IMPROVEMENTS IN MACHINES FOR CUTTING MACHINE SCREWS
Year: 1883

page_text: LETTERS PATENT to William Phillips Thompson, Fel Iust P. A of the Liverpool.
and London Agency for Foreign Patent Solicitors 6 Lord Street Liverpool in
the County of Lancaster Civil Engineer for an Invention of “IMPROVEMENTS
IN MACHINES FOR CUTTING MACHINE SCREWS a cominunication to him from
abroad by Harrison H Taylor, Manufacturer of Detroit in the county of
»
Wayne and state of Michigan Unital State of Imanica
COMPLETE SPECIFICATION filed by the said William Phillips Thompson at
the Office of the Commissioners of Patents on the 21st March 1883.
WILLIAM PHILLIPS THOMPSON Fel. Inst. P. A. of the Liverpool and London
Agency for Foreign Patent Solicitors 6 Lord Street Liverpool in the County of
Lancaster Civil Engineer "IMPROVEMENTS IN MACHINES FOR CUTTING MACHINE
SCREWS "a communication to me from abroad by Harrison H. Taylor,
Manufacturer, of Detroit, in the county of Wayne, and state of Michigan United
States of America
This invention relates to that class of screw-cutting machines in which the
blanks are held between jaws carried by a rotatable head, and the invention
consists in novel combinations and arrangements of parts, which will be fully
herein-after described in detail and pointed out in the claims, a preliminary
explanation not being deemed essential.
Referring to the accompanying drawings:
Fig. 1 is a top or plan view of a machine constructed in accordance with this
invention.
Figs. 2 and 3 are side elevations of the same looking from opposite sides of the
machine.
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X, fig.
:
Fig. 4 is a transverse section on the line X
Figs. 5, 6 and 7 are detailed views of the feed nut.
Figs. 8, 9 and 10 are detail views showing how the shaft is made to slide
through its drive pinion V.
Figs. 11 and 12 are views of the mechanism for rotating and locking head C.
:

page_text: He ILICUIO
mechanism for shifting the carriage
which carries head C.
Figs. 15, 16 and 17 are detail views of the head and jaws.
Fig. 18 is a detached view of one of the spring cams.
Fig. 19 is a détached view of one of the jaws.
Fig. 20 is a detached perspective view of the belt shifting device, and
Fig. 21 is a detached view of six heads set on the shaft k, set opposite a like
number of pairs of cutting tools.
In these A is the frame of the machine; K is a sliding bed supported in frame A,
and reciprocated by shaft F, which has a screw thread cut on its end, and works
in shear-nut T, which is attached to sliding bed K. Shaft F, may run constantly
in one direction, or be reversed when the cutting mechanism is reversed. G is a
lug cast on sliding bed K, to the upper end of which is pivotted a connecting rod H,
the other end of which is pivoted to an arm n, fastened to the rock shaft I. Rock
shaft I is journalled in bearings in frame A, and has fastened to it another arm V,
to the end of which is pivoted the connecting rod M, the other end of which is
pivoted to a lug cast on a bed X, which rests on frame A and can slide longi-
tudinally on said frame, so that as sliding bed K is reciprocated, sliding bed X will
be also reciprocated, and its motion as it travels toward the right, Fig. 1, will
become slower as arm V and connecting rod M approach a straight line.
8 is a cross piece fastened to sliding bed X, and extending above frame A, z is a
carriage fastened to cross piece s by a dovetail joint, so that carriage must move
with sliding bed X and can also be moved independently at right angles to the line
of travel of said sliding bed X. B B' are uprights cast on carriage z. % is a shaft
journalled in bearings in uprights B B¹. C is a metal head securely fastened to,
and turning with shift k. At each end of head C are cut recesses, in each of
which is set a pair of jaws L L, said jaws being pivoted on pins OO, which run
through said bead and jaws.
Said jaws are provided with recesses on their faces to receive the square head of
a bolt, fig. 17, and the inner ends of said jaws are continued so as to form a
projection, bon each. e e are small spiral springs which hold the jaws L L lightly
closed.
E E¹ are strong springs attached at y to the- uprights B B¹ and each provided
with a projection or can marked x in figs. 15 and 18. At the top of uprights B B'
are small set screws m, by which springs E E¹ may be regulated.
Fastened to the sides of uprights B B¹ are small set screws c, the office of which
will be hereafter explained.
2, fig, 11, is a wheel fastened to one end of shaft k, and having two notches
therein to receive the dog 1, by which shaft k can be firmly held in one of two
positions. 7, fig. 12, is a ratchet wheel fastened to the end of shaft k..
R is a lever sleeved on the end of shaft k, and having thereon a spring pawl, 6,
engaging with ratchet wheel 7, and having also a pivoted arm, 3, which forces
dog 1, down, when the lever R is raised, thereby releasing wheel 2, and allowing
shaft to turn. When lever R is lowered, arm 3, owing to the peculiar formation
of its end, passes under the pin in dog 1, being allowed to do this by the small
supporting spring 5, and, as soon as said arm passes said pin, spring 5 raises said
arm into position to again force dog 1 downwards when lever R is raised. w is a
rack fastened to one side of carriage, and t is a pinion loosely set on shaft r, and
meshing into rack w, U U¹ are friction collars fastened to and turning with shaft r,
and they constantly tend to turn pinion t, and thus move rack w, but as carriage z
is firmly locked to cross pieces by pawl P, said friction collars U U' are only
operative when pawl P is withdrawn from its engagement with carriage by the
contact of the pivoted lever u with a fixed stop or projection u¹ on the machine
frame, which occurs at the end of the backward travel of the sliding bed X, said
lever being carried by the said bed, and its end fitting in a groove in pawl P.
W is a shaft carrying on its outer end a screw cutting die, W₁, and Y is a shaft
carrying at its outer end a shanking or milling tool Y.

