WO2009022956A1

WO2009022956A1 - Stem ladder

Info

Publication number: WO2009022956A1
Application number: PCT/SE2008/000467
Authority: WO
Inventors: Sten ASÉN
Original assignee: Lockia Security Solutions Ab
Priority date: 2007-08-15
Filing date: 2008-08-13
Publication date: 2009-02-19

Abstract

A stem ladder for a boat (1) comprising a ladder beam (4), which with one of the upper end parts thereof is swivellably connected to an upper end (21) of the stem (2) of the boat for swivelling in a vertical longitudinally central plane of the boat. The treads (41, 41') are carried on the ladder beam (4) for swivelling in a plane perpendicular to the longitudinally central plane and parallel to the longitudinal direction of the ladder beam, between a vertical folded-in storage state and a horizontal folded-out usage state. A bar (50) is arranged at the upper end part of the ladder beam (4), which bar is displaceably arranged between a projected active state and a folded-in inactive state, in the projected active state thereof, the bar allowing swivelling of the ladder beam (4) between the storage state thereof and the usage state thereof.

Description

Stem ladder

The invention relates to a stem ladder for a boat according to the preamble of claim 1.

Thus, the invention relates to a stem ladder for a boat, comprising a ladder beam, which with one of the upper ends thereof is swivellably connected to an upper end of the stem of the boat for swivelling in a vertical longitudinally central plane of the boat, the step beam carrying treads. More precisely, the stem ladder is intended to be fixedly mounted to the stem of the boat.

Such a previously known construction comprises a proper ladder, i.e., two parallel ladder beams having a series of rungs, which extend between them at mutual distance along the pair of ladder beams, the rungs extending in parallel to the swivel axis of the connection of the ladder to the boat.

Such constructions extend in a plane perpendicular to said longitudinally central plane of the boat. Therefore, the ladder is projecting from the outer surface of the hull of the boat, and may easily be damaged upon contact with landing- stages or the like. Furthermore, such a ladder will be exposed to, among other things, waves in the direction of travel of the boat in such a way that the ladder causes water splash and an increased propulsion resistance for the boat. Furthermore, the known ladder may be perceived as an aesthetically less attractive structural addition to the primary shape of the hull of the boat.

Therefore, the object of the invention is to provide a stem ladder by means of which the drawbacks just mentioned are entirely or partly obviated, and other advantages are attained, such as directly or indirectly are seen in the following description.

The object is attained by the invention.

The invention is defined in the characterizing part of claim

1.

Presently particularly preferred embodiments of the invention will in the following be described in the form of examples, reference being made to the appended drawing.

Figure 1 schematically shows a side view of the stem of a boat having a stem ladder according to the invention mounted thereon, in operative state.

Figure 2 schematically shows a section taken along line V-V.

Figure 3 shows a schematic view taken from above along line

HI-III in Figure 1. Figure 4 illustrates the stem ladder according to Figure 1 in a state folded in against the stem, with the rungs of the stem ladder folded 90° away from the operative states thereof but without skirts.

Figure 5 shows a view taken along line VI-VI in Figure 1. Figure β shows a view corresponding to Figure 5, but with the rungs turned 90° so as to lie aligned in parallel with the longitudinal direction of the stem ladder beam.

Figure 7 shows a view of another embodiment of rungs and swivel mounting for the same on the ladder beam. Figure 8 shows an additional embodiment of rungs and swivel mounting for the same on the ladder beam. Reference being made to Figure 1, it can be seen that the stem 2 of the boat 1 in the upper part 21 thereof has a suspension attachment 3 for a stem beam 4, which in the upper end thereof, by means of a swivel mounting 5, is connected to the attachment 3 for swivelling in a vertical longitudinally central plane. The beam 4 carries rungs 41, which in the operative state are horizontally directed, such as is shown in Figures 1 and 5. The rungs are arranged turnable on the beam 4 for swivelling around the longitudinally central points thereof and are therefore carried on each a shaft shank 42. The distance between the shaft shanks 42 is greater than the length of the rungs 41 so that these do not interfere with each other, when they are swivelled into inactive state i.e., parallel to the beam 4.

From Figure 1, it can be further seen that a staying arm 6 is, by a swivel mounting 7, connected to the beam 4 for swivelling from a storage state on and parallel to the inside of the beam 4 and a shown folded-out position in which the end of the arm 6 adjacent to the stem can be stayed, for instance, by means of a Y-shaped fork or the like, when the beam 4 depends vertically downward under impact of gravity.

As another alternative, the end of the arm 6 facing the stem 2 may be detachably connected to a fitting 8, which is actuatable, for instance, via a remote control, such as a haulage rope, for release of the adjacent arm end.

On the stem 2 under the fitting 8, there is shown a fixed fit- ting 9 having a projecting arm 91, which has a waist 92. On the beam 4, there is an appurtenant detachable carrying device, which can engage the fitting 9, when the beam 4 lies parallel to and next to the stem 2. On each side, the beam 4 carries a skirt 48, the skirts 48 diverging toward the stem 2 in order to form a screening between the beam and the respective side of the hull. The skirts 48, which may consist of relatively hard rubber, are intended to cover the space formed between the beam 4 and the stem 2, particularly when the stem is not straight, in the storage state of the stem ladder. To a certain extent, they also have the purpose of limiting the risk of the beam 4 swiv- elling out laterally, when it is swivelled in toward the stem 2.

