US55053A - Improved apparatus for lowering shipsj boats - Google Patents

Description

`Nrrn STATESA PATENT irren@ IMPROVED APPARATUS FOR LOWERING SHIPS BOATS.

Specification forming part of Letters Patent No. 55,053, dated May 29, 1866.

To all 'whom 'it may concern:

Beit known that we, SAMUEL BROWN and LEON LEVEL, of San Francisco, county of San Francisco, and State of California, have invented a new and useful Improvement in Lowering Ships Boats; and we do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same.

The work of lowering a ships boat is doneordinarily by two men, one stationed at each davit, one lowering the bow of the boat and the other its stern end, and this requires care, so that the parties may act in concert and lower the boat evenly, and the operation is not performed with that readiness and facility that is desirable in many cases, such as lowering a boat in a rough sea or when getting a boat down in a hurry for any purpose what-i ever.

The object of this invention is -to provide a means whereby both falls or hauling parts `of the tackles may be under control of and be operated by a single person, instead of two persons, as heretofore, and in such a manner that a friction brake or device may be employed to lower the boat fast or slow at the will of the operator.

Our invention consists in a double leadingblock, through which both falls lead on their way to the davits, the block having an extra set of sheaves, which are free to be carried to and from the real sheaves by the agency of a braking-lever, so that the eXtra sheaves may be pressed upon the real sheaves and the two falls be pressed firmly between the two sets of sheaves, insuring uniformity of action in lowering the boat and placing the friction of the parts under such control that the operation may be conducted with much celerity or with deliberation, as desired.

Having thus described the nature of our invention, we will proceed tov describe its construction and operation.

Figure lin the accompanying drawings is a 'front view, and Fig. 2 is a side view, of our iinprovement.

Similar letters of reference in the different iigures indicate corresponding parts.

A is the shell of the block. K K is its iron strap. It has two sheaves, c c, which are both keyed onto the pin or pivot b rmly, so that both of the sheaves a a must always move or rotate with the same velocity, and it has also a second set of sheaves, c c, which are xed on the pin d d, the ends of which work vertically4 in slots J, Fig. 2, in the iron block-strap K. The ends of the sheave-pin d are suspended in an iron strap, H, Fig. 1, which forks and runs down upon each side of the sheaves, so as to straddle the same, as shown by the two parts h h of the fork, Fig. 1, and by the dotted outline h, Fig. 2. The upper part of this suspending-strap H h h connects with a lever, Ff, which is pivoted onto the top of the strap K by a pivot, g. The red lines e e represent the fallsof the davit-tackle.

Its operation is as follows: The block A is secured to the rail of the ship, or in any favorable location, in a vertical position, by the strap at the lower end, I, and as lsoon as the boatis hoisted up the falls e c are rove through A, as shown by Fig. l, and then the falls are belayed or secured in the usual manner to pins in the rear of A, and then the device is always ready for immediate use when the boat is to be lowered and no time is lost in preparation.

In lowering a boat by the aid of this block one man steps forward and presses down upon the lever F, and makes the friction of the sheaves and running parts of the block so.

great that the falls are cast loose entirely in the rear of the block A, and the said braking: block A then has the whole strain of holding the falls, and by removing a part of the pressure from the braking-lever F the boat is run down evenly and at any velocity desirable. The two sets of sheaves a c being both secured rigidly to the pins b d, the same length of falls c e must run through on each set of sheaves a, and c.

The falls, in passing from the braking-block A to the davits, must necessarily have a sharp divergin g angle after leaving the block A, and an ordinary leading chock or guide is used to make the falls leave the sheaves of the block A squarely and fair.

By these means the management of both tackle-falls is placed under the control of a single person, so that a boat may be lowered with less care and more expeditionally than heretofore.

Having thus described our invention, what secured rigidly to their pins b d substantially we claim as new, and desire to secure by Letin the manner and for the purpose set forth.

ters Patent', is- The above specification of our invention Abraking-biookforrunningouteven lengths signed by us this 29th day of March, 1866.

of two or more ropes, having an extra set of SAMUEL BROWN.

sheaves, c, which are capable of being moved Witnesses: LEON LEVEL.

to and from the rea-1 sheaves a by a braking- M. M. LIVINGSTON,

lever, F, the different sets a c Vof sheaves being ALEX. F. ROBERTS.

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