Improvements in Machines for Making Twist-drills.
Year: 1895

page_text: Date of Application, 28th May, 1895-Accepted, 25th Jan., 1896
COMPLETE SPECIFICATION.
Improvements in Machines for Making Twist-drills.
I, MOSES CARLYLE JOHNSON, of Number 19 Congress Street, in the City of
Hartford, County of Hartford, and State of Connecticut, United States of
America, Mechanical 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 :-
The object of my invention is to provide a machine by means of which au
improved twist drill may be manufactured, the machine combining means for
producing a twist drill with a groove of any desired pitch and depth, and
consequent thickness of web.
To this end my invention consists in the details of the several parts making up
the machine as a whole and in the combination of such parts as more particularly
hereinafter described and pointed out in the claims.
Referring to the accompanying drawings:
Figure 1 is a view in front elevation of my improved machine with the hand
wheel shaft cut in section.
Figure 2 is a view in rear elevation of the machine.
Figure 3 is a view in side elevation of the machine with parts broken away to
show construction.
Figure 4 is a top or plan view of the machine, one side being cut in section
through the axis of the driving worm shaft and of the cutter spindle.
Figure 5 is a perspective view of the lower part of the machine.
Figure 6 is a detail top view in section through the cutter head in the axis of
the driving worm shaft and of the cutter spindle showing the manner of pivoting
said cutter head to the top slide, and the relation of the cutter and pivot.
Figure 7 is a detail end view of the top slide and cutter head showing the means
for giving vertical movement to the latter.
Figure 8 is a detail front view in section through the pivot of the cutter head
showing the relation of the cutter to said pivot.
Figure 9 is a detail front view of the web slides for varying the distance between
the cutters.
Figure 10 is a detail view in section through one of the web slides showing its
contact with the cutter head slide.
Figure 11 is a view in horizontal section through the machine on a line just
above the clutch shaft, looking down.
Figure 12 is a like view on a line between the clutch shaft and equalizing shaft,
and immediately above the latter.
Figure 13 is a like view on a line just underneath the casings for the releasing
rods.
Figure 14 is a diagram view, in perspective, showing the connections between
the several parts composing the clutch shaft operating mechanism, and their.
relative relation to each other and to the clutch shaft.
It has been determined by thorough test that the greatest advantages, and
consequently the least disadvantages, are present in a twist drill having grooves of
uniform pitch from point to shank, the groove decreasing in depth and the web
consequently increasing in thickness from point to shank, and the within described
machine is particularly adapted for producing that form of twist drill.
There is embodied in the machine means for holding the drill blank, for rotating
it, and for cutting grooves in diametrically opposite sides of the blank, the cutters

page_text: during the process of cutting changing their angle of inclination with respect to
the axis of the drill blank, which has a lengthwise feeding motion across the
cutters. The cutters are arranged on diametrically opposite sides of the blank
and are movable directly outward and away from the axis of the drill blank for
the purpose of decreasing the depth of the groove and increasing the thickness
of the web, the latter being that part of the drill included between the bottom
surfaces of the grooves. The mere withdrawal of the mills would decrease the
depth of the grooves, but would at the same time decrease the width, and in order
to maintain a substantially uniform width of groove from point to shauk, which is
an important feature, the cutter is caused to change its angular position with
reference to the axis of the drill and in this manner maintain the required
uniformity of width of groove along its whole length.
When the cutter is in contact with the blank in the operation of cutting, a line
extended at right angles to the axis of the blank and diametrically through the
cutter will represent the axis on which the cutter moves when changing its angular
relation to the drill, and it is evident that a pivotal point of support for the
cutter in prolongation of this axial line must be provided. One form of providing
this change in the angular relation of the cutter with respect to the axis of the
drill during the cutting of the grooves is embodied and illustrated in the within
application.
In the drawings forming a part hereof the letter A denotes the standard, B.the
base of the machine, B the side posts, B2 the top piece, B³ the cross-piece,
and B the bottom piece.
