U.S. patent number 3,760,759 [Application Number 05/122,772] was granted by the patent office on 1973-09-25 for stabilising apparatus for ships and the like.
Invention is credited to Thomas Norman Lang.
United States Patent |
3,760,759 |
Lang |
September 25, 1973 |
STABILISING APPARATUS FOR SHIPS AND THE LIKE
Abstract
A ship stabilising apparatus comprising means to stabilise a
ship by the tilting of fins extended therefrom, said fins being
operable to apply anti-rolling forces, anti-pitching forces or
forces which are an integration of anti-rolling forces and
anti-pitching forces, said forces being modulated to suit the
ship's immediate stabilising requirements and said tilting to be
timed to avoid the application of pro-oscillatory forces to the
ship and said fins in special circumstances being controllable to
apply continuously to the ship about its rolling axis a clockwise
or an anti-clockwise torque.
Inventors: |
Lang; Thomas Norman (Hampton,
Victoria, AU) |
Family
ID: |
3764625 |
Appl.
No.: |
05/122,772 |
Filed: |
March 10, 1971 |
Foreign Application Priority Data
Current U.S.
Class: |
114/126 |
Current CPC
Class: |
B63B
39/06 (20130101) |
Current International
Class: |
B63B
39/00 (20060101); B63B 39/06 (20060101); B63b
039/06 () |
Field of
Search: |
;114/121,122,126 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Halvosa; George E. A.
Assistant Examiner: Basinger; S. D.
Claims
I claim:
1. In a ship stabilizing apparatus comprising a tiltable fin, an
oscillatory sensor, a reactor mechanism controlled by said sensor
and fin operating mechanism operably connected between said reactor
mechanism and said fin; said sensor including an inertial member
mounted so as to oscillate responsively to oscillations of the
ship, inertial means to which the inertial member is drive
connected, first and second valvular means drive connected to the
inertial means, potential controlling means of said reactor
mechanism to which a modulated supply of motive liquid is provided
by operation of said first valvular means, a motive cylinder of
said reactor mechanism to which motive liquid is supplied, piston
valve means to control the supply of motive liquid to the said
motive cylinder, an actuating piston in the said motive cylinder
moved by the motive liquid whereby anti-oscillatory efforts are
applied to the fin operating mechanism, said potential controlling
means being adapted to regulate the amount of movement of the said
actuating piston in accordance with the ship's angular displacement
and angular velocity of oscillation, said fin operating mechanism
including drive means connected between said actuating piston and
the fin and operable on movement of the actuating piston to
transmit tilting movement to the fin.
2. The combination of claim 1 wherein braking means are provided on
the drive from the inertial member so as to apply a braking effect
on said inertial member at all but low angular velocities of
oscillation, said braking effect being substantially porportional
to said angular velocities and being adjusted to cause the
oscillatory periods of the inertial member and of the ship to end
coincidentally, whereby the action of the reactor will be regulated
for correctly timing the reversal of the tilting of a fin.
3. The combination of claim 1 wherein manually operable valvular
means are provided to supply motive liquid to said potential
controlling means either as an alternative source to the modulated
supply or to augment said modulated supply.
4. The combination of claim 1, including two piston rods attached
to the said actuating piston, two master cylinders located in
tandem relationship with said motive cylinder, and a piston in each
of the two master cylinders connected with said piston in said
motive cylinder by said piston rods.
5. A ship stabilizing apparatus according to claim 1, including two
master cylinders for producing anti-oscillatory efforts a motive
cylinder for activating each said master cylinder, a
potential-controlling valvular means for regulating said motive
cylinder to transmit anti-oscillatory efforts to a respective fin
operating mechansim.
6. The combination of claim 1, wherein said potential controlling
means comprises at least one cylinder, a spring biased piston
housed in said cylinder, a pair of piston valves operably connected
to said spring biased piston and associated with said motive
cylinder so as to regulate the retention of liquid in either end of
the cylinder and thereby control the length of stroke of the
actuating piston whereby the potential of anti-oscillatory efforts
transmitted to the fin operating mechanism is proportional to the
immediate anti-oscillatory requirements of the ship.
7. In a ship stabilizing apparatus comprising a tiltable fin, an
oscillatory sensor, a reactor mechanism controlled by the said
sensor, and fin operating mechanism operably connected between said
reactor mechanism and said fin; said sensor including an inertial
member mounted so as to oscillate responsively to oscillations of
the ship, inertial means to which the inertial member is drive
connected, valvular means drive connected to the inertial means, a
piston activated through the said inertial means, a piston valve on
said piston operable to control the supply of motive liquid, a
motive cylinder of said reactor mechanism to which the motive
liquid is supplied, an actuating piston in the said motive cylinder
moved by the motive liquid whereby anti-oscillatory efforts are
applied to the said fin operating mechanism, which includes drive
means connected between said actuating piston and the fin and
operable on movement of the actuating piston to transmit tilting
movement to the fin.
