A movable boat propulsion apparatus comprising a drive assembly interconnected to an inboard drive means and propeller means by a first and second universal joint respectively.
2. Description of the Prior Art
A number of tiltable marine propulsion systems have been developed such that the propeller housing is freely tiltable should the propeller means impinge on an obstruction such as bottom or submerged objects to prevent destruction of the propeller. In addition, the propeller is generally tilted up for docking, shallow water trolling and the like. Such tiltable systems are almost universally restricted to use with outboard motors.
A problem which exists with tilting of inboard drive means is the excessive thrust or torque generated when the propeller is in a partially tilted position. This can exert a destructive force on the motor and drive assembly unless appropriate provision is made to safeguard against such emergency conditions. Unfortunately, most safeguard systems include various expensive warning and control systems to prevent an overload condition.
Most existing tilt or lift mechanisms include motorized drive-lift mechanisms with pulley and cable arrangements which are expensive to manufacture and operate. In addition, these tilt systems generally vary the horizontal thrust component when tilted thereby reducing the effective power of the entire propulsion system.
Thus, there is a need for an improved marine drive tilting mechanism particularly for inboard drives including tilting means with safety features inherent in the tilting which is relatively inexpensive to manufacture, dependable, and economical to operate.