IMPROVEMENTS IN TOOLS FOR GRINDING AND SHARPENING TWISTED OR OTHER DRILLS
Year: 1878

page_text: LETTERS, PATENT to Martin Benson, of No. 9, Southampton Buildings, London,
for the Invention of "IMPROVEMENTS IN TOOLS FOR GRINDING AND SHARPENING
TWISTED OR OTHER DRILLS." A cominunication from abroad by Alexander
Kirk Rider, of Walden, Orange County, State of New York, United States
of North America.
PROVISIONAL SPECIFICATION left by the said Martin Benson at the Office
of the Commissioners of Patents on the 30th March 1878.
** IMPROVEMENTS
MARTIN BENSON, of No. 9, Southampton Buildings, London.
IN TOOLS FOR GRINDING AND SHARPENING TWISTED OR OTHER DRILLS." A com-
munication from abroad by Alexander Kirk Rider, of Walden, Orange County, in
the State of New York, United States of North America.
The object of my Invention is to provide simple, cheap, and efficient means for
grinding or sharpening twisted or other ordinary drills, whereby the operation can
be performed with the greatest facility and accuracy, and always ensure the most
perfect forin of cutting edge without the employment of skilled and costly labour
for such purposes.

page_text: with a grooved shank C angularly disposed in relation to said perforated face B,
and means for holding the drill within the groove formed in the shank, whereby
the body of the drill may be firmly secured to the shank, and the cutting end of
the drill caused to extend any desired length through the face B of the stock, and
thus allow of the ready and accurate grinding of the drill.
My Invention further consists in a device for grinding and sharpening twisted or
other drills, consisting of a grinding perforated face B provided with a grooved
shank C angularly disposed in relation to said perforated face B, and means for
securing a drill within said shank in such a manner that the drill shall be prevented
from any lateral movement, while it will admit of a predetermined axial movement,
in order that the edges or lips of the drill may be ground in an equal degree, and
always at the same relative angle to each other.
My Invention further consists in a device for grinding and sharpening twisted or
other drills, a perforated grinding plate or face provided with a grooved shank
angularly disposed to said perforated face, a clamp G for securing the drill firmly
within the grooved shank, and a collett H adapted to be removably secured to the
drill, and also to the shank, whereby the drill may be adjustably secured within
said collett H, and the latter adjustably locked to the shank.
My Invention further consists in certain details of construction and combination
of parts for grinding tapered and square-shanked drills, as represented in Figs.
7, 8, and 9. The collett H for these cases are made tapered, and sliped on the
shank of the drill, as represented; the one shown is a round shanked drill. The
collett is secured to the drill in its proper axial relation to its cutting edges for
grinding them to the proper angle. The drill is then placed in the V groove in
the shank of the stock with its end projecting through the opening in the grinding
face B sufficient for sharpening purposes, and then secured to its place by the clamp
G; the resting slide or gauge P is then brought against the collett H, and held to
its place by a screw, as represented, for adjusting the drill longitudinally, so that
cachi lip or side of the drill shall be ground to a uniform length; ordinary square-
shanked drills are ground by the aid of this tool. For such cases the opening in
the collett H is made square to fit over the square shank of the drill.
The stock A, forining the grinding face B and shank C of any of the plans shown,
may be cast or forged solid in one piece, or may be made separate, and secured to
cach other in a ridged or adjustable manner. The grooves D are usually made V.
shaped for receiving the drill, and extended through the grinding face B for some
forms of grinding tools. The groove extends the whole length of the shank C,
while the others, as represented in Figs. 7 and 8, for grinding tapered drills only a
portion of the shank is provided with the V groove.
If desired the shank C may be made of a tube secured to the face B, and pro-
vided with means for clamping the drill, and a collett for holding it in proper axial
position. The grinding face B is hardened to prevent its wearing away by grinding.
When cast it is chilled by casting the face against a piece of metal if desired. The
face B may be cast separate, of hard or chilled metal, and attached by screws or
otherwise to the stock of the grinding tool.
The collett H may be split and clamped to the drill, as shown in Fig. 5, when
used on straight-shanked drills, or made solid and held by a set screw.

