FIELD OF THE INVENTION

This invention relates to a lift assembly for a watercraft. More particularly, this invention relates to a lift assembly for a watercraft, which can be used for raising and lowering a tender for the watercraft.

BACKGROUND OF THE INVENTION

Lift assemblies for tenders are usually mounted at a stern of a watercraft, for example, on a transom of the watercraft. Generally, such lift assemblies include a platform for supporting the tender as it is raised from a lowered condition on the water to a raised condition above a deck of the watercraft.

Passengers to be conveyed by the tender can board the tender or disembark from the tender when the tender is in a raised position above the deck, in an intermediate position in which the platform is generally aligned with the deck, or in a lowered position in which the tender is on the water.

It can be difficult and dangerous for a passenger to board or disembark the tender. In the raised or lowered conditions, a vertical distance between the tender and the deck may require that the passenger climb up onto the deck or jump down from the tender onto the deck. This may not be possible for passengers who are elderly or infirm. This is exacerbated by wet surfaces. Thus, an operator needs to adjust a position of the tender as best as possible to suit the passengers. Furthermore, there can be a gap between the transom and the tender, which creates a risk of injury to the passenger.

SUMMARY OF THE INVENTION

According to aspect of the invention, there is provided a lift assembly for a watercraft, the lift assembly comprising: a support structure that is mountable on the watercraft; a platform linkage assembly having a static end that is pivotally connected to the support structure; a platform assembly, a dynamic end of the platform linkage assembly being connected to the platform assembly, the platform linkage assembly being configured for displacement of the platform assembly between a lowered condition and a raised condition, while maintaining the platform assembly in a substantially consistent angular orientation relative to the support structure; a drive mechanism having a static end that is pivotally mounted to the support structure, and a dynamic end that is pivotally mounted to the linkage assembly, the drive mechanism being operable to drive the platform between the lowered and raised conditions; a step linkage assembly that is pivotally connected to the support structure and to the platform linkage assembly to be driven by the platform linkage assembly; and a step assembly interposed between the support structure and the platform assembly and connected to the step linkage assembly to be driven between raised and lowered conditions, the step linkage assembly being configured so that an extent of displacement of the step assembly is less than that of the platform assembly, such that the step assembly can facilitate access to a tender on the platform assembly, in use.

The platform linkage assembly may include at least one drive arm pivotally connected to the support structure at a static end and to the platform assembly at a dynamic end. At least one guide arm may be pivotally connected to the support structure at a static end and to the platform assembly at a dynamic end. Axes of rotation of the static ends of the drive and guide arms may lie in a plane that is parallel to a plane in which axes of rotation of the dynamic ends of the drive and guide arm lie so that the platform linkage assembly is a parallelogram mechanism and the platform assembly maintains the substantially consistent angular orientation relative to the support structure as the drive and guide arms are pivoted with respect to the support structure.

The step linkage assembly may include at least one upper link arm pivotally connected to the support structure at a static end and to the step assembly at a dynamic end. At least one lower link arm may be pivotally connected to the support structure at a static end and to the step assembly at a dynamic end. Axes of rotation of the static ends of the upper and lower link arms may lie in a plane that is parallel to a plane in which axes of rotation of the dynamic ends of the upper and lower link arms lie so that the step linkage assembly is a parallelogram mechanism, and the step assembly maintains a consistent angular orientation relative to the support structure as the link arms are pivoted with respect to the support structure.

The step linkage assembly may include a rocker-slider linkage assembly that interconnects the step assembly and the platform linkage assembly. The rocker- slider linkage assembly may be configured so that reciprocal pivotal movement of the platform linkage assembly drives the step assembly between raised and lowered conditions such that the step assembly is positioned above the platform assembly when both are in a lowered condition and below the platform assembly when both are in a raised condition.

The rocker-slider linkage assembly may include at least one slider arm that defines an elongate slot extending partially along a length of the slider arm from one of the lower and upper ends of the slider arm. The slider arm may be pivotally connected to the platform lift assembly at a lower end and pivotally connected to the step assembly at an upper end, pivotal connection of said one of the lower and upper ends being provided by the slot. Thus, when the platform linkage assembly is displaced upwardly, an initial stage of such displacement is accommodated by the, or each, slider arm with the step assembly being stationary. This creates the lesser displacement of the step assembly mentioned above.

