WO2013172767A1

WO2013172767A1 - Propeller arrangement and sailing boat comprising such a propeller arrangement

Info

Publication number: WO2013172767A1
Application number: PCT/SE2013/050511
Authority: WO
Inventors: Hans HEDSTRÖM
Original assignee: Digatech Ab
Priority date: 2012-05-14
Filing date: 2013-05-07
Publication date: 2013-11-21
Also published as: SE536080C2; SE1250490A1

Abstract

The invention relates to a propeller arrangement (1) for a sailing boat comprising: - a lateral-propeller unit (10), which comprises a motor and a propeller driven by the motor; and a holder element (30) which carries the lateral-propeller unit (10), this holder element (30) consisting of a stern ladder which is intended to be attached to the transom of a sailing boat and which comprises two elongated and mutually parallel side pieces (33, 34), which are arranged at a distance from each other, and several mutually parallel rungs (35) distributed in the longitudinal direction of the stern ladder, which rungs extend between the two side pieces (33, 34) and are attached to these side pieces. The invention also relates to a sailing boat comprising such a propeller arrangement (1).

Description

Propeller arrangement and sailing boat comprising such a propeller arrangement

FIELD OF THE INVENTION AND PRIOR ART

The invention relates to a propeller arrangement according to the preamble of claim 1 . The invention also relates to a sailing boat comprising such a propeller arrangement. When propelled by motor, most sailing boats are driven by an inboard motor, which, in contrast to an outboard motor, can not be used for steering the boat. The steering of the boat is instead done by means of the rudder of the boat, which requires speed in order to have effect. At low speed, the rudder has almost no ef- feet. When the boat is manoeuvred in narrow spaces, one therefore tries to produce speed by driving the boat forwards, going astern, driving forwards again and so on, which is complicated and time-consuming. To be able to produce a lateral force in a simple manner in order to steer the boat at low speed is a desire, which among other things would facilitate the manoeuvring of the boat in narrow spaces.

To solve this, a number of technical solutions have been developed. A stream of water that gives a lateral force can be produced by mounting a tube across the hull of the boat from the port side to the starboard side below the waterline and arranging a motor- driven propeller in this tube. Another technique is to lower a motor-driven propeller through a hatch in the bottom of the hull. According to another variant, a pump with associated hoses and jet nozzles are mounted in the hull. However, the above-mentioned techniques are expensive and require large measures to be taken with the hull.

In order to achieve more simple and less costly solutions, propel- ler arrangements have been developed where a lateral-propeller unit is mounted on the outside of the hull by means of a suspension device and in different manners is lowered into the water when it is to be used . The patent documents DE 1 0200701 9965 A1 , US 3251 330 A, US 4208978 A, US 47321 04 A, DE 3440554 A1 and EP 1 21 51 1 5 A2 show examples of such solutions.

In this description and the subsequent claims, the expression lateral-propeller unit refers to a propeller unit configured to be mounted on the outside of a boat in order be used, when need arises, for generating a lateral force that can be utilized for steering the boat.

OBJ ECT OF THE I NVENTION

The object of the present invention is to achieve a propeller arrangement of the above-mentioned type with a new and favourable design . SU MMARY OF TH E I NVENTION

According to the present invention , said object is achieved by means of a propeller arrangement having the features defined in claim 1 .

The propeller arrangement according to the invention comprises: a lateral-propeller unit, which comprises a motor, preferably in the form of an electric or hydraulic motor, and a propeller driven by the motor; and

- a holder element which carries the lateral-propeller unit, this holder element consisting of a stern ladder which is intended to be attached to the transom of a sailing boat and which comprises two elongated and mutually parallel side pieces, which are arranged at a distance from each other, and sev- eral mutually parallel rungs distributed in the longitudinal direction of the stern ladder, which rungs extend between the two side pieces and are attached to these side pieces. By using the stern ladder of the sailing boat as a holder element for the lateral-propeller unit, the lateral-propeller unit can be mounted at the stern of the sailing boat in a simple manner. The stern ladder can be used as a conventional stern ladder in connection with activities in the form of for instance bathing, berthing, boarding from a skiff and rescue activities, at the same time as the stern ladder functions as suspension for the lateral-propeller unit. The majority of sailing boats are provided with a stern ladder which is attached to the transom of the sailing boat. By using the stern ladder of the boat as suspension for the lateral-propeller unit, a cost-effective and space-effective solution is obtained, since no separate suspension device for the lateral-propeller unit needs to be acquired and mounted to the boat. When the lateral- propeller unit is mounted to the stern ladder of the boat, the lateral-propeller unit will not occupy any space on deck. Further- more, the lateral-propeller unit will be placed on the transom of the boat with this solution, i.e. at a maximum distance from the centre of rotation of the boat. By being located at a large distance from the centre of rotation of the boat, the lateral-propeller unit may give the boat a good steerage also at comparatively low mo- tor output.