page_text: formed in the face B. Opening E extends completely through said face B, and is
gradually contracted in size from the upper to the lower surface of the face. The
V shaped groove formed in the shank, and the diamond shaped opening in the face,
together constitute a continuous V shaped groove for supporting different sized
drills; and the number of different sized drills that can be accommodated by a
single device will depend on the capacity of said groove. Shank C, about midway
its length, is provided with a through slot or opening F, within which is placed
the head of a clamp G, while its screw-threaded shank or stein g projects through
or beyond the lower surface of the shank to allow of the attachment of a suitable
washer and nut b. Clamp G consists of a perforated head e, upon the upper
portion of which is formed an elongated bearing surface d, which is of sufficient
length to overlap one of the spiral cuts or grooves of the drill to be ground or
sharpened, and thus operate to secure the drill firmly in place and prevent any
tendency of the drill to revolve.
The eyee of clamp G is of sufficient size to admit the largest size drill, and it is
obvious that the sinaller sized drills can be firmly secured by the single clamp,
owing to the fact that it is adapted to be adjusted at right angles to the drill.
In the present instance I have illustrated a clamp, wherein the eye c is circular
in form, but it is evident that said eye may be of diamond or any other desired
shape.
H represents a collett. In the present instance it is shown as being made of a
single piece and split on one side through ears or lugs h, each of which have
openings for the reception of a thumbscrew J, as the drill requires to be held
firmly against axial movement in order that the cutting lips may be ground or
sharpened in an accurate manner.
A collett is provided for each size of drill. When the screw J is outwardly
turned the ears separate sufficiently to allow of the adjustment of the drill within
the collett, and by tightening said thumbscrew the drill is securely held in place.
Collett E is provided with two rectangular projections i formed on one end thereof,
and located diametrically opposite each other. The end of the shank is provided
with a corresponding rectangular recess f, within which one of said projections i of
the collett is received when the device is to be used.
The collett serves to admit of the reversal of the drill just one-half of a circle or
revolution, and prevent the endwise movement of the drill in order that the
opposite lips or cutting edges of a drill may be subjected to the same grinding
action, and the same angle of cach lip or cutting edge always be secured.
It will be observed that the collett is adapted and arranged to have a movement
at right angles to the shank in order that different size drills may be firmly seated
within the groove, but the endwise or axial movement of the drill, when the latter
is being sharpened or ground, is effectually prevented by said collett.
The operation of my improved device is as follows:-The drill to be ground or
sharpened is inserted in the V shaped groove and through the eye of the clamp,
Fig. 3, the cutting end caused to project the desired distance below the lower
surface of the face or plate B.
The cutting angle of the entering edge made more or less acute according to the
relative radical position of the edge or lip of the drill relative to the plane of face B,
should the lip coincide with the bottom of the groove a cutting edge of 90° would
be formed, and if placed at right angles to this plane it would result in securing
the most acute cutting angle the device is capable of procuring. It is therefore
easy to impart any desired angle to the cutting edges, as this matter depends solely
on the relative radical position of the edge of the drill to the plane of the face.
The amount to be ground off and the angle of cutting edge being determined,
the drill is securely fastened in its proper position by means of the clamp, the nut
of which is turned down snugly against the washer or surface of the shank. The
collett is then slid over the drill and one of its projections entered into the
rectangular recess in the end of the shank, when the thumbscrew is turned down,
and the collett thus firmly secured to the drill, preventing an axial movement of

