Improved Apparatus for Cutting Screw Threads in or on Articles.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improved Apparatus for Cutting Screw Threads in or on Articles.
I, ALFRED GEORGE MELIUISHI, Manager to Messrs. William Cook & Co.,
Engineers, Limited, of Gothic Works, Salamanca Street, Vauxhall Walk,
London, Machinists, Lathe and Tool Manufacturers, do hereby declare the nature
of this invention to be as follows:
-
This invention relates to certain means or appliances by which screw threads
can be cut in or on articles of metal, and the invention has for its object to so
construct the machine that a motion is imparted, say, in a forward direction to
cut the thread in or on the work at a slow speed and in a backward direction
to release itself from the work at a much greater speed, and to accomplish this
reverse rotation of the screwing tool by means of a pulley always revolving in
the same direction and without the use of single and crossed belted overhead
motions as has hitherto been required. Moreover to accomplish this reverse
rotation at different ratios by the mere act of the operator in feeding the work
to the tap and withdrawing it from it without any knowledge or skill on his part,
the engaging mechanism being of such a character as to reverse the motion
without shock and allow of the tapping tool stopping altogether if the resistance
with which it meets in performing its work is more than it can accomplish with-
out breaking this latter part of course depending somewhat upon the judgment
of the operator.
For the purpose of this invention, I mount a tap tool or threaded die on the
projecting end of a shaft supported in a head stock, and make the machine
horizontally as a lathe, or vertically as a drilling machine. Upon this shaft
is a variable speed pulley running loosely upon said shaft, this pulley contains
a triple sun and planet train of epicyclic gear in compound order, one sun wheel
in the train being so mounted upon the spindle as to become a member of the
train and revolve with them, or be held stationary causing the planetary wheels
to revolve upon it and reverse the rotation of the shaft. The said sun wheel has
on either side of it a friction cone, and is slidable on the shaft by means of a
lever attached to the part on which the work is placed, and by its movement
towards or away from the tapping tool the sun wheel is caused to revolve, or
remain stationary, or to slip as desired.
The socket for holding the work may have a shoot or duct by which small
articles, such as nut blanks or other irregular exterior shaped articles can be
arranged superposed and on edge, the lower one in succession being centralised
with that of the tap tool or threaded die ready for the forward movement when the
screw thread has to be cut; when this is effected the slidable socket is drawn
back by the hand appliances leaving the threaded nut upon the tap or in the
threaded tool, the distance of travel being such that the nut comes in contact
with a wall of the socket or head, and is temporarily held over an opening from
and through which it can fall during the reverse motion of the socket or head.
The action of the clutch gear is preferably automatic such as by the clutch
lever being in connection with a racked rod operable by suitable gear 'by the

page_text: first motion hand wheel, or it may be discretionary by allowing the clutch lever
to be operated by the attendant.
By this invention, nuts, collars, socket ends, and other small appliances can
be screw threaded as desired, and if such articles be of circular shape, the lower
part of the shoot or duct may be provided with means for automatic clamping
and releasing during aud after the operation.
The socket can be of a shape to suit the article to be screw threaded, whether
fed in succession from a shoot or duet, or by hand.
Improved Apparatus for Cutting Screw Threads in or on Articles.
I, ALFRED GEORGE MELHUISH, Manager to Messrs. William Cook & Co.,
Engineers, Limited, of Gothic Works, Salamanca Street, Vauxhall Walk,
London, Machinists, Lathe and Tool Manufacturers, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
--
This invention relates to certain means or appliances by which screw threads
can be cut in or on articles of metal, and the invention has for its object to so
construct the machine that a motion is imparted, say, in a forward direction to
cut the thread in or on the work at a slow speed and in a backward direction
to release itself from the work at a much greater speed and to accomplish this
reverse rotation of the screwing tool by means of a pulley always revolving in
the same direction and without the use of single and crossed belted overhead
motions as has hitherto been required. Moreover, to accomplish this reverse
rotation at different ratios by the mere act of the operator in feeding the work
to the tap and withdrawing it from it without any knowledge or skill on his part,
the engaging mechanism being of such a character as to reverse the motion
without shock and allow of the tapping tool stopping altogether if the resistance
with which it meets in performing its work is more than it can accomplish with-
out breaking; this latter part of course depending somewhat upon the judgment
of the operator.
For the purpose of this invention, 1 mount a tap tool or threaded die on the
projecting end of a shaft supported in a head stock, and make the machine
horizontally as a lathe, or vertically as a drilling machine. Upon this shaft
is a variable speed pulley running loosely, this pulley contains three sun and
planet trains of epicyclic gear in compound order, one sun wheel in the train
being so mounted upon the spindle as to become a member of the train and
revolve with them, or be held stationary causing the planetary wheels to revolve
upon it and reverse the rotation of the shaft. The said sun wheel has on either
side of it a friction cone and is slidable on the shaft by means of a lever attached
to the part on which the work is placed and by its movement towards or away
from the tapping tool the sun wheel is caused to revolve or remain stationary
or to slip as desired.
The socket for holding the work may have a shoot or duct by which small
articles such as nut blanks or other irregular exterior shaped articles can be

