CERTAIN WHEELS WHICH, WHEN COMBINED TOGETHER, WILL CONSTITUTE A MOVING POWER OF GREAT FORCE, BY THE APPLICATION OF WHICH TO MANY ENGINES, MACHINES, AND MACHINERY THAT ARE NOW SET IN MOTION BY STEAM, WIND, WATER, OR ANNUAL POWER SAID KNOWN POWERS
Year: 1811

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, TIMOTHY
SHELDRAKE, of the Strand, in the County of Middlesex, Mechanick, send
greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Fifteenth day of June, in the fifty-first year of His reign, did
give and grant unto me, the said Timothy Sheldrake, my exors, adñiors, and
assigns, His special licence, full power, sole privilege and authority, that I, the
said Timothy Sheldrake, my exors, adñiors, and assigns, during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England and Wales and the Town of Berwick-upon-Tweed, my
new Invention of "CERTAIN WHEELS WHICH, WHEN COMBINED TOGETHER, WILL
CONSTITUTE A MOVING POWER OF GREAT FORCE, BY THE APPLICATION OF WHICH TO
MANY ENGINES, MACHINES, AND MACHINERY THAT ARE NOW SET IN MOTION BY STEAM,
WIND, WATER, OR ANNUAL POWER, THE EFFECT OF THE SAID KNOWN POWERS WILL
BE GREATLY ENCREASED, AND THE LABOR OF MAN OR HORSES THAT ARE NOW
EMPLOYED IN THE SALD ENGINES, MACHINES, OR MACHINERY WILL BE DIMINISHED;
THAT THE SAME WHEELS SO INVENTED BY ME MAY BE INTRODUCED IN PART OR IN
THE WHOLE INTO MANY ENGINES, MACHINES, OR MACHINERY, FOR WHATEVER USES
THEY MAY BE EMPLOYED, INSTEAD OF THE WHEELS AND PINIONS BY WHICH THE SAID
ENGINES, MACHINES, OR MACHINERY ARE GENERALLY KEPT IN MOTION; THAT THOSE
WHEELS WHICH I HAVE INVENTED WHEN SO INTRODUCED WILL WORK WITH MUCH
LESS FRICTION AND GREATER VELOCITY THAN THOSE WHICH ARE USUALLY EMPLOYED;
THAT, IN CONSEQUENCE, LESS OF THE MOVING POWER WHICH IS EXERTED UPON THE

page_text: SAID ENGINES, MACHINES OR MACHINERY WILL BE WASTED, AND LESS TIME WILL BE
EMPLOYED; OF COURSE THE EFFECT OF SUCH ENGINES, MACHINES, OR MACHINERY WILL
BE GREATLY ENCREASED;" in which Letters Patent there is contained a proviso
obliging me, the said Timothy Sheldrake, under my hand and seal, to cause a
particular description of the nature of my said Invention, and in what manner
the same is to be performed, to be enrolled in His Majesty's High Court of
Chancery within four calendar months next and immediately after the date of
the said recited Letters Patent, as in and by the same, relation being there-
unto had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Timothy Sheldrake, do hereby declare that my said Invention consists of two
sorts of wheels, which may be made of any materials of which the wheels of
machinery in general can be made, and which may be made of any size or
sizes that may be necessary to adapt them to the machinery to which they
are to be applied or into which they are to be introduced, and which are de-
scribed in the Specification and in the Drawings hereunto annexed.
The properties of these wheels are such that when one of each sort is duly
proportioned and adapted to each other, they will constitute a moving power
greater than can be produced by any other wheels of the same size; and in
that case they will, and when two wheels of the sort which I call passive
wheels are properly adapted to each other they also will, perform their evo-
lutions in less time and with less friction than any other wheels of the same
sizes. And these wheels may be combined together in a variety of ways, so as
either to constitute simple engines of great power, or the most complicated
machinery, still possessing greater power than similar machinery when con-
structed with wheels of any other description. The superiority of these wheels
depend upon peculiarities in their construction and application which are to be
understood by reference to two general laws in mechanics; viz:-
First, that a heavy body moving down an inclined plane will proceed with
a velocity proportioned to its own weight and the steepness of the plane down
which it proceeds; and that such heavy body, of any given weight, will exert
a degree of power as well as velocity which will be greater in known propor-
tions as the angle of the plane approaches to the perpendicular line. This
law is well known to all mechanics, and those who are not acquainted with
mechanics will find it explained in all the elementary treatises on the subject.
Secondly, when the teeth of wheels are cut in diagonal lines upon their sur-
face instead of been cut on lines parallel to their axis, whatsoever power will
turn a parallel tooth in a given time will in the same time drive or turn a diagonal
tooth the diameter of whose square is the same the whole length of its inclined

