Improvements in Machines for Drilling and Tapping.
Year: 1889

page_text: Date of Application, 13th Aug., 1889-Accepted, 28th Sept., 1889
COMPLETE SPECIFICATION.
Improvements in Machines for Drilling and Tapping.
I, ULRICH EBERHARDT, 97 Congress Street, in 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 combine with a drilling machine means for making
a screw thread in a drilled hole, while the work is supported upon the table of such
drilling machine; and the invention consists in the combination with the spindle of a
drilling machine and the gearing for rotating the same, of a tap spindle sustained in a
head adjacent to the drill spindle, and provided with gearing for driving such tap
spindle in opposite directions.
By thus arranging a tap spindle adjacent to the drill spindle, and providing the tap
spindle with means for turning it in opposite directions, the work placed upon the
carrying table or platform beneath the drill may, when a hole is drilled, be readily
shifted beneath the tap, and a screw thread formed in the hole by applying the tap in
the usual manner.
The invention also consists in the combination and arrangement of specific parts,
as for coupling the tap spindle in certain cases to the drill spindle, for rendering the
operation of the drill spindle automatic, and other features hereinafter set forth and
claimed.
In
In the drawing, Fig. I is a side elevation of a column drill having the tap spindle
connected, therewith as an attachment; Fig. 2 is a front elevation of the same.
both these views many details of the tap spindle gearing are omitted, as they are fully
shown in the other figures.
Fig. 3 is a front view of the lower spindle bracket with the lower end of the
spindle and the tapping device secured by a foot to the spindle bracket; Fig. 4
is a side view of the same tapping device removed from the spindle bracket; Fig. 5 is
a view of the tap spindle shown in Fig. 3, with a portion of the bearings, and the
clutch block shown in its lowest position.
Figs. 3, 4 and 5, are drawn upon a much larger scale than Figs. 1 and 2.
Fig. 6 is a plan of the lower spindle bracket with the attached bearing for the tap
spindio, the view being taken in section on line a, a, in Fig. 1, and upon a slightly larger
scale; Fig. 7 is a plan of the work table and table arm detached from the column,
upon the same scale as Fig. 6. Fig. 8 is a side view of the gear e detached from
the bearing a Fig. 9 is a plan of the gib for holding the gear in the bearing;
and Fig. 10 is a plan of the gear d with its clutch rollers. Fig. 11 is a detached
view of the intermediate tap spindle gear. Fig. 12 is a section on line 9, 9, in
Fig. 5.
In Figs. 1 and 2, the drill spindle is shown driven by a cone and belt, and the
tap spindle is shown provided with gearing driven by a belt independently of the
drill spindle.
The drill spindle could thus be started and stopped at the pleasure of the operator
by a belt shifter or clutch, as is well understood. In these figures, A is the column of
the drill, with post B at the bottom to which is clamped the table arm B supporting
a rotary table C. The front of the column is provided with a dove-tailed guide A¹ to
which the lower spindle bracket D is movably fitted.
The top of the column is provided with a goose-neck A' having bearing E to
support one of the gears E' for driving the gear spindle F. A cone shaft F' is fitted
to bearings F above the goose-neck and provided with cone F³ driven by belt F*,
as usual.
A sleeve H is shown fitted movably to a bearing D' upon the bracket D. and

page_text: the spindle is shown fitted into such sleeve and adapted to move vertically therewith
by means of the drill socket G at the lower end of the sleeve H and collar G¹ at the
top of the sleeve H.
Such sleeve is actuated, as shown in Fig. 6, by a pinion D2 applied to a rack upon
the sleeve and by a hand wheel H connected with the pinion by a shaft having a
bearing upon the bracket.
By turning the wheel H³, the drill D³ (shown in Fig. 2) is moved to and from the
work table while the bracket may be adjusted vertically upon the column to increase
the range of the spindle, as is already well known.
a is the tap spindle sustained in bearings a¹ and a² formed upon a frame b
provided with a foot .
The foot is fitted to a seat c upon the side of the bracket D, and is provided with
slotted holes c through which bolts are inserted to clamp it to the bracket.
