IMPROVEMENTS IN MACHINERY FOR MANUFACTURING SCREWS
Year: 1877

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents, 66,
Chancery Lane, in the County of Middlesex, Mechanical Draughtsman, for the
Invention of "IMPROVEMENTS IN MACHINERY FOR MANUFACTURING SCREWS."
A communication from abroad by John Adams Kernochan, of Pittsfield, in
the State of Massachusetts, United States of America.
Sealed the 1st May 1877, and dated the 2nd March 1877.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton at
the Office of the Commissioners of Patents on the 2nd March 1877.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
"IMPROVEMENTS IN MACHINERY
County of Middlesex, Mechanical Draughtsman.
FOR MANUFACTURING SCREWS." A communication from abroad by John Adams
Kernochan, of Pittsfield, in the State of Massachusetts, United States of America.
This Invention is more particularly designed for making metal screws having
nicked or slotted heads, and it will here be particularly described with reference to
the manufacture of such screws; but it is also applicable in part to the manu-
facture of other screws, and to cutting screw threads on the ends of rods.
The Invention consists in various novel constructions and combinations of devices
for feeding the screw blanks one by one to a chuck, which holds them while being
screwed, or for feeding the screw blanks or screws to the device which cuts the
nick or slot in their heads.
It also consists in means for centering the screw blanks or rods in relation with
the screw thread cutting dies or devices, and in means for controlling and operating
said dies.
In the application of said Invention to the manufacture of screws having nicked
or slotted heads the screw blanks are introduced promiscuously into an elevated
basin or hopper, from which they are lifted by a rotating device and deposited with
their heads uppermost in a slotted guide, which conveys them one by one, and with
their heads still uppermost, to a drop tube, from the base of which they are separately
taken by a vibrating carrier and passed shank foremost in line with a supply tube,
along which they are pushed lengthwise in a series, and from which they are pro-
jected one at a time by a plunger into the chuck, which holds them while being
screwed. A centering device or tumbler is then brought to bear upon the point of
7077

page_text: the advance and projecting screw blank to centre it in the chuck relatively to the
screwing dies, which then being closed are advanced to cut the required thread on
the blank, suitable rotary motion being at the same time communicated to the
chuck or dies. The dies are then opened and the chuck is caused to liberate the
screwed blank, which drops or is forced out by the action of the feeding plunger
upon the screw blanks in the rear of it, and the dies subsequently retired.
A similar feeding apparatus is employed to conduct the screws or screw blanks
heads foremost up to the saw or device which cuts the nick or slot in their heads,
which latter are then shaved by means of a suitable tool upon a rest arranged to
one side and in front of the chuck which holds the screws or blanks while having
their heads nicked or slotted. In this way and by these means the screw blanks
are threaded and nicked in a most rapid and efficient manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Vincent Newton in the Great Seal Patent Office on the 1st
September 1877.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. IMPROVEMENTS IN MACHINERY
FOR MANUFACTURING SCREWS." A communication from abroad by John Adams
Kernochan, of Pittsfield, in the State of Massachusetts, United States of America.
This Invention is more particularly designed for making metal screws having
nicked or slotted heads, and it will here be particularly described with reference to
the manufacture of such screws; but it is also applicable in part to the manufacture
of other screws, and to cutting screw threads on the ends of rods.
The Invention consists in various novel constructions and combinations of
devices for feeding the screw blanks one by one to a chuck, which holds them while
being screwed, or for feeding the screw blanks or screws to the device which cuts
the nick or slot in their heads.
It also consists in means for centreing the screw blanks or rods in relation with
the screw thread cutting dies or devices, and in means for controlling and operating
said dies.
In the application of this Invention to the manufacture of screws having nicked
or slotted beads the screw blanks are introduced promiscuously into an elevated
basin or hopper, from which they are lifted by a rotating device and deposited with
their heads uppermost in a slotted guide, which conveys them one by one, and
with their heads still uppermost, to a drop tube, from the base of which they are
separately taken by a vibrating carrier and passed shank foremost in line with a
supply tube, along which they are pushed lengthwise in a series, and from which
they are projected one at a time by a plunger into the chuck, which holds them
while being screwed. A centreing device or tumbler is then brought to bear upon
the point of the advance and projecting screw blank to centre it in the chuck
relatively to the screwing dies, which then being closed are advanced to cut the
required thread on the blank, suitable rotary motion being at the same time com-
municated to the chuck or dies. The dies are then opened and the chuck is caused
to liberate the screwed blank, which drops or is forced out by the action of the
feeding plunger upon the screw blanks in the rear of it, and the dies are sub-
sequently retired.