page_text: plano or diagonal line, to whatever length that inclined plane or diagonal line
may extend, provided all other circumstances are equal, and that the friction
which will be opposed to the motion of a diagonal tooth for its whole length is
little more than will be opposed to the motion of the parallel tooth for one turn
only. This law I believe that I have discovered, as I have not found it men-
tioned in any book, seen any trace of it in any machinery, or met with any ono
person who knew it till I had demonstrated it. It constitutes a l'eading реси-
liarity of my Invention which every man who is competent to make machinery
of this kind will comprehend, and those who cannot comprehend it as a general
principle cannot be competent to construct any machinery which depends upon
the application of that principle.
3)
I call the wheels of which my Invention consists one the active and the
other the passive wheel, because the first contains in itself a degree of power
which is distinct from the extraneous power that may be applied to set it in
motion, and which inherent power may be encreased in the construction of the
wheel in a degree almost unlimitted, and according to the will of the maker
and the nature of the machinery it is intended to make; but the second, tho'
it possesses a great degree of power under some circumstances I call the passive
wheel, because when it is connected with the former it communicates that power
which it receives from it either directly to the body which is to be finally acted
upon or to any other part of the machinery, which communicates with that body.
First, to make the active wheel I proceed in the following manner:-Let
Figure 4 be a pillar of cast iron or any other proper material. Its length,
thickness, and weight must be proportioned to the machine of which it is to
be part and the power which it is intended to produce. Let' its axis bo
vertical, and let so much of its surface as will come in contact with the passive
wheel to cut into teeth whose direction shall be inclined vertically towards the
horizon, and upon an angle proportioned to the power which it is intended to
give the machine, observing that the nearer the direction of the teeth is to the
perpendicular line the greater will be the power and the velocity of an active
wheel of any given dimensions. It is of no consequence whether the upper
or lower or any other part of the pillar is chosen for the teeth. The size of
the teeth must be proportioned to the size of the machine of which the wheel
forms a part, and the number of course must be limitted by the size of the
pillar; but as the weight of the pillar constitutes the inherent moving power
of the machine, it will in general be found most advantageous to have it as
large and contain as great a number of teeth as the general size of the machine
will admit of. When this is done, let it be placed upon its axis, and the
said axis placed or fixed into or upon firm bearings. Having determined what

page_text: shall be the size of the active wheel, and the number of teeth it shall con-
tain, I procure a block of wood of a proper size cut to the intended length of
the teeth, and smooth at both ends. Upon one end I strike a circle equal to
the extreme circumference of the wheel, and divide it into the number of
teeth which are to be made by lines passing through the centre. I then
strike a circle within the square of each of the teeth, so that the center shall
be equidistant between the circumference of the wheel and the sides of the
tooth and the bottoms of the spaces, one to be equal to the bottom of the
circle. This part of the proceeding is represented by the red lines at Figure 1.
I then find another line which, when passing through the teeth, will enable
me to strike a circle on each tooth that shall touch the extreme circumference
and each side, and thus describe part of a circle for the outside of each tooth,
as represented by the black lines in Figure 1. I then cut a paper into the
size of the whole face of the block, so that the same shall either form a square
or a rectangular oblong, according to the dimensions of the wheel as described
by Figure 2, which is drawn on the same scale with the wheel in Figure 1. I
then place one foot of the compasses at the bottom of one end of this paper,
and describe thereon the quarter of a circle, the longest the paper will allow,
as described in Figure 2. I subdivide this into as many parts as will enable
me to find the angle of inclination I intend to give the teeth, which in Figure 2
is 70 degrees; and having found this line I draw a parrallel to it as many lines
as will describe the number of teeth marked upon the end of the block. The
paper is then to be applied to the block that is to form the wheel, so that one
end of the teeth, as described upon the paper, shall correspond with the teeth
as described on one end of the block, as before mentioned, and then the teeth
are to be marked from the paper upon the face of the block, and finished
accordingly. If the teeth are to be finished in wood or other material by hand,
they must be finished to the exact form that has been described; but if they
are to be cast, the pattern maker must be careful to leave so much metal as
will allow them to be trimmed down to the form which I have described when
finished. The size of the active wheel, the number and size of its teeth, and
the angle at which they are to be cut, are perfectly arbitrary; but it is neces-
sary that these circumstances should be determined before the passive wheel
is made; that is to say) the passive wheel may contain any number of teeth
that may be required; but the size of that wheel cannot be arbitrary, it must
be governed by the number of teeth it is intended to contain; to find the size.
of which wheel proceed in the following way:-Take a paper of any length
that may be required whose breadth is equal to three diameters (three being,
as I conceive, the best general rule) of a tooth of the active wheel, and as

