Improvements in Rotary Engines.
Year: 1898

page_text: Date of Application, 19th Apr., 1898-Accepted, 9th July, 1898
COMPLETE SPECIFICATION.
Improvements in Rotary Engines.
I, REUBEN PALMER JARVIS, Labourer of Smith Centre, in the County of
Smith and State of Kansas, United States of America, do hereby declare the
nature of my invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The object of the invention is to provide a new and improved rotary engine,
which is simple in construction, very effective in operation, and arranged to
utilize the motive agent expansively and to the fullest advantage, the friction
of the working parts being reduced to a minimum, and leakage of steam com-
pletely prevented.
The invention consists of novel features and parts, and combinations of the
same, as will be fully described hereinafter and then pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
specification, in which similar characters of reference indicate corresponding
parts in all the figures.
Figure 1 is an end elevation of the improvement;
Figure 2 is a longitudinal sectional elevation of the same, on the line 2-2 of
Figure 1;
Figure 3 is a transverse sectional elevation of the improvement, on the line 3-3
of Figure 2;
Figure 4 is a side elevation of the same with parts in section ;
Figure 5 is an end elevation of the cylinder with the cylinder heads removed
and parts in section;
Figure 6 is a sectional side elevation of the improvement, on the line 6-6 of
Figure 1;
Figure 7 is an enlarged cross section of one of the auxiliary exhaust valves in
a closed position ;
Figure 8 is an enlarged sectional plan view of part of the improvement, on the
line 8-8 of Figure 1;
Figure 9 is an enlarged side elevation of one of the piston heads, its trun-
nions and crank shaft, with parts in section ;
Figure 10 is an end elevation of the same, with parts in section on the
line 10-10 of Figure 9;
Figure 11 is a sectional plan view of the same, on the line 11-11 of
Figure 10;
Figure 12 is a similar view of the same, on the line 12-12 of Figure 9;
Figure 13 is an enlarged side elevation of the packing for the side of the
piston head;
Figure 14 is a perspective view of one member of the said packing;
Figure 15 is an enlarged cross section of part of the piston and the crank
shaft, the section being on the line 15-15 of Figure 16;
Figure 16 is a sectional side elevation of the same;
Figure 17 is a sectional plan view of the same;
D

page_text: Figure 18 is an enlarged perspective view of one of the packing members;
Figure 19 is a face view of the partition between the high and low pressure
cylinders for the compound engine shown in Figure 21;
Figure 20 is a sectional side elevation of the same, on the line 20-20 in
Figure 19;
Figure 21 is a sectional side elevation of the improvement, as arranged for a
compound engine;
Figure 22 is a diagrammatic view of the high pressure cylinder, its piston and
piston head;
Figure 23 is a similar view of the low pressure cylinder, piston and piston
heads;
Figure 24 is a sectional side elevation of a modified form of the improvement
arranged as a duplex compound engine; and
Figure 25 is a similar view of another modified form of the improvement
arranged as a quadruplex engine.
The improved rotary engine is provided with a cylinder A, having ring-shaped
cylinder heads A1, A2, and in said cylinder is mounted eccentrically a piston B
made ring-shaped, and provided with spiders B1, B2 having hubs B3, B4 mounted
to rotate loosely on a shaft C, having its hexagonal ends C3 secured in bearings D¹
removably mounted in standards D, and secured therein together with the hexa-
gonal ends C2, by bolts D2, as is plainly illustrated in the drawings, special refer-
ence being had to Figure 4. On the hub 133 of the piston B is secured or formed
a pulley B, for transmitting the rotary motion of the piston to other machinery.
The peripheral surface of the piston B is in contact with the inner surface of the
cylinder A at a packing E, contained in a recess in the top of the said cylinder,
and adjustable towards the peripheral surface of the piston B by two
wedges E1, E2 fitted to slide one upon the other, and adjustable at their base ends
by set
screws E³, E, respectively screwing in the sides of the cylinder
heads A1, A2, as is plainly illustrated in Figure 2. The piston B is provided with
a plurality of piston heads F, F1, F2, F3, as shown in the drawings, all pivotally
connected at their inner ends with a crank arm C¹, formed or secured on the
fixed shaft C.
