US2141452A - Means for launching lifeboats - Google Patents

Description

A. P. scHAf 2,

MEANS FOR LAUNCHING LIFEBOATS Filed Nov 18, 1936 2 sheets-sheet 1 Dec. 27, 1938. A P, SCHAT 2,141,452

MEANS FOR LAUNCHING LIFEBOATS Filed Nov. 18, 1936 2 Sheets-Sheet 2 Patented Dec. 27, 1938 2,141,452 MEANS FOR LAUNCHING LIFEBOATS Ane Pieter Schat, Utrecht, Netherlands Application November 18, 1936, Serial No. 111,502

Claims.

This invention relates to ships davits and has for its object to provide simple and ready means for launching boats therefrom.

According to the invention, the lower end of 5 each davit arm is pivoted, by a horizontal and longitudinal pivot axis, to a carriage adapted to travel down an outwardly sloping track, the davit arm and the carriage being further interconnected by a member, which is hinged to the davit arm intermediate the foot and the head thereof and also hinged to the carriage a suitable distance inwardly of said pivot axis, so as to prevent the davit arm from swinging outwards beyond a predetermined angular distance.

Said member may, for instance, be a chain, or a rod pivoted to the carriage and having a pin and slot connection with the davit arm, or vice versa. Preferably, however, it is used in the form of a toggle joint lever, the one link of which is hinged to the davit arm and the other to the carriage in such a manner that said lever will be substantially stretched when the davit arm is fully swung out. With this construction, the toggle joint may be engaged by a guideway so formed that movement of the joint along the same during the outward movement of the carriage forces the davit arm to swing out.

Three convenient embodiments of the invention are described with reference to the drawings erewith, in which:

Fig. l is a view in elevation of the first embodiment as seen from one end of the boat, the latter being shown in its inboard position,

Fig. 2 is a view in elevation of part of said 35 embodiment as seen from the inboard side of the boat, and

Figs. 3 and 4 are views in elevation of the second and of the third embodiment, respectively, both as seen from one end of the boat.

It is to be understood that in Figs. 1, 3 and 4 the carriage with the davit arm and the element interconnecting both for arresting the said arm when fully swung out are shown both in the extreme inboard and in the extreme outboard positions. Like parts are designated by the same numerals throughout the figures.

In Figs. 1 and 2, the suitably curved davit arm designated by 5. The same is pivoted, by a horizontal pivot axis 5, to a carriage 1 arranged to run on an outwardly inclined track composed of two channels 8, 8 with their open sides facing each other. Said carriage l is provided at its inboard end with two'rollers 9, 9 and at its outboard end with two rollers ill, ill, all adapted to run upon the top faces of the bottom flanges of the channels 8, 8.

The rollers 553, it are mounted upon the pivot 6, about which the davit arm 5 is adapted to perform the required lufling movement, and the rollers 9, 9 are mounted on a common pin H, which also serves as the pivot of a link l2, the end of which is hinged as at it to a second link It pivoted as at id to the central portion of the davit arm. 5. The links H, it thus form the toggle joint lever referred to hereinbefore.

The boat H6 in its stowed position as shown in Fig. l is suspended from, a pulley block ll pivoted to the respective end of the boat and having pivoted thereto a slip-hook it, which is engaged by a hook-shaped member E9 of the davit head. In said position the boat is also supported by checks 2t, 2t secured to the davit arm 5.

The fall 22, by means of which said end of the boat can be lowered, starts from a winch drum 23, which is secured to a deck 2 t, runs over a pulley 25 loosely mounted on the pin H, and engages the inboard side of a pulley 26 rotatable about a stud pin 2! secured to the central part of the davit arm 5 whence it is led around a pulley 28 rotatable about a pin 29 supported by the davit head. From the pulley 28, it passes to and around the sheave it? of the pulley block i? and is reeved around a second pulley 3! on the pin 29, whence it is led to a cleat 32 secured to the davit arm 5.

In its stowed position, the boat is secured by a gripe 33, one end of which is fixed to a bolt of the davit arm 5, the other end being connected through a sliphook 35 and a short chain 35 to the tail M of a catch hook 38, which is pivoted as at 39 to the track 8, 8 and adapted to engage over the pivot pin ll of the roller t, 5 to retain the carriage l inboard.

It will be understood that the other end of the boat is suspended in a similar manner from the head of a second davit arm, and that its fall may be led back to a second drum of the winch 23, by means of which, therefore, both falls can be payed out and hauled in.

To launch the boat it, the gripe 33 is cast off by means of the slip-hook 35, whereby the catch hook 33 can be released. The carriage l is then retained solely by its fall 22. On paying out the fall, the davit arm 5 will first swing out about its pivot 6 until it is arrested by the toggle link lever ii, it, it and assumes the position 5', wherein the eye it still engages the hook it, and thereupon the carriage l, together with the davit arm ii and the boat it, goes down its track 8, s by gravity until reaching the extreme outboard end of the track, where it is arrested by a stop 43. This extreme outboard position of the davit arm 5 is indicated by 5".

In this position, a man in the boat releases the slip-hook is from the hook-shaped member 59, whereby the weight of the boat is taken up by the fall 22, so that further paying out of the fall simply lowers the boat.

