Patent Publication Number: US-11383795-B2

Title: Craft with device for movement of a stern platform provided with integrated steps

Description:
This claims the benefit of Italian patent application no. 102019000012366, filed Jul. 19, 2019, hereby incorporated by reference in its entirety. 
     FIELD OF THE INVENTION 
     The subject of the present invention is a craft or boat. 
     BACKGROUND OF THE INVENTION 
     For some time boats have been known, such as yachts or the like, with a hull which, in the aft part, have a stern platform or aft defined by a plane which projects orthogonally from the hull, and can act as a “swimming platform” for passengers of the craft. This platform or swimming platform can be fixed or mobile relative to the hull: in this last case, the platform or a portion thereof can move relative to the hull, and can adopt any position at least between a first position of work projecting from the hull and adhering thereto, and a second portion in which the platform is totally immersed in the water on which the boat is located. 
     Craft are also known with an aft opening which for example is used to contain a small boat or tender. This opening is usually closed by its own aft hatch. 
     In the case in which the craft has the aft opening, and in the case in which the platform is secured on the hull, the presence of this swimming platform can be an obstacle to easy access to the aft opening directly from the sea. 
     For this reason, in the case of a hull with an aft opening, it is preferable to produce these platforms provided with at least one mobile part, such that access to and from the sea via this opening can be cleared. 
     Usually, the mobile aft platforms are connected to the hull of the craft by means of guides which are integral with the hull (for example of the telescopic, or fixed and straight type), or by means of articulated on pantograph supports which, when the aft opening is opened, translate the corresponding platform relative to the hull, but with a circular trajectory. One or more movement devices permit the passage of the mobile platform from the first position of work to the second and vice versa. 
     In the case of articulated supports, when the platform is immersed in the water, it may not be easy to go from the platform to the hull of the boat in order to get back up onto the boat or vice versa, because a support with a pantograph with a curved trajectory tends to move the platform (or swimming platform) away from the craft. 
     In the case when use of a tender is planned for example, the immersion of the platform in the water on the one hand facilitates launching of the tender and getting onto this tender by the passengers, but on the other hand it may make it difficult for the passengers themselves to get back up onto the boat, (from which the tender has been put into the water). 
     It is therefore known to associate small step ladders with the mobile platforms in order to facilitate the passage of people from the platform immersed in the water to the hull of the craft. 
     For example, DE 20 2009 007140 U1 describes a craft or boat with a mobile stern platform which can be kept out of the water on which the boat is located, or it can be carried under the surface of the water by means of movement devices with a pantograph with articulated quadrilaterals, hinged on the hull of the boat and rotatable around these hinges. 
     The German prior art describes that a small step ladder is integral with the platform, which ladder is invisible (or “disappears”) when the platform is in the first position of work alongside the hull and out of the water: on the other hand this small step ladder is on view when the platform goes into the second position of work and is immersed in the water. When the platform is completely immersed (i.e. it is in the second position of work), the small step ladder is completely on view and is used to reach the hull of the boat easily and get up onto the hull starting from the platform immersed in the water. 
     According to one embodiment, the small step ladder is hinged at one of its ends on the platform, whereas at the other end it is hinged on the hull. According to another embodiment, the small step ladder is freely supported on the mobile platform, and can slide in a guided manner inside a recess or seat present on said hull. 
     In the known prior solution, the small step ladder is thus an independent unit, separate from any movement device of the platform. 
     WO2016/116771 describes a craft with an aft hatch which is mobile between a vertical position closed on an aperture of an aft opening, and a horizontal position, in which it reaches the water. This hatch is moved by devices with articulated arms which are subjected to actuators. Between these arms there are present mobile elements which are hinged on these arms, which, in the horizontal position of the hatch, define a plurality of steps. The movement of these mobile elements is obtained by means of further units, which are hinged to one another, and are subjected to further actuator units which thus permit the rotation of these elements which, as stated, when the hatch is horizontal, define steps, whereas when the hatch is vertical they are also disposed vertically, rotated and lying on the same plane. 
     This known solution is complex, it has substantial dimensions, and requires large stern spaces in order to be able to position the mobile elements and their movement units. 