Near the upper end of the posts B' is supported a swinging bracket a, pivoted
to one of the side posts, and on this swinging bracket is supported a fixed stud al
bearing a pulley a' that is driven by means of a belt from any suitable source of
power and by means of which rotary movement is imparted through means of inter-
meshing gears to the worm shaft a bearing a worm in mesh with a worm gear a
This worm gear at is secured to an interior screw threaded sleeve that extends
upward and has a bearing in the top piece B2, and to the upper end of this sleeve
is secured the gear as by means of which, through a series of gears of any desired
number, movement is imparted to the vertical shaft a. A bevel gear is also
secured to the under side of the worm gear a and is in mesh with the bevel
gear a supported on the shaft bearing the hand wheel aº. The sleeve to which
this worm gear a' is secured, or of which it forms a part, is screw threaded on its
interior surface and fits the screw threaded portion of the blank holding
shaft h.
The rotation of the worm gear a and consequently the interior screw threaded
sleeve, above referred to, imparts to the blank holding shaft b a vertical movement
through the medium of the screw threaded part 6¹ of said shaft fitting the interior
screw threaded sleeve. The shaft a bears on its lower end a bevel gear a in
mesh with a clutch shaft driving gear secured to the clutch shaft c.
This
clutch shaft c bears a worm that is in mesh with the worm gear secured to
the blank holding shaft b. The clutch shaft c has a comparatively slow rotation,
and through the medium of worms and gears just described a rotary motion is
imparted to the blank holding shaft b and consequently to the blank held therein
at its lower end.
A more detailed description of this part of the machine has been omitted for
the reason that it is old and well known in inachines of this class, and no claim
whatever is made herein to this part of the invention.
с
The clutch shaft c is mounted in suitable bearings B' on the side-posts B¹. On
this shaft the clutch-worms c are loosely mounted and the clutch sleeves are
splined to the shaft in such manner as to be held against rotation thereon, but to
have a free lengthwise movement to enable the teeth thereon to engage the teeth
on the clutch worms. There is also secured to these clutch-worms to rotate there-
with the equalizing-shaft-driving-gears c³. One end of each of the releasing
yokes d¹ is secured to a clutch-sleeve in such manner as to allow the latter to

page_text: otate freely but have no lengthwise movement therein. The other ends of these
sleeves are secured to the releasing rods d that are located in casings B in such
manner as to have a free lengthwise movement therein. The equalizing shaft
bearings are pivoted upon the releasing rod casings B or upon the side parts of
the frame of the machine in such manner as to have a movement to and from the
clutch shaft and in the outer ends of these equalizing shaft bearings e is
mounted the equalizing shaft d³ to which are secured the equalizing shaft gears d
in mesh with the equalizing shaft driving gears c³. On the inner ends of the
releasing rods are pivoted the links do, the opposite ends of these links being
pivoted to the slide located in the slide-way on the cross-piece B³. To this
slide d is also pivoted one end of the slide operating link d', the opposite end of
this link being secured to the slide operating rod that extends through the
cross-piece B to the front of the machine, the mechanism above described being
located on the rear of the machine. To the opposite end of the slide operating
rod d, at the front of the machine is secured the clutch hand lever do, the inner
end of this lever being adapted to engage the latch d" pivoted to the cross-
piece B. The clutch hand lever is provided on its upper side with a
extension do of such length as to constantly engage the latch d" when the hook
on the lower end of the latter is forced out of engagement with the clutch hand
lever and the latter forced downward under the impulse of the spring plunger d".
located in a socket on the machine, a spring tending to force the plunger normally
downward. This spring plunger operates to force the slide downward upon the
release of the clutch band lever from engagement with the latch as by raising the
outer end of the latter; the clutch parts are held in engagement when the slide d
is at the upper limit of its play.
cam
It is obvious that the cutter heads K, hereinafter referred to, bearing the cutters
should be maintained in the same relative position and lifted or depressed simul-
taneously in order to enable a drill blank to be equally cut on each side, and the
object of the construction of the equalizing shaft above described is to enable this
result to be attained. This equalizing shaft d' connects the clutch worms c* through
the medium of the gears compelling both clutch worms to turn together, these
clutch worms being in engagement with the elevating shafts E that lift or depress
the cutter heads K. If the clutch worms c¹ were not thus connected, when the
clutch parts are thrown out of engagement the clutch worms would be loose on thę
shaft and a jar or other cause would be liable to rotate the same throwing the cutter
head connected thereto out of its relative position with the opposite cutter head, and
the construction above described obviates such a fault.
Bearings B' for the elevating shafts are secured to the side parts Bland in these
bearings are journalled the upper sections e of the elevating shafts E. Secured to
these upper sections e are worm-gears e¹ in mesh with the worms c on the clutch
shaft c.