page_text: arranged superposed and on edge, the lower one in succession being centralised
with that of the tap tool or threaded die ready for the forward movement when the
screw thread has to be cut; when this is effected the slidable socket is drawn
back by the hand appliances leaving the threaded nut upon the tap or in the
threaded tool, the distance of travel being such that the nut comes in contact
with a wall of the socket or head and is temporarily held over an opening from
and through which it can fall during the reverse motion of the socket or head.
The action of the clutch gear is preferably automatic such as by the clutch
lever being in connection with a racked rod operable by suitable gear by the
first motion hand wheel, or it may be discretionary by allowing the clutch levor
to be operated by the attendant.
By this invention, nuts, collars, socket ends, and other small appliances can
be screw threaded as desired, and if such articles be of circular shape, the lower
part of the chute or duct may be provided with means for automatic clamping
and releasing during and after the operation.
The socket can be of a shape to suit the article to be screw threaded, whether
fed in succession from a shoot or duct, or by hand.
My invention will be understood by reference to the annexed drawings which
represent a machine for screw tapping nuts internally.
Figure 1 part sectional elevation of the machine complete for tapping nuts
and the like.
Figure 2 end elevation of chute and receiver, and Figure 3 part sectional
elevation showing how the grips are operated when circular appliances are to be
serew threaded internally or externally, the cutter being of the necessary form
and shape.
The
A, base of standards B, B', supporting fast and loose pulley shaft C from which
the motion of the spindle D is obtained by strap E on the drum F keyed to the
spindle D on the front end of which is the tapping die or cutter G.
standard B has a projecting ear H from which a pivotted lever I hangs a portion
of same being provided with gimballs J within an annular groove of a slider K
free to rotate and to be moved end on upon the spindle D. Each end of the
slider K is cone shaped, as at L, M, one to engage in a cone shaped opening of
the standard B and the other to enter a cone shaped opening of a block N keyed
upon the spindle D. The slider K is provided with wheel teeth 1' engaged by
a series of pinions Q, Q, carried by axle pins R, R, from within the drum F,
a second set of pinions S, S, are upon the axle pins R in gear with teeth upon the
block N. The lever I has a rod T connected to it and this by teeth on part of
its length gears into a pinion 1 or the spindle of a hand wheel V for movement
of a traveller W which can be slid to and fro upon the supporting check X.
This traveller W by its chute Y has within it a series of superposed blanks which
drop therefrom singly in succession, or when the leaf or retainer a Figure 2 is
moved for the purpose, each blank as it falls bears against the back portion of
the hollow in the traveller as an abutment against the action of the tapping tool
or cutter G and as the cutting is completed the traveller W is drawn back by
hand and the nut so cut and still upon the cutting tool takes a position over the
opening, at this time a continued movement of the hand throws the cone M
into contact with the block N and this by the gears S cause the spindle D to
reverse its motion and so unscrew the cutter tool from the nut at a greater speed
than that at which it entered and cut the thread.
In action, the drum always travels in the same direction as before stated, and
the spindle D is driven by the pinions S, S, gearing into the teeth of the block N
when the cone L is wedged in the cone opening of the standard B', this occurring
through the movement of the traveller W and the pinion and rack lever T
for the cutting operation.
The reverse travel of the cutter for its removal from the nut is effected by the
reverse action on the lever I which throws the slider K along disengaging the
cone Land putting the cone M into contact with the cone opening of the block N

page_text: which fixes the block N and thus through the pinions Q and S a reverse motion
of the spindle D and cutter G is caused to release the nut as the traveller con-
tinues its backward motion, the nut dropping down through the gap Z into a
receptacle.
Figures 2 and 3 represent a modification of the traveller such as for round
articles, say, washers to be threaded.
The discs are supplied from a chute Y on to a leaf a which is slotted at a
certain part of its length to allow the disc to fall singly and to take a position
between the gripping jaws b, b, within which it can be jammed tight by an
operation on the screw so that when motion is imparted to the traveller the
superposed discs remain supported by the leaf. When the traveller is being
drawn hack the washer remains upon the end of the cutter for a portion of the
travel and when the abutment of the traveller reaches the washer a grip will be
formed between the two and the washer will become released by the reverse
movement of the cutter G, the traveller is then drawn back to its fullest extent
the grippers are opened for the reception of a fresh disc to be similarly operated
upon and so on in succession.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. The improved apparatus for eutting screw threads in or on articles as shown
at Figure 1 of the annexed drawings in which the chief features are the geared
sun and planet motion operating within a drum having a continuous travelling
motion in one direction, the internal pinions put into and out of action by the
movement of a slider having coned ends, for the purpose described.
2. In combination with a screw thread cutting machine as shown in Figure 1,
the connection through the lever I to the traveller for effecting the movement
of the blanks in succession and bringing them to the cutter tool by hand motion
in the manner described and substantially as shown.
3. In combination with a continuous motion drum and stationary spindle,
the means by which motion is given to the toothed block N as and for the
purpose described and when enclosed with the continuous travelling drum and
effecting the reverse rotation of the block N and spindle D.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said Alfred George Melhuish.