US1090588A - Ship's davit or the like. - Google Patents

Description

H. N. WYLIE.

SHIPS DAVIT OR THE LIKE.

APPLIOATION FILED SEPT. 16, 1913. 1,090,588, Patented Mar. 17, 1914.

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H. N. WYLIE.

SHIPS DAVIT OR THE LIKE.

APPLICATION FILED SEPT.16,1913.

1,090,588 Patented Mar. 17, 1914.

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sans air HAMILTON NEIL WYLIE, or EDINBURGH,

NT @FFTQE SCOTLAND, ASSl'GNOfi TO BABGOCK dz WILCOX LIMITED, OF LONDON, ENGLAND.

SHIPS DAVI'I OR THE LIKE.

Specification of Letters Patent. Patgntgd Mar, 1'? 11914 Application filed September 16, 1913. Serial No. 789,893.

davits and other apparatus for transporting boats or other loads, and has for its pr1-. mary object to provide an improved apparatus suitable for use on board a ship under all conditions by means of which the load may be carried a relatively great distance to either side of the supporting frame of the apparatus or past the same from one side to the other so that the boat or other load can be carried from a position well inboard to a position well outboard preparatory to lowering, the path in which the boat or other load is carried being horizontal or approximately horizontal so that a moderate power suffices to move the boat or other load which is maintained at a conven ient height above the ships deck or other surface.

In the accompanying drawings which illustrate the invention, Figures 1 and 2 are diagrammatic views; and Figs. 3 and 4: are end and side views respectively of a preferred form of apparatus for transporting ships boats in which a pair of davits is used to transport the boats, one davit supporting each end of a boat.

Referring to the drawings, J represents jibs each pivoted at its lower end on trunnions 0 so as to swing in a vertical plane. Mounted on said jibs is a shaft B, substantially parallel with the 'trunnions 0. Secured to the shaft are levers L adapted to support the load, and frames or headpieces H. To each of said frames or headpieces H are fixed curved rests G and Ii each substantially of the form described in the specification of Letters Patent No. 970,773. Secured to each headpiece are flexible stays E and F which are adapted to pass around the rests G and K, respectively, and which are anchored to the foundation frame at the points X and Y. a

When the jibs J are swung toward the points Y, the stays E cause the lever L to swing outward, the rests G regulating the rate of the swinging movement of the levers so that the load is carried in a path which is characteristic of the curve G, and which is preferably a straight line inclining upward at the outer end.

To prevent the stays on the side toward e J .whlch the ]llOS are swung from becoming slack, the curves G and K are extended, as at M and N, respectively, so that the stays toward .which the jibs are swung are taken up in such measure that they are maintained substantially taut. The levers L are thus firmly stayed against movement in either direction when the jibs J are held stationary, so that the suspended load is taken up by both sets of stays.

For operating the jibs, ropes or chains 6 and f are attached to each headpiece and adapted to pass around additional oppositely disposedcurved rests m and a, respectviely, (Fig. 2). The ropes e and f pass from their respective curved rests m and at around pulleys A and C, respectively, and are wound in opposite directions around the drum D. When, for example, the drum D is rotated so as to wind up the rope f, the rope e is simultaneously unwound. Owing to the contour of the rest n the leverage with which the rope f acts on the headpiece is varied and is thus regulated, the leverage being preferably increased in positions of large outreach. An extension g of the rest m serves to wind up the rope e as it is paid out by the drum D in such measure that the rope e is maintained substantially taut. The rest a is provided with an extension 7r; similar to the extension 9 the extension 7; serving to take up the slack of the rope f when the drum D is rotated in the opposite direction. The winding up of the rope 6 when the jib is in the position shown in Fig. 2 causes the stay E to be wound on to the rest G; consequently the stay E furnishes the necessary reaction for the rope e, w1th the result that the jib, the lever and the load are moved toward the supporting frame- In the case of the apparatus illustrated in Figs. 3 and 4, the load (in the instance trunnions O.

The length of the jib J and that of the lever L are determined to suit the outreach and headroom required.

The contour of the rests G and K and M and N is determined as hereinafter explained with reference to Fig. 1 of the drawings.

To determine the contour of the rest G, the locus of the pulley P is first found, this locus being determined so that the path of a load carried on the hoisting line is hori- Zontal, account being taken of the fact that the hoisting line moves to some extent over the pulley P as the jib J is inclined.

The position of the lever L for each position of the jib having been ascertained, the tangent to the curve G for each position of; the jib J and lever L is drawn on the headpiece, and the curve thus outlined is drawn down.

To find the tangent to the curve Gr in any position of the lever L and jib J, horizontal lines are drawn through B and O, and on these lines are laid off BU and Oi representing to the same scale, respectively, the moment about B of the tension in all parts of the hoisting line acting on the lever and the moment about 0 of the tension in all parts of the hoisting line acting on the jib. V is the intersection of the straight lines z'U and 013 produced, and VX is the tangent to the curve G requiredf The form of the curve K is determined in the same manner.

