US1520087A - Davit - Google Patents

Description

Dec. 23, 1924. 1,520,087 A. P. SCHAT a DAVI '1 Filed Dec. 26. 1919 2 Sheets-Sheet 1 INVENTOR.

A. P. SCHAT DAVIT Filed Dec. 26. 1919 2 Sheets-Sheet 2 I N VEN TOR.

A TTORNE Y.

Patented Dec. 23, 1924,

UNITED STATES ANE P. SCI-IA'I, OF U'IEECHT, NETHERLANDS.

DAVIT.

Application filed December 26, 1919. Serial No. 347,637.

To all whom it may concern:

Be it known that I, Alva P. SoHA'r, a citizen of the Kingdom of the Netherlands, residing at Utrecht, and Kingdom of the Netherlands, have invented certain new and useful Improvements in Davits, of which the following is a specification.

My invention relates to ships" davits, and more particularly to that class of davits which is adapted to swing lifeboats overboard automatically.

My objectis to provide a pair of automatic rotatable davits located at the outer side of the boat, and adapted to allow one end of the boat to swing out in advance of the other, without either end contacting with the davits, whereby a boat longer than the distance between the davits may be used.

Another object is to provide a pair of davits for a lifeboat, with one or both davits inclined and otherwise so arranged and constructed that one of the davits will operate by gravity in advance of the other and will move through a considerable angle before the other has moved a material distance from its starting point, thereby prolonging the period of action of the davits in swmging a boat overboard, in order to give the slowest possible movement of the boat with any given inclination of davit.

A further object is to provide a pair of davits so constructed and arranged that both davits may be made to act automatically to swing a lifeboat overboard, or that only one of the davits will. act automatically, but in doing so will also operate the other davit.

Other objects will appear in the subjoined description, reference being had to the accompanying drawings, in which F igs. 1, 2, and 3, illustrate diagrammatically an embodiment of the invention in a side elevational view, an end view, and a plan view, respectively.

Fig. 4- illustrates a series of davits mounted in stationary frames secured on ships deck, with the axes of rotation of the davits having permanent inclination outward, each frame here serving as a support for two adjacent davits.

Figs. 5 and 6, illustrate, on an enlarged scale, said double frame in side elevation and plan View respectively, together with the brake mechanism employed with the davits.

The lifeboat 1 is suspended by means of tackles 2, 3, from rota-table davits 4;, 5, supported by cup bearings preferably mounted on the side of the ship. The davit 4 (see Fig. 2) has its axis of rotation disposed at a considerable inclination outwardly, the axis of davit 5 being vertical, assuming the ship to lie normally in horizontal position on the water.

The distance between said da-vits is less than the length. between the boats.

hen the boat and the davits 4-, 5, are in the position shown in full lines, the boat swings below the davit heads after it is cleared of the chocks. Owing to this motion, the point at which the tackle 2 is attached to the boat descends, while that of the tackle 3 remains at substantially the same level. Under the action of gravity the boat will therefore move to the right hand side, that is to say, towards the davit 5, whereby the boat will assume the position 1 shown in dotted lines. At the same time, however, the davit t commences to swing around about its axis of rotation, whereby the boat clearing this davit, will move to the further position 1*. Up to this point the davit 5 has not turned through any appreciable angle, but from-this position onward, the system moves outward by gravity, i. e., the davit 4 with the boat suspended therefrom exerts a pull on the davit 5, whereby the rear end. of the boat moves clear of davit 5 until the boat finally reaches its extreme outboard position 1.

In order to facilitate the inboard movement of the boat when it is desired to stow it upon its chocks, the davit 4 is preferably coupled with means by which its inclination toward the side of the ship may be varied, and allowing the davit to be set with its axis of rotation inclining inwardly, saidmeans being diagra-mmatically shown in Fig. 2, and consisting of a horizontal pipe 6 mounted for longitudinal movement in a post 6*, said pipe being provided at its outer end with bifurcations 6 (see Figs. 1 and 2) which are pivotally connected to the opposite sides of a collar 6" carried by the davit, and within which the davit rotates, while at its inner end this pipe is internally threaded to receive a cooperating threaded bar 6 which is rotated by a hand wheel 6 supported in a post 6, whereby the internally threaded pipe 6 and the threaded bar 6 form means for adjusting the davit 4 to outward or inward inclination.

Means for regulating the inclination of the davit are not claimed broadly herein, since such means are described and claimed in the specification of my copending application No. 286,018.

As it should be possible to swing the boat outboard in case of the ship having a heavy list, davit 5 may also be provided with means allowing its axis of rotation to be disposed at varying inclinations relatively to the ships side, so that one davit may always be given a true vertical position while the other has its axis of rotation suitably inclined outwards.

It should be understood that I may also mount both davits with their axes of rotation under equal or unequal inclinations outwardly. In order that the boat in this case may be swung outboard it may be necessary to initially prevent the one davit from rotating, for instance by brake means, and to release it after the other davit has swung outboard about its axis.

In the arrangement shown in Figs. 1 to 3, the lifeboat would collide with both davits if while extending in longitudinal parallelism with the ship it had freedom to move laterally outward in a line at right angles to said direction. The arrangement may however be such that only one davit assumes the inclined position, the other being cleared when the boat moves as stated above, (see Fig.

