IMPROVEMENTS IN STEERING GEAR."
Year: 1881

page_text: LETTERS PATENT to Joseph Knight Kilbourn, of Brixton, in the County of
Surrey, and George Fossick, of Stockton on Tees, in the County of Durham,
for an Invention of IMPROVEMENTS IN STEERING GEAR."
"
PROVISIONAL SPECIFICATION left by the said Joseph Knight Kilbourn and
George Fossick at the Office of the Commissioners of Patents on the 15th
January 1881.
JOSEPH KNIGHT KILBOURN, of Brixton, in the County of Surrey, and GEORGE
FOSSICK, of Stockton on Tees, in the County of Durham, "IMPROVEMENTS IN
STEERING GEAR."
Our Invention relates to improvements in steering gear, whereby the simplicity
of construction, durability, efficiency in working, economy, and other advantages
are obtained.
In carrying out our Invention as applied to that class of steering gear in which
the power is transmitted by the use of a quick threaded screw or spiral bolt, the
nut which turns the screw is made in segments, the number of which correspond to
the number of threads in the screw or sides to the spiral bolt. The aggregate of
these segments forms a complete circle, the external surfaces being in the form of a
double truncated cone; the segments are held together and in position by a double
cross head bored to fit the surfaces of the cone and drawn together by strong bolts.
In the first fitting of the nut the contact edges of the segments may have left
thereon file spots to be subsequently reduced, or may have intervening strips of
thin metal to be removed whenever it is desirable to take up the "lost motion
occasioned by wear, this being an important object of this part of the Invention,
and which is thus effected in an economical manner.
"
In order to reduce excessive friction we employ two series of metal balls placed
between the surfaces, which sustain the end thrust in both directions; these balls
may be of hardened steel or of chilled iron or other suitable material of such
hardness that pressure upon them shall not cause abrasion.
The arrangement herein before described is applicable whether the power is
applied by hydraulic agency or otherwise.
When hydraulic power is used we overcome the excessive rigidity with which

page_text: the rudder is held, or relieve the shock caused by heavy seas against the rudder, in
the following manner:-In addition to the well known "relief valves," which are
usually located at a point more or less remote from the rudder, we employ an
arrangement of relief springs in very close proximity to the tiller, through which
all the power is transmitted to the rudder stem, and which will in event of
excessive strain yield to a predetermined extent, and recover again as soon as this
excessive strain is removed. The nearness of these springs to the rudder stem
causes them to give instantaneous relief, thereby acting as a cushion to the tiller
or its substitute.
These relief springs are especially applicable to two modifications of hydraulic
steering gear, which may be respectively classed as "vertical" and "horizontal."
In both modifications either one or two cylinders may be used. With the
"vertical," with a single cylinder, the latter is placed directly over the rudder
stem.
With the vertical, with two cylinders, one cylinder is placed on each side of the
rudder stem. In both cases the ram or rams work one cross head which contains
and carries the nut. In each case, whether one or two vertical cylinders are used,
the spring boxes form part of a disc plate attached to the screw or spiral bolt and
turning with it. This plate forms the coupling which connects the screw or spiral
bolt to the rudder stem, the tiller resting between two or more of the relief springs,
closing them when ever there is excessive strain upon the rudder. Inasmuch as
the springs turn with the screw or spiral bolt, the action of the tiller against the
springs is always at the same angle.
In the "horizontal" modification the ram or piston rod is tubular and contains
the springs. The connection from the rams to the rudder stem may be made in
various ways, but we prefer to make this connection by means of a rack on the
ram and a pinion on the rudder stem; by this method the power is always applied
at right angles to the resistance. The rack is tubular and has a loose motion on
the ram to the extent of the relief motion obtained from the springs, and any
excessive strain or blow upon the rudder is transmitted through the pinion to the
rack, which in turn closes the springs in either direction, as the case may require,
the springs returning to their original position as soon as the rudder is relieved
from the excessive strain. In order to insure greater strength together with
smoothness of action, both rack and pinion are shrouded to the pitch line, and with
a view to maintain the pinion and rack in gear a vertical roller is placed against
the back of the rack, and another against the opposite side of the pinion resting
against the shrouding, the two being secured together by a cap plate.
