GB2081211A

GB2081211A - A boat davit

Info

Publication number: GB2081211A
Application number: GB8121472A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-07-14
Filing date: 1981-07-13
Publication date: 1982-02-17

Abstract

A boat davit comprises a single fixed boat support arm 10, a cradle 13 and a slide panel 20 which is wider in its lower regions. Lifting ropes 11 from a winch 2 pass over pulleys 12 on the arm 10 and are attached to blocks 14 on the end of arms 17 of the cradle 13. The cradle 13 has a pair of series of rollers 13 arranged to run on the panel 20 and then down the side of the slip. A boat 3 is held in the cradle 13 by fixed length ropes 4 attached to the boat at 5 and maintained in the storage position by a support device 23 operated by handles 24 and ropes 25. <IMAGE>

Description

SPECIFICATION Boat davit This invention reiates to an improvement to a boat davit located on a deck for lowering a boat from its storage position into the water.

Conventionally, with the apparatus of this kind, a boat has had to be swung out of a ship by sloping a pair of arms hanging the boat and be lowered into the water by letting out hanging ropes. Therefore, it is not possible to lower a boat while a ship is sailing, and the ship needs to be in a stationary state for lowering operation.

Furthermore, the arms are heavily loaded because they hang a boat, and eventually the apparatus themselves become to be of a large size, and the two complicated operations of swinging a boat out of a ship and letting out ropes are not desirable from the safety standpoint.

Further, a conventionally known apparatus of this kind is such as one, which comprises a pair of fixed boat support arms, ropes which move through the aid of blocks attached to each end of the said arms for lifting and lowering a boat, a winch for the said rope operation, and a cradle attached on a side of a boat. On the both sides of the said cradle are attached a series of rubber rollers which move along the said respective arm through the operation of the above said ropes, and the boat is detachably connected to the edge of the above said cradle by ropes of a set length in the bow and stern areas. (Japanese Pat.

Publication No. 126199/1987.) However, as this apparatus uses a pair of boat support arms, which are heavy and large in size, it is difficult to install on a small ship.

Further, with this apparatus, a boat set on the cradle slides up and down along a pair of the boat support arms, and therefore, the boat may be dislocated when operated while the ship pitches and rolls severely. In other words, it is difficult to expect assured operations of this apparatus.

The first object of this invention is to provide a boat davit which is comparatively simple in its structure, easy to operate, light in weight, small in size, and yet capable of lowering a boat even when a ship is sailing.

And the other object of this invention is to provide a boat davit which can be operated in a stable condition even when the ship is in severe pitching and rolling movements.

In order to accomplish the afore-mentioned objects, this invention is featured in that the said apparatus comprises a fixed boat support arm, lifting ropes which move through the aid of pulleys attached to the ends of the said arm to lift and lower a boat, a winch to operate the said ropes, and a cradle which is located on a side of the boat and moves along the arm through the operation of the said ropes, the ends of which are connected to the upper part of the said cradle, the said cradle being provided on its both sides a series of rollers which move along the said arm, the boat being hung from the upper part of the said cradle by two hanging ropes of a set length, each of which is detachably attached to the boat at its bow and stern areas.

The drawing is to illustrate an example of the boat davit supporting a boat of this invention; FIGURE 1 is a front elevation and FIGURE 2 a side elevation.

Further explanations are given hereunder, referring to the drawing, on the examples of the boat davit of this invention. The boat davit of this invention has one boat support arm (10), as is shown in Figures 1 and 2, having two pulleys (12) on its ends to hang lifting ropes (11). This arm (10) is fixed almost vertically on the deck (1) of a ship, as illustrated in the drawing. Meanwhile, the apparatus (2) is a winch to operate the lifting ropes (11) which are hung on the pulleys (12) located on the support arm (10). And as is illustrated by the drawing, the boat davit of this invention includes a cradle (13) set on a side of the boat, at the upper edge of which cradle are installed two blocks (14) for hanging the lifting ropes and the ends of the lifting ropes (11) are connected thereto.And further, on the both sides of the cradle (13) are installed a series of rollers (15), which roll along the arm (10). These rollers are preferably made of rubber. At two optional positions of the boat (3), hooks (5) are fixed, and hanging ropes (4) of a set length connect the blocks (14) located on the upper part of the cradle (13) and the hooks (5) of the boat to support the boat.

