EP4112438A1

EP4112438A1 - Extensible ladder and boat comprising said extensible ladder

Info

Publication number: EP4112438A1
Application number: EP22182016.0A
Authority: EP
Inventors: Alfonso Branca
Original assignee: New Glass Composites Srl
Current assignee: New Glass Composites Srl
Priority date: 2021-06-30
Filing date: 2022-06-29
Publication date: 2023-01-04
Also published as: IT202100017288A1

Abstract

The present invention relates to a ladder comprising a first and a second fixed handrail (2a, 2b) each of which has an elongated body (3), a predetermined number of rungs (4) transversely engaged with the first and second fixed handrails (2a, 2b) and at least one extensible handrail (5a) engaged to the elongated body (3) of the first fixed handrail (2a). The extensible handrail (5a) can be positioned relative to the first fixed handrail (2a) at least between a first operative condition, in which the extensible handrail (5a) is movable along at least a portion of the elongated body (3) of the first fixed handrail (2a), and a second operative condition, in which the extensible handrail (5a) interferes with at least one rung (4) which limits or prevents the mobility along the elongated body (3) of the first fixed handrail (2a). The present invention also relates to a boat comprising said ladder.

Description

FIELD OF THE INVENTION

The present invention relates to an extensible ladder, in particular installable inside an under-deck access well of a boat. In particular, the present invention relates to ladders with extensible handrails useful for facilitating access to wells of boats.
The present invention also relates to a boat comprising said extensible ladder installed inside the under-deck access wells of the boat itself.

PRIOR ART

As is known, there are on the market ladders with extensible uprights which facilitate the passage of a user through wells or manholes.
An extensible ladder, described in patent application KR 20140049239 A , comprises hollow tubular handrails within which an extensible ladder is housed. Each fixed tubular handrail has a curvilinear groove configured to house a pin constrained to the extensible ladder and guide the sliding and rotation of the extensible ladder externally to a well.
A drawback highlighted by this type of extensible ladders is given by the use of a movable pin for sliding inside a guide, which is unsuitable for use in maritime environments. In fact, the formation of deposits and/or encrustations between the fixed handrail and the removable handrail or at the guide groove of the pin jeopardizes the functioning of the ladder, for example by limiting or preventing the sliding of the extensible handrail along the groove, or preventing it from locking, thus reducing the operational reliability of the ladder.

OBJECT OF THE INVENTION

It is therefore the object of the present invention to solve at least one of the drawbacks and/or limitations of the above solutions.
A first object of the present invention is to provide a ladder having a simple and compact structure capable of minimizing the overall dimensions.
A further object of the present invention is to provide a ladder which can be easily installed within the narrow spaces typical of the wells of boats.
Another object of the invention is to provide a ladder which is able to operate without functional problems even in aggressive environments such as the marine environment.
A further object of the present invention is to provide a ladder which has a high degree of reliability and which requires a reduced number of maintenance interventions.
These objects and others, which will become more apparent from the following description, are substantially achieved by a ladder according to one or more of the appended claims and/or the following aspects.

SUMMARY

Aspects of the invention are described hereinafter.
In a 1st aspect, a ladder is provided comprising:

a first and a second fixed handrail (2a, 2b) each of which has an elongated body (3) extending between a lower end and an upper end (3a, 3b),
a pre-set number of rungs (4) transversely engaged to the first and to the second fixed handrail (2a, 2b),
at least one extensible handrail (5a) engaged to the elongated body (3) of the first fixed handrail (2a),

a first operative condition in which the extensible handrail (5a) is movable along at least one portion of the elongated body (3) of the first fixed handrail (2a), and
a second operative condition in which the extensible handrail (5a) is configured to interfere with at least one rung (4) which limits or hinders the mobility thereof along the elongated body (3) of the first fixed handrail (2a).

In a 2nd aspect according to the preceding aspect, the ladder comprises an auxiliary extensible handrail (5b) engaged to the elongated body (3) of the second fixed handrail (2b), wherein the auxiliary extensible handrail (5b) is positionable relative to the second fixed handrail (2b) at least between:

a first operative condition in which the auxiliary extensible handrail (5b) is movable along at least one portion of the elongated body (3) of the second fixed handrail (2b),
a second operative condition in which the auxiliary extensible handrail (5b) is configured to interfere with at least one rung (4) which limits or hinders the mobility thereof along the elongated body (3) of the second fixed handrail (2b).

In a 3rd aspect according to any one of the preceding aspects, the extensible handrail (5a) has at least one first constraint element (6a) slidably engaged to the elongated body (3) of the first fixed handrail (2a).
In a 4th aspect according to any one of the preceding aspects, the auxiliary extensible handrail (5b) has at least one second constraint element (6b) slidably engaged with the elongated body (3) of the second fixed handrail (2b).
In a 5th aspect according to any one of the preceding aspects, the extensible handrail (5a) comprises two or more first constraint elements (6a) slidably engaged at distinct portions of the elongated body (3) of the first fixed handrail (2a).
In a 6th aspect according to any one of the preceding aspects, the auxiliary extensible handrail (5b) comprises two or more second constraint elements (6b) slidably engaged at distinct portions of the elongated body (3) of the second fixed handrail (2b).
In a 7th aspect according to any one of the preceding aspects from the 3rd to the 6th, each of said first and second constraint elements (6a, 6b) has:

a main body (7) transversely engaged to the extensible handrail (5a) or with the auxiliary extensible handrail (5b),
a first and a second arm (7a, 7b) projecting as an extension of the main body, distinct and spaced from each other; and in which an intermediate space (8) is defined between respective ends of the first and of the second arm (7a, 7b) opposite the main body (7).