The piston heads F, F1, F2, F3 extend through slots B6 (Figure 3) in the rim
of the piston B, and each of the heads is fitted to slide in a trunnion G, mounted
to rock in suitable bearings B7, attached to or formed on the inside of the piston,
as is plainly indicated in Figures 1 and 3. The inner end of each piston
head F, F, F2, F3 is provided with a sectional box F5, engaging the crank arms C¹
and held adjustably in a frame F6, bolted or otherwise secured to a cross arm on
the corresponding piston head. Wedges F7 are fitted to slide in the frame Fo
against the boxes F5, so at to adjust the latter in the frame to take up wear of
the boxes on the crank arm.
Each of the piston heads F, F1, F2, 13 is provided on its sides with a packing
(see Figures 9 to 14), consisting principally of a guiding plate H, adapted to abut
with its outer straight face against the trunnion G; and on said plate are
formed guideways H₁ for a second plate H2, adapted to abut against the side of
the piston head F, the inner end of said plate being provided with a screw rod H³,
mounted on a bracket Hattached to the piston head, the said screw rod being
engaged by nuts H abutting against the said bracket, to adjust the screw rod and
securely hold the plate H2 outward, to take up wear. The plate H2 is provided
with wedges H6 engaging correspondingly shaped wedges H7 on the other plate H,
so that when the screw rod H3 and the plate H2 are moved outward, the
wedges H and H7 slide upon one another to move the two plates H and H2 apart
and take up all wear at the side edges of the piston heads and the corresponding
trunnions G.
Each of the trunnions G is provided on opposite faces of the piston head F with
wedge-shaped packings G, having their base ends extending from opposite ends

page_text: of the trunnion, as is plainly indicated in Figure 11, each packing G¹ being
pressed on at the base or other end by a spring G2, abutting against a bearing
plate G³ carried by studs G, screwed in the end of the trunnion G. The device
just described is enclosed at each end of the trunnion by a dust-cap G5 fastened
by a screw G6 to the trunnion. It is evident that wear on the faces of each
piston head is readily taken up by the wedge-shaped packings G¹, pressed inward
by the springs G2, as described. Wedge-shaped packings 18 are also arranged
in the bearings B7 for the trunnions, to engage the outer peripheral surface of the
trunnions at opposite sides, as plainly indicated in Figure 10, to take up wear of
the trunnions in the bearings.
In order to prevent leakage of steam, each trunnion is provided at its inner face
with a packing I, for making a steam-tight joint between the trunnion and the
piston head, so that steam is not liable to leak from the cylinder, past the piston
head to the inside of the piston and to the atmosphere. The packing I is pro-
vided with a casing I', bolted to the trunnion G, as shown in Figure 9; and in
the sides of the said casing are arranged wedges I2, engaged by wedges I³, fitting
against the faces of the piston head, as is plainly shown in Figure 12, said
wedges 13 being somewhat less in length than the casing, their base ends being
pressed on by springs I held in the ends of said casing I'. Thus, the springs
force the wedges I³ inward along the fixed wedges 12, so as to form a steam-tight
joint with the faces of the piston heads, to prevent leakage. The wedges I³ are
held against outward movement by a rectangular open plate or ring 1º, carried
by brackets I, bolted or otherwise fastened to lugs on the casing I' See
Figure 10.
Each of the hubs B3 and B is provided with an internal bearing J, having a
conical bore for fitting on the corresponding beveled part C3 of the crank shaft C.
See Figures 2, 15, 16 and 17. Each bearing J is provided on its outside with
boxes J, mounted to slide longitudinally on bolts J2, secured to the corresponding
hub B3 or B. On each bolt J within the box J¹ is coiled a spring J³, one end
of which rests against the box J¹, the other end pressing against the head J4 of
the bolt, so as to press the bearing inwardly to fit snugly upon the beveled
part of the crank shaft C. By this arrangement, all wear incident to the
piston revolving on the stationary shaft C is taken up, and an easy running
assured.
Each
The portion C of the shaft C between the beveled part C3 and the hexagonal
end is cylindrical, see Figures 16 and 17; and in this portion C is fitted
loosely a sectional ring J, pressed against the outer end of the bearing J by
springs Je held in guideways J7, fitted in bearings D³ in the standard D).
spring has its outer end abutting against a plate Js, fitted to slide in the guide-
way J, and adjusted therein by a screw J, screwing in a lug on the standard D.
