A ROTATIVE ENGINE, THE PISTON OF WHICH MAKES A COMPLETE REVO- LUTION, AT A DISTANCE FROM THE REVOLVING AXIS, SHAFT, OR CYLINDER
Year: 1809

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, SAMUEL
CLEGG, of Manchester, in the County of Lancaster, Engineer, sendeth
greeting.
WHEREAS His present Majesty King George the Third, by Letters Patent
under the Great Seal of Great Britain, bearing date at Westminster, the
twenty-sixth day of July last, hath given and granted unto the said Samuel
Clegg, by the name and addition of Samuel Clegg, of: Manchester, in the
County of Lancaster, Engineer, his executors, administrators, and assigns,
special licence, full power, sole privilege and authority, to make, usc, exercise,
a vend, "A ROTATIVE ENGINE, THE PISTON OF WHICH MAKES A COMPLETE REVO-
LUTION, AT A DISTANCE FROM THE REVOLVING AXIS, SHAFT, OR CYLINDER," within
that part of Great Britain called England, His Majesty's Dominion of Wales,
and Town of Berwick-upon-Tweed, for the term of fourteen years from the date
of the said Letters Patent, and to have and enjoy the full benefit and sole use
and exercise of the said Invention during the term aforesaid, subject, neverthe-
less, to a proviso or condition in the said Letters Patent contained, that if the
said Samuel Clegg should not particularly 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 the High Court of Chancery within two calendar months next en-
suing the date of the said Letters Patent, then the said Letters Patent, and all

page_text: liberties and advantages whatsoever thereby granted should utterly cease,
determine, and be void.
NOW KNOW YE, that the said Samuel Clegg, in compliance and perform-
ance of the said Letters Patent, doth, by this instrument in writing under his
hand and seal, particularly describe and ascertain the nature of his said Inven-
tion, and the manner in which the same is to be performed, as well by a
description in writing, as also by delineation of apparatus, that will help to
illustrate or exemplify his principle (that is to say):-
In Figure 1st, A, B, A, B, represents the under side of a circular piece of
cast iron, or any other material which may be found to answer the purpose,
and made according to the scale, or of any other given breadth and depth.
I represents the centre of the circle A, A; and, taking I as the centre, with
any given radius less than the radius of the circle A, A, describe the circle
C, C, and also the circles D, D, E, E, the radius of the circle D, D, being less
than the radius of the circle C, C, and the radius of the circle E, E, less than
the radius of the circle D, D, and that part of the surface which is between
the circles A, A, C, C, is plain; and in the space between the circles C, C, and
D, D, a circular groove is cut, of the breadth C, D, and of any given depth;
and between the circles D, D, and E, E, another circular groove is cut, of the
breadth D, D, and of any given depth less than the depth of the before men-
tioned groove, C, D. The remaining part of the surface A, B, viz, that included
between the circles E, E, and B, B, is cut down to any given depth less than
the before mentioned groove E. Into the groove C, D, a convenient number
of pieces, which the said Samuel Clegg calls segments of a circle, are fitted,
which occupy the entire circular groove, excepting the space L, L, which is
occupied by adjusting screws or springs, which keep the segments close together.
The segments are of the breadth, or nearly so, of the groove C, D, and of a
depth less than the depth of the groove C, D. Those sides of them which
apply to each other are ground plain, so as to make them fit and be air-tight,
or nearly so; and the under surfaces, or those surfaces which are seen in
Figure 1st, are made flat, so that the whole may form one complete flat surface,
excepting the space before mentioned, which is taken up by adjusting screws or
springs L, L, which screws or springs are placed so far below the surface as to
let a roller pass clear of them, as will be mentioned hereafter.
In Figure 2nd, the plate and its grooves are represented by a section at right
angles to the plane thereof (the same letters denoting the same things); and
the lower part of the Drawing represents a chamber or hollow space, which is
circular as to its length, in the manner of a ring, and may be semi-circular, or
of any other convenient figure in its section; and upon this last, the said plate

