Improvements in Rotary Steam Engines.
Year: 1899

page_text: Date of Application, 9th May, 1899-Accepted, 4th Nov., 1899
Improvements in Rotary Steam Engines.
I, JAY WOODARD POWERS, of 2306, Dupont Avenue, North Minneapolis, County
cf Hennepin and State of Minnesota, U.S.A., Mechanical Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
My invention relates to steam engines, and especially to a class of engines
wherein the pistons are driven continually in one direction, known as rotary
engines, in contradistinction to those wherein the pistons are driven backward
and forward, known as reciprocatory engines; and the purpose of my invention
is the production of a rotary engine wherein the steam may be used expansively
in the sense that it is conducted to a chamber and allowed to expand therein
and act upon a piston causing the latter to rotate and so drive the engine shaft,
in contradistinction to the common forms of rotary engines wherein steam drives
by direct impact vanes or paddles in a rotating disc.
To this end my invention consists of an outer case or frame, having parallel
heads which form the boxes or bearings for my driving shaft; a pendulum sus-
pended within said outer case or frame; and elliptical chamber within the body
portion of said pendulum; and a cylindrical piston, eccentrically mounted upon
the said shaft and revoluble within the said elliptical chamber; all of which is
clearly shown in the accompanying drawings, and fully described in the following
specifications.
In the drawing, Fig. 1 is a side elevation of my improved engine; Fig. 2 a
section of Fig. 3 taken on the line 3-3, Fig. 3 an end elevation; and Fig. 4 a
section of Fig. 1 taken on the line 44.
Similar letters refer to similar parts throughout the several views, a being the
outer case or frame; b, the heads; c, the shaft; d, the pendulum, and e, the
piston. The outer case or frame a, may be fashioned in any desired form, pro-
vided its heads or covers b, are parallel. It is not essential that it be steam tight
as shown, but may consist of an open frame adapted to hold the steam tight
heads b, and to suspend the pendulum d. The heads are provided with the
steam tight boxes f, the steam pockets g, the supply pipe h, the exhaust pipe i.
the ingress duct j, and the egress duct k.
The boxes serve as bearings for the shaft c. They are rendered steam tight
by means of the stuffing glands 7. The steam pockets 9 are semi-circular recesses
made in the inner faces of the heads b, as shown in dotted lines in Fig. 2. They
partly encircle, and are concentric with the shaft c.
The supply pipe h is tapped into the outer face of one of the heads b, and serves
to admit steam to my engine. The exhaust pipe i is tapped into the outer face
of the opposite head 6, and serves to exhaust steam from my engine. The ingress

page_text: duct leads from the supply pipe to one of the steam pockets g, and the egress
duct leads from the other steam pocket g to the exhaust pipe i.
The shaft c is not unlike those of other engines save that it has no crank
portion. It is rotated within the boxes f by means of the piston e affixed
thereto, as will hereinafter be set forth. Mounted upon this shaft (c) is the
balance wheel m, which tends to render its revolutions uniform, and the band
wheel n, by means of which its power is transmitted in the usual manner.
The pendulum & consists of a shaft portion o, and a body portion p.
portion is pierced near its upper end, is suspended, and oscillates upon the
pivot q. The body portion p is hollow, having the transverse elliptical chamber r
therein, within which the piston e is revolved.
The shaft
The depth of this elliptical chamber (r) is.equal to the length, its width is
equal to the diameter, and its length is equal to twice the "throw" of the cylin-
drical eccentric piston e. This is an important feature of my invention for upon
the configuration of this chamber (7) depends the operation of my engine.
The piston e consists of a cylinder of uniform diameter and with parallel ends.
eccentrically mounted upon and rigidly affixed to the shaft c. Its length is equal
to the depth of the elliptical chamber r, within which it is chambered, and its
"throw" is equal to one half the length of the same. Its parallel ends are
pierced to form the ingress steam port s, communicating with a supply steam
passage leading to its periphery in one direction, and with a similar exit port
communicating with an exhaust steam passage v leading to its periphery in an
opposite direction.
The operation of my engine is as follows: Live steam being admitted to the
supply pipe h, flows through the ingress duct j, and the semi-annular pocket 7,
thence (when in register) into the ingress steam ports of the piston e, thence into
the lower crescent of the elliptical chamber r, where it expands, driving the
niston e upward and around in the direction indicated by the arrow (Fig. 2), to
the upper end of the elliptical chamber r. While the piston e has thus been
impelled by the live steam in the lower end of the elliptical chamber r, the
exhaust steam in its upper end escapes through the exhaust steam passage v, to
the exit port and exit duct k, and the exhaust pipe i.
My engine may be reversed by reversing the steam. That is to say, by admit-
ting the steam thereto through the exhaust pipe i, and exhausting it through the
supply pipe h, which will cause the piston to rotate in a direction opposite to
that indicated by the arrow.
It is apparent that the rotation of the eccentric piston e will oscillate the pen-
dulum d, thereby holding the opposite walls of the elliptical chamber in con-
stant contact therewith that in its rotations it alternately enters, fills and recedes
from opposite ends of the said elliptical chamber r. thereby forming, at each
revolution, two crescent shaped pockets and . wherein the steam exerts its
force expansively, forcing the piston continuously from the interior elliptical
wall.
Having now particularly described and ascertained the nature of this said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a steam engine, the combination of an outer case; an oscillating case
suspended therein; an elliptical chamber within the said oscillating case; a cylin-
drical piston rotatable within said elliptical chamber; said piston being eccen-
trically mounted upon a shaft, and said shaft being supported by, and revoluble
in the heads of the said outer case; said heads having steam pockets, ports and
passages adapted to convey live steam to, and exhaust from, the said elliptical
chamber, substantially as shown and described.
2. In a steam engine, the combination of an outer case or frame; a pendulum
supported by, and oscillatory within, the said outer case or frame; an elliptical
chamber within the said pendulum; a cylindrical piston rotatable within the said

page_text: elliptical chamber, said piston being eccentrically mounted upon, and rigidly
secured to, a shaft, and covers upon the said outer case or frame and enclosing
the said pendulum and piston, and said covers being provided with pockets, ports
and passages adapted to admit live steam to, and to convey exhaust steam from,
the said elliptical chamber, substantially as shown and for the purposes specified.
Dated this 8th dare of Ian 1900
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.