Year: 1895

page_text: wwwww
GEORGE PAYNE GRACE 160, The Grove Camberwell S.E. Inventor, do hereby
declare the nature of this invention to be as follows:-
Figure 1. of the drawings represents the engine described below with the front
half of the cover off, showing in position, the inner wheel C. with the piston A. &
cams B & B fixed on a small part of its rim U, and the steam & exhaust
ports S. & E. And also showing a section of the partition valve D. shut & the
reversing valve R. T. G. V. in section.
Figure 2. represents a vertical cross section of Fig. 1. with the front half of the
cover on.
Figure 3. represents the engine with the front half cover off, showing the
piston A. & cains B & B¹ covering both the steam & exhaust ports S. & E. & the
groove for the partition valve D. With the partition valve D. open & drawn in
section, with the middle rod f. to operate it from outside. And also showing the
reversing valve R. T. G. V. in elevation, and the relative position & form of
the outside cams I. & I' by the thick dotted lines.
Figure 4. represents a vertical cross section of Fig. 3. with the front cover on,
& with the fly wheels Z & Z¹ & grooved cams I. & I' & fixed guides Q. outside
in section & elevation.
Figures 5 & 6. represent the steam & exhaust ports S. & E. with the extended
parts, & v, and the piston A. & cams B. & B¹ on a larger scale.
The above rotary engine consists of an annular hollow cylinder F. F. in the
accompanying drawings, formed by two similar halves or covers L. L. with a
semicircular depression F. round the inner side of each, and bolted together by
their outer rims or flanges Y. In and round the above annular cylinder a single
piston A. is free to move steam tight, being fixed on the outer rim of a narrow
wheel C. fitted between the above mentioned halves L. of the cylinder and
rigidly fixed on a shaft or pivot J. which turns steam tight in bearings X.
fixed in each half of the cylinder covers L. one each side, & centrally with regard
to the above annular cylinder F. The shaft or pivot J. acting as a driving shaft,
or to turn the fly wheel Z.
The above annular cylinder F. is partitioned off by a single vertical movable
plate or valve D. capable of being lifted up into the enclosed space K. for the
passage under it of the above mentioned piston A. in its motion round the
cylinder F. The above partition plate or valve D. being lifted by means of
the wedgelike action underneath it of a curved surface or cam B. B. of the form
shown in Figures 1. 3 & 5. at the front or forward part of the above mentioned
piston A. and its motion downwards afterwards to partition the cylinder F.
regulated by a similar curved surface or cam B' B' at the back or after part of
the piston A.
The annular cylinder F. having a circular cross section, the cam surfaces B & B¹
to be continued so as to project a short distance beyond the top of the piston A.
to form a flat face at the tops of the cams B & B₁ for the base of the partition
valve D. to slide on instead of the curved side or top of the cylinder piston A.
The annular cylinder F. having a groove g. with a rectangular section formed
round it inside, as a steam tight guide for the above mentioned projecting part.
of the cams B. & B' to move in (Figs. 1. 3 & 5.).

page_text: The pressure of steam on the above piston A. is the power that lifts the above
partition valve D, in ascending to let the piston A. pass under it, the exhaust
port E. being open & the steam from the open steam port S. is prevented from
escaping to the exhaust, as the front cam surface B. is pressed along the lower edge
of the partition valve D. by the motion of the piston A. and consequently there
is a pressure on the piston A. to move it forward till the exhaust port E. is closed.
In ascending the partition valve D. has steam under it from the steam port S.
& also above it from the steam pipe St. through a pipe O. O. leading direct
from the boiler side of the steam supply cock (m) to the top of the partition
valve space K. so that the force required to lift the partition valve D has only to
lift the weight & friction of the partition valve D.
In descending the pressure of the steam is on top of the partition valve D.
its bottom side being open to the exhaust, which makes its descent more rapid, &
also keeps it pressed steam tight along its lower edge against the above mentioned
cam surfaces B' behind the piston A. & thus prevents the steam from the steam
port S. from passing under the valve I). to the exhaust port E. The pressure of
the steam on the top of the partition valve D. when descending also helps to propel
the piston A.
A spring Y Y. with screw adjustment to move it up & down is fitted in the top
of the partition valve space K. to prevent the partition valve D., when at the end
of its motion upwards from leaving the cam faces B. & striking the top of the
steam space K. when lifted very rapidly.
