The present invention relates to a control system for a two or more speed motorised winch. The invention also relates to a method for controlling a winch of the type described above.

The invention has a preferred, although not exclusive, application on nautical winches in sailing boats for cruising and/or competition, or in any case in medium-large sized boats, where motorised winches with many speeds are used to manoeuvre the sails of the boat.

With particular reference to nautical winches, as known, such winches are used in sailing boats to facilitate the operations under tension for manoeuvring and adjusting the sails, like for example the positioning and hoisting thereof. Such operations are carried out by manoeuvring suitable lines or ropes (commonly indicated with the term: sheets or halyards) suitably connected to the sails.

Winches essentially comprise a support body intended to be fixed onto the deck of the boat and a drum rotatably associated with the support body and intended to receive the windings of the line for manoeuvring the sail. The drum is fitted coaxially onto the support body along a main shaft of the latter and is free to rotate with respect to the support body in a first direction of rotation (for example, in the clockwise direction), so as to wind the line on the drum, the drum being instead locked in the opposite direction of rotation. In this way, the drum transfers a traction force to the line during the operations under tension for recovering the line itself.

Above all in medium-large sailing boats, motorised winches are used. In such winches, the actuation force of the winch is supplied to the aforementioned main shaft by suitable motor means, typically electric or hydraulic, associated with the winch itself. Such motor means are normally housed below deck and can be activated through hand or pedal switches located above deck.

For a more effective action on the sails during the different manoeuvres, for some time winches with two speeds (or with two gear ratios, the two terms being used interchangeably) have been known and widely used. Such winches make it possible to vary the ratio between the rotation speed imparted by the motor means to the main shaft of the winch and the rotation speed of the drum. In this way, it is possible to use a long gear ratio (or first speed, corresponding to a high rotation speed of the drum and to a low pulling action) for a quick recovery of the line in the presence of limited traction loads on the line and a short gear ratio (or second speed, corresponding to a low speed of the drum and to a high pulling action) in the presence of higher traction loads.

Two-speed winches normally provides for a first gear ratio being operative when the actuation of the main shaft of the winch occurs in a first direction of rotation, and the second gear ratio being operative when the actuation of the aforementioned main shaft occurs in the opposite direction. The change in gear ratio is thus obtained by simply changing the direction of rotation of the main shaft of the winch (it should be noted that the direction of rotation of the drum on which the line is wound still remains the same, any rotation in the opposite direction indeed being prevented). For this purpose, two buttons, pedals or levers are typically provided on deck so that, when pressed, they activate a respective speed. Winches of this type are satisfactory in many applications.

In reality, not all manoeuvres require the same type of force. Indeed, typically, in down-wind sailing lesser forces and larger movements of the sails are required compared to close-hauled sailing. In such a case it is advantageous to provides for a longer gear ratio (i.e. a greater rotation speed of the drum) to allow a higher recovery speed of the line.

For this purpose, three-speed winches have been developed. The change from one gear ratio to the other basically always occurs through a change in direction of rotation of the main shaft of the winch. Typically, the first speed is selected by inserting a speed variator (typically a speed reducer) (generally by pressing a button provided on the winch and one of the buttons provided on the deck of the boat) so that a long gear ratio (high recovery speed, low pulling action) is initially available. The passage to an intermediate gear ratio (second speed, first inversion of the direction of rotation of the main shaft of the winch, lower rotation speed of the drum, greater pulling action) is obtained by pressing the other button provided on the deck of the boat; pressing this button also causes the speed variator to automatically be released. The passage to a short gear ratio (third speed, second inversion of the direction of rotation of the main shaft of the winch, low rotation speed of the drum, high pulling action) is obtained by pressing the first button provided on the deck of the boat, the speed variator being still released.

