IMPROve- MENTS IN THE METHOD OF AND IN APPARATUS FOR COUNTERACTING the THRUST OF SCREW PROPELLER AND OTHER SHAFTS "
Year: 1883

page_text: LETTERS PATENT to George Alexander Teulon of N° 25 Devonport Road
Shepherds Bush, in the County of Middlesex for an Invention of "IMPROve-
MENTS IN THE METHOD OF AND IN APPARATUS FOR COUNTERACTING the
THRUST OF SCREW PROPELLER AND OTHER SHAFTS
"
PROVISIONAL SPECIFICATION left by the said George Alexander Toulon at
the Office of the Commissioners of Patents on the 7th August 1883.
GEORGE ALEXANDER TEULON of N° 25 Devonport Road Shepherds Bush in the
County of Middlesex "IMPROVEMENTS IN THE METHOD OF AND IN APPARATUS
FOR COUNTERACTING THE THRUST OF SCREW PROPELLER AND OTHER SHAFTS
"
My invention has for its object to reduce to a minimum the thrust-friction of
screw propeller shafts, and thus obviate the loss of power and wear and tear
resulting from such friction.
For this purpose, I counteract the thrust of the shaft by the regulated pressure
of steam or other elastic fluid exerted upon a disc or piston fixed or formed on the
shaft and revolving therewith in a closed chamber, against a fixed abutment ring
or thrust bearing, so that while the shaft is held against any shifting motion in
the direction of its length, the thrust thereof is counterbalanced by a cushion of
steam or other fluid in such chamber instead of, as is common heretofore, by the
bearings in which the shaft runs; and the steam thrust, which is regulated so as
to increase or decrease with the varying thrust due to the different speeds of the
screw, becomes the actual fulcrum of the vessel's forward motion. The said disc
or piston may either be so arranged in the chamber that the steam or fluid pressure
can be admitted either to the one side or the other side thereof, according as the
screw is being driven in the one direction or the other, or the stern ward thrust
produced by the reversal of the screw can, be counteracted by connecting the said
chamber with an exhaust, so that the thrust will then be counteracted by
atmospheric pressure on the side of the piston opposite that which is ordinarily
subjected to the steam pressure.

page_text: It will be evident that my said invention can be carried out in a great variety
of ways,
Thus, according to one arrangement, preferred for its simplicity and compactness,
the crank disc of the propeller shaft is made to constitute the before mentioned
piston on which the steam thrust is exerted, in which case, the chamber in which
the crank disc works is most advantageously arranged between two opposito steam
cylinders of the propeller engine, the chamber being connected steam tight to the
cylinders and having openings through which the piston rods or connecting rods
pass to the pin of the crank disc. Or two single-acting pistons may be connected
by a frame working to and fro in the chamber and having a vertical groove or
transverse slot, in which the block of the crank pin works, in a manner well
understood. The steam or other fluid is admitted into the thrust chamber through
a-roducing valve of any suitable-known construction, by which the pressure may
be regulated to any required degree for counteracting the varying thrust of the
propeller shaft due to varying speeds of the screw, the degree of counter pressure
being by preference always slightly in escess of the thrust.
My invention can also be applied to shafts other than screw propeller shafts in
which it is required to counteract thrust.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Alexander Teulon in the Patent Office on the 1st February
1884.
GEORGE ALEXANDER TEULON of N° 25 Devonport Road Shepherd's Bush, in the
County of Middlesex IMPROVEMENTS IN THE METHOD OF AND IN APPARATUS
"
FOR COUNTERACTING THE THRUST OF SCREW PROPELLER AND OTHER SHAFTS
"
My invention has for its object to reduce to a minimum the thrust friction of
screw propeller shafts, and thus obviate the loss of power, and wear and tear,
hitherto resulting from such friction.
For this purpose, I counteract the thrust of the shaft by the regulated pressuro
of steam, gas, air or other clastic fluid, exerted upon a disc or piston fixed or
formed on the shaft, and revolving therewith in a closed chamber, against a fixed
abutment ring or rings, as a thrust bearing, or between two such bearings; so that,
while the shaft is held against any shifting motion in the direction of its length,
the thrust thereof is counterbalanced by a cushion of steam or other fluid in such
chamber, instead of being borne, as is common heretofore, by the bearings in which
the shaft runs; and the fluid pressure, which is regulated so as to increase or
decrease with the varying thrust due to the different speeds of the screw, becomes
the actual fulcrum of the vessel's forward motion. The said disc or thrust piston
may either be so arranged in the chamber that the steam or fluid pressure can bo
admitted either to the one side or the other thereof, according as the screw is being
driven in the one direction or the other; or, the sternward thrust produced by the
reversal of the screw can be counteracted by connecting the one steam chamber
with an exhaust, so that the thrust will then be counteracted by atmospheric
pressure, on the side of the piston opposite that which is ordinarily subjected to
the steam pressure.
It will be evident that my said invention can be carried out in a great variety
of ways. Thus, according to one arrangement, preferred for its simplicity and
compactness, the crank disc of the propeller shaft is made to constitute the
before mentioned piston on which the steam thrust is exerted, in which case, the
chamber in which the crank disc works may be advantageously arranged between
two opposite steam cylinders of the propeller engine, the chamber being connected.
steam tight to the cylinders, and having openings through which the piston rods or
connecting rods pass to the pin of the crank disc. Or two single acting pistons,
enclosing between them a steam space, may be connected by a frame working to
and fro in the chamber, and having at its centre a vertical groove or transverse
slot, in which the block of the crank pin works, in a manner well understood. The
steam or other fluid is admitted into the thrust chamber through a reducing valve
of any suitable known construction, (that employed in the Westinghouse Air brake
may be cited as most simple and efficient) by which the pressure may be regulated
to any required degree for counteracting the varying thrust of the. propeller shaft.
due to varying speeds of the screw; the degree of counterpressure being by
preference always slightly in excess of the thrust.
My invention can also be applied to shafts other than screw propeller shafts, in
which it is required to counteract thrust.
Fig. I of the accompanying drawings shews a double-crank screw shaft, having a
tbrust piston A A fixed on its forward end, and revolving, as shewn in section, in
a closed chamber between two pairs of concentric thrust rings G G formed on the
cover D, and in the forward end of the chamber. A double acting valve C C
admits steam as required to either side of the said piston, while the other side

