IMPROVEMENTS IN SCULPTURE COPYING APPARATUS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Gerhard Mathis at the Office
of the Commissioners of Patents, with his Petition, on the 11th
March 1878.
I, GERHARD MATHIS, of Villingen, in the Grand Duchy of Baden,
but at present of No. 20, Southampton Buildings, Chancery Lane, in
the County of Middlesex, do hereby declare the nature of tho said
Invention for "IMPROVEMENTS IN SCULPTURE COPYING APPARATUS," to be as
follows:-
This Invention relates to apparatus whereby a copy is made from a
sculptured model by the action of a drill or revolving cutter guided so as
to penetrate to the proper depths at different parts of the block of material
in which the copy is executed. For this purpose the model and the
block to be sculptured are fixed each upon a sliding table, and these two
tables are connected so that when either is moved the other is moved
3 equally with it. Above the two tables are two levers mounted in fulcra
formed like gimbals, so that either lever can oscillate both vertically and
horizontally. The end of each of the two levers which is presented to
that of the other is formed with a head which is a segment of a sphero
struck from the centre of motion of the lever as a centre, The two

page_text: spherical segments thus presented to and touching each other are
provided with teeth or projections and hollows which gear them together
in such a manner that when the one lever is made to oscillate either
vertically or horizontally the other lever is made to oscillate to the same
extent and in the same direction. At the end of one of the levers is |
fixed a dumb drill or tracer the point of which can be moved over the
surface of the sculptured model. At the end of the other lever is
mounted a drill or revolving cutter driven by a strap from a pulley
mounted at the centre of motion of the lever, the latter pulley being
itself driven by a strap from any convenient rotating pulley external to ]
the apparatus. The drill or rotating cutter being pressed against the
block to be sculptured removes a depth of the material determined in
quantity and position by the extent to which the dumb drill or tracer of
the other lever can be depressed, till it reaches the surface of the model.
When by this action of the drill or cutter one line or groove of the
material has been removed from the block to be sculptured, the tables
holding the model and block are moved so as to bring another line or
groove within range of the cutter, and this being cut the process is
repeated till the whole surface of the block is sculptured to the
configuration of the model.
Sometimes it is desired that the copy should be made to the opposite
hand of the model. To provide for this the two tables instead of being
rigidly connected so as to move together in the same direction. are
connected by racks and gearing so as to move equally in opposite
directions.
The two tables described above may be mounted on longitudinal axes
so that they can be canted to any required angle in order to effect
under cutting, or to permit the drill and tracer to reach points at cither
side of the model and block.
When the tables are geared to slide in opposite directions in order to
effect a copy to the opposite hand of the original - their canting is
also effected in opposite directions by means of gearing connecting their
respective axes.