8. A ship stabilizing apparatus according to claim 1, including a
first reactor controlling cylinder connected to the second valvular
means, a piston housed in the first reactor controlling cylinder, a
piston rod on which the piston is mounted, a second reactor
controlling cylinder, a piston valve means in the said second
reactor controlling cylinder and connected to the piston rod which
is subject at either end thereof to gas pressure so as to arrest
the movement of said piston valve until gas exhaust valve means
automatically operable by said inertial member when the angular
velocity of the ship's oscillation approaches a zero value exhausts
gas from one end of said piston valve and allows the piston valve
to complete its movement to reverse the supply of motive liquid to
the motive cylinder of the reactor and thereby reverse the
anti-oscillatory effort applied to the fin operating mechanism at
the commencement of an anticipatory period of oscillation.
9. The combination of claim 8 wherein manually operable valvular
means are provided to exhaust the pressurized gas from the ends of
the second reactor controlling cylinder.
10. The combination of claim 8, wherein said piston of the first
reactor controlling cylinder activates said piston valve through a
resilient means.
11. A ship stabilizing apparatus according to claim 7, including a
similarly operable second oscillatory sensor and a second similarly
operable reactor mechanism, one sensor and reactor mechanism being
responsive to rolling oscillations and the other sensor and reactor
mechanism being responsive to pitching oscillations, both reactors
being operable to transmit their respective efforts to said fin
operating mechanism for integration thereby into one stabilizing
effort.
12. A ship stabilizing apparatus according to claim 11, including a
plurality of fins, a fin operating mechanism operatively connected
to each of said fins and to both of the said reactor
mechanisms.
13. The combination of claim 12, including means to override the
actions of the said first and second oscillatory sensors, means to
convert the normal effort delivered by said reactor mechanism
responsive to pitching oscillations to the operating mechanism of
one fin from positive to negative and the reverse, and manually
operable means whereby each said reactor mechanism applies a
positive effort to the operating mechanism of a first fin and a
negative effort to the operating mechanism of a second fin, said
manually operable means also applying said efforts to said
respective fins in reverse manner.
14. The combination of claim 11, wherein said drive means of the
fin operating mechanism comprises a movable member connected to the
fin by linkage and consisting of a body having a shaft rotatable
therein and lever means attached to said shaft, said lever means
being operable by the efforts transmitted by the actuating pistons
of the reactors to rotate said shaft and move bodily said movable
member and thereby transmit tilting movement to the fin.
15. The combination of claim 7 including a first reactor
controlling cylinder connected to a valvular means operated by said
sensor, a piston housed in said first reactor controlling cylinder
and mounted on a piston rod, a second reactor controlling cylinder
having a piston valve therein to which the said piston rod is
connected, the piston valve being operable to compress gas at
either end of the second reactor controlling cylinder so as to
arrest the movement of said piston valve, gas exhaust means
automatically operable by said inertial member when the angular
velocity of the ship's oscillation approaches a zero value, the
piston valve movement being arrested until the said gas exhaust
valve means exhausts gas from one end of said second reactor
controlling cylinder and allows the piston valve to complete its
movement to reverse the supply of motive liquid to the motive
cylinder of the reactor and thereby reverse the anti-oscillatory
effort applied to the fin operating mechanism at the commencement
of an anticipatory period of oscillation.
16. The combination of claim 7, wherein the fin is slidably mounted
in a fin carrier pivotally housed in a sea chest in the ship's
side, and including controlling arms for operating the fin carrier
connected to said drive means, and adjustment means for slidably
moving said fin in said fin carrier between a fully extended
position and fully retracted position at all angles of tilt of the
fin carrier, said fin having at least one supporting stem in
parallel relationship to the axis of tilt.
17. A ship stabilizing apparatus according to claim 16, wherein the
adjustment means comprises at least one screw-threaded rod on said
fin, internally screw-threaded gear means engageable with said
screw-threaded rod, and a reversible motor drive connected to the
gear means.
18. The combination of claim 17 and further comprising at least one
tongue on said fin and housed in said fin carrier for slidable
movement therein.
Description
BACKGROUND OF THE INVENTION
The invention relates to means whereby rolling and pitching, being
oscillatory motions of a ship, are to be minimised; and also means
to apply to the ship torsional couples which will oppose the ship's
tendency to swing outwards whilst turning.