When two horizontal cylinders are used both cylinders form part of or are
secured to one and the same bed plate at diagonal corners with the rudder stem.
Another feature of our Invention relates to the "valve gear," which controls the
power for working the steering mechanism, and has for its object obtaining such an
arrangement of equilibrium valves as insures easy movement, certainty of action,
and great simplicity of construction.
This object is effected in the following manner :-
In a valve chest located on or near the pumps, and connected by a pipe to the
cylinder or cylinders at the rudder head, we provide two valves, one which, for
convenience, we term the "rudder valve," the other, having its seat on the rudder
valve, we term the "wheel valve." Each of these two valves has an entirely
independent movement. The rudder valve has two compartments, from which are
ports or passages covered by the wheel valve. At each end of the rudder valve is
a tubular valve rod, the one end of each opening into one of the before named
compartments. One of these valve rods extends through the chest into a chamber
filled with a liquid under constant pressure from the pumps, the other rod
extending through a supplementary chamber, called the exhaust chest, into which
the tubular rod has an opening. On the end of this valve rod is a piston fitting a
small cylinder which surrounds the rod; this cylinder is connected with the rudder
mechanism, as hereinafter described.

page_text: The wheel valve has one solid rod extending through the valve chest, and has a
connection by rod or otherwise to the wheel.
The wheel valve covers both the pressure and exhaust ports in the rudder valve.
The valve chest, the pipe connecting it to the cylinder or cylinders at the rudder
head, and the cylinder, are always filled with liquid. By the act of uncovering the
pressure ports this liquid is placed under the full pressure of the pumps, and the
pistons in the cylinder at the rudder head are moved in one direction. The act of
closing the pressure port and uncovering the exhaust port causes the pistons in the
main cylinders to move in the other direction, and discharges the liquid into the
exhaust chamber, and thence into the supply tank. This uncovering of the pressure
and exhaust ports, thereby starting the mechanism into action, is the function of
the wheel valve, which receives its motion from the wheel.
The rudder valve receives its motion from the mechanism at the rudder head in
the following manner :-
It is absolutely essential that any movement of the rudder should cause a
corresponding movement of the rudder valve. This can be effected by means of a
series of metal rods, or by a cylinder containing a piston inserted in the pipe
connecting the valve chest and cylinder at the rudder head, or (and preferably) by a
small independent pipe leading from the rudder head to the small cylinder at the
valve chest at the pump. One end of this pipe is connected to a small supple-
mentary cylinder containing a plunger worked by the main ram or cross head at
the rudder head; the other end of this pipe terminates at the small cylinder, before
mentioned, at the valve chest. The small pipe leading from the rudder head
enters one end of this cylinder; the other end has a connection with the main
pressure and exhaust pipe leading from the valve chest. When the plunger at the
rudder head is withdrawn from the cylinder to the extent of its stroke, and the
piston on the rudder valve rod is at the outer end of the cylinder, then the
connecting pipe and the supplementary cylinder at the rudder head are filled with
liquid and closed. This liquid thereafter remains without change in quantity
except from loss by leakage, which loss must be compensated for by supplying
fresh liquid from time to time. When the plunger is withdrawn, as before
described, the piston or ram in the main cylinder is at the end of its stroke; any
motion of the ram causes a corresponding motion to the plunger, forcing the liquid
out of the supplementary cylinder through the pipe, and against the piston on the
valve rod, which in turn moves the valve a corresponding distance. The reverse
movement of the ram at the rudder head again withdraws the plunger, and the
liquid under pressure from the valve chest forces the piston back to the starting
point, and in this manner the piston on the valve rod always moves in one direction
or the other corresponding to the movement at the rudder head.
The valve mechanism, hereinbefore described, is also applicable to steam steering
gear.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joseph Knight Kilbourn and George Fossick in the Great Seal
Patent Office on the 15th July 1881.
