Improvements in and connected with Drop Keels.
Year: 1894

page_text: Date of Application, 7th Feb., 1804
Complete Specification Left. 7th Dec., 1894-Accepted, 7th Feb., 1895
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ותמרות
Complete Specification Left. 7th Dec., 1894-Accepted, 7th Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in and connected with Drop Keels.
I, HERBERT WYNNE FAIRBRASS, of No. 47, Haymarket, in the Administrative
County of London, Naval Architect, do hereby declare the nature of this invention
to be as follows:-
My invention relates to improvements in and connected with drop keels and is
particularly applicable to that type of keel known as bulb or ballast keels and to
weighted centre boards. It consists in improved mechanism for housing, lowering,
suspending and canting the keel or centre board and is carried into effect as
follows. The bulb keel or weighted centre board is made in two halves which are
pivotted longitudinally upon an axis below its centre of gravity. Along each of.
the opposite or upper and outer edges of the said halves, there is a longitudinal
plate pivotted, and these plates are connected by lazy tongs in equivalent devices
to the points or line of suspension. If there is not a bulb keel, the necessary
ballast may be made fast along the bottom edges of the plates. The lazy tong
gear works in or from a travelling head or its equivalent, and suitable tackle is
provided for letting down and hauling inboard the keel or centre board, either or
both, as well as for adjusting the position of either of thein in respect either of fore
or aft or as to whether the said keel or centre board is canted more or less or not
at all.
Dated this 2nd day of February 1894.
PHILLIPS & LEIGH,
Agents for the Applicant.
H али сонцесто
I, HERBERT WYNNE FAIRBRASS of No. 47 Haymarket, in the Administrative
County of London, Naval Architect, 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 improvements in and connected with drop keels and is
particularly applicable to that type of keel which is known under the various
appellatives "bulb keel," "ballast keel,"
,"fin keel," "centre board," "lee board,"
and the like.
It consists in the combination of an improved lee board, centre board or drop
keel, with mechanism for housing, lowering and suspending the same, and also in
the combination of weighted appendage or bulb keel, with an improved centre
board or drop keel and mechanism for housing, lowering and suspending the same.
In addition to the ordinary and well known uses to which the various keels and
boards referred to, are put, I wish to point out the applicability of the present
invention to vessels of the limited stability of torpedo boats, the object of such
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page_text: .
application being to prevent the well known and frequently fatal rolling to which
such vessels are subjected by a heavy cross sea, for which prevention my invention
is, from its nature, well adapted.
Referring to the accompanying drawings which are to be taken as part of this
Specification and read therewith:-
Figure 1 is a side elevation of a two part hinged bulb keel constructed
according to my invention. The bulb keel is shewn by the full lines as lowered
to its lowest level, and by the dotted lines, as suspended at a level nearer to the
bottom of the boat.
Figure 2 is a side elevation of the same keel shewing it housed or inboard.
Figure 3 is a part sectional end elevation corresponding with the full lines of
Figure 1.
Figure 4 is a plan of Figure 2.
Figure 5 is a side elevation of a boat fitted with a single solid bulb keel.
Figure 6 is a sectional side elevation of the invention illustrated in Figure 5, but
on a larger scale, and shewing the connection between the keel and the housing and
lowering gear.
Figure 7 is a sectional side elevation on the same scale as Figure 6, shewing the
bulb keel as housed or inboard.
Figure 8 is a part sectional end elevation corresponding with Figure 6.
Figure 9 is a detail illustrating a modified construction of centre plates.
Referring to Figures 1 to 4, a is the underside of a boat's keel and b the trunk
or internal casing.
c, c are the two parts of the weighted appendage or bulb keel and they, together
with the rule joint d on which they are hinged to each other, constitute my improved
two part hingeing bulb keel. The pivot of the rule joint dis fixed below the centre
of gravity on the keel and, preferably, at the bottom and adjacent corners of the
two parts c, C.
The two adjacent edges c', c¹, of these latter, are both rectilinear
and radial to the axis of the joint d so that when they are in touch with each other;
the two parts c, c form, practically, one continuous keel, as shewn by the respective
full lines in Figure 1.
e is a bolt passing thwartships from one side of the trunk to the other. It is
either fixed to the trunk so as to be capable of motion independently thereof, as
indicated by the respective full lines, or provision is made for it to be movable fore
or aft by mounting it in slots e' formed in the sides of the trunk, as indicated by
the dotted lines in Figure 1. This bolt constitutes the point of suspension for the
keel, the centre board, and the housing and lowering gear of either.
This housing and lowering gear consists of a lazy tongs. The levers f, f¹
thereof are of equal length and both have their fulcra in the axis of the bolt e when
only one such bolt is used, but I may if preferred, make use of two bolts e², eat
the same level, in which case, the lever has its fulcrum on the former and the
lever fits fulcrum on the latter, as indicated by the dotted lines in Figure 6.
g, g' are a second pair of levers hereinafter referred to as the centre plates. Like
the levers f, f, they are of equal length, and have their fulcra on a pivot g
common to them both and situated, preferably, midway of them. Their upper
ends are pivotted to the respective lower ends of the levers f, f¹ by pivots g³, g*,
while their lower ends are pivotted to the upper and adjacent corners of the
parts c, c, by pivots c², c².
Each lever ff is duplex, i.e., it consists of a pair of parallel bars. The centre
plates g, g' are adapted to move over each other, side to side, after the manner of
scissors or lazy tongs; or up to and away from each other after the manner of bars
jointed to each other by a central rule joint. This last described modification is
illustrated in Figure 9. The upper ends of these centre plates stand between, and
their upper portions are consequently adapted to move between, the two bars of the
respective lever, f. In cross section each centre plate is shaped so as to present
a sharp edge to the water. Each portion or half bulb c, c, is slotted in the planes