Rolling occurs about a rolling axis which lies in a fore-and-aft
direction in a ship and is a motion in which momentum accumulates
from consecutive waves, causing the ship to overtravel such effects
as can be produced by individual waves, and inertial members as
hereinafter described which roll or pitch in concert with the ship
will tend to overtravel for the same reason. Pitching is similar to
rolling in that great momentum accumulates, but differs in that
independently of rolling, it acts about a pitching axis which lies
across the ship.
To neutralise the said great momenta in a very brief time by the
transference of great volumes of water ballast is not practicable;
the sudden movements of heavy weights is too cumbersome and
dangerous; and only fine which, controlled and motivated by
entirely mechanical means, reverse their anti-oscillatory efforts
very quickly, thereby deflecting great quantities of the ambient
water upward or downward are herein regarded as acceptable. When a
fin's leading edge is raised the said water applies a lifting force
to that fin and that fin's setting is referred to as positive tilt;
and the force which causes or tends to cause that setting is
hereinafter referred to as a positive effort. To enable a fin to
oppose an oscillatory motion of the ship substantially during the
entire period of each oscillation the application of an
anti-oscillatory effort must commence before the previous
oscillation ends, and must be half completed at the instant when
that oscillation ends. This timing obviates the production by the
respective fin of pro-oscillatory efforts which would detract from
the efficiency of the apparatus and cause much power-wasting
turbulence.
Whilst a ship is moving slowly over critically shallow water it
must have fins of sufficient area and angle of tilt to achieve
stabilisation, but such fins or such setting might be excessive for
application when the ship is moving at its usual speed in the open
sea.
To obtain the best locations for fins the following facts requre
consideration. Fins, if extended from near the bows can be operated
to reducce rolling or pitching or both, and might be essential to a
very large ship although they are prone to damage; if extended from
amidships they can be operated only to reduce rolling, but if
extended from near the stern they can be operated to reduce both
rolling and pitching, are reasonably safe from damage, and need not
add greatly to the turbulence inevitably caused by the rudder and
propellers.
In conventional fin design there are some objectionable features.
As a first instance a fin is often supported by a single shaft and
has a considerable extended length which creates a great bending
moment, necessitating a large supporting shaft which, in
combination with the fin having a moderate fore-and-aft dimension
and usually a tilted trailing flap also, requires a fin having a
section which is inevitably very inefficient in a hydro-dynamical
sense, which causes a heavy drag even when untilted, and which
cannot produce an appreciable stabilising force until a high ship's
speed and angle of tilt have been applied, and such a fin in all
circumstances of operation will cause inordinate drag and
turbulence. As a second instance, to reduce pitching, many modern
ships are built with a bulbous bow to reduce pitching thereby
losing at all times and speeds much of the benefit they should have
received from pure streamlining.
It is an object of the present invention to provide a ship
stabilising apparatus which overcomes the above-described
disadvantages of the prior art and provides for more effective
stabilisation of a ship during all speed conditions and angles of
tilt of the fin or fins.
Other objects of the invention are:
(a) to apply to the fin or fins both anti-rolling and anti-pitching
efforts in an integrated form that will cause minimal turbulence;
(b) to apply the said efforts at the commencement of an
anticipatory period, such period being the time required by the fin
operating mechanism to half complete its effort-reversing action,
by which timing the current anti-oscillatory effort will cease when
the current oscillation ceases, thus obviating the possibility of a
pro-oscillatory effort being applied to said fin whereby much power
wasting turbulence would be casued; and (c) to provide a fin having
a minimal bending moment at its points of support.
According to the invention there is provided a ship stabilising
apparatus comprising at least one fin, an oscillating sensor, a
reactor controlled by said sensor, and a fin operating mechanism
operably connected between said reactor and said fin, said sensor
including an inertial member mounted so as to oscillate
responsively to oscillations of the ship, said inertial member
being operable to control a supply of motive liquid to potential
controlling means of said reactor and a supply of motive liquid to
motive means of said reactor for movement of an actuating means
therein, said potential controlling means being adapted to regulate
the amount of movement of said actuating means and said actuating
means being adapted to transmit anti-oscillatory efforts to the fin
operating mechanism.
The apparatus of the invention may also include a further similarly
operable sensor and similarly operable reactor, one sensor and
reactor being responsive to rolling oscillations and the other
sensor and reactor being responsive to pitching oscillations, both
reactors being operable to transmit their respective efforts to
said fin operating mechanism for integration thereby into one
stabilising effort.
The fin or fins may be of longer dimension along the ship and where
two fins are used, one on either side of the ship, each fin is
operatively connected to a fin operating mechanism, each fin
operating mechanism being connected to both reactors.
The novel features which are considered as characteristic of the
invention are set forth in particular in the appended claims, and
in order that the invention and its manner of performance will be
more fully described reference will now be made to embodiments of
the invention as illustrated in the accompanying drawings.
