Improvements in Rotary Engines.
Year: 1889

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by PAUL EDMOND DOU and Marie Joseph Auguste Dou,
of Bordeaux, in the Republic of France, Engineers.]
Improvements in Rotary Engines.
I, HENRY HARINGTON LEIGH, Fel. Inst. P.A., Assoc. M. Inst. C.E., practising as
Phillips & Leigh, of No. 22, Southampton Buildings, Chancery Lane, W.C., in the
County of Middlesex, Engineer and Patent Agent, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and-by the following statement :—
This invention relates to improvements in rotary engines actuated by an expansive
or non-expansive fluid.
In order that that my invention, and the means by which the same is to be
carried into practical effect may be thoroughly understood, I will now describe them in
detail, referring in so doing to the accompanying figures which are to be taken as
part of this specification and read therewith.
Fig. 1 is a diagram illustrating the essential principle of the invention.
Fig. 2 is a plan of an engine constructed according to the invention.
Fig. 3 is a section taken on the line X Y of Fig. 1.
Fig. 4 is a section taken on the line V Z of the same figure.
If we take a curve A N B M (Fig. 1) described by the extremities of a right
line A B, of a constant length, compelled to pass through a fixed point. O, of all
the segments defined on one side or the other by the line A B. there is one. A M. B.
whose area is the maximum for a given position of the said line, while the other, A NB,
is the minimum.
Then if the right line A B (or A' B¹) represents the diameter-plan of a piston
revolving within a cylinder A N B M, and the points A and correspond to ports
in communication with fluids of different pressures respectively, the piston will
begin to revolve, and will continue its motion through an angle of 180°, that is
to say, until the points A and B have changed places. The motion of revolution
will then be continued and for the same reason.
Besides the advantages common to rotary engines in general, the present engine
has the property of allowing of expansion without a valve or its equivalent.
Referring to Figs. 2, 3 and 4, A is the cylinder. It is bored out according to
the curve referred to above. B is the piston shaft. There is a mortice C, cut
therein through as much of the shaft as is contained within the cylinder, to receive
the piston D. The latter, of the form of a right parallelopiped with a rectangular
hase, is furnished at each of its extremities with a slider E suitably connected to the
piston, and held in fluid-tight contact with the cylinder by any convenient device
(spring or otherwise). F, F" are the stuffing boxes about the shaft B. G is a
packing adapted to prevent any accidental communication between H, the supply,
and I, the exhaust. The exhaust ports may be of any suitable forin. That illustrated
appears to me to be preferable because of its strength.
Two stuffing boxes are illustrated, but one may be dispensed with if the shaft
be shortened, and the bearing made with a blind end.
The engine works as follows: Each time that the piston passes the supply port,
the latter becomes closed as to the volume of fluid already admitted, which then
expands from the minimum to the maximum. While this is taking place, the
supply, being changed, operates with full effect upon the opposite side of the
piston, expanding the while up to the moment that the supply is cut off, and
so on.
It is clear that the engine may be worked by hydraulic pressure without departing
from the scope of the invention.

page_text: Having now particularly described and ascertained the nature of this said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
In rotary engines, a cylinder bored out to a closed symettrical curve generated
by the extremities of a right line of constant length compelled to pass through a
point eccentric to the symmetrical axis so as to describe during a revolution a
maximum and a minimum segment, in combination with a parallelopipedal piston
adapted to exactly follow the path of the said right line the generatrix of the said
symmetrical curve.
AL
1000
HENRY H. LEIGH.