IMPROVEMENTS IN THE MANUFACTURE OF WOOD SCREWS
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, wе, THOMAS
MAYOS WOODYATT, of Cookley, Worcester, Screw Manufacturer, and SAMUEL
HARRISON, of Birmingham, in the County of Warwick, Mechanic, send.
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Eighth day of November, in the second year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
Thomas Mayos Woodyatt and Samuel Harrison, Her especial licence, full.
power, sole privilege and authority, that we, the said Thomas Mayos Woodyatt
and Samuel Harrison, our exors, adiñors, and assigns, or such others as we,
the said Thomas Mayos Woodyatt and Samuel Harrison, our exors, admors,.
or assigns, should at any time 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, our Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF WOOD SCREWS;" in which said Letters Patent is contained
a proviso that we, the said Thomas Mayos Woodyatt and Samuel. Harrison,
or one of us, shall cause a particular description of the nature of our said
Invention, and what manner the same is to be performed, to be inrolled in
Her said Majesty's High Court of Chancery within two calendar months
next and immediately after the date of the said in part recited Letters

page_text: Patent, 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, we, the said
Thomas Mayos Woodyatt and Samuel Harrison, do hereby declare the
nature of our Invention, and the manner in which the same is to be per-
formed, are fully described and ascertained in and by the following state-
ment thereof, reference being had to the Drawings hereunto annexed, and to
the figures and letters marked thereon, that is to say:
Our Invention relates to certain arrangements or combination of mechanical
parts into machines for cutting the threads of wood screws, and also for
facing the surfaces of the heads of wood screws, as hereafter described.
DESCRIPTION OF THE DRAWINGS,
Figure 1 represents a front view in elevation of a machine for worming or
cutting the threads of wood screws, arranged and combined according to our
improvements. Figure 2 is a transverse section of Figure 1. And Figure 3
is a plan of the machine. In each of these Figures the same letters of
reference indicate similar parts, and such is the case in respect to the other
Figures hereafter mentioned. a, a, is the bed or framing of the machine,
which is made of considerable length, in order to receive many screw cutting
machines thereon as heretofore; the nature of this framing a being clearly
shewn in the Drawing, and being similar to the bed of a turning lathe and
other screw machinery, no further description will be necessary according to
the modes heretofore practised. The worms of wood screws have been cut
by means of chisels, which require most careful grinding; and it is well known
that in whole factory for cutting wood screws is often dependant on the good
behaviour of the grinder, otherwise the machines heretofore employed have
been often obliged to stand still for want of the chisels being ground; and
although in some late machines for making wood screws (for some of which
Patents have been obtained) dies with worms or cutters have been made and
employed, still such dies have been of difficult construction, and would not,
as the dies we employ, allow of being made soft and again cut and afterwards
tempered for a very great number of times. Hence, by our arrangement and
mode of constructing and applying dies for cutting or worming wood screws,
when the bars or rods of steel have been once accurately made, the same
may be again and again softened and cut, in order to keep the cutting
surfaces sufficiently prominent; in addition to which they can be sharpened
when hard, by the use of Turkey-stone, with facility. a', a¹, are the two dies;
they are shewn separately on a larger scale at Figures 5 and 6, as well as in-

page_text: their places in the Figures of the Drawings already mentioned. The bars
of steel of which the dies are made should be carefully made, particularly
on the sides, in order when they are taken out and again put into the holders
hereafter explained they shall at all times be correct in their action. The end
faces of the bars of steel a' (on which the worm is cut by a proper screw tool)
have the angles cut off as shewn, and the screw or thread is made in the
centre, which will readily be done by securely fixing the two bars a¹ (which are
to constitute a pair of screw dies) in any convenient manner that the two ends
may be drilled, and then tapped by a suitable screw tool, as is well understood
in cutting screw dies; and in making such dies the two ends do not come
together, but are at a distance apart, leaving a space between the two for the
passage of the metal as it is cut by the dies. Having tapped the dies there
is to be every other thread cut away, in order to act on a less quantity of
metal in cutting, and further to allow of the free passing away of the metal
as it is cut in the act of using such dies. The dies are then to be tempered
and affixed in the machine, by means of the holders b, b, which consist of
two levers moving on axes at 6', by which means the upper ends which carry
the dies a can be closed or opened in the following manner:-c is a lever
moving on an axis at c', as is shewn the the Drawings. This lever is
constantly pressed down at one end by the weight d, and which by a suitable
arrangement of apparatus has a tendency at all times to cause the dies a¹, a',
to approach each other, and when at work those screw dies will constantly
approach each other, and act to cut a screw till the levers 6 come against the
stop e, which will prevent their coming closer together, and consequently thus
prevent injury to the screw or to the machinery. Should the workman or
person attending the machine omit to take out the finished screw and replace
it by a fresh screw blank, to be cut or wound on the other end of the lever c
to that at which the weight is placed, there is applied, a connecting rod and
stirrup iron, by which the person can open the dies by putting a foot into
the stirrup and lifting the weight; for it will be seen that the lever c is
connected to the lower ends of the levers 6, by means of short connecting
links f, ff, as is clearly shewn in the Drawing, the link f being connected
with the lever c by means of a pin joint, and the links f being connected
to the levers 6 by pin joints, as is shewn, the links f¹ and f, f, being connected
together by a pin joint, as will readily be understood by examining the
Drawings; and thus it will be seen that, when the weight is left to act, the
dies a will be pressed in a direction to close them together; and on the other
hand, when the opposite end of the lever c is depressed by the person's foot
who is attending the machine, the dies a will be separated and allow of the
screw which has, been formed thereby being removed. The upper ends of