In order to pack the piston in the cylinder heads A¹, A², I provide the follow-
ing arrangement, special reference being had to Figures 1, 2, 6 and S.
The outer ends 13° of the piston rim are beveled externally, and each bevelled
end is engaged by a packing ring K, made wedge-shaped in cross section; and
on the ring K are formed boxes K', fitted to slide longitudinally on bolts K²,
secured to the cylinder heads A¹ or A². On each bolt K2 within the correspond-
ing box K¹, is coiled a spring K³, the inner end of which presses on the box K',
the outer end abutting on the under side of the head K of the bolt K2, so that
the packing ring is guided longitudinally on the bolts, and pressed inwardly
by the springs, to insure a steam-tight joint between the piston rim and the
cylinder heads.
In the cylinder A on the opposite sides of the packing E are formed inlet
ports a and b, opening into the interior of the cylinder at the heads A1, A2, as
plainly indicated in Figure 3, and forming corresponding recesses in said heads,
as will be apparent by reference to the figure mentioned. The upper ends of the

page_text: ports a and b connect with ports c and d, respectively, adapted to be connected
with a port e formed in a valve L, mounted to turn in suitable bearings in the top
of the cylinder A above the packing E. The valve port e is adapted to register
with a steam or compressed air inlet pipe N, leading from a boiler or other suit-
able source of motive agent supply. On the stem of the valve L is secured a
-handle L', under the control of the operator, for turning the said valve L either
to cut off the supply from both ports c and b, or to connect either of said ports
with the steam supply.
As shown in Figure 3, the port e registers with the steam supply inlet and the
port c, so that the motive agent can pass into the cylinder at the right-hand side
thereof by way of the port a, to act on the piston head F and turn the piston in
the direction of the arrow a¹. When it is desired to reverse the engine, the
valve Lis turned to connect the port d with the supply pipe N, so that the motive
agent passes through the port d, and by way of the port b into the cylinder A at
the left-hand side thereof, to act on the piston head F3 and turn the piston in
the inverse direction of the arrow a¹.
Near the lower ends of the ports a and b are arranged exhaust valves 0,0¹,
respectively, adapted to connect the said ports with the atmosphere, it being
understood that when the valve L connects its port e with the port c, the valve O is
closed, while the other exhaust valve O' is opened, so that the exhaust steam in
front of the piston head passes into the port b, and by way of the valve O¹ to the
atmosphere. When the valve L is turned, as previously described, for reversing
the engine, then the valves 0, 0¹ are simultaneously turned with it to open the
valve Ŭ and to close the valve 0¹; exhaust then takes place by way of the port a.
and the valve O.
In order to turn the valves L, O and O¹ simultaneously, I provide the stems of
the valves 0, 0¹ with arms 03, 03, (see Figure 1). respectively, connected by
links P, P with the handle L¹, so that when the operator turns the latter either
to the right or to the left, a simultaneous motion is given to the valves 0, 0¹, for
the purpose mentioned.
In order to utilize the steam expansively, the ports a and b are extended a suit-
able distance on the sides of the cylinder A, as is plainly shown in Figure 3, so
that live steam can pass into two compartments in the front and rear of a piston
head and act simultaneously on two piston heads for a while, until the preced-
ing piston head passes the end of the corresponding port to cut off the steam
from the preceding working chamber and allow the steam to operate expansively
therein, until the first piston head passes the additional exhaust ports f and g
leading to the exhaust valves Q and R, respectively, mounted to turn in suitable
bearings attached to the cylinder A. See Figures 1, 5 and 7.
The valves Q and R are provided on their valve stems with bevel gear
wheels Q', R¹, in mesh with bevel gear wheels Q2, R2, having
their shafts Q3, R³ provided with arms Q, R, connected by links Q
and R5 with the arms 0203 of the exhaust valves 0 0% Now, when
the valves L, 0, 01, are in the position shown in Figure 3, the valve Q is closed,
while the other valve R connects the interior of the cylinder A by the port g with
the atmosphere, to allow steam to escape at this point from the cylinder, that is,
between the piston heads F2 and F3. When the head 12 has passed the port g
the exhaust steam between the heads F¹, F is exhausted through the valve R
after the steam has operated expansively against the head 1, as previously
mentioned. When the valves L, 0, 0¹ are shifted, as previously explained, to
reverse the engine, the valve R is closed and the valve Q is opened to connect
the interior of the cylinder A by way of the port f with the atmosphere. The
same operation now takes place only in a reverse order, that is, the steam is
exhausted through the valve Q after it has operated expansively against the
lowermost piston head.
