Improvements in and connected with the Housing and Lowering Gear of Drop Keels, Centre Boards, and the like.
Year: 1895

page_text: Date of Application, 24th Jan., 1895
Complete Specification Left, 24th Oct., 1895-Accepted, 30th Nov., 1895
NUTRIONAL SPECIFICATION.
Improvements in and connected with the Housing and Lowering
Gear of Drop Keels, Centre Boards, and the like.
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 the housing and
lowering gear of drop keels, centre boards, and the like; and the object of it is to
produce a wider centre board than those heretofore in use.
In carrying it into effect, I provide three plates. These are nearly rectangular
and of about the same size, viz., that of the desired centre board. The middle one.
has the drop keel (if there be one or the equivalent of one) made fast to and along
its lower edge. The two outer plates are connected to each other by being
pivotted centrally as to their areas upon the outer ends of a stud which passes
through a vertical slot in the centre plate, in which slot it is free to move in either
direction.
I pivot a pair of links upon a common, or a pair of separate pivots supported
near the top of the trunk more or less vertically over the stud in the middle plate,
and pivot the bottom ends of the said links to the respective top corners of the
outer plates.
The mechanism for working the above gear consists of a pair of chains and a
winding drum. The latter is journalled upon the trunk into which the centre
board is housed. Each chain has one end tast to the drum, and the other end,
after passing over a suitably placed guide or antifriction pulley, to the respective
outer plate. The antifriction pulleys are placed, respectively, fore and aft of the
centre board, and the last mentioned chain ends are connected to, preferably,
the respectively adjacent top corners of the outer plates. Consequently, when the
chains are wound in, the said plates are turned but in opposite directions, upon
their common pivot, the stud above mentioned.
There is a stud projecting from each outer plate, near its edge and about
midway of its height, and engaging in a horizontal slot in the centre plate. Each
stud and slot device is symmetrical in position and dimension with its fellow on the
other side of the central stud upon which the two side plates are pivotted. There-
fore are the two side plates, in respect of the material of them extending from
their top corners to the stud and slot devices in a line through the central stud
aforesaid, bell crank levers having their fulcra in such central stud, and constituting,
with the pair of links above described, a lazy tongs. The studs of the stud and
slot devices are the operative ends of the respective levers, and are adapted to
ift the centre plate by engaging with the top edges of the respective horizontal
lots therein.
The studs of the said devices may be continued through the respective horizontal
lots into arcual slots in the opposite side plates, such last mentioned slots being
hereby adapted to act as guides for the studs.
The drop keel may be circular in cross section, with a convex leading end, a
hickened middle section, and a diminishing tail.
.Dated this 24th day of January 1895.
PHILLIPS & LEIGH,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with the Housing and Lowering
Gear of Drop Keels, Centre Boards, and the like.
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 the housing and
lowering gear of drop keels, centre boards and the like.
In the Specification of a previous Patent granted to me for a similar invention,
No. 26611894, there are described sundry improvements in centre and other boards
and in the gear for housing and lowering both them and drop keels. Some of the
mechanisms described therein are repeated in the present Specification. The
present invention relates more particularly to centre lee boards and is restricted to.
them and their gear, the object of it being to provide a board of a greater width
than those hitherto in use.
Referring to the accompanying drawings which are to be taken as a part of this
Specification and read therewith:-
Figure 1 is a side elevation of a centre board constructed according to the
present invention and having attached to it a torpedo-shaped drop keel. Both
centre board and drop keel are shewn as lowered into the water.
"
Figure 2 is a side elevation shewing the same board and keel housed or inboard.
Figure 3 is a side elevation and Figure 4, an end elevation, of the middle plate
of the improved centre board together with an attached drop keel.
Figure 5 is an end elevation of one of the outer plates of the said board.
Figure 6 is a side elevation of the outer face of one of the outer plates.
Figure 7 is a side elevation of a boat fitted with the present invention and a drop
keel. The latter is shewn in the same position as in Figure 1.
'
u, a are portions of the usual keel timbers. They are slotted or otherwise'
modified, as heretofore, to admit of the passage of the centre board through them.
b, is the trunk in which the centre board is housed and from which it is lowered.
It stands upon, and is securely fastened to, the keel timbers a, a.
e is a bolt passed through the trunk from one side of it to the other, near the top.
and half way of the length of it. This bolt constitutes the point of suspension for
the centre board and the lowering and housing gear, as well as for the drop keel m
(when there is one). This gear consists of a pair of levers, f,f. The latter are
of equal lengths and both have their fulcra in the bolt e, which passes through
their top ends. Each lever consists, preferably, of a pair of parallel bars.
:
The mechanism for working the housing and lowering gear consists of a wheel h
fast on a shaft ¹ journalled in bearings 2. i is a worm fast on the shaft. It
engages with a worm wheel i fast on the axis of and between, two drums i³, 12,
and which axis is journalled in brackets projecting from one end of the trunk b.
Each of the said drums has made fast to its periphery, one end of the respective
suspension chain. These suspension chains are led over antifriction pulleys j, j³,
respectively, which are supported in fixed axes j, j, in the trunk b. The opposite.
ends of the chains are made fast to the lower ends of the levers f, f', respectively.
The mechanism just described is reproduced from the Specification of the
Patent above referred to and, of course, forms no part of the present invention.
The improved centre board consists of three plates x, y, z. These are of equal
width and depth and approximately rectangular in shape.
If there is a drop keel combined with the centre board, it is made fast to the
middle plate y along the bottom edge thereof, as illustrated in Figures 1 to 4 and 7,
the shape of the bottom portion of the said plate being modified as may be
+