In an 8th aspect according to the preceding aspect, the first and the second arm (7a, 7b) of each constraint element extend along respective curvilinear trajectories having mutually facing concavities. In a 9th aspect according to any one of the two preceding aspects, the main body (7) of the constraint element (6) defines, in transverse section and in cooperation with said first and second arm (7a, 7b), a convex shape, for example substantially C or U-shaped.
In a 10th aspect according to any one of the three preceding aspects, the first and the second arm (7a, 7b) of the first constraint element (6a) define a seat (20) configured to at least partially house the elongated body (3) of the first fixed handrail (2a).
In an 11th aspect according to any one of the four preceding aspects, the first and the second arm (7a, 7b) of the second constraint element (6b) define a seat (20) configured to at least partially house the elongated body (3) of the second fixed handrail (2b).
In a 12th aspect according to any one of the two preceding aspects, the seat (20) of the first constraint element (6a) has, in cross-section, a predominant portion of the profile thereof complementarily shaped with respect to a perimeter profile of the cross-section of the elongated body (3) of the first fixed handrail (2a).
In a 13th aspect according to any one of the two preceding aspects, the seat (20) of the second constraint element (6b) has, in cross-section, a predominant portion of the profile thereof complementarily shaped with respect to a perimeter profile of the cross-section of the elongated body (3) of the second fixed handrail (2b).
In a 14th aspect according to any one of the preceding aspects from the 7th to the 13th, the main body (7) of a respective first and second constraint element (6a, 6b) defines, in cooperation with the first and the second arm (7a, 7b), a single rigid body.
In a 15th aspect according to any one of the preceding aspects from the 10th to the 14th, the intermediate space (8) of the first constraint element (6a) is configured to prevent the removal of the elongated body (3) of the first fixed handrail (2a) from the seat (20).
In a 16th aspect according to any one of the preceding aspects from the 11th to the 15th, the intermediate space (8) of the second constraint element (6b) is configured to prevent the removal of the elongated body (3) of the second fixed handrail (2b) from the seat (20).
In a 17th aspect according to any one of the preceding aspects from the 7th to the 16th, the opposite ends of the first and second arm (7a, 7b) of the first constraint element (6a) are arranged at a minimum distance smaller than the minimum overall dimension of the cross-section of the elongated body of the first fixed handrail (2a).
In an 18th aspect according to any one of the preceding aspects from the 17th to the 17th, the opposite ends of the first and second arm (7a, 7b) of the second constraint element (6b) are arranged at a minimum distance smaller than the minimum overall dimension of the cross-section of the elongated body of the first fixed handrail (2b).
In a 19th aspect according to any one of the preceding aspects from the 7th to the 18th, the elongated body (3) of the first and of the second fixed handrails (2a, 2b) has a circular-shaped cross-section with a diameter larger than the minimum distance between the first and the second arm (7a, 7b) of the first and of the second constraint element.
In a 20th aspect according to any one of the preceding aspects from the 7th to the 19th, the intermediate space (8) of the first constraint element (6a), in the first operative condition of the extensible handrail (5a), is configured to receive the rungs (4) passing through.
In a 21st aspect according to any one of the preceding aspects from the 7th to the 20th, the intermediate space (8) of the second constraint element (6b), in the first operative condition of the auxiliary extensible handrail (5b), is configured to receive the rungs (4) passing through.
In a 22nd aspect according to any one of the preceding aspects from the 7th to the 21st, the opposite ends of said first and second arm (7a, 7b) of the first and of the second constraint element (6a, 6b) are arranged at a minimum distance greater than a maximum overall dimension of the cross-section of each rung (4).
In a 23rd aspect according to any one of the preceding aspects, the extensible handrail (5a), at least during the transition between the first and second operative condition, is rotatably movable around the elongated body (3) of the first fixed handrail (2a).
In a 24th aspect according to any one of the preceding aspects, the auxiliary extensible handrail (5b), at least during the transition between the first and the second operative condition, is rotatably movable around the elongated body (3) of the second fixed handrail (2b).
In a 25th aspect according to any one of the preceding aspects, the first constraint element (6a), in the second operative condition of the extensible handrail (5a), is arranged in contact with, optionally above, a rung (4).
In a 26th aspect according to any one of the preceding aspects, the second constraint element (6b), in the second operative condition of the auxiliary extensible handrail (5b), is arranged in contact with, optionally above, a rung (4).
In a 27th aspect according to any one of the preceding aspects, the first and second fixed handrails (2a, 2b) extend along mutually parallel directions.
In a 28th aspect according to any one of the preceding aspects, the extensible handrail (5a) extends along an axis (X) parallel and adjacent to the first fixed handrail (2a), and wherein the auxiliary extensible handrail (5b) extends along a axis (X) parallel and adjacent to the second fixed handrail (2b).
In a 29th aspect according to any one of the preceding aspects, the extensible handrail (5a) has at least one respective stop element (9) configured to interfere, at least in the second operative condition of the extensible handrail (5a), with a rung (4) and at least partly prevent the rotation of the extensible handrail (5a) around the elongated body (3) of the first fixed handrail (2a).
In a 30th aspect according to any one of the preceding aspects, the auxiliary extensible handrail (5b) has at least one respective stop element (9) configured to interfere, at least in the second operative condition of the auxiliary extensible handrail (5b), with a rung (4) and at least partly prevent the rotation of the auxiliary extensible handrail (5b) around the elongated body (3) of the second fixed handrail (2b).
In a 31st aspect according to any one of the preceding aspects, each stop element (9) of the extensible handrail (5a) comprises at least one relief, optionally a pin, projecting transversely from the first constraint element (6a), optionally projecting transversely from at least one of said first and second arm (7a, 7b).
In a 32nd aspect according to any one of the preceding aspects, each stop element (9) of the auxiliary extensible handrail (5b) comprises at least one relief, optionally a pin, transversely projecting from the second constraint element (6b), optionally transversely projecting from at least one of said first and second arm (7a, 7b).
In a 33rd aspect according to any one of the preceding aspects from the 29th to the 32nd, at least one rung (4), in the second operative condition of the extensible handrail (5a), is interposed between the stop element (9) of the first constraint element (6a) and the extensible handrail (5a).
In a 34th aspect according to any one of the preceding aspects from the 30th to the 33rd, at least one rung (4), in the second operative condition of the auxiliary extensible handrail (5b), is interposed between the stop element (9) of the second constraint element (6b) and the auxiliary extensible handrail (5b).
In a 35th aspect according to any one of the preceding aspects from the 29th to the 34th, the stop element (9) of the first constraint element (6a) comprises a first and a second stop element (9a, 9b) which are distinct and spaced from each other.
In a 36th aspect according to any one of the preceding aspects from the 29th to the 35th, the first and the second stop element (9a, 9b) define a seat (10) which, at least in the second operative condition of the extensible handrail (5a), is configured to receive a rung (4) inserted thereinto.
In a 37th aspect according to any one of the preceding aspects from the 30th to the 36th, the stop element (9) of the second constraint element (6b) comprises a first and a second stop element (9a, 9b) distinct and spaced from each other, said first and second stop element (9a, 9b) defining a seat (10) which, at least in the second operative condition of the auxiliary extensible handrail (5b), is configured to receive a rung (4) inserted thereinto.