In an embodiment not shown, the stem ladder may be integrated from factory in the stem of the boat, the skirts 48 preferably not being arranged.

From Figure 3, it can be understood that the attachment 3 has a general U-shape, the branches of the shape being attached to the sides of the hull next to the stem. The forward part of the attachment 3 receives the beam 4 and the mounting shaft 5. Furthermore, in Figure 3, it can be seen that a fixed or detachable foot plate/ladder plane 3a is arranged at the attachment 3. The beam 4 is shown to form a holder, which receives a bar 50, which can be pushed up over the attachment 3 to the active state thereof. A person standing on the deck

32 of the boat can grasp the bar 50 and swivel the same in the vertical centre plane of the boat, for swivelling the beam 4 to, on one hand, a storage state in correspondence to the depiction according to Figure 4 and, on the other hand, to an operative state in correspondence to the depiction according to Figure 1. Another purpose of the bar 50 is that it, in the projecting position thereof, serves as a handle in order to facilitate a person's getting on and off the stem ladder. In Figure 4, it can be seen that the bar 50 may have an inactive storage state pushed down in the beam 4.

It should be mentioned that in Figure 4, the skirts 48 on the respective side of the beam 4 are not shown.

Reference being made to Figure 2, it can be seen that the beam 4 is in the form of a box beam, each longitudinal mounting shaft 42 for a rung 41 carrying a coaxial transmission wheel 43, for instance a cogwheel 144, said transmission wheels being interconnected in pairs with an endless circumferential belt or transmission chain 44 for synchronous and parallel turning motion. Furthermore, the beam 4 is shown to contain a manually actuatable rotatably mounted operating reel 143 having a coaxial cogwheel. An endless belt or transmission chain 145 extends around the cogwheels 144, whereby the rungs synchronously can be turned using the operating reel 143. Furthermore, it can be seen that each shaft shank 42 also carries a disc 52 axially displaced from the cogwheel 43. Each disc 52 has two plane circumference surfaces adjacent to each other, which are parallel to the shaft shank 42 and which mutually form a right angle. The circumference of the discs 52 between the planed areas 53, 54 has a greater radius than the smallest radial distance from the surfaces 53, 54 to the geometrical centre of the shaft 42.

Furthermore, in Figure 2 a row of trapezoid wedges 60 are shown, which have a top surface lying next to the surface 54 of the respective disc 52, when the rungs 41 are in the horizontal orientation. Thus, the wedges 60 lock the rungs 41 in said orientation. In Figure 2, it can be seen that the wedges 60 are interconnected to each other via, e.g., a rope 61. It can be seen that the lower end of the rope 61 is via a spring 62 coupled to a fixed point 63 on the beam 4. Furthermore, it can be seen that the rope 60 extends up through an opening of the upper end of the beam 4 and is connected to a hand grip 65. Thus, an operator can manually seize the hand grip 65 and lift the rope 61 so that the wedges 60 go out of engagement with the surfaces 54 of the discs 52. Thereby, it is possible to, using the operating reel 143, rotate the rungs 41 so that the same extend along the beam 4, such as is shown in Figure 4. The operator can then disengage the hand grip 65 whereupon the wedges 60 under the impact of the spring 62 will be pulled down so that their locking surface will closely border to a respective surface 53 of the discs 52 and thereby lock the rungs in the orientation in question.

From Figure 2, there can furthermore be seen a detachable locking device 104, which co-operates with the fitting 9 in Figure 1, when the beam 4 is swivelled in toward the stem 2 after the arm 6 having been folded in toward the side of the beam 4 facing the stem 2. In that connection, the locking device 4 has an opening 105 in which the arm 91 of the fitting 9 is received. The locking device 104 comprises further a sleeve 106, generally directed along the beam 4, which sleeve receives a lock bolt 107 slidingly guided therein and receiv^¬ able in the waist 92 of the arm 91. The bolt 107 is shown biased in the downward direction in Figure 2 by a tension spring 108. To the upper end of the bolt 107, a haulage rope 110 connects, which extends up through an appurtenant opening in the upper end of the beam 4 and connects to the hand grip 165. An operator can, by pulling the hand grip 165 in the upward direction, expose the opening 105 so that the arm 91 can be inserted therein. By unloading of the hand grip 65, the spring 108 will pull the lock bolt 107 down into the waist 92 of the arm 91, whereby the beam 4 can be secured in the swivelling end position according to Figure 4.

