IMPROVEMENTS IN ROTARY ENGINES
Year: 1880

page_text: LETTERS PATENT to Henry Thibalt and Thomas Hawkins, of the City,
County, and State of New York, United States of America, for an Invention
of "IMPROVEMENTS IN ROTARY ENGINES."
PROVISIONAL SPECIFICATION left by the said Henry Thibalt and Thomas
Hawkins at the Office of the Commissioners of Patents on the 5th June 1880.
HENRY THIBALT and THOMAS HAWKINS, of the City, County, and State of
New York, United States of America. "IMPROVEMENTS IN ROTARY ENGINES."
The object of this Invention is to provide a rotary engine which will give much
greater power for the same amount of steam than any other construction of steam-
engine. This engine has no dead points, and combines great simplicity and
cheapness of construction.
In carrying the said Invention into practice, we provide a case which is mounted
or secured on a bed. This case is provided with channels or ports for the passage
of steam. Within the said case revolves a drum connected with or secured to a
shaft. The drum is provided with eight sliding pistons, which slide in receptacles
provided in the drum. These pistons rest on springs, which are for the purpose of
holding the aforesaid pistons in position to take steam, and at the same time to
diminish the shock when these pistons by the revolution of the drum are forced
These
down by contact with the case in the receptacles of the said drum.
receptacles are provided with covers.
The edges of the drum are bevelled to correspond with packing rings, one side of
which is also bevelled. These packing-rings are fitted between the case and drum
for the purpose of packing the joint between said case and drum, thus preventing the
escape of steam and rendering the said joint steam-tight. These packing-rings are
provided on their backs with flat springs to prevent the rings from binding. The
said rings are tightened or loosened and adjusted by means of set-screws, which
work upon the springs at their centre.
Steam is admitted to the engine by means of a feed-pipe which connects with
the steam-chest in communication with the ports of the case. The steam admitted
to these ports by means of the valve connected with the steam-chest, passes thence
into the steam-spaces between the case and drum.

page_text: The drum and case are so arranged in relation to each other as to cause the said
steam-spaces at portions of their circumference to be of such depth as will allow the
pistons to be acted on by the pressure of the steam, and then cause the said steam-
spaces to taper gradually, so that the drum and case nearly touch; an exhaust-pipe
is provided for the passage of the steam after it has exerted its pressure on the
sliding pistons. There are two springs as face-packing for the drum, which springs
are placed between the drum and case for the purpose of preventing the escape of
steam between the drum and the case at the points where said packing is placed.
A lever is provided, connected by a rod with the steam admission valve, for the
purpose of reversing the engine when desired.
There is a guide-band or rim to the drum, which rim or guide-band guides the
pistons in the case.
The steam enters the steam-chest through the feed-pipe, and thence passes into
the ports or channels of the case, and then into the steam-spaces at the same time.
Two of the pistons (one on each side of the drum) are held in position by the
springs ready to take steam, and the steam entering the steam-spaces exerts
pressure on said two pistons at the same time, and thus causes the drum and shaft
to revolve; and the steam thus acting on two opposite sides of the drum at the
same time relieves the shaft from the weight which would be caused by the
pressure of the steam on the face of the drum, were the steam admitted to one side
only of the drum. The pistons as they are carried around the circle by the
revolution of the drum are forced down into the receptacles of the drum as they
pass from the beginning of the inner ports of the case to points at the lower part.
The said pistons, after passing the said points, are forced out into the steam-spaces
(so as to take astean) by means of centrifugal force, aided by the springs. The
steam, after exerting its pressure on the pistons as they pass through the steam-
spaces, passes out of the exhaust-pipe. If it is desired to reverse the engine, the
lever is pulled which acts on the valve, and allows the steam to flow into the
opposite ports and thus reverse the action of the engine.
By having eight pistons instead of four or six, as in ordinary rotary engines, we
secure greater steam space for the same diameter of machine, and the stroke being
one eighth of the circle, instead of one-sixth or one-fourth, reduces the friction and
resistance which the drum would otherwise encounter, and allows the steam-space to
more gradually diminish, and thus have a longer incline than would be the case if
the stroke were one-quarter or one-sixth of the circle. The engine can also be
packed while running at full speed by turning the set-screws on the outside of the
case, which adjust the packing-rings, thereby avoiding all trouble and waste of
time in packing, as is the case in packing other engines.
The construction of the case is such that there is no action of the steam on the
pistons while working in and out of the drum, thereby preventing friction and
ensuring long wear of pistons. The pistons are isolated and separated from each
other in each of their receptacles, so that steam cannot escape from one to the other,
thereby preventing the steam from interfering with the pistons out of action. The
engine as so constructed will also have no dead points, and there is no loss of power
at any point of the revolution of the drum.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Thibalt and Thomas Hawkins in the Great Seal Patent Office
on the 4th December 1880.
HENRY THIBALT and THOMAS HAWKINS, of the City, County, and State of
New York, United States of America. "IMPROVEMENTS IN ROTARY ENGINES."
Our Invention relates to rotary engines, and it consists in certain improvements
therein as hereinafter more fully set forth, and pointed out in the claims.
In the Drawing, Figure 1 represents a cross-section of our improvement on the
line x, x, of Figure 2; Figure 2 represents a vertical section of the same; Figure 3
represents a vertical section on the line y, y, of Figure 2; Figure 4 represents one
of the packing rings.
Our improvements are made as follows:-A case R is mounted or secured on a
bed H. This case R is provided with channels or ports F and F1 for the passage
of steam and with recesses a, a. Within the case R revolves a drum L connected with
and secured to a shaft O. This drum L is provided with end flanges L' bevelled
outwardly, and eight sliding pistons M, which slide in receptacles provided in the
drum L, and which pistons M rest on springs N, which are for the purpose of
holding the pistons M in position to take steam, and at the same time to diminish
the shock when the pistons M, by the revolution of the drum L are forced down
by contact with the case R into the receptacles of said drum L. These receptacles
are covered with the covers P, as shewn in Figure 2.
The flanges L' of the drum L are bevelled, as shewn in Figure 1, to correspond
with the packing-rings S, one side of which is also bevelled. These packing-rings
S are fitted between the case R and flanges L' of the drum L and the recesses a of
the case, for the purpose of packing the joint between said case and drum, thus
preventing the escape of steam, and rendering the said joint steam-tight. These
packing-rings S are provided on their backs with flat springs I (shown in Figure 4)
to prevent the rings from binding. The said rings S are tightened or loosened and
adjusted by means of the set screws J (shown in Figure 1), and which set screws
work upon the springs I at their centre.
Steam is admitted to the engine by means of the feed-pipe A communicating
with the steam-chest B, which is connected with the ports F, F', of the case R.
The steam admitted to these ports F, F¹, by means of the valve C arranged within
the steam-chest B, passes thence into the stean-spaces V between the case R and
drum L.
The drum L and case R are so arranged in relation to each other as to cause the
steam-spaces V, at portions of their circumference, to be of such depth as will allow
the pistons M to be acted on by the pressure of the steam, and then to cause the
said steam-spaces V to taper gradually, so that the drum and case nearly touch, as
shewn in Figure 2.
E represents the exhaust-port for the steam to pass out after it has exerted its
pressure on the sliding pistons M.
G, G, are two springs forming face-packing for the drum L, which springs are
placed between the drum L and the case R for the purpose of preventing the
escape of steam between the drum and the case at the points where said packing
is placed.
D is a lever connected by a rod with the valve C for the purpose of reversing
the engine when desired.
The mode of operation of our improvements is as follows:-The steam enters the
steam-chest B through the feed-pipe A, and thence passes into the ports or channels
F1 of the case R, following the direction of the arrows, shewn in Figure 2, and
thence passes into the steam-spaces V. Two pistons M, one on each side of the
drum L, are held out in position by the springs N ready to take steam, and the

