AN IMPROVED MACHINE FOR MAKING SCREWS."
Year: 1873

page_text: LETTERS PATENT to Christopher Miner Spencer, of Hartford, Con-
necticut, United States of America, for the Invention of "AN
IMPROVED MACHINE FOR MAKING SCREWS."
Sealed the 14th April 1874, and dated the 19th November 1873.

page_text: Patent for the same, and have made solemn Declaration that I am
the true and first Inventor thereof.
NOW KNOW YE, that I, the said Christopher Miner Spencer, do
.hereby declare that the following Complete Specification, under my
hand and seal, fully describes and ascertains the nature of the said
Invention, and in what manner the same is to be performed in and by
the following statement, reference being had to the accompanying
Drawings where Figure 1 is a plan view of said machine; Figure 2, a
partial sectional view of the chuck made use of; Figures 3 and 4 are
detail views; Figure 5 is a sectional view on the line x, y, Figure 1; 1
Figure 6 is a side view of the tool carriage.
This Invention relates to the combination and arrangement of devices
by which the chuck which holds the work against the tools has a
uniformly continuous motion, provision being made therefor by causing
at the proper time a greater speed than that possessed by the chuck to be
imparted to the screw cutting die, to cause it to follow off the thread cut
by it upon the work, and to the construction of a feed mechanism that
automatically and intermittently carries the stock and operates the
chuck and determines the length of the screw, the object of the
Invention being the construction of a machine in which the operations of a
sizing and shaping the blank for the screw to be made, and cutting off
the screw from the rod shall be performed automatically to the further
advantage, also, of saving the time hitherto lost in stopping and
reversing the motion of the chuck. The revolution of the shaft B by
means of the cam H, and connection b, carries the rod a off the end of a
which the screws are made, along until as much of it as corresponds
with the length of the screw thread to be cut is projected from the
mouth of the revolving chuck A, when by the continued revolution of
the shaft B, the sleeve W by means of the cam L and connection h
compels the chuck to hold the rod a, while by means of the cam T upon 3
the shaft B, the forming tools in the rotating carrier wheel X are one at
a time and as many as are necessary to shape the blank for the screw
brought into operation on the rod a, and then the die m which cuts the
thread on the blank after the blank is ready for it,
The carrier wheel X may have several forming tools, the shape of the 2

page_text: the carrier wheel shall have towards the rod a, while the connection h
influencing the chuck holding the rod shall have lost motion upon the
cam L. In the Drawing one forming tool n is shown to be alternately
advanced with the die m while the rod a is held. After the screw has
been otherwise formed by the forming tools and thread cutting die, the
heading and cutting off tool V is moved by the cam I to head and cut off
the screw from the rod, after which the continued rotation of the shaft B
causes by the withdrawal of the sleeve W the chuck jaws to relax, when
the general operation above described is recommenced. The chuck A
forms part of or is attached to the hollow spindle K, and receives its
motion from the pulley D. The jaws o, o, are hung at v, v, and present
inclined sides to the conical end of the reciprocating sleeve W, as shown
in Figure 2, so as to be closed by the pressure of said sleeve. Within
the sleeve W is the sleeve G having an independent reciprocating
motion, and constructed as shown in Figure 4, so as to grasp the rod a
with friction sufficient to carry the end of the rod past the relaxed jaws
of the chuck while sliding upon the rod, when the same is held by the
jaws until in position to feed again. The carriage 8 having the carrier
wheel X is moved toward and from the chuck A by the cam T, its
reciprocating movement in its track revolving the carrier wheel by
means of a pawl and ratchet, one of which is in the carrier wheel, and the
other in the bed or track, as is common in machines for making screws.
The carrier wheel carries a spindle Q, upon one end of which is the die
m, and upon the other end a roller y, as seen in Figure 4. The die is
held by the clutch fattached to the carrier wheel X, and meshing into
the part m within which is the screw cutting die, and its advancement
when so held or clutched and when brought against the end of the rod a
cuts the thread. When the screw cutting die is released by the with-
drawal of the clutch f, the friction pulley R. by means of the cam Ę on the
shaft B, and the lever F is made to give speed through the roller Y to the
spindle Q greater than the speed of the rod a, and the screw cutting die
is thus run off the thread it has just cut without any diminution of the
speed of the clutch spindle. The friction wheel R is hung in spring or
loose bearings in the head of the frame, so that the lever F grasping its
shaft depresses it so as to make it come in contact with the roller Y.
The belt from the shafting above may be slack when not tightened by

page_text: fraction of an inch is all the movement it requires to bring it in contact
with the roller Y. The die spindle when not hold by the clutch rotates
truly in the carrier wheel.
It will be observed that the step-by-step rotation of the carrier wheel
✗ so as as to bring one or more forming tools attached at intervals to
the carrier wheel, into position for operating on the rod a is entirely
automatic, the cam T causing the slide S to properly reciprocate, and
the reciprocation of the slide causing the engagement and operation of
the pawl and ratchet herein-before referred to, whereby the carrier wheel
or turret is caused to make its step-by-step rotation; this automatic
rotation of the tool bearing turret X is a novel thing, and is a part of
my Invention, whether a cam is used to cause the reciprocation or any
other of the many devices for producing rectilinear reciprocating
motion

page_text: 6. The combination of the clutch bearing turret X, friction roller R,
and cutter V, all constructed and operating substantially as described.
In witness whereof, I, the said Christopher Miner Spencer, have
hereto set my hand and seal, this Eleventh day of October, in
the year of our Lord One thousand eight hundred and seventy-
three.
In the presence of
CHRISTOPHER MINER SPENCER. (L.S.)
WILLIAM EDGAR SIMONDS.