Steering apparatus for outboard motor

Abstract

When a cable-actuated power steering system is used with an outboard motor tiltably supported on a motor mounting pod of a pontoon boat, interference between a valve actuator housing on the end of a cylinder ram of a hydraulic cylinder unit and a side wall of pod is avoided by offsetting the cylinder toward one side wall of the pod so that the actuator housing can move through its full range without interfering with the opposite side wall, and connecting the cable-activated steering rod to a lever on top of the actuator through an L-shaped secondary link that has a first part extending laterally from an end of the steering rod and a second part extending from the first part to the lever in a direction opposite to the direction in which the cylinder ram extends from the cylinder.

Claims

1. A cable-actuated power steering system for a boat propelled by an outboard motor mounted on a transom of a pod having side walls, said outboard motor being pivotable about a substantially vertical steering axis and tiltable about a substantially horizontal tilting axis, the power steering system comprising: a hydraulic cylinder unit comprising a cylinder, a cylinder ram, an actuator housing, an actuator in said actuator housing and a valve mechanism controlled by said actuator, the cylinder ram extending from an interior of the cylinder to the exterior thereof along a cylinder axis substantially parallel to said tilting axis, the cylinder ram being extensible and retractable from said cylinder in the direction of said cylinder axis, the combination of said cylinder and said cylinder ram having first and second opposite ends, one of said first and second opposite ends being an end of the cylinder ram and the other of said first and second opposite ends being an end of the cylinder, said actuator housing being mounted at one of said first and second opposite ends, and said valve mechanism being configured to control the flow of hydraulic fluid to and from the hydraulic cylinder for effecting extension and retraction of said cylinder ram; a steering link connected to the actuator housing and connectible to a steering arm on said pivotable outboard motor to effect pivoting movement of said outboard motor about a substantially vertical steering axis; an actuator arm mounted on the actuator housing, the actuator arm being movable relative to the actuator housing and connected to said valve mechanism whereby movement of the actuator arm relative to the actuator housing controls the valve mechanism to effect extension and retraction of the actuator housing and cylinder ram; a steering rod mounted for movement in a direction substantially parallel to the direction of said tilting axis, said steering rod having a first end connected to said actuator arm to effect said movement of the actuator arm relative to the actuator housing; and a steering cable connectible to a steering helm and connected to said steering rod at a location adjacent a second end of said steering rod opposite from said first end thereof, said steering cable being arranged to effect said movement of the actuator arm in response to operation of said steering helm; wherein said motor is pivotable for tilting about said tilting axis through a range such that at least a part of said actuator housing is located directly between portions of the side walls of said pod; and wherein the connection of said steering rod to the actuator arm through a connecting link includes a first link part that extends laterally from said first end of the steering rod and a second link part that extends from said first link part to said actuator arm in a direction opposite to the direction in which actuator housing moves as said cylinder ram extends from said cylinder.

2. The cable-actuated power steering system of claim 1, wherein said valve mechanism is located in said actuator housing.

3. The cable-actuated power steering system of claim 1, including said pod and wherein the movement of said actuator housing is limited to a region such that, when the outboard motor is tilted, the actuator housing is positioned between said side walls of the pod.

4. The cable-actuated power steering system of claim 1, including said pod and wherein said actuator housing is mounted at said end of the cylinder ram.

5. The cable-actuated power steering system of claim 1, in which said steering rod is mounted for movement through a limited range in said direction substantially parallel to the direction of said tilting axis.

6. The cable-actuated power steering system of claim 1, in which said actuator housing has an upward-facing side and in which said actuator arm is located on said upward-facing side of the actuator housing and movable relative to the actuator housing about a pivot axis extending upward from the upward-facing side of the actuator housing.

7. The cable-actuated power steering system of claim 1, in which said steering rod extends through, and is movable longitudinally in, a tube extending along said tilting axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic side elevational view showing an outboard motor mounted on an engine mounting pod and illustrating the direction in which the outboard motor is tilted;

(2) FIG. 2A is a schematic top plan view of a conventional hydraulic steering system on a pontoon boat, the system having a cylinder that moves on a rod supported between two mounting brackets;

(3) FIG. 2B is a right side elevational view of the steering system of FIG. 2A, showing the direction of movement of the cylinder when the engine is tilted;

(4) FIG. 3A is a schematic top plan view of a cable operated power steering system of the kind ordinarily used on a conventional outboard-propelled boat, but installed on a motor-supporting pod on a pontoon boat;

(5) FIG. 3B is a right-side elevational view of the steering system of FIG. 3A;

(6) FIG. 4A is a schematic top plan view of a cable operated power steering system in accordance with the invention; and

(7) FIG. 4B is right-side elevational view of the steering system of FIG. 3A showing the transom of the pod in cross-section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) As shown in FIG. 1, an outboard motor 10 is attached to the transom of a pontoon boat engine mounting pod 12 by clamp brackets 14. The motor is pivoted about a substantially vertical axis for steering in a swivel bracket 16, and steered by a steering arm 18 operated by a hydraulic mechanism (not shown in FIG. 1) supported by brackets 14. The outboard motor 10 is pivotable for tilting in a direction indicated by arrow C about a substantially horizontal pivot axis, which is also the axis of a tilt tube 22. Typically the motor can be tilted from its normal operating position as shown in FIG. 1 though a range of at least 70. In most cases the tilt angle is between 70 and 90.