In the arrangement shown in Figures 19, 20 and 21, the engine is provided

page_text: with a high pressure cylinder S and a low pressure cylinder S¹, separated from
each other by a head or partition S2, having a port h connecting the lower end
of the high pressure cylinder S with an inlet valve T for the low pressure
cylinder S. The valve T moves with the inlet valve T", corresponding to the
valve L of the engine previously described.
In the cylinder S (Figure 22) is mounted to turn a piston U, having say four
sliding piston heads U₁, constructed and operating as above described in reference
to the piston B and its piston heads F, F1, F2, F3; but the low pressure cylinder S¹
(Figure 23) has a piston U2 with but three piston heads U³, to allow more room
for the expanded steam to work against the piston heads in the cylinder S¹. The
valve mechanism in other parts for the cylinders S, S' is exactly the same as
above described in reference to the single cylinder engine, the low pressure
cylinder having the steam ports c, d leading from the upper part to suitable
points lower down for transmission of steam thereto.
In the modified form shown in Figure 24, a high pressure cylinder V is placed
alongside a low pressure cylinder V, and in said cylinders operate eccentrically
the pistons W, W, having four piston heads W2, W. An inlet valve V2 carries a
reversing lever or handle V³, for directing the steam into either the lower or
upper portion of the cylinder, and exhaust valves V*, V* are provided, operating
in unison with the valve V2, as previously described. The steam operates expan-
sively in the cylinder V, and the main exhaust steam passes diametrically
opposite the inlet valve V2 by ports i to the inlet valve V of the low pressure
cylinder V. The latter is provided with two sets of exhaust valves V, V7 and
V8, V in connection with the valve V, and the same as the valves L, 0, 0¹, Q
and R previously described. All of the valves of the cylinder V are connected
with the valves of the cylinder V, so that upon shifting the reversing lever V³ all
the valves of both cylinders are shifted simultaneously. The mechanism for
connecting the valves with each other may be of any approved construction; and
the one shown is so apparent in its workings that further description is not
deemed necessary.
Thus, for
The ports and V8, represented in Figure 24 are auxiliary ports whereby steam
may be turned into both engines from the boiler at the same time. In this way
high pressure work may be done in all the low pressure cylinders. The boiler
connections, etc., are independent of the other levers and inlet port.
instance, if the port i on the lower side of the high pressure engine, shown in
Figure 24, is open, and also the port V8 in the cylinder V, then it is obvious that
high pressure work is done in both cylinders. if the engine be reversed and the
ports on the upper side be opened, the action would be the same, except in an
inverse direction. All I claim on this is a set of auxiliary ports made to register
with the boiler by means of any approved valve, inlet port and leverage connec-
tious. The ports are designed to be used principally in starting heavy loads. By
this means all the low pressure engines may be used simultaneously as high pres-
sure engines. Or the auxiliary ports may be dispensed with, and low pressure
work be done in the usual manner. These ports, it will be understood, are
opened and closed by valves independent of the other valve mechanism, likewise
the feed pipe or pipes and levers.
The
As shown in Figure 25, the compound engine is provided with a high pressure
cylinder Y and three low pressure cylinders Y', Y2 and Y3 each containing a
piston Z, having a plurality of piston heads. The inlet valve Y for the high
pressure cylinder Y directs the live steam either to the lower or top portion of
the cylinder, according to the direction in which the engine is to be run.
high pressure cylinder Y connects with the low pressure cylinder Y¹ by way of a
reversing valve Y5, the same as the one described in reference to Figure 24: The
low pressure cylinder Y¹ connects in a like manner by the reversing valve Yo with
the second low pressure cylinder Y, similar to the cylinders A and V above
referred to. The exhaust valves Y' and Y8 of the high pressure cylinder Y con-

page_text: nect with the third cylinder Y³, so that the final exhaust steam not passed from
the cylinder Y to the cylinder Y' is allowed to pass into the cylinder to do
work therein in the same manner as the steam in the cylinder Y. As only a
portion of the steam passes from the cylinder Y into the cylinder Y¹ and the
remainder into the cylinder Y3, it is evident that the cylinder Y¹ can be of the
same size as the cylinder Y, and yet the steam will work expansively therein.
