IMPROVEMENTS IN CUTTING FILES, AND IN MACHINERY TO BE EMPLOYED FOR THAT PURPOSE
Year: 1862

page_text: LETTERS PATENT to Jorgen Balthazar Dalhöff, of Copenhagen, in the
Kingdom of Denmark, Goldsmith, for the Invention of "IMPROVEMENTS
Saled the 12th June 1863, and dated the 22nd December 1862.
PROVISIONAL SPECIFICATION left by the said Jorgen Balthazar Dalhöff
at the Office of the Commissioners of Patents, with his Petition, on the
22nd December 1862.
I, JORGEN BALTHAZAR DALHÖFF, of Copenhagen, in the Kingdom of Den-
mark, Goldsmith, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN CUTTING FILES, AND IN MACHINERY TO BE EMPLOYED FOR THAT
PURPOSE," to be as follows:-
My improvements consist, firstly, in keeping the chisel holder firmly pressed
against the surface of the file whilst the blow is struck, so that the file is kept
quite steady, and as the chisel holder is apt to turn with the movement of the
file, the chisel also is moveable, and thus always maintains its parallelism with
the surface of the file. The chisel is short and convex at the back, fitting a
concave cushion or back plate which is moveable, the front of the chisel is
flat, and a block piece presses against this flat side, thus wedging the chisel
between the back cushion and the front block, this block is adjusted by a

page_text: regulating screw with a ball at its end working in a socket in the block piece,
the motion of the chisel holder is thus quite regular, and the depth and size
of the teeth required can also be regulated. The action of the hammer is a
double one, and its weight may be increased to any extent, thus preventing
vibration, and ensuring a dead firm cutting blow. A regulating bar at the
side of the machine governs the force of the blow, and adapts it to either a
pointed or blunt file. The anvil is circular, similar to a roller, affording a
firm foundation when the blow is struck whatever the size of the file, and
thus avoids the necessity of fixing the file, and this anvil being separate from
the machine no vibration takes place.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jörgen Balthazar Dalhoff in the Great Seal Patent Office on
the 19th June 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JÖRGEN
BALTHAZAR DALHOFF, of Copenhagen, in the Kingdom of Denmark, Gold-
smith, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of December, in the year of our
Lord One thousand eight hundred and sixty-two, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Jörgen Balthazar Dalhoff, Her special licence that I, the said
Jörgen Balthazar Dalhoff, my executors, administrators, and assigns, or such
others as I, the said Jörgen Balthazar Dalhoff, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and law-
fully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN CUTTING FILES, AND IN MACHINERY TO BE EMPLOYED
FOR THAT PURPOSE," upon the condition (amongst others) that I, the said
Jörgen Balthazar Dalhoff, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Görgen Balthazar Dalhoff, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being bad to the accompanying Drawings, that
is to say:
No. 1, side view of the engine; No. 2, end view of the same; No. 3, sec-
tional view, shewing the mechanism for pressing the chisel holder against the
file; No. 4, a sectional birds-eye view of the middle where the screw and nut
is shewn. The same objects represented in the different Drawings are indi-
cated with the same letters.
a, an elevation of the frame; b, two round bars, serving as guide for the
reciprocating parts holding the file; c, a solid disc of metal composition of
zinc, and serving as anvil on which the files are cut; c¹, a band of steel fixed
at a', which turns the anvil while the file advances, the anvil is provided with
corresponding grooves for files, being much bellied in the middle, causing that
part of the file to be cut always to be the same level and horizontal; c¹¹, two
irons bars fixed by screws to the anvil for guiding the file. When cutting
very thin files the anvil is to be fastened by screws so as not to turn, or sub-
stituted by a common anvil with a groove, in which an iron bar on which
the file is placed can slide; d, a falling hammer, which below is guided by
rollers, and above by means of a tap. It is in the middle provided with two
heavy plates dat each side, applied for producing an after stroke; the said
plates are connected by bolts, the uppermost of which is round, and surrounded
with india-rubber, while the lowermost is wedge formed. When the hammer
has fallen, the wedge receives directly an after stroke, the consequence of
which is that the stroke is deadened, and the hammer never hops. The
hammer may below be provided with a firm chisel holder d², or merely with a
smooth surface for a separate chisel holder; e, a chisel holder in the frame
represented is applied a piece of metal e' with a round tap e
behind, being
in front provided with a circular groove in which the chisel slides. The
chisele forms part of a circle. On receiving the stroke it turns on its centre
in the ball-formed head of the screw e', a small spring forces it up again. "The
chisel holder is by means of the mechanism es, Ns, pressed strongly against
the file a little before the stroke takes place, whereby the file is being held
fast, while e turns round its pivote, so that it lies on the surface of the file,
the consequence of this arrangement being that the chisel directly strikes the
file with its whole length of the cut, even when the surface of the file forms
a slope. The chisel cuts into the file with certainty, and the depth of the cut

page_text: can therefore be determined. The metal piece e is with reference to the
second cut provided with india-rubber below in order not to injure the teeth
made; f, a cylinder in which is applied a spiral spring in order to increase
the force of the stroke; 9, an iron bar, serving to stop the engine or regu
lating the stroke when wanting to be stronger on the middle than the ends of
the file; it is by means of a thin bar g¹ connected with a lever g² on the top
of the engine, when pressed down the spiral spring in fis .also pressed down
strengthening thereby the stroke; g³ is a bar of iron wedge-formed 'below,
which when pressed down keeps the steel plate f¹ back, as it otherwise would
support the hammer at its top point; h, a piece of metal sliding on the bars,
and guiding the end of the screw, it is provided with a roller h¹,. and a. wedge-
formed incline 2. The bar g is to have such a slope or curve as required by
the slope of the file. When the engine is to be started, the bar is pressed
below the roller h, so the said roller advances with the screw above the upper-
most edge of the bar, the bar will be pressed down at the point where it was
when being at its highest level, and the strength of the stroke thus increased
at this place. When the metal piece h has advanced at the place where the
cutting ceases, the wedge h² strikes a piece h³ fixed to the bar, whereby it
is pressed outside the roller, it jumps then up, and the engine stops; i'a
piece of metal sliding on the bars b, it is provided with a tong ¹, which
receives the file when advancing after the cutting; the said tongs can sink
and rise according to the up-and-down 'motion of the point of the file, 'iú
order that the place to be cut may be placed horizontal, is however by means
of the spring always' pressed somewhat downward, and the whole is by
means of the weight, and together with the file kept right back against the
screw; k, a rachet shaped nut with two palls on a ring, which on being moved
to and fro turns the nut, and causes the screw to advance; a steel spring &¹ is
fixed on the ring, terminating at the one end with a spring, the other end
is connected to a lever ³ below, extending hence to the eccentric on the
axlè l, producing thereby the motion; 1, the main axle, with pulleys for bitts,
fly-wheel, and 8 eccentrics, one for lifting the hammer, one for turning the
nut, and one with a roller for pressing down the chisel holder.
Having thus described the nature of my Invention, I declare that what 'I
claim is as follows:-
1st, the chisel holder e, which by its pressure holds fast as well the file as
the chisel.
2nd, the curved motion of the chisel.

page_text: 410, the anvil c being round.
5th, the tongs i guiding the file without preventing the point of the same
to move up and down.
6th, the bar g, which when given a certain shape, may cause the file to be
cut more hard at the places desired.
In witness whereof, I, the said Jörgen Balthazar Dalhoff, have here-
unto set my hand and seal, this Nineteent day of June, in the year
of our Lord One thousand eight hundred and sixty-three.
JÖRGEN BALTHAZAR DALHÖFF. (L.S.)