US1024507A - Boat's davit and the raising and lowering gear therefor. - Google Patents

Description

J. GRAHAM.

BOATS DAVIT AND THE RAISING AND LOWEBING GEAR THEREFOR.

APPLICATION FILED MAY 31, 1910. I 1,024,507, Patented Apr. 30, 1912.

3 SHEBTSSHEET l.

J. GRAHAM.

BOATS DAVIT AND THE RAISING AND LOWEBING GEAR THEREFOR.

APPLIUATION FILED MAY 31, 1910.

1,024,507. Patented Apr. 30, 1912' 3 SHEETSSHEET 2.

Y J. GRAHAM. BOAT'S DAVIT AND THE RAISING AND LOWERING GEAR THEREFOR.

APPLICATION FILED MAY 31, 1910.

Patented Apr. 30, 1912.

3 SHEETSSHEET 3.

mine-5.56.5:

UNITED STATES PATENT OFFICE.

JOHN GRAHAM, O-F GLASGOW, SCOTLAND.

BOATS DAVIT AND THE RAISING AND LOWERING GEAR THEREFOR.

Specification of Letters Patent.

Patented Apr. 30, 1912.

Application filed May 31, 1910. Serial No. 564,199.

To all whom it may concern:

Be it known that I, JOHN GRAHAM, a subject of the King of Great Britain, residing at Glasgow, Scotland, have invented certain new and useful Improvements in and Connected with Boats Davits and the Raising and Lowering Gear Therefor, of which the following is a specification.

This invention relates to boats davits and to the raising and lowering gear therefor. Under this invention there is provided a single davit, which turns about a vertical axis, and from which the boat is slung centrally by a single rope, the winding gear for lowering and raising the boat being se cured to and carried by the davit, and means being provided for automatically locking the davit in the outboard lowering position and also in the inboard position. Further, an automatically acting braking arrangemnt is provided for arresting the fall of the boat should the operators leave or be washed away from their posts during the raising of the boat. Other improvements are also provided in connection with the davit.

In order that the invention may be clearly understood I have hereunto appended explanatory drawings which show, by way of example, one mode of carrying out the invention.

On the drawings :-Figure 1 is a side view of the single davit and showing the boat raised off the chocks ready for lowering. Fig. 2 is an enlarged view showing the locking gear. Fig. 3 is a vertical section of the lower end of the davit. Fig. 4 is a plan view of the locking mechanism of the davit. Fig. 5 is a vertical section of the same. Fig. 6 is a side view of the brake gear. Fig. 7 is a vertical section thereof.

In carrying out the invention the davit a is preferably made with a pair of side cheeks b which may be partially or wholly closed at the front and receive, therebetween, the winding gear by means of which the boat is raised and lowered, the suspension rope 0 being passed over pulleys c in the davit a and around a pulley 0 The boat raising and lowering gear consists of a winding drum (Z which is fixed on a shaft 6 and is capable of being operated, through reducing gear wheels cl ,,by means of a pair of crank handles (Z and pinions and freely mounted concentric to the intermediate shaft 6 of one of the gear wheels (Z is an internally toothed wheel or ring 6 (see Figs. 6 and 7') having ratchet or inclined teeth adapted to be engaged by pawls f freely pivoted on the face of a disk or wheel f which is keyed on the said intermediate shaft 6. Located around the outer periphery of the said free wheel or ring 6 is a hand brake 9 one end of which is secured, at 9 to the fixed frame or casing of the gear, while the opposite end thereof is provided with a nut or internally screwed socket portion 9 with which engages a screw threaded spindle 9 having, on the outer end thereof, a hand wheel g by means of which the brake 9 may be tightened around the wheel or ring 6 or released therefrom as desired. The band 9 is provided with a friction strap or a series of friction blocks 9. When it is desired to lower the boat the band brake g is released from the free wheel 6 by means of the hand wheel g thereby allowing the drum d and free wheel 6 to rotate and pay out the rope 0 as the boatdescends, and,

when it is desired to hoist the boat the band brake g is tightened around the free wheel 6 by means of the hand wheel 9 the drum (Z being rotated by means of the crank handles cl and pinions and gear wheels 0?. As the drum (Z rotates the'disk or wheel f is also rotated and the pawls f thereon. run over the teeth of the free wheel 6 but, should the operators bewashed away from, or leave their posts during the hoisting op eration the back motion of the disk f will cause the pawls f to engage the wheel 6 thereby arresting the rotation of the disk or wheel f and drum d and holding the boat.