The extensible sections e2 of the elevating shafts. E are secured to the
upper sections by means of a ball and socket joint, the lower half of the extensible
section being splined within the upper half in such manner as to compel the two
sections to rotate together but to have a sliding movement one within the other,
the lower end of the extensible section e" being secured to the elevating worm
shafts e³ by means of a ball and socket joint, as above described. These elevating
worm shafts bear elevating worms e, Figure 7, in mesh with a segmental gear K
located on the elevating head hereinafter described.
On the top slides are located the bearings f¹ for the elevating worm shafts e³,
and there is also secured to said top slides, preferably integral therewith, the head
supports. The top slides fare adjustably secured to the intermediate slides by
means of bolts passing through slotted openings f³ in the top slides, the top slides
being adjustable on the intermediate slides in a line lengthwise of the cutter spindle.
Each intermediate slide g has dove-tailed projections on its under side adapted to
5 fit a dove-tailed groove in the upper part of the bottom slides h. These butto.n
slides have also located on their undersides dove-tailed grooves adapted to receive
the dove-tailed projection on the upper side of the slide bases, the latter being

page_text: secured to the base B. The bottom slides are movable on the slide bases laterally
of the machine, and the intermediate slides are movable on the bottom slides also
laterally of the machine, the several slides being provided with intermeshing screws
and nuts for securing any desired degree of movement one upon the other, and the
adjacent surfaces of the moving parts are provided with graduations whereby fine
adjustments of the slides one upon the other may be secured.
In the head supports are bevel openings within which are located the cutter
head joints extending beyond the surface of the head supports and provided
with central holes for the reception of the retaining screws f. The cutter heads K
have on their inner ends sockets k within which fit one end of the cutter head
joints, and centrally of this socket kis the screw threaded opening k¹ for the
reception of the retaining screws f³, this construction of the joints affording a
means of securing the parts together that prevents any rocking or sidewise
movement whatever of the one part upon the other. These cutter-heads K are
provided with projections or bearings k, k³, for the cutter spindles l.
These cutter spindles are provided on their lower ends with any suitable means
of attachment thereto of the cutters, preferably being screw threaded, and the
cutters are secured to the spindles by means of nuts fitting the end of the spindles.
Each cutter spindle has a bevel portion fitting within the bevel socket in the
cutter bearings, and on the upper side of this bearing and secured to the
spindle as by a key is a collar 1, and on a threaded portion of the spindle adjacent
to this collar a lock nut 1. In the bearings are sleeves 1, the lower ends of
which are screw threaded and bear nuts 1º, these several collars and nuts just
described affording a means of taking up any wear and preventing the spindle from
any lateral or longitudinal movement within the bearings. To the cutter spindle
is secured the worm gear, the spindle drivers fitting upon the end of the spindle /
and being secured to the worm gear as by means of screws passing through the
spindle-drivers into the worm gears, the spindle drivers being secured to the
spindles as by means of pins passing through and through the several parts. On
the upper ends of the cutter heads are located the spindle driving shaft bearings m
within which are journalled the spindle driving shafts m¹ bearing on their outer ends
the spindle driving worms m². On the opposite end of each spindle driving shaft is
borne the driving gear m³ secured to the driving collar m³ fitting over the end of
the driving shaft, and secured to the gear as by means of screws passing through
the former into the latter, is the collar, in turn being secured to the driving shaft
by means of a key or of a pin passing through the parts.
On the base B are secured swinging frame bases a within which are pivoted the
swinging frames n', the upper ends of the swinging frames branching outward and
forming bearings for the driving shafts n². On these driving shafts n are secured
the driving gears n³ in mesh with the spindle driving gears m³ on the spindle driving
shafts m. Yokes mare secured to the shafts n² and m¹ respectively in such manner
as to allow the shafts to rotate freely therein, the object of the yokes being to keep
the gears m and n² continually in mesh with each other, the swinging frames i
allowing the gears to move to or away from the machine as the cutter heads are
elevated or depressed. To the driving shafts n are secured the pulleys n³ adapted
to receive a belt extending from any suitable source of power and furnishing means
for driving the cutter spindles and cutters attached thereto.
The front edges of the cutter head supports f' are formed in the arc of a circle
struck from the center of the cutter head joints f, and a projection extends
outward from each of the cutter heads a distance equal to the thickness of the cutter
head supports f, the edge of this projection adjacent to the head supports being
formed in the same arc of a circle as the edge of said head support. Elevating
head gibs are secured to the projections in such manner as to extend some
distance inward along the head supports 2 on the side opposite from the body of
the cutter heads K.
