FR2780699A1 - Regulated propellor for sailing vessel - Google Patents

Abstract

The propellor has a crank (6) mechanism, where the movement of the crank is limited by a screw (8) connected to the crank allowing the blades of the propellor to be secured in a position with total control over their position. A movable positional stop (9) which is shaped as a star, is used to position the blades of the propellor depending on the direction of rotation of the motor shaft. It moves the blades to different positions for navigation in forward or backward directions.

Description

-1- This invention relates to a propeller specially adapted to the

  sailing and whose performance both in

  forward and reverse is optimum.

  There are three types of propellers used for sailboats, and all are designed to try to meet demanding specifications: offer a minimum drag in sailing; - allow the skipper to perform engine maneuvers when certain situations require it (zero wind,

  emergency maneuvers, port maneuvers).

These three types of propellers are:

- Fixed propellers.

- The "duckbills".

  - Feathering propellers Fixed propellers have the advantage of simplicity and low cost, but the huge disadvantage of causing significant turbulence in sailing and therefore

to brake the sailboat.

  The "duckbills" They have a low drag in sailing, but do not have adjustment possibilities and have poor performance in reverse;

  moreover, their operation is quite brutal.

  Automatic feathering propellers offer a good compromise: low drag in sailing, good forward efficiency, fairly good in reverse and

possibility of adjustment.

  However, with regard to certain points, there are some shortcomings: - The fineness of adjustment is limited to 2 (1 in the best of cases), and the adjustments call on mechanisms whose use or implementation are very complicated. - The pitch angles of the blades are similar in -2- forward and reverse while in all logic, a sailboat moving with the engine does not have the same requirements as for its propulsion in forward

than in reverse.

  - The stop allowing the setting of the blades becoming metal against metal actually causes noisy operation. the present invention consists of a propeller, the blades of which adopt a different angular position depending on whether the sailboat is traveling under sail, with the engine in forward gear or with the engine in reverse gear, and this in a fully automatic manner. reversing in neutral, the blades, which can pivot with an amplitude of more than 180 on their axis of rotation, adopt, by the fact of the hydrodynamic pressure, the flag position thus offering the least resistance to advancement. When moving forward, the rotation of the propeller shaft causes the blades to rotate because they are feathered, they offer maximum resistance to water. Thanks to a crank rod system, the rod being located in the extension of the motor axis and passing through the rear half-part of the propeller hub, the crank being located on the blade hub, the rotational movement of the blades is transformed into a translational movement.The stroke of the connecting rod will be limited by a screw nut system, the nut abutting on a rotary stop located on the rear part of the propeller hub. We can adjust the length of the stroke with the desired precision thanks to the nut, which allows to obtain the fineness of adjustment claimed by the invention. (the length of the stroke corresponding to a determined degree of pitch) In reverse, the principle which determines the pitch of the blades is identical to that described for forward travel, but a screw system nut , coaxial with the connecting rod, differ -3- from that which determines the stop of the forward drive will be wedged on a mobile stop controlled by the rotation of the motor shaft. This feature therefore allows different angular positioning depending on the direction of rotation.

  of the engine being one of the claims of this

  invention. The rotary stop (whose rotation is integral with the blades) is graduated according to the principle of a vernier and the movable index will give precisely the setting angle of the

  blades, the rear part of the hub being graduated in degrees.

  The fact that the stopper is located on the axis of movement of a connecting rod whose movement is rectilinear-reciprocating makes it possible to interpose between the fixed part and the mobile part, a material absorbing the shocks in order to soften it

the operation.

  Still for a damped operating purpose, the stop adjustment nut, integral with the connecting rod, can act as a piston and move in a cylinder filled with oil.

  allowing smooth operation.

  The accompanying drawings illustrate an embodiment of the invention. Figure 1 shows a sectional view along the logitudinal axis. Figure 2 shows a rear view

  allowing the understanding of the mobile stop.

  The propeller breaks down into a hub (1) integral with the motor shaft (2). A central pinion (3) integrally connected to the hub (l), drives the blade pinions (4). These form 1 via the axis (5) and the part (6) a rod-crank assembly which transforms the rotational movement of the

blades in translational motion.

  The travel of the part (6) is limited by the nut (8) which comes to wedge on the stop (9) (perforated stop), the length of the stroke determining the pitch angle of the blades. ) being linked in rotation by means of the pinions (10) and (4) to the pinion (3), it follows that according to -4- the direction of rotation of the motor shaft, the pins (11) (in number of 3) will serve either as a stop, or they will be housed in the recesses of the stop (9) and in this case, the stop

  will be done through the nut (8).

  The assembly (11) (12) (13) being free in translation and integral in rotation relative to the part (6), it is

  held in position by the nut (14).

  The position (considered on the longitudinal axis) of the nut (8) can be different depending on the settings of the position of the pins (11), a different setting is obtained from

  blades according to the direction of rotation of the motor.

  A simplified model would obtain the same results: the central pinion being eliminated, the rotation of the blades would be ensured by the play of hydrodynamic pressures. The part (13) being provided with a seal and oil passages calibrated, by moving in a cylinder (16) filled with oil one obtains a

damped operation.

  In addition, for cost reasons, it is possible to produce a simplified propeller, the timing of which would be determined as soon as it is made, therefore without the possibility of adjustments by eliminating the pinion (10), the rotary stop (9).

and the assembly (11), (12), (13).

  The rotary stop (9) being provided with a reference, the rear half bearing (7) being graduated in degrees, we will know precisely the angular setting of the blades and this in direct reading. -5--

Claims (4)

  1) Propeller for sailboat with automatic feathering with "fine" pitch setting and differentiated for forward and reverse, characterized by a connecting rod-crank device whose stroke is limited by a nut (8) integral with the connecting rod (6) allowing the blades to be propped up in a determined position with total finesse of adjustment. 2) Propeller characterized according to claim 2 by a movable stop (9), in the shape of a star which allows, according to the direction of rotation of the motor shaft, to obtain a different pitch angle depending on whether one is sailing in motion before or in reverse.   3) Propeller characterized according to claim 2 by a special screw-nut system (11,12,13) making it possible to obtain an angular setting of the different blades depending on whether the pins (11) abut on the stop (9) or that they are housed in the recesses of (9) in which case the stop will be obtained by the nut (8).   4) Propeller characterized according to claim 3 by the part (13) provided with a seal, the latter sliding in a cylinder (16) filled with oil provides a damped operation. ) Propeller characterized according to claim 4 by a dial graduated in degrees on the rear half bearing (7) the movable reference being located on the stop (9), this allowing a direct reading setting.