Improvements in Davits, and the Means for Operating the same.
Year: 1895

page_text: Date of Application (in United Kingdom), 31st May, 1895
Complete Specification Left, 31st May, 1895-Accepted, 13th July, 1895
Improvements in Davits, and the Means for Operating the same.
I, JAMES WILSON MCKINNON, of 218 St. Annes Avenue, in the City of New
York, County and State of New York, U.S.A., Inventor, do hereby declare the
nature of my invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My invention relates to improvements in davits and the means for operating the
same.
Heretofore the life boats of ships have been swung from davits by tackle
operated by hand, and the davits have also been swung in- or out-board by hand.
It is the object of this invention to furnish such a construction and organization
of the davits and connected mechanism that the same can be much more
expeditiously operated by hand or by power.
I have also provided such an organization of parts, that when the power is
manual, a single man can quickly effect both the raising and lowering of the boats
and the swinging of the davits.
Referring to the drawings.
Fig. 1 is a side elevation, partly broken, of the apparatus. The clutch on the
right is shown engaged with, that on the left disengaged from, the corresponding
worm.
Fig. 2 is an end elevation of the same parts as are shown in Fig. 1.
Fig. 3 is a plan view on a smaller scale.
A Aare davits, a a being foot blocks, and a straps by which the davits are
movably supported so as to turn on a vertical axis.
B B are tackles rove through the eyes bb, over the sheaves c c, past the
sheave d, that is carried by a bracket fixed to the ship's side, and around the
drum D journaled in blocks e e fastened to the side of the ship; D₁ being a gear on
the said drum.
GG are travelers swivelled on the tackles B B, and consisting of yokes 9 and
sheaves 9' 9' which latter travel on the guides w w which are secured to the ends
of the boat W.
While I prefer to use the travelers and guides I can of course use the ordinary
block and tackle.
I intend to operate the davits either by hand or by a suitable power motor, and
I provide for operatively connecting the davits and drum with the motive power in
the following manner: H is a driving shaft turning in bearings h h on the side of
the ship, to which haud power is applied through the crank, or which may be
driven by any suitable motor. I is a worm working loosely on the shaft, but held
against lateral movement, i being a clutch face, on the end of the worm.
Di 1
J is a

page_text: clutch sliding on, and rotating with the shaft, H, J' a hand lever provided with a
pivoted yoke K that works between shoulders on the clutch J. L L' are gears
respectively on the davits A A¹, and meshing with the worms I I. Said clutch J
may also be arranged to be operated automatically.
M M are pinions sliding on and revolving with the shaft H, and arranged to
mesh with one of the gears D D¹. The collars m m of said drums are provided
with peripheral grooves n n, adapted to receive the head of a stop O, (which
is pivoted at p,) when it is desired to hold the pinions M M out of mesh with the
gears D' D¹. When it is desired to hold the said pinions in mesh with the said
gears, then said pinions are slid laterally until they engage with the gears D¹ D',
and then the stops O are dropped behind the collars m m.
To operate the davits, any suitable power being applied to drive the shaft H,
the clutch J. on one side, as the right, is thrown into engagement with its worm !,
and the gears Di I being out of mesh with the pinions M M. Now the davit A
rotates a quarter turn as indicated by the arrow 1, Fig. 3, bringing the boat to the
position of the lower dotted lines. Then the clutch of the left hand worm is thrown
into engagement, and the davit A' makes a quarter turn as indicated by arrow 2,
the davit A still continuing its movement. When davit A is at the quarter the
boat will be in the diagonal position, Fig. 3. Now the clutch is disengaged from
the right hand worm, arresting davit A, while the davit Al goes on turning; until
the boat is out board. At this point the left hand clutch is disengaged from the
worm, and davit A¹ arrested. Now the pinions M M are thrown into mesh with
the drums D D, the driving shaft H being momentarily stopped for the purpose,
and the boat is lowered' away.
While I prefer the arrangement of the worm I and gear L to rotate the davits,
I can employ any other suitable means for the purpose.
Regarding the special construction shown in Fig. 1, it will be observed that the
crank, is the equivalent of the power motor used when the davits are operated
by such motor. The arrangement of the worms, the gears on the davits, the
pinions on the shaft H, and the gears on the drums is such that one man can
operate the mechanism both for swinging the davits and lowering the boat.
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:
1. The combination of rotatable davits, a shaft provided with worm gears
meshing with gears on said davits, clutches on said shaft for engaging and
disengaging with a clutch on said worms so that said davits may be each
independently rotated, and means for rotating said shaft.
2. The combination in a device for operating davits, of a main shaft,' revolving
davits adapted to be operated from said main shaft, a winding drum for the tackle
also adapted to be actuated from said main shaft, and means on said main
shaft for independently rotating either of said davits and operating said winding
drum.
3. The combination of rotatable davits, a driving shaft, gearing on said shaft for
rotating either of said davits independently or both together, tackle carried by the
davits, a winding drum for said tackle, and gearing for driving said winding drum
from said shaft.
day ui imay
S. S. BROMHEAD,.
97 Newgate Street, London, E.C., Agent for Applicant.