CERTAIN IMPROVEMENTS IN THE MACHINERY TO BE EMPLOYED IN MAKING NAILS, BRADS, AND SCREWS
Year: 1827

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
TYNDALL, of Birmingham, in the County of Warwick, Gentleman, send
greeting.
WHEREAS His most Excellent Majesty King George the Fourth, by
His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Eighteenth day of December, in the year of our Lord
One thousand eight hundred and twenty-seven, in the eighth year of His
reign, did, for Himself, His heirs, and successors, give and grant unto me,
the said Thomas Tyndall, my executors, administrators, and assigns, His
especial license, full power, sole privilege and authority, that I, the said
Thomas Tyndall, my executors, administrators, and assigns, or such person
or persons as I, the said Thomas Tyndall, my executors, administrators, and
assigns, should agree with, and no others, from time to time and at all times
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, an Invention communicated to be by a certain Foreigner
then residing abroad for "CERTAIN IMPROVEMENTS IN THE MACHINERY TO BE
EMPLOYED IN MAKING NAILS, BRADS, AND SCREWS;" in which said Letters
Patent is contained a proviso that if I, the said Thomas Tyndall, should
not particularly describe and ascertain the nature of the said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and seal, and cause the same to be inrolled in His Majesty's High
Court of Chancery within six calendar months next and immediately after
the date of the said in part recited Letters Patent, that then the said Letters

page_text: Patent, and all liberties and advantages whatsoever, thereby granted, should
utterly cease, determine, and become void, as in and by the same, reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance, with the said proviso, I, the said
Thomas Tyndall, do hereby declare that the nature of. the said Invention, and
the manner in which the same is to be performed, are particularly described and
ascertained in and by the Drawings hereunto annexed, and the following
description-thereof (that-is-to say):-
These Improvements in the Machinery to be employed in Making Nails,
Brads, and Screws, consist, in the first instance, of a certain combination of
mechanical parts, by which rods of metal, in passing between a pair of rollers,
are shaped into the approximate figure of the intended nail, brad, or screw,
and which, after being so formed, are cut asunder between a pair of shears at
the ends of the several intended nails, brads, or screws, and these pieces are
afterwards further pointed and headed, or otherwise brought to their ultimate
figure, by means of dies placed in a rotatory cylinder, which several parts of
the mechanism are worked by toothed wheels, cams, and levers, as will be fully
described and exhibited in the accompanying Drawings.
The second part of the Invention consists of a new arrangement of mecha-
nism by which the threads of screws may be cut to any degree of obliquity or
form; that is, an original screw may be generated, or any description of
thread copied, by a very simple 'adjustment of the apparatus, as will be
explained hereafter.
In the Drawings accompanying this Specification, Figure 1 is a hori-
zontal representation of a complete machine (as seen on the top side) for
forming the nails, brads or screws, in the first instance from rods of metal-
and afterwards for pointing and heading the same. Fig. 2 is a vertical
view (drawn geometrically) of the end of the said machine, the fly wheel
being removed, similar letters of reference denoting corresponding parts. of
the machine in these and the four following Figures. a, a, is the main shaft,
to which the fly wheel 6 is affixed. A part of the main shaft is divided into a
two-leaved pinion c, c, which takes into the peculiarly formed teeth of a cog
wheel d, d, fixed on the shaft e, e, and by means of the rotation of the main
shaft all the other parts of the machine are put in action. Fig. 3 is a vertical.
section taken through th machine parallel to the end view, Fig 2, in the
situation of the dotted line A, A, in Fig 1, in which the forms of the pressing
rollers designed for shaping nails or brads from the rod of metal are seen, and
also the situation of the dies in the rotatory cylinder for pointing and holding, and
the levers for heading the same. It is, however, to be observed that the rollers

