Improvements in and connected with Davits for Ships.
Year: 1897

page_text: Date of Application, 3rd Mar., 1897-Accepted, 17th Apr., 1897
[Communicated from abroad by JAMES WILSON MCKINNON, of 111 Broadway,
"New York, U.S.A., Inventor.]
'
Improvements in and connected with Davits for Ships.
I, HUGH DONALD FITZPATRICK, of 70 Wellington Street, Glasgow, in the
County of Glasgow, Registered Patent Agent, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to improvements in davits for raising and lowering the
boats of ships.
Especially the invention relates to the gearing which actuates the davits in such
manner that the rotation of the davit-beads shall carry the boats out-board and
in-board clear of the davit standards, and that when each davit has swung to its
out-board position, it shall stop automatically. The invention also relates to
gearing so that a loaded boat will remain at any point of suspension. In this
manner the safety of the persons in the lowering boat is greatly promoted, the
danger of a capsize being reduced to a minimum.
Fig. 1 is a front elevation of the davits and their attachment;
Fig 2 is an end elevation of the same parts;
Fig. 3 is a plan view of the apparatus. The successive positions of the davits
and the boat are indicated by dotted lines;
'
Figs. 4, 5 and 6 are details of the device for operating the clutch which throws
the davits and the hoisting drums in and out of operation, Figs. 4 and 5 being
plans and Fig. 6 an elevation partly sectioned.
A is 'a' boat, resting on supports B; C and D being davits.
respectively the bulwark and deck of a ship.
E and F represent
G and H worm gears on davits CD; said gears working through openings in
the bulwark E as shown. In practice said gears G H may either be complete
wheels or semi-circular segments, and each carries lugs 9 for throwing out the
davit clutches.
"II are worms meshing with G H and turning freely on counter shafts K L,
which turn in suitable boxes carried by yokes k that are supported on the
bulwark E.
M is a pinion turning freely on shaft K and meshing with pinion N fixed on
shaft O which turns in boxes in suitable supports as shown. P is a worm fixed on
said shaft O, and meshing with worm gear Q on shaft R. Said shaft R has fixed
at each end hoisting drums S S₁ for the ropes T T', rr being supports for the
shaft R. The aforesaid shafts K L are operated by the cranks k fixed in
wheels K' L', and they can if desired be operated by a motor.
'I prefer a pinion N, worm P and gear only at one side, but, a similar pinion,
worm and gear, with counter shafts may be provided at the other end. The parts
are interchangeable, so that, in any case, I can shift the pinion N, worm P, counter
shaft O and worm gear Q from one end to the other end of the shaft R.
I is a clutch face on the aforesaid worms I I, and M' a similar clutch face, on
the pinion M. V is a corresponding double clutch turning with the shaft K, but
sliding thereon by means of proper feathers or ribs, between said clutches I¹ M³,
o as, in the one position (Fig. 4) to engage with the clutch I, and in the
Price Bd7
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page_text: other position with the clutch M. is a circumferential groove in clutch V,
and w is a pin working therein and depending from a clutch lever W, which
is pivoted on a stud w, in a standard w³. X is an auxiliary bent lever pivoted
on stud "z 'and having a socket provided with inclined sides . A square
head fixed on pin w normally rests in the socket. A spring y tends to hold
lever ✗ against pin w³.. Z is an arm pivoted on stud w' and pin connected
at z with the end of lever X. The inner end of said arm Z is in the path of the
lug g, and it is provided with a short outer, end z¹ which normally bears against a
pin won lever W. When the parts. are in the position of Fig. 4, the levers W
and X and arm Z, form, in effect, a single lever, and any motion, imparted to arm Z
will move lever W, and therefore the clutch V..
TT are hoisting ropes and wound respectively on the drums S S'. They are
guided by the sheaves.T' carried in hangers t¹ that are swiveled in the heads of the
davits CD, and by sheaves T³, and sheaves T
The shaft R could be operated by a separate wheel or crank on the shaft O.
OPERATION.
The boat A resting on its supports as indicated in Fig. 1, a sailor throws. right
hand clutch V off the clutch I and into the clutch M. Then he turns the right
hand crank K² in the proper direction, whereby the boat is raised off, the
supports B. The sailor then throws the right, hand clutch V. off clutch Mand
into clutch I', the pitch of the worm P preventing the drums S Sfrom turning
and letting the boat fall. Now the sailor goes on turning the right hand crank K³,
and the davit C begins: to rotate, reaching at first the quarter and then the out-
board position indicated by the dotted lines on the right of Fig. 3., As the gear G
revolves the lug 9 comes against the arm Z, throws off the clutch V (Fig. 5) so
that davit C ceases to move as soon as it reaches the out-board position. When
the sailor on the right first, begins to turn his davit as described, the sailor on
the left, having first thrown his clutch V into the corresponding clutch on its worm
for operating the left hand davit D, gives a few backward turns to his, crank 12, to
ease the strain on the rope. T¹. Then, as soon as the right davit reaches the
quarter, he begins to turn the left davit out-board and continues until the lug
throws off the clutch V in the manner described for the right hand davit. In
this manner the davits carry the boat out-board, clear of the standards of the
davits..
When the boat is out-board the right hand sailor throws clutch V into clutch M
and lowers away, the boat descending on an even keel, because both drums S S¹
are fixed on the same shaft R.
7.4
To raise and return the boat to its standards, the sailor on the right turns his
crank to wind up rope T'. When the boat is at proper height, he throws clutch V
into clutch 1 by first throwing lever X off the head w³, then shifting lever W,
which now moves freely notwithstanding lug g is against arm Z.. Now he begins
to turn the davit C in-board and very soon (as the lug g turns away) the spring y
brings the lever X against head w³, said head entering the socket as before. When
davit C.has reached the. quarter, the sailor on the left throws in his clutch and
begins to turn davit D. Thus the boat is brought in-board, and over. the
supports B. Now the sailor on the left stops turning, and the sailor on the right,
throwing clutch V off clutch, I¹ into clutch M¹ lowers away, the boat descending
evenly into the jaws of the supports B.
i
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
7.1
1. The combination with a davit, of a gear on the davit, a worm. meshing
therewith, a clutch for actuating the worm, and devices actuated by the davit for
throwing the clutch substantially as described

page_text: 2. The combination with a davit, of a gear thereon, a worm meshing with said
gear, a shaft driving the worm, a hoisting drum, a gear therefor, a worm, meshing
with the gear of the drum, and a train of gears connecting the shafts which
actuate said worms, substantially as described.
3. The combination with a davit and gear thereon, of a worm meshing with said
gear, a hoisting drum, a gear train for driving the same, a clutch on the worm an
on the initial gear of the train, and a double clutch adapted to engage alternatively
with the clutch on said worm and on said initial gear, substantially as described.
4. In a davit operating mechanism a clutch controlling the actuating mechanism
and operated by the revolution of the davit so as to arrest the davit at the out-
board position, substantially as described.
H. D. FITZPATRICK,
70 Wellington Street, Glasgow.