Improved Drilling and Tapping Machine.
Year: 1897

page_text: Date of Application, 18th Dec., 1897
Complete Specification Left, 9th Sept., 1898-Accepted, 10th Dec., 1898
Improved Drilling and Tapping Machine.
We, GEORGE SONNENTHAL, Engineer, and HENRY BAMFORD, Engineer, both of
85, Queen Victoria Street, in the City and County of London, do hereby declare
the nature of this invention to be as follows:-
This invention relates to drilling and tapping machines either portable or
fixed, and has for its chief object to reverse the motion imparted to the drill
or tap spindle so that the tool is withdrawn more easily and quickly from the
work.
To carry out the invention an open frame or press of suitable configuration is
employed, in which frame is journalled a centrally located shaft which forms the
drill or tap spindle. Mounted upon the drill or tap spindle are two worm wheels
each rotated by a worm or endless screw, one of a left and the other a right
handed pitch, the endless screws being rotated by spur gear. The worm wheel
to withdraw the tap would preferably be made of a smaller diameter than the
other, so that a quick reverse movement is imparted to the drill or tap spindle
when withdrawing the drill or tap.
Between the two worms and upon the drill or tap spindle is arranged a suit-
able clutch mechanism controlled by a hand or other suitable lever fulcrummed
on the frame at or about the middle of its length, so that when one end is
depressed, the other is raised and vice versa.
The clutch is so arranged that when it is in one of its two positions the rotation
of one of the worms, will impart to the drill spindle a right hand motion, the
other worm being free to rotate on its journal. Upon reversing the clutch, the
former wheel is freed and the latter wheel rotates in a reverse direction, thus
reversing the tap by a more rapid movement.
In a modification of the tool we may employ a system of bevelled gear to drive
the drill or tap spindle.
Mounted upon the drill or tap spindle are two toothed crown or bevelled wheels,
the teeth in each facing inwards or towards each other so that they can be
simultaneously rotated by a toothed pinion placed between them, which forms
the driver, and imparts to the crown wheels a contrary motion.
Dated this 18th day of December 1897.

page_text: 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 drilling and tapping machines either portable or
fixed, and has for its chief object to reverse the motion imparted to the tap
spindle so that the tool is withdrawn more easily or quickly from the work.
To carry out the invention an open frame or press of suitable configuration is
employed, in which frame is journalled a centrally located shaft which forms the
drill or tap spindle. Mounted upon the drill or tap spindle are two worm wheels
each rotated by a worm or endless screw one of a left and the other of a right
handed pitch, the endless screws being rotated by spur gear. The worm wheel
to withdraw the tap would preferably be made of a smaller diameter than the
other, so that a quick reverse movement is imparted to the tap spindle when with-
drawing same.
Between the two worms and upon the drill or tap spindle is arranged a suit-
able clutch mechanism controlled by a hand or other suitable lever fulcrummed
on the frame at or about the middle of its length so that when one end is
depressed the other is raised and vice versa.
The clutch is so arranged that when it is in one of its two positions the rotation
of one of the worms will impart to the drill or tap spindle a right hand motion
the other worm being free to rotate on its journal. Upon reversing the clutch,
the former wheel is freed and the latter wheel rotates in a reverse direction thus
reversing the tap by a more rapid movement.
We will now describe the invention with reference to the accompanying draw-
ings in which :-
Fig. 1 shews a side elevation of one form of drilling machine constructed
according to our invention.
Fig. 2 shews a sectional end elevation of Fig. 1.
Referring to Figs. 1 and 2.
a is an open frame or press of the shape shewn, through one side of which, in
a suitable bearing, the driving shaft b penetrates. On the end of shaft b within
the frame is mounted a spur wheel the teeth of which engage with those of two
toothed pinions d, e, disposed one on either side of and receiving motion from,
the spur wheel c.
The pinion d is mounted upon the end of the shaft f of the endless screw g, the
rotation of which turns the worm wheel mounted loosely upon the central
vertical shaft i which forms the drill or tap spindle.
The pinione by a similar arrangement drives a second worm wheel h¹ also
mounted loosely upon the drill or tap spindle, by means of the shaft f¹ and end-
less screw g¹.
Between the two worm wheels is disposed the clutch j mounted on a feather
in the drill or tap spindle i, and capable of being raised or lowered to engage
either of the worm wheels h h thereby causing the drill or tap spindle to rotate
in either direction to advance or withdraw the tap. The clutch j is operated
by a lever fulcrummed on the frame at k¹. The inner end of the lever is
provided with a pin which engages a circumferential groove m formed on the
clutch j.
The top of the frame a is provided with a sleeve which receives and supports
the upper end of the drill or tap spindle. The worm wheel h is as shewn, of
smaller diameter than the wheel to ensure the rapid withdrawal of the tap.
When our invention is used as a drill, the drill spindle can be withdrawn by
unscrewing the hand wheel o¹, which slackens the screwed spindle o² inside the
sleeve o thereby permitting the removal of the drill.
When our invention is used for tapping, the tap is withdrawn by reversing
the motion imparted to the drill spindle, and the drilling bit holder o³ (part of
which is shewn), is slotted to allow of the up and down movement without it
being necessary to slacken the hand wheel o!.

page_text: Any suitable alternative arrangements to those above described may however
be used without departing from the principle of our invention.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
(1). The improved drilling and tapping machine, substantially as described
and shewn with reference to Figs. 1 and 2.
(2). In an improved drilling and tapping machine the reversible driving and
tap withdrawing mechanism consisting of two worm wheels hh', caused to rotate
in opposite directions by spur or other gear and a clutch constructed to slide
on a feather fixed to the drill or tap spindle i whereby either of the worm wheels
may be locked to the drill or tap spindle, substantially as shewn and described.
(3). In an improved drilling and tapping machine the combination of the
frame a spur wheels c d e shafts f f endless screws g g worm wheels h¹
mounted loosely on drill or tap spindle, clutch and means for operating said
clutch to drive the drill or tap spindle in the direction required, substantially as
described and shewn.
Dated this 9th day of September 1898
S. S. BROMHEAD,
Agent for Applicants, 171, Queen Victoria Street, London, E.C.