According to Fig. at, all the davits are mounted in stationaryframes 7 secured on deck, so that their axes of rotation have permanent inclination outwards, each frame here serving for supporting two adjacent davits. Figs. 5 and 6 illustrate the said double frame in side elevation and in plan view respectively.

Each davit is provided with a brake disc 8 having a brake band 9 thereon adapted to be tightened and released by a screw actuated by a hand wheel 11.

It should be noticed that with the arrangement shown in Fig. 4 it is not strictly necessary to initially prevent one davit from rotating when it is desired to swing the boat outboard in the manner specified, since in the outset, one end of each boat is free to move laterally outward and the other is prevented from doing so by one of the frames till the former end has advanced a certain distance.

As a matter of course, the arrangements described may be combined and varied in many respects without departing from the underlying inventive idea. All the arrangements and variations, however, have the common feature that they allow the boats to be placed on deck with very small interspacing, and yet permit them to be swung outboard automatically, the movement being controlled, if desired, by simply tightening or releasing suitable braking mechanism.

It may also be pointed out that with inclined davits, ditliculty is often experienced in preventing the boats from moving out too suddenly, especially if the boat has an unusually heavy load, or if the ship has a list in the direction of the outboard movement.

l Vith my present arrangement in which one davit moves in advance of the other, the davits, to a certain extent, operate one at a time, so that in their outward movement the advance davit has reached and passed the point at which it moves with the greatest force before the other davit has reached the corresponding position in its outward movement. Hence, the force which causes the davits to rotate is more evenly distributed and extends over a longer period of time than if each davit exercised its maximum power of rotation at the same time.

Again it has been found that inclined davits have a tendency to swing out so sud denly overboard that it is impossible to operate the brake mechanism quick enough to catch the davits, so to speak, before they are already out.

lVith my present construction it will be seen that by applying a brake to the tardy davit, it will be a very easy matter to have the system under control of the brake before the boat has moved far outboard. Moreover, even if the lock be applied to the advance davit, the fact that the outward movement of, the boat is distributed over a longer period of time, will give better opportunity to operate the brake, than in any case where both davits move out together.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a device of the character described, a pair of rotatable davits arranged to swing a lifeboat overboard one end in advance of the other, one of said davits being arranged to swing outwardly by gravity to cause it to act automatically, and the other davit being free to rotate but not adapted within itself to rotate by gravity.

2. In a device of the character described, a pair of rotatable davits arranged at the outer side of a lifeboat to swing out over the water, one of said davits being arranged to swing outwardly by gravity to render the same automatic in its outward movement, and the other davit being free to rotate but not adapted within itself to rotate by gravity, said gravity-actuated davit being arranged to travel ahead of the other davit as the two go outboard.

3. In a device of the character described, a pair of rotatable davits arranged at the outer side of a lifeboat, said boat being suspended therefrom and connecting the two davits together, said davits being disconnected from each other except by the suspended boat, one of the davits being arranged to swing outwardly by gravity to render it automatic in its outboard move ment, and the other davit being free to 1'0- tate, but not adapted within itself to rotate by gravity, the automatic davit traveling in advance of the other davit as the two go outboard; and means for regulating the automatic action of the gravity davit.

4. In a device of the character described, a pair of rotatable davits for swinging a lifeboat overboard, said davits being arranged one adjacent each end of the boat, one of said davits having its axis of rotation normally inclined to cause the davit to swing by gravity to its lowermost position to render the davit automatic, and the other davit having its axis of rotation nor mally vertical and therefore not adapted within itself for automatic rotation; a flexible connection between each davit and its respective end of the boat, whereby to utilize the boat and said flexible connections to form a yielding connection between the two davits to control the outward rotation of both davits by the automatic davit; and means for regulating the automatic action of the gravity davit.

5. In a device of the character described, a pair of rotatable davits for swinging loads overboard, one of said davits being adapted to rotate by gravity and the other davit not adapted to rotate by gravity; means for yieldingly connecting said davits together, whereby the tendency of the one davit to rotate by gravity is yieldingly communicated to the other davit which of itself does not tend to rotate by gravity; and means for regulating the automatic action of the gravity davit.

6. In a device of the character described, a pair of rotatable davits arranged at the outer side of a lifeboat closer to each other than the length of the boat, one of said davits having its axis of rotation normally inclined outwardly to cause the davit to swing overboard by gravity, and the other davit being vertical andnot adapted to be swun g out by gravity; and means for varying the degree of axial inclination of the inclined davit and for changing the direction of its inclination from an outward in clination to an inward.

7. In a device of the character described, a pair of rotatable davits arranged at the outer side of a lifeboat and spaced apart a distance less than the length of the boat, one of said davits being vertical and not adapted to rotate by gravity, and the other being inclined outwardly to cause it to retate overboard by gravity and having its jib extending inwardly diagonally across the boat in a direction to cause it to rotate outwardly ahead of the vertical davit when the boat is released from its chocks and hangs suspended from the davits, whereby to cause said inclined davit in its initial outward movement to swing the boat longitudinally toward the vertical davit, to cause the end of the boat supported by the inclined davit to clear said davit, and whereby to also retard the outward movement of the vertical davit till the end of the boat supported by the inclined davit has moved outwardly past its davit; and means for varying the inclination of the inclined davit.

In testimony whereof I aflix my signature.

AYNE P. SCHAT.

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