PULL-IN DEVICE FOR A TOWLINE

Abstract

A pull-in device for a towline (31) arranged to connect a towable object (2) to a towing vessel (1), in which a reel (323) which is arranged to receive the towline (31) is arranged in a reeling device (32) fixed to the towing vessel (1), and in which the reeling device (32) is provided with a pull-in controller (325) arranged to selectably provide a rotationally rigid connection between a tensioning handle (33) and a pull-in spring (324), alternatively a rotationally rigid connection between the pull-in spring (324) and the towline reel (323).

Description

A pull-in device for a towline arranged to connect a towable object to a towing vessel is described, in which a reel which is arranged to receive the towline is arranged in a reeling s device fixed to the towing vessel, wherein the reeling device being provided with a pull-in controller arranged to selectably provide a rotationally rigid connection between a tensioning handle and a pull-in spring, alternatively a rotationally rigid connection between the pull-in spring and the towline reel.

When a dinghy or the like is towed behind a pleasure boat or some other small craft, and when water sport, such as water-skiing or the like, is being practised, there is often a risk that a towline will get caught in the propeller of the towing craft when the speed of propulsion of the craft is reduced without the slack of the towline being eliminated. This both entails a risk of the craft losing its manoeuvrability, which may entail the risk of it being wrecked, and often entails the need for assistance from a frogman to free the propeller of the stuck line. A line of the kind used in towing is usually of a given length, one end being attached to the object being towed, whereas the other end is attached to the towing vessel. The length of the towline is adjusted to the relevant towing operation to be performed. To reduce the risk of the towline catching in the propeller, it is normal that personnel on the object towed or on the towing vessel hauls in slack whenever such occurs.

There is a need for a device which can prevent the towline from getting caught in the propeller as the speed of s propulsion of the towing vessel is reduced.

The invention has for its object to remedy or reduce at least one of the drawbacks of the prior art.

The object is achieved through features which are specified in the description below and in the claims that follow.

The invention provides a pull-in device for a towline, arranged to automatically keep the towline taut and, at the same time, apply a pulling force to the towline, adjusted to the drag of the object being towed, in order thereby to avoid pulling the towed object in towards the towing vessel during interruptions to the towing operation. This is achieved by the towline being attached to a reel, on which the towline can be accommodated substantially in its entirety. To the reel is connected a pull-in spring which can be pre-tensioned to a prescribed level by means of a pull-in controller. This can be operated by means of an operating handle or the like, and the pre-tensioning setting is indicated easily visible to the operator. In principle, the setting is carried out by the pull-in spring being disengaged temporarily from the towline reel and then being tensioned or slacked before being reconnected to the towline reel. This adjustment can be carried out by the pull-in controller being provided with an operable coupling actuator which disconnects, when activated, a spring axle from a concentric adjacent reel-axle rotation by axial movement of the reel axle relative to the spring axle, subsequent rotation of the spring axle and finally axial movement of the reel axle into engagement with the spring axle. The reel and spring axles may be releasably engaged by means of one or more claw couplings.

The pull-in device may be provided with several entrance ports for the towline in order thereby to provide alternative mounting positions. The towline may be provided with a stop which is movable in the longitudinal direction of the towline and at least arranged to rest against a portion of the pull-in device adjacent to the entrance port, preferably arranged as a wedge projecting at least partially into the entrance port for the adjacent structure of the entrance port to apply a clamping force to the stop, ensuring a good connection between the stop and the towline.

The invention relates more specifically to a pull-in device for a towline arranged to connect a towable object to a towing vessel, in which a reel which is arranged to receive the towline is arranged in a reeling device which is fixed to the towing vessel, characterized by the reeling device being provided with a pull-in controller arranged to selectably provide a rotationally rigid connection between a tensioning handle and a pull-in spring, alternatively a rotationally rigid connection between the pull-in spring and the towline reel.

The pull-in controller may comprise a coupling actuator arranged to move a reel axle, which is rotationally rigidly connected to the towline reel, axially relative to a spring axle which is rotationally rigidly connected to the pull-in spring.

The axial travel of the reel axle may be defined by first and second coupling springs arranged concentrically on the extensions of the reel axle.

The rotationally rigid connections between, respectively, the tensioning handle and the pull-in spring and the pull-in spring and the towline reel, may be provided by means of claw couplings arranged axially.

The pull-in controller may be provided with a tension indicator arranged to indicate visually the degree of tensioning of the pull-in spring.

The towline may be provided with a stop device which is movable in the longitudinal direction of the towline and is arranged to project partially into an entrance port arranged at the periphery of the towline reel.

The reeling device may be provided with a casing including an attachment arranged to attach the pull-in device to the towing vessel.

The attachment is formed as a hull attachment arranged to be attached to a hull structure on the towing vessel.

The attachment may be formed as an elongated body arranged to grip a mooring cleat on the towing vessel.

The casing may be provided with several entrance ports.

At least one entrance port can be arranged to drain liquid from the casing.

