IMPROVEMENTS IN MACHINERY FOR SHARPENING AND SETTING SAWS
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark, at
the Office of the Commissioners of Patents, with his Petition, on
the 4th September 1872.- A communication from abroad by
Laurent Martinier, of Lyons, France.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MACHINERY FOR SHARPENING AND
SETTING SAWS," to be as follows:-
This Invention relates to improvements in the construction, of
machinery for sharpening and setting saws, and more particularly band
saws, whereby the teeth of a saw may be sharpened without varying
their distance apart, or they may be "set" or inclined alternately to one
side or the other to any required angle with a degree of precision un.."
attainable by the most practised hand.
The operations of setting and sharpening may be effected by two
distinct machines, which however have parts that are similar to or common
to both, or one machine may be made to perform both operations by
simply changing the tools.

page_text: In the accompanying Drawings Figure 1 shows a section of a machine
for "setting" the teeth taken in the plane of the saw to be set; Figure 2
shows a plan of the same machine; and Figure 3, a cross section of the
same through the setting tools.
Figures 4 and 5 show sections of a simplified machine of smaller size
for setting the teeth taken transversely to and on a line with the saw
respectively.
The machine shown in the two last Figures is adapted for saws which
are not endless, as the tool can work close up to the holding device to
which the ends of saws having alternate motion are usually attached.
Figure 6 shows a vertical section of a machine for setting the teeth of
circular saws taken on a line passing through the centre of the saw and
the setting tools; Figure 7 shows a plan of the same machine; and
Figure 8, a vertical section taken on the plane of the saw.
Figure 9 shows a vertical section through the setting tools of a
machine still further simplified, for medium and small sizes, Figure 10
being a vertical section taken on a line parallel with the saw, and
Figure 11 a plan of the same machine.
The same letters of reference indicate like parts in all the Figures.
A, support capable of being adjusted vertically in a guide B on the
frame E; C, screw for adjusting support A working in a socket b and
operated by a hand wheel c; the back of the saw blade rests on the top
of support A at a point opposite the teeth on which the tools are to act;
the saw blade is supported in the position shown by the sliding or
pivoting jaws D, D', mounted in the frame E, and capable of being
moved to and from one another to grip the saw blade between them and
support it in the required position, or to permit of its being advanced as
the work progresses; d, springs by which the jaws are closed together to
clamp the saw. The blade is shifted to present the teeth successively
to the sharpening or setting tools, by causing it to slide on the support A
the exact distance of one tooth at each time whatever may be the
size of the teeth; this is effected by making the saw teeth themselves
the guage which determines the distance the saw is to advance, the saw
teeth serving as a rack for a pawl or blade H which engages with the saw
teeth, as shown, and to which to-and-fro motion is imparted; the extent
of the motion may be regulated approximately to the size of the teeth

page_text: but the saw is shifted the exact distance of one tooth at each forward
movement of the pawl; h, set screw for lengthening or shortening the
pawl H in order to bring the tooth to the exact position in which it is
required to be acted on by the tools; I, hand wheel, or it may be a
pulley to which power is applied to drive the machine and impart two
distinct movements, one the shifting movement of the saw in the
direction of its length just described, and the other an alternate move-
ment sideways to force it against the setting tools when these are fixed,
or the movement may be imparted to the tools, the saw being stationary,
and any suitable means of transmitting these movements may be
employed. In all the machines shown the alternate transverse move-
ment of the jaws D, D¹, is produced by the oscillation of levers M, M,
pivoted at m, the extent of whose movement is regulated by levers N, N,
whose oscillation is limited by stops n, n; 0, 0, setting tools fixed when
the saw is oscillated and forced against them, and movable as before
mentioned when the saw is stationary; their action is regulated by the
set screws 0, 0.
The grinding or sharpening of the teeth is effected by suitable files or
grinding wheels to which rectilinear or rotary motion is imparted, pro-
vision being made for raising and lowering the tool and limiting its
action to regulate the depth of the tool.