A similar feeding apparatus is employed to conduct the screws or screw blanks
heads foremost up to the saw or device which cuts the nick or slot in their heads,
which latter are then shaved by means of a suitable tool upon a rest arranged at
one side and in front of the chuck which holds the screws or blanks while having
their heads nicked or slotted. In this way and by these means the screw blanks
are threaded and nicked in a most rapid and efficient manner.

page_text: Having thus specified the object and nature of the Invention its description will
now be proceeded with in reference to the accompanying Drawings.
Fig. 1 represents a partly sectional side view of a machine constructed in
accordance with the Invention, and as applied to the feeding of screw blanks to the
dies which cut the thread thereon, to the centreing of said blanks in relation with
said dies, and to the operation of the dies and of the chuck, which holds the
blanks while being screwed.
Fig. 2 is a plan of the same, showing the screw blank centreing device or
tumbler in its retired position and the screw cutting dies as advanced and thrown
open.
Fig. 3 is a plan in part showing the centreing tumbler and screw cutting dies
in reverse positions and relations with the screw blank.
Fig. 4 is an interior side view of certain mechanism for operating the centreing
tumbler.
Figures 5 and 6 are an under view and a longitudinal vertical section respectively
of the screw cutting dies.
Fig. 7 is a vertical transverse section of the machine, mainly on the line, x.
Fig. 8 is a vertical section, in direction of the length of the machine, of certain
means used to pass the screw blanks one by one from the drop tube of the feeder
to the tube which conveys them to the chuck employed to hold them while the
thread is being cut upon their shanks.
Fig. 9 is a longitudinal section upon a larger scale of certain means for operating
the chuck which holds the screw blanks while being threaded.
Fig. 10 is a side view of a machine constructed in accordance with the Invention,
as arranged for feeding the screws or screw blanks to the device which cuts the
necks in their heads.
Figures 11 and 12 represent a side elevation and horizontal section (on the
line 2, 2) respectively of a modified construction of the machine in illustration of
certain automatic devices for driving and actuating the machine by steam power or
other motive agent as distinguished from operating it by hand.
Referring in the first instance to the several Figures from 1 to 9 inclusive,
A. is a bed plate on which are erected side frames B and posts C for supporting the
working parts of the machine; D is an elevated basin or hopper into which the
screw blanks to be operated on are thrown or fed; E is a rotating screw blank
lifter fast upon an operating shaft b, and arranged to work within the basin D. This
lifter is of a forked construction being composed, for instance, of a series of duplicate
radiating teeth or prongs c arranged at a suitable distance apart to admit the bodies
of the screw blanks & between them, while the heads of said blanks rest upon the
prongs, as the lifter is rotated and picks up the screw blanks, which thus are
suspended by their heads on the duplicate prongs. F is a guide against or in
proximity to which the forks c after having picked up the screw blanks move
during the rotation of the lifter. This guide is provided at its upper end, which
is set inclining downwardly in an outward direction, with a groove or passage e
which is covered by a hood Garranged above the upper end of the guide, and which
communicates with an upright or drop tube H. The teeth or forks c of the screw
blank lifter E are so shaped or constructed that when the upper edges of each pair
successively come into line or thereabouts with the upper end or edges of the
grooved guide F, they assume an angle that will cause the suspended screw blanks
to slide off them, and into the groove e with their heads on the upper end of the
grooved guide, and so that they will slide down or along said guide, and said
screw blanks will ultimately be delivered head uppermost into the drop tube H:
The hood G over the upper end of the grooved guide F prevents any screw blanks
which may have been raised by the lifter E in a crosswise position on each pair of
forks c, or in any other position than that which causes them to be suspended
between the prongs by their heads, from passing into or upon the grooved guide F
to interfere with the proper action of the latter, and such hood G further serves to
cause said improperly lifted screw blanks to fall back into the basin D.

page_text: If desired, a spring having a hooked end may be fitted on the hood G or be
otherwise disposed, to prevent more than one screw blank at a time passing into
the grooved guide F, and also to ensure such separate passage of the blanks.
