Year: 1885

page_text: I, FRANCIS BUTTERFIELD of Midland Works Keighley in the County of York,
Engineer do hereby declare the nature of this invention to be as follows:-
This invention relates to holders for revolving cutting tools such as twist and
other drills for which it is chiefly designed, and its object is to furnish a holder or
apparatus by means of which the tool may be easily and quickly secured in
position, concentric with the axis of the spindle of the machine, and so that the
tool may be formed without a specially formed head allowing of its being inserted
into the holder for any given distance and used so long as there is sufficient length
of tool to provide a grip for the holder, and to cut the depth of hole required.
It consists essentially of a holder of taper, square or other shape, on the outside
corresponding with the internal section of the spindle of the machine into which
it fits, provided internally throughout its length with a hole of about the size of
the tool and fitted at the end with a nut having a conical sleeve or portion which
by compressing a series of pins or wedges secures the tool in position.
In carrying out the invention the tool is formed of parallel tool steel, preferably
round or cylindrical, and in the case of a twist drill cut preferably with three
twist grooves from end to end, these grooves being in cross section equidistant
from each other. The tool holder is formed externally at one end of any suitable
cross section, circular, square or other, and parallel or tapered to correspond with
the socket of the machine spindle into which it is to fit. A hole is bored or
otherwise cut longitudinally through the centre of the holder for its entire length
to receive the tool. This hole may be slightly larger than the diameter of the tool,
so that the latter may be easily inserted and withdrawn. The spindle of the
machine should be made hollow for a greater distance than the socket into which
the holder fits, in order to allow room for receiving a tool of considerable height,
the end projecting up through the holder. The other end of the holder is screwed
to receive a nut, but sufficient of the thread is turned off to allow of holes being
drilled for three or more or less steady pins to be put through, each pin to fit into
one of the twist grooves in the drill. The nut is made to screw upon the holder,
and is made with a plain unscrewed portion which is slightly taper, so that when
the nut is screwed up the taper portion gradually presses each of the steady pins

page_text: into their respective grooves, and so accurately and securely fixes the drill. These
steady pins are supplied with a small spring to relieve the pressure upon the drill
when the nut is unscrewed.
When the holder is designed for a tool other than a twist drill, the steady pins
will be replaced by wedges fitted into slots or placed inside the nut below the end
of the screw on the socket of the holder, the wedges being inserted between the
tapered part of the nut and the tool. These wedges, which may be of steel, brass,
zinc, wood vulcanite or other suitable material are formed out of a truly bored and
turned cone, cut into three, or other number of segments. These conical segments
or wedges, abut against the end of the holder, and when the nut is screwed up
upon it, are by the advance of the cone tightly compressed upon the drill, thereby
fixing it firmly and concentrically in position.
With a holder of this construction a long twist drill or other cutting tool can be
used requiring no end preparing upon it for the socket of the spindle of the
machine which is most important in cutting cotter holes key, groove and slotting
generally.
This arrangement effects not only a reduction in first cost, but prevents
subsequent waste, as the drill can be used as long as a sufficient length of it.is
left to drill the depth of hole required. Greater strength and steadiness is also in
many instances, imparted, as the tool may be set with no more projection out of
the holder than is required for the work in hand.

page_text: Improvements in Holders for Twist Drills and other
similar Tools.
I, FRANCIS BUTTERFIELD, of Midland Works; Keighley, in the County of York;
Engineer, 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 holders for revolving cutting tools, such as twist, and
other drills for which it is chiefly designed, and its object is to furnish a bolder or
apparatus by means of which the tool may be easily and quickly secured in
position, concentric with the axis of the spindle of the machine, and so that the
tool may be formed without a specially formed head, allowing of its being inserted
into the holder for any given distance, and used so long as there is sufficient length
of tool to provide a grip for the holder, and to cut the depth of hole required.
It consists essentially of a holder of taper, square, or other shape, on the outside
corresponding with the internal section of the spindle of the machine into which it
fits, provided internally with a hole of suitable size for tool, and fitted at the end
with a nut having a conical or wedge shaped sleeve or portion, which by com-
pressing a series of pins or wedges secures the tool in position.
It is best described by aid of the accompanying drawings:
Figure 1 is a longitudinal section, and
Figure 2 transverse section of holder constructed according to my invention.
Figure 3 is an elevation.
Figure 4 longitudinal section, and
Figure 5 transverse section of holder shewing twist drill in position, and the
position of the springs.
Figure 6 is an elevation.
Figure 7 longitudinal section.
Figure 8 transverse section of holder with the securing nut inclined or wedge
shaped in a circular instead of a longitudinal direction.
Figure 9 end plate, H.
Figure 10 longitudinal section, and
c.
J
J
Figure 11, transverse section of similar holder shewing twist drill in position.
In these A is the body of the holder, B the tool formed from parallel tool steel
preferably round or cylindrical, cut preferably with three twist grooves from end to.
end, these grooves being in cross section equidistant from each other. The tool
holder A is formed externally at the end a of any suitable cross section, circular,
square or other, and parallel or tapered to correspond with the socket of the
machine spindle into which it is to it. It is bored or otherwise cut longitudinally
to receive the tool. The hole D so cut may be larger than the diameter of the tool-
to allow of its being easily inserted and withdrawn, or of tools of several siges
being used with one holder. The spindle of the machine which carries, the;
holder A should be made hollow for a greater distance than the socket into.
which the end a of the holder fits in order to allow room for receiving a tool of