page_text: Both of said shafts are journalled in suitable bearings in frame A, are in the
same plane with, and at right angles to, shaft and have on their inner ends
pinions meshing into each other, the pinion on one of said shafts meshing into a
cog-wheel fastened to a shaft driven by a straight and a crossed belt, so that the
motion of said shaft can be reversed.
Shear nut T consists of two sides, each screw threaded and supported by the
curved levers ff, figs: 6 and 7. The inner ends of these curved levers are pivoted
at 17 to a wheel j, on the lower end of post Q, so that when said post is turned by
the handle o shear nut T will either clamp shaft F, or release said shaft.
Post may be operated entirely by the attendant who runs the machine, or it
may be provided with a coil spring d tending to keep nut T open, but prevented
from acting by a stop, i, having the flange h, which engages with arm a fastened
to post Q. When sliding bed K reaches the end of its stroke a cam projection q
on frame A rocks stop i, spring & turns post Q, and nut T is opened, thus releasing
the sliding bed K from shaft F.
In the operation of the machine the attendant inserts a blank bolt, D, fig. 17, in
the jaws at the left. He then raises the lever R, thus turning shaft / and head C
until the said shaft has passed through half a revolution, when dog 1 catches in
a notch in wheel 2 and holds head C firmly.
As head C is turned, the projections b on the jaws, which hold the finished
screw, D', pass below the cams X, and are no longer compressed by the springs E E¹
The projections b strike against the set screw c, as shown in fig. 16, and the jaws
are forced open, thus releasing the finished screw, which falls from the jaws. The
projections on the jaws which hold the blank bolt pass over the cams x, as shown
in fig. 15, and the jaws are compressed or forced together by the power of
springs E E¹, thus holding the blank firmly, and bringing the centre of the head
of the blank in the centre of the jaws. The blank now being opposite the milling
tool Y the nut T is clamped on shaft F, and the blank is fed into the milling tool.
Owing to the relative position of arins n and V. on rockshaft I; and the connection
of said arm V with sliding bed X the blank is fed to the milling tool fastest when
it first meets the tool, and the rate of feed constantly becomes slower, until it ceases
entirely when arm V and connecting rod M are in straight line. The result is
that the milling tool cuts rapidly on that part of the blank which is to receive the
screw thread, where the cut is generally light and where it is not necessary to makė
a smooth finish, (that being given by the screw cutting die), and cuts very slowly
and with increasing fineness towards the head of the blank, where the cut is usually
heavy, and where the work must be left smooth, thus leaving the bolt smooth and
without any burr whatever on the under side of the head.
When the stroke has been completed stop i strikes a cam projection, q, on frame A,
and nut T is opened by spring d, thus releasing sliding bed K from shaft F.
The attendant then depresses lever J, which is fastened to rockshaft I, and thus
brings bed X, into the position furthest from the cutting tool. This causes lever u
to strike against the projecting stop u', and withdraw pawl P from the notch in
carriage, when friction collars U U₁ turn pinion t, and thus slide carriage in
cross piece 8, until the head comes opposite die W¹, when pawl P drops into another
notch in carriage z, and holds the same firmly in place.
The attendant then raises lever J until die W₁ takes hold of the bolt and cuts a
screw thread on it. During this operation the bolt is fed to the die solely by the
action of said die. When the thread is cut the required length on the bolt, n
finger, 20, placed on carriage z strikes a belt shifter connected with the straight and
crossed belts which drive the machine, and reverses the motion of die W', thus
pushing head C away from the die.
By this time the attendant has placed another blank in the jaws which are
empty, and by raising lever J he draws sliding bed X towards the front of the
machine until lever u strikes the stop ul and disengages pawl P from the carriage z,
when friction collars U U', whose motion was reversed when the motion of the