page_text: described in Figure 3, lay this paper with the side A close and parallel to the
side B of that paper described in Figure 2, on which the teeth of the active
wheel are described, and so as that the bottom C of Figure 3 should be on the
same line with the bottom D of the Figure 2; describe on this paper, for the
passive wheel, the spaces and teeth to any number required, so as to corre-
spond with those on the paper of the active wheel, and as described in
Figure 3. If you draw lines parallel at equal distances to whatever length it
may be necessary to extend according to the number of teeth the passive
wheel is to contain, you will then have plans of the faces of the two wheels,
which will correspond when laid upon each other; but as the papers lay sido
by side the lines will diverge from each other at the point of intersection, tho
one going to the right, the other to the left. When two of those wheels,
which I have called passive, are intended to work together with their axis
parallel, some additional precautions will be necessary either in constructing
or in fitting them up. It is obvious that this kind of wheel partakes of the
nature of a screw, so that if one was to work upon a fixed counterpart the
wheel would move towards one side with a power and velocity proportioned to
the angle on which its teeth are cut, either till it had worked itself compleatly
out of the machine, or 'till some obstacle suflicient to stop it was opposed.
When two of these wheels work together, as when a small wheel is made to
turn a large one which is to raise a weight, the latter is in fact fixed till the
moving power, acting upon the small wheel, overcomes the resistence of the
larger. The small wheel so forced into action will not bear directly upon
the larger 'till it has moved obliquely in the line of its tooth, and met with
some resistance that overcomes that oblique tendency. It then proceeds strait
forwards; but the larger wheel then moves obliquely in its turn till it meets
with some resistence that overcomes it, and then both wheels with work freely
in the direction parallel to their axis. When the teeth of these wheels are cut
at angles from five to ten or fifteen degrees from the perpendicular line, or from
seventy-five to eighty-five degrees from the horizontal, this lateral resistance is
easily overcome by fixing a friction roller in any part upon which cither of
the wheels is found to bear; this immediately destroys the lateral pressure,
and the wheels will immediately work freely in a direction parallel to their
axis. Where velocity of motion only is wanted this arrangement may be suffi-
cient; but where great power is wanted, or the teeth of the wheels are cut on
angles more oblique, this will not be sufficient, but a different arrangement
must be adopted. I then use what may be called double inclined-plano
wheels, to make which I proceed as follows; viz, I strike a line round the
centre of the face of my wheels, and form the teeth to diverge from each