For obvious safety reasons, the sizing or calibration (in terms of torque which can be delivered to the winch by the motor means and corresponding capability of the winch to bear traction loads on the line) of motorised multi-speed winches is carried out so as to deliver as maximum torque that force which is required to the winch to pull its maximum working load when the lowest speed is selected. This is the case that corresponds to the situation in which the line wound on the winch is subject to the maximum traction loads.

The Applicant has however noted that such a sizing or calibration penalises the performance of the winch at the higher speeds. Indeed, the aforementioned sizing, at such higher speeds, sets a maximum torque limit deliverable by the motor means that is low (very low in the first speed). Such a maximum limit is certainly lower than that which the respective gear ratios would allow to be obtained.

Four-speed winches are known, i.e. in which a fourth gear ratio is provided, located between the long ratio and the above called intermediate ratio; see for example US 4,667,934. However, they are very mechanically complex (and therefore heavy and expensive) devices and their use is rather laborious.

The Applicant has therefore felt the need to improve the performance of motorised winches with two or more speeds at the longer gear ratios, still keeping the necessary safety conditions that require that the winch be sized based upon the lowest speed, corresponding to the situation in which the line wound on the winch is subject to the maximum traction loads.

The invention therefore relates, in a first aspect thereof, to a control system for a motorised winch having two or more speeds, the motorised winch comprising a main motion input shaft, a drum for winding a line and a plurality of gears operatively arranged between the main shaft and the drum and adapted to define in the winch at least two different gear ratios, motor means being active on said main shaft for transmitting the motion to the winch, the control system being characterised in that it comprises detector means adapted to identify the gear ratio active in the winch and control means active on the motor means to adjust the torque and/or speed delivered by the motor means based upon the detected gear ratio.

Advantageously, the control system devised by the Applicant allows, through detection of the gear ratio active on the winch, the torque and/or speed delivered by the motor means to be automatically increased when a long gear ratio is active in the winch (thus at the first speed, in the case of two-speed winches and at the first and second speed, in the case of three-speed winches) and allows no adjustment to be made to the motor means when a short gear ratio is active in the winch (for example, in two-speed winches, when the second speed is selected, and in three-speed winches, when the third speed is selected). In this way the performance of the winch at the longer gear ratios is improved, ensuring that it is possible to deliver to the winch a greater torque and/or speed than that which can be delivered to known winches with the same gear ratio, and thus allowing the winch, at such gear ratios, to bear a traction load on the line which is greater than that which can be borne, the gear ratio being equal, by known winches. All of this while still sizing the winch based upon the lowest speed, so as to remain in safe conditions.

The motor means can be electric or hydraulic.

Preferably, irrespective of the specific embodiment of the motor means, in the case in which the winch is of the two-speed type, the aforementioned plurality of gears is adapted to define in the winch a first gear ratio at which the drum of the winch rotates at a first speed and a second gear ratio at which the drum rotates at a second speed lower than the first speed. In this case, the control means act on the motor means to increase the torque and/or speed delivered by the motor means when the first gear ratio is active in the winch.

On the other hand, in the case in which the winch is of the three-speed type, the aforementioned plurality of gears is adapted to define in the winch a first gear ratio at which the drum rotates at a first speed, a second gear ratio at which the drum rotates at a second speed lower than the first speed, and a third gear ratio at which the drum rotates at a third speed lower than the second speed. In this case, the control means act on the motor means to increase the torque and/or speed delivered by the motor means when the first or second gear ratio is active in the winch.

Preferably, the control system of the present invention comprises actuation means which can be controlled to selectively activate a predetermined gear ratio in the winch. Said actuation means preferably comprise at least one pair of pedal, button or lever elements (hereafter, for the sake of simplicity, indicated as: buttons) adapted to be activated to select a respective predetermined gear ratio. In the case of three-speed winches, the aforementioned actuation means also comprise a button mounted on the winch and intended to be activated to select a further predetermined gear ratio (typically through a speed variator).

The detection of the gear ratio active on the winch can occur in various ways and through different types of detector means.

