Improvements in and relating to Ships' Davits.
Year: 1895

page_text: Date of Application, 1st June, 1895
Complete Specification Left, 1st Apr., 1896-Accepted, 30th May, 1896
[Communicated from abroad by HUGH MCGILVRAY, Master Mariner, William
Street, Dunedin, New Zealand, and ALFRED DRAY, Mechanical Engineer,
Osborne Street, South Dunedin, New Zealand.]
Improvements in and relating to Ships' Davits.
I, JOHN BOLTON SOMERS, of 10, Plimsoll Street, Poplar in the County of
Middlesex Pensioned Serjeant of Police do hereby declare the nature of this
invention to be as follows:-
:
My invention relates to improvements in and in connection with ships davits, and
consists of 1st, a method of mounting the davits as at present made and used, in
combination with a means by which both davits may be swung out simultaneously:
by one person, 2nd, of an improved method of mounting the davits as at
present made, by which these do not require to be swung out as hitherto, but are
declined or tilted outwardly from a true vertical position (when at rest) to that of
an angle suitable to enable the boat to be lowered therefrom clear of the vessel,
which operation, by the aid of suitable gearing, inay also be effected by one person.
3rd. Of a method of constructing the skid or chocks upon which the boat rests
when not in use, by which the outer pair of chocks are caused to recede within the
skid when the boat is to be lowered, which permits, that the boat may be lowered
direct from the skid without being first raised from the chocks as hitherto, the
objects of my said invention being to provide a means, by which the boats may be
lowered more quickly, with less hazard of being stove in, and by the employment of
less hands than hitherto.
For the purposes of my invention and according to one method of construction,
I employ dayits of ordinary form, the heels of which are circular in cross section,
and are socketed in suitable standards, in which they may revolve, the said
standards having flanges at their upper ends, and each provided with a pair of
brackets, which serve as bearings for a horizontal shaft, the said shaft having
thereon a left-hand threaded and a right hand threaded worms, which gear with
like worm wheels, keyed or otherwise fixed upon the davits, and by the means
of a suitable handle or handles, the said shaft may be rotated, which rotates- the
davits in opposite directions, but both outwardly, so that the boat suspended from..
their heads is thereby placed outwards clear of the side of the vessel, and may
then be lowered in the usual way. A vertical hole or slot is formed in each of
the said worm wheels and two corresponding holes or slots in the flange cf each
standard, and by the insertion of a pin or bolt into the hole in the worm wheel and
one of the holes in the flange, serves to keep the davits firm when not in use, and
by insertion into the other hole in the said flange, perfectly firm when in use.
Each davit may be provided with separate gear so that each may be operated
separately instead of collectively by the aid of the horizontal shaft as described.
By a second method of construction the said standards are bifurcated at their
upper ends, and between such bifurcations, a davit of ordinary form is pivotally
suspended upon each standard, in such a manner that their upper ends may be
tilted outwardly over the side of the vessel when their lower ends are brought
inward. The lower end or keel of each davit. is rectangular or polygonal in cross

page_text: section, and each of these are fixed in a socket formed in a metallic quadrant, the
curved base of each of which is provided with teeth which gear with a worm, the
spindles of which are journalled in suitable bearings, in and extend at one end
through their respective standards, and upon each of such extensions is mounted a
worm wheel in gear with corresponding worms upon a horizontal shaft borne by
the said standards. The said davits in their normal position would be perfectly
vertical, with their heads pointing outwardly towards or partly over the side of
the vessel, and with their respective quadrants concealed within the bifurcations of
their respective standards, in which position each may be firmly retained by a pin
or bolt engaging with a hole therein and a corresponding hole in the standard, and
when the boat is to be lowered such pin would be first removed, and rotation
be imparted to the said horizontal shaft, by the means of a handle or handles,
and this by rotating both worms would operate both quadrants and their davits,
tilting the latter outwardly until the boat was clear of the vessel, when this
may be lowered in the usual way, the weight of the boat itself assisting the operation.
As in the previous method I may dispense with the horizontal shaft and arrange
that each davit may be operated independently.
In either of the above arrangements the skids upon which the boat rests, when
not in use, as so constructed that while the inboard chocks are fixtures, the outboard
chocks are swivelled at their inner ends, and when in use for supporting the boat
upon the skid, are retained in position by suitable bolts or pins engaging therewith
and the ends of the skid, and by the withdrawal of such pins, the said chocks
would sink by gravity into recesses in the skid, so that the skid would be clear
towards outboard for the removal of the boat without this being lifted, suitable
means being provided for removing both the said bolts simultaneously and
quickly.
Dated this lot day of June 1905
GEO. THOS. HYDE,
1 Broad Street Buildings, Liverpool Street, London, E.C.,
Agent for the Applicant.
I, JOHN BOLTON SOMERS of No. 10 Plimsoll Street, Poplar, London, Gentleman,
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:-
"
My invention relates to apparatus for launching ships' boats and securing them
in position when not in use, and has for its objects to provide apparatus by which
ships' boats may be set free and launched rapidly in a simple, certain and effectivė
manner with little expenditure of labour.
Further objects are to make my apparatus specially applicable for lowering
boats easily and rapidly either over the higher or lower side of a vessel when the
latter has a list, as when wrecked upon rocks.
Hitherto there has been considerable difficulty, and in some cases an insuperable
difficulty in lowering boats from a vessel which has been wrecked and has settled
down with a considerable list upon rocks.
"I carry out the objects of my invention by employing davits which, as regards
their upper parts, are similar to those at present in use, but the lower parts are
provided with a collar, trunnions, and suitable bearings. Upon the lower extremity
of the davits I furnish quadrants' and racks, and engaging with the racks' I gear
worms. Motion is imparted to the said worms by worm wheels,"both worms and