FIGS. 1A and 1B are a flow diagram showing the application of
stabilising efforts to a ship whilst oscillating at a time before
mid-roll and mid-pitch;
FIG. 2 is a part-sectional elevation through a roll sensor of the
invention, taken along line 2--2 of FIG. 4;
FIG. 3 is a part-sectional elevation through the roll sensor taken
along line 3--3 of FIG. 2;
FIG. 4 is a fragmentary section through the inertial member of the
sensor taken along the line 4--4 of FIG. 2;
FIG. 5 is a fragmentary section of a rotary valve taken along the
lines 5--5 of FIG. 3;
FIG. 6 is a similar section to FIG. 5 taken along the line 6--6 of
FIG. 3;
FIG. 7 is a fragmentary section in plan taken along the line 7--7
of FIG. 3;
FIG. 8 is a part-sectional plan of a reactor of the invention along
the line 8--8 of FIG. 9;
FIG. 9 is a sectional elevation taken along the line 9--9 of FIG.
8;
FIG. 10 is a sectional elevation of a fin and its operating
mechanism taken along the line 10--10 of FIG. 13;
FIGS. 11A, 11B and 11C illustrate the outlines of ships fitted with
stabilising fins;
FIG. 12 is a sectional elevation taken along the line 12--12 of
FIG. 9;
FIG. 13 is a part-sectional view taken along the line 13--13 of
FIG. 10;
FIG. 14 is a sectional view taken along the line 14--14 of FIG.
13;
FIG. 15 is a sectional view taken along the line 15--15 of FIG.
13;
FIG. 16 is a sectional view of a first modified form of reactor;
and
FIG. 17 is a sectional view of a second modified form of
reactor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
To find the most suitable positions at which to install fins on a
ship FIGS. 11A, 11B and 11C show the outlines of ships which are
rolling to starboard whilst their sterns are rising. Ships 1 and 6
have anti-rolling fins 2, 3, 7 and 8 of conventional outline, and
similar anti-pitching fins 4, 5, 9 and 10; and necessarily the fins
3 and 8 would be positively tilted, whilst the remaining fins would
be negatively tilted, and so both ships 1 and 6 would have on their
starboard side two oppositely tilted fins thereby causing much
turbulence and wastage of power. However, by integrating the
efforts as applied to the fins 8 and 10 and applying the resultant
tilt to a single fin such as fin 10, that fin's tilt would
approximate to zero and the wastage of power thereat would be
obviated; and by similarly integrating the efforts as applied to
the fins 7 and 9 and applying the resultant tilt to a single fin
such as fin 9, that fin would apply negative tilt to the full
extent required to oppose both rolling and pitching at that
position at that time.
FIG. 11C shows the location of fins in the preferred arrangement
wherein a ship 11 has a port fin 12 with a leading edge 12A, a
sea-chest 14, and a starboard fin 13 with a leading edge 13A and a
sea-chest 15. The preferred fins 12 and 13 are substantially planar
in form and rectangular in outline, or may be curved to conform to
the surface of the ship, and their sea-chests 14 and 15 are flush
or streamlined with the surface of the ship.
The preferred apparatus for controlling both roll and pitch of a
ship consists of six pipe connected mechanisms; a roll sensor and a
pitch sensor each having and controlling a reactor; a port and a
starboard fin each having means to receive and apply anti-rolling
or anti-pitching efforts to tilt the fin suitably, and means to
receive both types of effort simultaneously, to integrate them, and
so to tilt the fin.
The roll sensor, (FIGS. 2 and 3) has an inertial member 16
consisting of an air-filled annulus which has an attached weight
16A, and is mounted on two identical arms 17, (FIG. 4), which are
mounted on a central member 18 fixedly mounted on a driving shaft
19 which is rotatably mounted in a liquid filled casing 20 in which
the inertial member 16 being, with the associated members of
suitable mass, has zero buoyancy. The driving shaft 19 is located
in parallel relationship with, and preferably close to the ship's
rolling axis, allowing the inertial member 16 with minimal friction
to roll in concert with the rolling of the ship. The member 16
being gimbal mounted as explained, can also oscillate as shown in
FIG. 2 about the arms 17 in response to the ship's pitching, such
action being resisted by two side rods 21 which are pivotally
mounted as shown in FIG. 2, and which mount springs 22 which return
the member 16 to its normal position after pitching.
Drive from the shaft 19 passes to a sprocket wheel 23, a driving
chain 24, a sprocket wheel 25, a counter-shaft 26, and gear wheels
27 and 28 to rotate a sleeve 29 which is internally splined and
houses a splined spindle 30. Light flyballs 31, (FIG. 2), are
linked to the sleeve 29 and to a collar 32 mounted on the spindle
30. As shown in FIG. 2 the ship's rolling has caused the flyballs
31 to rotate and swing outward thereby lowering the spindle 30
against pressure exerted by a spring 33. The spindle has a first
annular passage 30A and a second annular passage 30B, (FIG. 3), and
passes through a housing 34 mounted on the casing 20. The housing
has two passages 34C and 34D in opposite relationship; and also has
two passages 34B and 34A which are also in opposite relationship.