page_text: steam entering the steam-spaces V exerts pressure on said two pistons M at the same
time, and thus causes the drum L and the shaft O to revolve, and the steam thus
acting on two opposite sides of the drum at the same time relieves the shaft O from
the weight which would be caused by the pressure of the steam on the face of the
drum were the steam admitted to one side only of the drum. The pistons M, as
they are carried around the circle by the revolution of the drum L, are forced down
into the receptacles of the drum as they pass from the beginning of the inner ports
FF, of the case R to the points at G (shewn in Figure 2). The said pistous M,
after passing the said points G, are forced out into the steam-spaces V so as to take
steam by means of centrifugal force aided by the springs N. The steam, after
exerting its pressure on the pistons M as they pass through the steam-spaces V
passes out of the exhaust-port E.
If it is desired to reverse the engine, the lever D is pulled and acts on the valve
C, and allows the steam to flow into the opposite ports F, F, and thus reverse the
action of the engine. The engine can also be packed while running at full speed,
by turning the set-screws J on the outside of the case which adjust the packing-
rings S, thereby avoiding all trouble and waste of time in packing, as is the case
in packing other engines.
Our construction of case is such that there is no action of the steam on the
pistons while working in and out of the drums, thereby preventing friction, and
insuring long wear of pistons. The pistons are isolated or separated from each
other in each of their receptacles, so that steam cannot escape from one to the
other, thereby preventing the steam from interfering with the pistons out of action.
The engine, as so constructed, will also have no dead-points, and there is no loss of
power at any point of the revolution of the drum.
Having thus described our Invention, what we claim and desire to secure by
Letters Patent is,―
1. The combination with the case R provided with recesses a, a, of the drum L
having bevelled flanges L', bevelled packing-rings S provided with flat springs I,
and set screws J, substantially as described, and for the purpose set forth.
2. The combination with the case R having the recesses a, a, and steam-ports
F, F, of the drum L, provided with the bevelled flanges L', sliding pistons M, and
springs N, the steam-spaces V, covers P, bevelled packing-rings S, having flat
springs I, and set screws J, the whole constructed, arranged, and operated in the
manner and for the purpose set forth.
In witness whereof, I, the said Thomas Hawkins, have, for myself and on
behalf of the said Henry Thibalt, hereunto set my hand and seal, this 18th
day of October, One thousand eight hundred and eighty,
THOMAS HAWKINS.
(L.S.)