The web yoke o is secured to the blank holding shaft and its opposite ends
extend on opposite sides of the posts B¹. Web slides o' project downward from

page_text: each end of said web yokes through openings in the top slides f, these web slides
having their upper ends inclined outward to give to the top slides fa movement
away from and toward the blank feeding shaft as the web yoke o moves downward.
and upward. A vertical shipping rod is also secured to one end of the web yoke
and extends upward to engage the swinging bracket a to throw the mechanism.
thereon out of engagement with the other parts of the machine and stop its
A fuller and detailed
operation at predetermined positions of the web yoke o.
description of these parts is deemed unnecessary herein as they are of old and well
known construction in prior machines of this class.
A clutch disengaging rod p is adjustably secured in a socket in the front of the
web yoke o, the upper end of this rod having adjustably secured thereto the
engaging and disengaging rod yoke p¹, and to this yoke is secured the engaging
rod pa the upper end of which bears a trip p³ adapted to engage a pin d¹³ on the
latch d. The clutch disengaging rod p is secured to the web yoke so that its.
upper end will strike the clutch hand lever at a certain time and throw it upward
allowing the latch d" to fall by gravity into engagement therewith and hold it in
this position, and the engaging rod is so adjusted as to trip the latch at a certain
time and allow the hand-lever to fall, the first described movement of the clutch
hand-lever throwing the clutch parts into engagement with, and the second described
movement throwing them out of engagement with the clutch-shaft c.
The operation of the machine briefly stated is as follows:-
The parts being in the position shown in Figures 1 and 2, a drill-blank is inserted.
in the lower end of said shaft b and the device started by throwing the bracket a
This.
inward so that the worm on the worm-shaft a' engages the worm-gear a*.
starts the entire mechanism, the revolution of the interior threaded sleeve secured.
to the worm-gear a causing the shaft b and the yoke o secured thereto to be fed
downward by means of the thread b' on the upper end of the shaft b. The rotation
of the vertical shaft a causes the shaft c to turn, and the worm c² thereon, meshing.
with the worm-gear secured to shaft b, causes the latter to be slowly rotated to
The clutches on the
cut a spiral groove in the blank secured at its lower end.
outer end of shat e being in engagement with the clutches on the worms c, said.
worms are rotated, and consequently the shafts e². This operation elevates the
heads bearing the cutters, which operation causes the width of the groove in the
blank to be maintained as the cutters are moved apart. The cutters are moved
apart by the action of the web-slides o' on the top slides bearing the cutters.
The cutters are rotated by the operation of the shaft n³ in engagement with
the shaft m', the latter being operatively connected to the spindle bearing the
cutters l.
In the downward movement of the shaft b and yoke o at a time determined by
the adjustment of the parts p, p', and p³, the trip is caused to engage the pin da.
on the latch throwing the lower end of the latch outward and allowing the inner
end of the clutch hand-lever d to fall downward. This rotates the slide operating
rod d which throws the slide de downward and the releasing rods d outward,
disengaging the clutches from the worm c and stopping the elevation of the
cutter-heads.
When the drill is completed, that is to say, when the blank-holding-shaft b has
reached the lower end of its travel and the several sets of feed-mechanism are
automatically thrown out of gear as above described, the clutches controlling the
worms are again thrown into gear by means of the clutch-haud-lever do, and the
blank-holding-shaft bis raised by means of the hand-wheel a so as to bring the parts
to their original positions, the swinging-bracket a meanwhile remaining in its
outward position, i.e. with the worm out of engagement with the worm-wheel a*.
When the completed drill is removed and a fresh blank secured in position in
the shaft b, the swinging bracket a may be brought into its inward position, and
the various parts again set in motion to operate as above described.
There has been described herein one form of mechanism for accomplishing a
movement of the cutters away from the drill-blank and at the same time rotating

page_text: or tipping the cutters on an axis formed in the line of a diameter thereof, at the
same time that the drill blank is fed downward and also rotated, but it is obvious
that other mechanisms may be employed for accomplishing the same result
without departing from my invention.