As the screw blanks are passed as described into the drop tube H with their
heads uppermost, they fall by their own weight, one after the other, to the bottom
of the tube, and from thence into a cavity f formed in the inner side or surface of a
carrier I, and opening through the periphery thereof. This carrier receives the
screw blanks one by one as it is required to keep up a supply of them to a chuck J
at the end of a supply tube K, and to keep said tube always full, so that as one
screw blank enters the chuck another blank is deposited by the carrier in the tube
leading to the chuck. The carrier I is arranged to vibrate or oscillate upon an
axis g within a box L. So soon as a screw blank d has been received within the
cavity of the carrier I, when said cavity occupies an upright position, said carrier
is turned on its axis to bring its cavity f in line with a horizontal and corre-
spondingly shaped cavity h (Fig. 1) in the box L, into which cavity / the screw
blank falls by its own weight, and is confined therein by the carrier when the
latter is turned back to put its cavity fin line again with the drop tube H.
When the carrier I is turned to close the tube H and bring its cavity f in line
with the cavity in the box L, the supply of blanks & from the tube H is shut off.
In this way only one screw blank can enter the carrier I at a time.
The carrier I is vibrated backwards and forwards by means of a toe kon said
carrier actuated by reciprocating devices as herein-after described, and a weighted
lever also attached to said carrier. After the screw blank during the vibration of
the carrier I has passed into the cavity h in the box L, through which and in line
with said cavity there is a horizontal tubular passage communicating with the
tube K that leads to the chuck J, and which tube is contained within a hollow
revolving mandril N, a plunger m, Figs. 8 and 10, operated by a sliding and reci-
procating mandril 0, forces said blank through the tubular passage in the box L
into the tube K, which latter by successive actions of the carrier I becomes filled
with screw blanks lying in regular order one behind the other with the points
foremost. At each forward movement of the plunger m one screw blank d will be
forced into the chuck J. The same forward movement of the plunger m which
forces the blank into the chuck J actuates the carrier I to close the tube H which
supplies the carrier with blanks one at a time, and the blank receiving cavity fin
said carrier is at the same time and by the same motion of the carrier brought
opposite the cavity in the box L, thereby causing the screw blank within the
cavity to fall into the cavity h, and be deposited upon the upper surface of the
plunger m. A backward motion of the mandril O is then caused by the means
herein-after described or any other suitable devices to close the chuck, so that it
grips the foremost screw blank on or immediately in front of its head, and the same
backward motion of the mandril O carries back the plunger m, and allows the screw
blank which was resting upon it to fall into the tubular passage in the box L
leading to the tube K, and to assume a position ready to be driven forwards by the
next forward motion of the plunger m. The weighted lever on the carrier I
actuates that carrier to bring its cavity funder the drop tube H during the back-
ward movement of the mandril O, when operating pressure or action is removed
from the toe k on said carrier.
The reciprocating mandril O, or it may be any equivalent device, has secured to it
an adjustable arm P which operates the lower arm of a bell crank Q; this bell
crank Qmoves on an adjustable axle i, and to its upper end, which is provided with
suitable means for adjusting its length of throw, is connected a rod M, the upper
end of which carries a ratchet R; this ratchet receives a vibrating motion, and
thereby intermittently rotates a ratchet wheel Y on the shaft b of the screw blank
lifter E to operate the latter. Instead, however, of this intermittent ratchet
operation of the lifter E, the latter may be rotated by means of a pulley.
The reciprocating sliding mandril O has the plunger m connected with it by an
arm S which is adjustable on or along said mandril to adapt the plunger to different

page_text: lengths of screw blanks. The same arm S or socket portion of the same carries a
bar w which may also be adjustable, and which serves during each forward move-
ment of the mandril O to strike the toe k of the carrier I and cause said carrier to
turn, so that its cavity f is brought laterally opposite the blank cavity h in the
box L, and in line with the tube K preparatory to its return by the weighted lever
to bring the cavity fin line with the drop tube H.