The platform lift assembly may include one drive arm, the dynamic end of the drive mechanism being connected to the drive arm to pivot the drive arm upwards and downwards so that the platform assembly is driven upwardly and downwardly. The platform linkage assembly may include two guide arms, with the drive arm interposed between the guide arms.

The static end of the drive arm may be positioned below the static ends of the guide arms, and the dynamic end of the drive arm may be positioned below the dynamic ends of the guide arms.

The drive mechanism may include an actuator, in the form of a hydraulic actuator or cylinder that is pivotally connected to the support structure at a static end and pivotally connected to the drive arm at a dynamic end. The static end may be above the dynamic end so that retraction of the actuator pivots the drive arm upwardly to raise the platform assembly.

The support structure may include a bracket that is fastened to a transom of the watercraft. The static ends of the drive arm, the guide arms, and the upper and lower link arms may be connected to the bracket.

The bracket may include a base that is fastened to the transom of the watercraft, and a mounting arrangement that projects from the base, the static ends of the drive arm, the guide arms, and the upper and lower link arms being pivotally connected to the mounting arrangement, with the static end of the guide arm being positioned below the static ends of the guide arms, which are positioned below the static ends of the lower link arms, which themselves are positioned below the static ends of the upper link arms.

The mounting arrangement may include four generally parallel mounting plates that extend orthogonally from the base so that the base and the plates define three vertically extending channels in the form of two outer channels and a central channel interposed between the outer channels.

The static end of the drive arm may be positioned in the central channel, and pivotally mounted to the plates, and the static ends of respective guide arms may be positioned in respective outer channels, above the static end of the drive arm, and pivotally connected to the plates.

The static ends of the upper and lower link arms may be positioned in respective outer channels, and pivotally connected to the plates.

The static end of the hydraulic cylinder may be positioned in the central channel, above the static ends of the upper and lower link arms, and pivotally connected to the plates.

The platform assembly may include a carrier and a platform upon which the tender can be supported.

A mounting arrangement may project downwardly from the carrier, the dynamic ends of the drive arm and the guide arms being pivotally connected to the mounting arrangement with the dynamic end of the drive arm being below the dynamic ends of the guide arms.

The mounting arrangement may include four generally parallel mounting plates that extend orthogonally from the carrier, so that the carrier and the mounting plates define three channels in the form of two outer channels and a central channel interposed between the outer channels.

The dynamic end of the drive member may be positioned in the central channel, and pivotally connected to the plates, and the dynamic ends of the guide arms may be positioned in respective outer channels, and pivotally connected to the plates.

The step assembly may include at least one step. A mounting arrangement may project downwardly from a, or a lower, step of the step assembly, the step linkage assembly including two upper link arms, the dynamic ends of which are pivotally connected to the mounting arrangement, and two lower link arms, the dynamic ends of which are pivotally connected to the mounting arrangement.

The mounting arrangement may include two mounting plates that are fixed to and extend downwardly from a lower step of the step assembly, the dynamic ends of the upper and lower link arms being pivotally connected to the mounting plates.

The invention extends to a watercraft that includes the lift assembly described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a three-dimensional view of an embodiment of a lift assembly for a watercraft, in accordance with the invention, in a raised condition.

Figure 2 shows the lift assembly in an intermediate condition.

Figure 3 shows the lift assembly in a partially lowered condition.

Figure 4 shows the lift assembly in a fully lowered condition.

Figure 5 shows a view of an upper part of the lift assembly in the partially lowered condition.

Figure 6 shows a view of a lower part of the lift assembly in the raised condition.

Figure 7 shows a view of a rocker-slider linkage assembly of the lift assembly.

DETAILED DESCRIPTION

In the drawings, reference numeral 10 generally indicates an embodiment of a lift assembly for a watercraft, in accordance with the invention, in a raised condition.

The lift assembly 10 is, in use, mounted on a transom 12 of the watercraft and is used for raising and lowering a tender for the watercraft. It is to be appreciated that the lift assembly 10 can be used for raising and lowering other forms of supplementary watercraft, such as a lifeboat, recreational watercraft, for example, jet skis, etc.