page_text: wheels being secured upon the same shaft. The worm wheels are actuated by
other worms, shafts, and handles. The various trunnions and shafts are carried in
suitable bearings upon pillars.
When the boats are not in use they are stowed upon chocks and are held down
in their places by gripes. The davits are secured by guys which attached to the
head of the davits pass downwards and through eyelets on the deck and thence
to bolts in the skids. These bolts also hold the lower ends of the beforementioned
gripes, and one pair of bolts maintains one of each pair of chocks in position.
Links connect these several bolts to arms on a rocking shaft which having a hand
lever and quadrant at one end, is supported upon the deck by bearings.
My apparatus operates by moving the hand lever, when the bolts will be with-
drawn. The gripes, guys, and chocks are thus liberated by one operation. The
boat may now be lowered by swivelling the davits in the usual manner, the distance
apart of the davits being slightly greater than the length of the boat; but if the
vessel has such a list as to make it impossible to lower the boat clear of the sides
I bring my quadrants and racks and their gear into operation. By moving the
davits on their trunnions the upper parts are made to overhang the ship's side
taking the boat with them to any required extent within the range of the quadrants
and racks. When clear of the ship's side the boat may be lowered by the usual
blocks and tackle.
In cases where my worm gear may be desired to be applied in a modified
form to existing vessels without going to the expense of fresh pillars and davits,
I secure worm wheels upon the davits, and brackets to the existing pillars for
carrying a shaft and worm to gear with the said worm wheel.
Each set of gearing may be worked independently, or the shaft may be
extended from one davit to the other, so that both may be worked simultaneously.
In the latter case the shaft runs close to the handrail and causes little or no
obstruction.
In order that my invention may be more easily understood by one skilled in
the art to which it appertains, I will now proceed to describe the same in detail
and for that purpose shall refer to the accompanying sheets of drawings, whereon
similar letters and figures of reference indicate corresponding parts throughout the
several views.
Figure 1 is a side elevation of my apparatus shewing the boat stowed and secured
in position, and with part of the handrail removed.
Figure 2 is a plan of the same.
Figure 3 is an end elevation of the same.
Figure 4 is a front elevation of a pillar, and lower part of a davit, on a larger
scale.
Figure 5 is a side view of the same, partly in section.
Figure 6 is a front elevation of a pillar and lower part of a davit, provided with
my worm and worm wheel.
Figure 7 is a plan of the same.
The upper parts of the davits (a) are shaped similarly to those at present in use,
and are provided with the usual blocks and tackle (a¹). Upon the lower parts of
the davits (a), however, I provide collars (a 2) having trunnions (a 3) movable
within bearings (1) upon pillars (b). The davits are free to revolve within
collars (a 2) and are kept down in their places by collars (a 4) which are firmly
secured to the davits by screws (a 5) Figure 4. The ends (a 6) of the davits are
reduced to fit revolubly within boss (a 7) of quadrant (c). The circumferences of
quadrant (c) and its rack (c) are struck from centre of trunnion (a3), and the
quadrants fit between the two sides of pillars (6) which act as guides and prevent
said quadrants from revolving with the davits, and stops (c2) abut against said
pillars to prevent the quadrants from being revolved too far in either direction.
The worm (d) mounted on shaft () gears with rack (c¹) and is operated by worm
wheel (d2) also mounted on shaft (d), and worm (e) which gears with worm
wheel (d2), shaft (e), and handle (e 2). Shafts (d) and (e) are carried