The sliding mandril O may be reciprocated or moved backwards and forwards by
means of a can or any other suitable motion, but it is here shewn as actuated by a
lever T. This lever T not only actuates the sliding mandril O, but also, by means
of a fork n, a cone V, which is free to slide on said mandril, and which as it is slidden
backwards acts upon bell-crank levers that work backwards a tube s arranged
within the mandril O and having attached to it a female cone slide W, which
relieving the spring jaws of the chuck J of pressure, allows said jaw to open and
deliver the advance screw blank after it has been threaded, the clastic construction
of the jaws of said chuck having previously served to hold the blank while being
screwed. Thus it will be seen that the same motion of the lever T causes the screw
blanks to be picked up by the lifter E, and to be transferred by the carrier I with
their heads and points in proper position, and to be conveyed one by one in succes-
sion to the chuck J, and secures them there ready to be operated upon by the centre-
ing and thread cutting devices.
Such previous description explains the mode of bringing the blanks done by one
into the chuck J, but before said blanks can be further operated upon by the dies
for cutting the threads thereon, it is necessary that they should he truly centred in
the chucks. This is secured by a special centreing device, which may be constructed
as follows: Upon a fixed block A¹ (see Fig. 3) arranged to one side of the chuck J
is mounted by a pivot a¹ a centreing pivotted tumbler or lever B, having a centre-
ing cavity at its one end to receive the point of each blank as its shank is pro-
jected through the chuck, and beyond the face of the latter a sufficient distance to
permit the head of said blank being gripped by the chuck. The other end of said
centreing tumbler B' is formed with a flat bearing surface c', by which, as herein-
after described, the tumbler B' is held firmly and rigidly in position while a screw
blank is being centred in and gripped by the chuck. The under side of the centre-
ing tumbler B¹ has a curved slot in it. The back of the block A³ is provided (see
Fig. 4) with a longitudinal groove el, having within it a pointed switch f¹ pivotted
in its rear to the block A, and provided at its back with a fixed guide g¹
Arranged to reciprocate longitudinally within or along and outside of the grooved
block A', is a slide C provided on its inner face with a pivotted lever catch ¹, which
has a stud or pin on its one side near its front end. When the slide C¹ is inoved
forwards in or along the groove e¹ of the fixed block A', the stud slides on and
along the upper surface of the switch f¹ and causes the free end of the lever catch h¹
to enter through an upper opening in said slide the curved slot d' in the centreing
tumbler B. This causes said lever to turn on its pivot a', out of the way of the
thread-cutting dies or tool which will then be advancing to operate upon the screw
blank in the chuck. When, however, the stud i¹ has ascended the switch f¹ (which
then forms a rising incline) and has passed along the guide g¹, it slips off the latter
and so causes the lever catch to drop and disengage itself from the centreing
tumbler B. A reverse or backward motion of the slide C' carries the stud i of the
lever catch under the guide gl and pivotted switch f¹, which latter when passed
drops to its normal position. As the slide C₁ completes its backward movement a
projection on it strikes the centreing tumbler B' and turns it into position to
receive within its centreing cavity b₁ another screw blank in the grip of the
chuck J.
Outside of the fixed block A' is a fixed guard or projection D', between which and
the block A' the slide C¹ inoves. This projection D' is constructed with a flat or
straight surface on its inner side, against which the flat bearing surface c' of the
centreing tumbler B¹ rests when the latter is adjusted as described to receive within
•

page_text: it the point or shank of the screw blank held by the chuck. This locks the centre-
ing tumbler B when turned or adjusted to centre a screw blank.
The centreing tumbler B¹ and other portions of the centreing apparatus may be
attached to and operated by and with the revolving and sliding head of any
screw-cutting machine, or it may be attached to any suitable lathe, and the slide
bringing the work into contact with the dies may be operated by an inde-
pendent lever, or by and with any suitable device thereon, said centreing
device or tumbler can also be used advantageously in centreing the ends of
rods or bars requiring screw threads to be cut on their ends; also for deter-
mining the lengths of such bars or rods projecting beyond the hollow mandril
which carries them. It will suffice here, however, to describe it in connection with
the devices shown in the Drawing for cutting threads upon screw blanks or rods,
and for releasing them expeditiously from the dies in which the threads have been
cut. E is a frame in which the die holders slide, and F a die carrying bed,
arranged to slide within or through said frame; G¹, G¹, are the die holders which
are attached to the bed F. These die holders are each constructed to hold one-half
of a divided or split die at their forward ends, and have each a semicircular recess l
formed at or near their centres. These semicircular recesses are surrounded by con-
'centric lips or walls m¹ (see Figures 5, 6), which in their turn are surrounded by
semicircular grooves or channels n¹. Thus constructed said die holders Care
bound together by a top plate H' constructed to project down within the semi-
circular recesses ¹, so as to form a central stud for the die holders to turn upon, and
being furthermore constructed with an annular rim or lip o¹, which projects down
within the grooves n¹ of the die holders. A central stud 71, a set screw or other
suitable means serve to hold these devices in position on the bed F¹. The die
holders G¹, G', are fitted into the frame E¹ so as to hold them closed while the
bed F is being slidden forwards by a lever I', until the thread has been cut
upon the screw blank held by the chuck J, but when the desired length of
thread has been cut the die holders C¹, G¹, will have been projected sufficiently
far out or in front of the frame E¹ to cause reduced portions s¹ formed on the
outer edges of said holders to be thrown outwards by a spiral spring u¹, which
opens the dies and so releases the screw blank which has been threaded, and allows
the die holders to be carried back again. But before the die holders G³, G³, can be
carried back again, a wedge J', through which the lever I' passes, is raised by said
lever and forced between inclined surfaces at the rear ends of the die holders, so as
to close the forward ends of the die holders. The slide C', which operates the
centreing tumbler B¹, is connected to the rear end of the sliding die bed F, so that
the same lever I controls the die holders G¹, G², through the wedge J and the
centrcing tumbler B¹.