Other advantageous features of the propeller arrangement according to the invention will appear from the dependent claims and the description following below.

The invention also relates to a sailing boat having the features defined in claim 13. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will in the following be more closely described by means of embodiment examples, with reference to the appended drawings. It is shown in:

Fig. 1 a schematic view from behind of the stern of a sailing boat provided with a propeller arrangement according to the present invention, with the stern ladder shown in a raised position,

Fig. 2 a schematic lateral view of the stern of the sailing boat of Fig. 1 , with the stern ladder shown in a raised position, Fig. 3 a schematic view from behind of the stern of the sailing boat of Fig. 1 , with the stern ladder shown in a lowered position,

Fig. 4 a schematic lateral view of the stern of the sailing boat of Fig. 1 , with the stern ladder shown in a lowered position,

Fig. 5 a schematic, partly cut lateral view of a lateral-propeller unit included in a propeller arrangement according to an embodiment of the invention,

Fig. 6 a schematic front view of the lateral-propeller unit of Fig.

5, Fig. 7 a schematic planar view from below of the lateral-propeller unit of Fig. 5,

Fig. 8 a schematic front view of parts included in the lateral propeller unit of Fig. 5, Fig. 9 a schematic front view of parts included in a lateral-propeller unit according to an alternative embodiment, and

Fig. 10 a schematic planar view from below of the lateral-propel- ler unit of Fig. 9.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A propeller arrangement 1 according to the present invention is shown very schematically in Figs. 1 -4. The propeller arrangement

1 is intended to be connected to the stern of a sailing boat 3 in order to facilitate the manoeuvring of the sailing boat at low speeds. The propeller arrangement 1 comprises a lateral-propeller unit 10 with a waterproof motor 1 1 , preferably in the form of an electric or hydraulic motor, and a propeller 12 driven by the motor. The propeller arrangement 1 further comprises a holder element in the form of a stern ladder 30. This stern ladder 30 is attached to the transom 2 of the sailing boat and carries the lateral-propeller unit 10. Consequently, the lateral-propeller unit 10 is connected to the transom 2 of the boat through the stern ladder 30.

A transom 2 of a sailing boat is a plane or slightly arched surface which constitutes the termination of the boat above the waterline.

In the embodiment illustrated in Figs. 1-4, the stern ladder 30 is pivotally connected to an attachment 4 which is intended to be mounted to the transom 2 of a sailing boat. The stern ladder 30 is at one end 31 articulately attached to said attachment 4, and the lateral-propeller unit 10 is mounted at the opposite second end 32 of the stern ladder. The stern ladder 30 is pivotable in relation to the attachment 4, and thereby in relation to the transom

2 of the sailing boat, about an essentially horizontal pivot axis to and fro between a lowered position (see Figs. 3 and 4), in which the second end 32 of the stern ladder and the lateral-propeller unit 10 are immersed below the water surface 6 behind the sailing boat 3, and a raised position (see Figs . 1 and 2), in which the stern ladder 30 and the lateral-propeller unit 1 0 are located above the water surface 6. The stern ladder 30 is configured to facilitate boarding from the water and is intended to reach down below the water surface 6 in the lowered position.

In the illustrated example, the lateral-propeller unit 1 0 is mounted on the side of the stern ladder 30 that faces inwards towards the hull of the sailing boat in the lowered position. Hereby, the lateral- propeller unit 1 0 will be located in a protected manner between the stern ladder 30 and the hull of the sailing boat in the lowered position . In the raised position , the lateral-propeller unit 1 0 will be located on the side of the stern ladder 30 that faces outwards away from the boat deck, and the lateral-propeller unit 1 0 will thereby not encroach upon the space of movement available to the persons who are on the boat deck. As an alternative, the lateral-propeller unit 1 0 could of course also be mounted on the opposite side of the stern ladder 30, i .e. on the side of the stern ladder 30 that faces away from the hull of the sailing boat in the lowered position . In the last-mentioned case, the lateral-propeller unit 1 0 may be used as a tread in the lowered position .