In some cases it is advantageous that the load should rise toward each end of its range of movement. To provide for this, the curves are first determined so as to obtain a straight line motion with an assumed length of lever. If the length of the lever be increased, the load will rise at the ends of its path.

The form of the extensions M and N is determined in a manner strictly analogous to that followed in determining the curves G and K. The line VY is the tangent to the curve N for the position shown in Fig. 1, and if the proper tangents be drawn on the headpiece for each of a number of positions of the jib J and lever L the outline of th curve N is obtained.

The form of the curves m, n, g, is is determined as hereinafter explained with reference to Fig. 2 of the drawings.

For the sake of simplicity, in the follow ing explanation the ratio of the length VB to the length V0 is designated by the letter 00. In Fig. 2 a and b are the distances from O and B, respectively, to the line 6;

and 0 and d are the distances from O and B, respectively, to the line f. The moment about 0 of a unit tension in the line The rate at which the rope e is wound on the drum D and the rate at which the rope f is unwound, and vice versa, are preferably the same. Assuming this condition. the curve 70 is determined so that the distance in all positions of the lever L and the jib J on the side of, the vertical position of the jib adjacent to the pulley C. The curve 9 is determined so that in all positions of the lever L and jib J on the side of the vertical position of the jib adjacent to the pulley A.

Having now described'my invention what I claim and desire to secure by Letters Patent of the United States is i 1. The combination with a jib, of a lever having a swivel connection with said jib, a plurality of curved rests adapted to partici pate in the swiveling movements of said lever, and flexible means engaging said curved rests.

2. The combination with a jib adapted'to swing in a single plane, of a lever having a swivel connection with said jib, a group of curved rests adapted to participate in'the swiveling movements of said lever, flexible means engaging said curved rests, a second group of curved rests adapted to participate in the swiveling movements of said lever,

and flexible means engaging said second group of curved rests.

3. The combination with a jib, of a lever having a swivel connection with said jib, a pair of curved rests formed with extensions, said rests and extensions adapted to participate in the swivelingmovements of the lever, and flexible means in engagement with said rest-s and extensions.

4. The combination with a jib adapted to swing in a single plane, of a levcr having a 189 swivel connection with said jib, a pair of curved rests adapted to participate in the swiveling movements of said lever, flexible means engaging said curved rests, a second pair of curved rests and extensions adapted to participate in the swiveling movements of said lever, and flexible means engaging said second pair of curved rests and extensions.

5. The combination with a jib adapted to swing in a sin le plane, of a lever having a swivel connection with said jib, a pair of curved rests and extensions adapted to participate in the swiveling movements of said lever, flexible means engaging said curved rests and extensions, a second pair of curved rests and extensions adapted to participate in the swiveling movements of said lever, and flexible means engaging said second pair of curved rests and extensions.

6. The combination with a jib, of a lever fulcrumed to said jib, curved rests formed with extensions, said rests and extensions adapted to participate in the movements of the lever on its fulcrum, the distance of the operative faces of said rests and extensions from said fulcrum increasing toward their extremities, and flexible means engaging said rests and extensions.

7. The combination with a jib, of a lever fulcrumed to said jib, pairs of curved rests adapted to participate in the movements of the lever on its fulcrum, and flexible means in engagement with said curved rests and adapted in conjunction therewith to control the swinging movements of the jib and the lever, said rests being so contoured as to insure tautness of said flexible means in different positions of the jib.

8. The combination with two jibs adapted to swing in parallel planes, of a shaft mounted on said jibs, load-carrying levers secured to said shaft, pairs of curved rests also secured to said shaft, and flexible means engaging said rests and adapted to control the swinging movements of the jibs and of the levers.

9. The combination with two jibs adapted to swing in vertical planes, of a horizontal shaft mounted on said jibs, load-carrying levers secured to said shaft, curved rests also secured to said shaft, and flexible means engaging said rests and adapted to control the swinging movements of the jibs and of the levers.

10. The combination with two jibs adapted to swing in parallel planes, of a shaft mounted on said jibs, load-carrying levers secured to said shaft, four pairs of curved rests fixed to said shaft, and flexible means engaging said rests and adapted to control the swinging movements of the jibs and of the levers.

11. The combination with two jibs adapt ed to swing in parallel planes, of a shaft mounted on said j ibs, load-carrying levers secured to said shaft, four pairs of curved rests fixed to said shaft, four stays each anchored at one end and each secured at its opposite end to a curved rest, each stay enveloping its corresponding rest, ropes engaging the four remaining rests, and means for actuating said ropes.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HAMILTON NEIL WVYLIE.

WVitnesses:

WALLACE CRANSTON FAIRWEATHER, DANIEL MoALLAN.

(topics of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. 0.

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