In the case of a two-speed winch, the aforementioned detection can for example consist simply on detecting which of the two buttons is pressed, or the direction of rotation of the main shaft.

Alternatively, and in the case of three-speed winches, the aforementioned detection occurs by providing at least one speed sensor associated with the drum of the winch and at least one detection element associated with the motor means and adapted to detect a parameter which identifies the operating condition of the motor means. Such a detection element preferably comprises a speed sensor associated with the motion output shaft of the motor means (such a shaft hereafter being called: drive shaft). Alternatively, in the specific case of hydraulic winches, the aforementioned detection element can comprise a measuring device of the flow of fluid dispensed by the hydraulic motor (the flow and the pressure are indeed correlated to the speed of the drive shaft by a substantially linear relation).

Advantageously, it is possible in this case to detect the rotation speed of the drum and the rotation speed of the drive shaft, and therefore the gear ratio active in the winch (such a ratio being given by the ratio of the aforementioned speeds).

In a further alternative embodiment of the control system of the present invention, the detection of the gear ratio active on the winch is carried out by providing at least one movement sensor associated with at least one gear of the plurality of gears, such a gear being in a condition of mechanical engagement when a first gear ratio is active in the winch and in a condition of mechanical disengagement when a different gear ratio is active in the winch.

Advantageously, this case exploits the fact that, in the passage from one gear ratio to another, some of the gears that are in an engaged condition when a first gear ratio is active in the winch are released when a different gear ratio is active in the winch. The detection of the movement or otherwise of such gears thus allows the gear ratio active on the winch to be identified.

In a further alternative embodiment, in the specific case of three-speed winches, the detection of the gear ratio active on the winch occurs by also providing at least one proximity sensor associated with the button provided on the winch. Such a sensor provides for the information on the possible actuation or deactivation of the speed variator; such information, combined with that indicating which of the aforementioned two buttons is pressed, makes it possible to discover the gear ratio active on the winch.

Preferably, in the case in which sensors are used, at least some of such sensors are of the wireless type, so as to avoid the presence of wires, which, particularly when associated to the rotary components of the winch, would be undesirable.

In a second aspect thereof, the present invention relates to a method for controlling a motorised winch haying two or more speeds, the motorised winch comprising a main motion input shaft, a drum for winding the line and a plurality of gears operatively arranged between the main shaft and the drum and adapted to define in the winch at least two different gear ratios, motor means being active on said main shaft for transmitting the motion to the winch, such a method comprising the steps of:

• detecting the gear ratio active in the winch;
• adjusting the torque and/or speed delivered by the motor means based upon the detected gear ratio.

Advantageously, such a method can be actuated by a control system of the type described above and thus allows all of the advantages described above with reference to the aforementioned control system to be achieved.

Further characteristics and advantages of the present invention shall become clearer from the following detailed description of some preferred embodiments thereof, made with reference to the attached drawings. In such drawings:

• figure 1 is a schematic view of a first embodiment of a control system according to the present invention;
• figure 2 is a schematic view of a second embodiment of a control system according to the present invention;
• figure 3 is a schematic view of a third embodiment of a control system according to the present invention;
• figure 4 is a schematic view of a fourth embodiment of a control system according to the present invention;
• figure 5 displays a table and a graph relative to the operating parameters of a conventional three-speed hydraulic winch.

In figures 1-4, a preferred embodiment of a control system for a motorised winch according to the present invention is indicated with 1. The winch, which is in particular a nautical winch, is indicated with 2 and the motor means are indicated with 3. The winch is illustrated as being associated with a deck of a sailing boat, schematically indicated with 4, with the motor means 3 positioned below deck.

The control system 1 has a preferred application in sailing boats for cruising and/or competition, or in any case in medium-large boats.

The winch 2 comprises an inner stator body or support (not illustrated and per sé conventional), intended to be fixed on the deck 4 of the sailing boat, and a rotor body 20 or drum, also conventional, rotatably associated with the support and intended to receive the windings of a line 100 for manoeuvring a sail of the sailing boat.

