IMPROVEMENTS IN PREPARING WOOD TO PREVENT ITS WARPING OR SHRINKING
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CLAUDE
FRANÇOIS TACHET, of Paris, in France, Mathematical Instrument Maker, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent, under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fifteenth day of
November One thousand eight hundred and fifty-one, in the fifteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Claude François Tachet, my exors, adñiors, and assigns, Her especial
licence, full power, sole privilege, and authority, that I, the said Claude
François Tachet, my exors, adññors, and assigns, or such others as I, the said
Claude François Tachet, my exors, adiñors, or assigns, should at any time
agree with, and no others from time to time, and at all times during the term
of years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, and in
the Islands of Jersey, Guernsey, Alderney, Sark, and Man, and in all Her
Majesty's Colonies and Plantations abroad, my Invention of "IMPROVEMENTS IN
PREPARING WOOD TO PREVENT ITS WARPING OR SHRINKING;" in which said
Letters Patent is contained a proviso, that I, the said Claude François Tachet,
shall cause a particular description of the nature of my said Invention, and in

page_text: what manner the same is to be performed, by an instrument in writing under
my hand and seal, to be inrolled in Her said Majesty's High Court of Chancery
within six calendar months next and immediately after the said in part
recited Letters Patent, as in aud by the same, reference being thereunto had,
will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Claude François Tachet, do hereby declare that the nature of my said Inven-
tion, and in what manner the same is to be performed, are fully described and
ascertained in and by the following description thereof, reference being had to
the Drawings, in which the same letters of reference represent different parts,
that is to say:-
One of the methods hitherto resorted to for preventing wood from warping
or shrinking consisted in superposing sheets of wood with their fibres set in
opposite directions, either perpendicularly, diagonally, or horizontally, accord-
ing as the particular application required, the adherence between the surfaces
being obtained by means of glutinous paste in a state of fusion. This method
however has proved unsuccessful to attain the desired result, inasmuch as the
wood and glue dilate together upon mere exposure to an humid atmosphere,
and that upon their exposure afterwards to a warm or dry atmosphere, the
wood being impeded in its contraction, by the opposite tensions of the sheets
composing the board, becomes undulated and disjointed.
Now, observation has led me to discover that when an adhesive or imper-
vious matter was employed in a state of fusion for joining together sheets or
pieces of wood, the said matters were subject to soften and to give way even
at a moderate heat of the atmosphere.
And my improvements consist in applying the adhesive substance in a state
of powder between the sheets or pieces of wood to be united, and in softening
and fusing the impervious and gluey matter, afterwards by transmitting heat
through the thickness of the wood, which I effect by means of the apparatus,
and in the manner herein-after described. With this mode of operating I
prepare boards composed of two or many sheets of wood, which sheets may be
of any required thickness and of different thicknesses for the same board.
DESCRIPTION OF THE DRAWINGS.
Drawing 1, Figure 1 is a longitudinal elevation of the machinery for press-
ing the sheets of wood to be glued, and for transmitting heat for dissolving the
glue; Figure 2 of the same Drawing is an end elevation of the same machine.
The fusing apparatuses A, are in the form of flat boxes or drawers made of