The steam ports S. & the exhaust port E both to be placed near together on
the side of the cylinder with the partition valve D. & its seat between them &
each to be extended to the adjacent corners between the partition valve D. & the
above mentioned groove g. by a small groove or steamway v & v¹ made inside the
cylinder so as to bring the ports S. & E. near to the top of the partition valve D.
& as close together as possible. And both steam & exhaust ports S & E. &
their extensions v. & v¹ to be in such a relative position that the cylindrical sides
of the piston A. & cams B. & B₁ can just fully close & isolate both ports &
the groove for the partition valve D. one from the other steam tight at the same
time, as shown in Figs. 3 & 6. In order to prevent back pressure from com-
pression, & to keep the exhaust port E. open & the steam pressure on for one
revolution as long as possible, & also to open the steam port S. to let the steam
pressure on for another revolution as soon as possible, after the exhaust port is
shut for one revolution & to open the exhaust port E. for another revolution as
soon as possible after the steam port S. is shut for one revolution, by the motion
of the piston & cams round the cylinder.
Both sides of the rim U. of the above described wheel C. on a small portion of
which the piston A. together with the cam surfaces B. & B' is fixed to have
faces U. U. to fit & move close & flat and as near as possible steam tight between
faces U U round the inner side of each half cover L, described above, and near
to the inner part of the annular cylinder F. Any little escape of steam passing
to a covered space N. N. between the covers L. both sides of the wheel C. and
out by the pipe P. to the exhaust pipe Ex. without affecting the motion of the
piston A.
The above described cam surfaces B & B at the front & back of the piston A.
to lift the partition valve D. & regulate its descent being formed both alike, they
will act the same whichever way the piston A. moves in the cylinder F. round the
central shaft J. so that by letting the stean in at the exhaust port E. and out by
the steam port S. the motion of the piston A. on its shaft or pivot J. can be
reversed. And that can be done by the action of the four connected pipes &
cocks T. T. Figures 1. & 3. as the motion together of the handle R. & the four
similar levers G. connected to it & the four cocks T. by the vertical link V. opens
the steam pipe St. to either port S or E. and shuts it to the other port, & at the
same time opens the exhaust pipe Ex., to the other port & shuts it to the steam
pipe St.

page_text: It can be seen from the drawings Fig. 1. 3. & 5. that the steam pressure propels
the piston A. with the exhaust port E. open, from b. round the cylinders to point a.
and is off from a. to b. only once every revolution, and the space a. b. & also the
space c. d. can be reduced by having the came surfaces B. & B1 to the piston A.
steeper & closer together & the ports also closer together & farther from the central
shaft or pivot J. And the steam propels the piston round the cylinders from d to c.
unvaried in power with the maximum pressure for the full sectional are of the
piston & cylinder. The centrifugal force of the wheel C. & piston & cams together
with the fly wheel Z. doing the work for the space a. b, as with the space, near the
two dead points in the crank motion of the ordinary single cylinder engine-
The
fly wheel Z. having a weight W. fixed on it to balance the weight of the piston &
cams round its shaft J.
When convenient two or more of the above rotary engines with the partition
valves in a line on top can be fitted on the same driving shatt or pivot J. with the
piston & cams of each fixel and balanced at different positions equidistant round
it, so as to regulate the motion of the piston A. & cains without a fly wheel, as
the pressure of the steam would then be cut off from one piston only at the same
time.
When convenient the above partition valve D. can also be opened for the
passage under it of the piston A. & shut afterwards from outside the cylinder;
by the assistance of grooved cams I. & 1 similar in form & angular position on
the shaft J. and the same distance from the centre as shown by the thick dotted
lines in Fig. 3. of the accompanying drawings to the cams B & B on the piston A.
inside described above but fitted on two fly wheels Z. & Z' fixed outside one each
side of the cylinder_covers L. on the same shaft J, & connected with & working
the partition valve D. through the top of the valve space K. by three rods f
and cross piece II. together having a backward & forward motion in fixed guides Q.
from a friction wheel or projection e. fixed on each outside rod f. & fitting into
the grooved cams I & I on the wheels Z. & Z¹ Fig. 4. With the above outside
operation of the partition valve D. the piston A. to have cam surfaces B & B¹
back & front the same as those described above for inside operation of the
valve D. with the same object, viz. to enclose the steam between the valve D. &
the cams B or B₁ as described above. And the pressure of the steam above &
below the valve D. are the same as with inside operation of the valve D.
also the position & action of the steam & exhaust ports I. & E. and the above
described pipes O. & P. to the steam & exhaust, and the reversing action of the
valve R. T. V. G. described above are the same.
