Improved Apparatus for Tapping Metals.
Year: 1889

page_text: Date of Application, 28th Mar., 1889
Complete Specification Left, 27th Dec., 1889-Accepted, 1st Feb., 1890
PROVISIONAL SPECIFICATION.
Improved Apparatus for Tapping Metals.
I, JOHN MILEY, of South View, Highfield Lane, Keighley, in the County of
Lancaster, foreman draughtsman, do hereby declare the nature of this invention to be
as follows:-
My invention relates to the tapping of holes with screw taps and consists in an
improved portable apparatus for tapping holes by means of a drilling machine spindle
or other revolving spindle to which the apparatus can be attached.
The apparatus consists of a square box casting or case hereinafter called case jointed
at the centre and enclosing five bevil wheels, all of which have turned bosses at their
backs revolving in bearings arranged in the sides of the case. One of the wheel
bosses has a shank formed or attached to it which fits into the nose of a drilling
machine spindle and is fixed in it in the ordinary way. This wheel hereinafter called
spindle wheel suppo_ the case on its back. The case is prevented from revolving
with this wheel and the spindle by two bars or their equivalent bolted to the sides of
the case and embracing the frame of the drilling machine. Vertically under the
spindle wheel and facing the same, I place another bevil wheel, hereinafter called
tapping wheel. This wheel has cast on it a hollow boss extending to both sides, part
at the back revolving in a bearing of the case while that on the face is prolonged so
that it enters a recess in the boss of the spindle wheel and can rotate in it.
Inside this hollow boss I place a spindle fitted at its lower end with any
ordinary suitable socket or clip for the square of the screw tap. This spindle is
grooved and driven by the tapping wheel by means of a key, so that it can slide down
and follow the tap. It is held up by means of a helical spring surrounding it and
acting against a collar at the top of the sliding spindle.
The other three bevil wheels are arranged at right angles to the two wheels
before described, two of them being horizontally opposite each other to the right and
left of the vertical spindle, and the other at the back. The latter always retains its
position and is always in gear with the spindle wheel. The other two are arranged
so that their bosses can slide in the bearings of the case, and their bosses are connected
by means of collars levers and rods to a handle, so that by moving the latter both
wheels are moved simultaneously to one side or the other. One of them, for
instance that on the right hand, is of such size and so placed that when pushed to the
left it gears both with the spindle wheel and the tapping wheel, so that when in this
position the tapping wheel is driven from the machine spindle in one direction. The
other wheel on the left hand is of such size and so shaped that when pushed to the
right it gears with the tapping wheel and the third horizontally supported wheel,
which as described is always in gear with the spindle wheel. The latter then drives
the tapping wheel through two intermediate wheels and in the opposite direction to its
previous rotation. The horizontal wheels being connected' as herein before described,
bringing one into gear draws the other previously out of gear, so that by moving the
handle the workınan can rotate the tapping wheel and tap at his option in one direction
for tapping and in the other for screwing the tap out of the tapped hole. The reversing
and sliding of the tapping spindle being effected in the apparatus itself, the latter can
be applied to any ordinary drilling machine spindle with screw feed or other similar
spindle.
The bevil wheels may have any ordinary form of tooth, but by preference I make
the teeth broad at the base, and pointed at the top, or wedge shaped, so that they have
a tending to push the wheels out of gear and the workman has to hold them in gear
with a certain pressure upon the handle. By this means he can feel the pressure
required to drive the tap and if the latter meets with more than ordinary resistance,

page_text: for instance by reaching near to the bottom of a third hole, he can feel the increased
push of the wheel teeth and instantly reverse the tap. When ordinary wheel teeth
are used, a short shaft may be arranged fitted with adjustable levers, one of which is
moved by a collar or equivalent part in the sliding tapping spindle when the tap has
entered to the required depth into the hole and thereby turns the shaft, the other lever
being so arranged that this turn of the shaft brings the lever against the handle or
levers and rods connecting the sliding bevil wheels and draws them out of gear.