Gears d
and e are fitted loosely to the tap spindle, and are driven in opposite directions by
gears and e¹ upon an auxiliary shaft y, which is shown in Figs. 1 and 2 extended
upward to connect with a cone shaft h by means of gears h¹.
An intermediate gear e² connects the gears ennil et, to reverse the motion of the
gear wheel e.
The shaft and the upper end of the shaft g, are sustained in
bearings attached to the goose-neck A2. The shaft g is splined above the bearing a²
to slip through the gear so as to slip through the same when the bracket is
adjusted vertically, and cone is driven by an independent belt h³.
The means
for connecting the clutch block with the gears d and e, is shown in the other figures,
but it is evident that by coupling the tap spindle successively to the gears d and
may be rotated in opposite directions as is required for operating the tap t.
e,
Any piece of work laid upon the table may therefore be readily drilled, by
using the drill D³ in the usual manner. The drill being retracted the work can
be shifted beneath the tap t, and by actuating the tap spindle and the clutching
mechanism in a suitable manner, the tap be inserted in the hole and removed there-
from to form a screw thread therein.
In radial drills where the arm carrying the spindle is movable, it is common to use
a stationary work supporting table, upon which the work could be shifted as readily
as upon the movable table shown herein; but it is obvious that if the table be
movable, with the arm B around the post or column of the drill, it would be
necessary to arrange the tap spindle at the same distance as the drill spindle from
the center of the column, so that any piece of work fastened to the table might be
shifted from the drill to the tap without loosening the work from the table.
Such an arrangement is shown in Fig. 6, where the centers of the drill spindle F
and the tap spindle a are shown arranged upon the dotted line y, y, concentric with
the center of the post B.
In Fig. 7, the relation of the table to the two spindles is clearly shown, the center
of the table being shown upon a curve =,, extended through the centers of the drill
and tap spindles, concentric with the post B. In Figs. 3, 4 and 5, means is shown for
actuating the clutching devices by hand and also automatically, and for connecting
the tap spindle, by detachable gearing with the drill spindle, so that the movement of
the drill spindle downward in operating the drill, would serve to disengage the tap
spindle therefrom and thus arrest its rotations, while the retraction of the drill from
the work, and the elevation of the drill spindle sleeve to its highest point in the
sleeve bearing D₁, would couple the tap spindle to the sleeve spindle, and thus
rotate the tap spindle to operate upon the same piece of work.
By this construction, the rotations of the tap spindle aro automatically arrested
during the use of the drill, and may be renewed as soon as the drill is retracted;
such construction entirely obviating the need of a separate driving belt for the
tap spindle, as shown in Fig. 2.
The detachable gearing consists in a cog-wheel p attached to the shaft y adjacent to
the lower end of the drill spindle sleeve bearing D¹, and a cog-wheel p' shown
secured to the spindle by fastening it upon the drill socket G adjacent to the
lower end of the sleeve H.

page_text: In Fig. 3, the two cog-wheels are shown meshed together by the
leeve H to its highest point, so that the rotation of the drill spindle would impart
he desired movement to the wheel d or e, and thus actuate the tap spindle reversably,
s desired. In the same figure, the drill socket G and the wheel p are shown in
lotted lines moved downward, with the drill (also shown in dotted lines) represented
nserted in a piece of work t'.
Such downward movement of the spindle would obviously detach the wheel p' from
he wheel p, and thus automatically arrest the movements of the tapping device during
he drilling operation, while the lifting of the drill from the work for the. purpose of
ringing the drilled hole to the tap t, would automatically engage the cog-wheels p
and p', and thus rotate the gearing of the tap spindle.