page_text: and segments form a covering, everywhere closely fitting, and adapted upon the
faces O and S, excepting that space occupied by the springs or screws L, L,
as before mentioned. I represents a shaft in the centre of the whole machi-
nery, upon which is fastened a plate or coupling, Z, Z, having a bar or
radius F proceeding therefrom of any given breadth, but in depth not more
than will allow of its moving with freedom in the interval between the faces
at O and E. To this bar or radius is attached a roller or wheel G, shewn
Figure 3rd by a perpendicular section on a large scale, and the relative situa-
tion of the said roller is such that it precedes the bar or radius when this last
is moved, and that its upper surface shall be so much higher than the upper
surface of the said radius that the roller shall press against the before mentioned
segments in succession, and raise and support them, in order to permit the passage
of the said radius beneath them in succession, and afterwards permit them seve-
rally to descend again into their places. And to the end that the said action
of raising shall be made easy and gradual, a portion of the lower face of each
of the said segments (as shewn in the path H, H, Figure 1st) is rounded or
rendered circularly convex, in the manner delineated at H and Pin Figure 3.
Another roller may also (if thought needful) be attached to the bar or radius
behind it to lower down the segments; in the same gradual manner as they
were raised by the first roller G. The groove D, E (see Figure 2) is in fact a
recess in the deeper groove C, D, and may, if necessary, be filled with hemp and
tallow, or any other materials which may answer the purpose of a packing or
stuffing. R is a piston fitted and revolving in the chamber Y, Y, and also
connected with the bar or radius F; and Q. is a door or valve; which.completely
intercepts the passage of the said chamber, but is capable of being moved out
of the way of the piston by a motion on the strait side thereof, and can be
then lodged in a cell in the face of A, A. And the said piston R is of such a
length at the part nearest the arbor or axis I, and is so disposed in its situation
that the depression of any of the segments herein-before described, by means of
the wheel or roller G, and the passage of the bar or radius F, over such segment
shall be made and completed, and the segment again restored to its first
situation, before any communication can possibly be thereby made between
the internal space Y behind the piston and the external air
And the manner of operation by, and with the said Samuel Clegg's said
Invention is described as follows
Let the piston R be placed in any situation at a distance from the close
door or valve Q, as. for example in the figure, and an elastic fluid introduced
by an aperture near Q into the space Y, on the side T, between the piston and

page_text: the said door or valve. The piston will recede from the elastic pressure and
be carried towards Q, through the space V, out of which last space the common
air will pass off. through the opening at L, L; and during this movement the
segments being in fair bearing everywhere upon 0 (except when raised by the
roller G), will keep the space T, T, T, tight and well closed. But as soon as
the piston arrives at Q, it will push the valve or door out of the way and pass
onwards, the communication of elastic fluid being at this period, and until the
piston hath passed, and the valve again descended out of, and the motion of
the piston kept up by a fly or other well known means, and after the piston
hath passed then the said door or the valve will descend, and the pressure will
continue to operate as before the former elastic fluid passed off through tho
space at L, L. And in case it shall or may be thought fit to introduce steam
as the elastic fluid, and to produce a vacuum in the space towards which the
piston is advancing, the same may be done by a condenser, by injection com-
municating with L, L, the alterations and requisite processor being made by
gear and apparatus; but the said Samuel Clegg makes no claim to the invention
of the rotatary engine, and the parts and combinations thereof, except as herein
described and set forth.
And lastly, the said Samuel Clegg declares that his said Invention is
applicable-to-the.communication of mechanic force, by means of its arbor or
axis, if a ponderous non-elastic fluid, such as water,-be-introduced under the
pressure of an head or column of the same, instead of the elastic fluid herein-
before mentioned or referred to.
In witness whereof, the said Samuel Clegg hath hereunto set his hand
and seal, the Twenty-second day of August, in the forty-ninth year
of the reign of our Sovereign Lord George the Third, by the Grace of
God of the United Kingdom of Great Britain and Ireland King,
Defender of the Faith, and in the year of our Lord One thousand
eight hundred and nine.

page_text: AND BE IT REMEMBERED, that on the same Twenty-second day of
August, in the year above mentioned, the aforesaid Samuel Clegg came beforo
our Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained, in form above written.
And also the Specification aforesaid was stamped according to the tenor of the
Statute in that case made and provided.
Inrolled the same Twenty-second day of August, in the year above
written.