Further cylinders could be connected with the cylinders Y', Y2 and Y³ if desired,
to receive the exhaust steam for more work.
From the foregoing it will be seen that the engine is very simple, compact
and durable, and the strain and friction is equally distributed throughout the
engine. The several parts are easy of access, and the inlet and exhaust ports
can be made sufficiently large, without perceptibly affecting the efficiency. As the
engine has no continuously working valves and the steam flows constantly, it is
evident that the engine can be easily governed, and is capable of attaining an
extremely high rate of speed. The engine is easily reversed, and runs one way as
well as the other. In stopping a load, or for instance in lowering carriages into
mines, the reverse lever L is turned so as to draw on a vacuo as much as desired,
or it can be turned so as to compress the air in the cylinder compartments to
the necessary compression to hold the load, the degree of compression being
regulated by the reverse lever. By a specially devised mechanism, this com-
prssed air may be stored in the air chamber and used to help in hoisting the
next load.
It is also obvious from the construction of the compound engine that the steam
may be relatively inexpensively superheated in its exhaust from one engine to
the other.
Having now particularly described and ascertained the nature of my invention,
and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a rotary engine, the combination with a cylinder, of a fixed shaft having a
crank arm in the cylinder, a piston eccentrically mounted in the cylinder and
turning loosely on the said shaft, said piston having its rim slotted, rocking
bearings or trunnions carried by the said piston, and piston heads sliding in the
said bearings and having their inner ends pivotally connected with the crank arm
of the said shaft, substantially as shown and described.
2. In a rotary engine, the combination with a cylinder, of a fixed shaft having
a crank arm in the cylinder, a piston eccentrically mounted in the cylinder and
turning loosely on the said shaft, said piston having its rim slotted, rocking
bearings or trunnions carried by the said piston, piston heads sliding in the said
bearings and having their inner ends pivotally connected with the crank arm of
the said shaft, and packings carried by the said bearing or trunnion to engage
the piston head, substantially as shown and described.
3. In a rotary engine, the combination with a cylinder, of a fixed shaft having
a crank arm in the cylinder, a piston eccentrically mounted in the cylinder and
turning loosely on said shaft, said piston having its rim slotted, rocking bearings
or trunnions carried by said piston, piston heads sliding in said bearings, and
having their inner ends pivotally connected with the crank arm of said shaft, a
reversing valve for directing the motive agent to either side of the cylinder,
exhaust valves operating with the reversing valves, and intermediate or auxiliary
exhaust valves intermediate of the inlet and exhaust valves, substantially as
shown and described.
4. In a rotary engine, the combination with a cylinder, of a fixed shaft having
a crank arm in the cylinder, a piston eccentrically mounted in the cylinder and
turning loosely on said shaft, said piston having its rim slotted, rocking bearings
or trunnions carried by said piston, piston heads sliding in said bearings, and
having their inner ends pivotally connected with the crank arm of said shaft, a 5

page_text: reversing valve for directing the motive agent to either side of the cylinder,
exhaust valves operating with the reversing valves, intermediate or auxiliary
exhaust valves intermediate of the inlet and exhaust valves, and means for con-
necting the intermediate valves with the exhaust valves, to permit of shifting the
several valves simultaneously, substantially as shown and described.
5. A rotary engine, comprising a cylinder having an inlet port and two open
exhaust ports, a fixed shaft having a crank arm extending in said cylinder, a
piston eccentrically mounted in the cylinder and turning loosely on said shaft,
rocking trunnions on said piston, and piston heads fitted to slide in said trunnions
in slots in the piston rim, the inner ends of said piston heads being pivotally con-
nected with the crank arm of the said fixed shaft, said heads being adapted to
successively pass said ports so that live steam is taken at the inlet port, a portion
of the steam being exhausted at the first exhaust port and the remainder at the
last exhaust port, substantially as shown and described.
6. A rotary engine, comprising a cylinder having an inlet port and two open
exhaust ports, a fixed shaft having a crank arm extending in said cylinder, a
piston eccentrically mounted in the cylinder and turning loosely on said shaft,
rocking trunnions on said piston, piston heads fitted to slide in said trunnions
in slots in the piston rim, the inner ends of said piston heads being pivotally con-
nected with the crank arm of the said fixed shaft, said heads being adapted to
successively pass said ports so that live steam is taken in at the inlet port, a portion
of the steam being exhausted at the first exhaust port and the remainder at the
last exhaust port, and a low pressure cylinder into which passes the steam from
the first exhaust port, said cylinder being provided with inlet and exhaust ports
and connecting a piston and piston heads similar to the one in the first-named
cylinder, substantially as shown and described.