JOSEPH KNIGHT KILBOURN, of Brixton, in the County of Surrey, and GEORGE
FOSSICK, of Stockton on Tees, in the County of Durham. " IMPROVEMENTS IN
STEERING GEAR."
Our said Invention relates partly to certain improvements in that class of
steering gear in which the power is transmitted to the rudder stem by the use of a
quick threaded screw or spiral bolt; also to improvements in that class of steering
gear in which the tiller held rigid by an uncompressible liquid; also to improve-
ments that may be applied to any system of steering-gear wherein it is desirable
to have a dual action in the valve gear controlling the motive power, that is to
say, in which one part of this action, videlicet, namely, the starting motion, is
derived from the steering wheel or lever, and the other part, videlicet, an automatic
closing motion, is obtained direct from the mechanism which actuates the rudder.
And in order that our said Invention may be fully understood we shall now
proceed to describe the same, and for that purpose shall refer to the several Figures
on the annexed Sheets of Drawings, the same letters of reference indicating corre-
sponding parts in all the Figures.
Figure 1, Sheet 1 of the accompanying Drawings, is a sectional elevation
illustrating a mode of carrying out our said Invention as applied to that class of
steering gear in which the power is transmitted to the rudder stem by the use of a
quick threaded screw or spiral bolt; Figures 2, 3, and 4 are horizontal sections
taken respectively along the lines 1-2, 3-4, and 5-6 (Figure 1); Figure 5 (on
Sheet 2) is a horizontal section illustrating the application of relief springs,
according to our said Invention, to horizontal steering gear having a single
cylinder, and Figure 6 is a transverse vertical section of the same; Figure 7 is a
half plan and half horizontal section illustrating the application of relief springs
to horizontal steering gear having two cylinders; Figure 8 is a detail section
drawn to a larger scale, showing the springs and their connections, corresponding
to the arrangements illustrated both in Figures 5 and 6 and Figure 7; Figures 9
10, and 11 (on Sheet 1) illustrate that part of our said Invention which relates
to the valve gear for controlling the power for working the steering mechanism,
Figure 9 being a longitudinal section of the valve gear, and Figures 10 and 11
cross sections of the same taken respectively along the lines 7-8 and 9-10
(Figure 9).
In the class of steering gear first hereinbefore referred to, that is to say, where
the power is transmitted by the use of a quick threaded screw or spiral bolt, the
severe labour and great wear comes on the nut which turns the screw or spiral
bolt, and the excessive friction is on the surfaces of the parts that sustain the end
thrust of the screw or spiral bolt. Heretofore no adequate provision has been
made to take up this wear or lessen this friction. Now this part of our said
Invention has for its object the obviating of these defects, and this is effected in
the following manner, reference being had to Figures 1 to 4 of the Drawings.
A is the screw or spiral bolt for transmitting motion to the rudder stem B, the
screw or spiral bolt receiving its rotary motion by the longitudinal to and fro
movements of a nonrotating nut C adapted to the screw. According to this part of
our said Invention we make the nut C in segments c, c, (see Figure 2) the number
of which correspond to the number of threads a in the screw or sides to the spiral
bolt. The aggregate of these segments forms a complete circle, the external
surfaces being in the form of a double truncated-cone, as shewn at b, b. The

page_text: segments are held together and in position by a double cross head D, D, bored to
fit the surfaces of the cone at b, b, (Figure 1) and drawn together by strong bolts d.
In the first fitting of the nut the contact edges of the segments may have left
thereon "file spots" c¹, which are subsequently reduced, or may have intervening
strips of thin metal, which are subsequently removed whenever it is desirable to
take up the "lost motion" occasioned by wear, the two parts of the crosshead D, D,
being brought into closer proximity. The obtaining compensation for wear is an
important object of this part of our said Invention, and which is thus effected in
an economical manner.
In order to reduce excessive friction we employ two series of metal balls e, e,
placed between the surfaces E, E', E, of the parts which sustain the head thrust in
both directions; these balls may be of hardened steel or of chilled iron, or other
suitable material of such hardness that the pressure upon them shall not cause
abrasion. It is obvious that in lieu of using balls their equivalents may be
employed, as, for example, conical rollers, whereby the same effect is obtained.
