METHOD OF EQUALIZING THE MOTION OF THE SAILS OF WINDMILLS
Year: 1807

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CUBITT, of Bacton Wood Mills, North Walsham, in the County of Norfolk,
Engincer, send greeting.
WHEREAS His most Excellent Majesty King George the Third lid, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Ninth day of May,
in the forty-seventh year of His reign, give and grant unto me, the said
William Cubitt, my executors, administrators, and assigns, His especial
licence, full power and authority, that I, the said William Cubitt, my executors,
administrators, and assigns, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, my new
invented "METHOD OF EQUALIZING THE MOTION OF THE SAILS OF WINDMILLS;" in
which said Letters Patent there is contained a proviso obliging me, the said
William Cubitt, by an instrument in writing under my hand and seal, to
cause a particular description of the nature of my said Invention, and of the
manner in which the same is to be performed, to be inrolled in His Majesty's
High Court of Chancery within one calendar month next and immediately
after the date of the said in part recited Letters Patent, as in and by the
same (relation being thereunto had) may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Cubitt, do hereby describe my new method of equalizing the motion
of windmill sails in manner following, that is to say:-
My Invention consists in applying to windmills an apparatus or contrivance,
which shall call the vanes, constructed or formed in a new and peculiar manner to
regulate themselves, so as to preserve an uniform velocity under those circum-

page_text: stances in which the wind would otherwiso irregularly impel them, as is the case
with sails or vanes of mills of the present construction. I accomplish this object
by forming the vanes (for the sake of lightness) with fewer cross bars or shrouds
than in the common method, and filling up the remaining open spaces with small
flat surfaces formed either of boards or sheet iron, painted, or any other fit sub-
stance, though I prefer and recommend them to be made of a framing of wood
covered over with canvass. I hang or suspend the same on their ends by
gudgeons, pivots, centres, or any other convenient method, so as to open and
shut like valves (for which reason I shall hereafter so call them), preferring
always to have the centre of motion as near the upper longitudinal edge of the
valve as possible, as shewn in the Drawing b, b, Fig. 1, which exhibits a valve
detached. I apply these valves to vanes of the present construction by sus-
pendling them to the cross bars or shrouds of the vane by their longitudinal
edges, fastened thereto by joints or otherwise as may be preferred. These
vanes, constructed of valves as above described, and which are represented in
the Drawing, Fig. 2, present a greater or less surface to the wind according
as it acts with more or less force on them; and if the wind be very strong or
high, the valves, by its impulse, would turn their edges to it, and their surfaces
parallel to the direction of the wind. The vanes would consequently remain
stationary, or at least have but little motion; but to obviate this circumstance
taking place, I apply an apparatus which shall cause the valves always to pre-
sent their flat surfaces to the wind, or such portion of their surfaces as may bo
desirable.
The apparatus which I have usually applied is exhibited in the Drawings,
Figures 3 and 4, which last Figure shews two modes of performing this object,
though it must be evident that various other means may be applied to produco
the same effect on the valves, and I therefore do not mean to confine myself to
those precise modes of effecting it, but consider it unnecessary here to detail
others, as the examples exhibited in the Drawings fully ascertain the sort of
apparatus requisite.
DESCRIPTION OF THE DRAWINGS.
B
to the wind, and their surfaces all exposed at right angles with the direction of
the wind; B, B, exhibit the vanes as close reefed, or the valves with their edges
to the wind, so that it can have no effect upon them except on their edges, which
must be trifling.
In the Drawing the vanes are exhibited as having the whip down the
middle, with valves on both sides, but it is evident that the vanes may be con-

page_text: structed with the whip placed in the usual way, and have valves on one side
only, which is the method I usually adopt in applying them to vanes of the
present form.
Figure 8 represents a side view of the apparatus for regulating the valves;
and Figure 4 is a section of the same, exhibiting two methods of performing this
operation. A represents the shaft, which is bored through its centre to admit
an iron rod B to pass freely through it; one end of this rod is made to turn in
a box C, which is fastened to a toothed rack D, whose teeth take into those of a
pinion E, upon the axis of which is a sheave F, with a groove on its circum-
ference to receive a rope G, to which is hung a weight shewn at H, Fig. 3, and
which must be sufficient to regulate the force of the wind upon the valves,
though no precise quantity of weight can be herein specified, as the same must
be adjusted by experiment, or by the quantity of work to be performed by the
mill. On the top of the rack D is a roller I, which serves to keep the rack
and pinion in the proper depth of geer. The end of the rod B, which turns in
the box C, has a knob or onion on it, by which it can be moved endwise while
it is turning in the box C; on the other end of the rod is fixed a boss or
plate of iron K, with a gudgeon projecting from each side, on which are
the bridles or leaders L, L, which permit the levers M, M, to describe a
curve with their ends while the iron rod B moves in a straight line. N, N,
are two studs or props fixed to the stock O of the sail, on the ends of
which props the levers M, M, move, and communicate their motion to the
racks P, P, the teeth of which take into the pinions Q, Q, on the axis of
which, according to one method herein exhibited, Fig. 5, is fixed a strong iron
stud R, which is attached to a rack or slider S. Iron studs or levers aro fixed
at one end in this slider S by a pin or gudgeon, and at the other made fast to
the valves a, which move on gudgeons as before described. The other method
of regulating the valves is shewn at Figure 6, where, instead of the studs or
levers, the valves may be moved by having pinions fixed to them, and working
with teeth in a rack or slider, as at T. V, V, are rollers to keep the racks P
in their geer.
The operation of this apparatus will be clearly comprehended by imagining
that if the hook 4 on the rope G be pulled down to 5, the sheave F with the
pinion E will turn at the same time, putting in motion the rack D with the rod B,
which will bring the levers M, M, into the position represented by the dotted
lines. The racks P will have turned the pinions Q till the sliders S and T,
with the studs, or levers, or racks (according to whichever method may be used)
are brought with the valves into the position of the dotted lines, in which posi-
tion they are represented as having all their surfaces to the wind; therefore, if a

page_text: sufficient weight to be hung to the hook 4, the weight will descend to 5, and keep
the valves in the situation of the dotted lines; and supposing the wind to blow,
upon them with too much force in this state, they will turn on their gudgeons
and raise the weight, so that the superfluous wind will pass through or. between,
them, without exerting an irregular force upon the vanes so as to produce an; 5
unequal velocity.::
In 'witness whereof, I, the said William Cubitt, have hereunto set my
hand and seal, this Third day of June, in the year of our Lord'
.:.:. One thousand eight hundred and seven.
(Ls.) WILLIAM CUBITT.; 1
AND BE IT REMEMBERED, that on tho Third day of June, in the
forty-seventh year of the reign of His Majesty King George' the Third, the
said William Cubitt came before our said Lord the King in His Chancery
and acknowledged the Instrument aforesaid, and all-and every thing therein
contained and specified, in form above written. And also the Instrument 1
aforesaid was stamped according to the tenor of the Statuto made in the forty-
fourth year of His said-Majesty's reign.
"Throlled the Third day of June, One thousand eight hundred and seven.
*
LONDON
Printed by: GEORGE EDWARD EYRE:and WILLIAM SPOTTISWOODE, batt
Printers to the Queen's most Excellent Majesty. 1855
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