IMPROVEMENTS IN ARRANGEMENTS OR MECHANISM FOR GRINDING OR SHARPENING DRILLS
Year: 1879

page_text: LETTERS PATENT to William Ford Smith and Arthur Coventry, of Gresley Iron
Works, Salford, in the County of Lancaster, Engineers and Tool Makers, for
the Invention of "IMPROVEMENTS IN ARRANGEMENTS OR MECHANISM FOR
GRINDING OR SHARPENING DRILLS."
Sealed the 13th January 1880, and dated the 18th July 1879.
PROVISIONAL SPECIFICATION left by the said William Ford Smith and
Arthur Coventry at the Office of the Commissioners of Patents on the 18th
July 1879.
WILLIAM FORD SMITH and ARTHUR COVENTRY, of Gresley Iron Works, Salford,
in the County of Lancaster, Engineers and Tool Makers. "IMPROVEMENTS IN
ARRANGEMENTS OR MECHANISM FOR GRINDING OR SHARPENING DRILLS."
Our Invention refers to arrangements for grinding or sharpening twist drills.
We prefer to employ an ordinary grinding stone, but our improvements may be
used in combination with composition emery wheels or other grinding wheels.
Our Invention consists of a slide way secured to the frame of the grinding stone;
upon this there is a slide mounted which can be moved by a screw to and from the
grinding face of the stone or wheel, and upon this slide there is another slide which
can move freely across or in a line parallel with the grinding face.
Upon this last named slide there is a bracket secured which forms the bearing of
an axis placed parallel with the grinding face of the stone, and this axis has a head
upon it to form a slide, upon which a lever part can be adjusted to and fro.
This lever part in relation to the axis which carries it is placed in such position
that the drill which is secured on the lever will be ground to the required angle.
In the lever part there is a V groove to hold the drill so as to suit various sizes,
and there is a screw clamp for holding the drill in the V groove.
On the lever there is also an adjustable bracket which forms the bearing for a
hollow collar into which the end of the drill to be ground is placed, and on the
collar there are arrangements for connecting and disconnecting the collar, with stops
to allow the drill, when ground on one side, to be turned one half a revolution to
grind the other side.
When the drill is fixed in the lever holder it is ground by oscillating the lever up
and down by one hand while moving the slide to and fro across the face of the stone

page_text: by the other hand. The V groove in the lever holder is arranged so that when the
drill is clamped in it the axial line of the drill will be below or on one side of the
axis upon which the lever is oscillated.
By this arrangement the drill is ground. to a suitable curve, and with the required
clearance for each cutting edge, and the radius of this curve can be adjusted to the
size of the drill by the adjustment of the lever to and fro on its axis, as before
mentioned.
Our improved arrangements can be applied_to_slides or combined with the same
slides as are used for grinding cutters for planing and turning.
Instead of making the drill oscillate while being ground as above described a part
corresponding to the lever and its attached parts is or may be made stationary in
position, and the grinding stone or wheel is arranged in a swing frame or on a lever
to move in a curve against the drill, and the centres or axis carrying the frame or
lever for the grinding stone are or may be carried on a slide actuated by a screw to
bring the grinding stone to or from the drill, and a slide is or may be used to move
the grinding stone to and fro.
The swing frame or lever of the grinding stone or wheel is on an adjustable axis
or axes, so that the curve described by its movement may be increased or diminished
as required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Ford Smith and Arthur Coventry in the Great Seal Patent
Office on the 14th January 1880.
WILLIAM FORD SMITH and ARTHUR COVENTRY, of Gresley Iron Works, Salford,
in the County of Lancaster, Engineers and Tool Makers. "IMPROVEMENTS IN
ARRANGEMENTS OR MECHANISM FOR GRINDING OR SHARPENING DRILLS."
Our Invention refers to arrangements for grinding or sharpening twist drills.
We prefer to employ an ordinary grinding stone, but our improvements may be used
in combination with composition emery wheels or other grinding wheels.
Our Invention consists of a slide-way secured to the frame of the grinding stone;
upon this there is a slide mounted which can be moved by a screw to and from the
grinding face of the stone or wheel, and upon this slide there is another slide which
can move freely across or in a line parallel with the grinding face.