The cradle (13) preferably comprises, as illustrated by Figure 1, a pair of'the roller support panels (16) having a series of rollers (15) respectively, arms (17) extending upward from each support panel, and beams (18) which reinforce and connect the support panel (16) to the arms (17) on both sides. And the rope fixing blocks (14) are fixed to the upper parts of each arm.

Further, the boat davit of this invention has a fixing bar (19) at an optional position, preferably below the middle position, of the boat support arm (10), fixed at a right angle to the said arm (10), and a slide panel (20) stretches slantly downward from the said fixing bar (19) for the cradle (13) to slide down thereon. Moreover, the slide panel (20) is designed to be wider at lower positions, hence a boat (3) can be lifted up or down in a stable state without slipping out of the panel (20). In the drawing, reinforce bars to the slide panel (20) are given the number (21), and the number (22) is side frames of the slide panel (20). The said side frames (22) are set only at upper part of the slide panel (20) to prevent the cradle (13) from slipping out.Meanwhile, in Figures 1 and 2, a boat support device is shown by the number (23), which functions to assure a safe storage of the boat (3) in a storage position, and is operated by handles (24) through the aid of ropes (25). Further, with the boat davit of this invention, the boat (3) can be fastened by means of rope stays (26), tied to the bow and stern areas of the boat, for an increased stable storage, as illustrated in Figure 1.

The following procedure is to be observed when lifting up or down a boat (3). In order to lower a boat (3), the rope stays (26) should be detached from the bow and stern before any other steps, and unlock the support device (23) by operation of handles (24) to lower to the position shown in broken lines. Then let out the lifting ropes (11) by the winch (2), and the boat (3) goes down together with the cradle (13) as illustrated in Figure 2. The cradle rollers (15) roll down along the arm (10), thence along the slide panel (20), and further along the side of the ship after passing the lower edge of the slide panel (20).

When the boat gets down into the water, the hanging ropes (4) slacken and can be taken off the hooks (5) of the boat (3). And for lifting up a boat into the storage position, steps in the reverse order are taken; fix the lower ends of hanging ropes (4), which are tied to the fixing blocks (14) of the cradle (13), to the hooks (5) of the boat, then wind up the lifting ropes (11) by means of the winch (2). The boat (3) starts to go up along the side of the ship together with the cradle (13), then along the slide panel (20) and the arm (10), the cradle (13) being guided by the side frames (22) of the slide panel (20). Then put the support device (23) against the side of the boat (3), and keep the ropes (26) in tension, when necessary, to store in the storage position. This operation of lifting the boat (3) up or down is achieved very smoothly through the aid of the rollers (15).

In this invention, therefore, it is possible to lower a boat while a ship is sailing, because the boat is lowered along the arm and the slide panel through the aid of the cradle. And the said operation does not involve a swing-out which has been a "must" in conventional boat davits, and can be achieved extremely simply and quickly only by letting out ropes. Furthermore, the boat davit of this invention has a dynamical advantage since it does not need a swing-out mechanism and the load breaks up considerably into the vector of the axle direction. Further, the single support arm required is so light in weight and the mechanism is so simple that a compact boat davit can be obtained.

In addition, the movement of a boat is stable, and safety is substantially secured as compared with the cases of conventional hanging methods because in this invention a boat is lowered together with the cradle along the arm, the slide panel, and then along the side of a ship.

What is more, according to this invention, this boat davit is technically superior to the conventional ones in that it increases safety remarkably, because a boat slides down on the slide panel stably without being dislocated from this slide panel even in severe pitching and rolling conditions.

Claims

1. A boat davit, which comprises a fixed boat support arm, lifting ropes which move through the aid of pulleys attached to the ends of the said arm to lift and lower a boat, a winch to operate the said ropes, and a cradle which is located on a side of the boat and moves along the arm through the operation of the said ropes, the ends of which are connected to the upper part of the said cradle, the said cradle being provided on its both sides a series of rollers which move along the said arm, the boat being hung from the upper part of the said cradle by two hanging ropes of a set length, each of which is detachably attached to the boat at its bow and stern areas.

2. A boat davit as claimed in claim 1 , wherein the afore-mentioned boat support arm is single, thereby to make the boat davit light and compact.

3. A boat davit as claimed in claim 1 , wherein it provides a slide panel slanting downward from an optional position of the afore-mentioned boat support arm for a boat to slide down on, the said slide panel being designed to be wider at lower positions.