Improvements in Saw-sharpening Machines.
Year: 1889

page_text: Date of Application, 28th May, 1889
Complete Specification Left, 28.h Feb., 1890-Accepted. 29th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Saw-sharpening Machines.
We, ESDAILE & COMPANY Limited, Saw Mill Proprietors, of the City Saw Mills,
Wenlock Road, City Road, and LUCKING CAPPER TAVENER, Saw Sharpener, of
81, Herbert Street, New North Road, both in the County of London, do hereby
declare the nature of this invention to be as follows:-
This invention relates to machinery for sharpening web and circular saws.
In machines as hitherto constructed for sharpening saws it has been necessary
1stly. To take each saw out of the horse or sawholder when only one range of
teeth has been sharpened.
2ndly. To turn the saw round putting it in the horse the reverse way.
3rdly. To alter the position of the hinged arms which carry the emery wheel.
4thly. To turn the emery wheel completely over so as to present the same edge of
the wheel to the reversed saw.
5thly. To alter the angle of the saw carrying horse.
6thly. To adjust the said saw carrying horse by means of an angle gauge.
These six operations involve considerable expenditure both of time and labour.
The main object of our invention is to enable the operator to sharpen both ranges
of a saw without taking it out of the horse. The improvements to gain this end are
hereinafter described and they also comprise a safeguard against the frequent
breaking of the weak end of the rack belonging to the saw carrying horse.
The improvements are as follows:-
We employ reversing strap and pulley motion in place of the single motion
hitherto adopted to cause the emnery wheel to run in either direction.
As the reversed motion of the emery wheel would send the sparks into the operators
face we provide a sheet metal shield which completely confines the sparks to the
vicinity of the wheel and throws them upon the floor and enables the operator
to see his work by having a glass pane in an exact line with the eye and tooth
point.
It is always necessary that the emery wheel should strike the saw tooth at a
mathematically correct distance from the centre line of the said emery wheel each
range of teeth being operated upon from opposite sides and at an equal distance from
the central line of the emery wheel.
This position should also give to the gullets the lead which (together with the angle
formed by topping) would give the cutting point of the tooth.
We meet these requirements in either of two ways viz. -By sliding the whole of
the saw carrying machinery backwards and forwards in a V slide and allowing the
horse and the two slides on which it works to move at set angles on a pivotted base,
or by moving by means of a lever the whole of the uprights and arms which carry
the
emery wheel backwards and forwards in slides so as to bring the emery wheel
when in action to either range of the saw at the same time shifting the angle of the
horse holding the saw as hitherto.
When topping, the saws need to be in a different position from when gulleting.
The lead angle used when gulleting not being wanted for topping. The saws in the
latter case require to be at right angles with the emery wheel at the same time
requiring to be shifted to the back and front of the central line of the wheel for the
different tooth ranges.
For this purpose a pivotted bolt is provided at one side of the machine which
bolt fits into a hole in the under side of one end of the bed of the slides.
When topping the bolt is drawn out allowing the hole of the saw carrying machinery
to be moved uniformly the whole of its longth

page_text: When gulleting, the bolt is held in its place by a pin, fixing one end of the
bed of the slides and allowing the other end only to be moved to the required
angle.
The whole of the shifting is accomplished by simply moving a handle to the right
or left. This handle is fixed to a lever which by a suitable arrangement is attached
to work the whole of these movements. Thus in place of the six separate shifts which
the operator has had to make hitherto, he will now by our invention only have to
make one, viz. to move the lever handle to the right or to the left. To prevent the
end of the rack breaking when rapidly run back after the saw has been sharpened,
stops are placed upon each end of the rack, which stops co.ne unler a boss on the
pinion spindle and so prevent the horse from falling off the slides which unless so
protected it is liable to do.
Dated the 28th day of May 1880
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.
1stly. To take each saw out of the horse or sawholder when only one range of
teeth has been sharpened; and
2ndly. To turn the saw end for end putting it in the horse the reverse way.
3rdly. To alter the position of the hinged arms which carry the emery sharpening
wheel.
4thly. To turn the emery wheel completely over so as to place the edge of the
wheel which sharpened the front range of teeth in position for sharpening the teeth of
the other range.
5thly. To alter the angle of the saw carrying horse, and
6thly. To adjust this angle by means of a gauge.
These six operations involve considerable expenditure both of time and labour.
The main object of our invention is to enable the operator to sharpen both ranges
of a saw without taking it out of the horse and to thereby dispense with several of the
operations before referred to.
According to our invention we provide for driving the sharpening wheel in both
directions, and for moving the horse in a plane so as to adjust the angle of the saw
relatively with the said sharpening wheel.
To enable our invention to be fully understood, we will describe how it can be
carried into practice, by reference to the accompanying drawings, in which
Figure 1 is a front elevation of a saw sharpening machine with our improvements
applied thereto; and
Figures 2 and 3 are a plan and side elevation respectively of the same.
Similar reference letters indicate similar parts throughout the drawings.
a is the frame of the machine, b the horse for holding the saw to be sharpened, the
said horse being adapted to slide upon the guides c, c through the medium of a rack
and pinion d, d' respectively, which latter is connected with a hand wheel d² by
means of which it can be rotated. e is the emery sharpening wheel mounted in
arms which are jointed to a ring " capable of adjustment about its centre in a