The passage 30B is located on a plane above the passages 34C and
34D whilst the flyballs 31 are inactive, but when they rotate the
passage 30B lowers and allows motive liquid to flow through the
passages 34C, 30B and 34D to the roll reactor (FIGS. 3 and 8), the
rate of flow being modulated by the passage 30B which, being of
varying depth as shown, allows an increasing rate of flow when the
angular velocity of rolling increases, thereby passing to the
reactor a volume of fluid proportional to the stabilising effort
such as is instantaneously required.
Mounted on the shaft 19 a brake drum 35 (FIGS. 3 and 7) has a
geared section 35A by which drive passes to a step-up gear 36
mounted on a first rotary valve 37, (FIG. 3), which has two
identical arcuate passages 37A and 37B, (FIGS. 1B, 5 and 6) and is
mounted in a housing 39, said housing having two passages 38A and
38B connected respectively to pipes 127 and 129, (FIG. 1B). As
shown in FIG. 3 a brake band 39, pivotally mounted at one end on a
boss 40, has at its other end an oval hole 39A through which the
spindle 30 passes. When the flyballs 31 are idle a collar 41 holds
the band 39 free of the drum 35, but when the flyballs 31 rotate
the spindle 30 descends and a collar 42 mounted thereon compresses
a weak spring 43 whereby the brake band 39 applies to the brake
drum 35 sufficient braking effect to obviate overtravel of the
inertial member 16 and so bring it to rest at the instant when the
current roll ends.
The roll reactor, (FIGS. 8, 9 and 12), has a body 44 which is
spaced by rods 45 from a motive cylinder 46 having a piston 47 with
an extended piston rod 48 which mounts a cruciform crosshead 49 and
is housed in the body 44. Two biasing springs 48A and 48B mounted
on the piston rod 48 abut the cross head 49 and respectively the
motive cylinder 46 and the body 44, and said springs, acting
through the crosshead 49 and the piston rod 48, centralize the
piston 47 in the cylinder 46". In the body 44, a first
potential-controlling cylinder 44A has a piston 50 which is
contacted by a buffer spring 51 and is attached to an extended
piston rod 52 which has an annular passage 52A thereon and is
associated with a housing 46A, a channel 46B, a passage 46C, a
collar 53, a plurality of slots 46D in the cylinder 46 and a
cylinder cover 44B. A second potential-controlling cylinder 44C is
similar to the said first cylinder 44A having a piston, a piston
rod 54 having an annular passage 54A and is associated with a
passage 46E, a plurality of slots 46F in the cylinder 46, and a
buffer spring 55. Both rods 52 and 54 are linked to an equalising
lever 56 by links 57, and movement of the rods 52 and 54 is limited
by the collar 53 engaging an abutment 53A and piston 50 engaging
against the inner face of the cylinder cover 44B.
Whilst the roll reactor is operating normally a control valve 67,
(FIG. 8), remains closed and the modulated liquid supply received
from the passage 34D, (FIG. 3), passes through a pipe 66, a control
valve 68, (FIG. 8), passages 44D and 44E into the
potential-controlling cylinders 44A and 44C, and to one or more
regulating valves such as 69 or 71 which are manually set to
discharge the liquid at a steady rate whilst maintaining in the
said cylinders 44A and 44C pressures which, balanced by the
pressures exerted by the buffer springs 51 and 55, maintain
suitable adjustment of the locations of the passages 52A and 54A to
imprison at each end of each stroke a suitable volume of liquid in
the cylinder 46 whereby the length of stroke of the piston 47 is
controlled. Valves such as 69 and 71 can be located at any near or
remote pipe-connected station and adjustments of their setting
provides an overriding adjustment of the said potential-controlling
action customarily provided by the passage 30B (FIGS. 2 and 3).
Whilst motive liquid is supplied through the pipe 66, an
over-riding adjustment of the supply can be effected by supplying
additional motive liquid through and by the control valve 67 which
can be located at any near or remote pipe-connected station. In the
event of malfunction of the supply delivered through pipe 66, the
valve 68 (FIG. 8) should be closed and the requisite liquid
pressure can then be maintained in the cylinders 44A and 44C by
motive liquid received through and by manual adjustment of the
valve 67.