To get the boat inboard, the fall is wound in, raising the boat until the slip-hook l8 engages the member l9, so that the boat is again directly suspended from the davit head, after which the carriage I is drawn up the track 8, 8 and the davit arm swung inboard. At the extreme inner end ofthe travel of" the carriage I, the catch hook 38 is re-engaged and the gripe 33 replaced.

When the vessel has a considerable list, the boat on the low side, when freely suspended from its falls with the davit arms swung out. at the lower ends of the tracks l8, l8, wouldbe spaced an excessive distance from, and thus be liable to be smashed against the ships side.

the carriage 1 to be provided with means whereby it can be locked in any position between the higher and the lower end of its track. This can be accomplished, for instance, by mounting the rollers l0, H] on a spindle having right and left handed screw thread, so that by turning said spindle in the proper direction the said rollers can be moved laterally away from each other and forced against the webs of the channels 8, thus preventing the carriage from going down.

In Fig, 3, the davit arm 5 is provided near its foot with a pivoted toe 4i having rollers 62 adapted to run upon the top faces of the top flanges of the channels 8, 8. As long as the rollers 42 engage the said topfaces, thedavit arm 5 is prevented from swinging about its pivot axis 6, since the toe 4! is prevented, by a suitable stop, to turn in clockwise direction. ther details of the installation shown in Fig. 3 are substantially similar to those shown in Fig. 1, so that they need not be described, Thus, when. the stowed boat 16 is to be launched and. the gripe 33 is cast off, paying out of the fall 22 will cause the carriage 1 to go down with the davit 5 in its original position relative thereto. Only if, near the lower end of the track, the toe 4| disengages the channels 8, 8 and to turn in anti-clockwise direction relative to the davit arm, the latter is free to swing out. This position of the davit is indicated by 5, whereas 5" shows the extreme outboard position. 7

In the modification shown in Fig. 4, the pivot l3 of the toggle joint is guided by a suitably curved slot 43 in a rigid plate 44 secured on top of the track 8, 8; the curvature of said slot being so that during the downward motion of the cariage I along its track the link i l of the toggle link lever gradually turns the davit arm 5 out ward relative to the carriage, and that the davit arm is fully swung out to assume its position 5" when the carriage l engages the stop 40 at th lower end of the track 8, 8.

What I claim is: r

1. In an installation for handling a lifeboat on board a vessel, the combination with a track arranged athwartships on the vessel and sloping down towards the water, of a carriage adapted to run on the track, a davit arm connected with its foot to the carriage so as to be capable of luffing movement relative thereto, and a linkage comprising pivotally connected members hinged to the davit arm intermediate the foot and the head thereof and also hinged to the carriage a suitable distance inwardly of said connection so as to prevent the 'davit' arm from lufiing outward beyond a predetermined angular distance.

2. In an installation for handling a lifeboat V on board a vessel, the combination with a track arranged athwartships on the vessel and sloping down towards the water, of a carriage adapted to run on the track, a davit arm having its foot In order to be able to reduce this distance to the very minimum under all circumstances, it is desirable for The fur- 7 axis arranged longitudinally of the vessel, and a toggle joint comprising connected links, an intermediate pivotal connection between the links of the toggle, said toggle being hinged to the davit arm intermediate the foot and the head thereof and also hinged to the carriage a suitable distance inwardly of said axis so as to prevent the davit arm from swinging about said axis outward beyond a predetermined angular distance and means to move the intermediate pivotal connection of the toggle relatively to the hinged connections of the latter with the davit arm and the carriage. i

3. In an installation for handling a lifeboat on board a vessel, the combination with a track arranged athwartships on the vessel and sloping down towards the water, 'of a carriage adapted to run on the track, a davit arm having its foot hinged to the carriage by a horizontal and longitudinal pivot axis, a toggle joint comprising connected links, an intermediate pivotal connection between the links of. the toggle, said toggle being hinged to the davit arm intermediate the foot and the head thereof and also hinged to the carriage a suitable distance inwardly of said axisso as to prevent the davit arm fromswinging about said axis outward beyond a predetermined angular distance', and a member having formed therein a guideway in non-parallel relation with the track and engaging the intermediate pivotal, connection of the toggle joint so as to force the davit arm to turn outward relative to the carriage when the carriage moves down on its track.

4. In an installation for handling a lifeboat on board a vessel, the combination with a track 7 arranged athwartships on the vessel and sloping down towards the water, of a carriage adapted to run on said track, a davit arm'conneoted with its foot to the carriage so as to be capable of lufing movement relative thereto and provided with a toe adapted when the davit arm assumes its inwardly swung position to run on the track so as to prevent the davit from lufling but to allow of such luffing movement when disengaging. the track near the lower end thereof, and a member hinged to the davit arm intermediate the foot and the head thereof and also hinged to the carriage a suitable distance inwardly of said connection so as to prevent the davit arm from lufiing outward beyond a predetermined angular distance. r

5. In an installation for handling a lifeboat on board a vessel, the combination with a track arranged athwartships on the vessel and sloping towards the water, of a carriage adapted to run on the track, a davit arm having its foot pivoted to the carriage by a. horizontal pivotal axis arranged longitudinally of the vessel, a toggle joint comprisingconnected links, an intermediate pivotal connection between the links

Images