IMPROVEMENTS IN SHARPENING AND SETTING SAWS, AND IN THE MACHINERY OR APPARATUS EMPLOYED THEREIN
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the
Office of the Commissioners of Patents, with his Petition, on the
21st December 1868.-A communication from abroad by Charles
Aimé Perrey, of Paris, in the Empire of France.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SHARPENING AND SETTING SAWS, AND IN
THE MACHINERY OR APPARATUS EMPLOYED THEREIN," a communication to me
from abroad by Charles Aimé Perrey, of Paris, in the Empire of France,
to be as follows:-
This Invention relates to a simple contrivance for effecting the
sharpening and setting of the teeth of endless or ribbon saws without
necessitating the dismounting of the saw or requiring skilled labor in
conducting the operation.
According to this Invention it is proposed to adapt temporarily by
means of bolts or other convenient fastenings a small frame to a
convenient part of the saw frame, such small frame containing the.
sharpening and finishing or polishing appliance and means for working:
the same. The saw to be operated is steadied between guides, and the
teeth are then successively sharpened by bringing to bear upon them

page_text: a file made in the form of an endless screw or helix, which is formed
on a steel cylinder or boss mounted on the lower end of a revolving
On
spindle worked by a winch handle and pair of bevel wheels.
rotating the helicoidal file whilst in contact with the saw tooth its
cutting edge will be sharpened whilst at the same time the tooth last
operated upon is being finished or polished by the action of a rotatory
polisher situate beneath this file and carried by the same spindle.
The angle or "set" of the teeth is obtained in a certain and regular
manner by the aid of an adjustable instrument, which is provided with
divided scales and indicators for the purpose of enabling the instrument
to be accurately adjusted so as to give the exact "set" required to the
saw teeth. This instrument consists essentially of two moveable jaws
which meet together at one end in a centre or pivot, upon which they
move whilst their opposite ends are maintained some distance apart,
but this distance is varied as required by means of adjusting screws.
At the point of junction between the jaws a notch is formed for the
reception of each saw tooth in succession, and by partly turning the
instrument to one side or the other whilst a tooth is in the notch it will
be bent laterally or "set," as is well known, but the actual amount of
set is by this instrument ascertained as the amount of movement from
the instrument is controlled by the fact of one or other of the two
adjustable arms coming in contact with one side or other of the
saw. By employing a divided scale and indicator in connection with
each arm or jaw it is obvious that they may be adjusted to any given
angle and consequently the angle of the "set" of the saw teeth will
also be ascertained. This instrument is obviously applicable to the
"setting" of the teeth of saws of all kinds.