Improvements in and connected with Wood Embossing.
Year: 1892

page_text: Date of Application, 27th May, 1892-Accepted, 2nd July, 1892
COMPLETE SPECIFICATION.
Improvements in and connected with Wood Embossing.
I, PAUL GASSEN of 19 Pantaleonsgasse Cologne in the Kingdom of Prussia and
German Empire, 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 :-
A great disadvantage attending the embossing of wood in intaglio and in bas-
relief, as at present practised, is that the embossed articles subsequently become
warped and distorted. This serious defect is more particularly noticeable in the
larger articles, and generally is accompanied with a convexity of the back in the
case of intaglio or sunk and hollowed designs, and a concavity in the case of relief
embossing. This is quite independent of the twisting and warping which may be
produced by atmospheric moisture. Another defect is that, should the article,
subsequent to the embossing, become wet or moist, the embossment will be wholly
or partly effaced.
I
The object of this invention is to obviate these defects and for this purpose
endeavour to place both sides of the wood in the same conditions of compression
and extension during the process of embossing, and in order to prevent the action
of moisture, I saturate the compressed wood with a suitable water resisting material
or compound.
For the purpose of ensuring approximately the same condition of compression
and extension on the embossed and reverse sides of the wood, I may emboss it on
both sides.
A similar result may be obtained by the use of a backing plate fitted with conical
pegs upon which the wood is placed during the process of embossing. These pegs
enter the back of the wood and press it laterally. The largest displacement of the
wood takes place on the back surface owing to the conical shape of the teeth. If,
instead of conical teeth, teeth having a cubical form be employed, the opposite
effect is obtained, since in this case, the interior of the wood is compressed and the
back of the wood is made more or less convex. Hence, to cure or prevent the
possibility of a concave face, conical pegs may be employed and for the reverse,
cubical pegs.
Except when the conical pegs are used, the impressions made by embossing the
back, or by the cubical teeth, may be removed by planing or otherwise either
wholly or in part as may be desired. As the compression or lateral displacement
produced by the conical pegs is principally on the back surface, it will be obvious
that if this surface be removed by planing or otherwise, the condition will be
removed also. This is not the case when the back of the wood is similarly embossed
with the front nor when the cubical pegs are used.
For the purpose of preventing the action of moisture and water on the embossed
wood, the dry wood is compressed as heavily as may be convenient, so as to con-
siderably reduce its bulk, in which condition it is treated with an anti-hygroscopic
or water resisting material or compound. Suitable materials for this treatment are
melted resinous substances, dissolved resins, melted paraffin, or a chromated glue
solution. The compressed wood is submerged in the material for a sufficient time
to enable it to penetrate to a sufficient depth to be thoroughly effective. The
duration of the treatment will vary with different woods, with the same wood at
different ages, and upon the degree of pressure, and will be found in each case by a
simple trial. The wood is then removed from the bath, cooled or dried, and is
embossed as already hereinbefore described.
If chromated glue be used, in solution, the wood should after treatment be
insolated or fully exposed to actinic light. The wood treated as set forth will not

page_text: lose the embossed effects thereafter produced upon it, in consequence of any
exposure to damp or moisture.
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 :-
1. The hereinbefore described method of embossing wood, consisting in embossing
the same pattern upon the back and front and thus producing the same conditions
of compression on both surfaces, substantially as and for the purpose hereinbefore
described.
2. The hereinbefore described method of treating embossed wood, consisting in
impressing the back of the wood with conical or cubical teeth or pegs and thus
producing similar conditions of compression in both surfaces, substantially as and
for the purpose hereinbefore described.
3. In the production of embossed wood articles, compressing the dry wood,
treating the compressed wood with an anti-hygroscopic or water repellant material
or compound, and thereafter embossing it; substantially as and for the purpose
hereinbefore described.
WILLIAM E. HEYS,
Agent for the Applicant.