US2041817A

US2041817A - Ship's davit

Info

Publication number: US2041817A
Application number: US37208A
Authority: US
Inventors: Carr George William
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-09-01
Filing date: 1935-08-21
Publication date: 1936-05-26
Anticipated expiration: 1953-05-26

Description

May 26,1936. w CARR 2,041,817

YSHIPS DAVIT,

s Shets-Shet 1 Filed Aug. 21, 1955 Jvwwaw GEORGE WILLIAM CARR, W 7 Ways,

G W. CARR SHIPS DAVIT May 26, 1936.

Filed Aug. 21, 1935 3 Sheets-Shegt 2 FIG. 3.

Jmawmv GEORGE WILLIAM CARR,

@Mwum extends beyond the keel b Patented May 26, 1936 UNITED STATES PATENT OFFICE Application August 21, 1935,v Serial No. 37,208 In Great Britain September 1, 1934 7 Claims.

This invention relates to ships davits which have a, boat-supporting arm attached to the ship by a plurality ofv members hinged in succession, and has for its primary object the provision of an improved construction of davit capable of swinging outboard by gravity even against a considerable opposing list of the ship.

A further object. of my invention is the provision of a davit which can be so arranged that, by its outboard swing, it carries the boat from the deck on which it is stowed to a suitable loading position at a preferred and pre-arranged lower deck before the boat is lowered in relation to the davit arm, thus minimizing the risk of the boat being damaged or upset which has hitherto usually occurred during the passage of the boats past the upper two or three open decks of a ship, and also, especially on ships where a number of boats are lowered simultaneously, providing increased stability for the ship by reason that the deadweight of the boats is hung from a lower level and the disembarking passengers may be assembled on a lower deck than hitherto.

With these and other objects in view, as will become apparent from the following description, my invention consists in the combination and arrangement of members and parts as set out in the claims appended to this specification.

The accompanying drawings illustrate, by way of examples, davits in accordance with my invention. In the drawings,

Figure 1 is a side elevation showing the davit in its inboard position;

Figure 2 is a face elevation; and

Figure 3 is a similar view to Fig. 1 showing the davit in its outboard position.

Figures 4 and 5, Figures 6 and 7, Figures 8 and 9 and Figures 10 and 11 are similar views to Figs. 1 and 3 respectively to a smaller scale illustrating alternative arrangements.

Referring to Figs. 1 and 2 of the said drawings, in the example therein illustrated, the davit comprises a hollow U-shaped boat-supporting arm a formedof side plates a rigidly connected together I and spaced by interposed plates d The davit arm in its inboard position extends around the boat 1) adjacent to its end, said arm being on the inboard side thereof, and the outboard end a of the lower portion of said arm of the boat. At its outboard end, the davit arm is attachedby a pivot pin 0 to the outboard member d of a series of members (1 -01 which are hinged together in succession end to end by pins e trans- V to swing out by gravity when the verseto the direction The inboard member d of said series is rigidly attached by bolts d to a stationary support comprising a pair of close-spaced parallel curved channel-section beams f, one on each side of said 5 hinged members. The beams brackets f to a deck erection f to the deck 9 near the side g of the ship.

The side plates a of the davit arm are extended to form lugs 11 which lie within the and overlap the hinged members d d the plate a on the underside of the arm being 1 are attached by g and by brackets lugs a of the davit arm and coact with the undersides of the beams f. Straps 7' connect the pins h to pins is projecting from the side plates a said straps being spaced away from said platesand lying on the 20 outsides of the beams f and thus preventing any side sway of the davit arms.

The hinged members al -0Z comprise cast blocks having end faces m and m above and below their hinge pins ewhich coact to limit the 25 A davit is provided for supporting each end 35 of the boat I), theboat being suspended by means of a pulley q attached to the end of a rope 1' which passes over guide sheaves s on the davit arm a. and around a pivoted guide sheave s on the roof g of the deck structure 51 thepulleys of the two davits for each boat are led from their sheaves s to a controlling winch which, as it is of customary construction, I have not illustrated. The winch allows the ropes r of both davits to be payed out simultaneously so that 45 said davits swing out in unison.