In a 38th aspect according to any one of the preceding aspects from the 35th to the 37th, the first and the second stop element (9a, 9b) of each of said first and second constraint element (6a, 6b) are arranged at a minimum distance greater than a maximum overall dimension of the cross-section of each rung (4).
In a 39th aspect according to any one of the preceding aspects, the first constraint element (6a) is configured so that the displacement of the extensible handrail (5a) from the second to the first operative condition occurs after the displacement of the extensible handrail (5a) transversely to said rungs, in particular parallel to the first fixed handrail, so as to disengage the rung (4) from the seat (10) of the first constraint element (6a).
In a 40th aspect according to any one of the preceding aspects, the second constraint element (6b) is configured so that the displacement of the auxiliary extensible handrail (5b) from the second to the first operative condition occurs after the displacement of the auxiliary extensible handrail (5b) transversely to said rungs, in particular parallel to the second fixed handrail, so as to disengage the rung (4) from the seat (10) of the second constraint element (6b).
In a 41st aspect according to any one of the preceding aspects, the extensible handrail (5a) has an arched end section (11) which, at least in the second operative condition of the extensible handrail (5a), is placed above the first fixed handrail (2a).
In a 42nd aspect according to any one of the preceding aspects, the auxiliary extensible handrail (5b) has an arched end section (11) which, at least in the second operative condition of the auxiliary extensible handrail (5b), is placed above the second fixed handrail (2b).
In a 43rd aspect according to any one of the preceding aspects, the extensible handrail (5a), in the respective first operative condition, is movable parallel to the first fixed handrail (2a) between a lowered position, in which the extensible handrail (5a) is entirely or substantially entirely disposed adjacent to the first fixed handrail (2a), and an extended position in which at least a part, optionally at least 1/4 or at least 1/3 long of the longitudinal extension of the extensible handrail (5a), extends above the first fixed handrail.
In a 44th aspect according to any one of the preceding aspects, the auxiliary extensible handrail (5b), in the respective first operative condition, is movable parallel to the second fixed handrail (2b) between a lowered position, in which the auxiliary extensible handrail (5b) is entirely or substantially entirely disposed adjacent to the second fixed handrail (2b), and an extended position in which at least a part, optionally at least 1/4 or at least 1/3 of the longitudinal extension of the extensible handrail (5a), extends beyond above the second fixed handrail.
In a 45th aspect according to any one of the two preceding aspects, the extensible handrail (5a) in the extended position is displaceable from the first to the second operative condition to prevent the descent thereof towards the lowered position.
In a 46th aspect according to any one of the three preceding aspects, the auxiliary extensible handrail (5b) in the extended position is displaceable from the first to the second operative condition to prevent the descent thereof towards the lowered position.
In a 47th aspect according to any one of the preceding aspects, the ladder comprises at least a first guide (12a), optionally shaped as an elongated protuberance, emerging radially away from an external surface of the elongated body (3) of the first fixed handrail (2a).
In a 48th aspect according to the preceding aspect, the first guide, at least in the first operative condition of the extensible handrail (5a), is configured to interfere with the extensible handrail (5a) and prevent rotation of the extensible handrail around the elongated body (3) of the first fixed handrail (2a). In a 49th aspect according to any one of the two preceding aspects, the ladder comprises at least a second guide (12b), optionally shaped like a protuberance, emerging radially away from an external surface of the elongated body (3) of the second fixed handrail (2b).
In a 50th aspect according to the preceding aspect, the second guide, at least in the first operative condition of the auxiliary extensible handrail (5b), is configured to interfere with the auxiliary extensible handrail (5b) and prevent rotation of the auxiliary extensible handrail around the elongated body (3) of the second fixed handrail (2b).
In a 51st aspect according to any one of the preceding aspects from the 47th to 50th, the first guide (12a), at least in the first operative condition of the extensible handrail (5a), is configured to cross the intermediate space (8) of the first constraint element (6a) and prevent rotation of the extensible handrail (5a) around the elongated body (3) of the first fixed handrail (2a).
In a 52nd aspect according to any one of the preceding aspects from the 49th to 51st, the second guide (12b), at least in the first operative condition of the auxiliary extensible handrail (5b), is configured to cross the intermediate space (8) of the second constraint element (6b) and prevent rotation of the auxiliary extensible handrail (5b) around the elongated body (3) of the second fixed handrail (2b).
In a 53tf aspect according to any one of the preceding aspects, the first and second guides (12a, 12b) extend along a direction parallel to an axis (X) in interposition between two successive rungs (4).
In a 54th aspect according to any one of the preceding aspects from the 47th to 53rd, the first guide (12a) has, in cross section, a maximum overall dimensions smaller than the minimum distance between the first and the second arm (7a, 7b) of the first constraint element (6a), so that the first constraint element can slide along the first guide while the rotation thereof is prevented.
In a 51st aspect according to any one of the preceding aspects from the 47th to 50th, the second guide (12b) has, in cross section, a maximum overall dimensions smaller than the minimum distance between the first and the second arm (7a, 7b) of the second constraint element (6b), so that the second constraint element can slide along the second guide while the rotation thereof is prevented. In a 56th aspect according to any one of the preceding aspects from the 47th to 55th, the first guide (12a) is spaced from an upper surface of the predetermined rung (4), optionally extending starting from an upper surface of the predetermined rung (4), said distance of the first guide (12a) being measured parallel to the axis (X) and greater than an encumbrance of the first constraint element (6a) also measured along the axis (X).
In a 57th aspect according to any one of the preceding aspects from the 47th to 56th, the first guide (12a), in cooperation with the upper surface of the rung (4), defines a passage configured to allow, during the transition between the first and the second operative condition of the extensible handrail (5a), the rotation of the extensible handrail (5a) around the elongated body (3) of the first fixed handrail (2a).
In a 58th aspect according to any one of the preceding aspects from the 48th to 57th, the second guide (12b) is spaced from an upper surface of the predetermined rung (4), optionally extending starting from an upper surface of the predetermined rung (4), said distance of the second guide (12b) being measured parallel to the axis (X) and greater than an encumbrance of the second constraint element (6b) also measured along the axis (X).
In a 59th aspect according to any one of the preceding aspects from the 48th to the 58th; the distance of the second guide (12b) defines a passage configured to allow, during the transition between the first and second operative conditions of the auxiliary extensible handrail (5b), the rotation of the auxiliary extensible handrail (5b) around the elongated body (3) of the second fixed handrail (2b).
In a 60th aspect according to any one of the preceding aspects, each first and second fixed handrail (2a, 2b) has an upper portion (13) extending transversely to the elongated body starting from the upper end (3b) and being arranged for fixing the ladder to a wall, said upper portion (13) having a predetermined length optionally comprised between 0.5m and 0.2m.
In a 61st aspect, a boat (50) is provided, comprising:

at least one well (51) for access to an under-deck environment of the boat, said well (51) being delimited by a side wall (14) defining a passage opening (52) for a user,
a ladder (1) according to any one of the preceding aspects engaged to the side wall (14) of the well (51).

In a 62nd aspect according to the preceding aspect, in the first operative condition, the extensible handrail (5a) is positionable in its extended position in which it is arranged at least partially outside the well (51) passing through the passage opening (52 ).
In a 62nd aspect according to any one of the two preceding aspects, when the extensible handrail (5a) is in its extended position, a part at least 1/4 or at least 1/3 long of the longitudinal extension of the extensible handrail (5a), extends above the access opening (52).
In a 63rd aspect according to any one of the three preceding aspects, the extensible handrail (5a), in the extended position, is displaceable from the first to the second operative condition so as to prevent the descent of the same extensible handrail towards the lowered position thereof, in which the extensible handrail does not protrude or slightly protrudes from the passage opening (52) and is arranged inside the well (51).
In a 64th aspect according to any one of the preceding aspects from the 61st to the 63rd, in the first operative condition, the auxiliary extensible handrail (5b) is positionable in its extended position in which it is arranged at least partially outside the well (51) passing through the passage opening (52 ).
In a 65th aspect according to any one of the preceding aspects, when the auxiliary extensible handrail (5b) is in its extended position, a part at least 1/4 or at least 1/3 long of the longitudinal extension of the auxiliary extensible handrail (5b), extends above the access opening (52).
In a 66th aspect according to any one of the preceding aspects, the auxiliary extensible handrail (5b), in the extended position, is displaceable from the first to the second operative condition so as to prevent the descent of the same auxiliary extensible handrail towards the lowered position thereof, in which the auxiliary extensible handrail does not protrude or slightly protrudes from the passage opening (52) and is arranged inside the well (51).
In a 67th aspect according to any one of the preceding aspects, each of said first and second fixed handrail (2a, 2b) has an upper section (13) extending transversely to the elongated body starting from the upper end (3b), said upper section constraining each of said first and second fixed handrail (2a, 2b) to the side wall (14) of the well (51).
In a 68th aspect according to any one of the preceding aspects, the/a under-deck area of the boat has a base plane (16), and wherein each of said first and second fixed handrail (2a, 2b) is engaged to the base plane (16) at the lower end (3a) of the respective elongated body (3).
In a 69th aspect according to any one of the preceding aspects from the 61st to the 68th, the boat (50) comprises a closing door (53) of the well, and wherein, with the extensible handrail and the auxiliary extensible handrail (5a, 5b) in the lowered positions thereof, the closing door can be positioned in a position for closing, optionally in liquid-tight manner, of the access opening (52).
In a 70th aspect, a boat (50) is provided, comprising:

at least one hull (54) delimited by a perimeter edge (55),
a ladder (1) according to any one of the preceding aspects from the 1st to the 60th, engaged to the hull at the perimeter edge (55) to allow boarding the boat.

In a 71st aspect according to the preceding aspect, at least during a stationary condition of the boat (50), the extensible handrail and/or the auxiliary extensible handrail are arranged at least partially above the perimeter edge (55).
In a 72nd aspect according to the preceding aspect, when the extensible handrail (5a) and/or the auxiliary extensible handrail (5b) are in the extended position thereof, a part at least 1/4 or at least 1/3 long of the respective longitudinal extension extends above the perimeter edge (55).
In a 73rd aspect according to any one of the three preceding aspects, the boat comprises at least one safety bulkhead (57) engaged to the hull (54) at the perimeter edge (55), wherein the ladder (1) is engaged to said safety bulkhead (57).
In a 74th aspect according to the preceding aspect, the extensible handrail and/or the auxiliary extensible handrail, at least during the stationary condition of the boat (50), are arranged at least partially above the safety bulkhead (57) .
In a 75th aspect according to any one of the preceding aspects from the 70th to the 74th, the boat comprises at least one platform (56) defined at the perimeter edge (55) of the boat, wherein the ladder (1) is engaged to said platform (56).
In a 76th aspect according to the preceding aspect, the extensible handrail and/or the auxiliary extensible handrail, at least during the stationary condition of the boat (50), are arranged at least partially above the platform (56).
In a 77th aspect according to any one of the aspects from the 2nd to the 69th, the extensible handrail (5a) is movable along the first fixed handrail (2a) independently of the mobility of the auxiliary extensible handrail (5b) along the second fixed handrail (2b).
In a 78th aspect according to the preceding aspect, the ladder provides that there is no rigid mechanical connection between the extensible handrail (5a) and the auxiliary extensible handrail (5b) which requires the two handrails to be movable in a synchronous manner along the first and second fixed handrails, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments and some aspects of the invention are described hereinafter with reference to the accompanying drawings, provided only for illustrative and, therefore, non-limiting purposes, in which:

Figures 1A and 1B are perspective views of a ladder according to the present invention, in a first and a second operative condition of the extensible handrails, respectively;
Figure 2 is a cross-sectional view according to the plane II-II of Figure 1A of the ladder according to the present invention during the first operative condition, in which the removable handrails are in a lowered position and entirely or almost entirely arranged adjacent to the fixed handrails of the ladder itself;
Figures 3 and 4 are perspective views of a detail of the ladder in the condition of Figure 1A and in the condition of Figure 1B, respectively;
Figure 5 is a perspective view showing a possible variant according to a further embodiment of the ladder according to the present invention;
Figure 6 is a cross-sectional view according to plane VI-VI of Figure 5;
Figure 7 is a perspective view of a boat according to the present invention showing the ladder of Figure 1 installed at an under-deck access well of the boat itself,
Figures 8 and 9 are perspective views of a boat according to the present invention showing the ladder of Figure 1 installed at a perimeter edge delimiting a hull of the boat itself.