And
The pressure of the steam being on one side only of the partition valve D. the
above described rotary engine requires to have its framework M, to which it is
fixed screwed to the basement sufficiently strongly to prevent it tipping with a force
equal to the backward & forward thi ust pressure on the ends of the ordinary
horizontal steam cylinders.
The relative pressure of steam above and below the partition valve D. when
opening & shutting and also inside the cylinder of the above describel rotary engine
are as follows.
WITH VALVE D. ASCENDING.
With steam on :-)
--Boiler pressure on top & underneath valve D. & forward motion
of piston with boiler pressure at back only.
With steam off: -Boiler pressure on top with expansion to exhaustion pressure
underneath the valve D. With forward motion of piston & boiler pressure off
back & front.
With steam reversed-Boiler pressure on top & underneath valve D. With
motion of piston reversed & boiler pressure at back of piston only.
With steam half off & exhaust half on :-Boiler pressure on top & less pressure
underneath valve D
With tormand
J
3

page_text: With steam three quarters off & exhaust three quarters on:-Boiler pressure on
top & less pressure underneath valve D. With forward motion of piston & increased
back pressure & reduced forward pressure.
With steam fully reversed in motion-:-Boiler pressure on top & exhaust pressure
underneath valve D. With forward motion of piston & boiler pressure against
mɔtion.
underneath valve D. With forward motion of piston & boiler pressure agamst
mɔtion.
WITH THE PARTITION VALVE D. DESCENDING.
With steam on:-Boiler pressure on top, & exhaust pressure underneath
valve D. With forward motion of piston, same as with the partition valve D.
ascending.
With steam off:-Boiler pressure on top, & exhaust pressure underneath
valve D.
Steam reversed & motion of piston reversed :-Boiler pressure on top & exhaust
pressure underneath valve D.
With steam half off & exhaust half on :-Boiler pressure on top with pressure
underneath less than on top of valve D.
With steam three quarters off & exhaust three quarters on:— -Boiler pressure on
top with pressure underneath less than on top of valve D.
Steam reversed with forward motion of piston :---Boiler pressure on top & boiler
pressure underneath valve D.
=
With an area of piston the same & the length of crank & leverage round the
pivot J. the same say 1., as the leverage of the ordinary crank varies from 1. to 0. in
every quarter revolution its average leverage is just 635 say th while the leverage
of the above described rotary engine is 1. reduced to an average half power only in
the space c. d. Figs. 1 & 5. viz. for about th revolution passed over from starting to
open to fully shutting the partition valve D., which gives an average leverage of 1.
minus . of th revolution, and equals an average leverage of ths as compared with
ths given above as the leverage of an ordinary crank motion. Consequently the
power of the above described rotary engine is 1½ times greater from leverage only
than an ordinary reciprocating engine with the same area of piston & length of crank
or leverage round the central pivot J. besides the power gained from greatly reduced
inertia of oscillating parts. But as the length of crank or leverage round the
centre of the above rotary engine drawn being fixed on the rim of the large wheel C.
is about 3 times as long as the customary length of crank in the ordinary engines
with the same area of piston, therefore the engine drawn is about 3 times 1. viz.
5 times as powerful as an ordinary reciprocating engine with the same area of
piston & the same number of revolutions per minute, and the steam used per
revolution about 5 times as much at the same pressure.
Dated May 18th 1805
GEO. PAYNE GRACE.
GEORGE PAYNE GRACE 160, The Grove Camberwell, S.E. Inventor, 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 :-
The above rotary engine consists of an annular hollow cylinder F. with a circular
cross or transverse section formed by two similar halves or covers L. bolted
together by their outer flanges, with a semicircular depression formed round the
inner side of each at a considerable distance from their centre, & each half
cover L also having a depression round it inside between the depressions to form

page_text: the cylinder F. & the centre of each, in order to form a covered chest or space N.
between them (Figs. 1. 2. 3. 4). In and round the above mentioned annular
cylinder F, a piston A with a cam surface B. & B' fixed at the back & front of it
as described below, is free to move steam tight being fixed on a small part of the
outer rim U. of a narrow wheel C. of considerable diameter free to turn in the
covered chest N., its rim U. fitting as near as possible steam tight in a narrow
groove U all round & through the middle of the inner part of the annular
cylinder F. & rigidly fixed o. an axle or shaft J. which turns steam tight in
bearings X. fixed in each half of the cylinder coveis L, one each side centrally
with regard to the above mentioned annular cylinder F. The shaft or pivot J.
acting as a driving shaft or to turn a fly wheel Z. fixed on it.