In the example illustrated the power is applied by means of a hydraulic
cylinder F, ram F¹, and crosshead D. This part of our said Invention is however
applicable whether the power is applied by hydraulic agency or otherwise.
In the case of hydraulic steering gear as heretofore constructed adequate
provision has not been made to overcome the excessive rigidity with which the
rudder is held, or relieve the shock caused by heavy seas against the rudder.
According to another part of our said Invention we overcome this difficulty in the
following manner;-In addition to the well known "relief valves," which are
usually located at a point more or less remote from the rudder, we employ an
arrangement of relief springs in very close proximity to the tiller, through which
all the power is transmitted to the rudder stem, and which will in the event of
excessive strain yield to a predetermined extent, and recover again as soon as this
excessive strain is removed. The nearness of these springs to the rudder stem
causes them to give instantaneous relief, thereby acting as a cushion to the tiller or
its substitute.
These relief springs are especially applicable to two modifications of hydraulic
steering gear, which may be respectively designated "vertical" and "horizontal
steering gear." In both modifications either one or two cylinders may be used.
With the vertical, with a single cylinder, the latter is placed directly over the
rudder stem, as shewn in Figure 1. With the vertical, with two cylinders, one
cylinder is placed on each side of the rudder stem. As however in both cases the
arrangement is otherwise similar we shall describe the application of this part
of our said Invention to the vertical apparatus with a single cylinder, reference
being had to Figures 1 and 4 of the Drawings; F is the cylinder, the ram F of
which works a crosshead D; H, H, are the relief springs, the boxes h, h, of which
form part of a disc plate I attached to the screw or spiral bolt A and turning
with it.
This plate forms the coupling which connects the screw or spiral bolt A to the
rudder stem B, the tiller K resting between two or more of the relief springs H, H,
and closing them whenever there is excessive strain upon the rudder.
In the example shewn in our Drawings two springs H, H, act upon the tiller K,
and the rudder stem B is also provided with a supplementary tiller K' upon which
two other springs H, H, act; inasmuch as the springs turn with the screw or spiral
bolt the action of the tiller against the springs is always at the same angle.
Figures 5, 6, and 8, (Sheet 2) illustrate the application of this part of our said
Invention to "horizontal" steering gear having a single cylinder.
The stem F of the ram F' is tubular and contains the springs H, H. The
connection from the rams to the rudder stem may be made in various ways, but
we prefer to make this connection, as shewn in the Drawing, by means of a
rack L on the rain, and a pinion L' on the rudder stem B. By this method the
power is always applied at right angles to the resistance.
The rack is tubular, forming part of a sleeve which surrounds the ram stem F³,

page_text: and is connected to it by a pin g in such a manner that the rack sleeve is allowed a
longitudinal play on the ram stem, as shewn at f, f, (Figure 8) to the extent of the
relief motion obtained from the springs, whilst the pin g is caused to act without
play upon the blocks h which compress the springs. Under this arrangement any
excessive strain or blow upon the rudder is transmitted through the pinion L¹ to
the rack L, and thence to one or other of the springs H (according to the direction
from which the strain or blow proceeds), whereby the said spring is compressed, so
as by cushioning the strain or blow to afford the requisite relief, the spring
returning to its normal position as soon as the rudder is relieved from the excessive
strain. The springs are normally maintained at a uniform neutral point by means
of a rod h¹, the extremity h² of which separates the two blocks h. In order to
insure greater strength, together with smoothness of action, both rack and pinion
are shrouded to the pitch line at i, i, and with a view to maintain the pinion and
rack in gear a vertical roller M is placed against the back of the rack L, and
another M against the opposite side of the pinion resting against the shrouding,
the two being secured together by a cap plate N.
When two horizontal cylinders are used they form part of or are secured to one
and the same bed plate O, as shewn in Figure 7, at opposite sides of the rudder
stem B. As the general arrangement of the springs is the same as in the
modification illustrated in Figures 5 and 6 the view, Figure 7, will be understood
from the description herein before given without further explanation.
