US701049A - Ship's davit or boat-lowering device. - Google Patents

Description

No. 7U|,049. Patented May 27, I902.

' P. C. JOHNSON.

SHIPS OAVIT OB BOAT LOWEBING DEVICE.

(Application filed Apr. 13, 190L) 2 Shedts-Sheet I,

(No Model.)

N0. 70!,049. Patented May 27, I902.

P. C. JOHNSON. I SHIPS DAVIT 0R BOAT LOWERING DEVICE.

(Application filed Apr. 18, 1901.)

2 Sheets-Sheet 2.

(No Model.)

UNiTnn STATES PATENT OFFICE.

PETER C. JOHNSON, OF SEAFORTI-I, NEAR LIVERPOOL, ENGLAND.

SHIPS DAVIT OR BOAT-LOWERING DEVICE.

SPECIFICATION forming part of Letters Patent No. 701,049, dated y 1902- Application filed April 13, 1901. Serial No. 65,682. (No model.)

To all whom it may concern:

Be it known that 1, PETER CRERAR J OHN- SON, a subject of the King of England, and a resident of Halifax, Nova Scotia, Canada, at present residing at Cambridge road, Seaforth, near Liverpool, in the county of Lancaster, England, have invented certain new and useful Improvements in Ships Davits or Boat-Lowering Devices, (for which application for a patent has been made in England, No. l6,4=64,dated September 15, 1900,)of which the following is a specification.

This invention relates to ships davits or boat-lowering devices, and has for its object to provide a more efiicient and reliable arrangement than is at present available.

It is a matter of common knowledge that ships boats are never got out in times of disaster with the rapidity necessary for the saving of life. Even the time occupied in lowering the boats during boat-drill when the ship lies on an even keel in port would be much too long in most cases of actual emergency, as apart from the general excitement then prevailing there are unfavorable condi tions of weather and water, which considerably delay operations. For instance, all the boats on one side are rendered useless by a list on the ship, as apart from other circumstances the davits being out of the vertical necessitate the enormous labor of lifting the dead-weight of the boat and its load in swinging out the davits. Now by my invention I dispense with the axial rotation of the davits and provide an arrangement of davit or jib adapted to swing straight outward between suitable guides, thus also enabling both davits or jibs of a boat to be swung out simultaneously. By this means I not only obviate the excessive work before pointed out in turning the ordinary davits even with a slight list, but also the loss of time caused by hav ing to turn each davit successively to enable first the bow and then the stern of the boat to be swung out with an endwise swing to clear first one davit and then the other.

The invention will now be described with reference to the accompanying drawings, in which-- Figure 1 is a general view in perspective of a boat-lowering device constructed in accordance with my invention and showing, for instance, two boats lying endto end. Figs. 2 and 3 are end elevations showing a boat swung out and in, respectively. Figs. I and 5 are detail views of the means for laterally guiding the jib.

In carrying the invention into efiect Ihinge or pivotally mount a jib Avertically or approximately vertically at a suitable point on the ship and arrange suitable guides to retain it laterally, while leaving it free to swing straight outward through a suitable arc limited by chocks or stops. A form of lateral guide which I have designed consists of a davit-shaped arm B rigidly mounted, which is provided with a long slot O for the upper portion of the jib A to swing in. F repre sents stout pins adapted to be inserted into any of the holes G provided in the arm B to act as stops to limit to the desired extent the are through which the jib A may swing. This arm B is preferably built up of two similarly-curved angle-irons secured together with a sufficient space between them to receive the jib, as shown in cross-section in Fig. 4:, or the jib A may be made to slidingly embrace or engage the arm B-as shown, for instance, in Fig. 5. A straight form of jib is preferable, as shown. Suitable tackles, such as 1 2 3, are provided for swinging the jib in or out and such as 4 5 6 for lowering the boat, and I also provide a small winch D for oper ating the boat-tackle, although the same may be operated without, if desired. The fall from the boat-tackle should be carried over a block 6, at or nearthe base or pivotal point of the jib, so as not to interfere with the operation of throwing over the jib, while the rope from the jib-operating tackle may be carried over a block 3, provided at the end of the guiding-arm B on a strut E, which stiffens said arm. A further tackle 7 8 may also be provided to start the throwing over of the jib. In practice a pair of such jibs A may be provided for each boat; but the invention enables three jibs to suffice for'two boats lying end to end, as shown in Fig. 1, instead of the four davits usually necessary. For this purpose the center jib A is provided with attachments for two boat-tackles-that is, one for each of the two adjacent-lying boats. This will not interfere with the lowering of either boat separately or of both simultaneously. By this means if all the jibs A be so provided all or any desired number of boats may be adapted to be lowered simultaneously, double winches, as at D, being provided for each jib carrying two boattackles where the boats meet end to end. This reduction in the number of jibs A as well as the built-up form of the guiding-arm B considerably cheapens the cost of the arrangement, which will more than counterbalance the cost of providing small winches for each jib.