The above mentioned annular cylinder F. is partitioned off by a movable plate
or valve D. D. (Figs. 1. 2. 3 & 4) in the drawings, of a rectangular form fitting
steam tight in grooves, one each side of the cylinder F. and capable of being
freely lifted up steam tight into an enclosed steam space K. K. fixed on the annular
cylinder F., for the passage by or under it of the above mentioned piston A.
& cams B. & B¹ in their motion round the cylinder F. The above mentioned
partition plate or valve D. being lifted or opened by means of the wedgelike
action underneath or against it, of a curved surface or cam B. B. of the form shown
in (Figs. 1. 3 & 5) of the drawings, as broad as the cylinder F. with cylindrical
sides fitting close to the cylinder & fixed at the front or forward part of the above
piston A. and its motion afterwards to close or part the cylinder F, regulated by a
similar curved surface or cam B' B', also as broad as the cylinder F fixed at the
back or after part of the piston A. Both the cams B. & B' together with the
piston A. to be fixed on only about a fifth part of the circumference of the inner
wheel C., or with the extent of their bases equal to about twice their height, to
keep the partition valve D. fully down or shut, so as to maintain the maximum
effective area & power of the piston A. unvaried, for nearly a complete revolution
of the piston A. And the two parallel edges of the base or inner end of the
above mentioned rectangular partition plate or valve D. to be rounded so as not
to scrape the surfaces of the above mentioned curved cams B. & B¹ when sliding up
or down them.
The annular cylinder F. having a circular cross section (Figs. 1 & 2) the cam
surfaces B & B are continued so as to project a short distance beyond the top of
the piston A. to form a flat face at the tops of the cams B & B for the base of the
partition valve D. to slide on instead of the curved side of the circular piston A.
The annular cylinder F. having a groove (g.) with a rectangular section formed
round it inside, as a steam tight guide for the above mentioned projecting part
of the cams B & B to move in Figs. 1. 5 & 6.
The pressure of the steam on the back of the piston A. & cams is majorly the
power that lifts the partition plate or valve D. in ascending or opening to
let the piston A. pass by or under it. The exhaust port E. being open in front of
the piston till the valve D is fully up & the steam from the open steam port S. is
prevented from escaping under the partition valve to the exhaust, as the front cam
surface B. being as broad as the cylinder F. is pressed steam tight under & along
the lower or inner edge of the valve D. by the steam pressure at the back of the
piston A. moving the cam B forward & opening the valve D. with the assistance
of the fly wheel when almost fully open, Figs. 1. 5 & 6. Also in ascending or
opening the partition valve D. has steam under its base or inuer end from the
open steam port S. & also on top of it from the steam pipe St. through a pipe O. O.
leading direct from the boiler side of the steam supply cock (m) to the top of the
partition valve space K. K. consequently the force required to lift or open the
valve D. has only to overcome the weight & friction of the valve D.
In descending or shutting the full pressure of the steam is continuously on top
of the partition valve D. from the steam pipe O. O. its base or inner side being
open to the exhaust port E., which makes its descent or shutting more rapid
& also keeps it pressed steam tight along its inner edge against the above

page_text: the
mentioned cam surface B' behind the piston A. & thus prevents
steam from the steam port S. from passing between the valve 1. & the cam
surface B' to the exhaust port E. The pressure of the steam on top of the
partition valve D. when shutting also helps to propel the piston A.
A spring y. y. with a screw adjustment t move it up & down is fitted in the
top of the partition valve space K. (Fig. 1) to prevent the partition valve D. when
at the end of its motion upward in opening from leaving the cams B & B', &
striking the top of the steain space K. when opened very rapidly. The spring y.
also helps to shut the valve D.
