Year: 1886

page_text: Date of Application, 26th July, 1886.
Complete Left, 9th Apr., 1887.
Complete Accepted, 10th May, 1887.
I, DAVID MOFALL, of No. 213 East 35th Street, in the City and State of New
York, United States of America, Boat Builder do hereby declare the nature of this
Invention to be as follows:-
This invention relates to improvements in center-boards for sailing vessels and
means for attaching and operating the same.
It has for its object to provide a simple, inexpensive and effective center-board rig
which will strengthen instead of weakening the hull; allows the center board to be
quickly set and removed as sailing conditions and emergencies may require; and
obviates the necessity of the cumbersome trunk in the hold of the vessel required to
enclose the pivotted center-board in common use.
The invention consists in certain novel features of construction and combinations
of parts of the center-board rig which may be briefly described as follows: To the
under side or lower part of the keel of the vessel at the middle thereof, a plate or
shoe, preferably of metal, and which has a longitudinally-ranging slot formed therein
in its lower face, is securely attached. In this longitudinal slot the upper edge of the
center-board is made to fit snugly.
Tubular metal plugs, each having a fixed collar at its lower end are passed upward
through the slotted plate end the keel, and are made fast by means of a wide collar
screwing upon the upper end of each plug and bearing upon a cross plate or beam in
the hull so as to draw the lower collar up tightly with a water-tight joint against the
keel plate. Within these tubular plugs rods are fitted. The lower ends of these rods
are threaded to enter suitable thimbles or sockets fixed in the upper edge of the centre
board and which are provided with collars to make a close joint with the lower ends
of the tubular plugs when drawn up against them.
If these rods are made longer than the tubular plugs, provision is made for their
protection and lateral support above the tops of said plugs by means of tubes adapted
to screw at their lower ends into the screw-collars fitted upon the upper ends of the
plugs and which will serve as an extension thereof,

page_text: Chains or ropes are fitted to the upper ends of the rods and are carried over suitable
friction pulleys, preferably to the stern of the vessel, to be there made fast within easy
reach of the helmsman.
These chains, by holding up within the tubular plugs through which they pass, the
rods to which the center board is attached, serve to hold the center-board securely in
its proper vertical position under the keel.
Should the helmsman wish the vessel to drift away or make leeway with the tide or
current, he will unfasten the chains or ropes and the center board may then drop
down and away from the keel and float alongside, wholly inoperative. To set the
board for service, the helmsman will draw the chains or ropes taut again and thereby
cause the rods attached to the center-board to enter the tubular plugs and draw the
center-board snugly up to the keel again.
Should the center board run hard aground and hold the boat fast, the rods may be
unscrewed from the center-board and the boat be left free therefrom, and if the center-
board is not recovered a new center-board carried in the boat may be easily set by
running lines with floats attached down through the tubular plugs into the water and
letting them float astern where they may be caught, and the chains or ropes attached
to the rods in the center-board be then pulled back by means of said lines through
the tubular plugs so as to permit of the replacement of the center-board in manner
as above described.
To prevent the loss of the center-board when thus set free, and to permit it to be
hauled up out of the way when not needed, a chain or rope may be attached to the
upper, rear part of the center-board and carried back under the vessel to the arm of a
crane fitted to the stern of the vessel out of the way of the rudder, the free end of the
rope being carried and secured within reach of the helmsman. If preferred a second
chain or rope may be attached to the forward end of the center-board and carried
thence forward through a block on the vessel's bow and thence rear-ward to within
reach of the helmsman.
The tubes enclosing and supporting the rods which carry the center-board may be
firmly braced by stay-rods extending from collars fixed to the top of the tubes to the
sides of the hull and these rods may be fitted with turn-buckles for straining them up
tightly.
As a modification, tapering or conical stems or pins may be secured to the upper
edge of the center-board to fit into tapering recesses or sockets formed in the lower
end of the tubular plugs, to serve as a substitute for the rods herein before described,
the supporting chains or ropes being in this case connected directly to the ends of said
tapering pins.
In yet another modification of the invention auxilliary tubes are inserted within the
tubular plugs. The lower ends of these inner tubes are internally screw-threaded to
engage externally-threaded stems or pins fixed to the upper edge of the center-board.
The tops of these inner tubes have collars, provided with apertures to receive a bar or
lever, by which the tubes may be turned for screwing the pins or stems on the center-
board up into the lower ends of said inner tubes and thereby drawing the tops of the
center-board up snugly to the keel after the board has been drawn up into place by
the chains or ropes, which, passing through these inner tubes are attached to the
upper ends of the pins or stems upon which the tubes screw as described.
By providing the upper ends of these inner tubes with shoulders to bear upon a
cross-piece in the deck of the vessel, the center-board and keel and this cross-piece are
clamped tightly together by the screwing up of the tubes, thus bracing and
strengthening the frame of the boat. Should the center-board run hard aground it is
set free by unscrewing these inner tubes and slackening the ropes or chains led
through them from the center-board.

