MECHANISM FOR ENHANCING THE MAN UVRABILITY OF SMALL BOATS

Abstract: Mechanism for increasing the turning radius of small size boats (11), provided with an outboard motor (2), wherein the steering is effected by means of the rotation of said motor (2) and characterized in that it comprises an auxiliary rudder (7) arranged in prolongation of the propeller of said motor.

Description: PURPOSE OF THE INVENTION The present invention refers to a system that is designed to increase the manoeuvrability of small size boats which are fitted with an outboard motor, where the manoeuvre is performed by turning this motor. ANTECEDENTS OF THE INVENTION Boats nowadays with an outboard motor, where the manoeuvre is made by turning that motor, have manoeuvrability problems when the propeller turns at low revolutions, such as when, for example mooring manoeuvres or cruising inside marinas or ports where there is usually a restricted speed. The origin of these problems is because in motors of this kind, it is the propeller which acts as rudder, and it has a lower performance when its speed of rotation is reduced. An additional problem which is presented in this kind of motor is the restricted lock which can be reached with these motors which, for construction reasons, is usually limited to 30 or 35º. The problem of increasing manoeuvrability at low speed has in the case of big boats been resolved by adding propellers which are fitted with a cross axle to the keel line, at bow and stern, within a tunnel performed in the hull. Evidently, the construction of this kind of mechanisms is mechanically complicated because additional motors are needed which render their cost prohibitive to be used in small boats. The purpose of this invention is to achieve an increase in the manoeuvrability of this sort of boat without having to fit additional drive systems, and it can be applied in all kinds of boats which have a motor whose propeller works as rudder. DESCRIPTION OF THE INVENTION The increase in manoeuvrability of boats of this kind is obtained by reducing their locking radius, and this can be achieved with the help of an auxiliary rudder fitted after the motor propeller, whose locking axle is solidary to this and whose operation does not require any additional energy supply. Such an arrangement has been disclosed in AU-B-527 066. the auxiliary rudder of the present invention is capable of reducing the locking radius, and even achieves its rotation on itself, without having to add additional controls or drives to the regular ones in this sort of boat. A mechanism to increase the locking radius in accordance with the present invention offers the following advantages: First of all, there is no change in the form of manoeuvring the boat, because its form of action consists of increasing the effect of its normal locking mechanism. A minimum resistance f'ward is introduced when travelling at high speed, because the boat's aerodynamic profile is optionally designed so that the rudder reaches high velocities which will reduce this resistance even further. No energy source whatsoever is needed for manoeuvring because the locking angle depends on the position of the motor at each moment. It is easy to fit and to maintain thanks to the small number of parts which it comprises and the simple handling of its mechanism; for this same reason it has a very low cost. To provide a better understanding of this descriptive report and forming an integral part of same, some figures are enclosed below which represent the purpose of the invention in an illustrative but not a limitative way. BRIEF DESCRIPTION OF THE FIGURES Figure 1 - Represents a side view of the locking mechanism fitted on an outboard motor. Figure 2 - Represents a top view of the mechanism represented in the above figure. Figure 3 - Represents a top view of the mechanism represented in figure 1 in its position turning starboard. DESCRIPTION OF AN EXAMPLE OF EXECUTION OF THE INVENTION A description of an example of execution of the invention is given below, referring to the numeration that has been adopted in the figures. The mechanism to increase the manoeuvrability in this form of execution consequently consists of one pulley 4, arranged on the cavitation plate of propeller 1 of motor 2, through which we pass a cable, belt or chain 9, which is fixed to the stern of the boat, on each side of the motor 2. By turning motor 2, pulley 4 is forced to rotate via the lineal component 9. Geometrically the movement of pulley 4 in respect of enclaves 10 of the lineal component 9, would describe an ellipse arch whose focuses would be enclave points 10. However, and because this pulley 4 is solidary to motor 2, and because this describes a circumference around its own locking axle 3, a pivotal movement of the pulley 4 would be actually limited by the length of the portion of the lineal element 9 at the side of the motor 2 opposite to the turning direction of the motor, so that there must be a flexible union means between the lineal component 9 and the boat in order to compensate the differences in length between both runs, and to allow thereby movement of the pulley starboard or port. In accordance with figure 3 where the starboard turn of motor 2 has been represented, viewed from an elevated position, the form of operation of this mechanism is described below. This starboard turn of motor 2 implies a turn in a clockwise direction of pulley 4. The presence of a gear 6 interlocked with gear 5, which in turn is solidary to pulley 4, allows the turning direction to be reversed, and consequently this second gear 6 will turn in an anti-clockwise direction, or in other words, will turn in the same direction as motor 2. Axle 8 of this second gear 6 corresponds to the axle of the auxiliary rudder 7 which is arranged after propeller 1. These gears, apart from allowing a suitable turning direction of the rudder 7 to be obtained, allow its locking angle to be increased in respect of the locking angle of motor 2, in terms of the relative dimensions of gears 5 and 6, so that angles of more than 90° can be obtained between the auxiliary rudder 7 and the motor 2. It is observed that this mechanism allows the flow of water to be progressively modified, and not only does this facilitate port manoeuvers, but also navigation at low speed. In addition, devices are foreseen which impede the action of the auxiliary rudder at moderate or high speed in order to avoid the effects of an abrupt swing which could be produced at high speed.