Upon this last named slide there is a bracket secured which forms the bearing of
an axis placed parallel with the grinding face of the stone, and this axis has a head
upon it to form a slide upon which a lever part can be adjusted to and fro.
This lever part in relation to the axis which carries it is placed in such position
that the drill which is secured on the lever will be ground to the required angle.
In the lever part there is a V groove to hold the drill so as to suit various sizes,
and there is a screw clamp for holding the drill in the V groove.
On the lever there is also an adjustable bracket which forms the bearing for a
hollow collar or tube into which the end of the drill to be ground is placed, and on
the collar or tube there are arrangements for connecting and disconnecting the collar
with stops to allow the drills when ground on one side to be turned one half a revolu-
tion to grind the other side. When the drill is fixed in the lever holder it is ground
by oscillating the lever up and down by one hand while moving the slide to and fro
across the face of the stone by the other hand.
•
The groove in the lever holder is arranged so that when the drill is clamped in
it the axial line of the drill will be below or on one side of the axis upon which the
lever is oscillated.
By this arrangement the drill is ground to a suitable curve and with the required
clearance for each cutting edge, and the radius of the curve can be adjusted to the
size of the drill by the adjustment of the lever to and fro on its axis, as before
mentioned.
Our improved arrangements can be applied to slides or combined with the same
slides as are used for grinding cutters for planing and turning, but we prefer to
arrange and adapt the slides at such angle that the water used in grinding will flow
back from the drill to the trough of the stone, and to combine and arrange the slides
so that they are adapted to receive the apparatus either for grinding twist drills
or other cutters. Instead of making the drill oscillate while being ground as above
described a part corresponding to the lever and its attached parts is or may be made
stationary in position, and the grinding stone or wheel is arranged in a swing
frame or on a lever to move in a curve against the 'drill, and the centres or axis
carrying the frame or lever for the grinding stone are or may be carried on a slide
actuated by a screw to bring the grinding stone to or from the drill, and a slide is
or may be used to move the grinding stone to and fro.
The swing frame or lever of the grinding stone or wheel is on an adjustable axis
or axes, so that the curve described by its movement may be increased or diminished
as required.
Fig. 1 is a side elevation, Fig. 2 a front elevation, and Fig. 3 a plan illustrating
our improved apparatus for grinding twist drills, as applied to a grinding stone.
Fig. 4 is a side and Fig. 5 a front sectional view showing how our improved
arrangements are or may be applied to existing grinding stone troughs, and how our
arrangements of slides for grinding twist drills are adapted for also grinding ordinary
turning and other cutters.

page_text: Fisa Side elevation, Fig.
a cross sectional elevation, Fi
and Fig. 9 a plan of apparatus in which the twist drills are held while being operated
upon.
Fig. 10 is a view of part of the axis and the connected-slide-upon which the drill
holding apparatus oscillates.
Fig. 11 is an elevation of the stand detached which forms the bearing of the axis
of the drill holder.
Fig. 12 is an elevation of the stand shown by Fig. 11, illustrating an alternative
arrangement of the axis to that shown-in-Fig. 9. Figs. 13 and 14 are side views of
chucks or holders which are or may be inserted in the tube for the drill when smaller-
sizes are to be operated upon.
: Fig. 15 illustrates an alternative arrangement of the slide for bringing the tools
to and from the grinding stone.
Fig. 16 is a side elevation, Fig. 17 a front elevation, and Fig. 18 a plan illustrating
a modification of our Invention when a small emery or composition grinding whee!
is to be employed for grinding twist drills Fig. 19 is a side view to illustrate the
movements imparted to the emery wheel.
a is the stand carrying the axis of the handle or lever 6 on which the drill is
secured which is to be ground.
The axis b¹ has a part 6 at an angle from it, which forms a slideway for a
part on the handle which fits it, and the two parts are secured together by a
bolt 6, which passes through a hole in the part b³ and through a slot in the part 6²,
which slot permits the handle to be adjusted to give the required radius according
to the size of the drill to be ground, which adjustment is facilitated by means of an
index on the edge of the part 6³ and a point in b², as shown in Figs. 7 and 10.
