Improved Apparatus for Preparing Circular Saws to be Sharpened.
Year: 1890

page_text: Date of Application, 22nd May, 1890
Complete Specification Left, 21st Feb., 1891-Accepted, 21st Mar.; 1891
PROVISIONAL SPECIFICATION.
Improved Apparatus for Preparing Circular Saws to be Sharpened.
I, JESSE WOOTTON, of No. 25, Rhyl Street, Kentish Town, in the County of
Middlesex, Sawyer, do hereby declare the nature of this invention to be as
follows:-
:―
This invention relates to apparatus designed to supersede the usual practice of
applying a stone to the circular saw while in motion for the purpose of reducing
the prominence of the teeth to the same level; that is to say of reducing the height
of the teeth to an uniform range previous to removing the saw from the saw bench
to be finally sharpened by filing at the required angle.
The defective work produced by the stone grinding operation is due to the fact
that the stone cannot be held steadily is more driven off by a prominent tooth than
by a less prominent one and is cut into by the saw forming a concave surface upon
the stone giving as a result a convex surface at the summit of each tooth subjected
to the grinding action.
If as in some cases a file be applied crosswise instead of a stone the prominent
parts of the teeth are burred over rather than cut away.
By both the above mentioned arrangements a much greater proportion of the saw
is removed than is necessary to reduce all the teeth to the same length of radius,
an exact guide line for the operation of filing is not produced and consequently
the filing operation is completed without producing uniformity in length or range
of teeth.
According to my invention I provide a foundation plate preferably in the form
of an angle plate with suitable fittings for securing it firmly in position upon the
saw bench or upon the fence of the saw bench. In the vertical wall of the angle
plate form a horizontal slot having a stud capable of being fixed in any convenient
position in the slot. This stud forms a pivot from which an arm projects capable
of being clamped upon the pivot at any required angle. The arm has a continuation
piece hinged thereto at its extremity so as to fold over thereon and be brought more
or less near to contact therewith by means of a regulating screw with a spring
intervening.
This continuation piece folded over forms a holder upon which a finely cut file
may be clamped.
The apparatus being fixed in position by means of the regulating parts described
urges the file up to a definite point regulated by the regulating screw referred to
in contact with the teeth of the circular saw and the saw is pulled round
preferably backwards with the teeth travelling in the direction of the length
of the file.
By this means all the more prominent teeth are reduced to the same radial height
as the least prominent one and a definite and square outline is produced to guide
the saw sharpener in filing away in opposite directions alternately the parts of the
teeth to be cut away in order to produce an efficient cutting edge.
Dated this 21st day of May 1890.
AYRTON & THOMAS,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improved Apparatus for Preparing Circular Saws to be Sharpened.
1, JESSE WOOTTON, of 25, Rhyl Street, Kentish Town, in the County of
Middlesex, Sawyer, do hereby declare the nature of this invention, 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 apparatus designed to supersede the usual practice of
applying a stone to the circular saw while in motion for the purpose of reducing
the prominence of the teeth to the same level; that is to say, of reducing the height
of the teeth to an uniform range previous to removing the saw from the saw bench
to be finally sharpened by filing at the required angle.
The defective work produced by the stone grinding operation is due to the fact
that the stone cannot be held steadily, is more driven off by a prominent tooth than
by a less prominent one, and is cut into by the saw, forming a concave surface upon
the stone and giving as a result a convex surface at the summit of each tooth
subjected to the grinding action. If as in some cases, a file be applied cross-wise
instead of a stone, the prominent parts of the teeth are burred over, rather than
cut away
By both the abovementioned arrangements a much greater proportion of the saw
is removed than is necessary to reduce all the teeth to the same length of radius,
an exact guide line for the operation of filing is not obtained and consequently
the filing operation is completed without producing uniformity in the length or
range of the teeth.
According to my invention I provide
drawings in which Figure 1 is a side
elevation.
apparatus shown in the accompanying
elevation and Figure 2 is an end
A foundation plate A is provided with two fixed lugs B B and a movable
lug C connected with a sliding piece D which may be urged by a screw E to
cause the movable lug C to approach to or recede from the fixed lugs B B' in
order that the foundation plate A may by that means be rigidly secured upon
a saw bench in which a suitable slot or opening may be found to receive the
said lugs.
Upon the foundation plate A I mount an angle plate F capable of being securely
fastened thereon by means of screws GG passing through holes in the angle plate.
These holes are elongated to allow the angle plate F to be clamped upon the
foundation plate A in the line required to set the file square with the saw to be
operated upon.
The angle plate F has a slot H in any convenient part of which a stud J may
be secured by the nut K forming a pivot from which an arm L projects capable of
being clamped upon the pivot at any required angle by the nut M. "The arm L has
a spring N connected thereto at the lower end. This spring terminates in a
socket Por suitable clamp to receive one end of a file Q the other end of which
is grasped by a clamp R from which a guide piece S projects through a slot in
the arm L.
Thus secured in position, the file may be brought more or less near to contact
with the arm L by means of the regulating screw T.
In case the apparatus cannot conveniently be secured in the manner hereinbefore
described by means of the foundation plate A the stud J may be secured in any
convenient angle plate to be secured to some other part of the saw bench such for
instance as to the fence but as a rule in saw benches a slotted opening may be found
in the bench itself upon which the foundation plate A. can be secured in the manner
hereinbefore described.
The apparatus being fixed in position and being regulated so as to bring the face
of the file square with the circular saw and the inclination of the arm L suitable
for the size saw to be operated upon the regulating screw T may be set to bring

page_text: the file in contact with the prominent teeth of the saw which is then to be pulled
round preferably backwards with the teeth travelling in the direction of the length
of the file.
By this means all the more prominent teeth are reduced to the same radial height
as the least prominent teeth and a definite and square outline is produced to guide
the saw sharpener in filing away in opposite directions alternately the parts
of the teeth to be cut away in order to produce an efficient cutting edge.
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. A device for holding files to be employed for producing an outline upon circular
saws as a guide for the sharpening operation capable of regulation horizontally and
vertically substantially as described.
2. In apparatus described by the above claiming clause 1, the combination of the
spring-yielding-file-holder and the regulating screw for following up the cut of the
file till all the saw teeth are reduced to the same radial height substantially as
described.
Dated this 50th day of February 1801
AYRTON & THOMAS,
Patent Agents.