AN IMPROVED SCREW CUTTING AND NUT TAPPING MACHINE
Year: 1876

page_text: LETTERS PATENT to Erhard Schlenker, of Buffalo, New York, United States
of America, now of No. 8, Southampton Buildings, London, Manufacturer,
for the Invention of "AN IMPROVED SCREW CUTTING AND NUT TAPPING
MACHINE."
Sealed the 6th April 1877, and dated the 21st October 1876.
PROVISIONAL SPECIFICATION left by the said Erhard Schlenker at the
Office of the Commissioners of Patents on the 21st October 1876.
ERHARD SCHLENKER, of Buffalo, New York, United States of America, now of
No. 8, Southampton Buildings, London, Manufacturer. "AN IMPROVED SCREW
CUTTING AND NUT TAPPING MACHINE."
My Invention relates to machinery for cutting screw threads on bolts or screws,
and tapping or forming the threads in screw nuts, and consists in improved devices
and combinations of parts whereby such machines are rendered more effective and
convenient in use than heretofore.
The main frame is properly constructed to support the parts of the machine. The
said machine is provided with a die head or plate, upon which the dies are adjusted,
and with a carriage in which the bolt to be cut is placed, and which moves on a
bed; a rod having a crank at one end is connected with a movable pin head. There
is a movable pin head in which are fastened pins that move backward and forward
through the die plate, and which in part form the locking clutch for the brackets
wherein the dies are fastened. The dies are supported on a suitable bracket.
The nut-tapping arrangement is placed at right angles with the machine; a hand
wheel or pulley is attached to a pinion shaft connected with a rack bar. The hub
of the said wheel has a screw groove cut upon it for a cord with a weight attached
thereto, which serves to run the carriage back after the bolt is cut. Two collars
upon the said rod are adjusted and held by means of set screws to accomodate
the length of the bolt to be cut. A bracket is attached to the carriage with an eye,
through which the said rod passes, and upon this rod next to the collar is placed a
coiled spring to assist in moving the carriage back after the bolt is cut. A pump
is operated by an excentric upon the cone shaft and spring on the pump rod and
pumps the oil from a reservoir through tubes to lubricate the bolt to be cut. The
oil is then conveyed in other tubes or pipes to a strainer, from which it is discharged
into the reservoir, to be again pumped up for lubrication.

page_text: A movable slide with a coiled wire spring upon it is so arranged that when
drawn out it will allow the pin head to be moved back to withdraw the pins far
enough to unlock the brackets holding the dies, which may then be readily
removed.
A pin in the die bracket is inserted into an opening in a projecting piece or part
of die head or plate to hold the die bracket firmly to the face of the die head or
plate. Steel plate springs press the die brackets against the pins in the pin head.
The bracket moves in an arc of a circle on a pin. The shaft upon which the die
head and pin head are placed and connected with the gearing is hollow, and so
arranged that long bolts may pass into the same.
The bolt to be cut is placed in the jaws of the carriage, which are opened and
closed by the hand lever wheel. The bolt will always be placed centrally to the
hollow shaft and dies, and will be held by the jaws in a firm position for cutting
the thread; it is placed centrally by means of the hand lever wheel. By turning
the wheel the carriage with the bolt to be cut placed in the jaws will be moved
forward, the action of cutting the bolt will move the carriage forward until stopped
by the spring and collar, which have previously been adjusted according to the
As soon as the same is cut the
length of the thread to be cut upon the bolt.
carriage is moved back by means of the weight upon the wheel, the dies are thrown
open, and the bolt released.
The die head has three or more holes for the passage of the pins attached to the
pin head. These pins are beviled at the end, so that when the pins are moved
through the die head the bevil of the pin will strike the die brackets and press
them toward the centre, and the die brackets will be firmly held at any given point,
and will be partly released as the pins are moved back, and the bolt when cut
discharged from the dies. The die bracket is held against the face of the die head by
a pin in a recess on a projection. There is a flat steel spring attached to this pro-
jection at one end to press the die brackets against the pin.