In what follows is described an example of a preferred embodiment which is visualized in the accompanying drawings, in which:

FIG. 1 a shows a side view of a towing vessel connected to a towable object via a prior-art towline, the towable objecting having moved towards the towing vessel because of the propulsion of the towing vessel having ceased;

FIG. 1 b shows a situation corresponding to the one in FIG. 1a, but in which the towline is attached to a pull-in device according to the invention;

FIG. 2 shows, in perspective, a pull-in device according to the invention;

FIG. 3 shows a partially cutaway perspective view of the pull-in device;

FIG. 4 shows, in exploded perspective, a coupling actuator and a tension indicator on an enlarged scale relative to the pull-in device;

FIG. 5 shows, on a smaller scale, an exploded perspective of the pull-in device;

FIG. 6 shows parts of the pull-in controller; and

FIG. 7 a-h show alternative attachments of the pull-in device.

In FIGS. 1a and 1b, the reference numeral 1 indicates a towing vessel connected to a towable object 2 (shown here as a smaller craft) by means of a towline 31. In a first end portion 311, the towline 31 is provided with a fastening device 313 (see FIG. 2) arranged for releasable connection to the object 2 towed, for example in the form of a snap hook. According to the prior art, a second end portion 312 of the towline 31 is attached to a suitable area on the towing vessel 1, typically to a cleat 11.

According to the invention, as it is indicated in FIG. 1b, the second end portion 312 is attached to a towline pull-in device 3, in which a reeling device 32 (see FIG. 2 and following figures) is provided with a casing 321 accommodating inter alia a towline reel 323 arranged to receive substantially the entire towline 31. Advantageously, the towline 31 is formed as a woven band which is easily guided onto the reel 323. The towline reel 323 is rotationally rigidly arranged on a tubular reel axle 325a which is provided with a first claw coupling 325b.

A tubular spring axle 325c is arranged to fix a first end portion of a pull-in spring 324. The pull-in spring is coil-shaped and is fixed, at a second end portion (not shown), to a peripheral portion of the casing 321. At a first end portion, the spring axle 325c is provided with a second claw coupling 325d which is complementary to the first claw coupling 325b on the reel axle 325a. At a second end portion, the spring axle 325c is provided with a third claw coupling 325e.

Rotatable and axially movable, the reel axle 325a and the spring axle 325c are arranged on a cylindrical coupling stem 325n which is supported at its end portions in a second side surface 321b of the casing 321 and a coupling actuator 325h, respectively.

A first coupling spring 325f surrounds a first portion of the coupling stem 325n, bearing against the reel axle 325a opposite the first claw coupling 325b and against a shoulder in the coupling stem 325n adjacent to the second side surface 321b of the casing 321, and is arranged to apply a push force to the reel axle 325a in the direction towards the spring axle 325c.

A second coupling spring 325g surrounds a second portion of the coupling stem 325n (in FIG. 6, shown separated from the coupling stem 325n) and bears against the reel axle 325a at the first claw coupling 325b, more particularly against a shoulder (not shown) arranged radially within the first claw coupling 325b. At the opposite end portion, the second coupling spring 325g bears on the coupling actuator 325h. A portion of the second coupling spring 325g is surrounded by the spring axle 325c.

The coupling actuator 325h comprises a spring-loaded rotary element 325i which is arranged, when moved axially, to engage a coupling unit 325j in a rotationally rigid manner and move the coupling unit 325j axially into rotationally rigid engagement with the spring axle 325c. A tension indicator 325k is connected in a rotationally rigid manner to the coupling unit 325j and exhibits means for visual indication of the rotation of the coupling unit 325j relative to the casing 321.

The rotary element 325i is provided with a polygonal countersink 325m arranged for releasable engagement with a tensioning handle 33 (see FIG. 2).

The casing 321 is provided with a portion arranged to be connected to an attachment 326 to fix the reeling device 32 in a suitable place on the towing vessel 1. In an exemplary embodiment (see FIG. 7a-d), the attachment 326 is formed as a hull attachment 326a, for example a plate, arranged to rest permanently in a supported manner against a portion of the towing vessel 1. In another exemplary embodiment (see FIG. 7e), the attachment is formed as an elongated, hoop-shaped attachment 326b arranged to releasably grip a mooring cleat 11 or the like on the towing vessel 1. In this embodiment, the attachment 326b is appropriately formed with a padding 326c.

The casing 321 is provided with an entrance port 322 for the towline 31. Alternatively, the entrance port 322 is formed in the hull attachment 326a. The casing 321 may alternatively include several entrance ports 322 for the best possible adaptation of the towline entrance to the preferred mounting position of the reeling device 32. An entrance port 322 facing downwards in the position of use could appropriately function as a drain opening for water entrained into the casing 321 by the towline 31.

