IMPROVE- MENTS IN FILE-CUTTING MACHINES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by James Dodge at the Office of the
Commissioners of Patents, with his Petition, on the 26th April 1865.
I, JAMES DODGE, of Manchester, in the County of Lancaster, Mechanical
Engineer, do bereby declare the nature of the said Invention for "IMPROVE-
MENTS IN FILE-CUTTING MACHINES," to be as follows:-
My Invention consists, firstly, in the use of apparatus whereby the motion
of the machine is arrested when a faulty cut has taken place. For this
purpose I cause an instrument to traverse each cut as it is effected, and thus
to feel as it were for any irregularity. Should such an imperfection exist
the resistance thereof causes a shifting of parts which disengages the machine
from the motive power. In an arrangement I at present propose the instru-
ment above mentioned is mounted in a frame to which a reciprocating motion
is imparted by an excentric on the main shaft, and acting through the inter-
vention of levers. The main shaft is driven through the medium of a clutch
box, the two parts of which are kept in gear against the elastic force of a
spring. Should any impediment occur to the passage of the reciprocating
instrument along a cut of the file then the said instrument by being turned
from its course liberates the above-mentioned spring and the two parts of
the clutch box pass out of gear, and thus the motion of the machine is
arrested.
In place of the above-mentioned operation of the instrument I cause it in
a similar manner to feel the edge of the cutter so as to detect its condition and

page_text: to arrest the motion of the machine if necessary, and this method may be adopted
when rotatory cutters are employed by causing the said cutters to run in
contact with the said instrument.
Another part of my Invention consists in a method of arranging the
standards or guides for the cutter, the object being in the first place to cause
the said cutter to act with a vertical force so as to avoid a lateral strain upon
the guides, and, secondly, to admit of a variation of the angle (in reference
to the blank) at which the cut is effected. The first of these objects I
accomplish by forming the cutting edge at right angles to the direction it
moves in, and by inclining the standards or guides to enable the rectangular
cutter to operate obliquely. The second object is effected by mounting the
standards or guides upon pivots, thus rendering them capable of being swivelled
to any desired angle.
Another part of my Invention relates to a method of modifying the force
of the cutter according to the comparatively narrow or broad surface of the
blank which it has to act upon. For this purpose I employ a template or
shaper travelling with the blank, and acting upon a rod or lever which relaxes
or increases the tension of a spring used for forcing the cutter forward. Or, if
the elastic force of steam or air be employed for actuating the cutter, the said
template or shaper acts through the medium of the rod or lever for opening
or contracting the steam or air passage.
Another part of my Invention has reference to a method of preventing a
rebound of the cutting tool, by which the teeth of the file become injured.
For this purpose I give a certain amount of elasticity to the bed which
carries the blank, or I place an elastic substance between the chisel and its
holder.