The steam purt S. & the exhaust port E (Figs. 1. 3. 5. of the drawings) are
both to be placed on either side of the cylinder F. near together with the partition
valve or plate D & its sent between them, & each divided from the partition
valve D. by flanges level with the cylinder, & so that the cylindrical side of the
piston A. together with the cylindrical sides of the cams B. & B¹, will just fully
cover, & close the whole of both the steam & the exhaust ports S. & E. & v. & v¹,
& the groove for the valve D. at the same time, & also isolate them steam tight
one from the other, in order to prevent waste of steam. And near to the outer
end of the partition valve D. each steam & exhaust port S. & E. to be extended
by a small groove or steamway & ¹, made in the cylinder F. & divided from the
groove for the partition valve D., & leading from the port to the extreme corner in
the cylinder close to its adjacent side of the groove of the partition valve D.
In order to prevent back pressure from compression, & to keep the exhaust port E.
open as long as possible, & also to open the steam port S. as soon after as
possible & to open the exhaust port as soon as possible after the steam port is shut,
by the motion of the piston & cams A. & B. B₁ once every revolution of the
piston.
Both sides of the narrow rim U. of the above mentioned inner wheel C. on which
the piston A. is fixed to have faces U. U. made to fit & move close & flat & as
near as possible steam tight between faces U₁ & U¹ round the mner side of each
halt cover L. described above, near to the inner part of the annular cylinder F,
which together form an open groove U₁ U₁ound the middle of the inner side of
the cylinder F. in which the nanow rim U. of the inner wheel C. travels, and
closes continuously as near as possible steam tight. Any little escape of steam
passing to the covered chest or space N. between the covers L. both sides of the
wheel C. between its bearing rim U.. its shaft J. and out by a pipe P. to the
exhaust pipe Ex. without affecting the motion of the piston A. As the exhaust
chest or space N. takes the steam pressure off a large area at the middle part of the
cylinder covers L. the distance of the piston from the axle J. can be much increased
with very little increase of danger from bursting.
LV
The above described cam surfaces B & B at the front and back of the piston A.
to open the valve D. & regulate its shutting being formed both alike they will act
the same which ever way the piston A. moves in the cylinder F. round the central
shaft J. So that by letting the steam in at the exhaust port E. & out by the
steam port S. the motion of the piston A. & its shaft J. can be reversed.
And that ca. Le dor ely the action of the four connected steam cocks t. (Fig. 1.)
as the motion together of the handle R & the four similar levers q connected to it
& the four cocks t. by the vertical link ., opens the steam pipe St. to either
port S. or E. & shuts it to the other port, & at the same time opens the exhaust
pipe Ex. to the other port & shuts it to the steam pipe St.
It can be seen from (Figs. 1. 3. 5.) that the team pressure propels the piston A.
& cams B & B with the exhaust port E. open, from dotted line b. round the
cylinder to the dotted line a, & 14 iully off from a. to 6 only once every revolution
of the piston. And the stean propels the piston round the cylinder from dotted
line d to dotted line c. with the unvaried maximum pressure for the full sectional
area of the piston & cylinder F.
The angular space c. to d. can be reduced by having the cams B & B steeper &
closer together, & the ports S. & E. also closer together, & by having the annular

page_text: cylinder F. farther from the central shaft J. The centrifugal force of the wheel C.
& piston A. & cams B. & B¹ together with the fly wheel Z. doing the work for
the instant of motion (from a. to b.) as with the spaces near the two dead points in
the crank motion of the ordinary single cylinder engines. The fly wheel Z. having
a weight W. fixed on it to counterbalance the weight of the piston & cams round
the shaft .J.
When convenient two or more of the above rotary engines can be fitted on the
same driving shaft J. with the piston A & cams B of each fixed and balanced at
different positions, equidistant round it, so as to regulate the motion of the
piston A. without a fly wheel, as the pressure of the steam woull then be cut off
from one piston only at the same time, the partition valve D. & chamber K. of each
cylinder being fitted so as to be in the same line with each other over the
shaft J.
When convenient the above described rotary engine can have a con lenser fittel
on for the exhaust steam, or a suitable cut off arrangement might be fitted for using
the steam expansively.
With the pistons & cams fitted on their shaft J. so as to open & shut the vertical
partition valves at the same time the above described rotary engine might be
arranged as a compound expansion rotary engine with cylinders of different size..
The exhaust steam from the smallest passing through its exhaust port to the steam
port of a larger cylinder for work expansively, & if convenient the expandel
steam from the larger cylinder can pass through its exhaust port to the steam
port of a still larger cylinder for farther expansion & work, and then out to a
condenser.