Dated this 26th day of March 1889.
EMMOTT & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Apparatus for Tapping Metals.
I JOHN MILEY of South View Highfield Lane, Keighley in the County of York,
Foreman Draughtsman 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 :-
My invention relates to the tapping of holes with screw taps and consists in an
improved portable apparatus for tapping holes by means of a drilling machine spindle
or other revolving spindle to which the apparatus can be attached.
On the sheet of drawings appended hereunto,
Fig. 1 shows a vertical section of the tapping apparatus.
Fig. 2. a side view and
Fig. 3. a plan of the same.
Fig. 4 a section of the tapping spindle along line A. B. of figure 1 shewing the tap
holder.
The apparatus consists of a square box or case hereinafter called case made in two
halves a, a, vertically divided and joined together by bolts b, b. The case is formed
with bosses or bearings at its sides bored out for the reception of the turned bosses of
five bevil wheels c, d, e, f, g. The wheel c. hereinafter called spindle wheel has
a shank c', formed on or attached to its hosses c² which shank fits into the socket
of a drilling machine or other revolving spindle and is fixed in it in the ordinary
way. This wheel supports the case a, a', on its back. The case is prevented from
revolving with the spindle wheel or the tap by means of a bracket h, in which a
spindle or bar is fixed that slides in a boss attached to the drilling machine
frame or to the saddle of a radial drilling machine when the apparatus attached
to the latter or by equivalent means, the holding attachment being arranged to
suit the machine to which the apparatus is attached. Vertically below the spindle
wheel c is placed the bevil wheel d hereinafter called tapping wheel. This wheel is
cast with a hollow boss on each side, the boss d' at the back revolving in a bearing of
the case while the boss d² on the face of the wheel is prolonged and enters a
recess in the boss c² of the spindle wheel c. and can rotate in it. Inside this hollow
boss d¹ d² 1 place a spindle 1, of somewhat smaller diameter than the bore of the
top part of the boss and formed at its lower end with a socket slotted for the
insertion of the adjustable tapholder i. shewn in plan by figure 4. The spindle 1. is
grooved and driven by a key fixed to the tapping wheel d. or equivalent driver so that
it can slide down and follow the tap.
A collar . is fixed in the case by means of a thumbscrew k¹ which collar fits the
spindle and a washer is fixed to the top of the latter and prevents the spindle from
dropping out of the boss d¹³. A helical spring m. is placed round the spindle 7,
between the collar k. and the socket which presses the spindle downwards and
serves to exert pressure on the tap at starting as hereinafter described.
The other three bevil wheels e, f, g, are arranged at right angles to the two
wheels c and d, the wheels e and being horizontally opposite to each other to
the right and left of the vertical spindle and the wheel g being at the back of the

page_text: same. The latter always retains its position and is always in gear with the spindle
wheel c, and clear of the tapping wheel d. The wheels e and are arranged so that
they can slide in their bearings in the case and are formed with collars at the
ends of thoir bosses between which and the case light helical springs e² f' are placed
that draw the bevils e and foutwards and hold them out of gear with the other
bevils unless pushed into gear in the manner hereinafter described.
The wheel is. placed centrally with the bevils c and d and of such size that
when pushed to the left it gears both with the spindle wheel c and the tapping
wheel but without coming into gear with the wheel which is placed a little out of
centre towards the left as shewn on the plan figure 3 so that when thus in gear the
tapping wheel & and spindle are driven from c through f in a contrary direction to
the rotation of the machine spindle to which the apparatus is attached.
The bevil wheel e is slightly smaller in diameter and its centre line placed somewhat
lower than that of the wheel f. as shewn on figure 1 also slightly out of centre
towards the back, as shewn on the plan figuro 3, so that when the wheel e, is pushed
to the right it comes into gear with the wheel g and the tapping wheel d, without
coming into gear with the spindle wheel c.
