Marine propulsion – Screw propeller – With means effecting or facilitating movement of propulsion...
Reexamination Certificate
2003-03-25
2004-09-14
Morano, S. Joseph (Department: 3617)
Marine propulsion
Screw propeller
With means effecting or facilitating movement of propulsion...
C440S06100B, C440S06100B, C114S150000, C114S14400A
Reexamination Certificate
active
06790110
ABSTRACT:
BACKGROUND OF INVENTION
This invention relates to a marine power steering system and more particularly to an improved, compact, high efficiency hydraulically assisted system.
There have been proposed power assisted marine steering systems. These types of systems generally employ hydraulic assist motors that are mechanically coupled to the watercraft steering device to apply a force that assists the manual inputted steering force. These prior art systems have several disadvantages as will become apparent by reference to
FIG. 1
, that shows a conventional type of system now used.
Referring now to
FIG. 1
, a manually operated steering control, such as a steering wheel
11
is mounted in the operator's area of the associated watercraft and its output is connected to a vessel steering device
12
by a Bowden wire actuator, indicated generally at
13
. The watercraft steering device
12
may comprise any known type of watercraft steering device such as a rudder or pivotally supported propulsion device such as an outboard motor or the outboard drive portion of an inboard outboard drive.
The Bowden wire actuator is comprised of an inner, actuating wire
14
and a surrounding protective sheath
15
. One end of the inner wire is connected to the steering wheel
11
and the other end is connected to the watercraft steering device
12
. These connections are of any known type.
A hydraulic assist motor
59
is also connected to the vessel steering device
12
to assist in the steering operation. The assist motor is generally a reciprocating motor comprised of an outer cylinder
17
having a cylinder bore
18
in which a piston
19
is reciprocally mounted to define a pair of fluid chambers
21
and
22
. During steering assist one or the other of the chambers
21
and
22
is pressurized and the fluid from the other is returned to an oil reservoir
23
. How this is done will be described shortly.
A piston rod
24
is connected to the piston
19
at one end and extends through the chamber
22
, externally of the cylinder
17
for connection to the vessel steering device
12
.
The power assist is controlled by controlling the pressurization of either the chamber
21
or
22
from a fluid pump
25
that is continuously driven by an engine
26
which generally is the engine that powers the associated watercraft. The supply and return of the fluid to the motor
26
is controlled by a spool valve, indicated generally at
27
. The spool
28
of the valve
27
is connected to the sheath
15
of the Bowden wire actuator
13
. As is well known, the force applied to the wire
14
from the steering wheel
11
causes a reactive force on the sheath
15
and this force is utilized to actuate the valve spool
28
.
This type of system has a number of disadvantages. For example, the hydraulic pump
25
is constantly driven by the engine
26
while the engine
26
is powering the watercraft, resulting in loss of the engine output. In addition, the hydraulic cylinder
16
and the hydraulic pump
25
are separately installed in the watercraft requiring, complicated hydraulic piping arrangement for connection. This also results in more burdensome installation as well as a risk of foreign matter entering into the hydraulic circuit.
It has been proposed to utilize an electric motor to drive the pump
25
, but this does not simplify the plumbing problems. In addition the motor is operated continuously to insure the availability of hydraulic assist, putting added load on the watercraft electrical system and its batteries. Also it means that the system must be constantly pressurized and this reduces the life of the system.
It is, therefore, a principal object of this invention to provide an improved and simplified water craft steering assist system that has a reduced and simplified hydraulic system and a simplified control and operator therefore.
SUMMARY OF INVENTION
This invention is adapted to be embodied in an assisted marine steering system that is comprised of a manually operated steering control, a watercraft steering device controlling the direction of travel of a watercraft and a manual connection between the manually operated steering control and the watercraft steering device for manually operating the watercraft steering device. A force sensor is provided for sensing the manual force applied to the manually operated steering control. A hydraulic assist motor is coupled to the watercraft steering device for applying a hydraulic assist to the steering operation thereof. Finally, a control varies the amount of hydraulic assist outputted to the watercraft steering device by the hydraulic assist motor in response to the amount of manual force sensed by the force sensor.
REFERENCES:
patent: 3706263 (1972-12-01), Johnson
patent: 4004537 (1977-01-01), Nilsson
patent: 4419084 (1983-12-01), Borst
patent: 4933617 (1990-06-01), Huber et al.
patent: 5031562 (1991-07-01), Nakase et al.
patent: 5057043 (1991-10-01), Sugimoto et al.
patent: 5127856 (1992-07-01), Kabuto et al.
patent: 5146745 (1992-09-01), Doetsch
patent: 5228405 (1993-07-01), Merten
patent: 5240445 (1993-08-01), Aoki et al.
patent: 5244426 (1993-09-01), Miyashita et al.
patent: 5253604 (1993-10-01), Bohlin
patent: 5266060 (1993-11-01), Onoue
patent: 5328394 (1994-07-01), Onoue et al.
patent: 5340341 (1994-08-01), Yoshimura
patent: 5350326 (1994-09-01), Funami et al.
patent: 5387142 (1995-02-01), Takayanagi et al.
patent: 5427555 (1995-06-01), Merten
patent: 5427556 (1995-06-01), Ishikawa et al.
patent: 5447456 (1995-09-01), Nakayasu
patent: 5505641 (1996-04-01), Onoue
patent: 5605109 (1997-02-01), Merten et al.
patent: 56138097 (1981-10-01), None
patent: 58161696 (1983-09-01), None
patent: 03099997 (1991-04-01), None
Beutler Ernest A.
Sogi Kabushiki Kaisha
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