With my invention much fewer men are necessary, as only two men will be required at each jib to work the winch and j ib-tackle, the operation being very easy and reliable. All that is necessary is to first work the winches (where such is provided) to lift the boats off the chocks, then while holding fast the winches to slacken the jib-tackles and let the jibs A swing out until they bear on their stops F, and to then complete the lowering by again working the winches.

To facilitate the working of the Various tackles, I employ winches having a separate barrel for each tackle, but with the barrels mounted on a single operating-shaft on each winch, with means for throwing any barrel into or out of gear with the said operatingshaft of the winch. This is clearly shown in Fig. 1, from which it will be seen that by moving the shipper-forks I the pinions J, splined on the operating-shaft K, may be thrown into or out of gear with the barrels to be operated. L represent treadles for operatin g band-brakes on the winches to control the operation of lowering the boats. The tackle 7 8 of the jib is taken up on a drum of the winch in proportion as the tackle 1 2 3 of the jib is slackened, and vice versa.

By arranging the jibs A with a slight outward rake when in the upright position more or less allowance may be made for a list on the ship, thus obviating any additional lifting work in bad weather.

It will be understood that the invention is not limited to any particular details of construction.

I declare that what I claim is- I. In ships davits orboat-lowering devices, the combination of independently-movable hinged or pivotally-mounted jibs adapted to carry the boat suspending and raising and lowering tackle at their free ends, and to be swung straight in or out in a vertical plane, and stationary rigidly-mounted arms adapted to guide and retain the upper portions of said jibs against lateral movement, substantially as hereinbefore set forth.

2. A boat-lowering device comprising a plurality of independently-movable hinged or pivotally-mounted jibs, means for swinging said jibs straight in or out in a vertical plane, and boat suspending and raising and lowering tackle attached to the free ends of said jibs, the tackle for adjacent boat ends,where boats are located end to end, being carried by a single jib, for the purpose of reducing the number of jibs otherwise required, substantially as hereinbefore set forth.

3. In a boat-lowering device, the combination with a plurality of hinged or pivotallymounted jibs having boat-tackle attached to their free ends, and tackle for swinging said jibs in or out in a vertical plane, of winch mechanism adapted to operate the various tackles, substantially as hereinbefore set forth.

4. In a boat-lowering device, the combination with a plurality of hinged or pivotallymounted jibs having boat-tackle attached to their free ends, and tackle for swinging said jibs in or out in a vertical plane, of winch mechanism adapted to operate the various tackles, said Winch mechanism having inde pendent barrels, one for each tackle, mounted on a single operating-shaft, and means for throwing any one barrel into or out of gear with the operating -shaft-, substantially as hereinbefore set forth.

5. A boat-lowering device comprising a plurality of hinged or pivotally-mounted jibs adapted to be swung in or out in a vertical plane, fixed guiding-arms adapted to retain said jibs against lateral movement only, Winches having each a plurality of independent barrels mounted on a single operatingshaft, means for throwing any one barrel of a winch into or out of gear with the operatingshaft, boat suspending raising and lowering tackle attached to the free ends of said jibs, with the falls carried over tackle located at points near the axis of oscillation of said j ibs to related winch-barrels, rear struts adapted to stilfen the guiding-arms and j ib-operating tackle carried from the jibs over tackle near the base of the guiding-arms and over tackle on said struts to other independent but related winch-barrels, substantially as hereinbefore set forth.

In witness whereof I have hereunto signed my name, this 18th day of March, 1901, in the presence of two subscribing witnesses.

P. C. JOHNSON.

Witnesses:

G. O. DYMOND, H. L. DIXON.

IIO

Images