The drum 20 is fitted coaxially onto the support, along a main shaft 10 adapted to control the rotation (the longitudinal axis of which is indicated with X-X), through the interposition of a plurality of rolling bearings (not illustrated) adapted to allow the relative rotation of the drum 20 with respect to the support. Such a rotation is imparted to the main shaft 10 of the winch 2 by the motor means 3 through a drive shaft 3a.

The rotation is then transferred to the drum 20, in a per sé known way, through a plurality of conventional gears (illustrated with a dashed line, in reduced number and absolutely schematically, only in figure 4). The rotary body 20 is free to rotate with respect to the stator body in a single direction of rotation (for example in a clockwise direction of rotation), which corresponds to the winding direction of the line 100 onto the drum 20.

In this way, the drum 20 transfers to the line 100 a traction force which is suitable for overcoming the load T present on the line during the operations under tension for recovering the line itself.

The motor means 3 can be electric or hydraulic. Therefore, suitable electronic or hydraulic boxes (indicated with 5 in the attached figures) are provided to feed the motor means 3.

The actuation of the motor means 3 is carried out by actuating a switch 30 arranged above deck.

In the specific embodiments illustrated in figures 1-4, the winch is a three-speed winch. Therefore a pair of buttons 6a, 6b are provided above deck adapted to control the passage from one gear ratio to another gear ratio. A button 7 is also provided on the winch 2 and it is intended to be pressed to select a further gear ratio (through a speed variator). The changing from one gear ratio to the other always occurs through changing of the direction of rotation of the main shaft 10 of the winch 2.

In the winch 2 it is thus possible to define a first gear ratio at which the drum 20 rotates at a first speed, a second gear ratio at which the drum 20 rotates at a second speed lower than the first speed, and a third gear ratio at which the drum 20 rotates at a third speed lower than the second speed.

In the specific case illustrated in figures 1-4, the first speed is selected by pressing the button 7, so as to insert the speed variator, and the button 6a, so as to make the main shaft 10 rotate in a first direction of rotation; in this way a long gear ratio (high recovery speed of the line, low pulling action) becomes available. The passage to the intermediate gear ratio (second speed, first inversion of the direction of rotation of the main shaft of the winch, slower recovery speed, greater pulling action) is obtained by pressing the button 6b; pressing this button causes the speed variator to be automatically released (the button 7 then goes back into its initial position). The passage to the short gear ratio (third speed, second inversion of the direction of rotation of the main shaft of the winch, low recovery speed, high pulling action) is obtained by pressing the button 6a, with the multiplier remaining released.

In accordance with the present invention, the control system 1 comprises detector means adapted to identify the gear ratio active in the winch 2 and control means adapted to control the motor means 3 so as to adjust the torque and/or speed delivered by them to the winch 2 based upon the detected gear ratio. In particular, the control means are adapted to automatically increase the torque and/or speed delivered by the motor means 3 when a long gear ratio (thus at the first and second speed) is active in the winch 2 and not to carry out any adjustment of the motor means when a short gear ratio (i.e. when the third speed is selected) is active in the winch.

In the embodiment illustrated in figure 1, the detector means comprise a speed sensor 40 (preferably of the wireless type) associated with the drum 20 of the winch 2 and a speed sensor 41 (also preferably of the wireless type) associated with the drive shaft 3a of the motor means 3.

In the case of hydraulic winches, as an alternative to the sensor 41 it is possible to use a measuring device 42 of the flow of fluid dispensed by the hydraulic motor (figure 2).

In a further alternative embodiment of the control system 1 of the present invention, illustrated in figure 3, the detection of the gear ratio active on the winch 2 is carried out by providing at least one proximity sensor 43 (preferably of the wireless type) associated with the button 7, so as to have the information on the possible activation or release of the first speed, and detecting which of the two buttons 6a, 6b is pressed, so as to have the information on the direction of rotation of the main shaft 10. The combination of the aforementioned information makes it possible to discover the gear ratio active on the winch 2.