In order to change or take out the dies for any purpose the brackets holding the
dies are removed by moving the slide out from a collar upon the main shaft, and
then by means of a lever or crank the pin head is moved back against a collar upon
the shaft, and the pins that lock the die brackets will be moved back to unlock
them. The pin head is then moved back against the die head, the slide will
resume its position, and prevent the pin head from being moved back any
farther.
The pump is located below the bed of the machine, and is operated by a cam
connected with the cone shaft. The reservoir for the oil has a movable strainer,
and the oil is pumped up and conducted by separate pipes so as to lubricate the
bolt to be cut, and the oil is then conducted to the strainer, which strains it into
the reservoir below, to be again pumped up and used for the same purpose.
The nut-tapping part of the machine is placed at right angles to the bolt cutting
part, by which arrangement I secure the most convenient location, both for
obtaining power and for operating the same. The power is derived from bevil
gear connected with the aforesaid shaft.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Erhard Schlenker in the Great Seal Patent Office on the 21st April 1877.
ERHARD SCHLENKER, of Buffalo, New York, United States of America, now of
8, Southampton Buildings, London, Manufacturer. "AN IMPROVED SCREW CUTTING
AND NUT TAPPING MACHINE."
My Invention relates to machinery for cutting screw threads on bolts or screws,
and tapping or forming the thread in screw nuts. The said Invention consists in
improved devices and combinations of parts whereby such machines are rendered
more efficient and convenient in use than heretofore.

page_text: DESCRIPTION OF THE DRAWING.
Figures 1 and are side elevations of a machine constructed according to this
Invention; Figure 3 is a top view of the same.
Figures 4, 5, 6, 7, show portions of the said machine detached and drawn to an
enlarged scale.
A is the main frame upon which the machine stands; B is the die head or plate
upon which the dies are adjusted; C is the carriage in which the bolt to be cut is
placed; D is the bed upon which the carriage moves; E is a rod, having a crank at
one end connected with the movable pin head E. In this movable pin head the
pins t are fastened; these pins move backward and forward through the die plate,
and form part of the locking clutch for the brackets whereon the dies are fastened;
És is a crank attached to a rod E; F, F, are the dies; and F2, the brackets holding
the same.
G is the nut-tapping mechanism, which is arranged at right angles to the
aforesaid main frame; H is a hand wheel or pulley attached to a pinion shaft
connected with the rack bar H2. The hub of the wheel has a screw groove h for
the reception of a cord, with a weight h¹ attached, thereto, which serves to move
the aforesaid carriage back after the bolt is cut; i, i, are two collars upon the rod E,
which are adjusted and held by means of set screws to suit the length of the bolt
to be cut; jis a bracket attached to the said carriage, with an eye through which the
rod E passes; and upon this rod next to the collar 22 is placed a coiled spring i¹ to
assist in moving the carriage back after the bolt is cut. K is a pump operated by
an excentric s upon the cone shaft S and spring t on the pump rod for pumping the
oil from the reservoir through tubes n and o to lubricate the bolt to be cut. This
oil is then conveyed by tubes or pipes n¹ and o' to the strainer m, from which it is
discharged into the reservoir, to be again pumped up for lubrication.
P, Figure 3, is a moveable slide with a coiled wire spring upon it. This slide
when drawn out will allow the pin head to be moved back to withdraw the pins
far enough to unlock the brackets holding the dies, which may then be readily
removed. This slide when in position prevents the unlocking of the said brackets,
but allows the pins to be moved back as the carriage holding the bolt advances
toward the die head or plate, and opens the dies to receive the bolt, which is firmly
held while in the process of being cut, and is then released by the action of the pins
or by moving them backward.
Q, Figure 4, is a pin in the die bracket, which is inserted into an opening in a
projecting piece or part of the die head or plate to hold the die bracket firmly to
the face of the said die head or plate; s¹ is a projection on the face of the die head,
which has an opening or slit for the pin Q; r, r, are steel plate springs, which
press the die brackets against the pins in the pin head; f is the pin of the die
bracket, which is inserted into the die head, and upon which the bracket moves in
the arc of a circle. The said machine is operated by any suitable power by means
of suitable cone pulleys, gearing, and shafting. The shaft upon which the die head
and pin head are placed and connected with the gearing is hollow, and so arranged
that long bolts may pass into the same.