The body 44 also has a first master cylinder 44F, (FIG. 9), with a
piston and a piston rod which is attached to the cross-head 49, and
also has two passages 44G and 44H through which, by means of two
hydraulic circuits, anti-roll efforts are delivered as will be
explained. These efforts are proportional to the stroke of the
piston 47; to the volume of fluid delivered by the cylinder 44F;
and to the ship's anti-roll efforts as then required for the
starboard fin 13, (FIG. 1B). Similarly a second master cylinder
44J, having a piston, a piston rod, and passage 44K and 44L,
delivers anti-roll efforts to the port fin 12, (FIG. 1A).
The fin operating mechnaism, (FIGS. 10, 13 and 15), of the
starboard fin 13 has an anti-rolling slave cylinder 72, (FIG. 15),
having a piston 73 connected by a piston rod 74 to a crosshead 75
to which are also attached two rack-geared bars 76 which are
slidably housed in the body of the cylinder 72 (FIG. 13). Also
shown in FIG. 15 is an anti-pitching slave cylinder 77 which is
operatively identical with the cylinder 72, having a piston, a
piston rod, a crosshead, and two rack-geared bars 78. Between the
bodies of the cylinders 72 and 77 a movable member 79 is located,
having a housing 81 in which a shaft 82 can rotate, (FIGS. 10 and
15). On each end of the shaft 82 is fixedly mounted a gear 83,
which meshes with the rack-geared bars 76 and 78, (FIG. 15), of
which the bars 76 by their axial position as in FIGS. 1A and 1B
indicate the potential of the anti-rolling effort being then
applied, and the bars 78 indicate the potential of the
anti-pitching effort, so that the position of the shaft 82 and the
movable member 79 indicate the integration of both efforts.
The sea-chest 15 has a body 15A, (FIG. 14), is integral with the
hull of the ship 11 and has an outer cover 15B which has an opening
15C, (FIG. 13), and a split bearing 15D, (FIGS. 10 and 14), and
also has an inner face plate 15E which is strengthened by a number
of ribs 15F which are not part of the invention, but are shown
dotted in FIG. 14. Each of two links 84, (FIG. 13), connects the
movable member 79 to a lever 85 mounted on a shaft 86 which is
rotatably mounted in the inner face plate 15E and the outer cover
15B of the sea chest, (FIG. 14). On each shaft 86 is mounted a
geared sector 87 which meshes with a geared sector 88A of a fin
carrier 88 which has a slot 88B (FIG. 14) on its sea-ward face to
receive the fin 13, and also has a plurality of smooth surfaced
housings such as 88C and 88D and one housing 88E to receive a
pivotal shaft 13D of the fin 13. The fin (FIG. 14), has a leading
edge 13A, two tongues 13B, two stems 13C which have square threads,
and the pivotal shaft 13D which fits rotatably, (a) in the split
bearing 15D, (b) in the housing 88E of the fin carrier, and (c) in
a gear equipped bush 89 which has a register 89A and is housed in
the cover 15E. From a reversible motor 91, (FIG. 10), drive passes
by a chain 92 to a sprocket wheel 93 mounted on the bush 89 and
thence to two gears 94 and 95 (FIG. 14), having registers 94A and
95A and internal square threads to receive the stems 13C so that
the gears 89, 94 and 95, when rotated by the motor 91, extend the
fin from its housings through the opening 15C into the ambient
water, or retract it completely within the outline of the ship
whereby the tongues 13B and the stems 13C retract into watertight
caps or covers 96 and 97. The outline of the opening 15C, (FIG.
13), is such that the fin can be tilted whilst retracted, or partly
or fully extended, by which action the optimum combination of
extension and tilt can be applied to satisfy the ship's immediate
stabilising requirements.
As an alternative form of fin the tongues 13B and their caps 96 may
be omitted.
FIGS. 1A and 1B show the application of stabilising forces as
applied to the ship 11 whilst it is rolling to starboard and the
stern is rising, at a time shortly before mid-roll and mid-pitch.
Motive fluid has passed from the pipe 132, through the passages
37A, 38A, a pipe 127, (which with pipes 128 through 133 is shown on
FIG. 1B), a transverse passage 98A, (which with a similar passage
98B is located in a plunger 98 which is housed in an tilt-fixing
cylinder 99), and thence through a port 100A into a first reactor
controlling cylinder, (which also has a second port 100B), wherein
it has moved to the right a hollow piston 101, a piston rod 102,
and a piston valve 106 in a second reactor controlling cylinder 107
(FIG. 1A), the hollow piston 101 slidably housing a piston rod 102,
which, having a fixed flange 103 thereon is positioned in the
hollow piston 101 by two buffer springs 104 and 105; the piston rod
102 being attached to the piston valve 106, (FIG. 1A), which has
two transverse passages 106A and 106B, the passage 106A being so
located that motive liquid has passed through a pipe 108, a
throttle valve 110, and the passage 106A, into the motive cylinder
46 of the roll reactor and has raised the piston 47 therein and the
pistons in the master cylinders 44F and 44J, thereby causing each
said master cylinder to deliver an anti-roll effort whilst spent
liquid has left the cylinder 46 through a passage 106B. The piston
valve 106 is housed in a second reactor controlling cylinder 107
having ten passages as in FIG. 1A.
