Patent Description:
In all boatyards where there the construction or repair and storage of boats is undertaken, it is necessary to be able to pick up, lift and move these boats from the pier to the storage area or the boatyard. This requirement has already been met to a large extent using various hoisting equipment, variously configured, in particular: jib cranes and boat trolleys, rail mounted straddle transporters or rubber-tyred gantry cranes, hereinafter also referred to generically as: mobile boat hoists, all presenting different and varied limitations and drawbacks.

Currently, the existing state-of-the-art solutions for lifting and transporting boats are the following: jib cranes and boat trolleys, rail mounted straddle carriers, boat hoists on jetties, boat hoists on slipways.

The solution of the jib cranes and boat trolleys, schematised in a manner indicated in the attached <FIG> is adopted in the boatyard for reasons of space or when the boats are fairly light.

The jib crane is used to attach to the hull of the boat with special straps and lift it and then deposit it on a platform trolley that then transports it to the storage area.

This installation entails large and expensive work for the construction of the foundation base that serves as ballast and to stabilise the jib crane.

It is also a fixed application that has a limited range of action.

The solution of the rail mounted cranes is indicatively shown in the attached <FIG>, and they are fixed confined structures sliding on tracks fixed in the ground.

There can be numerous handling requirements in boatyards and the use of these structures is very expensive since slide rails need to be positioned along the entire length of the operation of the machine necessarily restricting the use of the area of the boatyard. In addition, they are an obstacle to the passage of other machinery that has to cross the same area, whether they protrude from the ground or are recessed into the ground and placed inside a pit.

By the term mobile boat hoists we mean wheeled trolley-type gantry cranes that are effectively able to guarantee the free movement of the boats within the area of a boatyard.

Mobile boat hoists are also effective for overcoming slight slopes, and they are extremely versatile since they are equipped with rubber wheels rotating around their axis and so can be steered. These structures can operate on docks equipped with slipways or on docks with wharves.

The boat hoists on jetties, see the attached <FIG>, is a hoist operating on jetties; the most commonly used lifting structure, however, can only be used where there are two jetties with an adequate capacity and at a pre-fixed distance that establishes the track of the hoist itself.

This type of system provides an internal distance for certain widths of the hull of the boats to be stowed and consequently their weight; for this reason, boats with larger hulls cannot be lifted.

The construction of jetties is very expensive and has a considerable environmental impact.

In order for all the storage systems mentioned above to be fully functional, must have a properly constructed fixed infrastructure and have the possibility to work only at a single point of pick-up of the boat from its berth.

A boat hoist on a slipway, see the attached <FIG>, is a mobile boat hoist operating on a slipway, which must partially enter the water to lift the boat, and so for this reason all the components coming into contact with the water must be watertight and the propulsion unit must be located above the immersion level.

This system involves the construction of a slipway with a slight slope and therefore involves considerable environmental impact and a substantial use of natural area.

The construction of a boat hoist that operates on a slipway is very expensive, as is the masonry work for the construction of the slipway.

Another characteristic of this type of system is that the boat hoist requires continuous maintenance to protect the parts that go into the water from corroding and the continuous maintenance and cleaning of the slipway to remove algae and sludge deposits that would reduce the adhesion of the tyres of the hoist and thereby causing dangerous slippage during transit.

<CIT> discloses a mobile boat hoist equipped with longitudinal members comprising at least one pair of portal frames spaced apart from one another, a track connected to the top of each frame, at least one spacer crossbeam, connecting said pair of frames, at least one lifting trolley that can slide on said track, each of said frames further comprises at least one lower longitudinal member connecting at least two vertical supports or legs in the lower part, and at least one upper longitudinal member connecting said vertical supports in the upper part, where said pair of frames is joined in a spaced apart manner to a first end side from said spacer crossbeam, in the upper part of each frame, where said track of said one or more lifting trolleys is connected with said each upper longitudinal member on each upper longitudinal member, near the end of the second side, opposite to the end of the first joining side of said spacer crossbeam.

The main purpose of the present invention is to provide a gantry crane or mobile boat hoist that can overcome all the drawbacks of the prior art.

An important purpose of the present invention is to make available a gantry crane that can pick up boats without the need to construct infrastructure and therefore preserve as much area as possible near the pier where the boat will be lifted.

Another object of the present invention is to be able to use the entire area of the quay and so not having a single lifting area several boat hoists can be operated at the same time.

A further object of the present invention is to be able to optimise the boatyard storage areas and to be able to position the boats one in front of another and in points that would otherwise be inaccessible with the normal equipment used.

Another object of the present invention is to make available a mobile boat hoist that does not need a trolley for transporting the boat after lifting it.