In a conventional manner, the stern ladder 30 comprises two elongated and mutually parallel side pieces 33, 34, which are ar- ranged at a distance from each other, and several mutually parallel rungs 35 distributed in the longitudi nal direction of the stern ladder, which rungs extend between the two side pieces 33, 34 and are attached to these side pieces. The motor 1 1 and propeller 1 2 of the lateral-propeller unit are with advantage arranged in a tubular casing 1 3, which suitably has a circular cross-sectional shape, as illustrated in Figs. 5 and 6. The lateral-propeller unit 1 0 is attached to the stern ladder 30 with the longitudinal axis of the tubular casing 1 3 extending essentially in parallel with the rungs 35 of the stern ladder. The motor 1 1 is fixed inside the casing 1 3 by means of brackets 14 or the similar. The casing 1 3 is provided with openings 1 5 at its ends. These openings 1 5 are with advantage covered by a grating or net. The casing 1 3 guides the water flow emitted from the propeller 1 2, protects the propeller 1 2 and the motor 1 1 and prevents a direct access to the propeller 12.

The lateral-propeller unit 1 0 further comprises an attachment part 1 6, through which the lateral-propeller unit is attached to the side pieces 33, 34 of the stern ladder. This attachment part 1 6 may constitute a separate part that is attached to the casing 1 3, as illustrated in Figs. 7 and 8. The attachment part 16 may alternatively constitute an integrated part of the casing 1 3, as illustrated in Figs. 9 and 1 0. The attachment part 16 is connected to one side piece 33 of the stern ladder by means of one or more first connecting members 1 7 and connected to the other side piece 34 of the stern ladder by means of one or more second connecting members 1 8. In the illustrated embodiments, said first connecting members 1 7 are yoke-shaped and two in number, and said second connecting members 1 8 are also yoke-shaped and two in number. Each connecting member 1 7, 18 extends over a side piece 33, 34 of the stern ladder and is at its two opposite ends attached to the attachment parts 1 6 by means of fastening elements 1 9 in the form of for instance screws or threaded bolts. The distance in the longitudinal direction of the lateral-propeller unit between said first connecting members 1 7 and said second connecting members 1 8 is with advantage adjustable for adjustment to the existing distance between the side pieces 33, 34 of the stern ladder. I n the embodiments illustrated in Figs. 7-1 0, this adjustability is achieved in that each connecting member 1 7, 1 8 is displaceable along an elongated groove 20A-D, which is arranged in the attachment part 16 and which extends in the longitudinal direction of the lateral-propeller unit. Each connecting member 1 7, 1 8 is in engagement with the fastening part 1 6 through two fastening elements 1 9 , each of which extendi ng through a hole in the connecting member 1 7, 1 8 and through the associated groove 20A-D in the attachment part 1 6.

I n the embodiment illustrated in Figs. 7 and 8, each connecting member 1 7, 1 8 is allotted a separate groove 20A-D in the attachment part 16 , the respective groove 20A-D extending over a limited part of the length of the attachment part. In the embodiment illustrated in Figs. 9 and 1 0, one first connecting member 1 7 and one second connecting member 1 8 are allotted a common first groove 20A in the attachment part 16, whereas another first connecting member 1 7 and another second connecting member 1 8 are allotted a common second groove 20B in the attachment part 1 6. I n the last-mentioned case, each groove 20A, 20B extends over the entire length of the attachment part.

In the embodiments illustrated in Figs. 7- 1 0, each fastening element 1 9 is a threaded bolt, which comprises a shaft 21 and a head 22 provided at one end of the shaft. In the embodiment illustrated in Figs. 7 and 8, the head 22 of each fastening element 1 9 abuts against an outwardly facing shoulder on the associated connecting member 17, 1 8, and the shaft 21 of the fastening element is provided with an external thread which is in engagement with an internal thread of a nut 23 or washer that abuts against an inwardly facing shoulder on the inner side of the associated groove 20A-D in the attachment part 16.