As an alternative to the hollow piston 101 a piston of conventional
construction fixedly mounted on a piston rod may be
substituted.
The pitch sensor oscillates about the pitching axis which lies
across the ship and with the pitch reactor is not shown. The motion
of pitching being relatively small in an angular sense a much
larger inertial member and a great or greater step-up gear is
necessary to rotate flyballs such as 31 and a first rotary valve
such as 37 with its associated components as in FIGS. 2 and 3 to
control and regulate the effort-potential of the pitch reactor; and
it is necessary only to show on FIG. 1B that a motive cylinder 109
of the pitch reactor, activated by a pitch sensor, has caused two
master cylinders 111A and 111B to deliver anti-pitching efforts to
two slave cylinders 77 and 116. Delivery of liquid from the master
cylinder 111A has passed through a valve 115 (FIG. 1B), which, in
conjunction with valves 112, 113 and 114, is gang-controlled for a
purpose which will be explained.
FIGS. 1A and 1B show the pipeing means whereby the four master
cylinders deliver efforts each to a respective slave cylinder as
follows; 44F to 72, a positive effort, and in an opposite manner of
application 44J to 117, a negative effort; 111A to 77 and 111B to
116 in a parallel manner of application, both being negative
efforts. It is seen that the former two efforts are applied to the
starboard fin 13 and that they approximately neutralise one another
thereby allowing the fin to occupy its normal position, whilst the
latter two efforts being both negative apply to the port fin 12 a
degree of tilt according to a summation of both efforts. Thus it is
seen that the four said stabilising efforts as applied to the fins
12 and 13 have caused the fins to be set as the ship 11 in the said
circumstances required.
In the preferred embodiment, the fins, being responsive both to a
roll reactor and a pitch reactor, can also respond to either
reactor separately if and when the other reactor is suitably
immobilised, which immobilisation can be effected by a clutching
means which holds in their mid-stroke position the piston in the
slave cylinders which are controlled by the said immobilised
reactor. The throttle valve 110, (FIG. 1A), can be adjusted and
closed to apply the required clutching means to the pistons in the
said slave cylinders.
At the commencement of the next roll the first rotary valve 37
commences to rotate anti-clockwise and after mid-roll it will allow
motive liquid to pass through the passage 37B, the pipe 129, the
passages 98B and 100B into the right hand end of the first
reactor-controlling cylinder 100 wherein it will move the hollow
piston 101 toward the left end of the said cylinder whilst spent
liquid will leave the cylinder through the passage 98A, the pipe
127 and the passage 37A. The said movement of the piston 103 will
compress the spring 105 against the fixed flange 103 and will cause
the piston rod 102 and the piston valve 106 (FIG. 1A) to move
slightly to the left thereby checking the delivery of motive liquid
to, and the discharge of spent liquid from, the motive cylinder 46
of the roll reactor. At the same time the movement of the piston
valve 106 will compress air (or other suitable gas) in the left
hand end of the cylinder 107 and its associated piping, the air
passing through a check valve 120 and a second air controlling
valve 123 and being retained by two check valves 118 and 119, by a
first air control valve 121, and by the spindle 30 being in a
lowered position whilst the flyballs 31 are rotating as on FIG. 4.
Whilst the piston valve 106 moves to the left, air passes into the
cylinder 107 through a check valve 122. These conditions will be
maintained until the rolling velocity of the ship diminishes,
whereby the spindle 30 will rise until, at the commencement of an
anticipatory period, the passage 30A will connect the passages 34B
and 34A thereby releasing the compressed air and tripping the
action of the roll reactor. When the compressed air has been
released as explained the piston valve 106 will move to the left
hand end of the cylinder 107 and thereby release the pressure in
the motive cylinder 46 (see FIG. 1A), thereby enabling a biasing
spring 48A or 48B (see FIGS. 8 and 9) to move the piston 46
whereupon the biasing spring and motive liquid which enters the
motive cylinder 46 through the slots 46D or 46F move the piston 46
to its next position thereby compressing a respective biasing
spring 48B or 48A and reversing the positions of the pistons in the
cylinders 46, 44F and 44J, thereby reversing the efforts that had
been applied to the pistons in the slave cylinders 72 and 117. At
the same time spent liquid will leave the cylinder 46 through the
passage 106A. Anti-pitch efforts will be reversed in identical
manner.