An important feature of my invention consists in the combination of mechanisms
and means whereby the angular relation of the axis of the drill-blank to the plane
of the cutter, or to that line which has been described as the circumferential axis
of the cutter, may be changed. The result of the change of the angular relation of
the plane of the cutter to the axis of the drill-blank enables the width of the
groove to be maintained as the groove is being cut in the substance of the
drill-blank, and while the cutters are drawn back to give increased thickness
of web.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is
1. In combination with a blank holding shaft and means for operating the same,
a cutter supported in operative relation thereto, means for automatically swinging
the cutter on a diametrical axis, and means for automatically rotating the cutter on
a circumferential axis simultaneously with its movement on the diametrical axis, all
substantially as described.
2. In combination with a blank holding shaft and means for operating the same,
cutters supported in operative relation thereto, means for simultaneously rotating
the cutters on a circumferential axis, and means for automatically swinging the
cutters on a diametrical axis in a line transversely to the axis of the black
holding shaft and simultaneously with their rotation on a circumferential.axis, all
substantially as described.
3. In combination in a drill making machine, a frame supporting therein a blank
holding shaft, means for operating said shaft, a cutter head pivoted transversely to
the axis of the blank holding shaft, means for automatically swinging the cutter
head on its pivot, the cutter spindle borne in the cutter head, and means for
automatically rotating the spindle simultaneously with the swinging movement of
the cutter heads, all substantially as described.
4. In combination in a drill making machine, a frame supporting therein a blank
holding shaft, means for operating said shaft, a cutter head pivoted transversely to
the axis of the blank holding shaft, means for automatically swinging the cutter
head on its pivot, the cutter spindle borne in the cutter head to swing therewith,
the spindle driving shaft borne in a swinging frame and in engagement with the
cutter spindle, the swinging frame, and means for rotating the spindle driving shaft
simultaneously with the swinging movement of the cutter head, all' substantially as
described.
5. In combination in a drill making machine, a frame supporting therein a blank
holding shaft, means for operating said shaft, a cutter head pivoted transversely to
the axis of the blank holding shaft, means for automatically swinging the cutter
head on its pivot, the cutter spindle borne in the cutter head to swing therewith,
a cross shaft borne on the cutter head in operative engagement with the cutter
spindle, the spindle driving shaft borne in a swinging frame and in operative
engagement with the cross shaft on the cutter head, the yoke connecting the
spindle driving shaft and the shaft on the cutter head, the swinging frame, and
means for automatically driving the spindle driving shaft simultaneously with the
swinging movement of the cutter head, all substantially as described.
6. In combination in a drill making machine, a frame supporting therein a blank
holding shaft, means for operating said shaft, the cutter head supports, the cutter
heads pivoted in operative relation to the blank holding shaft and in the cutter
head supports, means for swinging the cutter heads on said pivots, the
cutter spindles borne in the cutter heads to swing therewith, the spindle
driving shafts in operative engagement with the cutter spindles, and means

page_text: or rotating the driving shafts simultaneously with the swinging movemen
he cutter heads, all substantially as described.
7. In combination with the swinging cutter head of a drill making machine, a
egmental gear borne on the head, a sectional shaft in operative engagement with
he segmental gear, the sections of the shaft turning together but having a sliding
movement one within the other, and means for rotating the sectional shaft, all
ubstantially as described.
8. In combination with the swinging cutter head of a drill making machine, a
lutch shaft, means for operatively connecting said clutch shaft and head, the
clutch devices borne on the shaft, means for engaging and disengaging said clutch
devices, and means for rotating said clutch shaft, all substantially as described.
9. In combination with the swinging cutter bead of a drill making machine, a
clutch shaft, means for operatively connecting said clutch shaft and head, the
clutch devices borne on the shaft and adapted to operatively engage the clutch
shaft, and means for automatically engaging and disengaging the clutch devices in
the operation of the machine, all substantially as described.
10. In combination with the swinging cutter heads of a drill making machine,
the segmental gears borne on the cutter heads, the sectional shafts in operative
engagement with the segmental gears, the clutches loosely mounted on the clutch
shaft and in operative engagement with the sectional shafts, the clutch sleeves
secured to the clutch shaft to rotate therewith but having a longitudinal movement
thereon and adapted to engage the clutches, means for moving said clutch sleeves
longitudinally on the clutch shaft, the clutch shaft, and means for rotating the
same, all substantially as described.