The tap spindle a is provided with a grooved collar n fixed thereto by a set screw
(when properly adjusted), and may be moved up or down by a tap lever n having
weight n to normally lift the spindle, and a handle n³ to press the spindle down for
starting the tap, in opposition to the weight n
The clutch block fand the wheel e are provided with clutch teeth to reverse the
tap at a quick speed, and the opposite end of the clutch block and the adjacent gear
wheel d are provided with rollers d' and f, which are designed to engage past their
respective centers for rotating the tap spindle, in tapping the drilled hole; and to
facilitate the withdrawal of the clutch block from the gear automatically. When
teeth are used upon the clutch members, the friction induced upon their opposed faces
in screwing the tap into the drilled hole offers a very great resistance to their separa-
tion; whereas the rollers move apart with great facility.
The rolls are shown fitted to radial studs projected from opposite sides of the
clutch block close to its lower end, and the rolls d' are shown fitted upon radial pivots
in bearings fitted within a recess d in the upper side of the gear wheel d. The
rotation of the wheel d, when the rollers are engaged past their line of centers, as
shown in Fig. 5, thus operates to turn the clutch block, which is fitted, by feathers f²,
to slide upon the tap spindle, so as to rotate the latter while the spindle moves freely
through it.
To reverse the tap spindle automatically when the tap has penetrated the drilled
hole the desired depth, a depth collar m¹ is fitted loosely to the spindle above the
bearing a², and coupled to the movable end of a lever m²; pivoted like the lever n¹,
upon a seat m² on the frame b.
A hand lever o for moving the clutch block downward to start the lap, is shown
attached to the seat by a fulcrum o', the hand lever being pivoted to the clutch
block in front of the fulcrum by pins o, and in the rear of the fulcrum to a link m
connected with the lever m³.
The link being pivoted to the lever m' and the hand lever os apon opposite sides of
their fulcra, the downward movement of the depth collar m² operates to raise the
clutch block, and to thus detach the rollers and .
When thus detached, means is necessary to shift the clutch block upward to engage
the teeth e, and such means is provided in a spring bolt I pressed toward a beveled or
inclined seat o upon the end of the lever o³.
When the corner of the bolt engages with the outer corner of the inclined seat, the
end of the lever is therefore moved laterally by the pressure of the bolt.
A spring, inserted in a suitable socket behind the bolt, operates to press it
normally forward, and the downward movement of the clutch block operates to thrust
the spring bolt backward.
The operation of the entire mechanism is as follows; the operator depresses the
drill spindle to drill the hole which he desires to tap, and thereby disengages the
gears p and pl.
When the drill is lifted from the finished hole, the gears p and pl are then engaged,
and the gear wheels d and e rotated to actuate the tap.
The work having the drilled hole is then shifted beneath the tap by turning the
table C around upon the post B, or by shifting the work upon the supporting table.

page_text: Ine hand lever of is then depressed which engages the rollers d' and f¹ past thei
respective centers.
The strain transmitted to the rollers" operates, by the interlocking of the opposed
rollers past their respective centers (as shown in Fig. 5) to hold the clutch block
downward, and to prevent the rolls from slipping away from one another.
The tap is thus rotated in the proper direction to enter the drilled hole.
The collar being fixed upon the spindle at a suitable distance from the depth
collar m. presses upon the latter when the tap has penetrated nearly to the desired
depth, and thus forces the lever m², link m, and the rear end of the levor o downward.
The continued movement of the tap, in the drilled hole, presses the depth-collar
downward until the clutch block is raised with the centers of the rolls f¹ above the
centers of the rollers d'.
The rolling surfaces, in contact with one another, then produce a strong tendency
to lift tho rolls f', and thus wholly disengage the clutch block from the gear
wheel d.
The incline o upon the rear end of the hand lever then reaches a point where the
spring bolt presses upon the incline o, which forces the rear end of the hand lever
still farther downward, and throws the clutch block upward to engage the teeth e, as
shown in Fig. 4.
The continued pressure of the bolt upon the incline o then serves to hold such
teeth in contact, until the operator presses the clutch block downward.
The engagement of such teeth rotates the clutch block and the tap spindle in the
opposite direction, thus retracting the tap from the hole, as desired.