In the embodiment illustrated in Figs. 9 and 1 0, the head 22 of each fastening element 1 9 abuts against an inwardly facing shoul- der on the inner side of the associated g roove 20A, 20B in the attachment part 1 6, and the shaft 21 of the fastening element is provided with an external thread which is in engagement with an internal thread of a nut 23 that abuts against an outwardly facing shoulder on the associated connecting member 1 7, 1 8. The invention is of course not in any way limited to the embodiments described above. On the contrary, several possibilities to modifications thereof should be apparent to a person skilled in the art without thereby deviating from the basic idea of the inven- tion such as defined in the appended claims. The lateral-propeller unit 1 0 could for instance be pivotally connected to the stern ladder 30.

Claims

ims

A propeller arrangement for a sailing boat comprising:

- a lateral-propeller unit (10), which comprises a motor (1 1 ), preferably in the form of an electric or hydraulic motor, and a propeller (12) driven by the motor; and

- a holder element (30) which carries the lateral-propeller unit (10),

characterized in that the holder element (30) consists of a stern ladder which is intended to be attached to the transom of a sailing boat and which comprises two elongated and mutually parallel side pieces (33, 34), which are arranged at a distance from each other, and several mutually parallel rungs (35) distributed in the longitudinal direction of the stern ladder, which rungs extend between the two side pieces (33, 34) and are attached to these side pieces.

A propeller arrangement according to claim 1 , characterized in that:

- that the propeller arrangement (1 ) comprises an attachment (4) intended to mounted to the transom of a sailing boat; and

- that the stern ladder (30) is pivotally connected to the attachment (4), the stern ladder (30) being pivotable in relation to the attachment (4) between a lowered position, in which the lateral-propeller unit (10) is intended to be immersed in the water behind the sailing boat, and a raised position, in which the lateral-propeller unit (10) is intended to be located above the water surface.

A propeller arrangement according to claim 2, characterized in that the lateral-propeller unit (1 0) is mounted on the side of the stern ladder (30) that is intended to face inwards towards the hull of the sailing boat when the stern ladder (30) is in the lowered position. A propeller arrangement according to claim 2 or 3, characterized in that the stern ladder (30) at one end (31 ) is articulately attached to said attachment (4), and that the lateral- propeller unit (10) is mounted at the opposite other end (32) of the stern ladder.

A propeller arrangement according to any of claims 1 -4, characterized in that the lateral-propeller unite (10) comprises:

- an attachment part (16), through which the lateral-propeller unit (10) is attached to the side pieces (33, 34) of the stern ladder;

- one or more first connecting members (17) for connecting said attachment part (16) to one side piece (33) of the stern ladder; and

- one or more second connecting members (18) for connecting said attachment part (16) to the other side piece (34) of the stern ladder.

A propeller arrangement according to claim 5, characterized in that the distance in the longitudinal direction of the lateral- propeller unit between said first connecting members (17) and said second connecting members (18) is adjustable for adjustment to the distance between the side pieces (33, 34) of the stern ladder.

A propeller arrangement according to claim 6, characterized in that each first connecting member (17) is displaceable along an elongated groove (20A, 20B) which is provided in the attachment part (16) and which extends in the longitudinal direction of the lateral-propeller unit.

A propeller arrangement according to claim 7, characterized in that each first connecting member (17) is in engagement with the attachment part (16) through one or more fastening elements (19), each of which extending through the associated groove (20A, 20B) in the attachment part (16).

A propeller arrangement according to any of claims 6-8, characterized in that each second connecting member (18) is displaceable along an elongated groove (20C, 20D; 20A, 20B) which is provided in the attachment part (16) and which extends in the longitudinal direction of the lateral-propeller unit.

A propeller arrangement according to claim 9, characterized in that each second connecting member (18) is in engagement with the attachment part (16) through one or more fastening elements (19), each of which extending through the associated groove (20C, 20D; 20A, 20B) in the attachment part (16).

A propeller arrangement according to any of claims 1 -10, characterized in that the lateral-propeller unit (10) comprises a tubular casing (13), said motor (1 1 ) and propeller (12) being arranged in this casing (13).

A propeller arrangement according to claim 1 1 , characterized in that the lateral-propeller unit (10) is attached to the stern ladder (30) with the longitudinal axis of the tubular casing (13) extending essentially in parallel with the rungs (35) of the stern ladder.

13. A sailing boat, characterized in that a propeller arrangement (1 ) according to any of claims 1 -12 is arranged on the transom (2) of the sailing boat.