11. In combination with the swinging cutter heads of a drill making machine,
segmental gears borne on the cutter heads, the clutch shafts, the clutches loosely
mounted on the clutch shafts but adapted to be rotated therewith and connected
with the segmental gears, the equalizing shaft in engagement with said clutches,.
and means for rotating the clutch shaft, all substantially as described.
12. In combination with the swinging cutter heads of a drill making machine,
the segmental gears borne on the cutter heads, the sectional shafts in operative
engagement with the segmental gears, the clutches loosely mounted on the clutch
shaft and in operative engagement with the sectional shafts, the clutch sleeves
secured to the clutch shaft to rotate therewith but having a longitudinal movement
thereon and adapted to engage the clutches, incans for moving said clutch sleeves
longitudinally on the clutch shaft, the clutch shaft, the swinging bearings pivoted
to the clutch shaft, the equalizing shaft borne in the swinging bearings and in.
engagement with the clutch sleeves whereby simultaneous movement of the latter
and consequently of the cutter heads is secured, and means for rotating the clutch
shaft, all substantially as described.
13. In combination with the clutch shaft of a drill making machine, the clutches
loosely mounted thereon, the clutch sleeves secured to the clutch shaft to rotate
therewith but having longitudinal movement thereon, the releasing rods secured to
the clutch sleeves and to the slide, the slide, the slide operating rod in engagement
with the slide, and the clutch hand lever secured to the rod, all substantially as
described.
14. In combination with the clutch shaft of a drill making machine, the clutches
loosely mounted thereon, the clutch sleeves secured to the clutch shaft to rotate
therewith but having longitudinal movement thereon, the releasing rods in
engagement with the clutch sleeves, the links connecting the rods and slide, the
slide, and the slide operating rod in engagement with the slide and extending
through to the opposite side of the machine and provided with a hand lever, all
substantially as described.
15. In combination with the swinging cutter heads of a drill making machine,
5 the clutch shaft and means operatively connecting said shaft with said cutter heads
to swing them on their pivots, the clutch devices interposed between the clutch

page_text: shaft and the cutter heads, and means for automatically engaging and disengaging
said clutch devices in the operation of the machine, all substantially as described.
16. In combination with the clutch-shaft of a drill making machine, a clutch
loosely mounted on the shaft, a clutch sleeve secured to the shaft to rotate
therewith but having a free longitudinal movement thereon and adapted to engage
the clutch, the releasing rods in operative engagement with the clutch sleeve, the
operating rod in engagement with the releasing rods, mechanism for holding the
releasing rods at either limit of their play, and trip devices borne on moving parts
of the machine and adapted to engage and disengage the clutch devices, all
substantially as described.
17. In combination in a drill making machine, the swinging cutter heads, the
-clutch shaft and means operatively connecting said shaft with the cutter heads,
clutch devices borne on the clutch shaft and adapted to engage and disengage the
-cutter heads and clutch shaft, the clutch hand lever connected with the clutch
devices, the latch adapted to be engaged and disengaged from the hand lever, the
web yoke, the clutch disengaging rod adjustably secured to the yoke, and the
clutch engaging rod adjustably secured to the disengaging rod and adapted to trip
the latch and free it from engagement with the hand lever, all substantially
.as described.
18. In combination with a clutch shaft of a drill making machine, the clutch
-devices borne on the clutch shaft and adapted to engage and disengage said shaft
from operating parts of the machine, the releasing rods in engagement with the
clutch device, the clutch hand lever connected to the releasing rods, the latch
adapted to engage and disengage the hand lever, the web yoke, the clutch
-disengaging rod adjustably secured to the yoke, the engaging and disengaging yoke
adjustably secured to the disengaging rod, the engaging rod secured to the engaging
and disengaging yoke and provided with a trip adapted to engage the latch to
force it out of engagement with the hand lever, and means for rotating the clutch
shaft, all substantially as described.
19. In combination in a twist drill cutting machine, a movable blank holding
device, a cutter with its periphery supported in operative cutting relation to the
path of movement of a drill blank secured in the holder, and means for automatically
changing the angular relation of the plane of the cutter and the axis of the drill
blank, all substantially as described.
20. In combination in a twist drill cutting machine, a movable blank holding
device, a cutter with its periphery adjustably supported in operative cutting relation
to the path of movement of the drill blank, and means for automatically changing
the angular relation of the plane of the cutter and the axis of the drill blauk, all
-substantially as described.
Dated this Twenty-sixth day of April A.D. 1895.