Improvements in Automatic Drilling Machines.
Year: 1887

page_text: Date of Application, 12th July, 1887.
Specification Accepted, 23rd Sept., 1887.
Improvements in Automatic Drilling Machines.
I, ULRICH EBERHARDT, of the city of Newark, county of Essex, and state of
New Jersey, United States of America, Machinist, 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 this invention is to improve the construction of a drilling machine in
respect to its feeding mechanism, the means for operating the back gearing and in
other details of construction hereinafter described and claimed.
In the drawings, Fig. 1 is a side elevation of the entire machine.
Fig. 2 is a detached view of the top of the frame, with the shaft-bearings in section
on line y, y, in Fig. 3. Fig. 3 is a plan of the top part of the machine, with the cone
and its attachments removed by a section on line a, a, in Fig. 2, and the bevel gears
which are shown in Fig. 2 omitted.
Fig. 4 is a section of the friction disk and wheel, on an enlarged scale, on line z, z,
in Fig. 3.
Fig. 5 is an elevation of the upper shaft bearings, taken on line v, v, in Fig. 2.
Fig. 6 is a front elevation of the machine. Fig. 7 is a rear elevation showing the
various helt connections. Fig. 8 is a section of the clutch-cone on line w, w, in Fig. 2.
Fig. 9 is a plan of the sliding sleeve and its hearing in the movable bracket; Fig. 10
a vertical section of the drill-spindle socket on line r, r, in Fig. 1, and Fig. 11 a
similar section at right angles to the last.
My improvements are especially adapted to vary the speed of the tool more readily
both in respect to its rotations and the rate of its feed, by which means the time
heretofore lost in operating similar drilling machines, is avoided, and the operator is
enabled to avoid such a speed for the drill that the cutting edge would be destroyed
by too quick a rate, or time be lost in operating on the material by too slow a rate.
I have frequently found that with a slow back-gear speed a feed of only one sixty-
fourth of an inch was attainable for each revolution of the tool, while one-sixteenth to
one eighth of an inch feed is frequently required in feeding a reamer of a large size.
The feeding devices heretofore used are thus not only too limited in their range, but
cannot be operated when the machine is in motion without danger and inconvenience
to the operator.
I overcome these defects in the feeding devices, first, by the use of a frictional

page_text: driving disk from which a finely-varied range of speeds may be derived; secondly, by
driving such disk from the counter shaft of the machine wherever located, the speed of
which is not affected by the back-gear connections or by the shifting of the cone-belt;
and, thirdly, by providing a shifting attachment for the friction wheel, which attachment
can be operated while the machine is in motion, and which I mark with suitable
figures, and provide with a gage, so that the operator may set the feed directly at the
proper speed for a drill of given size.
I also connect the friction driving disk with the counter-shaft by means of cone-
pulleys fitted to revolve the disk at different speeds for materials of different hardness,
as cast and wrought iron.
Heretofore in standard drills, the back-gearing has been located upon the top of the
drill where it was almost inaccessible.
In my present construction I obviate this defect by providing a lever accessible to
the operator when standing upon the floor, and extended to and connected with the
back-gear shaft and with a clutch combined with the upper cone, thus securing a means
for unclutching the cone and engaging the back-gear by a single movement.
The spindle sle ve within which the spindle revolves, and which is commonly
mounted upon a bracket, so as to hold and feed the spindle close to the tool socket, has
generally heretofore been made of cylindrical form, and had a toothed rack attached to
it by means of screws to receive the feeding motion from a rotary pinion.
Such a round sleeve is difficult to clamp firmly when it begins to wear, and the
screws of the feeding rack frequently get loose, so that the feeding movement and
guiding of the drill both become defective.
In my construction I make the sleeve of rectangular shape, and form the toothed
feeding rack integral therewith, by which means I prevent the rack from ever getting
loose and secure a form for the socket, wherein the sleeve is mounted, by which I can
readily clamp the same and compensate for any wear upon its front side.
Heretofore a flat transverse slot has been formed across the upper end of the socket
in the drill-spindle to engage the flattened ends of the tool-shanks applied to the
socket; but such slot is constantly worn by the end of the shank, and is often greatly
damaged by the tapering drifts which have been forced into the slot to drive the shank
out of the socket, and I have therefore devised a means of forming a slot in a detach-
able steel piece which can be readily removed, and which is also adapted to drive the
tool-shank from the socket without the use of any drift or wedge.
The nature of my improvements will be understood by reference to the annexed
drawings, in which A is the column of the machine, and B the frame attached thereto
to support the counter-shaft C, cone-shaft D, back-gear shaft E, and disk shaft G.