The davit illustrated in Figs. 1 and 2 is designed ships deck is horizontal or its upward slope towards the side 9 of the ship does not exceed 30, in which position 50 the centre of gravity t of the boat 1) lies slightly on the outboard side of a vertical line passing through the pin e joining the members al and d? together. The tendency of the boat and davit,

or the davit alone, is thus to swing outboard.

in which the arm a swings.

beams f 10 Pins h forming stops 15 said arm, said 0 The ropes r from 4,0

When the rope r is allowed to run off the controlling winch, the members d -d turn in succession about their pivot pins e until the faces m of the members d -d abut, the movement of each member being through a small arc and suflicient to carry the centre of gravity t slightly beyond each pivot in succession. The release of the rope r and the consequent downward movement of the members d -d cause the pivot c of the davit arm a to move downwards and engage the rest p, the davit at the same time swinging about said pivot into its outboard position, which is illustrated in Fig. 3, and being brought to rest by the stops h engaging the underside of the beams In this position it will be seen that the. thrust of the arm a is transferred to the beams f, and the arm a is rigidly held in its outboard position. In the example illustrated in Figs. 1, 2 and 3, the boat is carried by the davit arm to a level adjacent to the upper edge of the ships side 9 Further paying out of the rope r lowers the boat relatively to the davit arm.

Figs. 4 and 5 illustrate an alternative construction wherein the davit arm a is of deeper curvature than in Figs. 1, 2 and 3, the stationary member al is attached directly to the side of the deck erection 9 instead of to beams f, the position of the stops it is raised, and laterally-projecting stops n are provided on each side of the arm a to coact with the upper face of the member d when the arm a is in its inboard position as shown in Fig. 4. In this arrangement, the outboard position of the davit arm carries the boat 1) adjacent to the upper edge of the ships side g at the edge of the deck 9 immediately below the boat deck g, the arm a being held in its outboard position by the engagement of the pivot c and stops h on opposite sides of boat-deck stanchions it provided one on each side of the arm a. The stop pin it extends through the arm a and, in addition to acting as a final stop against the stanchions u in the outboard position of the arm, also coacts with the upper face of the outboard member d as shown in Fig. 4 when the davit arm a is inboard to serve as an inboard stop in combination with the stops n Figs. 6 and '7 illustrate another alternative construction wherein the stationary member (1 is part of an upstanding bracket '0 on the boat deck 9. In this arrangement, the davit arm a is hinged to the outermost member d and has a face a which abuts against a face m on said member when the davit reaches its outboard position and holds the arm in this position as shown in Fig. '7. When the faces a and m abut, a swelling a on the arm (1 makes contact with the deck 9' and assists in supporting the davit in the outboard position. The example of Figs. 6 and '7 provides a simple construction suitable for cargo vessels and other ships where a promenade space with clear headroom, such as is provided by the examples of Figs. 1-3 and Figs. 4 and 5, is not required.

Figs. 8 and 9 illustrate a modification of the davit of Figs. 6 and 7 wherein hinged members Li -d are arranged between the beams I which support the boat deck g and are thus protected from the weather, the member d being rigidly connected to said beams. In this arrangement, the outboard end of the davit arm a is bent as shown and works through the space between the beams P. In the inboard position, the arm a rests in a bracket 12 on the deck; in the outboard position, the stop it engages upstanding projections 19 on the beams f and the boat is at a convenient level for the deck g immediately below the boat deck.

Figs. 10 and 11 illustrate a modification of the example shown in Figs. 8 and 9 wherein the bracket '0 is dispensed with and the side of the deck erection 9 supports the guide sheave In Figs. 10 and 11, the hinged members d d are disposed below the boat deck 9, the inboard member al being rigidly connected to the beams f supporting said deck, and the davit arm a is extended so that, when swinging into its outboard position, it carries the boat, to the level of the second deck g below the boat deck g. An additional hinged member d is provided to which the outboard end of the arm a is pivoted at a. By increasing the length of the members d -d and the upper portion of the arm a, the davit may, if desired, be adapted to carry the boat to a still lower level. In the outboard position shown in Fig. 11, the stop h abuts against the insides of the side frames to of the ship, and the projecting ends of the pivot c abut against the outside of said frames. Davits constructed according to Figs. 10 and 11 are particularly effective in minimizing the risk of the boat being damaged or upset during loading and, by reason of the low level of the loading position, increase the stability of the ship during disembarking of passengers.

In all the above examples, it will be seen that my improved davit has an arm hinged at the outboard end of its lower portion to the outboard member of a series of hinged members, the inboard member of which is attached to the ship, and that, in the outboard position, said arm and members form a bracket projecting from the structure of the ship the rigidity of which prevents dangerous swinging of the boat towards and away from the ships side. Thus the boat can be loaded with passengers and a favorable opportunity for lowering it into the sea safely awaited.

What I claim as my invention and desire to secure by Letters Patent is:-

1. A ships davit comprising a boat-supporting arm, the lower portion whereof, when said arm is inboard, extends in the outboard direction beneath the boat, a series of members positioned beneath said lower portion and hinged together in succession end to end, pivot means connecting the outboard member of said series to the outboard end of said lower portion, rigid connection means between the inboard member of said series and the structure of the ship, said hinged members progressively lowering said outboard end as the boat-supporting arm swings outboard, and means on said lower portion for directly transferring the thrust of said arm to the structure of the ship, said means becoming operative when said arm reaches its outboard position.

