IMPROVE- MENTS IN STEERING GEAR WORKED BY POWER
Year: 1878

page_text: LETTERS PATENT to Jolin Rankine, of Newcastle-on-Tyne, in the County of
Northumberland, Superintending Engineer, and John Elliot, of Cardiff, in the
County of Glamorgan, Consulting Engineer, for the Invention of "IMPROVE-
MENTS IN STEERING GEAR WORKED BY POWER."
Sealed the 28th February 1879, and dated the 5th September 1878.
PROVISIONAL SPECIFICATION left by the said John Rankine and John Elliot
at the Office of the Commissioners of Patents on the 5th September 1878.
JOHN RANKINE, of Newcastle-on-Tyne, in the County of Northumberland,
Superintending Engineer, and JOHN ELLIOT, of Cardiff, in the County of
Glamorgan, Consulting Engineer. "IMPROVEMENTS IN STEERING GEAR WORKED
BY POWER."
The object of this Invention is to construct a compact, reliable, and efficient
steering gear, which may be worked by steam or water pressure, and without any
intervention of intermediate wheels, rods, and gear, which are so liable to get out
of order at sea.
We employ a long main cylinder fitted with a piston having a piston rod passing
out through each end cover. Cast in one with or bolted to this main cylinder we
employ another smaller cylinder parallel with it; this smaller cylinder is also fitted
with a piston having a piston rod passing out through each end cover.
The piston
rods of the large and of the small cylinder are united by cross heads, so that the two
pistons work together. The cross heads are suitably guided.
To each main piston rod I connect the wheel chains leading over both ends of
the tiller. By admitting fluid pressure to either end of the main cylinder the
piston therein will be forced towards one end or the other of the cylinder, the tiller
being thereby drawn from port to starboard, or vice versa.
The small cylinder
serves to steady the motion of the main piston; for this purpose the main cylinder
slide or other distributing valve (or valves) is by preference by a lever and rod

page_text: connected to a lever on a cock, which by pipes is connected to each end of the small
cylinder, so that when it is open water may flow from one end of the small cylinder
to the other; the small piston thus constantly moving in a dense body of water
serves to steady the movement of the main piston to which it is connected, thus
preventing sudden jerks of the rudder; when the slide valve is closed the cock
also is closed, and becomes perfectly locked.
The main cylinder may be actuated by steam from the boiler, either with or
without expansion and condenser; or it may be worked by water under pressure
from the boiler or from a hydraulic accumulator.
The lever for working the slido valve may be placed midship, or in any other
place convenient for the steersman.
The small cylinder may be fitted with a small cylindrical water supply vessel
having a loaded piston.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Rankine and John Elliot in the Great Soal Patent Office on
the 5th March 1879.
JOHN RANKINE, of Nowcastle-on-Tyne, in the County of Northumberland,
Superintending Engineer, and JOHN ELLIOT, of Cardiff, in the County of Glamorgan,
Consulting Engineer. "IMPROVEMENTS IN STEERING GEAR WORKED BY POWER."
The object of this Invention is to construct a compact, reliable, and efficient
steering gear, which may be worked by steam or water pressure, and without any
intervention of intermediate wheels, rods, and gear, which are so liable to get out
of order at sea.
We employ a long main cylinder fitted with a piston having a piston rod passing
out through each end cover. Cast in one piece with or bolted to this main
cylinder we employ another smaller cylinder parallel with it; this smaller cylinder
is also fitted with a piston having a piston rod passing out through each end cover.
The piston rods of the large and of the small cylinder are united by cross heads, so
that the two pistons work together. The cross heads are suitably guided.
To each main piston rod I connect the wheel chains leading over both ends of
the tiller. By admitting fluid pressure to either end of the main cylinder the
piston therein will be forced towards one end or the other of the cylinder, the tiller
being thereby drawn from port to starboard, or vice versa. The small cylinder
serves to steady the motion of the main piston; for this purpose the main cylinder
slide or other distributing valve (or valves) is connected to a cock, which by pipes
is connected to each end of the small cylinder, so that when it is open water may
flow from one end of the small cylinder to the other; the small piston thus
constantly moving in a dense body of water serves to stendy the movement of the
main piston to which it is connected, thus preventing sudden jerks of the rudder;
when the slide valve is closed the cock also is closed, and becomes perfectly
locked.
The main cylinder may be actuated by steam from the boiler, either with or
without expansion and condenser; or it may be worked by water under pressure
from the boiler or from a hydraulic accumulator.
The lever for working the slide valve may be placed midship, or in any other
place convenient for the steersman.
-
The small cylinder may be fitted with a small cylindrical water supply vessel
having a loaded piston.
Figure 1 of the accompanying Drawings is a side elevation; Figure 2, a plan;
and Figures 3 and 4 respectively enlarged side view and end view of the slide
valve gear of steering gear constructed according to this Invention.
In the arrangements here shewn the steering is performed by means of steam
regulated by means of water pressure.
A is the main cylinder, which is fitted with a piston having a long stroke and
fixed on a piston rod E, which passes out through a stuffing box at each end cover,
as shewn; B is another and smaller cylinder, which may be called the regulating
barrel or cylinder, and is bolted to the main cylinder A by flanges at each end, as
shewn; the small cylinder B is fitted with a piston D having the same stroke as
and working in unison with the main cylinder piston, the two piston rods F and E
being connected by the cross head gudgeons G, G. The piston rod F also passes
out through a stuffing box at each end of its cylinder B. The cross heads are
guided in the guides Ñ, and these latter are fitted with links or hooks I, I', for
connecting the wheel chains leading over both ends of the tiller; one end of the
tiller chain is fastened to the link I, and passes round the block pulley C on one of
the cross heads, and then over the guide pulley P to the tiller; the other end of the
tiller chain is fastened to the link I', and passes round the block pulley C on the
other cross head, and then over the guide pulley P' to the tiller. By admitting