When shut the partition valve D. apart from gravity pressure is kept tight in
its seat by the steam pressure in the valve chamber K. as there is exhaust steam
pressure one side only of its base inside & full pressure on the other side of its
base inside the cylinder F., so that the pressure underneath between its base, & its
Beat is a mean between the pressure of the exhaust & full pressure, & therefore less
than the pressure on top of it.
And to prevent friction & heating the base of valve D. can be so fitted in its
seat that when shut it cannot be pressed against the circumference of the inner
wheel C. by the steam pressure on top of it.
And the pressure on the base of the partition valve D. when opening can be
reduced by rounding or bevelling off the edge of the base that is in contact with
the front cam surface B., which reduces the area of the base to the steam pressure
upwards & consequently increases the power required to open it, the inner part of
the base nearest the front cam surface B. being open to the exhaust port E. And
in shutting, also the exhaust pressure on the base of the partition valve D. can he
reduced by rounding or bevelling off the other parallel edge in contact with the
back cam surfaces B', which reduces the area of base to the exhaust & decreases
the downward force to shut it, & consequently reduces the speed in shutting, the
inner part of the base nearest the back cam surface B¹ being then open to the steam
pressure upward from the steam port S.
The pressure of steam on the portion of the circumference of the inner wheel C.
that is exposed to the pressure of the steam in the cylinder F. with the exhaust
pressure on the other portion of the circumference can be reduced by making the
rim U. that closes the slot U' U' round the cylinder F. inside, narrower.
The full pressure of the steam being on one side only of the area of the partition
valve D. the above described rotary engine requires to be fixed to the basement
sufficiently strongly to prevent it tipping with a force equal to the full pressure on
the steam port side less the pressure on the exhaust port side.
The above partition valve D. can also be opened for the passage of the piston A.
& shut afterwards from outside (Fig. 3. & 4.) of the drawings, by the assistance of
grooved cams I. similar in size, form, & angular position on the shaft J. to the
cams B & B¹, fixed on the piston A. inside described above, as shown by the thick

page_text: dotted lines in (Fig. 3), but fitted on two small fly wheels Z' fixed outside, one
each side of the cylinder covers L on the same shaft J. & connected with & working
or helping to work the partition valve D. through the top of the valve chamber K.
by three rods f. & a cross piece H, together having backward & forward motion in
fixed guides Q, one each side of the cylinder covers L, from a friction wheel or
projection (e.) fixed on each outside rod f. & fitting into the grooved cams I.
(Fig. 4).
With the above described outside operation of the valve D. the piston A. to
have cam surfaces B & B2, at front & back inside, the same as those described
above for inside operati n of the valve D. with the same object, viz. to enclose the
steam or exhaust space between the valve D. & the cam surfaces B or B' when
opening or shutting as described above. And the pressure of the steam on the
base & on top of the valve D. are the same as with inside operation of the valve D.
And also the position & action of the steam & exhaust ports S. & E. & the above
described steam pipe O. & exhaust pipe P. & the reversing action of the reversing
valve R. t. u. q. are the same.
While the partition valve D. is fully shut the effective working pressure on the
above mentioned piston A. & cams B & B is the same as with an ordinary piston
& cylinder of equal area or cross section, as the oblique pressure, which is reduced
by the steam getting under the base of the cams B. & B', only bears upon the
central axle J. and gives the minimum amount of friction. The centrifugal force
of the piston & cams also tend to counterbalance the thrust pressure on the central
axle J.
With an area of piston the same & the length of crank & leverage round the
axle, the same say I as the leverage of the ordinary crank varies from 1. to 0. in
every quarter revolution, its average leverage is just 0.635 equal say th, while
the leverage of the above described rotary engine is 1. reduced to an average half
power only in the space c. to d (Figs. 1. 3. & 5.) viz. for about one fifth of a
revolution passed over from starting to open to fully shutting the partition valve D.
which gives an average leverage of 1. minus of th of a revolution, and equals
an average leverage of th as compared with oths given above as the leverage of
an ordinary crank motion. Consequently the power of the above described rotary
engine is 1 times greater froin leverage ouly than an ordinary reciprocating engine
with the same area of piston & length of crank or leverage round the central axle,
besides the power gained from greatly reduced inertia of oscillating parts. But as
the length of crank or leverage round the centre axle J. of the above rotary engine
drawn being fixed on the rim of the large wheel C. is about 3rd times as long
as the customary length of crank in the ordinary engines with the same area of
piston, therefore the engine drawn is about 3 times 1 times, viz. 5 times as
powerful as an ordinary reciprocating engine with the same area of piston & the
same number of revolutions per minute, and the steam used per revolution about
5 times as much at the same pressure.