The towline 31 is provided with a stop 314 arranged to be moved in the longitudinal direction of the towline 31. The stop 314 is appropriately formed of flexible material and is wedge-shaped. The stop 314 can thereby project, at least partially, into the entrance port 322 and, by its wedge shape, be pressed against the towline 31 in order thereby to lock the towline 31, preventing it from being reeled in more than appropriately.

The pull-in device 3 is mounted in a suitable place on the towing vessel 1. When a towing operation is to be carried out, the pulling force of the pull-in device 3 is checked, the tensioning of the pull-in spring 324 being read on the tension indicator 325k. If the reading is not in accordance with the desired setting for that kind of towing operation, for example according to experience or according to the manufacturer's recommendation, preferably indicated by a symbol, possibly in accompanying instructions, based on the size and hydrodynamic properties etc. of the object 2 towed, the pull-in controller 325 is adjusted by the tensioning handle 33 being connected to the coupling actuator 325h as the handle 33 is moved into engagement in the polygonal countersink 325m of the rotary element 325i. By moving the rotary element 325i axially inwards, the coupling actuator 325h pushes the second coupling spring 325g in the direction towards the towline reel 323, applying a radially directed push force to the first coupling spring 325f. The reel axle 325c is thereby released from engagement with the spring axle 325c while, at the same time, the coupling actuator 325h engages the spring axle 325c in a rotationally rigid manner. Then the spring tensioning is adjusted by the tensioning handle 33 being rotated until the tension indicator 325k shows the desired value. Then the coupling actuator 325h is deactivated as the rotary element 325i is moved back into its initial position, the pressure of the second coupling spring 325g against the reel axle 325a ceases, and the first coupling spring 325f pushes the reel axle into engagement with the spring axle 325c as the coupling actuator 325h is simultaneously disengaged from the spring axle 325c.

The coupling actuator 325h is preferably of a kind that provides a state of locked engagement as the rotary element 325i is pushed into its pushed-in end position and the pushing force is removed, and neutralization of the locking is achieved by the rotary element 325i again being pushed inwards and then being released into its initial position, corresponding to the functionality of a push-button function known from an ordinary ball-point pen.

The FIGS. 7a and 7b show alternative positions of the pull-in device 3.

FIG. 7 c shows outside mounting on a side surface of the hull of the vessel 1.

FIG. 7 d shows a flush mounting in a side surface of the hull of the vessel 1.

The FIGS. 7e and 7f show a built-in mounting in which, in an inactive state, the pull-in device 3 is hidden behind a hatch 12.

FIG. 7 g shows elements for attaching the pull-in device 3 to a cleat 11, an elongated cleat attachment 326b being arranged to be attached to the casing 321 of the pull-in device 3 and being passed around the cleat 11. Padding elements 326c are arranged to enclose parts of the cleat attachment 326b to prevent damage to the hull of the towing vessel 1.

FIG. 7 h shows the pull-in device 3 attached to the cleat 11.

Claims

1. A pull-in device for a towline arranged to connect a towable object (2) to a towing vessel the pull-in device comprising: a reeling device fixed to the towing vessel;a reel which is arranged to receive the towline (31) wherein the reel is arranged in the reeling device; anda pull-in controller connected to the reeling device and arranged to selectably provide one of a rotationally rigid connection between a tensioning handle and a pull-in spring and a rotationally rigid connection between the pull-in spring and the towline reel.

2. The pull-in device of claim 1, wherein the pull-in controller includes a coupling actuator arranged to axially move a reel axle wherein the reel axle is rotationally rigidly connected to the towline reel, relative to a spring axle which is rotationally rigidly connected to the pull-in spring.

3. The pull-in device of claim 1, wherein axial travel of the reel axle is defined by a first coupling spring and a second coupling spring and further wherein a reel axle is rotationally rigidly connected to the towline reel relative to a spring axle which is rotationally rigidly connected to the pull-in spring wherein the first coupling spring and the second coupling spring are arranged concentrically on extensions of the reel axle.

4. The pull-in device of claim 1, wherein the rotationally rigid connection between the tensioning handle and the pull-in spring and the rotationally rigid connection between the pull-in spring and the towline reel, are provided by claw couplings arranged axially.

5. The pull-in device of claim 1, wherein the pull-in controller has a tension indicator arranged to indicate visually the degree of tensioning of the pull-in spring.

6. The pull-in device of claim 1, wherein the towline has a stop which is movable in the longitudinal direction of the towline and is arranged to partially project into an entrance port arranged at the periphery of the towline reel.

7. The pull-in device of claim 1, wherein the reeling device has a casing which includes an attachment arranged to fix the pull-in device to the towing vessel.

8. The pull-in device of claim 7, wherein the attachment is formed as a hull attachment arranged to be fixed to a hull structure of the towing vessel.

9. The pull-in device of claim 7, wherein the attachment is formed as an elongated body arranged to grip a mooring cleat on the towing vessel.

10. The pull-in device of claim 7, wherein the casing is provided with entrance ports.

11. The pull-in device of claim 10, wherein at least one of the entrance ports is arranged to drain liquid from the casing (321).