page_text: respectively in bearings (d3) and (e3) upon pillar (6). Shaft (e¹) extends from
one davit to the other so that both the worms (e) are revolved simultaneously.
The skids (f) support the boats (f¹) and have chocks (2) and (3) to fit the
shape of the boats. Chocks (2) are fixed, but chocks (3) are made to fall
down by revolving upon their pins (f 4). Gripes (f6) hold the boats down in
their places upon the skids. The heads of davits (a) are connected together by a
spau (g) and the davits are secured by guys (g) which passing through eye-
bolts (92) have their ends looped through links (93) which engage with bolts (h).
Said guys (9) are hauled tight and held by lanyards (94). Links (3) couple
bolts (h) and (2) to tumblers (4) of rocking shaft (5), which is actuated by
hand lever (h 6). The links (77) upon gripes (6) are also held by bolts (h).
Bolts (2) hold, chocks (3) up to their work. Quadrant (7) is slotted to admit
said hand lever (6) and allows the same to be lowered.
t
The manner in which my apparatus is operated is as follows,-
The hand lever (16) is lowered in the direction shewn by the arrow, Figure 1,
to revolve rocking shaft (h5) when the bolts (h) & (2) will be withdrawn
simultaneously and thus links (7) and (93) are liberated, and chocks (3) fall
down. The davits are now free to revolve and the boat free to be put over the
side of the vessel. Handle (e 2) is now revolved to operate quadrants (c) and their
gear to turn the davits on their trunnions (a 3) and carry the boat outwards.
After traversing a certain distance the weight of the boat causes the davits to
revolve and accelerate the operation of lowering; and according to the list of the
vessel the boat may be carried out as shewn by dotted lines in Figure 3, in which
position it will be seen that the boat overhangs the side of the vessel to a
considerable extent and may be lowered safely even when the vessel has a
considerable list.
It will be obvious that my davits may be used as ordinary davits when the
vessel is on an even keel, when it would not be necessary to use my quadrants and
their gear.
Figures 6 and 7 shew my worm (d) and worm wheel (1) attached by bracket (j 2)
to an ordinary davit (a) and pillar (6). The boats are secured upon, and released
from the skids in the manner previously described, and the davits are then revolved
by turning handle (e 2) and worm (d). Worm wheels (j) are secured upon the
davits and as they are revolved by the worm, revolve the davits until the boat is
carried over the side of the vessel. The worms (d) Fig. 7 may be worked inde-
pendently or shaft (j¹) may be extended to the next davit and by supplying a left
hand worm to correspond with the right hand one on the first pillar, both davits
may be operated simultaneously.
I prefer to make such parts as the worms, worm wheels and bearings of gun
metal or tough brass, so that they will not become inoperative through rust.
From this description it will be seen that I. provide a simple, certain and effective
apparatus for securing ships' boats in position when not in use, and for rapidly and
easily lowering the same over a vessel's side either when on an even keel or with a
considerable list.
I wish it to be understood that I do not confine myself to the exact details
herein before mentioned nor to the exact configuration of the various parts, as
these may be varied in several ways by one skilled in the art to which my invention
appertains without departing from the spirit and nature of the same.
I am aware that davits in several forms have been used for lowering boats before
my invention, and I do not claim these broadly.
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. in
apparatus such as described herein for putting out ships' boats, davits
capable of revolving upon trunnions and of being operated by quadrants racks
and gear, substantially as and for the purposes set forth herein.

page_text: 2. In apparatus such as described herein and illustrated in Figures 6 and 7 for
putting out ships' boats, the combination with ordinary davits of worms, worm
wheel and gear, substantially as and for the purposes specified and as illustrated on
the accompanying drawings.
3. In apparatus such as described herein for securing ships' boats in position
upon the skids when not in use, the combination with rocking shaft (h5) and
bolts (h), of span (g), guys (9'), gripes (6), and links (7), substantially as and.
for the purposes hereinbefore set forth.
4. In apparatus such as described herein for putting out ships' boats, a rocking
shaft (5) and its connections for operating bolts (h) by means of hand lever (6),
substantially as and for the purposes described and illustrated.
5. In apparatus such as described herein for putting out ships' boats, the com-
bination with davits capable of revolving upon trunnions and being operated by
quadrants racks and gear, of a rocking shaft and its connections releasing bolts,.
skids, span ard guys, substantially as and for the purposes set forth herein and
illustrated.
6. Apparatus such as described herein for putting out ships' boats constructed,.
arranged and operating, substantially as set forth and illustrated.
Dated this 1st day of April 1896.
PHILLIPS & LEIGH,
No. 22 Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.