Instead of the frame E¹ being made with parallel sides, as shown in the Drawing,
it may be formed with diverging sides, so that the die holders will be gradually
spread apart as they are moved forwards to provide for cutting threads on tapering
screw sbanks or rods. Furthermore, instead of the sliding die holders herein-before
described, there may be used in connection with the screw blank feeding and hold-
ing devices what is known as a revolving turret head, or a die which is stationary
while cutting the screw, but which after the screw has been cut revolves at a greater
speed than the screw does therein, so as to draw itself off the screw; or any other
kind of screw-cutting die or screw plate may be used.
When the screw or screw blank feeding apparatus herein-before described is used
in connection with devices for slotting or nicking and shaving the heads of said
articles, which is the application of the Invention shown in Fig. 10 of the Drawing,
in which Figure similar parts herein-before referred to in the previous Figures are
indicated by like letters, the plunger m that passes the blank or screw from the
carrier I to the chuck J of the revolving mandril N is reversed in its relation to the
carrier I, so as to feed the screws or blanks with their heads foremost; centreing and
stopping devices similar to those herein-before described may be used to centre and
stop the screw or screw blank when thus fed forward. K¹ is a circular saw for

page_text: nicking the heads of the screws or screw blanks as they are projected through and
held by the chuck J. This circular saw is fast on a shaft which has its bearings in
the upper or free end of an arm or frame L' fast at its lower or opposite end to a
sleeve a on a lower shaft 62, to which rotary notion is communicated, and from
which it is conveyed by means of gears or belt and pulleys. A lever or treadle M
is attached to the sleeve a, by which the circular saw K¹ can be brought into
contact with the head of the screw or blank to be operated upon. A break is or
may be attached to the sleeve a² or arm L¹ for stopping the motion of the revolving
mandril N when the head of the screw or screw blank is being nicked. A counter-
weight c connected with the sleeve a² serves to carry the saw K¹ out of the way
after the screw or screw blank has been nicked.
At or near one side of the chuck J (Fig. 10) is a tool rest N¹ upon which to
operate a tool for shaving the head of the screw or screw blank.
It will be obvious that the apparatus for feeding and nicking and shaving the
heads of the screws or screw blanks may be distinct from the apparatus for feeding
and cutting the threads on said screw blanks, or such two apparatus may be.
connected or arranged to work in regular consecutive relation, as, for instance, by
arranging the basin or hopper D of the head nicking and shaving apparatus under
the chuck J of the blank screwing apparatus, so that as said blanks are delivered
from the screwing apparatus they are conveyed by gravity to the head nicking and
shaving apparatus.