page_text: and dies exhibited in this Figure are designed for formning nails or brads, and
would require to be exchanged for rollers and dies slightly differing in shape
from these shewn when the machine is to be applied to making blanks for
screws. Fig 4 is another section taken vertically, parellel to the preceding in
the situation of the dotted line B, B. in Fig 1. This Figure shews the
peculiar form of cogs or teeth of the wheel d, and the two leaves of the
pinion c, c, taking into the same, which, as the main shaft a revolves, causes
the wheel & to be driven round, and consequently the other evolutions of the
machine to be performed through the agency of the toothed wheels f and g.
the former of which is fixed on the shaft e of the toothed wheel d, and the
latter on the shaft of the dio cylinder h, both these toothed wheels being
principally shewn by dots in this Figure.
Rotatory power being applied to the main shaft of the machine, the rod of
metal for making the nails is to be introduced through the guides i and passed
between the rollers k, l, shewn in the section Fig. 3, when the inequalities of
the upper roller le will press the rod as it advances into the forms of a series of
wedges m, m, m, each of which is intended to constitute one nail. The
foremost end of the rod being by these means protruded forward, it enters the
circular groovej of the cylinder h, which is situated exactly opposite to it (as
shewn in Fig. 1), and as the cylinder revolves the partially formed nail passed
into the die, as in Fig. 3, and is there held while it is cut off, the manner of
doing which will be further explained. The detached Figure 5 represents a
pair of the dies as seen on the upper side. drawn off the full size; they
consist of two pieces of steel n and o, cut with rabbeted ends suited to the
form of the intended nail. These dies are mounted in longitudinal grooves in
the revolving cylinder h, as seen in Fig 1, the die n being firmly fixed in the
groove, and the die allowed to slide freely. A spring p, affixed at the end of
the cylinder h, acts in a notch at the end of the sliding die, as seen in Fig. 1,
drawing it back, and consequently opening the dies. This is the position of the
dies shewn in the auxiliary, Fig. 5, and as the cylinder revolves the nail intro-
duced into the groove, as above described, passes into the dies at the opening j
The movement of the cutter q is effected by means of a camr, affixed to the main
shaft a, as seen in Figs. 1 and 2; and as that-shaft revolves, the cam r lifts the
lever s, attached to the shaft t, which causes the shaft t to vibrate on its pivots;
and to produce the movement of the upper cutter q through the medium of the
short lever u, seen in Fig. 3. The partially formed nail having been thus cut
off from the end of the rod by the cutter q, and the cylinder h being stationary
at this time, the next movement of the cylinder carries the nail up to be headed!
As the cylinder revolves the end of the sliding die a comes against the curved.

page_text: inclined planet, affixed to the side of the standard seen in Fig. 1, which
causes the die o to be forced inwards, and by thus closing the dies the nail is
moulded into the required form which it is designed to assume, and at the
same time it is held securely for the purpose of being headed. By raising the
levers in the manner before described, the heading block w, attached to the
shaft t, is depressed, which brings the die x on the top of the nail and produces
the head. Let it here be observed, that although the main shaft a is to be
turned by an uniform rotatory motion, yet, in order to give time for cutting
and heading the nails, the rollers k, l, and the cylinder h, must be made
stationary at intervals. This is effected by the peculiar form of the teeth of the
wheel d, which allow the leaves of the pinion c to move through a portion of
their revolution without driving the wheel forward, and which takes place at
the time that one of the cams of the wheel is raising the lever s, and the
cutting and heading is performed in the way above described. The further
rotation of the cylinder h carries the nail to the opposite situation to which it
was introduced into the cylinder, where a small punch, acted upon by a spring
through the medium of a lever y, projects it from the dies, as shewn in Fig 3.
The tails of these levers extend out at the end of the die cylinder h, and are,
during the revolution of the cylinder, pressed inwards by a snail-formed piece,
as shewn in Fig 2; and when the cylinder arrives at that part of its rotation
where the nail is to be projected, the end of the then acting lever y slips from
the smaller to the larger diameter of the snail. The action of these levers
will be perfectly understood by reference to the auxiliary Fig 6, which shews
the die cylinder in section taken longitudinally.
Having described the method of forming the rod of metal into wedge-shaped
pieces, and cutting those pieces asunder, and afterwards heading them, it will
be necessary to cbserve that the rod of metal should be made hot previous to
its introduction between the rollers; this, however, is not absolutely indispen-
sible, as the nail may be made from the rod in a cold state, but heating it will
facilitate the operation. The form of the dies employed for moulding and
heading the nail must depend on the kind of nail intended to be made; the dies
are therefore capable of being removed from the cylinder and header with
facility, when others may be placed in their stead. In moulding the blanks
for screws both of the rollers must be formed with semicircular grooves, and
with suitable recesses for the heads, and when cut asunder the perfecting of
the head is performed by the heading die.
I now proceed to describe the second part of the Invention (vizt, the
method and machinery for cutting threads on screws, which are exhibited in
the 7th and following Figures of the Drawings. The apparatus resembles

