A Process for the Production of Ornaments or Figures Imitating Medieval Wood-carving such as "Tarsia"-work or the like.
Year: 1893

page_text: COMPLETE. SPECIFICATION.
A Process for the Production of Ornaments or Figures Imitating
Medieval Wood-carving such as "Tarsia"-work or the like.
A communication from ERNST AUGUST WEIDEMANN, of Liebenburg, in the Harz
District, German Empire, Manufacturer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 :-
Hitherto the production of ornaments has not been feasible except in planks or
blocks of wood cut across the fibres, to increase the resistance of which it was
necessary to superpose and glue together a number of veneers with their fibre respec-
tively at right angles. Wood cut along the grain is deficient in the quality which
would allow it to accommodate itself, or be moulded by, shaping-rollers or stamping-
dies with perfect nicety. The shaping of such wood therefore cannot be proceeded
with without a certain preparation, inasmuch as where the ornament or design
presents very deep or sharp lines or edges, the splitting of the wood is almost
unavoidable, for the reason that the heated dies render the wood too brittle, and
at the same time effect the impression of the figures too abruptly.
The present process enables all the drawbacks hitherto experienced in the treat-
ment of such wood for ornament-producing purposes to be avoided and thorough
reproduction or copies of figures carved by hand to be obtained.
The pieces of wood cut along the grain, and in which the designs or figures are
to be imprinted, are first cut to the required size (several of them being combined,
or not, as may be required) and boiled in a weak solution of glue for about one
hour, and then dried. In the case of thin planks of wood cut along the grain the
boiling in the solution of glue is not absolutely necessary, it being sufficient to
cover them with the boiling solution.
The surface which is to receive the ornament is then smoothed or polished, and
in this condition it is ready for ornamenting, except that just before the shaping
or pressing of the ornaments is proceeded with, the following preparatory operation
should be performed.
A short time before pressing or stamping out the required ornaments, the planks
or blocks are subjected for 20 seconds to the action of a steam-jet, on the side
which is to receive the ornamentation, by which means the upper fibres on
that side are rendered more supple and better capable of assuming the required
shapes.
The longitudinal fibres, however, do not by mere pressure allow themselves to be
moulded so as to fit exactly any sharp-edged recesses which the heated die may
present so that unless special precautions are taken, the impression which the form
will leave, must necessarily be an imperfect one. To prevent this, the block or
piece of wood cut along the grain is not placed with its back directly touching the
shaping-table but an intermediate plate or support of wood cut across the grain is
interposed between it and the said table. In the case of very thin planks of wood
cut along the grain (so thin as to be comparable to veneers) the support of wood
cut across the grain is preferably glued on or otherwise secured beforehand to the
back of the plate or piece to be ornamented.
As a substitute for wood cut across the grain, soft metal, cork, indiarubber, or
other flexible material, may be employed as a support.
After these preparations the stamping die operated by means of a suitable press
is allowed to act upon the plank or block placed upon the shaping-table or support,
and it will be understood that owing to the nature of the support the impression of

page_text: the desired figure or ornament in the longitudinal fibres of the wood will take
place gradually.
The breaking of the blocks cut along the grain, during the stamping or pressing
process, is effectually avoided, and the shaping-forms may be impressed into the
material to any desirable depth, so that if suitable wood be chosen and sufficiently
good taste displayed in the selection of the ornaments, some of the finest
specimens of mediaeval decorative art, such as the beautiful "tarsia" work may be
reproduced.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is,-
A process for the production of ornaments or figures mainly imitating mediæval
wood-carving such as "tarsia"-work in longitudinally cut wood characterized by
the following operations, the impregnation of the planks or blocks of wood cut
along the grain with a boiling solution of glue after which they are allowed to dry
the surface to be ornamented being then properly smoothed or polished and before
the actual stamping-out or pressing of the ornaments is started subjected to the
action of a jet of steam for the purpose of rendering their fibres more supple the
planks or blocks being placed during the stamping or pressing process upon an
intermediate plate or support preferably of wood cut across the grain and which
may be glued or otherwise secured to the back of the said plate or block soft
metal cork indiarubber or similar material being also suitable as a substitute for
wood cut across the grain.
Dated this 28th day of February 1893.
W. P. THOMPSON & BOULT,
'Agents for the Applicant.