DETAILED DESCRIPTION

The invention relates to a ladder 1 for boat wells and a boat 50 having the ladder 1 operating at the or at each well. With reference to Figure 7, a boat 50 is illustrated having at least one well 51 for accessing an area below deck of the boat. A ladder 1 operates at each well 50 which allows the on-board personnel to descend towards the area below deck or to go up from the area below the deck, for example to reach a deck of the boat 50.
The well 51 is delimited at the top by a passage opening 52 defined on the deck of the boat, through which the on-board personnel have access to the area below deck. The well 51 can be peripherally delimited by at least one side wall 14, which delimits the opening 52 and allows the fixing of a portion of the ladder. Figures 1A and 1B schematically illustrate the well area and the access below deck, which has a base plane 16 delimiting the well 51 below and configured to allow the fixing of a further portion of the ladder. Of course, the ladder can alternatively be fixed only to the side wall 14. The boat 50 can further comprise a closing door 53 of the well 51 movable, for example rotationally movable, with respect to the passage opening 52 of the well 51 and configured to selectively allow and prevent access to the well 51.
It should be further noted, as shown in Figures 8 and 9, that the boat 50 has a hull 54 delimited by a perimeter edge 55: at the perimeter edge, the ladder 1 can operate to allow a user access on board the boat 50.
In particular, Figure 8 shows a boat 50 comprising a safety bulkhead 57 engaged to the hull at the perimeter edge 55. In this configuration, the ladder 1 can be engaged with the safety bulkhead 57 to allow access on board the boat, for example from one side of the latter.
Figure 9 instead shows a stern area of the boat, the latter comprising a platform 56 engaged to the hull at the perimeter edge. In this configuration of the boat 50, the ladder 1 can be engaged to the platform 56, allowing a user to board the boat.
It should be noted that during a stationary condition of the boat, the ladder 1 is at least partially arranged above the safety bulkhead 57 and/or the platform 56 to facilitate the boarding of a user.
As shown for example in Figures 1A and 1B, the ladder comprises a first and a second fixed handrail 2a, 2b fixed to the well and configured to facilitate gripping of the ladder. In particular, each fixed handrail has a respective elongated body 3 extending between a lower end and an upper end 3a, 3b along substantially rectilinear and mutually parallel directions. The first and second fixed handrails 2a, 2b further have an upper section 13 extending transversely to the elongated body starting from the upper end 3b, designed to fix the ladder to the side wall 14 of the well 51. Each upper section 13 extends in interposition between the elongated body 3 and the side wall 14 of the well to which the handrail is fixed. In fact, it should be noted that the upper section 13 has a reduced length, for example between 0.5m and 0.2m, to allow the construction of a ladder capable of minimizing the overall dimensions and facilitating the transit of a user of the ladder through the well. The first and second fixed handrails 2a, 2b can be further constrained to the base plane 16 of the well 51 or to the lower wall of the wall 14, at the lower end 3a of the respective elongated body 3.
The ladder further comprises a predetermined number of rungs 4 transversely engaged with the elongated body 3 of the first and second fixed handrails 2a, 2b: the rungs 4 are parallel to each other and spaced along the extension direction of each fixed handrail and configured to support a user of the ladder and allow the transit thereof. Each rung 4 preferably has a predetermined transverse bulk adapted to allow comfortable and safe rest and support for the user during ascent or descent.
As shown in the accompanying figures, the ladder has at least one extensible handrail 5: actually, in the currently preferred embodiment the ladder comprises an extensible handrail 5a movable relative to the first fixed handrail 2a and an auxiliary extensible handrail 5b movable relative to the second fixed handrail 2b.
It should be noted that the extensible handrail 5a and the auxiliary extensible handrail 5b are preferably identical to each other and engaged in a similar way to the respective fixed handrails 2a, 2b. Consequently, for ease of discussion, when speaking generically of extensible handrail (or of each extensible handrail), reference is made to the features of both the extensible handrail 5a and of the auxiliary extensible handrail 5b or of the single handrail 5 if a ladder with one handrail only. Further, in the accompanying figures reference is made to an extensible handrail 5a movable independently with respect to the auxiliary extensible handrail 5b: in other words, the extensible handrail 5a is movable along the first fixed handrail 2a independently of the mobility of the auxiliary extensible handrail 5b along the second fixed handrail 2b. In practice, each extensible handrail is constrained to the respective one of said first and second fixed handrails, but there is no rigid mechanical connection between the extensible handrail 5a and the auxiliary extensible handrail 5b which requires the two handrails to be movable in a synchronous manner respectively along the first and second fixed handrails, that is, which forces the two extensible handrails to go up and down together.
Although the described solution is currently the preferred and most advantageous one, it is not excluded, however, that in an embodiment of the present invention, the extensible handrail 5a and the auxiliary extensible handrail 5b are synchronously movable. For example, the extensible handrail 5a and the extensible handrail 5b can be mechanically connected to each other (for example with a transverse bar or other mechanical connection) or synchronized in motion through the use of one or more motors or actuators and appropriate transmission components adapted to connect the extensible handrails to each other making their movement synchronous and motorized or servo-assisted.
From the structural point of view, each extensible handrail 5, 5a, 5b is engaged to the elongated body 3 of the fixed handrail 2a or 2b and extends along an axis X parallel and adjacent to the elongated body 3 of the fixed handrail 2a or 2b. The extensible handrail 5, 5a, 5b can also be positioned relative to the fixed handrail 2a, 2b between a first and a second operative position. In the first operative position, the extensible handrail 5, 5a, 5b is movable along at least a portion of the elongated body of the respective fixed handrail 2a or 2b, while, in the second operative position, the extensible handrail interferes with at least one rung 4, to limit or prevent the mobility of the extensible handrail 5, 5a, 5b along the same elongated body 3 of the respective fixed handrail.
In the first operative condition, the extensible handrail 5, 5a, 5b can also be moved parallel to the fixed handrail 2a, 2b between a lowered position and an extended position. In the lowered position, each extensible handrail 5, 5a, 5b is at least partially arranged adjacent to the respective fixed handrail 2a, 2b inside the well 51, while, in the extended position, at least a portion of the extensible handrail 5, 5a, 5b is placed outside the well 51, in such a way as to allow a user to grip the extensible handrail, for example placed on the deck of the boat. In the embodiment of the invention shown in Figures 8 and 9, at least a portion of the extensible handrail 5, 5a, 5b is placed above the safety bulkhead 56 or above the platform 57, to allow gripping of the extensible handrail by a user, for example placed on the deck of the boat or on the platform itself, and facilitate the descent thereof. In particular, as shown in the accompanying figures, at least a portion of the extensible handrail, optionally having a length equal to at least one quarter of the total length of the extensible handrail itself, is located outside the well 51. It should be further noted that the accompanying figures show the extensible handrails 5, 5a, 5b manually movable between the lowered position and the extended position. However, as already mentioned, the possibility of motorized or servo-assisted movement to move the/each extensible handrail between the respective lowered position and the respective extended position is not excluded. Each extensible handrail 5, 5a, 5b can also have an arched end section 22 which, at least in the second operative condition of the extensible handrail, is placed above the respective fixed handrail 2a, 2b: such end section can extend at least partially externally to the well 51, to facilitate the grip of the extensible handrail by a user and to facilitate the grip thereof and/or assist the descent thereof towards the space below deck.
As shown in Figures 1A, 1B and 2, the ladder can have at least a first and second constraint element 6a, 6b respectively integral with the extensible handrail 5a and the auxiliary extensible handrail 5b and configured to engage with the elongated body 3 of a respective first and second fixed handrail 2a, 2b. Of course, in the case of a ladder with a single extensible handrail 5, there will be a constraint element 6 associated with such single extensible handrail. Each constraint element 6, 6a, 6b is slidingly engaged to the elongated body 3 of the respective fixed handrail 2a, 2b in interposition between the same fixed handrail and the extensible handrail 5, 5a, 5b to allow the movement of the extensible handrail itself between the first and the second operative condition and the displacement of the extensible handrail 5, 5a, 5b between the lowered position and the extended position.
Each extensible handrail 5, 5a, 5b can comprise two or more respective constraint elements 6 defined at distinct portions of each extensible handrail 5, 5a, 5b, so as to support the extensible handrail itself and position it parallel to the fixed handrail 2a, 2b. Each constraint element 6, 6a, 6b is slidingly engaged to the elongated body 3 of the respective first or second fixed handrail 2a, 2b to allow movement of the extensible handrail 5, 5a, 5b relative to the fixed handrail.