page_text: the same.
The face B is then applied to an ordinary grindstone, and the projecting
end of the drill is ground off on the plane with the under surface of said face. The
clamp is now released sufficiently to allow the collett and drill to be withdrawn to
release the projection from the recess in the shank when the collett is given a half
revolution and the opposite projection is entered into said recess.
The clamp is
then secured in place, and the opposite side of the drill is then ground off to a plane
with face B. This operation causes the cutting edges of the drill to be ground to
identically the same form, angle, and length, and gives the advantage of a straight
entering edge, which causes the drill to enter easily, particularly at its centre or
neutral axis.
The grooves D, as before stated, are usually made V shaped for receiving the
drill, and extends the whole length of the shank C; while in other cases, as
represented in Figs. 7, 8, and 9, for grinding tapered shank drills, only a portion of
the shank is provided with the V groove. The shank C in this case is provided
with a slot, in which the stopper P moves for regulating the axial or longitudinal
movement of the drill by engaging with the collett H. The clamp G in this case
for holding the drill to the stock is acted on by a thumb screw from the top of the
tool, as represented in Figs. 7 and 8; a transverse section of the stock is shown by
Fig. 10, through that portion of it to which the clamping device is attached.
The Drawings, Figs. 7, 8, 9, and 10, are sufficiently full to give an understanding
of this part of the improvement to persons skilled in the art without a further
description of the same.
Fig. 11 is a side clevation of the tool, showing the use of the tapered sleeve S
for grinding straight or square-shanked drills. The present arrangement shows the
sleeve in connection with a straight round-shanked drill. The sleeve is inade of
metal and tapered on its outside, as represented, and provided with a bore of tho
right size to receive the drill. The sleeve is split longitudinally at three or more
points at equal distances around its circumference, as represented by Figs. 12
and 13; this is done so that when the collett H is slipped over the sleeve S by
reason of the taper of the outside of the sleeve the collett firmly clamps it to the
shank of the drill. The sleeve S is usually provided with a flange R to engage or
come in contact with the stopper P. Several sleeves may be made to fit the saine
collett, but each a different sized drill or shank, or a collett may be used for straight
shanked drills, as represented in Figs. 14 and 15.
In using sleeve S for grinding square shanked drills the opening in the sleeve is
made square, of the proper size, and split for clamping it to the drill by the tapered
bored collett in the manner before described and represented.
The drill is placed in position for grinding and clamped to the shank of the tool,
after which the sleeve S and collett H is attached to its shank, and the stop P is
placed and secured against the inner end of the sleeve for adjusting the drill in
its longitudinal or axial movement for the purposes and in the manner before
described.
It is evident that slight changes in construction and arrangement of parts may
be adapted without departing from the spirit of iny Invention, as for instance, the
stock may be constructed of two parts and the same be hinged together, whereby
the relative angle formed by the shank and face could be varied as desired. The
shank might be formed of a tube or of side bars, with the outer end provided with
a head having a V shaped groove. Again, instead of using the clamp of the con-
struction shown and described a latch might be hinged or pivoted to the upper
face of the shank and operate to hold the drill in place; or the thumb screw may
be placed above and at one side of the drill, which is the preferred arrangement
when it is required to grind or sharpen very sinall drills. .
The collett may be of angular form and fit within a corresponding angular recess
in the end of the shank, or projections may be formed on the shank and recess for
their reception be made in the collett.
If it is desired to grind or sharpen ordinary drills the collett may be dispensed
with, and the shank is lengthened out to afford the necessary support for the end

page_text: of the drill. The device may also be used to grind up end drills, in which case the
shank is set at nearly right angles with the face. I do not limit myself to the
exact construction shown and described, but. can'to some extent modify the form of
any of the parts of the device without imparing its utility, the general construction
and operation being substantially as above described.
Having now described the nature of my said Invention, and manner of con-
structing and using the same in various modified forms, what I claim is,-
1st. In a device for grinding and sharpening drills a stock for holding the drills,
said stock consisting of a perforated grinding face or plate provided with a grooved
shank angularly disposed relatively to said perforated face or plate, and suitable
means for holding the drill within said grooved shank, substantially as set forth.
2nd. In a device for grinding and sharpening drills a stock for holding the drills,
said stock consisting of a perforated grinding face or plate provided with a shank
having a V shaped groove and means for holding the drill within said groove,
substantially as set forth.
3rd. In a device for grinding and sharpening drills the shank having a groove
formed therein and a through slot at right angles to said groove in connection with
a clamp, which is adapted to fit within said through slot, said clamp serving to hold
the drill firmly in place, substantially as set forth.
4th. In a device for grinding and sharpening drills the perforated face and
grooved shank in combination with means for holding the drill in place, and also
with means to regulate the end and axial adjustment of the drill, substantially as
set forth.
5th. The combination with the grooved shank of a collett adapted to be
adjustably secured to the drill and to the shank, substantially as set forth.
6th. The shank provided with a recessed end in combination with the collett
having two projections, or their equivalent, arranged diametrically opposite cach
other, substantially as set forth.
7th. The collett, provided with a screw or other means to fasten it on the drill,
and also with the projections, or their equivalent, whereby it may be adjustably
secured to the shank, substantially as set forth.
8th. In a device for grinding and sharpening drills the stock, consisting of a.
grinding face and a grooved shank, said face being provided with a diamond or
other shaped openings, into which merges the V groove formed on the shank, sub-
stantially as set forth.
In witness whereof, I, the said Martin Benson, have hereunto set my haud
and scal, this Ninth day of August, in the year of our Lord 1878.