Improvements in Centre Boards for Sailing Boats.
Year: 1895

page_text: Date of Application, 5th Mar., 1895--Accepted, 27th Apr., 1895
COMPLETE SPECIFICATION.
Improvements in Centre Boards for Sailing Boats.
We ATKINS STOVER of 61 Norman Avenue, Brooklyn in the County of Kings
and State of New York, United States of America, Machinist, and GABRIEL
DUVAL CLARK of 154 Noble Street, Brooklyn, in the County of Kings and State
of New York, United States of America, Clerk, 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 :-
The invention rolates to improvements in centre boards for sailing craft, in which
provisiou is made for raising and lowering the board at pleasure, and for adjusting
it laterally, at an angle to the vertical plaue, through the longitudinal axis of
the keel.
A practical embodiment of the invention is represented in the accompanying
drawings, in which―
Fig. 1 is a top plan view of the centro board, centre board trunk, aud portions
of the bottom of the boat in immediate proximity thereto.
Fig. 2 is a transverse vertical sectiou through line za of Fig. 1.
Fig. 3 is a longitudinal vertical section through line y y of Fig. 1; and
Fig. 4 shows another form of device for swinging the centre board laterally.
The keel of the boat is denoted by A. It is provided, as is usual, in connection
with centre board craft, with nu elongated opening a therethrough, but in the present
instance instead of making the opening a of sufficient width to permit the centre
board to loosely rise and fall through it, it is made wider, for the purpose of
permitting the board to swing laterally, to adjust at different angles to the keel.
On the keel, the centre board trunk B is built, and the lower portion of the trunk
is made sufficiently wide to receive thereon a swinging piece C, provided with au
opening therethrough, adapted to loosely fit the centre board D. The piece C is
preferably formed of some heavy material, such, for example, as lead, or composition
metal, and is sufficiently deep to afford a firm bearing for the centre board, to hold it
in the desired lateral adjustment against any liability of its wrenching itself out of
position. The picce C, when made of such heavy material, performs at the same
time the double function of forming a strong and sufficient holder for the centre
board, and serves as effective ballast, because of its location low down and resting
on the keel. The piece C also keeps the slot a partially closed, to prevent the
water from rushing into the trunk, and impeding the speed of the boat. The piece C
gradnally tapers from its broader central portion towards its euds, so that it may
rock or swing laterally upon its central portion, as a pivot, within the broadened
lower portion of the centre board trunk, to carry with it the centre board D into
such lateral adjustment as is desired. For the purpose of rocking or swinging the
said piece laterally, to adjust the centre board either in line with the longitudinal
axis of the keel, or obliquely thereto, the following arrangement may be employed:-
The said piece C is provided with a nut. C, loosely engaged therewith, by inserting
the stem thereof in the end of the uprising arm &, fixed to the end of the piece C.
A screw E is mounted transversely in the centre board trunk, to engage with the
said nut, and provided with an operating crank e, so that when the Ecrew is turned in
one direction, it will cause the nut to travel thereon, to swing the piece C in one
direction, and when the screw is turned in the opposite direction, it will cause the
nut to travel thereon, and swing the piece C in the opposite direction.

page_text: The centre board D is here shown as slightly oval in horizontal section, for the
purpose of making it stiff, and it is elevated by means of a pair of flexible
connections dd, which extend up to, aud wind about the shaft F, which is jourualled
at the top of the centre board trunk, and is provided with an operating crank f
The weight of the centre board is sufficient to cause it to drop under the induence
of gravity, when the connections d d' are slackened.
The centre board itself consists of a hollow casing, provided with a filling of lead
or other suitable heavy material.
In operation, when the boat is running free, the centre board may be lowered
to the desired extent in a plane corresponding to the longitudinal axis of the keel.
But when the boat is sailing closed hauled, and working to the windward, the
centre board may be turned obliquely to the longitudinal axis of the keel, so as to
cause its forward edge to point more or less to the windward of the longitudinal
axis of the keel. As the boat comes about to stand on another tack, the centre
board may be swung Interally, causing its forward end to point on the opposite side
of the longitudinal axis of the keel, and to the windward thereof. The amount of
obliquity which it may be found feasible to give the centre board will be a matter
of judgment, but in any event the tendency will be to cause the boat to creep to
the windward, effectually overcoming such loss as it may tend to make to the
leeward.
Instead of using the screw and nut for swinging the centre board support laterally,
the structure shown in Fig. 4 may be employed, where a vertical shaft G is provided
with a toe or lateral projection g, arranged to enter a slot in the end of the centre
board support. The vertical shaft G may have a crank g' at its upper end, for
operating it.
It is obvious that other slight changes might be resorted to in the form and
arrangement of the several parts, without departing from the spirit and scope of
the invention.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that what
we claim is―
The combination with the elongated centre board trunk, of a centre board
supporting piece mounted within the trunk, and consisting of a central broadened
portion forming a pivot, and narrower portions extending in opposite directions
from the broadened portion, the centre board mounted in vertical adjustment in
the said supporting piece, means for swinging the said supporting piece laterally
on its central portion, as a pirot, and menus for vertically adjusting the centre
board, substantially as set forth.
Dated this 1st day of March 1895.