It should be understood that the different modifications of hydraulic steering-
gear hereinbefore described refer to the systems using differential pistons as rams,
that is to say, a piston or ram which has one face of equal area to the cylinder, and
the other of, say, one half of the area of the cylinder. In this case the pressure is
constant on the smaller face of the ram, whilst the larger face is alternately
subjected to and relieved from pressure. This differential ram is however not
essential to the application of our said Invention, but is preferred, and the
description of different parts of the Invention herein before described has reference
to this particular class.
Another part of our said Invention relates to the "valve gear "which controls
the power for working the steering mechanism, and is applicable to steam steering
as well as to hydraulic gear, but in order to avoid confusion we shall describe it
as applied to a hydraulic arrangement. In all successful systems of steering other
than by manual labour the steersman or "man at the wheel" has only to set in
motion the mechanism which does the work, and to determine by the extent of
movement he gives to wheel or lever the exact position to which the rudder is to
be set. This mechanism so started is stopped by its own action whenever the
rudder arrives at the indicated point. In other words there should always be a
fixed relation between the position of the wheel or its substitute and the position of
the rudder, and the 2 parts should be so arranged that the first cannot be moved
without causing a corresponding movement of, the rudder. This part of our said
Invention has for its object obtaining such an arrangement of equilibrium valves
as insures easy movement, certainty of action, and great simplicity of construction.
This object is effected in the following manner, reference being had chiefly to
Figures 9, 10 and 11 (Sheet 1) of the Drawings, and also partly to Figures 5 and 7
(Sheet 2) of the Drawings:-In a valve chest P (Figures 9, 10, and 11) located on
or near the pumps, and connected by a pipe k to the cylinder or cylinders F herein-
before referred to at the rudder bead we provide two valves, videlicet, one l, which
for convenience, we term the "rudder valve," the other m having its seat on the
rudder valve, and which we term the "wheel valve." Each of these two valves
has an entirely independent movement. The rudder valve has two compartments
n, n', from which are ports or passages o, o', covered by the wheel valve m. At
each end of the rudder valve is a tubular valve rod p or p', one end of each
opening into one of the before named compartments n, n'. One of these valve
rods, videlicet, that p¹ extends through the chest p into the chamber Q filled with a
liquid under constant pressure from the pumps, the other rod p extending through a

page_text: supplementary chamber R called the exhaust chest with which the tubular rod is in
communication by means of openings q. On the end of this valve rod is a piston S
fitting a small cylinder T which surrounds the rod, this cylinder is connected with
the rudder mechanism, as hereinafter described.
The wheel valve m has one solid rod r extending through the valve chest, and
has a connection by rod or otherwise to the wheel. The wheel valve in its normal
position, as indicated in the Drawing, covers both the ports o, o¹, in the rudder valve,
the port o¹ being the pressure port, and the port o the exhaust port. The valve
chest P, the pipe k connecting it to the cylinder or cylinders F at the rudder head,
and the said cylinder or cylinders are always filled with liquid. By the act of
uncovering the pressure port o¹ this liquid is placed under the full pressure of the
pumps, and the ram or rams F', in the cylinder or cylinders F are moved in one
direction. When the pressure port o¹ is closed the act of uncovering the exhaust
port o causes the ram or rams in the cylinder or cylinders F to move in the other
direction and discharges the liquid into the exhaust chamber R, and thence through a
pipe sinto the supply tank. This uncovering of the pressure and exhaust ports,
thereby starting the mechanism into action, is the function of the wheel valve which
receives its motion from the wheel.
With respect to the motion of the rudder valve l, it is absolutely essential that
any movement of the rudder should cause a corresponding movement of the rudder
valve. This can be effected by means of a series of metal rods or by a cylinder
containing a piston inserted in the pipe k connecting the valve chest P and the
cylinder or cylinders F at the rudder head, but we prefer to employ the arrange-
ment illustrated in the Drawing, and next hereinafter described.
The small cylinder T at the valve chest P is connected by a pipe U to a small
supplementary cylinder V, Figures 5 and 7, containing a plunger W, which is
worked by the main ram or one of the main rams F¹ (Figures 5 and 7) or by the
crosshead D (Figure 1) although not shown in the last mentioned Figure.