     U.S. Pat. No. 7,162,969 describes a craft with a mobile stern platform which can be placed in at least two positions of work, i.e. a first position close to a stern bridge of the boat, and a second position lowered towards the water. The platform slides on straight guides, and is superimposed on fixed steps provided in the hull at the stern of the boat, which steps are released when the platform moves towards the second position. This solution uses fixed steps provided in the hull, and which substantially occupy all of the stern, these steps being independent elements on said stern. In addition, the platform slides on inclined guides which are provided in the stern, and is not detached from the hull during this movement. 
     SUMMARY OF THE INVENTION 
     The objective of the present invention is to provide a craft, particularly a watercraft or boat, with a mobile aft platform and with a device for movement of the platform with a pantograph with an articulated quadrilateral, which is improved relative to the similar known crafts. 
     In particular, the objective of the invention is to provide a craft of the aforementioned type with a mobile platform which can be reached by means of steps when it is in the second position of work immersed at least partly in the water, wherein the presence of the steps is compact, and wherein these steps are obtained in a simple manner, without requiring large surfaces available in the aft part of the hull, and without implementing or adding other components in use. 
     Another objective of the invention is to provide a craft of the aforementioned type wherein every movement device of the platform can be obtained simply, and can be used where it is wished to move the platform with a non-linear movement device, and which has limited dimensions. 
     These objectives and others which will become apparent to persons skilled in the art are achieved by a craft according to the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For better understanding of the present invention, purely by way of non-limiting example, the following drawings are appended, in which: 
         FIG. 1  shows an example of a perspective view of the stern of a craft (in particular a watercraft) produced according to the invention, with a mobile platform in a first position of work; 
         FIG. 2  shows a perspective view from below of the stern of the craft in  FIG. 1 ; 
         FIG. 3  shows a perspective view of the stern of the craft in  FIG. 1 , but with the platform in the second position of work; 
         FIG. 4  shows a view similar to that of  FIG. 1 , exploded and with some parts removed the sake of greater clarity; 
         FIG. 5  shows a perspective view of a part of the craft in  FIG. 1 ; and 
         FIG. 6  shows a perspective view from below of a variant of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the aforementioned figures, a craft according to the invention is generally indicated as  1 , and comprises a hull  2  with a stern and an aft area  4 . In the stern  3  there is advantageously provided an aperture  5  which leads to an aft opening  6  preferably placed below a bridge  7 . The aperture  5  of the aft opening is closed at the bottom in the embodiment shown by a hatch  8  associated with a mobile stern platform  9 . 
     This platform can adopt at least two positions of work: in a first position ( FIGS. 1 and 2 ) the platform is substantially extracted from the water (or is placed slightly above the surface of the water) on which the boat is placed, and in this case, the hatch  8 , placed below the platform (see  FIG. 2 ), closes the aperture  5  at the bottom. It should be noted that the hatch  8  has an end part  10  which is formed such as to obtain lower adherent closure of this aperture  5 , in particular by means of an end position  11  thereof. It will be appreciated that the aperture  5  is closed at the top by another hatch  8 A (shown closed in  FIGS. 1  and  3 ) which is mobile in any known manner. In a second position of work ( FIG. 3 ), the platform  9  is immersed in the water and is placed below the aperture  5  of the opening  6 , with reference to the level of the water, which can thus at least reach a lower edge of the aperture  5  (in a direction parallel to the stern  3 ) and permit entry into the water and extraction therefrom of any tender (not shown) which may be admitted into the opening  6 . 
     The platform  9  moves relative to the hull by means of at least one movement device  15  (two in the figures) of the pantograph type, i.e. of the type which distances said platform from the hull  2  when it is open. The number of movement devices depends on the dimensions of the platform  9 , and on whether it is completely mobile, or alternatively only a part of it can be moved relative to another part which is secured on the hull. 
     In order to reach the platform in its second position of work, at least one of the movement devices  15  (both in the figures) comprises a fixed body  16  with at least one fixed step  17  (two in the figures), at least one second step  18  (which is mobile) being present in a structure  19  with an articulated quadrilateral of the movement device  15  with a pantograph supporting the platform  9  directly; said structure  19  is integral with this body  16  (see  FIG. 4  and  FIG. 5 ). 