page_text: of the respective centre plate in order that the keel, as it is housed, may pass over
the ends thereof.
A gear for letting out and hauling the lazy tongs inboard is provided. My
invention does not limit me as to the type or constructional details of the gear
which I make use of. The one illustrated answers every purpose. It consists of
a handwheel fast on a shaft ' journalled in bearings . i is a worm fast on the
shaft and engaging with a worm wheel i¹ fast on the axis of, and between, two
drums journalled in brackets 3 projecting from one end of the trunk b, each of
the said drums having made fast to its periphery, one end of each of the two
suspension chains j, j. The latter are led respectively over antifriction
pulleys, supported on fixed axes in the trunk and then made fast by their
free ends to the lower ends of the levers f, f¹, respectively. The hand wheel h
may be fitted with a telescopic or radially adjustable handle h³, as indicated by the
dotted lines in Figures 6 and 7.
The bulb keel is lowered by paying out the suspension chains j¹, j, the weight of
the former carrying it down into the water. It is raised or housed by hauling the
chains in, less or more, as may be required.
Instead of making the weighted appendage or bulb keel in two parts pivotted
together in the way illustrated in Figures 1 to 4 and described therewith, I may
make it in one piece as heretofore in that respect, but I provide for the reciprocal
motion of the lower ends of the centre plates g, g¹ in conjunction with the
permanent connection thereof to the said keel by means of a slot and stud
device, the bulb itself being hollowed longitudinally and mid way of its two sides
so as to form a suitable recess adapted to pass over the lower ends of the centre
plates g, g during the act of housing as well as to receive the slot and stud
devices.
Such a modification in the construction of the bulb keel and of the adjacent
C is a solid bulb
ends of the centre plates is illustrated in Figures 5 to 8.
keel in one piece. is the recess adapted to receive the lower ends of the
centre plates g, g' and the slot and stud devices. Each of these latter consists of
two slots, cut in the sides of the recess k. Each slot stands exactly opposite its
neighbour, of which it is a counterpart in every respect. A pair of slots receive
the two studs projecting from the sides of the respective.centre plate. Con-
sequently, the separation of the lower ends of the centre plates g, g' lifts the bulb C
whilst the approximation of them, will drop it.
It is to be noted that the combination of the two centre plates g, g¹ constitutes a
drop keel or centre board and the combination of them with pivotted levers ƒ, ƒ'
falls within the scope of the present invention.
It should be distinctly understood that the present invention includes the
application of any of the constructions described above to what is well known as
a lee board, and the claims to this Specification are to be read in that sense.
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 bulb keel or weighted appendage, lazy tongs and gear
for letting out and hauling the said tongs and keel inboard, as set forth.
2. The combination of the herein before described two part hinged bulb keel,
lazy tongs and gear for letting out and hauling the said tongs and keel inboard,
as set forth.
3. The combination of the herein before described single or one piece bulb
keel, lazy tongs and gear for letting out and hauling the said tongs and keel
inboard, as set forth.
4. The combination of two pivotted centre plates pivotted together and together
constituting a centre board or drop keel, pivotted levers, and gear for letting out
and hauling the said centre board and pivotted levers inboard, as set forth.

page_text: 5. The hereinbefore described combination of keel for board of any type and
mechanism substantially as specified and thereby adapted to house, lower and
suspend the same, as set forth.
Dated this 7th day of December 1894.
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.