The lift assembly 10 includes a support structure in the form of a bracket 14 that is mounted on the transom 12. The lift assembly 10 includes a platform linkage assembly 16 that is pivotally connected to the bracket 14 and to a platform assembly 18. The platform linkage assembly 16 is configured for reciprocal displacement of the platform assembly 18 between a raised condition (figure 1) and a lowered condition (figure 4), while maintaining the platform assembly 18 in a substantially consistent angular orientation relative to the bracket 14. In these embodiments, this is a substantially horizontal orientation. It is to be appreciated that other orientations may also be applicable.

The lift assembly 10 includes a drive mechanism in the form of a hydraulic actuator or cylinder 20 having a static end 22 (figure 5) that is pivotally mounted to the bracket 14, and a dynamic end 24 (figure 6) that is pivotally mounted to the platform linkage assembly 16. The hydraulic actuator 20 is operable to drive the platform assembly 18, via the platform linkage assembly 16, between the lowered and raised conditions.

A step linkage assembly 26 (figure 1 ) is pivotally connected to the bracket 14 and to the platform linkage assembly 16 to be driven by the platform linkage assembly 16.

A step assembly 28 (figure 4) is interposed between the bracket 14 and the platform assembly 18 and is connected to the step linkage assembly 26 to be driven between raised and lowered conditions. The step linkage assembly 26 is configured so that an extent of displacement of the step assembly 28 is less than that of the platform assembly 18 such that the step assembly 28 can facilitate access to a tender supported by the platform assembly 18.

The platform linkage assembly 16 includes a drive arm 30 pivotally connected to the bracket 14 at a static end 32 and to the platform assembly 18 at a dynamic end 34. The platform linkage assembly 16 includes two guide arms 36 pivotally connected to the bracket 14 at static ends 38 and to the platform assembly 18 at dynamic ends 40.

The bracket 14 includes a base 42 that is fastened to the transom 12. A mounting arrangement in the form of four generally parallel mounting plates 44.1 , 44.2, 44.3 and 44.4 (figure 5) extends orthogonally from the base 42 so that the base 42 and the plates 44 define three vertically extending channels in the form of two outer channels 46 and a central channel 48 interposed between the outer channels 46.

The static end 32 of the drive arm 30 is pivotally mounted in the central channel 48 between the plates 44.2, 44.3 with a pivot pin 50 that extends through the plates 44.2, 44.3 and the static end 32. Each static end 38 of the guide arms 36 is pivotally mounted in a respective outer channel 46 between the plates 44.1 , 44.2 and 44.3, 44.4, respectively, with pivot pins 52.

The platform assembly 18 includes a carrier 54 and a platform 56, on which the tender can be supported. Here, the platform 56 is shown as a generic flat structure. It is to be appreciated that the platform 56 can take various forms depending on the support requirements for the tender or any other supplementary watercraft that is to be supported by the platform 56.

A mounting arrangement in the form of four generally parallel mounting plates 58.1 ,

58.2, 58.3 and 58.4 (figure 2) extends orthogonally from the carrier 54 so that the carrier 54 and the plates 58 define three channels in the form of two outer channels 60 and a central channel 62 interposed between the outer channels 60. The plates

44.1 . 44.2, 44.3 and 44.4 and the plates 58.1 , 58.2, 58.3 and 58.4 lie in respective common planes. The dynamic end 34 of the drive arm 30 is pivotally mounted between the plates 58.2, 58.3 with a pivot pin 64 (figure 2) that extends through the plates 58.2, 58.3 and the dynamic end 34. Each dynamic end 40 of the guide arms 36 is pivotally mounted between the plates 58.1 , 58.2 and 58.3, 58.4, respectively, with coaxial pivot pins 66 (figure 1 ).

The plates 58.2, 58.3 include downwardly and rearwardly extending lobes 59.1 , 59.2 (figure 3). The pivot pin 64 extends through the lobes 59 to be below and rearward of the pivot pins 66. The mounting plates 58.2, 58.3 include downwardly and rearwardly extending lobes 61 .1 , 61 .2. The pivot pin 50 extends through the lobes 61 to be below and rearward of the pivot pins 52. Thus, the pivot pins 50, 52, 64, 66 are positioned so that axes of rotation of the static ends 32, 38 lie in a plane that is parallel to a plane in which the axes of rotation of the dynamic ends 34, 40 lie. It follows that the platform linkage assembly 16 is a parallelogram mechanism and the platform assembly 18 maintains a consistent angular orientation relative to the bracket 14 as the drive and guide arms 30, 36 are pivoted with respect to the bracket 14. In particular, the pivot pins 50, 52, 64, 66 are positioned so that the platform assembly 18 maintains an orthogonal orientation relative to the transom 12, which, in use, is horizontal. It will be appreciated that a position of the carrier 54 with respect to the platform 56 can vary to adjust the orientation of the platform 56.