Figure 7 shows, in a view corresponding to Figure 5, another embodiment of the design and swivel mounting of the rungs. In Figure 7, on each level along the beam 4, a pair of rungs 41' are shown, each one of which is by means of a friction swivel mounting 200 swivel mounted to a respective side surface of the beam 4 before swivelling in a plane perpendicular to the vertical longitudinally central plane of the boat, between an active state (shown by solid lines) and a storage state illustrated by dashed lines. The swivel mounting 200 affords manual swivelling of the rungs 41 between their end positions, and by the built-in friction of the swivel mounting 200, the rungs 41' retain a state in which they are unloaded. From Figure 7, it can be understood that the end surfaces of the rungs 41 are situated below the level of the respective swivel mounting 200 and come to inelastic abutment against the adjacent side surface of the beam 4, when the rung 41' is horizontally orien- tated.

In other feasible embodiments, the rungs 41' may be mutually swivel-coupled by a transmission, connected with a controller for common movement between the end positions, wherein the swivel mountings 200 do not necessarily need to be of the type indicated above, which retains the rungs 41' in the set swivelling position upon unloading. An example of such an embodiment is shown in Figure 8. An operating rod 201 is arranged by means of which it is convenient and safe to actuate the rungs 41' from the stem of the boat. The operating rod actuates a transmission 203, 204 displaceably arranged between two end positions, the first end position of which is shown by solid lines, in which the rungs are folded-out (the rungs shown by solid lines) , and the other end position of which is shown by dashed lines, in which the rungs are folded- in (the rungs shown by dashed lines) . It should be mentioned that only one transmission 203, 204 is shown in the Figure for two rungs 41' arranged at the same axial distance on the beam 4 from the attachment 3. Mountings 202 are arranged on suitable spots in the beam 4, so that the operating rod can be displaced axially along the beam 4. A stop member 205 is arranged on the operating rod 201 for fixation of the operating rod in the folded-out or folded-in position of the rungs 41' . The arms included in the transmission 203, 204 have tracks, which enable that they can move between the two end positions .

Claims

1. A stem ladder for a boat (1) comprising a ladder beam (4), which with one of the upper end parts thereof is swivellably connected to an upper end (21) of the stem (2) of the boat for swivelling in a vertical longitudinally central plane of the boat, the ladder beam (4) carrying rungs (41, 41') , the rungs (41, 41') being carried on the ladder beam (4) for swivelling in a plane perpendicular to the longitudinally central plane and parallel to the longitudinal direction of the ladder beam, between a folded-in storage state substantially parallel to the longitudinal direction of the stem and a substantially horizontal folded-out usage state, characterized in that a bar (50) is arranged at the upper end part of the ladder beam (4), which bar is displaceably arranged between a projected active state and a folded-in inactive state, in the projected active state thereof, the bar allowing swivelling of the ladder beam (4) between the storage state thereof and the usage state thereof.

2. Stem ladder according to claim 1, characterized in that the ladder beam (4) on each side carries a skirt (48), the skirts diverging toward the stem (2) in order to form a screening between the ladder beam and the respective side of the hull in order to cover a space, formed between the ladder beam (4) and the stem in the storage state of the ladder beam.

3. Stem ladder according to claim 1 or 2, characterized in that a stay arm (6) is swivel mounted on the ladder beam (4) on the side thereof facing the stem for swivelling between an orientation in which the arm (6) extends parallel to and next to the ladder beam (4), and a folded-out position in which the arm (6) supportingly can engage the stem (2) when the ladder beam (4) has assumed an essentially vertical orientation .

4. Stem ladder according to any one of the preceding claims, characterized by a detachable locking device (9, 104) for detachable retention of the ladder beam (4) parallel to and next to the stem (2) .

5. Stem ladder according to any one of the preceding claims, characterized in that the rungs (41) are coupled to each other by means of a transmission (43, 44) for synchronous swivelling between swivelling end positions, that a detachable locking device (60-65) is provided in order to allow locking of the rungs in the respective swivelling end position, and that an operating device (143, 144, 145) is provided for common driving of the rungs via the transmission when the locking device is unlocked.

6. Stem ladder according to any one of claims 1-4, characterized in that the rungs (41') are swivel mounted to the respective side of the ladder beam (4) for swivelling between a folded-down horizontally directed position and a folded-up position wherein the rungs are directed parallel to the ladder beam and extend parallel to the ladder beam.

7. Stem ladder according to claim 6, characterized in that the swivel mountings (200) of the rungs (41') are friction mountings, which retain the rungs (41) in a swivelling state in which they are unloaded.

8. Stem ladder according to claim 6, characterized in that an operating rod (201) is arranged along the ladder beam (4) and arranged to actuate the rungs (41') via a transmission (203,204) displaceably arranged between two end positions, the rungs (41'), in one end position of the transmission, being directed in parallel to the ladder beam and in the other end position perpendicularly to the ladder beam.

9. Stem ladder according to claim 8, characterized in that the transmission (203,204) comprises two arms, each one of which is provided with a track, which enables that the arms can move between the two end positions.

10. Stem ladder according to any one of claims 1-9, characterized in that a fixed or detachable foot plate (3a) is arranged at an attachment (3) for the receipt of the ladder beam (4 ) .

11. Stem ladder according to any one of claims 1-10, characterized in that it is integrated in the stem of the boat .