2. A ships davit comprising a boat-supporting arm, the lower portion whereof, when said arm is inboard, extends in the outboard direction beneath the boat, a series of members positioned beneath said lower portion and hinged together in succession end to end, pivot means connecting the outboard member of said series to the outboard end of said lower portion, rigid connection means between the inboard member of said series and the structure of the ship, said hinged members progressively lowering said outboard end as the boat-supporting arm swings outboard, and laterally-projecting stops on said lower portion for transferring the thrust of said arm to the structure of the ship, said stops becoming operaportion, a

tive when said arm reaches its outboard position.

3. A ships davit comprising a rigid boat-supporting arm of U-shape partially encircling the boat on the inboard side thereof and extending beneath said boat to the outboard side thereof, when said arm is inboard, means for suspending the boat from the upper end of said arm, a series of members positioned beneath the lower portion of said arm which lies beneath the boat, said series conforming to the shape of said lower portion and being hinged together in succession end -'to end, a pivot connecting the outboard member of said series to the outboard end of said lower rigid connection between the inboard member of said series and the structure of theship, said hinged members progressively lowering said outboard end as the boat-supporting arm swings outboard, tion for transferring the thrust of said arm to the structure of the ship, said means, becoming operative when said arm reaches its outboard position.

4. A ships davit comprising a rigid boat-supporting arm of U-shape partially encircling the boat on the inboard side thereof and extending beneath said boat to the outboard side thereof, when said arm is inboard, means for suspending the boat from the upper end of said arm, a series of members positioned beneath the lower portion of said arm which lies beneath the boat, said series conforming to the shape of said lower portion and being hinged together in succession end to end, a pivot connecting the outboard member of said series to the outboard end of said lower portion, a rigid connection between the inboard member of said series and the structure of the ship, said hinged members progressively lowering said outboard end as the boat-supporting arm swings outboard, and laterally-projecting stops on said lower portion for transferring the thrust of said arm to the structure of the ship, said stops becoming operative when said arm reaches its outboard position.

5. A ships davit comprising a rigid boat-supporting arm of U-shape partially encircling the boat on the inboard side thereof and extending beneath said boat to the outboard side thereof, when said arm is inboard, means for suspending 'the boat from the upper end of said arm, a series of members positioned beneath the lower portion of said arm which lies beneath the boat, said series conforming to the shape of said lower portion and being hinged together in succession end to end, a pivot connecting the outboard member of said series to the outboard end of said lower portion, close-spaced supporting beams on the ship, one beam on each side of said series, a rigid and means on said lower porconnection between the inboard member of said series and said supporting beams, said hinged members progressively lowering the outboard end of said boat-supporting arm as said arm swings outboard, and laterally-projecting stops on the lower portion of said arm which transfer the thrust of said arm to said beams when said arm reaches its outboard position.

6. A ships davit comprising a rigid boat-supporting arm of U-shape partially encircling the boat on the inboard side thereof and extending beneath said boat to the outboard side thereof, when said arm is inboard, means for suspending the boat from the upper end of said arm, a series of members positioned beneath the lower portion of said arm which lies beneath the boat said series conforming to the shape of said lower portion and being hinged together in succession end to end, a pivot connecting the outboard member of said series to the outboard end of said lower portion, close-spaced supporting beams on the ship, one beam on each side of said series, a rigid connection between the inboard member of said series and said supporting beams, a face on said rigid inboard member against which the boatsupporting arm abuts when inboard, said hinged members progressively lowering the outboard end of said boat-supporting arm as said arin swings outboard, and laterally-projecting stops on the reaches its outboard position.

7. A ships davit comprising a rigid boat-supporting arm of U-shape partially encircling the boat on the inboard side thereof and extending beneath said boat to the outboard side thereof, when said arm is inboard, means for suspending the boat from the upper end of said arm, a series of members positioned beneath the lower portion of said arm which lies beneath the boat, said series conforming to the shape of said lower portion and being hinged together in succession end to end, a pivot connecting the outboard member of said series to the outboard end of said lower portion, close-spaced supporting beams on the ship, one beam on each side of said series, a rigid connection between the inboard member of said series and said supporting beams, said hinged members progressively lowering the outboard end of said boat-supporting arm as said arm swings outboard, and laterally-projecting stops on the lower portion of said arm, a recessed rest rigidly connected to said beams, said stops engaging said rest and transferring the thrust of said arm to said beams when said arm reaches its outboard position.

GEORGE WILLIAM CARR.