page_text: thereof is held open to the exhaust; S S being the steam pipe and steam spaces,
E E the exhaust pipe and vacuum spaces. Bb are the handles of a well known
form of reducing valve (that employed in the Westinghouse air brake) for
regulating at will the pressure of the admitted steam, in accordance with the
varying degrees of speed and thrust: some such regulation of the pressure !
employed is essential. G, g, the fixed, and the revolving, thrust bearings, should
be faced with antifriction metal, as indicated, and ordinary methods of lubrication
applied. Fig. 11 shews a pair of coupling discs A A such as conjoin two lengths
of screw shaft, combined to form an annular piston revolving in a closed chamber
as shown: H H represent a rectangular ridge and groove across the opposed faces 1
of the two discs, which will prevent any strain of torsion coming on the coupling
bolts, and thereby keep the two halves of the piston truly in line. The other parts.
lettered in this Figure are the same as in Fig. I, and the same description applies
to both.
·
Fig. III shows a closed chamber A A (subject to atmospheric pressure on the 1
rear side) with combined crank disc and thrust piston B, fitted to revolve in rear
plate of chamber, the crank pin C being worked by a solid slotted cross link D,
from an inverted vertical cylinder, as shown. Fig. IV is a transverse vertical.
section of Fig. III, shewing in addition G G, the fixed abutment ring against
which the thrusts are exerted: F F are bolts holding the backing ring HH against
-the-stern side-of-the-thrust ring, when the engine is reversed. J J are the inlet
and exhaust passages of a suitable regulating valve outside the chamber A, for
__ making it alternately (as the direction of the screw thrust may require) a steam
space for exerting thrust outwards on the disc B, or a vacuum chamber for counter--
acting, by the atmospheric pressure on HH, the roverse thrust, sternwards. K is i
the flanged cover of the closed thrust chamber.
Fig. V of the accompanying drawings is a longitudinal section, and Fig. VI is a
sectional plan of a simple form of engine to which my invention is applied. A A aro
two single acting cylinders fixed in line with one another on each side of a central
chamber B, which is a cylinder shewn in transverse sectional elevation, Fig. VII,
having its axis perpendicular to the axis of A A. The two pistons CC are
connected by a reciprocating frame D having a vertical slot in which works the
pin E projecting from the crank disc F, which is fixed on the propeller shaft G.
This disc is fitted with suitable packing to revolve in the cylinder B, and it is
prevented from shifting laterally by a collar b and a backing ring bolted on and
held against the stern side of said collar. The chamber B is charged with steam or
other elastic fluid through pipe K supplied under a regulated pressure-through a
reducing valve indicated at L-such that, acting on the area of the disc Fit
counterbalances approximately, or slightly exceeds, the thrust of the propeller
communicated through the shaft G. I have shewn rocking valves H for alternating
the admission and emission of the steain: these being worked from an eccentric J
which may be on a subsidiary shaft driven from a slot of the reciprocating frame D
in the same way as the shaft G is driven. It may be readily understood however,
that valves or slides of any known kind might be used for admission and omission
of stean. It is also obvious that when the crank is worked by a connecting rod,
the crank disc F or a separate disc fixed on the shaft G, may be subjected to
pressure as described for counteracting longitudinal thrust, whether that resulting
from a propeller or from any other cause. In case of reversal of a propeller, when
the direction of the thrust is reversed, the chamber B may be put in communication
as shewn by the pipe M with the condenser, so that the disc F becomes subjected
on its outside to nearly the unbalanced atmospheric pressure.
Having thus described the nature of my invention and in what manner the samo
is to be performed, I claim :-
First. Counteracting the different and the contrary thrusts of a screw propeller
or other shaft by regulated and reversible elastic pressure (and exhaust) acting
together on a thrust piston fixed on the shaft, and fitted to revolve therewith, but
without axial motion, in a cylindrical chamber, substantially as herein described.

page_text: Second. In combination with a screw propeller or other shaft subject to end
thrust, a thrust piston (combined as a crank disc) fixed on the shaft. and fitted to
revolve therewith, but without axial motion, in a closed chamber, in which a
regulated elastic pressure (greater or less than that of the outer air, according as
the thrust is directed inwards or outwards) is maintained, for counteracting the
different thrusts, substantially as herein described.
In Witness whereof I the said Georgo Alexander Teulon have hereunto set my
hand and seal this Thirtieth day of January in the year of our Lord One thousand
eight hundred and oighty-four.
ΑΠΟΦΑΣ A METTON 101
GEORGE A.
TEULON