page_text: necessary to make a workmanlike junction with the top of the keel. It must be
understood that the presence of the drop keel is not a feature of the present
invention. Whether it is itself pulled into the trunk when the centre board is,
housed, or whether it remains just outside depends upon its own diameter and
length.
w.is a vertical slot cut down the middle of the plate y from the top edge, to
enable it to clear the bolt e, as it is being hauled up to the top of the trunk.
v is a vertical slot in the centre of the plate y for the stud-upon which both the
outer plates and turn, to pass through and move up and down in.
0
u, u are two horizontal slots. They are of the same size and stand symmetrically.
in the plate y with reference to the vertical slot v, each one being aligned with the
middle of the latter and half way between it and the respective side of the plate,
as illustrated in Figure 3.
x, z are the two outer plates of the improved centre board. They hang one on
each side of the plate y and parallel therewith. They discharge, in part in the
present invention, the functions of the levers or plates g, g¹ of the Specification
No. 2661, of 1894. For that reason, the bottom end of the lever f.is pivotally
connected to the top outer corner of the plate by the bolt g³, while the top outer
coruer of the plate z and the bottom end of the lever fare similarly connected by
the bolt g*.
The plates and are held to the plate y and to each other by the following
devices. t is the stud above mentioned as passing through the vertical slot v and
serving as the axis of the outer plates and z. The last mentioned purpose is
achieved by the projection of the ends of the said stud t through a central hole in
the respective plate. The one (1) in the plate x, is shewn in Figure 6.
arcual slots. There is one in each outer plate x and 2.
8, s¹ are
These slots are of
the same size in every respect and are both struck from the axis of the
stud t as a centre, one arc on each side of the latter when the three plates x, y, z
re in their respective working positions. The radius of the inner edge of each
are is then equal to the distance of the said axis from the nearest end of
either of the horizontal slots u or u¹. r, rare a pair of studs one of which is
made fast to each side plate x, at the same distance from the axis of the
stud t as the radius of an arcual slot s or s¹ but on the opposite side thereof, in
order that it may pass through the respective slot u or u¹ in the middle plate y as
well as engage in the slot s or s', as the case may be, in the plate a or on the
opposite side of the middle plate. q, q¹ are stop plates-one on each outer plate.
A stop plate is fixed to the top outer corner of a plate in a plane, parallel with the
latter and of a sufficient distance from it to receive the respective corner of the
middle plate between them. The operative part of each stop plate is its diagonal
edge p. The abutment on the opposite outer plate with which a stop plate engages
is the diagonal edge o in the adjacent corner of the centre board, both abutment
and stop being cut to the same angle and positioned on their respective outer plates
so as to engage when the said centre board is down, as illustrated in Figure 1.
is a distance piece between each outer plate and its stop plate. Its inner edge is
concaved to clear the top outer corner of the middle plate y.
A centre board made according to the present invention is housed by winding in
he chains j,j. As the bottom ends of the levers f, f¹ are pulled up and apart the
uter plates and are turned on their common pivot t, the studs r, lifting the
middle plate y, moving during such lift, first outwards along the respective
orizontal slotu or u', as the case may be, and up the lower portion of the arcual
lot s or s as the case may be, and afterwards back along the said horizontal slots
nd through the remaining portions of the arcual slots.
The weight of the centre board suffices to lower itself when the chains are
aid out.
A suitable stop is provided in connection with the mechanism for working the
ousing and lowering gear, adapted to lock the centre board in any particular
osition.
.

page_text: 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. A centre or lee board consisting of the combination of middle plate, two
outer plates and devices by which the latter are held to the former and to each
other, as set forth.
2. The combination of middle plate, two outer plates, and devices by which the
latter are held to the former and to each other with a housing and lowering gear
and mechanism for working it, as set forth.
Dated this 24th day of October 1895.
PHILLIPS & LEIGH,
22 Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.