page_text: a turning lathe in some of its prominent features,, of which Fig. 7 is a
horizontal representation, Figo 8 a vertical view taken. longitudinally. a, a, is
the bed; b, b, the mandrill frame supporting a mandrill rigger and gearing,
resembling an ordinary lathe. c is the foot puppet, of the usual construction;
d, a slide rest held firmly to the bed by the weight e. A peculiar novel feature
in this part of the Invention is the method of producing a reciprocating motion
of the slide rest carrying the cutter, and which contrivance also affords a
means of giving any required obliquity to the thread of the screws. The
wheelf being locked to the rigger by a peculiarly formed, bolt, (as will he
described hereafter), and the rigger made to revolve in the direction of the.
arrow, the wheel h and the mandrill i, to which it is affixed, will: be turned in
the oppisite direction. At the back end of the mandrill there is a small
pinion k, which takes into a rack 1, l, affixed to. a, sliding plate m, m, shewn
particularly in the horizontal view. A bar 0, 0, attached to the slide rest, is
connected to the guide bar n by having a notch on the under side through which
the guide bar slides, as seen in the detached Fig. 9. It will now bo perceived
that by turning the rigger in the direction of the arrow the pinion .will cause
the rack bar and the sliding plate to recede (that is) to move in the direction
of its arrow, and by this movement the guide bar n standing.obliquely, will be
made to draw the slide rest by its connection to the bar o towards the mandrill
frame. By these means the cutting tool, as it moves with the slide rest toward
the puppet head, generates and cuts a screw thread upon the blank p, .as
shewn in Figure 8. When the thread has been cut sufficiently far upon the
blank P the action of the machine is reversed for the purpose of carrying the
slide rest with the cutter back again, which is effected by the following
means: As the plate m slides a tappet q; screwed to the plate, strikes against
a tooth g at the lower end of the perpendicular shaft r, shewn most evidently
in the auxiliary Fig. 10, by which means that shaft is turned round, and a hori-
zontal lever s, affixed. to the top of the said shaft r, being connected by a
link t to the sliding pin u, that pin is forced inwards, and a locking bolt w, the
arm of which is connected to the pin by passing through, a mortice hole, is (by
the sliding of the pin), withdrawn from the wheel ƒ and projected into the
wheel. By these means the rigger is now locked to the back train of
toothed wheels as shewn in the section Figo 11, and the mandrill is now made
to turn the reverse way. This movement of the pin is promoted by the logger
head above falling over, as shewn by the dotted lines in Figo 8. The
reverse action having been thus obtained, when the slide rest with the cutter
and the sliding plate with its rack has run back to its extent, another tappet
y, raiso.l. upon the sliding plate, will be brought against the before-mentioned

page_text: tooth at the lower part of the perpendicular shaft r, and turn it the reverse
way to that above described, which again locks the front wheelf to the rigger.
Previous to the returning movement of the slide rest it is necessary that the
point of the cutter should be withdrawn from the screw. This is done by the
action of the before-mentioned perpendicular shaft r, as will be described. The
cutter is attached to the vertical arm of an elbow lever, shewn in the auxiliary
Fig 12, which lever 1 vibrates upon centres 2, and the rising of the horizontal
arm of this lever causes the cutter 3 to fall back-from-the-screw. In the
horizontal representation of the machine shewn at Fig 7 there is a sliding
bar attached by a joint to an arm extending from the perpendicular shaft r
before mentioned, consequently the action of this shaft, in reversing the
motion of the slide rest (as described above), causes the bar to bo
slidden to and fro." Upon this bar there are two small tappets 5, 5,
capable of being adjusted to any required distance apart, which tappets,
as the bar slides, strike against a pallet 6 on the shaft 7. Attached to
this shaft there is a small forked lever 8, carrying the pin 9, which passes
through a horizontal slot in the tail of the lever 1. When the cutter is
in action the lever 8 is nearly in a perpendicular position, and is held there
by a lever with a logger head 10, seen also in Figs. 7 and 8; but on pushing
back the bar for the purpose of withdrawing the cutter from the screw, the
tappet 5 strikes the pallet.6, and throws the shaft 7 with the logger head 10
and the forked lever 8 in the opposite position, by means of which the pin 9,
sliding in the slot, raises the tail of the lever 1, and throws back the cutter.
When the slide rest has moved back to its extent for the purpose of repeating
the cut the action of the perpendicular shaft r, as above described, draws the
bar to the left, when the other tappet 5 strikes the pallet 6, and throws over
the logger head as before, bringing the cutter again into action, where it is
firmly held by the più of the forked lever, as before explained. In order to
encrease the depth of the cut a ratchett wheel 11, in Figs. 7 and 8, is affixed
to the screw of the slide rest, which ratchet wheel, coming in contact with a
stationary pall 12 at every return of the slide rest, sets up the screw a small
portion of a revolution. To prevent the point of the cutter being, broken
when it is withdrawn from the work, the tappet q on the plate m is made to
advance by very small degrees at every successive cut, so as to stop the action
of the cutter a little earlier every time. The method of doing this is shewn
in Fig 7, and in the enlarged representation of the tappet, Fig 13, the upper
plate being removed in this Figure to exhibit the parts, within. There is a
small lever 13, to which a pall 14 is attached, and this pall is pressed into the
ratchet 15 liy a spring. Now it will be perceived that by pressing the tail of

page_text: the lever 18, which takes place by its striking against the framework on every
advance of the sliding plate, that the rachet will be pushed one tooth forward,
the tappet by that means becoming elongated, and consequently the distance
between that and the other tappet shortened. This machine is designed for
generating and cutting original screws with threads of any required obliquity
and figure, and is therefore particularly applicable to the cutting of screw
taps, one of which is represented in Fig. 8 as under operation, but it is also
applicable to the cutting of screws for other purposes..
In witness whereof, I, the said Thomas Tyndall, have hereunto set my
hand and seal, this Seventeenth day of June, in the year of our Lord
One thousand eight hundred and twenty-eight