In yet another further alternative embodiment of the control system 1 of the present invention, illustrated in figure 4, the detection of the gear ratio active on the winch 2 is carried out by providing at least one movement sensor 44 associated with at least one gear of the winch 2 that disengages, when passing from one gear ratio to another, thus stopping rotating.

The control system 1 also comprises control means 50 of the motor means 3. Such means consist in particular of a microprocessor 50 associated with the box 5 which feeds the motor means 3.

The microprocessor 50 receives the signals generated by the sensors 40 and 41 (in the embodiment of figure 1), or by the sensors 40 and by the flow or pressure measuring device 42 (in the embodiment of figure 2), or by the sensor 43 and by the buttons 6a and 6b (in the embodiment of figure 3), or by the sensor 44 (in the embodiment of figure 4). Once the aforementioned signals have been received, the microprocessor 50 is able to work out the gear ratio active on the winch 2 and, based upon this information, to adjust the motor means 3 (through the respective box 5) so as to increase the torque and/or speed delivered by the motor means 3 (and therefore the load that can be borne by the winch) when the first or second gear ratio is active in the winch 2. This allows the performance of the winch 2 at the aforementioned gear ratios to be improved.

Through the system described above it is thus possible to actuate a method to control a motorised winch 2 having two or more speeds. Such a method comprises the steps of detecting the gear ratio active in the winch 2 and adjusting the torque and/or speed delivered to the winch by the motor means 3 based upon the detected gear ratio, so as to increase the load that can be borne by the winch when a long gear ratio is active in the winch.

The activation of the different gear ratios by a member of the crew and the automatic detection of the gear ratios active in the winch can be made according to the ways described above.

An example of the improvement that can be achieved through the control system 1 of the present invention is illustrated in figure 5. In such a figure the operating parameters of a conventional three-speed hydraulic winch are shown.

The table in the top left hand side shows, in the first column, the pressure values for feeding the winch and the torque values delivered to the winch. The table at the side, on the other hand, shows, in the last three columns, the values of the load that can be borne by the winch at three different gear ratios. The graph shows the progression of the load according to the pressure at the aforementioned three different gear ratios.

Figure 5 illustrates how, for example, at a pressure value of 135 bars, the values of the load that can be borne by the winch are 2056 N at the first speed, 20967 N at the second speed and 90773 N at the third speed.

It is clear how, at the first two speeds, the load that can be borne by the winch is quite low.

The present invention allows the values of the load that can be borne by the winch at the aforementioned first two speeds to be increased, being able for example to obtain a value of 2944 N at the first speed and a value of 30033 N at the second speed.

It is thus clear how the main improvement that can be obtained with the present invention is correlated to the possibility of adjusting the torque and/or speed that can be delivered by the motor means in the different speeds of the winch. At the same time, the same sensors and microprocessor could adjust the torque and/or speed of the motor means differentiating it, speed by speed, between preset values.

The possibility of adjusting the speed and/or torque for each speed of the winch thus optimises the delivery of the torque and/or speed of the motor means to the winch.

The man skilled in the art will have no difficulty in understanding that what has been described above is applicable in a totally equivalent way to a two-speed winch or to one with more than three speeds. In the case of a two-speed winch, the detection of the gear ratio active in the winch can consist simply of detecting which of the two buttons 6a, 6b provided on the deck of the boat is pressed. In this case, the control means 50 act on the motor means 3 to increase the torque and/or speed delivered by the motor means 3 when the first gear ratio is active in the winch.

Of course, a man skilled in the art can make numerous modifications and variants to the control system described above in order to satisfy specific and contingent requirements, all of which are covered by the scope of protection of the present invention as defined by the following claims.