When thus in gear the tapping wheel and spindle are driven from through
the two wheels g and e in the same direction as the machine spindle driving the
wheel C and in a contrary direction to its previous rotation.
Lugs n. n are cast on the side of the case a¹ to which levers o and o¹ are attached
by pins. The levers o. and o¹ are connected by a bar p. with stud pl passing through
the handle the end of which is inserted into a slot of the case a. The levers o. and o¹
are fitted with tail pins . bearing or the plugs s. and s¹ in the wheels e. and f. By
moving the handle to the left the wheel is pushed into gear, the wheel e being held
out of gear by the spring e, while by moving the handle g to the right the
wheel e is brought into gear, the wheelf being pushed out of gear by the wheel
teeth and spring f and held by the latter, adjustablo stops t and t¹ being provided
for the levers o and o¹ to prevent the wheels from being pushed too deep into gear.
By moving the handle the wheels e and are thus brought alternately into gear and
drive the tapping spindle in the manner hereinbefore described either in the same or
the opposite direction to the machine spindle to which the apparatus is attached, so
that by moving the handle the workman can rotate the tapping spindle and tap at his
option in one direction for tapping and in the other for screwing the tap out of the
tapped hole. The reversing and sliding of the tapping spindle being effected in the
apparatus itself the latter can be attached to any ordinary drilling machine spindle
with screw feed or other similar spindle.
The bevil wheels are preferably made with short teeth broad at the base and rather
tapering and rounded at the top so that they have a tendency to push the wheels out
of gear and the workman has to bold them in gear with a certain pressure upon the
handle. By this means he can feel the pressure required to drive the tap and if the
latter meets with more than ordinary resistance, for instance by reaching near to
the bottom of a blind hole, he can feel the increased push of the wheel teeth and
instantly reverse the tap. A short shaft may be arranged at the side of the case
fitted with adjustable levers one of which is moved by the socket of the tapping
spindle 1. or equivalent part when the tap has entered to the required depth into
a hole and turns the shaft, the other lever being arranged to rest against the
handle q. so that this turn of the shaft moves the handle and draws the respective
bevil wheel out of gear.
The apparatus being attached to the machine spindle and the tap fixed in the
holder, the hole to be tapped is brought under the tap and the latter inserted.
The machine spindle is then screwed or fed down till the spring m. is compressed.
The machine spindle may be revolving while brought down as the tapping spindle is
not rotated as long as the reversing handle is not moved, both wheels e and being
out of gear. The handle 7. is then moved to the side required for driving the tap for
tapping and when the tap has entered the hole far enough its rotation is reversed by
shifting the handle to the other side and the tap screwed out of the hole.

page_text: 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,
Firstly. The arrangement or construction of self contained apparatus for tapping
holes in metals attachable to drilling machine and similar spindles substantially as
hereinbefore described and illustrated by the drawings.
Secondly. An apparatus attachable to drilling machine and similar spindles for
tapping holes in metals containing a bevil wheel (c) attachable to said spindles and a
bevil wheel (d) with long boss containing a tapping spindle in sliding connection
with the same in combination with three other bevil carrier wheels and reversing
mechanism so arranged that the wheel d is driven from the wheel c either through one
or through two carrier wheels according to the position of the reversing handle
substantially as herein before described and illustrated by the drawings.
Thirdly. In apparatus for tapping metals arranged as specified in the proceeding
claim the arrangement of the carrier wheels alternately put into gear with the
wheel d and of the reversing mechanism in such a manner that each carrier wheel
works itself and remains out of gear with the wheel d unless held in gear by hand
by means of the reversing handle substantially as hereinbefore described and illustrated
by the drawings.
1000
EMMOTT & Co.,
Agents for the Applicant.
A clerical error in the address of the Applicant, in the original specification,
having been amended by the Patentee, with the consent of the Comptroller, the printed
Specification will now read as shown below:-