IM- PROVEMENTS IN FILE-CUTTING MACHINES
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by Henry Garside at the Office of
the Commissioners of Patents, with his Petition, on the 11th
July 1868.
I, HENRY GARSIDE, of Manchester, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN FILE-CUTTING MACHINES," to be as follows:-
The machine consists of a bed either horizontal or somewhat inclined
with framing which may be at right angles with or inclined to the bed.
The bed carries a massive slide, on the upper side of which is mounted
an anvil, the sections of which are semicylindrical or nearly so, and on
the flat face of which anvil is placed the file blank to be cut, a strip of
softer metal being however interposed to deaden the blow. The cutting
tool is held at the lower extremity of a ram which slides freely in guides
attached to or forming part of the framing, and to which ram a recipro-
cating motion is given by the combined action of a cam on the driving
shaft which lifts the ram and a spring which reacts and gives the
necessary blow. The file while being cut is held down with sufficient
firmness by means of a presser piece which may be attached either to a
sliding bar with a right line motion, or to an arm with a circular motion,
a sufficient and adjustable pressure being given in either case by a lever

page_text: with a weight or spring. To aid the action of the presser in main-
taining a due relation between the face of the file while being cut and
the cutting instrument I sometimes use a tilt lever attached to the end
of the anvil, which tilt lever may be held against a shaped tilting plate
fixed to the bed. By this means some files (especially while the points
are being eut) are more rigidly retained in the proper position to
receive an even cut. The feed motion for spacing the teeth consists of
a guide screw working in bearings at the ends of the bed actuated by a
ratchet wheel and pawl and engaging with a clasp nut attached to the
slide. A feed cam or excentric on the driving shaft imparts the necessary
motion to the pawl by means of a lever or rock shaft placed alongside
the bed. A return spring is employed to compensate for wear and to
keep the working surfaces in contact,
To obtain the varying force of blow necessary to meet the different
widths of files or the varying width of the same file I employ a shaper
or incline fixed to the main slide. This incline acts upon one end of a
lever, the other end being attached to a tension rod which communicates
the necessary downward pressure to the ram spring through a forked
lever. A screw is formed at one end of the tension rod which works in
a nut attached to the forked lever, and a hand wheel is fixed on the
tension rod, by turning which the operator is enabled to regulate the
force of the blows with great nicety.
It is in many cases desirable that the teeth should be not only less
deep about the point of the file, but also closer together. This is
accomplished by the employment of a curved or inclined stop piece also
attached to the main slide which is so arranged as to prevent the move.
ment of the cam or excentric from taking full effect on the feed motion
for the necessary distance.
In order to stop the machine by self-acting mechanism when the
cutting of each course is completed, I use the following arrangement:-
To the side of the slide is attached an adjustable stop, which by coming
in contact with the end of a lever releases the strap fork from a catch
and thus allows a spring to act on the belt fork and pass the driving belt
on to the loose pulley.