The relative pressure of steam on the base inside and on top of the partition
valve D. when opening & shutting, and also inside the cylinder of the above
described rotary engine is as follows:-
WITH THE PARTITION VALVE D. (PENING.
With steam full on:-Boiler pressure on top & on the base of valve D. With
forward motion of piston & boiler pressure at back only.
With steam shut off -Boiler pressure on top, with expansion to exhaustion
pressure on the base of the valve D. With forward motion of piston, and boiler
pressure off back & front.
With the reversing valve half turned-Boiler pressure on top & less pressure
1
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of niston be momentum &
game

page_text: With the reversing valve turned :-Boiler pressure on top & less pressure on
the base of valve D. With forward motion of piston from momentum, with greater
pressure contrary to motion than pressure forward.
With reversing valve fully reversed & with forward motion of piston from
momentum-Boiler pressure on top & exhaust pressure on the base of valve D.
and with boiler pressure against motion of piston.
With reversing valve fully reversed & motion of piston reversed: -Boiler
pressure on top & on base of valve D. & boiler pressure at back of piston only.
With steam full on :-Boiler pressure on top and exhaust pressure on the base of
valve D. With forward motion, and pressure on piston the same as with the
valve D. opening.
With steam shut off:-Boiler pressure on top & exhaust pressure on the base of
valve D.
With reversing valve half turned :--Boiler pressure on top & pressure on base
less than on top of valve D.
With reversing valve turnel :-Boiler pressure on top with pressure on the
base less than on top of valve D.
momentum.
With reversing valve fully reversed & with forward notion of piston from
Boiler pressure on top & boiler pressure on the base of valve D.
With reversing valve fully reversed & with motion of piston reversed: -Boiler
pressure on top & exhaust pressure on the base of valve D).
To keep the bearing faces U. & U¹ of the rim U. of the inner wheel C. steam
tight after wear rings (Figs. 5 & 6.) can be fitted steam tight round the inner
edge of grooves made round the bearing faces U on the cylinder covers with a
space behind them. A portion 8. of the bearing faces of the rings r. towards the
exhaust space N. being cleared from contact with the face U. of the rim of
the wheel C. or that the steam behind the rings can press them more firmly
against the rim U. of the wheel C. the space S. being more or less open to the
exhaust space N.
The piston between the cams B & B of the above described rotary engine can
be kept steam tight by two stiff broad belts or half rings A. (Figs. 5. & 6.) pressed
out by springs. Both half belts A. being shaped to the form of the cylinder before
fitting. And both half belts being made broader in the middle so as to pass more
freely over the steam & exhaust ports & the groove for the partition valve.
(Figs. 5. & 6.)
When the piston is fitted with belts A to keep it steam tight as described above
the steam and exhaust ports S. & E. can be made with several divisions across
them level with the form of the cylinder, so as to divide the ports into several
smaller openings communicating with each other from behind, so that the piston &
belts A. can pass more freely over the ports (Figs. 5 & 6.).
The bearing faces of the broad half belts A. can have detached shallow grooves
made across them from side to side apart from their edges for the steam to get into
so as to reduce the force with which they are pressed against the sides of the
cylinder by the steam from behind. (Fig. 5. & 6.)
The exhaust port can be made to open more fully before the valve commences to
descend by making the flat part at the top of the cams 13 & B₁ between w & w¹
of greater extent (Fig. 5.), with the ports placed as described above.
The above described rotary engine will reverse quickest when the reversing
valve is only turned about three quarters of fully reversed as in that case there is
more steam pressure on top of the partition valve D. than there is on the base of
the valve D, both in opening & shutting.