The handle part 6 is slotted, as shown in Fig. 9, and planed with a groove in its
face to receive a slide c, as shown in Fig. 6, upon which slide there is a groove for
a cross slide c¹.
The two slides c and c¹ are both secured to the handle (b) by a
bolt c² and wing nut, as shown in Fig. 6.
The slot in the handle b permits of adjustment in the lengthway of the handle
to suit the length of the drill to be sharpened, and there is a slot in the slide c¹
which allows of adjustment across the handle to suit the diameter of the drill.
. The slide c¹ has a tube d fitted in it, with a collar at one end and a screw nut
to form a collar at the other end.
The hole through the tube d is bored out to the same taper as the shank of the
drills to be ground, and when the shank of the drill is firmly forced into the hole,
it is held sufficiently secure by the adhesion of friction and the tube d and drill can
be freely rotated together, and while so free the drill is turned and set to the
correct position for being ground on one side, then the tube d is clamped or secured
by a screw handle d', the screw end of which screws through a hole in a collar d²
that surrounds the tube d, this collar being free to rotate in the fork or space in
the slide c', as shown. The collar d has two holes in its side which are or may be
bushed with steel to prevent wear, these holes being 180 degrees or one half of a
circle apart, and in one of these bushed holes the point of a sliding pin enters,
which pin slides in a hole formed in the slide or stands c¹.
The sliding pin has a helical spring round it which forces its point towards the
collar d², and the point of the pin.is withdrawn from the holes in the collar by a
head d screwed upon the outer end of the pin. The tube d is clamped by the
screw handle d¹.when the point of the pin is in one of the holes in the collar d³,
and this holds the drill secure in that position, and when ground the pin by means
of its head d³ is withdrawn, and the screw handle and collar d² are turned one
half a revolution when the end of the spring pin shoots into the other hole in the
collar (d) and thus the drill is held correctly in that position. The drilling end
of the drill is held in a V groove formed in the side of the handle, and is secured
therein by a flat piece e' secured on the end of a winged screw e, so that the point
of the screw can rotate in a hole in the flat piece (e¹) (see Figs. 6 and 7).
The centre of the V is arranged to bring the axis of the drill a little below the

page_text: axis (6) of the handle; this space between the axis of the drill and handle will
vary with the size of the drill or thickness of the lip of the drill, and may be
obtained if desired by making the handle part 63 slide upon the axis part b² at an
angle which will cause it to rise when the radius is reduced and fall as it increases.
The index, shown in Fig. 10, is for the purpose of adjusting this radius to the size
of drill to be ground.
When in use the handle part b is oscillated up and down on the axis b'; but
instead of the axis 6' carried by the bracket a being arranged, as shown in Fig. 9,
it is or may be arranged as shown in Fig. 12, especially for apparatus to operate
upon large drills, in which case the handle (b), connected parts, and drill will be
heavy and not easy to oscillate.
In Fig. 12 the axis is prolonged through the bearing, and a helical spring b× is
placed upon it, which is secured to the bearing a at one end and to a collar or
washer at the outer end of the axis. This spring b* acts to draw the axis b¹ with
its shoulder against the bearing on the stand a, and it is also made to act so as to
tend to turn the axis b' and thus support and counter-balance the weight of the
handle and make it easier to oscillate it up and down.
Figs. 13 and 14 are views of chucks, holders, or shanks which will fit the tube d;
each chuck or holder has a taper hole formed in it to hold the shanks of smaller
drills.
In Figs. 1, 2, and 3, f is an ordinary grinding stone; g, the stand frame or
trough. In existing troughs a disc or boss part g¹ is secured to the side of the
trough, as illustrated in Fig. 5; but in new troughs this boss or disc is or may be
cast upon the side of the trough. To this boss or disc a slideway h is secured by a
bolt g, which can be turned to the required angle on this bolt g² as a centre and
then secured. The slideway h is placed, at an angle to the horizon parallel to the
line, Fig. 1, upon which the point of the drill comes against the face of the stone,
this angle being such that the water used in grinding will run back from the point
of the drill to the stone and trough and not along the drill as it would do if the
drill was ground at a point of the stone nearer the horizontal line.
