent and less waxes being
required for woods with fine pores than for woods with coarse pores and for large
thick pieces of wood than for small or thin pieces and when low pressures are used
than when high are employed. The quantity of paraffin can also be reduced or
eliminated. Where intense pressure is used, as when for instance the wood is to
be pressed so as to condense in into a hard tough material for carving out objects
such as shuttles and the like it is pressed between the plunger and a die in a con-
taining ring or open ended box. The containing ring preferably lightly sup-
ported on springs or counterweights so that as the die and punch approach each
other the ring can move and thus automatically descend or ascend at half the speed
of the moving punch or ram while the pressure is being applied. By this means
the friction on the ring which is very great does not cause as it otherwise would
a difference of density above and below. In the making of panels with a relief
on both sides the wood has hitherto had to be made extremely thick, namely double
the ordinary thickness. Now in order to avoid this I form the blank when made

page_text: of cross grained wood and veneer of at least five layers instead of three, namely,
two veneer panels on the outside a comparatively thin layer say one-quarter of an
inch of wood cut across grain next each veneer panel and then in the centre I place
some plastic material such as rubber, gutta-percha, wood pulp, putty, sawdust
and resin or other adhesive, sawdust and glue, paper pulp and glue, asphalt, or
any other like suitable material, in fact almost any material which is sufficiently
of a plastic nature to squeeze out into the required form under pressure and yet
set hard. In this case I form the mould with a raised rim round the field of the die,
the two raised rims come opposite each other and being higher than any other
portion press first on the wood and press the edges of the blank tightly together
before any great pressure comes on the centre. This closes the wood and prevents
the plastic material inside from squeezing out, when then the heavy pressure comes
on the centre the plastic material is forced into those parts where there is least
pressure and presses out the wood, consequently the high reliefs stand out with
much less condensation of the wood than would otherwise take place. This ridge
round the die I find useful in all cases as it confines the wood and prevents it
spreading outwards, for when the wood is pressed under the. two flat dies it squeezes
out almost like dough under great pressure. If however there be a greater pressure
on the outside than any other parts it is held in and not squeezed out. In place
of this ridge I may as hereafter described for chair backs confine the plastic material
by a ring of wire or like material which acts as a strengthening skeleton to the
panel. For chair backs and other articles requiring great strain I find it necessary
to embed in the wood an iron or other strengthening skeleton. In the case of
chair backs these are usually formed with two or more uprights and one or more
strong ribs at the back with thinner material between. I form the moulds accord-
ingly with similar uprights and ribs of a horse-shoe or other suitable form, shape
in the main design and form the metal skeleton so as to be enclosed in these
thickened parts, these being the parts with the least pressure. The base of the
skeleton is preferably extended beyond the bottom of the back as a round
peg with
a screw thread so that the back can be screwed on to the bottom of the chair; an
illustration of this is shown in the drawing. This makes a strong and at the same
time light back and as the skeleton is embedded in the wood before pressure it is
unobservable. In my Patent, No. 12436 of 1896, I showed a system of making the
moulds. I now find that in place of electroplating with the pattern in position
in the mould itself, it is best to form the pattern with the field about 1/16 of an
inch above the margin and electroplate the pattern before placing it in the frame
(or if it be placed in the frame first, the frame is coated with a
wax except near the bottom of the box close to the pattern). The
field projects into the frame thus 1/16 of an inch. The pattern is
now electro-plated preferably with
an anode about six or eight inches
from it in a solution of a tin salt and a copper salt or in a nickel plating solution.
The anode can be of bronze from six to ten of tin to 94 to 90 of copper, or of nickel
as the case may be. The electroplate is now tinned and if not formed in the frame
is placed in the iron frame and backed up with any suitable fusible metal. Where
long lengths of pattern are required, such as in friezes, skirting boards, electric
wire covers and the like, I form the die roller shaped with large bearings and press
down by heavy pressure. The blank is now passed to and fro beneath the heated
die, the pressure being increased at each passage. For greater ease and manipula-
tion the blank is preferably supported on a roller immediately below the die.
Machines to do this are already wellknown. In regard to these friezes and skirt-
ing boards and panels erected in the wainscotting, dados, etcetera of new houses
I find it necessary or beneficial to make the backs of the panels waterproof by using
metal asphalt or other impervious backing instead of ordinary veneer and even
for the face, in some cases besides ordinary wood veneer I also use thin sheets of
brass, bronze, copper or other metal. These are veneered to the wood in any desired
manner. Where cross grained wood is used this is preferably of corresponding
colour to the veneer or of white soft wood and dyed to the required colour by steep-

page_text: ing it for a short time in the dye especially in the vacuum apparatus already
described.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In the manufacture of pressed wood panels and the like impregnating the
surface of the wood with waxy material before pressing substantially as described.
2. Impregnating the wood before pressing with an adhesive solution substantially
as described by first exhausting the air from the pores, then applying the solution
allowing it to nearly set and pressing or rolling substantially as described.
3. Pressing wood in a free ring between two plungers or dies whereby only one
pressure cylinder can be used and vet both surfaces be pressed evenly.
4. The formation of panels with a central plastic material and wooden exterior
and means for strengthening such panels and preventing the exuding of the plastic
material substantially as described.
5. The manufacture of pressed wood chair backs with strong internal skeleton
substantially as described.
6. The improvement in the manufacture of electroplate surfaced dies substan-
tially as herein described.
7. The manufacture of pressed wood panels and the like with one or both faces
of metal or its equivalent as described whereby the appearance of beaten metal is
obtained or the backs of the panels are made absolutely impervious to moisture for
the purposes described.
1000
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham and London.
TO
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