With the coefficient of friction, Z₁ = the angle made between the vertical
face of the partition valve D., & a taugent to the surface of the cam B. at any
point of contact with the base of the partition valve D., and with S = the whole
B

page_text: pressure from the steam on the side of the partition valve less the exhaust pressure
on the other side, then the full pressure vertically upwards on the partition valve,
without friction, from any tangential or forward pressure P. upou it from the
piston & cam B. is as follows:-
:―
1st. In forward motion with the steam pressure S. on the opposite side of the
partition valve to the cam B. the full pressure upwards from P. without friction
P. (tan Zo+utan. Zº)-μ. S.
15=
2nd. In reversing with the steam pressure S. on the side of the partition valve
next to the cam B. the full pressure upwards from P. without friction
15= P. (tan Z-2 μ-µ³ tan Zº)-μS.
=
3rd. With the steam pressure S. the same both sides of the partition valve D.
the full pressure upwards from P. without friction is - P. (tan Zº-2 μ- μ²tan Zº).
The work to be done by the accumulated force of the fly wheel being
about oth the power of the rotary engine drawn for one revolution. And as the
work to be done by the accumulated force of its fly wheel is about 3rd of the full
power of an ordinary single cylinder engine miz. about th power exerted twice every
revolution, consequently the fly wheel for the above described rotary engine need
only be as th compared with th power, viz. about 3rds the power of the fly wheel
for an ordinary single cylinder engine of the same power.
The indicated horse power of the above described rotary engine equals the
average pressure per square inch in pounds, multiplied by the sectional area of the
piston A. in square inches, or by the area of a radial section of the cylinder F. in
square inches, multiplied by twice the distance of the centre of the piston A. in
feet, or the distance in feet of the centre of the cylinder F. from the central axle J.,
multiplied by 3: 1415, multiplied by the number of revolutions of the piston per
minute, and divided by 33,000), and multiplied by about th for the engine drawn.
Figure 1. of the accompanying drawings represents the rotary engine for inside
operation of the partition valve D. without the assistance of grooved cams outside,
with the front half cover off, showing in position the inner wheel C. with the form
of the piston & cams B & B₁ fixed on its rim U. And the steam & exhaust
ports S. & E.
And also showing a section of the partition valve D. shut, and the
reversing valve R. t. u. q. in section.
Figure 2. represents a vertical cross section of Fig. 1. with the front half cover
on, showing the position of the narrow wheel C. enclosed in the exhaust steam
chest N. between the cylinder F. and the central axle J. with its rim U. in the
slot U of the cylinder J.
Figure 3. represents the rotary engine for inside assisted by outside, operation
of the valve D. with the front cover off, the same as Fig. 1. showing the form &
relative position of the outside cams I. with regard to the inside cams B. & B¹ &
the piston A. by the thick dotted lines.
And
Figure 4. represents a vertical section of Fig. 3. with the front cover on.
showing the fly wheels Z. & Z' with the grooved cams 1. and fixed guides Q.
outside in section & elevation, together with a vertical section of the piston A.
Figure 5. represents a front elevation of the steam & exhaust ports S. & E. &
extensions v. & r &c. And the piston & cams B & B¹ on a larger scale.
Figure 6. represents a vertical section of Figure 5. with the piston A. underneath
the lifted partition valve.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is
The above described improved rotary engine with forward or backward motion,
consisting of a uniform & continuous hollow annular cylinder F. with a circular
cross section, & with an exhaust steam chest N. formed between it, & the central
axle J., so that it can be constructed at a considerable distance from the centra
axle J. And having a single movable partition D. fitted inside vertically above
the central axle with steam pressure direct from the boiler side of the steam supply

page_text: The
cock m. on top of it continuously, to partition the cylinder & open for a single
piston, with broad cams B. & B having cylindrical sides or edges & projecting
tops . fixed back & front, to pass under & shut afterwards as described above.
The piston together with the broad cams B. & B₁ being fixed on the narrow
rim U. of an inner wheel C. of considerable diameter, which turns in the above
neutioned exhaust chest N. on & with the central axle J. at its centre.
cams B. & B inside & the grooved cams I. outside being of such a form that
they only subtend small angular distance round the central axle J. as described
above, so as to open the partition valve D. & regulate its shutting afterwards &
leave it unmoved for nearly a complete revolution of the piston as described above.
And with the steam & exhaust ports S & E with the extensions v. & vlas
described above, so placed on the side of the cylinder F. with the partition valve &
its seat between them, that the cylindrical sides of the piston & cains B & B can
just fully shut & isolate from each other both ports & the groove for the partition
valve D. steam tight at the same time as described above.
Dated this 14th day of September 1895.
GEO. PAYNE GRACE.