When the tap is entirely clear of the hole, the weight, n operates to overbalance
the weight of the tap spindle, and lifts the tap clear of the work so that the latter
may be removed. The collar n is made adjustable upon the tap spindle to regulate
its automatic operation in reversing the tap, in drilling holes of various depths and
by making allowance for the slight movement of the depth collar in separating the
rolls and, a scale may be used upon the tap spindle, to set the collar n at the
desired point. Such scale is shown at a, in a series of marks numbered in inches to
express the proper setting of the collar for a hole of corresponding depth.
Where it is necessary to use a drilling machine for a considerable time without
actuating the tap spindle, the gears p and pl may be separated from one another
by a backward movement of the frame & carrying the entire tapping apparatus.
Such backward movement is effected by slackening the bolts applied to the slotted
holes t', and shifting the frame backward upon the drill spindle bracket D. The
slcove may then be moved upward to its normal height without engaging the
gears p and pl
When it is desired to use the tapping apparatus, it may be connected with the drill
spindle by again shifting the frame forward.
proper operation of the tap spindle in opposite directions, whether the clutch block be
It is obviously immaterial to the
provided with teeth at its upper end and rollers at its lower end, or the contrary;
but, by my construction, the weight of the clutch block, and the hand lever attached
thereto, operates to hold the rollers engaged past their respective centers during the
tapping operation until lifted by the operation of the depth-collar acting through 4
suitable connections.
I am aware that it is not new to mount a drill spindle and tap spindle upon the
same frame over a stationary table, and to drive the same by independent belts, and
I do not therefore claim such device broadly as my invention. My construction
differs from that referred to, partly, in having gearing which is connected with the 5
gearing for driving the drill spindle in a single direction, and also with the gearing
for driving the tap spindle in opposite directions; and partly, in the combination,
with the drill and tap spindle, of a movable table adapted to shift the work when
fastened upon the same, directly from under the drill to a corresponding point under
the tap, without loosening the work from the table. By my first construction I am 5
enabled to apply a tapping device to any existing drilling machine, by providing the

page_text: suitable intermediate gearing to connect the gearing of the drill with the gearing of
the tap; and by my second construction, I am enabled to hold the work more securely
upon the table by drilling and tapping it than if the work were laid loosely upon the
fixed table, and shifted from one tool to the other when required.
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. The combination, with the spindle of a drilling machine and the gearing for
rotating the same, of a tap spindle mounted in a head sustained adjacent to the drill
spindle, gearing for driving such tap spindle in opposite directions, and gearing
connected with the same and with the gearing of the drill spindle, and a movable
table for applying the work in succession to the drill and tap, substantially as herein
set forth.
2nd. The combination, with the spindle of a drilling machine and the gearing for
rotating the same, of a tap spindle mounted in a head sustained adjacent to the drill
spindle, gearing for driving such tap spindle in opposite directions, and gearing connected
detachably with the same and with the gearing of the drill spindle, and a movable
table for applying the work in succession to the drill and tap, substantially as herein
set forth.
3rd. The combination, with a column drill, of a table, a table arm supporting the
same and movable around the column, a drill spindle and tap spindle sustained by
the column of the drill, gearing for driving the drill spindle to drill holes, gearing for
driving the tap spindle in opposite directions, and gearing connected with the same
and with the gearing of the drill spindle, substantially as herein set forth.
4th. The combination, with the spindle of a drilling machine and the gearing for
rotating the same, of a tap spindle, a lica affixed to the lower drill spindle bracket,
gearing to reverse the tap spindle, a toothed coupling wheel inserted in such gearing
adjacent to the lower side of the drill spindle bracket, and a cog-wheel fixed upon the
drill spindle and movable therewith to mesh at pleasure, with the coupling wheel, as
and for the purpose set forth.
5th. The combination, with a column drill having a table and a table arm movable
around the column, and having a drill spindle bracket adapted to sustain the drill
concentric with the table, of a tap spindle head sustained adjacent to the drill spindle,
and adapted to sustain the tap spindle concentric with the table when the latter is
moved around the column, and gearing for reversing the tap spindle, as and for the
purpose set forth.