     In other words, said movement device contains in itself the steps which make it possible to reach the platform  9  when it is immersed in the water, said steps being accessible when the device with a pantograph extends, and being covered by the structure  19  with an articulated quadrilateral when the device  15  is folded back. 
     This makes it possible to obtain a simple and compact structure for providing the steps for access to the platform  9  in the second position of work. It should also be noted that these steps  17  and  18  are placed in line with fixed steps  22  provided directly in the stern  3 , and which make it possible to reach the platform  9  when it is in the first position of work (from the bridge  7 ). In other words, the steps  17  and  18  follows the fixed steps  22  consecutively. 
     More particularly, each movement device  15  shown in the figures comprises the body  16  which is altogether distinct and autonomous relative to the structure (and therefore with respect to the hull  2 ) of the craft  1  (see  FIG. 4 ) and is secured inside a recess or seat  26  of the stern  3  by any known means. In the figures, the body  16  comprises a frame  29  which supports the fixed steps  17 . The frame  29  supports hinged external arms  30  which have first and second ends  31  and  32 ; the end  31  is hinged at  33  on the frame  29  and the (second) end  32  is hinged at  34  on a plate  35  which is secured on the platform  9 . 
     With the frame  29  there are associated internal arms  36  supporting the mobile step  18 . These arms, which are connected by a plate  38 , are hinged at  39 , by means of a first end  40 , on the frame  29 , and by means of a second end  43  they are hinged at  44  on the plate  35 . Small intermediate arms  46  can connect the external arms to the internal arms when the kinematics of the system necessitate this. 
     In the case presented, the plate  35  supports a transverse pin  50 , to which there is connected an actuator unit  51 , such as an oleodynamic or pneumatic or hydro-pneumatic cylinder, or a cylinder of another type such as electrical or with a rotary mechanism. In particular, a first part of this unit  51  (for example a piston) is connected to this pin  50 , whereas the second part (for example the cylinder) is connected to a transverse pin  53  connecting the internal arms  36 . 
     In the variant in  FIG. 6 , the plate  35  is common to the two devices  15  represented, and below it is placed a single actuator  51  for both said devices  15 . 
     The external arms  30  and the internal arms  36  define the structure  19  with an articulated quadrilateral previously referred to. 
     At the moment of actuation of each actuator unit  51  in order to move the platform from the first position of work ( FIGS. 1 and 2 ) to the second position of work ( FIG. 3 ), the arms  30  and  36  rotate around the hinges or pins  33  and  39  (respectively) which connect them to the fixed frame  29 , whereas the platform  9  is detached from the hull  2  supported by each plate  35  (on which there are hinged the arms  30  and  36 ). With the rotation of the two arms  30  and  36 , including also the one containing the step  18 , around the pins  33  and  39  of the body  16 , the translation with a circular trajectory of the platform  9  is transmitted by means of hinging at  34  and  44 . When the platform  9  reaches the second position of work, the step is then positioned in line with the fixed steps  17  of the body  16  (i.e. with their flat part  62  in the position of use parallel to the flat parts  61  of the fixed steps  22 ). Vice versa, when the platform  9  is taken to the first position of work, the rotation of the arms of the articulated quadrilateral  19  takes the flat part  60  of the mobile step  18  into the vicinity of the hull  2 , whereas said structure  19  is positioned in the vicinity of the hull, accommodating the fixed steps inside itself. 
     Thanks to the above-described solution, there is a simple and compact embodiment of steps which make it possible to reach the platform  9  easily when it is in its second position of work, by coming down from the bridge  7  (and vice versa) by using the space of the movement device. This device thus incorporates steps for reaching this platform. 
     The above-described solution can be applied to stern spaces which do not have enough room to accommodate elsewhere the steps or also their stern space without a storage unit. 
     Finally, it should be noted that the movement device  15  can be pre-assembled, and then be connected to the hull only after the device has been obtained. This facilitates the creation of the actuator device “with incorporated steps” and implementation of the normal “unloaded” operating tests without the presence of the platform (or the hull). 
     A preferred embodiment of the invention has been described. However, others can also be provided, such as those which have additional mobile and/or fixed steps, or which have components selected according to the type of boat on which the invention is applied. These solutions are also considered to be included in the scope of the present document.