page_text: The
fluid pressure (for instance, steam, as in the case here illustrated) to either end of
the main cylinder A the main piston will be forced to one end or the other of the
cylinder, the tiller being thereby drawn from port to starboard, or vice versa.
distribution of steam or other fluid pressure to either end of the main cylinder A,
as desired, is in this example effected by means of slide valve gear arranged as
shown more clearly in the enlarged detail views, Figures 3 and 4. The slide
valve M is fitted with a tooth rack. J is a tooth sector or quadrant fixed on a
spindle H, on which is also fixed a reversing lever O, which may work against an
ordinary sweep bracket. The spindle H passes out through a stuffing box on the
slide valve jacket Q, the cover of which is shown removed in Figure 2; for clearness
sake;
the spindle H is on its outer end fitted with a double-armed lever h, to each
arm of which is jointed a slotted rod or link j, to the lower ends of which is jointed
the cross bar k, which is guided on the uprights a fixed on a projection from the
valve or valve stem of a sluice cock K, which by the pipes L is connected to each
end of the small cylinder or regulating barrel B; the pipes L are provided with air
vessels. The regulating barrel B and the pipes L are quite filled with water or
other dense liquid. The double-armed lever serves to raise the sluice valve, and
there is a helical spring m, which serves to bring the sluice valve back.
The action of this apparatus is as follows:-When the lever O is in the middle
position, as shown here, the tiller and rudder are also in the middle position, and
are held fast there by the body of liquid in the regulating barrel B, because the
piston D is locked by the liquid, and consequently the piston rod E of main
cylinder also.
The slide valve M is in its middle position, and no steam is consequently admitted
to either end of main cylinder A. The cock K. is also closed, thus shutting off
connection between the two ends of the regulating barrel.
When the lever O is moved to one side the slide valve M is moved towards one
end or the other, admitting steam to one side or the other of the main piston; at
the same time the sluice of the cock K is opened more or less and in proportion to
the motion of the main piston rod E and the tiller connected thereto, so that the
water or other fluid enclosed in the regulating barrel B can flow from one end of
it to the other through the pipes L and cock K. As the piston D thus moves in
a dense body of liquid the inain piston and tiller connected thereto are steadied
thereby, thus preventing sudden jerks of the rudder.
The cylinders A and B need not be arranged side by side, but may for instance be
arranged end for end.
The lever O, although here shewn on the apparatus itself, may, as desired or
required, be placed amidship, or in any other place convenient for the steersman.
And having thus described and ascertained the nature of this Invention we
declare that we claim, the combination of a steering gear main cylinder and an
auxiliary regulating barrel or cylinder, with their piston rods connected by cross
heads, the main cylinder slide valve and the cock for regulating the communi-
cation between the bodies of dense liquid in each end of the auxiliary barrel being
connected and operated together, whereby the motion of the main piston is steadied,
and the rudder tiller is prevented from sudden jerks, substantially as herein-before
described and shown.
In witness whereof, I, the said John Elliot, for myself and on behalf of the said
John Rankine, have hereunto set my hand and seal, this Third day of
March, in the year of our Lord One thousand eight hundred and seventy-