The slideway (h) is for a slide h¹, which has a projection from its upper edge at
a right angle to it and parallel to the axis and face of the grinding stone, this
projection forming the slideway for a slide h² that can be moved to and fro by the
handle across and parallel to the face of the stone, and upon the slide a bracket
or stand a is secured (the bracket a, shown in Figs. 9, 11, and 12), which carries
the axis of the handle b, this axis being parallel to the axis of the grinding stone.
In Figs. 1, 2, and 3 the handle b is shown in its lowest position when its underside
rests upon a projection a' from the bracket a
In grinding a drill the handle (b) is moved up and down, and the slide h² is
moved to and fro to traverse the drill across the face of the stone at the same time.
The point of the drill is brought to and from the stone by the screw handle of the
slide h', and the position of this slide moves and keeps the points of the drills
being ground in the line x, Fig. 1, as the stone wears away.
To a projection from the stand or bracket a an arm is jointed, and to this arm
another arm i is jointed that carries the end of a tube i', which is jointed by an
india rubber or other tube with the water can j.
The jointed arm or arms ¿ permit of the tube being adjusted, so that the tube
will discharge the supply of water over the point of the drill being ground to
prevent it from getting heated, and when once adjusted the tube i¹ will move to
and fro with the drill as it is traversed across the face of the stone.
The back of the grinding stone is covered by a hood, the top of which is about
'parallel to the line x, and to the top of the. hood a moveable cap is secured by a
bolt which passes through a slot that permits of adjustment of the cap to the stone
as it wears, so that the front edge of the cap can be kept as the stone wears in
about the same relative position to the drill in which it is shown in Fig. 1.
It is important that the slide h' should move up and down the slideway has the
screw is turned backward and forward; this it might not do always, owing to

page_text: "play" between the screw and its nut; and to ensure the slide h³ moving with the
screw a chain or rope is connected with the slide h' and is passed over pulleys h
and-h,-and-a-weight.his suspended, as shown in Fig. 4, the weight acting to pull
the slide (¹) up the slide way, Instead of using-a-weight-this_object may be
accomplished by the arrangement illustrated by Fig. 15, a sectional view of the
slideway h, slide h¹, and screw_ht. The screw has a collar upon it, and between
this collar and a boss.h there is a helical spring h. The boss is secured to the
slideway h by screws, and the spring his pressed and held with the desired force
against the collar of-the-screw-h-to-keep the screw from sliding outwards except
in the case of excessive pressure.
The screw * screws through a nut h* secured to or connected with the slide h¹
by a projection passing through a hole in the slide, as shown; the screw also screws
through another adjustable nut 10, a round nut having several longitudinal grooves
on its exterior. Between the two nuts h* and h¹ there is an helical spring h", and
it is by turning the adjustable nut that the required pressure can be put upon the
spring h¹.
The nut 10 is prevented from revolving with the screw ' by a projection, which
enters one of the grooves on the exterior of the nut, which projection secured by
a set screw 12 to the slide h¹.
The spring thus arranged prevents the "play" between the nut h* and
screw In Fig. 4 the slides are the same as those shown in Figs. 1, 2, and 3,
but the bracket or stand a is unscrewed from the slide h2, and a stand k is secured
in its place, which stand has a bolt ¹ to secure another bracket ², which can be
adjusted to any desired angle.
This last named bracket (²) has a screw clamp 3 for securing holders ¼ for any
cutters requiring to be ground.
By this arrangement the same slides and stone are used for grinding or sharpening
both twist drills and other cutters.
Figs. 10, 17, 18, and 19 illustrate a modification of our Invention, where an
emery or other composition wheel is used for grinding or sharpening twist drills,
the drill when operated upon being held stationary while the emery wheel as it
revolves is moved in a curve against the edge of the drill. is the stand or frame,
upon which there are slide-ways for two horizontal slides, one of them moving at
a right angle to the other. An upright projection from the slide m forms a bearing
for a short shaft n¹ forming the axis of the lever handle n.
The short shaft n¹ has a cross piece n² provided with grooves to receive the
lever handle n, which is secured thereto by a screw n³ passing through a slot in
the lever handle that permits it to be adjusted to and fro.
