AN IMPROVED PORTABLE HAND ENGINE OR MACHINE FOR THRESHING ALL KINDS OF GRAIN
Year: 1799

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, WILLIAM
TUNSTALL, of Nidd, in the Parish of Ripley, in the County of York, Gentleman,
sends greeting.
WHEREAS His most Excellent Majesty King George the Third, by
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Ninth day of November last past, hath given and granted unto
the said William Tunstall, his exors, adñiors, and assigns, His special licence,
full power, sole privilege and authority, that he, the said William Tunstall,
his exors, admors, and assigns, and every of them, by himself and themselves;
or by his or their deputy or 'deputies, servants or agents, or such others as he,
the said William Tunstall, his exors, adñiors, or assigns should at any time agree
with, and no others, from time to time and at all times thereafter during the
term of years therein expressed, should and lawfully might make, use, exercise,
and vend his Invention of "AN IMPROVED PORTABLE HAND ENGINE OR MACHINE
FOR THRESHING ALL KINDS OF GRAIN," within that part of Great Britain called
England, the Dominion of Wales, and Town of Berwick-upon-Tweed, and
also in His Majesty's Colonies and Plantations abroad, in such manner as to
him, the said William Tunstall, his exors, adñiors, or assigns, or any of them,
should in his or their discretions seeni meet; in which said Letters Patent
is contained a proviso, that if the said William Tunstall should not particularly

page_text: describe and ascertain the nature of his said Invention, and in what manner
the same is to be performed, by an instrument in writing under his hand
and seal, and cause the same to be inrolled in His Majesty's High Court of
Chancery within one calendar month next and immediately after the date of
the said Letters Patent, that then the said Letters Patent, and all liberties
and advantages whatever thereby granted, should utterly cease, determine,
and become void, as in and by the said in part recited Letters Patent, relation
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with and agreeable to the true
intent and meaning of the said proviso in the said Letters Patent contained,
the said William Tunstall doth hereby declare that the nature of his said
Invention, and the manner in which the same is performed, is and are
described and ascertained in the plans, figures, references, and explanations
hereunto written.
The machine is properly worked by two men, but any other power may be
applied to it; the machine also requires two women or two boys, or a woman
and boy, one to spread the corn or grain or sheaves on the feeding board, and
the other to serve the feeder and shake the straw out of the way.
The size and dimensions expressed in the Figures and references will, he
conceives, be found best adapted to general use and conveniency, the scale being
of one inch to a foot. The machine is so constructed as to be easily taken to
pieces, removed, and set up. It is taken to pieces by beginning with No. 1,
and so, progressively, to No. 27; and is set up by beginning with No. 27, and
so, progressively, to No. 1.
Figure 1, elevation of the head of the machine; Figure 2, elevation of the
side of the machine; Figure 3, section of the machine from head to tail;
Figure 4, elevation of the tail of the machine. No. 1 (Figure 3) represents
the feeding board, supported and held fast by iron hooks fixed to the side
frames, three feet wide in the middle, or the length of the rollers, the end
extending as far as is convenient for the former, or for the place to be worked
in; on this board the sheaves, after being unbound, are spread, very thin and
very quick, from side to side, and thence introduced betwixt the roller into the
machine. No. 2, (Figure 3,) a board made to slide or fix before the feeder
to prevent dust from flying into his eyes. No. 3, (Figure 3,) a top or cover,
fastened down, and covering the whole machine above, also to prevent dust; a
space is also left to receive a screw D, Figure 1. No. 4 (Figures 1 and 3)
are gages, made of wood or any other material, of equal size, which are intro-
duced on each side under the ends of the threshing-floor, and slide along the