Referring to Figures 11 and 12 of the Drawing, substantially the same apparatus
is illustrated as referred to in the first nine Figures, but instead of the different
operations being controlled by hand or hand levers, as herein-before described, they
are effected in regular consecutive relation and automatically by steam or other like.
power. Thus the revolving mandril N, which may be driven by pulleys and belt or
gear, gives motion by means of gears a³, 63, c³, to a shaft d³, which in its turn
rotates by bevil gears e³, f³, a shaft gs. On this shaft g³ is a crank h³ which serves
to vibrate by its longest slotted arm a T shaped lever A2, which has its fulcrum i³
in a slotted frame piece B². One of the cross arms of this lever has a crooked slot
3 in it, within which is received a pin 13 attached to a sliding rod C² that serves to
actuate a lever D2, by which motion is communicated to the die holders G¹, G¹, and
centreing tumbler B₁; the other cross arm of the lever A² has a crooked slot m³
in it, which slot is mainly concentric with the fulcrum of the lever A². Within
this last named slotted cross arm is a pin n³, by which motion is communicated to
the sliding mandril or sleeve O that in its turn, as herein-before described, actuates
the carrier I for transferring the screw blanks from the drop tube of the basin D to
the tube which conveys them to the chuck J, also actuates the plunger m, which
forces said transposed blanks through the chuck tube. The lower slot m³ in the
lever A² is made mainly concentric with the fulcrum 23 of said lever, to give the
necessary pause or rest to the feed of the blanks along the tube leading to the chuck J
while the latter is holding a blank under the process of being screwed, and the
short concentric curvature of the upper slot of said lever serves to give pause or
rest to the rod Cand lever D* for the screwed blank to drop out of the chuck J. The
lever D, which takes the place of the lever I¹ in the first-described arrangement, is
composed of two opposite arms arranged on the same fulcrum or shaft, the lower
arm of which is forked, and receives through its forked extremity an oblique rod E
that passes through the wedge J' which closes the dies, and is connected with the
die holders G¹, G¹, to reciprocate them. This rod E is arranged to swing or swivel
on one of the posts C as a centre of motion. G2 is an inclined plane pivotted at 73
and controlled by a spring s³ and stop us. This pivotted inclined plane serves to
act on the under end of the wedge J', and close the dies as said wedge moves back
to allow of the shoulder formed by the reduced portions s¹ of the die holders entering
within their frame. Said pivotted inclined plane G³ moves out of the way when
the wedge J¹ comes forward again.
Having now set forth the nature of the Invention of "Improvements in Machinery
for Manufacturing Screws," as communicated to me by my foreign correspondent,

page_text: and explained the manner of carrying the same into effect, I wish it to be under-
stood that under the above in part recited Letters Patent I claim,-
First. The combination of the rotating screw blank lifter, having a series of
duplicate radiating teeth or prongs c, with the basin and its hood G and grooved
guide F, all constructed and arranged to operate in connection with the drop tube,
substantially as described.
Second. The vibrating screw or screw blank carrier I in combination with the
drop tube H and the box L having a receiving cavity h, substantially as specified.
Third. The combination of the plunger m, the supply tube K to the chuck J, the
box L having a screw or blank receiving cavity h, and the screw or screw blank
carrier I, essentially as described.
Fourth. The combination of the sliding mandril O, the arm P thereon, the bell
crank Q, and the rotating screw or screw blank lifter E operated from said bell
crank, substantially as and for the purpose herein set forth.
Fifth. The combination of the sliding mandril O, the arm S, the bar w, and the
toe of the carrier I, essentially as described.
Sixth. The combination with the chuck which holds the work to be threaded of
a centreing tumbler, constructed to operate substantially as and for the purposes
herein set forth.
Seventh. The combination of a centreing tumbler B¹ with mechanism for cutting
the threads on screw blanks, or on the ends of rods, and so that said centreing
tumbler is adjusted into position and moved out of the way by said mechanism,
substantially as specified.
Eighth. The combination of the slide C¹ with the pivotted centreing tumbler B¹,
the switch f¹, the fixed guide g¹, and the lever catch h¹ having a stud or pin i,
essentially as and for the purpose herein set forth.
Ninth. The combination of the fixed guard or projection D¹ with the pivotted
centreing tumbler B, constructed with a bearing or resting surface c¹, substantially
as described.
Tenth. The die holders G¹, G¹, in combination with the plate H¹ constructed to
concentrically enter said die holders, essentially as described.
Eleventh. The combination of the cone or wedge J' with the pivotted or swinging
die holders G, G¹, having reduced portions s¹, and the frame E' in which said die
holders slide, substantially as described.
Twelfth. The combination of the head nicking or slotting mechanism with the
screw or screw blank feeding devices, substantially as herein described.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto set my
hand and seal, the Twenty-ninth day of August, in the year of our Lord One
thousand eight hundred and seventy-seven.
A. V. NEWTON. (L.S.)