page_text: the levers b. are enlarged, in order each to have an opening cut through them
for the passage, of the dies a, and the dies a are securely held therein by
means of set screws a², as is most clearly shewn in the Drawing.
By this arrangement and construction of the dies and holders great advantage
will be derived, for one person may attend several machines; for, when once
the screw blank has been supplied, the machine will go on working till the
worm or thread is cut thereon. g is the screw blank holder, it consists of
the axis or spindle g, which turns in suitable bearings 9, as is shewn in the
Drawing. g is a regulating screw, similar to what are usually employed in
screw cutting machines. h is the pulley by which a rotatory motion is
obtained to the axis g, first in one direction, then in the other, in order that
(as the spindle, and consequently the screw blank, is required first to be moved
towards, and the screw blank to enter into and then pass away from the screw
dies a) that that alternating motion may be obtained. The mode of obtaining
such motion to the spindles of two machines is shewn at Figure 7 on a
smaller scale than the other Figures. (1) is a crank on a revolving axis or
shaft driven by a steam engine or other power. (2) is a connecting rod,
which communicates motion to the cranked lever (3) moving on an axis (4)
at the upper part of the room in which the machines are placed. The lever
(3) has slots or openings, in order to vary the position of the point at which
the connecting rod (2) is attached by its pin joint, the other arm of the
lever (3) also having a slot to regulate the position at which the rod (5) is
attached by a pin joint. By this means any requisite portion of a revolution
of the wheel (6) may be obtained and adjusted with great nicety, according
to the varying lengths of screws required to be cut in the same machine, and
the consequent extent of revolution, first in one direction then in the other.
required to be given to the axis g of the screw blank holder. The rod (5)
takes hold of a pin (7) affixed at a distance from the centre of the wheel (6);
hence has the crank (1) moves round it will communicate a regulated quantity
of rotatory motion to the wheel (6), and consequently to the axis g, owing
to the two endless cords or bands (8) being passed round the pulley h in
opposite directions, and made fast thereto, as is shewn in the Drawing. To
the end of the rod (5) is attached the cord (9), which passing over the pulley
(10) comes to a convenient position for the person attending the machine to
draw it downwards, and thus put the machine out of motion." On the axis or
spindle is applied the sliding tube i, there being two flanges formed on
the tube i, between which the lever ; constantly rests; there being a
friction roller carried by the lever j, in order that the sliding tube i
may revolve freely with the axis or spindle g. The tube i is returned
to revolve with the axis g, when a screw is being cut by means of the

page_text: pin k, which enters a groove cut on the face of the plate or projection of
the tube i, as is shewn, and also by the aid of the limbs or chaps of the
holder l, which consists of two levers or chaps 1, 1, moving on axes at the end
of the axis g, as is shown, the two chaps or levers being connected at one of
their ends by pin joints and links to the sliding tube i, the other ends of the
chaps carrying suitable dies or holders m, m, which are shewn separately on
a larger scale at Figure 8, and in their places in some of the other Figures,
the holding dies m being securely held and adjusted by screw nuts on the
screw stems of the holders m, as shewn, n being a screw against which the
head of the screw. blank rests, when it is being held to be cut or wormed, the
screw n being screwed into the end of the axis or spindle g; hence when
the screw blanks are fed into the holding dies they are prevented entering
too far. The person attending the machine, when it is desired to release the
screw which has been cut, forces back the lever, and consequently the sliding
tube i, which will cause the limbs or chaps of the holders to close at that end
and open at the other, and release the screw at the other end; for it will be
seen that the ends of the levers are not directly attached to the part i, but
are connected by the intervention of short connecting links and pin joints, as
is shown. These movements will readily be traced by examining the plan and
front view of the Drawing. The screw blanks are fed into the machine in
the following manner :-o is a slide moving between two guides p, and has a
projection q, in which is formed a groove or recess to receive the end of a
screw blank; and r is a spring which retains the screw blank securely in the
recess; hence when the person attending the machine has pressed down the
stirrup and opened the screw dies, and also opened the screw blank holders,
the slide with a screw blank is slided in the screw dies, and the holding dies
are to be closed thereon, and the machine will go on working correctly.
Figure 9 shows the plan of a machine according to our Invention for facing
up the heads of screw or screw blanks. In this machine the same parts as
those already described are marked with the same letters of reference, the
only difference being that the spindle g is moved constantly in one direction,
having no regulating screw, and the levers 6 carry three chisels s, s, and t,
or facing cutters in place of the worming or screw dies, as are shewn at
Figures 10 and 11 on a larger scale, the upper parts of the levers b being
somewhat differently formed than what is above described. The difference
will readily be understood on examining the Drawing, and the holding dies
are shown on an enlarged scale at Figure 12; in this case they hold the stem
in place of the head. The sliding feeding apparatus has two springs suitably
formed for holding the head of the screw blank, as is shown in the 'Drawing.

page_text: The cutters s, s, face up the under or conical part of the head of the screw, there
being a groove s¹ in the cutting face, and the cutter t faces up the upper part
or surface of the head, all which is clearly shewn in the Drawing, as is
also the shape and nature of the three cutters; and it will only be desirable
to remark, that this machine is placed on similar bearings or framing,
and is to have a weighted lever and stirrup, as explained to the previous
-machine.
Having thus described the Invention, and the manner of carrying out the
same, we would have it understood that we make no claim to any of the
parts separately, and some of the parts may be varied without. departing from
our Invention; but what we claim are the modes of constructing and combining
the various parts into the machines for worming and for facing up wood
screws, as herein described.
In witness whereof, we, the said Thomas Mayos Woodyatt and Samuel
Harrison, have hereunto set hand and seal, this Fifth day of January,
in the year of our Lord One thousand eight hundred and thirty-nine.