As shown in Figure 2, each constraint element 6, 6a, 6b comprises a main body 7 engaged transversely to the respective extensible handrail 5, 5a, 5b and configured to interfere with a rung during the second operative condition of the extensible handrail, preventing the descent of the extensible handrail itself from the extended position to the lowered position. Each constraint element 6, 6a, 6b further comprises a first and a second arm 7a, 7b distinct and spaced apart and extending in extension starting from the main body 7. The first and the second arm 7a, 7b of each constraint element extend along respective curvilinear trajectories having mutually facing concavities. In other words, the first and second arms 7a, 7b, in cooperation with the main body 7, define a convex shape having, in cross section, a substantially "C" or "U" shape. The first and second arms 7a, 7b are in fact spaced apart, defining an intermediate space 8 in interposition between respective ends opposite to the main body 7.
The first and the second arm 7a, 7b of each constraint element 6 further define a seat 20 configured to at least partially house the elongated body 3 of the respective fixed handrail. From the structural profile, the seat 20 of each constraint element 6, 6a, 6b has, in cross-section, a predominant portion of the profile thereof complementarily shaped with respect to a perimeter profile of the cross-section of the elongated body 3 of the fixed handrail 2. This conformation of the seat 20 allows the extensible handrail 5, 5a, 5b to be guided along the elongated body 3 of the respective fixed handrail 2a, 2b, between the first and second operative conditions and vice versa. The conformation of the seat 20 of each constraint element 6, 6a, 6b also prevents the extraction of the extensible handrail 5, 5a, 5b from the fixed handrail 2, allowing the translation of the same extensible handrail along the elongated body 3 of the respective fixed handrail, as well as the rotation of the extensible handrail 5, 5a, 5b around the elongated body 3. To prevent the extraction of the constraint element 6, 6a, 6b from the elongated body of the respective fixed handrail 2a, 2b, the opposite ends of the first and second arms 7a, 7b are placed at a minimum distance smaller than an overall minimum dimension of the cross section of the elongated body of the fixed handrail 2a, 2b. For example, the elongated body 3 of the fixed handrail 2a, 2b can have, in cross section, a circular profile with a larger diameter than the minimum distance between the first and second arms 7a, 7b. Furthermore, the main body 7 of the constraint element 6, 6a, 6c defines, in cooperation with the first and second arms 7a, 7b, a single rigid body, which cannot be elastically deformed without the aid of hydraulic/pneumatic tools or members, so as to prevent the undesired decoupling of the constraint element from the respective fixed handrail.
It should be further noted how the opposite ends of the first and second arms 7a, 7b of each constraint element 6, 6a, 6b are placed at a minimum distance greater than a maximum overall dimension of the cross section of each rung 4. In other words, the minimum distance between the first and second arm 7a, 7b of each constraint element is sufficiently high to allow, during the movement of the extensible handrail 5, 5a, 5b between the lowered position and the extended position, the passage of a rung 4 through the intermediate space 8, preventing mechanical interference between the rung 4 itself and the constraint element 6, 6a, 6b.
In an embodiment of the present invention, each extensible handrail 5, 5a, 5b has at least one respective stop element 9 configured to interfere, at least in the second operative condition of the extensible handrail 5, 5a, 5b, with a rung 4 and at least partly prevent the rotation of the extensible handrail 5, 5a, 5b around the elongated body 3 of the fixed handrail 2. As shown in Figures 3 and 4, the stop element 9 of each extensible handrail 5, 5a, 5b comprises at least one relief emerging transversely from at least one or each constraint element 6, 6a, 6b associated with the extensible handrail itself (in other words if an extensible handrail carries more than one constraint element, at least one of these constraint elements is provided with the stop element 9 in the form of a relief). The stop element or relief 9 is configured to allow the arrangement of at least one rung 4, in interposition between the stop element 9 and the extensible handrail 5. In this configuration, the stop element 9 interferes with the rung 4, preventing at least in part the rotation of the extensible handrail 5, 5a, 5b around the elongated body 3 of the fixed handrail 2a, 2b. The extensible handrail 5, 5a, 5b can comprise a first and a second stop element 9a, 9b, distinct from each other (preferably carried by the same constraint element 6, 6a, 6b) and spaced apart to define a seat 10 which, at least in the second operative condition of the extensible handrail 5, is configured to receive a rung 4 inserted thereinto. The first and second stop elements 9a, 9b are for example carried by one or more constraint elements 6, 6a, 6b and placed at a minimum distance greater than the maximum overall dimension of the cross section of each rung 4, to allow insertion and extraction of a rung 4 from the seat 10, simply by slightly raising and lowering the extensible handrail on which one is working. The rung 4, inserted within the seat 10, is interposed between the first and the second stop element 9a, 9b and prevents the rotation of the extensible handrail 5, 5a, 5b around the elongated body 3 of the fixed handrail 2a, 2b. The displacement of the extensible handrail 5, 5a, 5b from the second to the first operative condition, takes place after moving the extensible handrail 5, 5a, 5b transversely to the rungs (in particular upwards) to determine the disengagement of the rung 4 from the seat 10 of the constraint element 6, 6a, 6b. In other words, the extraction of the rung 4 from the seat 10 of the stop element 9 takes place by lifting the extensible handrail 5, 5a, 5b, while the displacement of the extensible handrail from the second to the first operative condition occurs by subsequent rotation of the extensible handrail 5 substantially around the fixed handrail 2a, 2b.
In an embodiment variant illustrated in Figure 5 and Figure 6, the ladder can further comprise a first and a second guide 12a, 12b (or a single guide 12 on one or the other of the fixed handrails 2a, 2b if the ladder includes only one extensible handrail 5). Each guide 12, 12a, 12b emerges radially away from an external surface of the elongated body 3 of a respective fixed handrail 2a, 2b. The first and second guides 12a, 12b of the example of Figure 6 are substantially identical to each other: in any case each guide 12, 12a, 12b is configured, during the first operative condition of the respective extensible handrail, to interfere with an extensible handrail 5, 5a, 5b and prevent the rotation thereof around a respective fixed handrail.
In particular, as shown for example in Figures 5, 6, each guide 12, 12a, 12b extends along a direction parallel to the axis X in interposition between two successive rungs 4. During the displacement of the extensible handrail along the elongated body 3 of the respective fixed handrail 2a, 2b, the guide 12, 12a, 12b is arranged inside the intermediate space 8 of the constraint element, preventing undesired rotation of the extensible handrail around the fixed handrail and facilitating the sliding and at least partial extraction of the extensible handrail outside the well 51. In fact, the guide 12, 12a, 12b rotationally constrains the extensible handrail 5, 5a, 5b during the translation of the latter along the elongated body 3 of the fixed handrail 2. The guide 12, 12a, 12b has, in cross section, a maximum overall dimensions smaller than the minimum distance between the first and the second arm 7a, 7b of the constraint element 6, 6a, 6b so that the constraint element can slide along the respective guide 12, 12a, 12b. It should also be noted that the guide 12, 12a, 12b can be spaced at the bottom from an upper surface of a rung 4 to allow the rotation of the respective extensible handrail around the associated fixed handrail and thus allow the achievement of the second operative condition. In particular, each guide 12, 12a, 12b is spaced from the upper surface of the rung 4 by an amount measured parallel to the axis X greater than an overall size (in thickness) of the constraint element 6 always measured along the axis X. Each guide 12, 12a, 12b in cooperation with the upper surface of the rung 4 defines a passage configured to allow, during the transition between the first and second operative conditions of the extensible handrail 5, 5a, 5b, the rotation of the extensible handrail itself around to the elongated body 3 of the respective fixed handrail 2a, 2b.
In use, the ladder is entirely fixed inside the well 51, constrained at the top to the side wall 14 of the well at the end sections 13 of each fixed handrail and below it fixed to the base surface 16 or to the side wall of the well 51 at the first end 3a of each fixed handrail 2.
To reach the space below the deck of the boat, a user located on the deck lifts the closing door 53 of the well (if present) to access the ladder 1 entirely located in the area below deck. The user verifies that each extensible handrail is in the first operative condition and subsequently moves, independently or simultaneously, the extensible handrail(s) 5, 5a, 5b from the lowered position to the extended position. During such displacement, at least the end section 11, for example arched, of each extensible handrail emerges from the well 51. In particular, at least a portion of the elongated body 3 of each extensible handrail 5 emerges from the well 51, in such a way as to distance each end section 11 from the deck of the boat and allow the user to grip each end section 11 without bending down. Following the displacement of the one or more extensible handrails 5, 5a, 5b in the extended position, the user rotates, independently or simultaneously, each extensible handrail around the respective fixed handrail, reaching the second operative condition. Following such displacement, each constraint element 6, 6a, 6b is arranged in abutment against a rung 4, preventing the descent of an extensible handrail 5, 5a, 5b in the retracted position. The user can thus firmly cling to the extensible handrail(s) 5, 5a, 5b before going down or during the descent into the area below deck of the boat.
In the embodiment of the invention in which each constraint element 6, 6a, 6b has respective first and second stop elements 9a, 9b, the user reaches the second operative condition of each extensible handrail 5, 5a, 5b by engaging a rung 4 in insertion inside the seat 10, by rotating the extensible handrail itself.
Vice versa, the displacement of the extensible handrail 5, 5a, 5b from the first to the second operative condition and subsequently to the retracted position, occurs as a result of:

