Improvements in Apparatus for Sharpening Certain Files.
Year: 1892

page_text: Date of Application, 29th Apr., 1892
Complete Specification Left, 30th Jan., 1893-Accepted, 4th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Sharpening Certain Files.
I, JOHN LAWRENCE STEWART, of Dumb Mill, Frizinghall, near Bradford in
the County of York, Manufacturer, do hereby declare the nature of this inven-
tion to be as follows:-
This invention relates to improvements in apparatus for sharpening that class of
files for cutting, abrading and smoothing metal and other substances, in which the
teeth or cutting edges are formed on the edges of steel plates mounted side by side
in a frame or holder and its object is to provide a simple and accurate method of
uniformly sharpening said teeth or cutting edges at the proper angle.
For this purpose I remove the plates to be sharpened from the said holder and
place them in a suitable rack the divisions of which are such a distance apart and
at such an angle that they accurately hold the plates placed between them parallel
to each other and at an uniform and suitable angle for sharpening. Said plates are
clamped in this position between adjustable side guides engaging the ends of the
plates. These side guides are preferably so formed and arranged that they engage
the notches in the ends of said plates and tend to draw the upper sides of such
notches tightly against the top of said guides for the purpose of keeping the edges
of the plates to be ground uniformly in position.
Dated this 28th day of April 1892.
DRACUP & NOWELL,
Bradford, Agents.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Sharpening Certain Files.
1, JOHN LAWRENCE STEWART, of Dumb Mill, Frizinghall, near Bradford,
in the County of York, Manufacturer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :―
This invention relates to improvements in apparatus for sharpening that class
of files for cutting, abrading and smoothing metal and other substances, in which
the teeth or cutting edges are forined on the edges of steel plates mounted side
by side in a frame or holder and its object is to provide a simple and accurate
method of uniformly sharpening said teeth or cutting edges at the proper angle.
For this purpose I remove the plates to be sharpened from the said holder
and place them in a suitable rack the divisions of which are such a distance
apart and at such an angle that they accurately hold the plates placed between
them parallel to each other and at an uniform and suitable angle for sharpening.
Said plates are clamped in this position between adjustable side guides engaging
the ends of the plates. These side guides are preferably so formed and arranged
that they engage the notches in the ends of said plates and tend to draw the
upper sides of such notches tightly against the top of said guides for the purpose
of keeping the edges of the plates to be ground uniformly in position.
Reference is to be had to the accompanying sheet of drawings forming a part of
this Specification in which similar letters of reference indicate corresponding parts
in each of the figures.
Figure 1, represents a side view of my improved sharpening apparatus with one
division of the rack filled with file plates in position for sharpening. The full
length of the apparatus is not shown in order to represent it upon a larger scale, it
may however be made of any convenient length.

page_text: Figure 2, represents a similar view with one of the side guides removed.
Figure 3, a plan view.
Figure 4, a cross section on the broken line a, b Figure 1 and Figure 5, a similar
section on the broken line w, z.
Figure 6, is a view of one of the file plates.
The side guides A and A' are adjustably connected together at suitable intervals
by the stud bolts B rigidly secured in the lugs C on A and closely fitting holes in
the lugs D of A' through which they pass and their extremities are provided with
clamping nuts E bearing upon the outer side face of A'.
The rack F has divisional pieces G are equal distance apart and inclined at a
suitable angle and the spaces H between the divisional pieces G are of such a size
that they exactly hold a certain number of the plates J. The whole of the spaces H
are filled with plates and the rack with the plates in position is placed between the
side guides A and A¹ and rests upon the lugs C and D. The side guides are then
adjusted towards each other and the lips K, K of the guides enter the end
notches N, N of the plates and are tightly clamped in this position.
The under-
side of the lips K, K are inclined so as to cause the top sides M of the notches to
bear upon the top face of the lips and thus bring the plates all in line without
relying in any way upon the bottom of the rack.
When the plates are all clamped in this position their top edges are ground in
any convenient manner parallel to the top face of the lips K, K, and are thus when
removed from the apparatus practically uniform and interchangeable.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :
1. The apparatus herein described for holding file plates in position for
sharpening.
2. The combination with the rack F of adjustable side guides A and A', sub-
stantially as herein shown and described and for the purpose specified.
Dated this 27th day of January 1893.
DRACUT & NOWELL,
Bradford, Agents.