page_text: sheet iron and set at a distance of about one inch from each other, by means
of longitudinal iron bands a, a, a, adherent to the iron boxes. The proportions
of the surface of these cases can be made of the size of the board to be pro-
duced, two of these cases or drawers A, A, Figure 1, Drawing 1, united form a
complete apparatus. It opens and shuts at will by means of binges, as repre-
sented at B, B, Figure 2, which are adjusted by the screws B', B', Drawing 1.
When the apparatus is open, that is to say, when I set the upper part in a
vertical position, after powdering the sheets of wood, 1 place them on the part
of the apparatus which remains in a horizontal position, and then I shut the
part which was left open. I must observe that the hinges B, B, Figure 1,
and the screws C, Figure 2 which are placed on the edge facing the hinges
serve to raise at will, and to support when raised, the upper part of the
apparatus at a greater distance than the thickness of the sheets of wood which
are to be pressed. When I lower that part I keep it suspended at some
distance from the sheets of wood, and then, by means of the screws of the
hinges and of those in front C, 1 cause it to be gradually lowered as far as the
wood, such precaution being necessary to avoid the powder from getting out of
its proper position, and enable me to make sheets of wood of every thickness.
The whole of the apparatus is set on the traverse wooden beams D, D, Figures
1 and 2, united by means of bars E of the same Figure, which maintain them
at equal distances and form a kind of frame which is set on two longitudinal
beams or shafts of wood F, Figure 1. In the centre underneath I adapt an
axletree G which is supported by a cast-iron standard H by means of which
the whole of the apparatus is made to oscillate similarly to a piece of ordnance
on its carriage, the whole moves on cast-iron rollers I, I, travelling on iron
rails. When I have disposed the sheets of wood and shut the apparatus as
herein-before described I tighten by means of strong presses J, J, the
extremities of the cross pieces D, D, and 1 then cause the whole to be lowered
at one end, so as to obtain an inclination of about 40°, and even more if
possible, and then I introduce through an opening in one of the ends of the
cases or drawers a sand heated to about 300° centigrade in order to effect
the fusion of the pulverized substances. When the fusion is completed, the
sand in the apparatus is emptied out by giving it an opposite inclination to
the preceding one, and by opening the extremity of the drawer which was
kept shut to keep the sand in, the cold air is introduced into the drawers
through a ventilator. The cooling being effected I loosen my presses and
open the apparatus to take out the joined wood and my work is done. Draw-
ing 1, Figure 3, is a front elevation of the apparatus for heating the sand.

page_text: Drawing 2, Figure 1 is a section of the furnace, and Figure 2, a plan of
the same; Figure 3, is a front elevation of the bell or sphere containing the
sand to be heated; Figure 4 and 5 shew a plan and section of the part C for
closing or stopping up the bell A; Figures 6, 7, and 8 shew a plan, front
view, and section of the spout or funnel D. I heat the sand employed to
effect the fusion of the adhesive substances herein-before mentioned by intro-
ducing it into the sphere A, Figure 3; that sphere is adapted to the top of the
furnace B, Figure 1, and the sand which is contained in the sphere is agitated
by turning the handle E adapted to it.
The furnace on which the sphere is adapted is set on wheels rolling on
rails, to allow of its being brought in front of the apparatus when it is
necessary to introduce the heated sand in it.
When arrived at that place, the
sphere is raised by means of a crank as far up as required, where supports
are fixed in order to receive it. In place of the stopper of the sphere C,
Figures 4 and 5, a sort of spout D, Figures 6, 7, and 8, is substituted, which
distributes the sand as it enters in equal quantities in each of the drawers of
the apparatus.
Drawing III., Figure 1 is a section through A, B, of the table for sprinkling
the sheets of wood to be united; Figure 2 is a horizontal projection of the
said table overturned; Figure 3, a vertical projection of the table; Figure 4
is a section of the sprinkling box G; and Figure 5 is a horizontal projection
of the same.
The table E, Figure 1, on which I spread the sheets of wood to cover them
with powder, is of the same height as the under plate of the apparatus. The
frame or flap F, Figure 3, is isolated from the table, exceeds it in height, and
serves to support the sprinkling box G, and make it slide so as to deposit the
powder contained in it.
When the sheets of wood are prepared, the frames or flaps are lowered, so
as to cause the whole of the sheets to slide together on to the lower plate of
the apparatus.
By means of a piece II, Figure 5, the extremities of which strike against
the frame of the table, when the box slides it opens of itself at the upper
part, and the powder escapes through the narrow opening made and spreads
over the sheets of wood. The superfluous powder passes under the table into
a chest with a funnel, Figure 6, without bottom, and falls into a box, Figure 7,
prepared to receive it.
The mode of operating is as follows:-I trim, join, and glue together
lengthways sheets of wood to obtain the desired width, and I take a sufficient