For automatically locking the davit in place there is secured thereon a projection h which moves over the face of the ring 7&1 through which the davit is passed and provided on this ring 71,1 are two stop blocks or projections b k by means of which the movement of the davit a is arrested the hole k in the projection 72, coinciding with one or other of the holes if in the-ring h when the davit is so arrested. In engagement with the hole 71; in the projection h and capable 'of dropping by gravity into engagement with one of the said holes 7?, is the locking pin 6 which is connected by means of the rod 2' with a pivoted hand lever i in such manner that it may tall automatically into engagement with one of: the holes it, and may be raised out of engagement by means of the hand lever 2' The davit a made at the foot thereof with a socket within which is a spring j whose one end is secured by a project-ion to the socket and whose other end is secured to a fixed base part extending into the socket j and fitting tightly therein in such manner as to prevent the admission of water to the spring. Extending upward from the base portion is a central pin whose upper end is fitted into a bearing hole made in the upper end of the socket j and located between the upper end of this pin 70 and the davit is a washer 71: for taking up wear. The torsional action of the spring 3' checks and resists the movement of the davit as itswings thereby preventing the snug h violent-1y jarring against the stops (b 72, which latter may also, if desired, be provided with rubber cushions.

The pulley block 0 is provided, for engagement with the sling m, with a hook at having a pivoted nose part a which, on the load being taken oil the hook, automatically opens and so disengages the hook, the pivoted nose part a being held closed, when so desired, by means of a chain or the like M. In order to prevent the boat swinging outward, under centrifugal force, on the davit being turned around, the hook part 0 is pro vided, with which the gunwale of the boat can be brought into engagement and then held by tightening up the rope 0.

If so desired the hoisting gear may, instead o't being operated by hand, be operated by means of steam, hydraulic, electric or other power, a suitable motor being mounted on, or being located in any convenient position clear of the davit. Instead of the spring 7" at the foot of the davit, means, consisting of pawl and ratchet or equivalent mechanism, might, if desired, be provided for preventing the davit swinging backward when being moved from the inboard to the outboard position and vice versa. The davit may, if desired, be arranged between two boats so that, as desired, one or other of the boats can be manipulated.

Having now fully described my invention what I claim and desire to secure by Letters Patent is 1. A ships davit comprising, in combination, a single davit turning upon a vertical axis and from which the boat is slung centrally by a single rope, winding gear on the davit for lowering and raising the boat, means for locking the davit in the outmost lowering position and also in the inboard position and spring means at the bottom of the davit for checking the movement of the davit.

2. A ships davit comprising, in combination, a single davit turning upon a vertical axis and from which the boat is slung centrally by a single rope, winding gear on the davit for lowering and raising the boat, means for locking the davit in the outmost lowering position and also in the inboard position, a socket in the bottom of the davit and spring means in the socket for checking the movement of the davit.

3. A ships davit comprising, in combination, a single davit turning upon a vertical axis and from which the boat is slung centrally by a single rope, winding gear on the davit for lowering and raising the boat, means for locking the davit in the outmost lowering position and also in the inboard position, a socket in the bottom of the davit, a fixed base with projecting pin entering said socket and a spring interposed between the base and the socket so as to check the movement of the davit.

4. A ships davit comprising, in combination, a single davit turning upon a vertical axis and from which the boat is slung centrally by a single rope, winding gear on the davit for lowering and raising the boat, means for automatically locking the davit in the outmost lowering position and also in the inboard position, a socket in the bottom of the davit, a fixed base with vertically projecting pin, a projection on the base, a projection in the socket, and a spiral spring wound around said pin and whose ends bear against said projections.

5. A ships davit, comprising, in combination, a single davit turning upon a vertical axis and from which the boat is slung centrally by a single rope, winding gear on the davit for lowering and raising the boat, means for automatically locking the davit in the outmost lowering position and also in the inboard position, a socket in the bottom of the davit, a fixed base with a vertically projecting pin, a projection on the base, a projection in the socket, a spiral spring wound around said pin and whose ends bear against said projections, and a washer interposed between said spring and the upper end of the socket.

6. A ships davit comprising, in combination, a single davit turning upon a vertical axis and from which the boat is slung centrally by a single rope said davit being stepped at a lower deck of the ship and passing up through the boat deck of the ship, means located in the boat deck for locking the davit in the outmost lowering position and also in the inboard position and spring means at the bottom of the davit for checking the movement of the same.

7. A ships davit comprising, in combination, a single davit turning upon a vertical axis and from which the boat is slung centrally by a single rope connected thereto in the longitudinal center line thereof said and the socket so as to check the movement of the davit.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN GRAHAM.

davit being stepped at a lower deck of the ship and passing up through the boat deck of the ship means located in the boat deck for locking the davit in the outmostlowering position and also in the inboard position, a socket in the bottom of the davit, a fixed base with projecting pin entering said socket and a spring interposed between the base W'itnesses:

HUGH D. FITZIATRICK, WILLIAM G. CARRUTHERS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

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