Mechanism for Controlling and Governing the Movements of Ships' Rudders.
Year: 1899

page_text: Date of Application, 3rd Aug., 1899-Accepted, 7th Oct.,
1899
COMPLETE SPECIFICATION.
Mechanism for Controlling and Governing the Movements of Ships'
Rudders.
I, JORGEN CHRISTENSEN, of No. 7, Market Street, in the City and County of San
Francisco, State of California, U.S.A., Mariner, 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:-
This invention consists in connecting a yoke which is fixed upon the rudder
stock with pistons movable in hollow cylinders containing a liquid, said cylinders
having passages by which the liquid is allowed to pass slowly from one end to the
other of the cylinder when the rudder is turned, the liquid acting as a check to
prevent the rudder from being violently thrown to one side or the other by the
action of the waves. The cylinders are properly pivoted and held in position
while being allowed to turn about their pivots to correspond with the movements
of the yoke or tiller upon the rudder stock.
Fig. 1 is a plan view of one form of steering gear showing the two liquid con-
taining cylinders, one upon each side, one of said cylinders being shown in
section. Fig. 2 is a side elevation of the same. Figs. 3, 4, 5 and 6 are modifi-
cations of the compensating device.
The rudder stock A has fixed upon it a yoke B which is connected by rods C
with pistons C which are movable in cylinders D.
The rudder, itself, may be turned by means of a wheel with any of the usual
or suitable connections which are common in various forms and which I do not
here especially describe.
One well known form of steering mechanism is shown in which a screw E
having right and left threads upon it, is-revolved by the wheel and nuts F which
travel upon right and left threads are connected by rods 'G with yokes upon the
rudder stock, and the turning of the wheel in one direction causes the nuts to
approach each other, and in the other direction to be separated; these movements
acting through the rods turn the rudder.
The strain caused by the shocks of 'the 'waves is so great that it is necessary
to protect the steering mechanism from 'these shocks and 'this is done by the body
of liquid contained within the cylinders with passages H connecting the two ends
of the cylinders so that when the rudder is turned in one direction, the pistons
moving in the cylinders will slowly force a portion of the liquid from one end
to the other, but the main body of liquid will by its inertia prevent any sudden
movements.
The rate at which the liquid may pass from one end to the other of 'the
cylinder, is regulated by a cock or valve I which can be more or less closed or
anoned for that nurnose

page_text: The cylinders may be pivoted at any point. They are here shown as being
pivoted at the rear end, as at J, and the piston rods, C, passing through stuffing-
boxes at both ends of the cylinders, also pass through the pivot standards which
have open slots or channels made for this purpose of sufficient width to allow the
piston rods to move freely and to allow the cylinders to turn sufficiently about
the pivots to accommodate the movements of the rudder and yoke without bind-
ing the piston rods.
In some cases it is desirable to have the piston rods extend into one end of the
cylinder, and carry the pistons upon the inner ends, while the outer ends con-
nect with the yokes upon the rudder stock. In this case there will be a differ-
ence in the amount of liquid contained upon each side of the piston, this differ-
ence being equal to the solid contents of the piston rod, and it is therefore
necessary to make provision for the surplus liquid which will be forced from the
rear of the piston to the front, this surplus being equal, as before stated, to the
solid contents of the piston rod which occupies the front end of the cylinder.
For this purpose I have shown a supplemental cylinder K parallel with the
main cylinder having a piston rod passing through a stuffing-box in the front end
and connecting with the yoke of the rudder stock so as to be movable in unison
with the main piston rod.
A piston is fixed on the inner end of this supplemental rod, and moves in unison
with the main piston, as shown in Fig. 3.
A passage L connects the two cylinders near the front end and when the pistons
are moving toward the rear end of the cylinder the liquid behind the main piston
will be forced through the passage H, which connects the two ends and into the
front portion.
As the front portion of the cylinder has as much less area than the rear portion
as will equal the solid contents of the piston rod, an amount of liquid equal to
this will be forced through the passage L into the smaller supplemental cylinder
following its piston as the two move toward the rear end.
When the pistons again move toward the front, this surplus will pass out of the
small cylinder through the larger one and through the passage connecting the
ends of the cylinder to the rear of the main piston.
The small cylinder is made somewhat longer than the large one at the rear end,
as shown, and the small piston is set correspondingly farther to the rear than
the main one, so that both pistons will reach the rear ends of their cylinders
simultaneously.
The piston rod of the small cylinder is screw-threaded at its outer end where
it connects with the yoke, and by means of nuts O, it can be gradually advanced
to draw the small piston forward in the cylinder, and thus compensate for any
losses by leakage or otherwise, and this will always keep the two cylinders full
of liquid, so that there will be no air space caused by leakage.
In place of the small cylinder arranged as previously described, the piston rod
may be hollow, and made to telescope or slide over a rod fixed in the rear end
of the cylinder, and extending through the piston and into the hollow rod, as
shown in Fig. 4, or a telescopic arrangement of tubes connecting the rear end
of the cylinder with the piston may be employed. The passages connecting the
end of the cylinder may, if desired, be made in the piston rod, itself, as shown at
Fig. 5, and various equivalent devices may be employed producing essentially the
same result.
In Fig. 6, the main cylinder D is made long enough to allow the compensating
cylinder M to extend into it from the rear. A piston fits this cylinder and is
connected and movable in unison with the main piston C by a rod N. When
the pistons move towards the rear of the cylinders, a part of the liquid will pass
through the conduit H to the front of the piston C.. The receding piston in the
cylinder M makes a space equal to that occupied by the piston rod C¹, and the
surplus liquid from the rear of the main cylinder follows the small piston, and

page_text: enters the cylinder M. It is restored to the main cylinder when the pistons move
n the opposite direction.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1st. A brake and balance mechanism for ships' rudders, consisting of pivoted
cylinders containing a liquid having pistons movable therein, and passages by
which the movement of the piston transfers the liquid from one end to the other
of the cylinder, and piston rods extending through stuffing-boxes in the cylinder
heads and connecting with a yoke upon the rudder stock whereby the movement
of the rudder is communicated directly to the piston within the cylinder.
2nd. In a balance mechanism and brake for ships' rudders as described in
Claim 1, a supplemental cylinder having a piston moving in unison with the
piston in the main cylinder, a passage connecting the front ends of the two
cylinders to allow the surplus liquid to alternately pass to and from the main
cylinder, and compensate for the differences in area of the rear and front ends
of the cylinder.
3rd. Counterbalanced cylinders for ships' rudders having passages connecting
their opposite ends, pistons movable in the cylinders and piston rods by which the
said pistons are connected with yokes fixed to the rudder stock, so that the move-
ments of the pistons in the cylinders caused by the turning of the rudder, will
transfer the liquid from one end of the cylinders to the other, and pivot posts
upon which the cylinders are turnable, said posts having slots or openings made
through them to allow the piston rods which extend thro' the rear ends of the
cylinders to slide through the openings in the pivot posts.
C
1900