In first preparing the apparatus for operation the plunger W is withdrawn from
the cylinder V to the extent of its stroke and the piston S is placed at the outer
end of the cylinder T, the connecting pipe U and the cylinder V are then filled with
liquid and closed. This liquid thereafter remains without change in quantity
except from loss by leakage, which loss must be compensated for by supplying fresh
liquid from time to time, for which purpose a pipe X is provided.
When the plunger W is withdrawn as before described the ram F¹ in the main
cylinder F is at the end of its stroke. Any motion of the ram then causes a
corresponding motion to the plunger W forcing the liquid out of the cylinder V
through the pipe U and against the piston S on the valve rod P, which in turn
moves the valve la corresponding distance. The reverse movement of the ram F¹
at the rudder head again withdraws the plunger W and the liquid under pressure
from the valve chest P forces the piston S back to the starting point, and in this
manner the pistons S on the valve rod p always moves in one direction or the other,
corresponding to the movement at the rudder head.
Having now described and particularly ascertained the nature of our said
Invention, and the manner in which the same is or may be used or carried into
effect, we would observe in conclusion that what we consider to be novel and original,
and therefore claim as the Invention secured to us by the herein before in part
recited Letters Patent is,-
First. In steering gear in which the power is transmitted to the rudder by means
of a screw or spiral bolt, constructing the nut which turns the screw or spiral bolts
in segments, substantially as and for the purpose hereinbefore described.
Second. In steering gear in which the power is transmitted to the rudder by
means of a screw or spiral bolt, constructing the nut which turns the screw or spiral
bolt in segments with their external surfaces in the form of a double truncated
cone, substantially as and for the purposes hereinbefore described.
Third. In steering gear in which the power is transmitted to the rudder by means
of a screw or spiral bolt the employment of antifriction balls or their equivalents

page_text: arranged as herein set forth for receiving the end thrust in both directions, substan-
tially as hereinbefore described.
Fourth. In bydraulic steering gear the employment of relief springs in the
connection between the actuating part or parts and the rudder, substantially as and
for the purpose hereinbefore described.
Fifth. In hydraulic steering gear the peculiar arrangements of relief springs and
the combination of the same with the actuating part or parts and with the rudder
substantially as and for the purpose herein before described and as illustrated in
Figures 1 and 4, and Figures 5, 6, 7, and 8 of the accompanying Drawings.
Sixth. In steering gear in which motion is transmitted from the actuating part
or parts to the rudder through the intervention of a rack or racks and pinion, as
herein set forth, shrouding the rack or racks and pinion to the pitch line and
employing in combination therewith rollers maintained in contact with the rack
and shrouding or with the racks by a cap plate or connection, substantially as
herein before described.
Seventh. In the valvular apparatus of steering gear in which the main valve is
opened by hand and closed automatically, the combination of the wheel valve m, the
rudder or main valve with its tubular spindles p, p¹, the pressure chamber Q, the
exhaust chamber R, and a connection with the main ram or rams, substantially as
herein before described.
Eighth. In the valvular apparatus of steering gear in which the main valve is
opened by hand and closed automatically, the combination with the wheel valve,
the rudder or main valve with its tubular spindles, and the pressure and exhaust
chambers arranged as herein set forth of the piston S connected to the rudder or
main valve and working in the cylinder T which is capable of being placed at one
end in communication with the pressure and exhaust passages, and at its other
end communicates by a pipe containing liquid with the cylinder V, the plunger W
of which is connected to the main ram, the whole of the parts being constructed,
arranged, and combined together so as to operate substantially as hereinbefore
described and illustrated in the accompanying Drawings.
Ninth. The general arrangements and combination of parts forming steering
gear, substantially as herein before described and illustrated in Figures 1, 2, 3, 4,
and Figures 5, 6, 7 and 8, of the accompanying Drawings.
In witness whereof, we, the said Joseph Knight Kilbourn and George
Fossick, have to this our Specification set our hands and seals, this
Eleventh day of July, One thousand eight hundred and eighty one.