page_text: number to form the thickness I intend the board to have; I place them
during four or five hours in the stove heated to 60° centigrade. After with-
drawing them, I lay one of them on the table E, and I sprinkle it with
powdered gum lac or any other adhesive substance suitable for that purpose,
either alone or combined. The sheet being so prepared, I lay a second sheet
on the said table, which I sprinkle over in a similar manner to the first, and
so on until the last sheet. The operation is continued in the same manner
whatever be the number of sheets I intend to join together. It is easy to
understand that the sheet forming the outside sheets of the board do not
require any powdering.
The powdering operation, as herein-before described, being concluded, I
draw the table on which the sheets of wood have been prepared close to the
apparatus for pressing them and effecting the fusion of the pulverized
substances.
To ensure a perfect evenness of this prepared wood, which I call anhygro-
metric wood, one of the necessary conditions is, that the heat should be
equally distributed over the surface of the apparatus herein-before described,
by which the pressing and fusing of the pulverized substances is effected.
The wood so prepared is perfectly protected from warping and shrinking,
and in that state is eminently useful and advantageous for the panels and
bodies of all kinds of carriages, the hangings and floorings of apartments,
painting and drawing boards, and rollers for printing on paper and stuffs, for
certain articles of furniture, and for numerous other similar applications.
And having now described the nature of my said Invention, and the
manner of carrying the same into effect, I wish it to be understood that I do
not confine myself to the precise details or modi operandi herein laid down,
provided the main features be preserved, nor do I claim the different parts of
the apparatus taken separately or singly; but what I do claim as my Invention,
and intend to be protected by the said Letters Patent, is,―
Firstly, the application of an adhesive substance in a state of powder
between the surfaces of sheets or pieces of wood to be united, and the
softening and fusing the same, by the transmission of heat through the
thickness of the wood for protecting the same from. warping or shrinking, as
herein-before described, and referred to in the different Figures of the
Drawings.
Secondly, the application of the apparatus for effecting the sprinkling and
fusion of the adhesive matter, as herein-before described, and referred to in
Figures 1 and 2, Drawing 1, and Figures 4 and 5 of Drawing 3.

page_text: Thirdly, the apparatus for filling the boxes or drawers with heated sand, as
herein described, and referred to in Figures 6, 7, and 8, of Drawing 2.
In witness whereof, I, the said Claude François Tachet, have hereunto
set my hand and seal, this Thirteenth day of May, One thousand
eight hundred and fifty-two.
CLAUDE FRANÇOIS (L.S.) TACHET.
CLAUDE FRANÇOIS (L.S.) TACHET.
This is the Specification marked A, and referred to in the affidavit of William
Armand Gilbee, sworn before me, the 15th day of May 1852.
R. CROSBY.
William Armand Gilbee, of 4, South Street, Finsbury, in the County of
Middlesex, Patent Agent, maketh oath and saith that he is acquainted with
the manner and character of the handwriting of Thomas Pickford, Iler
Britannic Majesty's Acting Consul, at Paris, in the Republic of France; and
this deponent further saith, that the signature. of "Thomas Pickford," set
and subscribed or written in the margin of the Specification hereunto annexed,
marked "A," and dated the Thirteenth day of May instant, and purporting
to be executed by Claude François Tachet, of Paris, in France, Mathematical
Instrument Maker, whereby it is stated, that the Specification was acknow-
ledged by him, the said Claude François Tachet, before the said Thomas
Pickford, on the said Thirteenth day of May, at Paris aforesaid, is of the
proper handwriting of the said Thomas Pickford.

page_text: AND BE IT REMEMBERED, that on the oath of William Armand
Gilbee, the Specification aforesaid was enrolled word for word, as above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Enrolled the Fifteenth day of May, in the year of our Lord One