page_text: considerable height, the end projecting up through the holder. The other end of
the holder is preferably somewhat enlarged and screwed at a¹ to receive a nut E.
The extreme end of the bolder is preferably made without the screw threads, and
may be finished conical or cylindrical as desired. In this part of the holder are
drilled one, two, or more holes F preferably three, in which are placed steady
pins G. These pins pass through the holes, their inner ends abutting against the
tools, and where twisted or fluted tools are used, fit into the flutes or grooves of the
tool. The nut E is cut or formed internally with screw thread at one end e to
correspond with the external screw on the holder, and at the other end e¹ is made
wedge-shaped. The wedge-shaped portion presses against the outer ends of the
pins G, so that as the nut is screwed up, it gradually presses each of the steady
pins against the tool, or into the grooves formed therein, and so accurately and
securely fixes the drill. In Figures 1 and 4, the end e¹ of the nut E is shown
inclined or tapered longitudinally, the longitudinal motion of the nut, acting to
force the pins against the tool. In Figures 7, 8, 10 and 11, the end e¹ of the nut
is formed with the wedges or inclines placed transversely, the angular motion of
the nut acting to force the pins against the tool. The screw thread may be
dispensed with to keep the nut in position, a ring may be used instead of the nut,
having only an angular motion, which when turned will bring the inclines against
the pins, and force the pins inwards as shewn in the Figures. In cross section, the
pins G may be either circular or oblong according to the required amount of
bearing surface. In Figures 7, 8, 10 and 11, the holes F are cut in the face of the
holder, and the pins G are secured in position by means of a plate H screwed
thereto. In Figures 1 and 7 pins G are shown oblong, and may be curved on top
to bring the bearing surface to the centre, or may be inclined to meet the surface of
the nut, and to increase the bearing surface. For twist drills I prefer circular pins,
but for other tools I prefer them oblong and wedge-shaped. The steady pins G
may be supplied with a small spring g to relieve the pressure upon the tool when
the nut is unscrewed.
It is obvious that the steady pins may be replaced by their mechanical equivalents
such as wedges fitted into slots or placed inside the nut below the end of the screw
on the socket of the holder, the wedges being inserted between the tapered part of
the end and the tool. These wedges, which may be of steel, brass, zinc, wood
vulcanite, or other suitable material are formed out of a truly bored and turned
cone, cut into three or other number of segments. These conical segments or
wedges abut against the end of the holder, and when the nut is screwed up upon
it, are by the advance of the cone tightly compressed upon the drill, thereby fixing
it firmly and concentrically in position.
With a holder of this construction, a long twist drill or other cutting tool can be
used, requiring no end preparing upon it for the socket of the spindle of the
machine, or for the socket of a holder, which is most important in cutting cotter
holes, key, groove, and slotting generally, as the tool can be clamped close to the
end, which performs the work, greatly reducing the leverage acting to bend or
break the tool.
This arrangement effects not only a reduction in first cost, but prevents
subsequent waste, as the drill can be used as long as a sufficient length of it is
left to drill the depth of hole required. Greater strength and steadiness is also in
many instances imparted, as the tool may be set with no more projection out of the
holder than is required for the work in hand.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
-
1. A holder for revolving cutting tools such as straight, grooved or other form of
twist drills, having one, two, or more preferably three pins or wedge shaped pieces
forced tightly against the tool, by means of a nut screwed over them, substantially.
as described,

page_text: 2. A holder for twist drills or similar tools, bored longitudinally its entire length,
having pins or wedges fitting into and sliding on holes or slots in combination with
a nut or ring, inclined or tapering internally, so that as it is screwed, turned, or
forced down over the pins or wedges, the latter are forced against the tool holding
it fast.
3. A holder for revolving cutters and other tools bored longitudinally, fitted at
one end for the socket of a machine, and chased at the other end to receive a nut
which abuts against one or more pins or wedges and forces them tightly against the
tool, to be secured, substantially as described.
4. A holder for twist drills and other tools constructed substantially as described
and shown.