6th. The combination, with a tap spindle and suitable bearings for sustaining the
same, of two gear wheels fitted loosely upon the spindle and rotated in opposite
directions, a clutch block feathered upon the spindle and movable between the gear
wheels, teeth upon the clutch block and upon one of the gear wheels for driving the
spindle in one direction, and rollers affixed to the clutch block and the other gear
wheel, and adapted to be moved into contact with one another past their respective
conters for driving the spindle in the opposite direction, substantially as herein
set forth.
7th. The combination, with a tap spindle and suitable bearings for sustaining the
same, of two gear wheels fitted loosely upon the spindle and rotated in opposite
directions, a clutch block feathered upon the spindle and movable between the gear
wheels, teeth upon the clutch block and upon one of the gear wheels for driving the
spindle in one direction, rollers affixed to the clutch block and the other gear wheel.
and adapted to engage past their respective centers for driving the spindle in the
opposite direction, a lever having a fixed fulcrum and pivoted at one side of the
fulcrum to the clutch block, and provided at the other side of the fulcrum with a
sloping face, a spring dog adapted to press the lever laterally when engaged with
such face, and a handle applied to the lever for shifting the clutch block toward
either of the gear wheels, substantially as herein set forth.
8th. The combination, with a tap spindle and suitable bearings for sustaining the

page_text: saine, of two gear wheels fitted loosely upon the spindle and rotated in opposite
directions, a clutch block feathered upon the spindle and movable between the gear
wheels, teeth upon the clutch block and upon one of the gear wheels for driving
the spindle in one direction, rollers affixed to the clutch block and the other gear
wheel, and adapted to engage past their respective centers for driving the spindle in
the opposite direction, a lever having a fixed fulcrum, and pivoted at one side of the
fulcrum to the clutch block, and provided with a handle, the link m pivoted to the
lever at the opposite side of the fulcrum, the depth-collar m¹, the arm m² pivoted to
the link and actuated by such collar, the collar'n fixed upon the spindle above the
depth-collar m, and adapted when moved downward into contact with the latter to
raise the clutch block into contact with the reversing gear wheel, substantially as
herein set forth.
9th. The combination, with a tap spindle and suitable bearings for sustaining the
same, of two gear wheels fitted loosely upon the spindle and rotated in opposite
directions, a clutch block feathered upon the spindle and movable between the gear
wheels, teeth upon the clutch block and upon one of the gear wheels for driving the
spindle in one direction, rollers affixed to the clutch block and the other gear wheel,
and adapted to engage past their respective centers for driving the spindle in the
opposite direction, a lever having a fixed fulcrum, and pivoted at one side of the
fulerum to the clutch block, and provided with a handle, the link m pivoted to
the lever at the opposite side of the fulcrum, the collar m¹, the arm m² pivoted to
the link and actuated by such collar, the collar » fixed upon the spindle, the tap
lever actuated by such fixed collar, the weight n for moving the lever to normally
raise the spindle, and the handle a³ for pressing the spindle downward, as and for
the purpose set forth.
10th. The combination, with the spindle of a drilling machine and the gearing for
rotating the same, of a tap spindle mounted in a movable frame adjacent to the drill
spindle, and gearing for driving such tap spindle in opposite directions, connected
with the gearing of the drill spindle, the movable frame being adapted by its
movement to detach the gearing of the tap spindle from the gearing of the drill
spindlo, as and for the purposo set forth.
11th. The combination, with a tap spindle and suitable bearings for sustaining the
same, of two gear wheels fitted loosely upon the spindle and rotated in opposite
directions, a clutch block feathered upon the spindle and movable between the gear
wheels, and adapted to engage with either of such gear wheels, a depth-collar fitted
loosely to the tap spindle above its bearings and connected by a link and suitable levers
with the clutch block to raise the same by the depression of the depth-collar, an adjustable
collar fixed upon the tap spindle to press upon the depth-collar, and a scale upon the
tap spindle for setting th adjustable collar, as and for the purpose set forth.
'
Datod thie 12th day of Avec 1889
HERBERT J. ALLISON,
Agent for the Applicant.