page_text: groves in the inclined brackets, and raise the threshing-floor in all its parts to
a parralel distance from the frictors of the enneagon. Three setts of these
gages being of different depths are requisite, the lowest of which will cause.
such a distance when introduced into the groves in the brackets and under
the ends of the threshing-floor as will admit beans, or about half an inch, another.
set to raise the floor higher for oats, or about three-eights of an inch; and
another set which will raise the floor still higher, to about two-eighths of an..
inch, for wheat and barley, or nearer still if the grain is not clean threshed; any
greater nicety (and it must be done according to the discretion of the farmer
and the difference of grain) may be had by introducing a slip or more of tin
betwixt the brackets and gages for other smaller seeds. The threshing floor
may be raised by a proper gage. Clover seeds must be carefully introduced
with their stalks into the machine No. 5, Figures 1 and 3). The threshing-
floor is the width of the inner frames, made with two strong ends in their
surface, curved to the circle described by the frictors on the enneagon, and resting
on the length of the gages. The depth of these ends depends upon placing the
brackets and gages more or less inclined. Into the surface of these two ends
are fixed ribs, of any hard and elastic wood or other material, two inches deep,.
one inch over and half an inch asunder, through which the greatest part of the
grain passes, whereby the pressure is diminished, and by its elasticity the
machine always acts without a possibility of being choaked up. The whole
surface, being a tangent to the frictors, must be fixed in a parallel direction, so
as to rise or fall in a line with the centre of the enneagon upon the gages.
The whole floor might, if required to avoid repairs, be made of metal, or the
ribs covered with copper or any other metal, care being taken to prevent any.
sharpness or edge, which may injure the straw or grain. No. 6 (Figure 2) is
a box covering the wheels from dust, held by the feeding board and standing
upon the frames. No. 7 (Figure 1) is a weight, fastened by a ring or hook, or
on a lever, over the end of the spindle of the upper roller, so as to suffer it to
rise a little when any greater quantity is introduced than ought to be. No. 8
is a piece fitted into the frame to pass the two rollers to their bushes, having
a screw through it, which confines the upper roller from rising out of the geer
of the wheel or out of the hook it turns in. No. 9 (Figure 1) is the upper
roller, having a wheel with cogs, to which it is exactly fluted; one end runs
in the left side frame, where it can rise a little, subject to the lever or weight.
The wheel end turns in the hook D, Figure 1 and is kept there by the screw
in No. 8. No. 10 (Figure 1) is a rail with mortices for the frames, and has
a screw and hook, which comes down the middle space where the wheels work.

page_text: No. 11 (Figure 4) is a rail, with mortices at the top of the tail end of the
machine. No. 12 Figure 3) is a pent-house covering where the straw comes
out. No. 13 (Figure 3) is the straw board, made with holes in a quincunx or
other figure, or a trellice or wirework, and reaches up to the threshing-floor
when it rests upon the lowest gage. The holes in this board serve to pass
part of the grain which follows the straw. No. 14, (Figures 3,) the corn
board, made sufficiently large to receive all the grain that passes through the
ribs of the threshing-floor and the holes in the straw board, and this board
empties out the grain into a sack, or what the farmer pleases to have to receive
it. Nos. 15 and 16 (Figures 2 and 3) are boards pannelled into the frames,
and rise over the axle of the enneagon. No. 17 (Figure 2) is an outside
frame, according to the scale of the annexed Drawings or Figures of one
inch to a foot. No. 18 (Figure 3) is the under roller, which turns in
the frames, Nos. 17 and 25, having a cog wheel, to which it is exactly
fluted, and which turns the upper roller. The under roller has also
another cog wheel C (Figure 2), which may be varied in diameter to
accelerate or retard receiving matter or straw by more or fewer cogs, the
number of which is determined by the diameter, so as to reach the distance
required from the centres of the axes of the enneagon and of the under feeder,
and of the wheels B and C, Figure 2. For the revolutions of these rollers or
feeders to the revolutions of the enneagon, the best average seems to be about
one-third, or as forty to sixty-two. Both the rollers should be made of hard
wood, and spindles or axles made to pass through, in order to prevent warping;
or may be made of cast iron, or in parts, which thread or join upon the spindles
or axles. No. 19 (Figure 3) is a half frame, which may be joined to the fran:e
25 by slots or dove-tails, or screws and stands, at E Figure 1), on which the
axle No. 23 must turn when No. 20 (Figure 3) a balance wheel (as large as
the cog wheel) is used, which will serve to steady the axle when it is turned by
a handle at E (Figure 1). By some people it may be deemed superfluous or
unnecessary. No. 21 (Figure 3) is the enneagon or body, which has nine
frictors or ribs, the semi-diameter of which is nearly five times the semi-
diameter of the pinion, overcoming by the space it passes, through its own
gravity, and from such increased velocity it becomes a centrifugal force, adding
to the power of the vis motrix, so as to preserve the acquired motion against a
proportional degree of resistance. This body is made the width of the inner
frames, allowing space for it to revolve without coming into contact with the
side, which would occasion fire. The nine frictors or ribs are firmly fixed to
and screwed, and are one inch square at the angle of so many flat sides, which