A further object of the present invention is to make available a mobile boat hoist that does not require tracks fixed in the ground.

Another object of the present invention is to make available a boat hoist that easily adapts to the pre-set distance of the jetties.

An important object of the present invention is to make available a boat hoist that can lift a boat even where there is no quay.

A further object of the present invention is to make available a boat hoist that does not require a quay that has a slipway.

All the above objects are achieved by the boat hoist that is the object of the present invention, which is mainly characterised by the particularities of the main claim.

The mobile boat hoist of the invention comprises the features of claim <NUM>.

Advantageously, said mobile boat hoist comprises moving devices connected with the lower part of the frame, allowing said boat hoist to move autonomously.

Advantageously, said moving devices are steerable, allowing the boat hoist to change the direction of its movement.

Advantageously, on at least one retractable longitudinal member, on the free end, and opposite to that where the hinging with the upper member is, at least one connection beam is hinged that joins with the free end of the retractable longitudinal member of the opposite frame or that is connected with an identical connecting beam hinged on the end of the retractable longitudinal member of the opposite frame, maintaining the verticality and mutual spacing between the pair of frames also after the lifting of the boat carried out by said lifting trolleys, placed on the track of the retractable longitudinal member.

Advantageously, said connection beam joint consists of a male slider moved by an actuator that joins with a female housing on the end of the retractable longitudinal member of the opposite frame or on the free end of the connection beam hinged on the retractable end of the opposite frame, facilitating the relative connection. Advantageously, on each track there are two or more trolleys for lifting the boat, which slide on each track at a pre-set distance from each other, which can be adjusted to adapt to the boat to be lifted.

Advantageously, the rotary movement between the upper longitudinal member and the retractable longitudinal member takes place on a hinge with a horizontal axis on the common end of the said upper and retractable longitudinal members by means of an actuator hinged to one end on the retractable longitudinal member and with the opposite end hinged fixed on the upper longitudinal member or on a connecting rod fixed to the upper longitudinal member.

Advantageously said stiffening devices include a strut moved by an actuator with a fulcrum of a first end hinged on the upper longitudinal member or on the retractable longitudinal member and having a second end from which a first stay departs towards the rear side of the upper longitudinal member and one stay towards the front side of the overhang of the retractable longitudinal member.

Advantageously, near the first end of said strut, the free end of said connecting rod and the first end of said actuator for rotating the retractable longitudinal member are mounted, so that during the alignment of the retractable longitudinal member the lifting by rotation of the strut can occur, from a first position leaning against the upper longitudinal member to the maximum rotation allowed by the length of the first stay.

The aforementioned stays serve to stabilise the upper longitudinal members with the retractable longitudinal members during the maximum rotation and alignment phase; they are divided into two segments and joined by an adjustment hinge that allows them to be correctly tensioned and closed during the rest phase.

The technical characteristics of the invention, according to the aforementioned objects, can be clearly seen from the content of the claims below and the relative results will be apparent in the detailed description that follows with reference to the drawings, which illustrate a purely exemplary and non-limiting embodiment, in which:.

With reference to the drawings, the object of the invention consists of a mobile boat hoist equipped with retractable longitudinal members.

The boat hoist comprises a pair of spaced apart frames, where each frame comprises a lower longitudinal member <NUM> and an upper longitudinal member <NUM>. The corresponding ends of the lower longitudinal member <NUM> and of the upper longitudinal member <NUM> are connected by vertical supports or legs <NUM>.

Furthermore, at the ends of the lower longitudinal member <NUM>, in the lower part, two motorised steerable wheel carriers <NUM> are mounted and on one of the two lower longitudinal members the drive unit <NUM> is mounted.

Above the two lower longitudinal members <NUM> and more precisely at the four ends, in the upper part, four legs <NUM> are fixed.

At the front of the motorised wheel carriers <NUM>, at the front end of the lower longitudinal members <NUM>, there are two legs <NUM> that have two stabilising cylinders <NUM> inside them which serve as a support point to limit the load on the wheel carriers <NUM> in the phase when the boat is being lifted with the retractable longitudinal members <NUM> in their maximum opening and the trolleys <NUM> in their maximum gripping distance.

A first counterbalancing solution of the boat hoist provides that at the front, at the rear end of the lower longitudinal members <NUM>, there are two attachments <NUM> to which the cable ring <NUM> is fixed by means of the shackle <NUM> and a tensioner <NUM> that is firmly anchored to a retractable ring <NUM> fixed to the quay to counterbalance the weight of the boat to be lifted.

A second counterbalancing solution of the boat hoist provides that the anchoring can also take place to a suitably sized concrete block <NUM> simply resting on the quay, which can be transported and repositioned at any point of the quay itself with the boat hoist hooking it to the attachments <NUM>.