C are the bearings of the counter-shaft, supporting the same upon the lower part of
the frame, and the lower driving-cone; D¹, D², the bearings of the cone-shaft,
supporting the same at the top of the machine, and 13 the upper driving-cone; E1, E2,
the bearings of the back-gear shaft arranged just below the cone-shaft, and G', G³, are
the bearings of the disk shaft attached to one side of the frame and column adjacent
to the back-gear shaft.
F is the spindle, fitted with a spline s, to a bevel gear S, which is sustained
in a bearing F, at the top of the frame, and is held at its lower end in a sleeve H,
which is formed to fit a rectangular split bearing H2 upon a bracket K movably held
upon a dovetail K¹, upon the front of the column, as in other machines.
S¹ is a bevel gear on the cone-shaft D, and fitted to the gear S, and the power is
thus transmitted from the cone-shaft to the drill spindle as the latter moves up
and down through the gear S.
'
H' is a toothed rack formed integrally upon the inner side of the sleeve, and I, I',
the worm gearing usually employed to reduce the quick movement of the drill feeding
shaft to the proper speed for the pinion a, which operates the rack H¹ (see Fig. 9).
J is the drill feeding shaft, fitted to bearing b upon the bracket K, and to
bearings c, c', attached to the front bearing G¹, of the disk-shaft, and provided with a
frictional driving wheel e splined to the shaft J, as shown at e' in Fig. 4.
Jare shifters attached to a hand rod J', which is fitted to lugs C2 upon the

page_text: bearings c, c', the shifters being arranged to move and hold the wheel e in contact
with the frictional disk d at any desired point.
The rod J is furnished with a handle J³ for moving it, and is clamped in the
desired spot by means of a hand screw e inserted in one of the bearings c', which
is split open to allow its opposite sides to yield.
The disk d is shown recessed at the center in Fig. 4, to afford a spot where the
wheel e can be placed at rest while the disk is revolving, and by means of the rod J³
the friction wheel e can be moved to such central point to stop the feed entirely, and
can be moved from thence in either direction up or down to feed the drill spindle
either upward or downward at an increasing rate of speed proportioned to the distance
of the wheel e from the center of the disk.
The rod J is shown in Fig. 6 marked with a series of marks i, and with
figures,, 1, 1, and the edge of the lower bearing c² serves as a gage, with which
any mark is set in contact to secure a speed suitable for a drill of the size marked
thereat.
The disk shaft G is provided with two cone speeds 9, 9', and similar cone speeds f,f,
are provided upon the counter shaft C, and a belt L, Fig. 7, serves to convey either a
quicker or a slower speed to the disk shaft, as may be suited to the material operated
upon.
The variation of speed produced by the use of the cones g, g¹, is intended to
be just that which is required in shifting from cast to wrought iron, and the series of
marks on the rod J' are therefore equally applicable, whichever metal the tool be used
upon.
To obtain a longer traverse for the feed when operating a boring bar by the
spindle F, I affix a screw F¹ to a bearing F upon the bracket K, and fit the thread of
the screw which extends upward along the column A, to a nut F3 affixed to such
column; and connect the screw by bevel gears F with the worm gearing I.
Such connection is made detachable by mounting one of the gears F4 with its hub,
in a bearing F upon the bracket K, and forming the hub of the gear and the hub of
the wheel each with a square socket & into which a sliding key is inserted when
the connection is desired, as shown in Fig. 1°.
In practice, the worin wheel I¹ is connected with its shaft by a friction clamp and
may therefore be detached when desired; and when thus detached the rotations of the
worm wheel I would be transmitted only to the screw F, F, to move the bracket
bodily up and down upon the slide K₁ instead of operating the tooth rack H in
its bearing to produce the feed.
In Fig. 1, M is a stationary bar formed upon the frame B adjacent to the lower
cone C, and provided with marks adjacent to each of the cone speeds or pulleys
to guide the operator in applying the belt to the cone for a drill or tool of given size.
The cone speeds are shown as four in number, and in the drawings are proportioned
to furnish the required variation in speed between drills of three eighths of an inch
and one and one quarter of an inch in diameter without the use of the back-gearing..
Thus the quickest speed is adapted for the three eighths and one half inch drills,
and the figures and are accordingly marked upon the stationary bar M, adjacent
to the largest cone speed, each other speed having two other figures marked near it,
as the same speed may be very readily used for drills of but one eighth inch variation
in size. Similar figures may be marked upon the rod J2, or each alternate figure,
if the space be cramped, as shown in Fig. 6, and the operator is then enabled
to immediately secure the proper speeds both for the driving and the feeding of
a drill of given size.
It is obvious that in addition to or in place of the drill-sizes the index M may
be marked with the actual speeds, and the rod J2 may be marked with the actual feed
produced for each revolution of the spindle when the latter is actuated by the same
cone speed without the intervention of the back-gear. Such a series of indications is
shown upon the plate M in the numbers 40, 60, 100, 160.