In the event of (a), malfunction of the said means whereby the air
is released; or (b), a high degree of stabilisation being required,
it will be necessary that the second air controlling valve 123,
(FIG. 1A), be closed, and that the first air controlling valve 121,
(which can be located at any near or remote pipe-connected
station), be manually operated to trip the respective reactor.
To oppose the ship's tendency to swing outwards whilst turning it
is necessary to set the fins to apply a suitable counter-torque by
utilising the tilt-fixing cylinder 99 (FIG. 1B) and a second rotary
valve 125 which has a hand lever 125A, two arcuate passages on
different planes, and in its body six pipe connections as shown in
FIG. 1B. The tilt-fixing cylinder 99 has a long key-way 99A, eight
pipe connections or passages, and mounts a retractible boss 124. In
the effort fixing cylinder 99 the plunger 98 has the said passages
98A and 98B, two trough-like passages 98C and 98D, a housing 98G
for the retractible boss 124, and a fixed key 98H which slides in
the key-way 99A. The pitch sensor is similarly equipped, having a
first and a second reactor-controlling cylinder such as 100, and
107, a tilt fixing cylinder such as 99 and associated components;
and is activated by motive liquid passing to and from its tilt
fixing cylinder through the pipes 131 and 133.
To produce a counter-torque to oppose a ship's tendency to swing to
starboard it is necessary:
(a) from tilt-fixing cylinders such as 99 to retract the bosses
such as 124;
(b) to reverse gang-controlled valves 112, 113, 114 and 115 shown
in FIG. 1B, by which operation all positive efforts delivered by
the master cylinder 111A will be converted from positive to
negative and the reverse; and
(c) to rotate a second rotary valve 125 clockwise thereby allowing
motive liquid from an external source to pass through the said
rotary valve and through the pipe 128 into the tilt fixing cylinder
99 thereby causing the plunger 98 to move to the right hand end of
the cylinder 99 thereby displacing the passages 98A and 98B and
invalidating the first rotary valve 37 and allowing motive liquid
to pass from the cylinder 99 through the passage 98C and the port
100A into the cylinder 100 wherein it will hold the piston 101 in
the position shown in FIG. 1B and thereby cause the piston in the
slave cylinder 117 to apply a first negative effort to the port fin
12 whilst the piston in the slave cylinder 72 will apply a first
positive effort to the starboard fin 13, both efforts being as
shown in FIGS. 1A and 1B. At the same time motive liquid released
by the second rotary valve 125 will pass through the pipe 131 to
activate in identical manner in the pitch sensor a plunger such as
98 whereby the associated components of the pitch sensor will cause
the pistons in the cylinders 109, 111A and 111B to be held in their
raised positions as shown in FIG. 1B and the piston in the slave
cylinder 116 will thereby apply a second negative effort to the
port fin 12. At the same time the ganged valves 112 through 115
being reversed allow motive liquid from the cylinder 111A to pass
through the valve 114 and cause the piston in the slave cylinder 77
to apply a second positive effort to the starboard fin 13. Thus it
is seen that both fins would be set to oppose the ship's tendency
to swing to starboard. To oppose the ship's tendency to swing to
port the same procedure is to be followed except that the second
rotary valve 125 is to be rotated anti-clockwise.
A first alternative reactor whose central plane is shown in
sectional plan on FIG. 16 has a stroke-adjustment means identical
with that shown on FIG. 8, and has slots 138 which are similar to
the slots 46D as shown on FIG. 8 but are forked to direct the flow
of motive liquid to twin motive cylinders 139 and 141, whereby a
cylinder 141 activates a master cylinder 143 as shown, and the
cylinder 139 activates a master cylinder 142, (the latter two
cylinders not being shown), and thus each master cylinder delivers
an anti-oscillatory effort as in the preferred embodiment.
A second alternative reactor shown in sectional plan on FIG. 17 has
a motive cylinder 144 having stroke adjustment means identical with
that in the preferred embodiment, but differs therefrom in having
two extended piston rods which activate in tandem relationship two
master cylinders 145 and 146 thereby delivering anti-oscillatory
efforts as in the preferred embodiment.
Pressurised motive liquid is used to control and activate the
preferred apparatus because it gives a positive and very rapid
response and because it enables constant automatic stroke
adjustment to be applied to a piston which reciprocates in a motive
cylinder.
It is to be understood that the invention is not limited to the
matter disclosed but includes all such variations and modifications
of the means described which shall fall within the spirit of the
invention and the scope of the appended claims; for example (a) an
air-surrounded inertial member fixedly or gimbal mounted on a shaft
located in parallel relationship to the axis of oscillation as
described, or (b) a gyroscope with precessional control may be
substituted for the embodiment of the inertial member as
hereinbefore described.
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