disengagement of each constraint element 6, 6a, 6b from a rung 4 to which the constraint element is engaged, in particular by lifting the extensible handrail or both extensible handrails so that the rung 4 comes out of the seat 10 or in any case cannot more interfere with the stop element 9a and/or 9b,
rotation of the extensible handrail 5, 5a, 5b to the first operative position,
displacement of the extensible handrail 5, 5a, 5b to the retracted position.

As mentioned above, the displacement of each extensible handrail 5, 5a, 5b can be done manually; however, the provision of a motorized system for the automatic movement of each extensible handrail from the retracted position to the extended position and from the first to the second operative condition and vice versa is not excluded.

Claims

Ladder comprising:
- a first and a second fixed handrail (2a, 2b) each of which has an elongated body (3) extending between a lower end and an upper end (3a, 3b),

- a pre-set number of rungs (4) transversely engaged to the first and to the second fixed handrail (2a, 2b),

- at least one extensible handrail (5a) engaged to the elongated body (3) of the first fixed handrail (2a),
characterized in that the extensible handrail (5a) is configured to be positioned relative to the first fixed handrail (2a) at least between:
- a first operative condition in which the extensible handrail (5a) is movable along at least one portion of the elongated body (3) of the first fixed handrail (2a), and

- a second operative condition in which the extensible handrail (5a) is configured to interfere with at least one rung (4) which limits or hinders the mobility thereof along the elongated body (3) of the first fixed handrail (2a).
Ladder according to the preceding claim comprising an auxiliary extensible handrail (5b) engaged to the elongated body (3) of the second fixed handrail (2b), wherein the auxiliary extensible handrail (5b) is configured to be positioned relative to the second fixed handrail (2b) at least between:
- a first operative condition in which the auxiliary extensible handrail (5b) is movable along at least one portion of the elongated body (3) of the second fixed handrail (2b),

- a second operative condition in which the auxiliary extensible handrail (5b) is configured to interfere with at least one rung (4) which limits or hinders the mobility thereof along the elongated body (3) of the second fixed handrail (2b).
Ladder according to the preceding claim, wherein the extensible handrail (5a) is movable independently of the auxiliary extensible handrail (5b), particularly wherein there is no rigid mechanical connection between the extensible handrail (5a) and the auxiliary extensible handrail (5b) that compels the two handrails to be synchronously movable.
Ladder according to the claim 2 or 3, wherein:
- the extensible handrail (5a) has at least one first constraint element (6a) slidably engaged to the elongated body (3) of the first fixed handrail (2a),

- the auxiliary extensible handrail (5b) has at least one second constraint element (6b) slidably engaged with the elongated body (3) of the second fixed handrail (2b),
or wherein:
- the extensible handrail (5a) comprises two or more first constraint elements (6a) slidably engaged at distinct portions of the elongated body (3) of the first fixed handrail (2a), and

- the auxiliary extensible handrail (5b) comprises two or more second constraint elements (6b) slidably engaged at distinct portions of the elongated body (3) of the second fixed handrail (2b).
Ladder according to the preceding claim, wherein each of said first and second constraint element (6a, 6b) has:
- a main body (7) transversely engaged to the extensible handrail (5a) or with the auxiliary extensible handrail (5b),

- a first and a second arm (7a, 7b) projecting as an extension of the main body, distinct and spaced from each other; and in which an intermediate space (8) is defined between respective ends of the first and of the second arm (7a, 7b) opposite the main body (7),

wherein the first and the second arm (7a, 7b) of the first constraint element (6a) define a seat (20) configured to at least partially house the elongated body (3) of the first fixed handrail (2a),

and wherein the first and the second arm (7a, 7b) of the second constraint element (6b) define a seat (20) configured to at least partially house the elongated body (3) of the second fixed handrail (2b); optionally wherein, in cross-section, the main body (7) of the constraint element (6) defines, in cooperation with said first and second arm (7a, 7b), a convex shape, for example substantially C or U-shaped,

more optionally wherein the first and the second arm (7a, 7b) of each constraint element extend along respective curvilinear trajectories having mutually facing concavities.
Ladder according to the preceding claim, wherein the seat (20) of the first constraint element (6a) has, in cross-section, a predominant portion of the profile thereof complementarily shaped with respect to a perimeter profile of the cross-section of the elongated body (3) of the first fixed handrail (2a),
and wherein the seat (20) of the second constraint element (6b) has, in cross-section, a predominant portion of the profile thereof complementarily shaped with respect to a perimeter profile of the cross-section of the elongated body (3) of the second fixed handrail (2b).
Ladder according to any one of the two preceding claims, wherein the main body (7) of a respective first and second constraint element (6a, 6b) defines, in cooperation with the first and the second arm (7a, 7b), a single rigid body,
wherein the intermediate space (8) of the first constraint element (6a) is configured to prevent the removal of the elongated body (3) of the first fixed handrail (2a) from the seat (20),

and wherein the intermediate space (8) of the second constraint element (6b) is configured to prevent the removal of the elongated body (3) of the second fixed handrail (2b) from the seat (20).
Ladder according to any one of the three preceding claims, wherein the opposite ends of the first and second arm (7a, 7b) of the first constraint element (6a) are arranged at a minimum distance smaller than the minimum overall dimension of the cross-section of the elongated body of the first fixed handrail (2a),
and wherein the opposite ends of the first and second arm (7a, 7b) of the second constraint element (6b) are arranged at a minimum distance smaller than the minimum overall dimension of the cross-section of the elongated body of the second fixed handrail (2b),

optionally, wherein the elongated body (3) of the first and of the second fixed handrails (2a, 2b) has a circular-shaped cross-section with a diameter larger than the minimum distance between the first and the second arm (7a, 7b) of the first and of the second constraint element,