Claims: Mechanism to increase the manoeuvrability of a boat which has an outboard motor or semi-outboard which comprises an auxiliary rudder (7) which is arranged after the propeller (1) of that motor (2) and means to transmit the turning movement to that rudder (7) simultaneously with the turning movement of that motor (2) in such a manner that the locking angle of the auxiliary rudder (7) progresively increases with regard to the locking angle of the motor (2), characterized in that it includes: a pulley (4) arranged at the rear of this motor (2) which is capable of transmitting a turning movement to a first gear (5), a second gear (6) which interlocks with the first gear (5) and arranged on the locking shaft (8) of that rudder (7); a lineal component (9) attached at each end to the boat on either side of the turning axle (3) of that boat (2) and which passes by that pulley (4) to provide rotational movement to said pulley (4). Mechanism in accordance with claim 1, characterized in that the union of the ends of this lineal component (9) to the boat are elastic means (10) which allow the tension of the lineal component (9) to be maintained. Mechanism in accordance with claim 1, characterized in that the union of that component to the boat consists of a system of pulleys and counter-weights to maintain the tension of that lineal component (9). Mechanism in accordance with claim 1, characterized in that this lineal component 89) is a cable. Mechanism in accordance with claim 1, characterized in that this element of union (9) is a belt. Mechanism in accordance with claim 1, characterized in that this lineal component (9) is a chain. Mechanism in accordance with claim 1, characterized in that it includes means to disconnect that rudder (7) to prevent the manoeuvrability of the boat from being affected at a given speed. Mechanism in accordance with claim 7, characterized in that these means to disconnect allow these gears (5,6) to operate only from a pre-determined speed of the boat. Mechanism in accordance with claim 7, characterized in that these means for disconnecting make it possible for this lineal component (9) to compel the turning of that pulley (4) only from a given locking angle of that motor (2). Mechanism in accordance with claim 7, characterized in that these means of disconnecting provoke the ungearing between gears (5) and (6) from a pre-established speed of the boat by effect of greater water pressure. Mechanism in accordance with claim 7, characterized in that those means for disconnecting allow the ungearing between gears (5) and (6). Mechanism in accordance with any of the precedent claims, characterized in that it includes a protector cover of pulleys and gears.

Inventors: GARCIA NORENA ALFONSO, GARCIA NORENA, ALFONSO
Applicants: GARCIA NORENA ALFONSO, GARCIA NORENA, ALFONSO
Application year: 1993
Main classification: B63H20
IPC codes: B63H20, F02B61, B63H25