page_text: die W was reversed, again actuate pinion t; and carriage z is moved until head C
is opposite milling tool Y', when pawl P again drops into a notch in the carriage
and holds it firmly.
The attendant now turns head C by raising lever R, the finished screw dropping
from the jaws which held it, the other jaws are firmly clamped on the blank bolt,
and said bolt is cut in the manner described.
When this improved machine is in actual use the shaft k is lengthened so that on
it may be set a number of rotatable heads C, which may be six, as shown in fig. 21,
or more or less, so that a number of bolts may be operated upon simultaneously.
The frame of the machine is widened, carriage z is lengthened and provided with
additional uprights B.B, and as many pairs of cutting tools are set in the frame
as there are heads C on shaft K. This simply increases the size and capacity
of the machine without in any way changing the principle of its construction or
operation.
Having now described the invention as communicated to me I wish it to be
understood that what I desire to secure by Letters Patent is:
1 The combination with the milling tool and the threading die of a screw cutting
machine of the longitudinally reciprocating bed, the transversely reciprocating
carriage, mounted in ways on said bed, the rotatable head mounted on and moving
with said carriage, and provided with blank holding jaws, and mechanism, such
substantially as described, for rotating the head and holding the jaws closed when
they face the dies, and momentarily opening said jaws when they are moved in a
direction away from said dies.
2nd In a screw cutting machine the combination of the longitudinally reciprocating
bed, the transversely adjustable carriage, the rotatable head carried by a shaft
mounted in bearings on the carriage and provided with pairs of blank holding jaws
.normally held closed by springs, a lever connected with the said shaft for rotating
it and the head, and devices for holding one pair of jaws in a closed position when
they face the dies, and momentarily opening such pair of jaws when moved away
from the die, substantially as described.
3rd In a screw cutting machine the combination of the rotatable head C, having
two or more pairs of jaws L with springs E E!, having cam projections x,
substantially as described.
4th In a screw cutting machine the combination of the rotatable head C, the pairs of
jaws L pivoted to said head, and each provided with a projection b with the
springs E E¹, provided with the cam projections 2, substantially as described.
5th In a screw cutting machine the combination of the following devices, to wit:
a milling or shanking tool and a screw cutting die both arranged in the same
horizontal plane, a rotatable head provided with opening and closing jaws and
journalled in a carriage which is capable of transverse reciprocations on a longi-
tudinally reciprocating bed, said head moving in the same horizontal plane as the
milling tool and screw cutting die, substantially as and for the purposes described.
6 The rotatable head C having jaws L L with projections b thereon and pivots O,
combined with springs E E having cam projections x, and the set screws c,
substantially as described.
7th In a screw cutting machine the combination of a longitudinal screw threaded
shaft F, sliding bed K and a shear-nut T with a connecting rod H transverse
rock shaft I, connecting rod M, sliding bed X and carriage z carrying a blank holding
head, substantially as shown and described.
8th In a screw cutting machine the combination of the screw shaft F sliding
bed K carrying a nut adapted to engage and disengage the shafts, connecting
rod H, rockshaft I, connecting rod M and sliding bed ✗, substantially as
described.
9th In a screw cutting machine the combination with a rotating milling tool, a
sliding bed X and a transversely moving carriago z carrying devices for holding
a blank and presenting it to the milling tool, of rod M, rockshaft I having the

page_text: attached arm V pivoted to rod M. arm n, rod H and reciprocating bed K, all
arranged in the relative positions set forth, and operating to move the sliding bed X
toward the milling tool at a decreasing rate of speed, substantially as shown and
described.
'
In witness whereof I the said William Phillips Thompson have hereunto set my
band and seal this nineteenth day of March in the year of our Lord one thousand
eight hundred and eighty three.
W P. THOMPSON (L.S.)