and wherein the opposite ends of said first and second arm (7a, 7b) of the first and of the second constraint element (6a, 6b) are arranged at a minimum distance greater than a maximum overall dimension of the cross-section of each rung (4).
Ladder according to any one of the preceding claims 5 to 8, wherein the intermediate space (8) of the first constraint element (6a), in the first operative condition of the extensible handrail (5a), is configured to receive the rungs (4) passing through,
said intermediate space (8) of the second constraint element (6b), in the first operative condition of the auxiliary extensible handrail (5b), being configured to receive the rungs (4) passing through.
Ladder according to any one of the preceding claims, wherein the extensible handrail (5a), at least during the transition between the first and second operative condition, is rotatably movable around the elongated body (3) of the first fixed handrail (2a), and/or
wherein the auxiliary extensible handrail (5b), at least during the transition between the first and the second operative condition, is rotatably movable around the elongated body (3) of the second fixed handrail (2b).
Ladder according to any one of the preceding claims from 5 to 10, wherein the extensible handrail (5a), at least during the transition between the first and second operative condition, is rotatably movable around the elongated body (3) of the first fixed handrail (2a), and wherein the first constraint element (6a), in the second operative condition of the extensible handrail (5a), is arranged in contact with, optionally above, a rung (4),
wherein the auxiliary extensible handrail (5b), at least during the transition between the first and the second operative condition, is rotatably movable around the elongated body (3) of the second fixed handrail (2b) and wherein the second constraint element (6b), in the second operative condition of the auxiliary extensible handrail (5b), is arranged in contact with, optionally above, a rung (4).
Ladder according to any one of the preceding claims from 4 to 11, wherein the extensible handrail (5a) has at least one respective stop element (9) configured to interfere, at least in the second operative condition of the extensible handrail (5a), with a rung (4) and at least partly prevent the rotation of the extensible handrail (5a) around the elongated body (3) of the first fixed handrail (2a), and wherein the auxiliary extensible handrail (5b) has at least one respective stop element (9) configured to interfere, at least in the second operative condition of the auxiliary extensible handrail (5b), with a rung (4) and at least partly prevent the rotation of the auxiliary extensible handrail (5b) around the elongated body (3) of the second fixed handrail (2b),
wherein each stop element (9) of the extensible handrail (5a) comprises at least one relief, optionally a pin, projecting transversely from the first constraint element (6a), optionally projecting transversely from at least one of said first and second arm (7a, 7b),

and wherein each stop element (9) of the auxiliary extensible handrail (5b) comprises at least one relief, optionally a pin, transversely projecting from the second constraint element (6b), optionally transversely projecting from at least one of said first and second arm (7a, 7b).
Ladder according to the preceding claim, wherein at least one rung (4), in the second operative condition of the extensible handrail (5a), is interposed between the stop element (9) of the first constraint element (6a) and the extensible handrail (5a),
wherein at least one rung (4), in the second operative condition of the auxiliary extensible handrail (5b), is interposed between the stop element (9) of the second constraint element (6b) and the auxiliary extensible handrail (5b),

said stop element (9) of the first constraint element (6a) comprising a first and a second stop element (9a, 9b) distinct and spaced from each other, said first and second stop element (9a, 9b) defining a seat (10) which, at least in the second operative condition of the extensible handrail (5a), is configured to receive a rung (4) inserted thereinto,

wherein the stop element (9) of the second constraint element (6b) comprises a first and a second stop element (9a, 9b) distinct and spaced from each other, said first and second stop element (9a, 9b) defining a seat (10) which, at least in the second operative condition of the auxiliary extensible handrail (5b), is configured to receive a rung (4) inserted thereinto,

optionally the first and the second stop element (9a, 9b) of each of said first and second constraint element (6a, 6b) are arranged at a minimum distance greater than a maximum overall dimension of the cross-section of each rung (4).
Ladder according to the preceding claim, wherein the first constraint element (6a) is configured so that the displacement of the extensible handrail (5a) from the second to the first operative condition occurs after the displacement of the extensible handrail (5a) transversely to said rungs, in particular parallel to the first fixed handrail, so as to disengage the rung (4) from the seat (10) of the first constrai nt element (6a),
and wherein the second constraint element (6b) is configured so that the displacement of the auxiliary extensible handrail (5b) from the second to the first operative condition occurs after the displacement of the auxiliary extensible handrail (5b) transversely to said rungs, in particular parallel to the second fixed handrail, so as to disengage the rung (4) from the seat (10) of the second constraint element (6b).
Boat (50) comprising:
- at least one hull (54) delimited by a perimeter edge (55),

- a ladder (1) according to any one of the claims engaged to the hull at the perimeter edge (55) to allow to board the boat;
and/or

- at least one well (51) for access to an under-deck environment of the boat, said well (51) being delimited by a side wall (14) defining a passage opening (52) for a user,

- a ladder (1) according to any one of the preceding claims engaged to the side wall (14) of the well (51);
in particular wherein:
- in the first operative condition, the extensible handrail (5a) is positionable in the extended position thereof in which it is arranged at least partially outside the well (51) passing through the passage opening (52), optionally wherein when the extensible handrail (5a) is in the extended position thereof, a part at least 1/4 or at least 1/3 long of the longitudinal extension of the extensible handrail (5a) extends above the access opening (52); and wherein said extensible handrail (5a), in the extended position, is displaceable from the first to the second operative condition so as to prevent the descent of the extensible handrail toward the lowered position thereof, wherein the extensible handrail does not protrude or slightly protrudes from the passage opening (52) and it is arranged inside the well (51),

- in the first operative condition, the auxiliary extensible handrail (5b) is positionable in the extended position thereof in which it is arranged at least partially outside the well (51) passing through the passage opening (52), optionally wherein when the auxiliary extensible handrail (5b) is in the extended position thereof, a part at least 1/4 or at least 1/3 long of the longitudinal extension of the auxiliary extensible handrail (5b) extends above the access opening (52); and wherein said auxiliary extensible handrail (5b), in the extended position, is displaceable from the first to the second operative condition so as to prevent the descent of the auxiliary extensible handrail toward the lowered position thereof, wherein the auxiliary extensible handrail does not protrude or slightly protrudes from the passage opening (52) and it is arranged inside the well (51);
more in particular wherein:
- each of said first and second fixed handrail (2a, 2b) has an upper section (13) of each ladder extending transversely to the elongated body starting from the upper end (3b), said upper section constraining each of said first and second fixed handrail (2a, 2b) to the side wall (14) of the well (51) or to the perimeter edge (55) of the boat,

- the under-deck area of the boat has a base plane (16), and wherein each of said first and second fixed handrail (2a, 2b) of the ladder is engaged to the base plane (16) at the lower end (3a) of the respective elongated body (3),

- optionally, the boat (50) comprises a closing door (53) of the well, and wherein, with the extensible handrail and the auxiliary extensible handrail (5a, 5b) in the lowered positions thereof, the closing door can be positioned in a position for closing, optionally in liquid-tight manner, of the access opening (52).