A third counterbalancing solution of the boat hoist provides that the counterbalancing of the weight of the boat to be lifted can also be carried out by suitably ballasting the rear legs <NUM>, the lower longitudinal members <NUM>, the crossbeam <NUM> and the upper longitudinal members <NUM> by inserting high specific weight metal grit inside them, or by providing metal plates to be fixed externally.

These last two solutions are preferable when, for any reason, it is not possible to anchor to the ground or there is a need to lift the boats at other points of the jetty.

At the upper ends of the four legs <NUM> there are two upper longitudinal members <NUM> that together with these latter make up the two lateral sides of the boat hoist.

Between the two sides, at the top, a crossbar <NUM> is fixed using the hinge <NUM>, which acts as a spacer and creates the trolley of the boat hoist.

The crossbar <NUM> can also be telescopic so that the trolley of the boat hoist can be changed.

The hinge <NUM> facilitates and reduces the assembly time of the boat hoist so that the number of cranes and work vehicles used can be reduced.

The upper members <NUM> are connected to the retractable longitudinal members <NUM> by means of the hinge <NUM> with a horizontal axis that allows a rotation between the two by <NUM>°; aligning them horizontally creates a straight track for the sliding of the lifting assembly composed of two trolleys <NUM> connected to each other by a telescopic structure <NUM> controlled by a hydraulic cylinder <NUM>.

The hydraulic cylinder <NUM> allows the distance between the two trolleys <NUM> to be changed and therefore also the spacing of the straps <NUM> so they can adapt correctly to the positioning of the hull of the boats to be lifted.

The trolley <NUM> is composed of a metal frame that slides by means of motorised wheels on the longitudinal members <NUM> and <NUM> along their entire length and by four winches <NUM> and four hook assemblies <NUM> where the lifting straps <NUM> are fixed.

The rotary movement between the upper longitudinal member <NUM> and the retractable longitudinal member <NUM> takes place by means of the hydraulic cylinder <NUM>, the connecting rod <NUM> and the strut <NUM>.

The stiffening devices of each retractable longitudinal member with the corresponding upper longitudinal member are hinged and collapsible and comprise struts and tie rods or shafts between each retractable longitudinal member and the frame to which said longitudinal member is hinged.

In particular, from the top of the strut <NUM> there is a stay <NUM> going towards the rear side and a stay <NUM> going towards the front side of the boat hoist.

The stays <NUM> and <NUM> are used to stabilise the upper longitudinal members <NUM> with the retractable longitudinal members <NUM> during the maximum rotation and alignment phase; they are divided into two segments and joined by means of an adjustment hinge <NUM> that allows them to be correctly tensioned and closed during the rest phase.

A first connection beam <NUM> is hinged to the external top of the retractable longitudinal members <NUM>, inside which the male slider <NUM> is housed, controlled by the hydraulic cylinder <NUM>, and a second connection beam <NUM> that carries the female housing.

Claim 1:
Mobile boat hoist equipped with retractable longitudinal members comprising at least one pair of portal frames (<NUM>, <NUM>, <NUM>) spaced apart from one another, a track connected to the top of each frame, at least one spacer crossbeam (<NUM>), connecting said pair of frames, at least one lifting trolley (<NUM>) that can slide on said track, wherein said mobile boat hoist comprises a retractable longitudinal member (<NUM>) hinged along a horizontal axis near an upper end of each frame, a track connected to each retractable longitudinal member (<NUM>), hinged and collapsible stiffening devices comprising connecting struts and tie rods between each longitudinal member and the frame to which said longitudinal member is hinged; each of said frames further comprises at least one lower longitudinal member (<NUM>) connecting at least two vertical supports or legs (<NUM>) in the lower part, and at least one upper longitudinal member (<NUM>) connecting said vertical supports (<NUM>) in the upper part, where said pair of frames (<NUM>, <NUM>, <NUM>) is joined in a spaced apart manner to a first end side from said spacer crossbeam (<NUM>), preferably in the upper part of each frame, where said track of said one or more lifting trolleys (<NUM>) is connected with said each upper longitudinal member (<NUM>); on each upper longitudinal member (<NUM>), near the end of the second side, opposite to the end of the first joining side of said spacer crossbeam (<NUM>), said retractable longitudinal member (<NUM>) is hinged that rotates from a first raised/near/adjacent position with respect to the upper longitudinal member (<NUM>) to a second extended position and in continuation of the upper longitudinal member (<NUM>), in alignment with the track of one or more lifting trolleys (<NUM>), creating an extended track extending from each upper longitudinal member (<NUM>) to the retractable longitudinal member (<NUM>).