Year: 1888

page_text: Date of Application, 18th Sept., 1888
Specification Accepted, 26th Oct.. 1888
I JAMES CLARK ROBERTSON, of Morrisdale Mines, Clearfield County, State of
Pennsylvania United States of America, Miner, 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 :-
My invention relates to an improvement in rotary engines and it consists in the
peculiar construction and combination of devices that will be more fully set forth
hereinafter and particularly pointed out in the claims.
In the drawings, Fig. 1 is a vertical longitudinal sectional view of a rotary engine
embodying my improvements. Fig. 2 is a vertical transverse sectional view of the
same. Fig. 3 is a horizontal longitudinal section taken on the line y y of Fig. 1.
A represents a cylindrical case, which is provided with removable heads B which
are secured thereto by means of bolts C. The said cylinder is supported on a bed-
plate, D, and secured to the said bed-plate on opposite sides of the said cylindrical
case and in line with the center of the same is a pair of vertical standards E. In one
side of the cylindrical case A is made a rectangular opening F which communicates
with the interior of the case and in the bottom of the case, on opposite sides thereof
are vertical openings G. H represents a channel which extends from the lower side
of the openings F to the openings G.
Journaled in the upper ends of the standards E is a shaft, I, which extends through
the center of the cylindrical case. Keyed to the center of this shaft and arranged in
the cylindrical case between the openings G is a circular rotary piston K which is
provided with a peripheral groove L.
In one side of the circular piston is an offset or abutment M, the face of which is
flush with the periphery of the rotary piston and one side of said abutment is inclined
as at N, and extends to the bottom of the groove L.
The opposite side of the abutment is curved as at O and also extends to the bottom
of the groove. The said curved portion O of the abutment is provided with an
opening P which communicates with the groove L. In opposite sides of the circular
piston are openings R which communicate with the opening P and are arranged at
right angles to each other as shown.

page_text: The outer ends of the said openings communicate with the spaces in the cylinder A
between the rotary piston and the heads of the cylinder.
S represents a pair of fly-wheels which are keyed to the shaft I on opposite sides of
the cylindrical case and a suitable pulley T is also secured to the said shaft.
U represents a semicircular box or case the inner edges of which extend through
the opening F of case A and are concentric with and bear upon the peripheral flanges
of the circular piston which form sides of the groove L. This box or case U is provided
on opposite sides with curved flanges V, which bear upon and are countersunk in the
case A on opposite sides of opening F, and bolts W are passed through said flanges
and engage with threaded openings in the case A thereby securing the case U to the
case A, as shown. The inner side of the case U has its lower portion covered, as at X,
an opening Y being formed in the upper portion of the inner sides of the case U, the
said opening communicating with the peripheral groove of the rotary piston and also
communicating with the interior of the case.
In the lower side of the said case U is an opening Z which communicates with the
channel H, and in the outer side of the case U is an inlet opening A' through which
the steam water or gas pipe is secured.
B¹ represents a rectangular valve which is arranged in the valve case U and is.
pivoted between the side boards thereof at the center of the case and at a point near
the center of the valve. One end of the valve bears snugly against the circular side
of the valve case, the said valve being pivoted concentrically in the valve case and the
side edges of the valve bear snugly against the opposing edges of the valve case.
The outer end of the valve which is arranged in the opening Y is somewhat longer
than the inner end thereof which bears against the sides of the valve case.
The operation of my invention is as follows :-The engine is at its initial position
when the longer end of the valve bears against the inclined sides N of the abutment
or shoulder M of the circular piston the shorter end of the valve being thereby arranged
between the inlet opening A' and the opening Z of the valve-case so as to cut off
communication between the said openings. When steam water under pressure, com-
pressed air or any other suitable fluid is admitted through the opening A¹, its pressure
on the valve B¹, causes the outer end of the latter to bear against the bottom of the
peripheral groove in the circular wheel with sufficient force to effect a steam tight
joint therewith.
This pressure is prevented from being too great by reason of the inner end or shorter
portion of the valve, the pressure on which partially counterbalances the pressure on
the longer portion of the valve. The fluid pressure is exerted against the abutment
on shoulder M of the circular piston and the fluid travels in the peripheral groove of
the piston and maintains its pressure against the abutment or shoulder thereby causing
the piston to rotate as will be very readily understood. As the piston nears its initial
position, the curved face O of the abutment raises the longer end of the valve from
the bottom of the peripheral groove, thereby uncovering the opening P and putting the
same in communication with the peripheral groove when the dead steam or exhausted
fluid instantly rushes through the openings R in the sides of the rotary piston into the
spaces in the cylindrical case and exhausts through the openings G. As the longer
end of the pivoted valve travels over the curved cam face of the shoulder or abutment,
the opening Y of the valve case is closed thereby so as to cut off the supply of live
fluid to the engine while the abutment M is passing the opening Y. The function of
the opening Z in the valve case and of the channel H in the cylindrical case A is to
permit water resulting from the condensation of steam to escape from the valve
case.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. The combination in a rotary engine, of the cylindrical case A, having the exhaust
openings G, the rotary piston journaled in the case A, arranged between the
exhaust openings and having the peripheral groove, the shoulder or abutment M,
having the cam faces N O, extending in opposite directions the latter being provided

page_text: with the opening P and the said rotary piston being provided with the openings R
communicating with the opening P, the valve case to which fluid pressure is introduced
and the valve pivoted in the valve case and bearing in the peripheral groove of the
rotary piston, substantially as described.
2. The combination of the circular case A, having the exhaust openings G and the
channel H communicating therewith the rotary piston journaled in case A and having
the peripheral groove, the shoulder or abutment M, with the cam faces NO extending
in opposite directions, the latter having the opening P and the rotary piston being
vertically divided with the openings R communicating with the opening P the circular
valve-case secured to the case A, and having the opening Y on the face of the piston,
the inlet opening A¹ and the opening Z communicating with channel H and the
valve B₁ pivoted in the valve case near its center, the shorter end of said valve bearing
against the inner side of the valve case, and the outer end thereof being adapted to
bear in the bottom of the peripheral groove, substantially as described.
Dated this 10th of Santamhan 1000
BERNHARD DUKES,
226, High Holborn, London, W.C.,
Agent for the Applicant.