The pivot pins 50, 64 are respectively positioned below and rearwardly of the pivot pins 52, 66. Thus, the static and dynamic ends 32, 34 of the drive arm 30 are below and rearward of the static and dynamic ends 38, 40 of the guide arms 36. The drive arm 30 includes a forward portion 68 that terminates at the static end 32, a rearward portion 70 that terminates at the dynamic end 24, and an intermediate portion 72 interposed between the forward and rearward portions 68, 70. The guide arms 36 each have a forward portion 74 that terminates at the static end 38 and a rearward portion 76 that terminates at the dynamic end 40.

The hydraulic actuator 20 includes a sleeve 78 (figure 2) that is pivotally connected to the bracket 14 with a pivot pin 80 that extends through the plates 44.2, 44.3. The pivot pin 80 is positioned at or near an upper end of the bracket 14 so that the actuator 20 can extend downwardly from the bracket 14 towards the drive arm 30. The actuator 20 includes a piston 82 that is reciprocal with respect to the sleeve 78. Two connecting plates 84 are fixed to the drive arm 30 at a junction of the forward and intermediate portions 68, 72. The piston 82 is pivotally connected between the plates 84 with a pivot pin 86 that extends through the plates 84 and is pivotally connected to the piston 82.

In figure 1 , the platform assembly 18 is in a fully raised condition, and in figure 4 the platform assembly 18 is in a fully lowered condition. As is apparent from the figures, an angular orientation, and dimensions of the forward and intermediate portions 68, 72 of the drive arm 30 accommodates a required length of the actuator 20 for the full range of movement of the platform assembly 18 between the raised and lowered conditions.

The step assembly 28 includes a mounting arrangement in the form of two mounting plates 90.1 , 90.2 that are fixed to and extend downwardly from a step, for example, a lower step 92 (figure 5).

The step linkage assembly 26 includes two upper link arms 88 that are coaxially and pivotally connected to the mounting plates 44.1 , 44.2 and 44.3, 44.4, respectively, at static ends 94, with pivot pins 95 that extend through the plates 44,1 , 44.2 and 44.3, 44.4, respectively, and the static ends 94 (figure 6). The upper link arms 88 are coaxially and pivotally connected to the mounting plates 90.1 , 90.2 at dynamic ends 96 with a pivot pin 98 that extends through the plates 90.1 , 90.2, respectively. The step linkage assembly 26 includes two lower link arms 100 (figure 2) that are coaxially and pivotally connected to the mounting plates 44.1 , 44.2 and 44.3, 44.4, respectively, at static ends 102, with pivot pins 103 that extend through the plates 44,1 , 44.2 and 44.3, 44.4, respectively (figure 6). The lower link arms 100 are coaxially and pivotally connected to the mounting plates 90.1 , 90.2 at dynamic ends 104 with pivot pins 106 that extend through the plates 90.1 , 90.2, respectively. The pivot pins 95, 98, 103, 106 are positioned so that axes of rotation of the static ends 94, 102 lie in a plane that is parallel to a plane in which the axes of rotation of the dynamic ends 96, 104 lie. In this embodiment, the pivot pins 103, 106 are downwardly and rearwardly positioned with respect to the pivot pins 95, 98. Thus, the step linkage assembly 26 is a parallelogram four-bar linkage and the step assembly 28 maintains a consistent angular orientation relative to the bracket 14 as the link arms 88, 100 are pivoted with respect to the bracket 12.

In this embodiment, the step assembly 28 includes the lower step 92 and an upper step 108 that is fixed above the lower step 92 with two mounts 110. It will be appreciated that a single step or three or more steps may also be appropriate depending on the application. Thus, in use, the consistent angular orientation of the step assembly 28 is such that the steps 92, 108 are maintained in a substantially horizontal orientation.

A rocker-slider linkage assembly 112 interconnects the step assembly 28 and the platform linkage assembly 16. The rocker-slider assembly 112 is configured so that reciprocal pivotal movement of the platform linkage assembly 16 drives the step assembly 28 between raised and lowered conditions such that the step assembly 28 is positioned above the platform assembly 18 when both are in a lowered condition and below the platform assembly 18 when both are in a raised condition.