(9) In a typical pontoon boat, the outboard motor is steered by a cylinder that travels on a rod in response to the pumping of hydraulic fluid into and out of the cylinder by a control (not shown). The hydraulic fluid fills spaces on opposite sides of an internal piston (not shown) fixed to the rod. FIG. 2A shows a such a rod 24 extending between brackets 26 and 28 and supported by those brackets from clamp brackets 30 on the transom 32 of a pod 34. The brackets are mounted for rotation about a horizontal tilting axis, which is the axis of a tilt tube 35, shown in FIG. 2B. The motor (not shown in FIGS. 2A and 2B) is supported on a shaft 36. The shaft is rotatable in a swivel bracket 38 for steering about a vertical pivot axis. The motor is connected to the traveling cylinder 40 though a steering arm 42 and a link 44.

(10) In FIG. 2A, the steering arm 42 is shown in a position for a full right turn, and the cylinder 40 is at the limit of its travel toward bracket 28. The brackets extend through a distance A, which is less than the spacing B between the side walls of the pod 34. Thus, when the motor is tilted about the tilting axis in the direction indicated by arrow C in FIG. 2B, the rod 24, brackets 26 and 28, and the cylinder 40, can move into the space between the side walls 34 of the pod regardless of the position of the cylinder.

(11) In the case of a cable-activated steering mechanism, steering is controlled by a hydraulic cylinder unit comprising a cylinder, a cylinder ram and an actuator housing that, in most cases, is supported on the end of the cylinder ram and travels with the cylinder ram while the cylinder is fixed to a swivel bracket that support the motor from a transom. (As mentioned previously an alternative, in which the cylinder ram is fixed to the swivel bracket, and the actuator housing and cylinder move relative to the swivel bracket, is also possible.) This type of steering mechanism is used on boats having conventional hulls, but can also be used on pontoon boats if the engine mounting pod is appropriately modified. The steering mechanism is depicted in FIGS. 3A and 3B.

(12) In FIGS. 3A and 3B, the outboard motor (not shown) is supported on a swivel bracket. The outboard motor is steered by a steering arm 45 connected through a link 46 to an actuator housing 48 mounted on an end of a cylinder ram 50 extending from a hydraulic cylinder 52. A valve mechanism within the actuator housing 48 controls the flow of hydraulic fluid supplied by a pump (not shown) to control the rate and direction of movement of the actuator housing. The valve mechanism is in turn controlled by an arm 54 mounted on the actuator housing 48. Arm 54 is pivoted on the actuator housing for movement about a vertical axis. This arm 54 is connected to, and operated by, a steering rod 56, which is guided for longitudinal movement and controlled from a remote steering helm (not shown) by a cable 57 that is movable in a cable sheath 58. The movement of the cylinder ram 50 and the actuator housing follows the movement of the steering rod 56. Relatively little force is required to move the steering rod because the hydraulic cylinder unit (comprising cylinder 52, cylinder ram 50 and actuator housing 48) applies the force that steers the outboard motor. The steering mechanism of FIGS. 3A and 3B is substantially as described in U.S. Pat. No. 9,669,914, granted on Jun. 6, 2017.

(13) In most pontoon boats, the height of the side walls of the engine mounting pod is the same as the height of the transom on the pod. Accordingly if the steering mechanism of FIGS. 3A and 3B is utilized on a pontoon boat, a part of the side wall of the pod adjacent the actuator housing needs to be removed to provide a clearance in order to avoid collision, when the outboard motor is tilted, between the actuator housing and the adjacent side wall, e.g., side wall 60. Here, a part of the side wall 60 is removed to provide a clearance 61 for the actuator housing 48. As mentioned above, removal of a part of the side wall can degrade the strength of the pod.

(14) The steering system in accordance with the invention, as shown in FIGS. 4A and 4B, utilizes a hydraulic cylinder unit comprising a cylinder 62, a cylinder ram 66, an actuator housing 68, and valve mechanism 69, shown schematically and preferably located withing the actuator housing 68 and controlled by movement of a pivoted actuator arm 72, to effect extension and retraction of the cylinder ram relative to the cylinder. The cylinder 62 is offset from a central location between the side walls of the pod toward side wall 64 of the pod. By virtue of this offset relationship, even when the cylinder ram 66 and actuator housing 68 are fully extended, the actuator housing 68 does not reach a location above the opposite side wall 70.

(15) Because the cylinder unit is offset toward the starboard side, the pivoted actuator arm 72 is located on the top of the actuator housing 68 to avoid collision with the adjacent clamp bracket when the cylinder ram is retracted. The steering arm 74 is connected to the actuator housing 68 by a link 76 and a boss 77 that is fixed to, and extends upward from, the actuator housing 68 though an opening (not shown) in the actuator arm 72. The opening is larger than the boss 77, and provides a clearance that allows a limited degree of pivoting movement of the actuator arm 72 on the actuator housing.

(16) A cable ram 78 is slidable in a tilt tube 80 and is controlled by a remote steering helm (not shown) by a cable 82 that is movable in a cable sheath 84. The cable ram 78 is connected to the actuator arm 72 though an L-shaped secondary link 86 that has a first part 88 that extends upward from the end 90 of the cable ram and a second part 92 that extends parallel to the cable ram but in a direction opposite to the direction in which the cable ram extends from the tilt tube 80. The tilt tube 80 can be in its usual relationship to the swivel bracket 94, i.e., in a central location relative to the transom, and the cable ram 78, the actuator housing 68, and the cylinder ram 66, are movable through a range such that the outboard motor can be steered from a full right turn position to a full left turn position without having the actuator housing 68 reach a position such that it can collide with the side wall 70 of the pod if the engine is tilted. As is apparent from FIGS. 4A and 4B, even if the engine is tilted by 90, the secondary link will not collide with the side wall 70 of the pod. Thus it is unnecessary to remove a part of the side wall 70.

(17) In a modified version of the steering system, the cylinder ram can be fixed to the pod while the cylinder is movable and carries the actuator housing. This and various other modifications can be made to the apparatus described above without departing from the scope of the invention, which is defined by the following claims.