page_text: other, but their points to meet in the centre line, as will be understood by
inspecting the annexed Figure 10. The teeth then resemble wedges or
double-inclined planes; they work freely together, and according to the well-
known laws, that opposite forces destroy each other, and when forces oppose
cach other in an oblique direction, they assume a new line of motion at a
medium between the two; they proceed in a direction parallel to their axis
without any impediment whatsoever. When two passive wheels are intended
to work together, the same manner of laying them out should be followed,
taking care that one should go the right, the other to the left, by which means,
when the teeth are brought together, they will work with truth and facility, and
the number of teeth in these wheels may be unequal in any proportions. It
must be understood that what I have called the active wheel should always
have its teeth cut, so that their length should go as nearly as possible parallel
to its axis; but the passive wheels should have their teeth cut on the same
angle of inclination from a straight line, but with their length going as much
as possible across their axis, so that the axis of an active and a passive wheel
must always be at right angles to each other. The passive wheel has but one
action to perform, therefore it is not indispensable that its teeth should have
the circular form, tho' I do usually give it; but I am aware that if so much of
its teeth is circular as comes in contact with the active wheel, it is in general
suflicient; and I conceive there may be cases where it may be advantageous to
preserve as much of the flat surface of the teeth of the passive wheel as its
action with the active wheel will allow; for this reason I think considerable
latitude may be allowed in forming the teeth of the passive wheel, tho' I think
every deviation from the circular form in the teeth of the active wheel will be
injurious. Having laid down the teeth of the passive wheel according to the
rules above described, the rest of the wheel, or the pattern of the wheel, is to
be be finished in the usual way, and when cast is to be chipped or trimmed
'till it is finished, and is found to work true with the active wheel it is to be
moved by.
Having described the rules, by observing of which any person who is com-
petent to perform works of this kind may make these wheels, of any size,
power, or proportions which they may have occasion for, I shall add such
further information as may be necessary to apply them to any machinery in
which they may be used.
Figure 4 represents an active wheel compleat. A, the wheel in the centre
part of the pillar, with teeth cut on an angle of seventy degrees.-N.B. Teeth
may be cut either in the upper or lower part of the column instead of the
centre, if any circumstances in the machinery or the situation should render it

page_text: desirable. B, B, blocks constituting the upper and lower part of the active
wheel; C, end of the lower block turned to fit into a socket in the framework
or other proper part of the machinery; D, upper part of the same wheel, like-
wise shouldered and turned to work in a socket which is to be fixed in the
frame or any proper part of the machinery; E, a continuation of the same
wheel, which is squared, and may be made of any form that can be necessary
to connect it with the moving power, whether that is a winch, windlass, water-
wheel, or any other power. This may be done at the bottom instead of the
top, or the moving power may be originally communicated to it at any other
proper part of the pillar at the discretion of the maker. These parts constituto
one wheel, and I sometimes make them all in one piece, which I think the
best way when it can be practiced; but when it cannot, I make them in three
or more separate parts, and when they are so made, I have them cast with a
square hole through the centre, which enables me, after they are finished, to
pass a square bar of iron or other proper material through it, and fixed them
altogether, when they constitute one wheel as much as if they had been made
all in one piece.
Figure 5, a passive wheel placed in the position it must stand when con-
nected with the action wheel, the square hole in the center showing that its
axis is horizontal, and stands at right angles with the vertical axis of tho
action wheel.
Figure 6, perpendicular section of the socket in which the upper end of the
active wheel works.
Figure 7, horizontal view of the same socket.
Figure 8, horizontal view of the socket in and on which the active wheel rests.
Figure 9, all the above parts put together to show how they are connected.
N.B. E, in Figure 4, may either be squared, as represented, so as imme-
diately to take either a single or double lever across when that kind of moving
power is wanted, or it may be the drum head of a capstan when this power
constitutes part of a capstan, or it may have a small passive wheel squared on
it, which may be turned with a wheel not like the active wheel, and turned by
a horizontal axis, which may be worked by a water wheel or any other moving
power which may be thought necessary.
In witness whereof, I, the said Timothy Sheldrake, have hereunto set my
hand and seal, the Fourteenth day of October, in the year of our Lord
One thousand eight hundred and eleven.
TIMOTHY (L.s.) SHIELDRAKE.

page_text: AND BE IT REMEMBERED, that on the Fourteenth day of October, in
the year of our Lord 1811, the aforesaid Timothy Sheldrake came before our
said Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stampt according to
the tenor of the Statute made for that purpose.
Inrolled the Fourteenth day of October, in the year of our Lord One
thousand eight hundred and eleven.