The end of the lever n forms the bearing for the shaft p' of the emery wheel p,
which shaft has also a pulley p² secured to it for the driving band, one side passing
under one pulley 9 in going to the pulley p², and the other side under the pulley q¹
in returning from-the-pulley_p? These pulleys q and q' rotate freely on the end
of the projecting end of the axis n' of the lever n, or on a separate stud..
---
They may be placed on a stud in the end of the vertical arm of a bell crank
lever, the horizontal arm being acted upon by a weight or spring, the fulcrum of
the bell crank lever being carried on a projection from the slide m thus arranged
the driving band will not go slack and tight in working, but will be kept at uniform
tension, while allowing the emery wheel to be oscillated up and down.
When the pulleys 2 and q¹ are fixed in position a pulley on a lever may be
pressed by a spring or weight against the driving band in any convenient position
between the pulley on the emery wheel shaft and the pulley driving the band.
On the slider there is fixed or formed a stand b that corresponds to the lever
handle b, Fig. 6, except that it is fixed in position on the slide r. This stand
carries the parts herein before described as secured upon the handle b, in which
parts the drill is held or clamped to be ground, and is then turned half round to
present, the other edge of the drill to be operated upon. While being ground the
slider is moved to and fro to cause the drill to traverse over the face of the emery

page_text: wheel p, at the same time the handle n is moved up and down to oscillate the
emery wheel against the end of the drill.
The emery wheel p is adjusted to the drill by the screw handle m² of the slide m.
The position of the axis of the drill in relation to the axis n¹ of the lever n for the
emery wheel is similar to what it is shown in Fig. 7, so that cutting clearance will
be given by the curve to which the end of the drill is ground.
We have now particularly described the nature of our Invention and the manner
in which the same is to be carried into effect, and claim as our Invention,-
Firstly. The system or mode of grinding or sharpening twist drills by arranging
the same in holding mechanism on a lever or handle (b), which is mounted on an
axis (6), so that the drill may be oscillated on such axis with the point against
the face of the grinding stone or wheel, substantially as hereinbefore described and
illustrated by the Drawings.
Secondly. Arranging the axis of the drill in the holding mechanism so as to be
above or below or upon one side of the axis (6¹), upon which the handle or lever (b)
oscillates to give clearance to the cutting edge of the drill, substantially as herein-
before described and illustrated by the Drawings.
Thirdly. The counter-balancing the weight of the handle or lever (6) and con-
nected parts by a spring, substantially as hereinbefore described and illustrated by
Fig. 12 of the Drawings.
Fourthly. The arrangement of the slides (h' and h²) in the angular position in
relation to the grinding stone or wheel, substantially as herein before described and
illustrated by Figs. 1, 2, and 3 of the Drawings.
Fifthly. The arrangements for taking away "play" between the screw (h) and
nut (h) of the slide (¹), substantially as hereinbefore described and illustrated by
Figs. 4 and 15 of the Drawings.
Sixthly. The general combination and arrangement of mechanism for grinding
twist drills, substantially as hereinbefore described and illustrated by Figs. 1 to 15
inclusive of the Drawings.
Seventhly. The combination and arrangement of the slides (h' and h²), so that
the same slides are adapted and can be used both for grinding twist drills and other
cutters, substantially as hereinbefore described and illustrated by Fig. 4 of the
Drawings.
Eighthly. The arrangement of the hook (75) and cap (5), substantially as herein-
before described and illustrated by the Drawings.
Ninthly. The system or mode of grinding or sharpening twist drills when the
drill is arranged in holding mechanism and the grinding wheel is oscillated against
the end of the drill, substantially as hereinbefore described and illustrated by the
Drawings.
Tenthly. The combination and arrangement of mechanism for grinding or
sharpening twist drills, as hereinbefore described and illustrated by Figs. 16 to 19
inclusive of the Drawings.
In witness whereof, I, the said Arthur Coventry, on my own behalf and on
behalf of the said William Ford Smith, have hereunto set my hand and seal,
this Thirtieth day of December, in the year of our Lord One thousand
eight hundred and seventy nine.