Upon the back-gear shaft E are secured a large gear m, and small gear m¹, and a
small gear n is attached to the hub of the cone D to rotate the back-gear shaft when

page_text: t
the gears are meshed together. A large gear n¹ is attached to the cone shaft D,
adjacent to the gear n, and the gears m, m³, are so arranged upon the shaft E that
when the latter is shifted end wise, as shown in Fig. 3, the two gears on the shaft E
mesh into the gears n, n', and the quick motion of the cone is transmitted to
the shaft D in a reduced ratio.
When the back-gears are disconnected, as shown in Fig. 2, the cone D' would slip
around upon the shaft, and to connect the same with the shaft and avoid the use of
the hand locking devices heretofore employed I form clutch-teeth u, Fig. 8, upon the
hub of the cone, and apply a sliding clutch hub l, formed with similar teeth to the
rear end of the shaft I), so as to slide to and from the teeth u in the cone.
Pins and holes may be used instead of the teeth u.
The hub is fitted to a bearing D₁, at the rear end of the cone, and a link is
swiveled to the outer end of the clutch hub and connected with a hand lever P,
which is pivoted upon the frame B at p, and extended downward within reach of the
operator when standing upon the same level as the base A¹, which sustains the
column A.
The pivot pis arranged between the shafts D and E, and a link is swiveled to
the outer end of the back-gear shaft E, so that the movement of the lever serves to
draw the back-gears m, m³, n, n', out of mesh with one another at the same time that
the clutch is pressed into the cone and the latter locked to the shaft D.
The hub is splined to the shaft, as at o in Fig. 2, and therefore drives the shaft
at the same speed as the cone D³ when thus clutched thereto, while an opposite
movement of the lever serves to unclutch the cone from its shaft and to engage the
back-gearing together, so as to rotate the shaft D at a slower speed.
The links and are loosely pivoted to the lever at 1³, 13, and are swiveled to the
parts and E by caps t, attached to the ends of the shafts and inclosing-collars
formed upon the inner ends of the links. The links are thus adapted to slide the
parts and E in and out in their bearings while the latter are in motion, if the
operator desires.
If the pair of back-gears m, m³, and n, n', were each proportioned three to one,
the effect of using the same would be to reduce the speed of the cone shaft and drill
spindle in the ratio of nine to one; and if the feed were driven, as in other drilling
machines, by a belt or other direct connection with the cone shaft, the speed of the
feed would be reduced in the same proportion; but when the feed is driven indepen-.
dently of the cone-shaft, as in my construction, the effect of using the back-gear is
to actually reverse the speed of the feed in relation to the spindle speed.
Thus in the machines heretofore used, if the spindle be rotated by the cone at
ninety revolutions per minute with a feed of one thirtieth of an inch to each
revolution, the aggregate feed would be three inches in each minute; but when the
back-gear is used, with the cone still rotated at ninety turns per minute, the speed
of the drill and the feed are both reduced, the rotations to ten per minute, and the
feed to three ninths of an inch per minute, instead of three inches.
On the contrary, with my independent feed connections, if the spindle be rotated
ten revolutions per minute by throwing in the back-gear, the feed would still be
three inches in each minute, and would be actually increased in relation to each
rotation of the drill, and would become one third of an inch for each drill revolution,
instead of one thirtieth, as when the cone was used, the adjustment of all the cone-
feed speeds being unchanged and the back-gear alone being altered in the cases
just assumed.
An extraordinary and unusual advantage thus results from actuating the feed
mechanism by some uniformly-operating device not affected by the changes in the
spindle speed; and as it is immaterial whether the feed be driven by a belt from the
countershaft on the frame of the machine, or from some other uniformly rotating
shaft adjacent thereto, I do not limit myself exclusively to the means shown herein
for thus driving it.
A belt from the cone shaft D to the feed shaft G, such as has heretofore been used,
is obviously very short and constantly liable to get slack and to slip.

page_text: This defect has long been known in power drilling machines, and my construction
secures a great advantage in dissolving the belt connection between these shafts, and
driving the feed shaft by a belt from some remoter point, as the shaft C.
To press the disk d into suitable contact with the wheel e, a screw d' is mounted in
a split bearing d* behind the outer end of the disk shaft G, and the shaft can thus
be pressed end wise to any desired distance and the screw clamped in the bearing d²
by a bolt d³, applied to the opposite parts of the same.
Figs. 10 and 11 illustrate the means for preventing the wear in the drill socket
and for driving the drill out of the socket.
The improvement consists in a grooved plug inserted movably in a hole j across
the bottom of the socket F, the groove h¹ being shaped transversely to fit the flattened
end of the drill shank, and the bottom of the groove being inclined to the axis of the
hole, so as to operate as a wedge, and thus force the drill out of the socket when
moved end wise in the hole..