page_text: bracket
9,
the said emery wheel being rotated through the medium of a belt passing
around the pulleys h,
All the foregoing parts are of known construction.
The guides c, e carrying the horse b are pivotted at 6' upon a base or turn-table i
arranged to slide backwards and forwards in V-gui les,
upon a bracket
connecting the sides of the frame a of the machine. The said sliling movement of
the base is limited by stops ³, and is effected through the medium of a hand
lever j, a lever k and a rod ¹, the rod A being connected to the rear part of the said
base and extended so as to work in a guide k at the rear of the machine.
12
Pivotted at 1, is a bolt, the point of which is turned up as shewn in figure 1,
so as to be capable of engagement with a hole of correspon ling diameter in the
guides c, c, a pin 13 being placed beneath it to keep it in engagement. By this
arrangement we obtain the angle for giving the lead to the gullets of the teeth of
the saw, that is to say, the point 12 of the bolt acts as a fixed pivot for the horse b,
so that if a saw to be sharpened be fixed in the said horse and the hand-lever j. be
moved, for example, to the right as far as the stops 3, will allow, the said horse,
by reason of it being pivotted to the base i, will be moved so that its centre line m
assumes the position of the dotted line n, figure 2, thereby enabling one range of
the teeth of the said saw to be gulletted at the required angle by the emery wheel
which is brought down upon the saw in the usual manner. To gullet the other
range of teeth, the hand-iever must be moved to the left, the stops, being
previously adjusted so that the centre line m of the horse assumes a position at an
angle relatively with the midway position, corresponding with but opposite to its
position when sharpening the first range of teeth. This angular position is shewn
by the dotted line o figure. 2.
It will be understood that the emery wheel e strikes the saw at a point on its
periphery a short distance to either side of its vertical centre line, according to which
range of teeth is being sharpened, and as it is necessary that the said distances on each
side or the said centre line should be alike, the stops 3 and are adjusted to effect
this.
a
It will also be understood that by this method of gulletting the saw, the emery
wheel e must be revolved as hereinbefore mentioned in one direction for one range of
teeth, and in the opposite direction for the other range. For this purpose we employ
two pulleys p, working loosely upon a shaft and situated one at each side of a
pulleys fixed on the said shaft, to which shaft is also fixed another pulley t which,
by means of a belt, serves to revolve the emery wheel e through the medium of
pulley attached to or forming part of the pulley h. The pulleys p and q are
driven by belts in opposite directions from any suitable source of power, the move-
ment of each belt being imparted to the pulleys as required by strap forks p', q'
arranged respectively over the pulleys p and q, and connected to a sliding bar u
which can be moved to and fro by a striking lever u³, pivotted at u² and con-
nected to the axis of the band-lever ; through the medium of the link j¹ and
lever .
By this arrangement when the hand lever j is operated to allow of
gulletting one range of teeth of the saw as bereinbefore described, one of the
driving straps revolving the pulleys p and q will be moved by its strap fork onto
the pulleys thereby revolving the shaft and consequently the emery wheel e in
one direction. If the hand-lever j be, however, operated to allow of gulletting the
other range of teeth of the saw, the other driving strap will be moved onto the
pulleys and so reverse the movement of the emery wheel.
As the gulletting and topping operations require the emery wheel e to be driven
at different speeds, the pulley is stepped or coned as shewn in figure 2.
Instead of the movable base i, it will be obvious that we can effect the gulletting
operation by arranging the bracket so as to slide backwards and forwards in guides
in order to allow the emery wheel e to operate upon each range of teeth of the saw
in a similar manner to that herein before described, the angle of the horse 6 being
altered for each range.
For topping the teeth of each range it is necessary that the horse be at right angles

page_text: with the emery wheel, as the lead angle used when gulletting is not required for
topping. The saw is, however, moved backwards or forwards to either side of the
vertical centre line of the emery wheel e, for the two ranges of teeth, by means of
the hand-lever j. To enable this backward or forward movement of the saw to be
effected without causing it to assume an angular position as when gulletting, we with-
draw the pin 3 so as to allow the point 12 of the bolt l' to d: op out of engagement
with the guides c, c, and at the same time we fix the horse securely to the base i, to
prevent it turning, by screwing up the lock nut 12 upon the pivot pin b¹.
To prevent the end of the rack d' from breaking and the horse from falling off
the guides c, c when rapidly run back after each saw has been sharpened, stops e, v
are fixed to each end of the said rack, which come against bosses d³ on the spindle d'
of the pinion d².
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. In a machine for sharpening saws, the combination with a sharpening wheel
designed to be rotated in either directions as desired, of a saw holder or horse
adapted to be moved to enable both ranges of the teeth of a saw to be placed at
the proper angle relatively with the said sharpening wheel, substantially as, and for
the purposes, specified.
2. The combination with the holder or horse of a saw sharpening machine, of stops
for limiting the movement of the said horse or holder, substantially as, and for the
purpose, specified.
3. The manufacture and use of the improved saw sharpening machine hereinbefore
described and illustrated in the accompanying drawings.
Dated the 28th day of February 1890.
G: F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.