page_text: diminish nearly one-third of the resistance of the matter worked upon; and
four frictors or ribs act constantly, by rubbing, or brushing; or forcing the corn
received from the rollers, against the always-parallel ribs of the threshing floor
and roller. This enneagon is.made with a strong. axis, passing through the
ends and middle, which must be all well and solidly put together; the.axis is
turned to run on three buckles, and has shoulders and squares for the pinion A
and the wheel B, and also may have a place for an occasional fly-wheel, if
required, to be fixed on the. outside, which will give more power or weight.
The frictors or ribs may be repaired occasionally as required, or may be
covered square with copper, or made of any strong material, care being had to
prevent any sharpness or edge, which injures. the straw or grain. The pinion
wheel or nut should make not less than six or more than ten revolutions for
each revolution of the great wheel, which should have from one hundred and
forty-four to one hundred and seventy cogs, and the pinion from.seventeen to
twenty-four-cogs. If. required, another. or.. intermediate. wheel may be added,
so as to diminish the great wheel and pinion, preserving always a due pro-
portion of not less than six or more than ten revolutions, which will ease the
force of turning, though it will cause: the men to turn towards the head of the
machine. The wheel B must be made to work with the wheel C, which is
fixed on the axis of the under. roller, in the manner above described, videlicet,
with a greater or lesser diameter,, or with more or fewer cogs, No. 22
(Figure 1). The cog wheel is fixed perpendicular and very true on the iron
axis, and gives motion to the machine by turning the pinion of the enneagon."
The size of this wheel is determined by the motion required, either of six or
ten revolutions, and of the pitch chosen for the size of the cogs, which must be
stronger for wind, horses, or water. The present pitch is seven-eighths of an
inch, and has one hundred and sixty-two cogs, working a pinion with seventeen
cogs, revolving nine and an half times each turn of the wheel. No. 23
(Figure 1) is a strong iron axis, with three or four bearings, as may be required,
when the half frame and balance wheel are used. This axis carries the great
wheel, and two handles, placed at right angles at E and F, which handles must
be made long and strong. No. 24 and 25 (Figure 1) are frames, the same as
No. 17 (Figure 2), joined by rails, as represented in (Figure 4), and marked 26,
and in (Figure 1) marked 27. The hook D regulates the upper roller by
raising it in the geer, and must be placed in the centre of the opposite bush for
that roller, and must never be so low as that the wheels lock together, or so
high that they leave the geer. The frame may be strengthened by braces, or
suited to other conveniences for a winnowing machine, or with a stool or step

page_text: for the feeder to stand upon. Brass or other bushes must be used under the
bearings of the axles, which must be kept down with strong caps and screws or
screw bolts, and holes or conduits contrived to oil the parts that turn.
In witness whereof, the said William Tunstall hath hereunto set his hand
and seal, this Seventh day of December, in the year of our Lord One 5
thousand seven hundred and ninety-nine.
Inrolled the Seventh day of December, in the year of our Lord One
thousand seven hundred and ninety-nine.