Such shifting may be readily effected by striking the plug upon the end with any
convenient object without any damage to the plug, as the same, being made separate
from the drill socket, can be formed of steel and hardened, so as to endure the blows
to which it would be subjected in use.
If the bottom of the groove were inclined in but one direction, the plug would
require to be driven always in the same direction to discharge the drill; and to avoid
the necessity of turning the drill shaft to reach the proper end of the plug, the
groove in Fig. 10 is shown with a concave bottom longitudinally, and may be
readily formed of that shape by a rotary milling-cutter.
With such a construction the groove operates in the same manner to discharge the
shank when driving through the hole j from either end.
It is obvious that a prismatic plug of any section would operate the same as the
round one shown herein, although the round form is the most convenient to produce
in practice.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1st. In a standard drilling machine, having the bracket K movable upon the
column A as set forth, the combination, with the bracket, of the spindle F, the sleeve H
and feeding mechanism for propelling the sleeve, the screw F1 journaled upon the
bracket K and fitted to a nut upon the column, and a detachable connection with the
feeding mechanism which operates the sleeve H, the whole arranged and operated
substantially as set forth.
2nd. In a standard drilling machine, having the drill feeding shaft driven by a
frictional wheel, and having the cone shaft driven by a counter-shaft C, with the
cone C³, as described, the combination, with the drill feeding shaft having the
frictional wheel secured thereon, of a frictional disk mounted upon a shaft driven by
a belt from the said countershaft, and means for shifting the frictional wheel in
contact with the disk, substantially as shown and described.
3rd. In a standard drilling machine having 'the cone shaft driven by a counter-
shaft, the combination, with the drill feeding shaft, of a frictional driving wheel and
disk, an independent shaft for carrying said disk, speed cones applied to the said disk
shaft and countershaft, and a belt to drive the disk shaft from the countershaft C, the
cones operating to vary the effect of the belt for drilling wrought or cast iron, sub-
stantially as shown and described.
4th. In a standard drilling machine provided with a frictional feed wheel, the
combination, with the shifters for shifting the wheel e, of the rod J' attached to the
said shifters, and provided with the figures for indicating the proper setting of
the wheel, substantially as shown and described.
5th. In a standard drilling machine, the combination, with a drill spindle having a
central socket for the shank of the tool and provided with a transverse hole at the
bottom of the socket, of the grooved plug, constructed as described and inserted

page_text: movably in said hole, and adapted both to rotate the tool and to force it out of its
socket, when required, substantially as shown and described.
6th. In a standard drilling machine, the combination, with the drill spindle F and
the split bearing H2, surrounding the same, of the rectangular sleeve H, having the
rack teeth H¹, formed integral therewith, for transmitting the feed movement to the
sleeve, substantially as herein shown and described.
7th. In a standard drilling machine, the drill frame A B, provided with the counter-
shaft C and cone C² arranged substantially as described, and the stationary bar M
arranged adjacent to the several belt faces upon the cone, and provided with figures
opposite the several faces of the cone to indicate the corresponding sizes of the drills
which should be used with the belt applied thereto.
8th. In a standard drilling machine, the combination, with the cone shaft D having
the gear n² secured thereto, and the cone D³ fitted loosely thereon, provided with the
gear, of the clutch having the hub 7 fitted to the end of the shaft D, the back-gears
mounted upon the back-gear shaft E parallel with the cone shaft D, as described, and
the lever P provided with the links and arranged to shift the clutch in one
direction and the back-gearing shaft in the opposite direction, substantially as and for
the purpose set forth.
9th. In a standard drilling machine, the combination, with a drilling machine
spindle, of a cone shaft geared thereto, a cone running loosely thereon, and back-
gearing adapted to drive the cone shaft when desired, a feeding mechanism for
moving the spindle longitudinally, and means for driving the feeding mechanism
independently of the cone shaft, and thereby reversing the relation of the feed to
the rotations of the drill when operated by the back-gear.
10th. In a standard drilling machine, the combination, with the bracket K movable
upon the column A as set forth, and having the sleeve H carrying the spindle F
movable in said bracket, the combination, with the column, the bracket, and the said
sleeve, of feeding mechanism operated substantially as described to move the bracket
upon the column, or to move the sleeve in the bracket at the pleasure of the operator,
as and for the purpose set forth.
11th. In a standard drilling machine, having the spindle sustained by a sleeve H
movable in a bracket K which is also movable upon the column of the drilling machine,
the combination, with the said parts and with the spindle driving apparatus, of a
frictional feeding device connected with the bracket and also with the spindle sleeve,
and mechanism substantially as described, for causing the frictional feeding devices
to move the bracket upon the column or the sleeve within the bracket at the pleasure
of the operator.
11- ນາມ
CTI
1007