The bolt to be cut is placed in the jaws of the carriage, which are opened and
closed by the hand lever wheel. The jaws have a right-hand and left-hand screw,
into which the shaft of the lever wheel is placed. The bolt will always be placed
centrally to the hollow shaft and dies, and will be held firmly by the jaws in a
suitable position for cutting the thread. It is adjusted centrally by means of the
hand lever wheel and shaft, which has a screw thread cut thereon, and which fits
in the right and left-hand screw of the jaws of the said carriage. By turning the
wheel H, the shaft of which has a pinion gearing with the rack bar H2, the carriage
with the bolt to be cut placed in the jaws will be moved forward, the bolt is placed
between the dies and held fast, and the action of cutting the bolt will move the
carriage forward until stopped by the spring and collar previously adjusted

page_text: according to the length of the thread to be cut upon the bolt. As soon as the same
is cut the carriage is moved back by means of the weight upon the hub of the
wheel H, the dies are thrown open by moving the pin head back, and partially
withdrawing the pins from the die head and the bolt is released.
The die head has three or more holes for the passage of the pins t attached to the
pin head. These pins are bevelled at the end, so that when the pins are moved
through the die head the bevelled part of the pin will strike the die brackets and
press them toward the centre, and the said die brackets will be firmly held at the
required point, and will be partly released as the pins are moved back, and the
bolt when cut will be discharged from the dies. The die bracket is held against
the face of the die head by the pin Qin the recess on the projection 8¹. There is a
flat steel spring attached to this projection at one end to press the die brackets
against the pin; and when the brackets are released partly by the movement of the
pins backward this steel spring will throw them away from the bolt. This device
is provided for each die bracket.
To change or take out the dies for any purpose the brackets holding the dies are
removed by moving the slide P out from a collar upon the main shaft, and then by
means of the lever or crank E³ the pin head is moved back against a collar upon the
shaft, and the pins that lock the die brackets will be moved back from the face of
the die head or plate so as to unlock them, and they can be taken out without
removing any screw, and after inserting other dies may be replaced. The pin head
is then moved back against the die head, the slide P will then resume its position
and prevent the moving back of the pin head farther than is sufficient to allow the
dies to open to receive the bolt to be cut, and to release the same when cut.
Different sets of dies and brackets are used according to the size of the bolts or
screw.
The pump K is placed below the bed of the machine, and is operated by a cam
connected with the cone shaft. The reservoir for the oil has a movable strainer,
and the oil is pumped up and conducted by separate pipes to lubricate the bolt or
screw to be cut, and the oil is then conducted to the strainer, which strains it
into the reservoir below, to be again pumped up and used for the same purpose.
The nut-tapping part of my machine is placed at right angles to the bolt-cutting
part, as above specified. By this arrangement I secure the most convenient
location, both for obtaining power and for operating the machine. The power is
derived from bevel gearing connected with the shaft of the bolt cutter.
Having thus fully described my said Invention and the manner of performing the
same, I wish it understood that I claim,-
First. The fixed die head provided with the divoted brackets carrying the dies
and springs, operating in combination with the movable head provided with pins,
as above set forth and for the purpose specified.
Second. The heads, the crank rod, the bolt holder, and carriage, the rack bar, and
pinion shaft, and wheel, all constructed and operating as above set forth and for the
purpose specified.
Third. The rod having the collars and springs, the bracket on the carriage, and
the wheel with the screw and weighted cord combined, and operating as above set
forth and for the purpose specified.
Fourth. The machinery for cutting screw threads, consisting of the parts shown
in the accompanying Drawing, constructed, combined, and operating as above set
forth.
In witness whereof, I, the said Erhard Schlenker, have hereunto set my hand
and seal, this Fourteenth day of March, in the year of our Lord One thousand
ERHARD SCHLENKER. (L.S.)