The rocker-slider assembly 112 includes two slider arms 114. Each slider arm 114 defines an elongate slot 116 that extends partially along a length of the slider arm 114 from an upper end 118 towards a lower end 120 (figure 6). A pivot pin 122 is received through each slot 116 and the connecting plates 90.1 , 90.2 to both slide and pivot with respect to the slider arms 114. To that end, a collar 115 is mounted on each end of the pivot pin 122 (figure 7). Each collar 115 defines an annular recess 117 that accommodates said length of the slider arm 114 that defines the slot 116. Aligned pivot mounts 124 are fixed to respective guide arms 36. The lower ends 120 of the slider arms 114 are pivotally connected to the respective guide arms 36 with pivot pins 126 that extend through arms 128 of the pivot mounts 124.

In figure 4, with the platform linkage assembly 16 in the fully lowered condition, the pivot pins 122 are at the upper ends 118 of the slider arms 114, bearing against upper ends of the slot 116. In figure 3, with the platform linkage assembly 16 pivoted partially upwardly by retraction of the piston 82, the pivot pins 122 are displaced along the length of the slots 116 to bear against lower ends of the slot 116. Thus, an initial stage of upward movement of the platform linkage assembly 16 from the position shown in figure 4 to the position shown in figure 3 is independent of the step assembly 28, as the pivot pins 122 slide from the upper ends of the slots 116 to the lower ends. Thereafter, each slider arm 114 can transfer upward pivotal movement of the platform linkage assembly 16 to the step assembly 28, via the slider arms 114, to pivot the step assembly 28 upwardly.

The transom 12 includes an upper ledge 128 that extends rearwardly to provide step access to a deck of the watercraft. The steps 92, 108, the step linkage assembly 26 and the rocker-slider assembly 112 are configured so that, in the fully raised condition (figure 1 ) the upper step 108 is interposed between the platform 56 and the ledge 128 allowing a person to step down from the tender onto the upper step 108 and then onto the ledge 128 or step up to the tender from the deck. Instead, the platform 56 can be brought into a position (figure 2) where the platform 56, the upper step 108 and the ledge 128 are aligned to facilitate access to the deck without the need to step up or down to the ledge 128. In this condition, the step 108 closes a gap that would otherwise exist between the tender and the deck, so mitigating risk of the passenger stepping into the gap. Alternatively, the platform 56 can be partially lowered (figure 3) or fully lowered (figure 4) to allow the person to transition to and from the deck using just the upper step 108 (figure 3), or both the upper and lower steps 108, 92 (figure 4).

The lift assembly 10 improves the safety and convenience of passengers embarking or disembarking a tender. The step assembly 28 obviates the need for a passenger to move directly from the tender and onto a deck of the watercraft, so removing the need for the passenger to climb up onto the deck or jump down onto the deck when the platform assembly 18 is in the lowered or raised conditions, respectively. Furthermore, the step assembly 28 fills a gap between the platform assembly 18 and the deck which would result without the step assembly 28.

The appended claims are to be considered as incorporated into the above description.

Throughout this specification, reference to any advantages, promises, objects or the like should not be regarded as cumulative, composite, and/or collective and should be regarded as preferable or desirable rather than stated as a warranty.

Throughout this specification, unless otherwise indicated, "comprise," "comprises," and "comprising," (and variants thereof) or related terms such as "includes" (and variants thereof)," are used inclusively rather than exclusively, so that a stated integer or group of integers may include one or more other non-stated integers or groups of integers.

Words indicating direction or orientation, such as “front”, “rear”, “back”, “above”, “below”, etc, are used for convenience. The inventor(s) envisages that various embodiments can be used in a non-operative configuration, such as when presented for sale. Thus, such words are to be regarded as illustrative in nature, and not as restrictive.

Features which are described in the context of separate aspects and embodiments of the invention may be used together and/or be interchangeable. Similarly, features described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.

It is to be understood that the terminology employed above is for the purpose of description and should not be regarded as limiting. The described embodiments are intended to be illustrative of the invention, without limiting the scope thereof. The invention is capable of being practised with various modifications and additions as will readily occur to those skilled in the art.