7. A rotary engine provided with a cylinder, a piston mounted to turn eccen-
trically therein and formed on the sides of its rim with external annular heads,
and packing rings mounted yieldingly in a longitudinal direction on the cylinder
heads and formed with external bevels fitting on the piston bevels, substantially
as shown and described.
8. A rotary engine provided with a cylinder, a piston mounted to turn eccen-
trically therein and formed on the sides of its rim with external annular heads,
packing rings mounted yieldingly in a longitudinal direction on the cylinder
heads and formed with external bevels fitting on the piston bevels, each packing
ring being provided with boxes or pockets, a bolt secured to the cylinder head,
and forming a guide for the pocket, and a spring coiled on the bolt within the
box, one end of said spring resting on the inner end of the pocket, the other end
abutting against the under side of the bolt head, substantially as shown and
described.
9. A rotary engine provided with a movable piston head, a trunnion through
which passes said head, packings for the edges of said head, and comprising two
packing plates having wedges fitted to slide upon one another, to move the
packing plates apart, one of the plates being guided in the other, and means for
adjusting one of the plates longitudinally on the other, substantially as shown
and described.
10. A rotary engine provided with a rocking trunnion, a piston head fitted to
slide therein, and spring-pressed packing wedges interposed between the faces of
the piston head and the walls of the trunnion opening through which passes the
said head, substantially as shown and described.
11. A rotary engine provided with a rocking trunnion, a piston head fitted to
slide therein, spring-pressed packing wedges interposed between the faces of the
piston head and the walls of the trunnion opening through which passes the said
head, and dust caps secured to the ends of the trunnions to protect the trunnion
opening and wedges against dust, substantially as shown and described.
12. A rotary engine provided with a rocking trunnion, a piston fitted to slide

page_text: therein, and a packing for the inner end of the said head and carried externally
by said trunnion, substantially as shown and described.
13. A rotary engine provided with a rocking trunnion, a piston head fitted to
slide therein, a packing for the inner end of the said head and carried externally
by said trunnion, said packing comprising a box having an opening in its bottom
for the passage of said head, fixed and slidable wedges in said box, the slidable
wedges being spring-pressed and engaging the faces of said head, and retaining
plates removably carried by said box, and engaging said wedges to hold the same
in the box, substantially as shown and described.
L
14. A rotary engine provided with a movable piston head having its end pro- -
vided with a detachable frame, boxes held to slide in the frame, and keys for
adjusting said boxes, substantially as shown and described.
15. A rotary engine provided with a fixed shaft having conical bearing por-
tions, and a piston mounted to turn on the shaft, and having its hubs provided
with longitudinally yielding bearings fitted on the said conical bearing portions,
substantially as shown and described.
16. A rotary engine provided with a fixed shaft having conical bearing por-
tions, a piston mounted to turn on the shaft, and having its hubs provided with
longitudinally yielding bearings fitted on the said conical bearing. portions,
cach bearing being provided with boxes or pockets secured to the hubs, bolts
extending into the boxes for the bearings to slide on the bolts, and springs
coiled on said bolts within the boxes, for pressing the boxes and the bearings,
inward, substantially as shown and described.
17. A rotary engine provided with a fixed shaft having conical bearing por-
tions, a piston mounted to turn on the shaft, and having its hubs provided with
longitudinally yielding bearings fitted on the said conical bearing portions,
and a spring-pressed sectional dust ring engaging the outer end of said bearing,
and fitted to slide in stationary bearings on the engine frame or standard, sub-
stantially as shown and described.
18. A rotary engine provided with a fixed shaft having. conical bearing por-
tions, a piston mounted to turn on the shaft, and having its hubs provided with
longitudinally yielding bearings fitted on the said conical bearing portions, a
spring-pressed sectional dust ring engaging the outer end of said bearing, and
fitted to slide in stationary bearings on the engine frame or standard, and means
for adjusting the tension of the springs for the said dust ring, substantially as
shown and described.
Dated this 10th day of A 1900