page_text: COMPLETE SPECIFICATION.
Improvements in Center-boards for Sailing Vessels and Means
for Operating them.
I, DAVID MOFALL, of No. 213 East 35th Street, in the City and State of New York,
United States of America, Boat Builder, 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:-
It has for its object to provide a simple, inexpensive and effective center-board rig
which will strengthen instead of weakening the hull; allows the center-board to be
quickly set and removed as sailing conditions and emergencies may require; and
obviates the necessity of the cumbersome trunk in the hold of the vessel required to
enclose the pivotted center-board in common use.
The invention consists in certain novel features of construction and combinations of
parts of the center-board rig, all as hereinafter fully described and claimed.
Reference is to be had to the accompanying drawings, forming a part of this
specification, in which similar letters of reference indicate corresponding parts in all
the figures.
Figure 1 is a side view of a vessel to which my improved center-board and
operating devices are applied, the mast and sail of the boat being shown only in part.
Fig. 2 is a detail, vertical sectional elevation, in larger size, of the center-board
supports and part of the board and vessel. Fig. 2a is an enlarged detail view of the
screw-joint between the center-board and one of its supporting rods. Fig. 3 is a
transverse sectional elevation taken on the line, of Fig. 2. Fig. 4 is a plan view
of the port-side of the stern of the vessel. Fig. 5 is a transverse section through the
hull of the vessel, and illustrates also the manner of staying the tubular supports of
the center-board rods; and Figs. 6 and 7 show modifications of the invention, and
will be hereinafter particularly referred to.
The hull A of the vessel may have any size and model suitable for a center-board
boat. At the center-board the vessel's keel is shown made in two parts, a a¹, between
which the side planks, a³, of the hull are or may be held, as in Figs. 3 and 5, and to
the lower part, a, of the keel there is fixed a metal shoe or plate, B, which has a
longitudinally-ranging slot or groove, b, in its lower face, in which slot the upper edge
of the center-board C fits snugly.
Hollow metal plugs D D, each having a fixed collar or shoulder, d, at its lower end,
are passed upward through the keel of the vessel, and the upper ends of these plugs
are screw-threaded externally to receive a screw-collar or nipple, E, which, when
screwed home, draws the shoulder d of the plug D tightly to the bottom of the keel,
and also clamps the two parts a a¹ of the keel together, and all with water-tight joints,
which prevents leakage into the vessel around the center-board supports. The
screw-collars E project above the plugs D.to receive the lower threaded ends of
tubes F, (shown only in Figs. 1, 2, 2*, 3, and of the drawings,) said tubes F being
only long enough to give substantial lateral support to rods GG, the lower ends of
which are screwed into head pieces or thimbles cc, which are fixed to the upper edge

page_text: of the center-board. These thimbles c have shoulders or collars c', which fit tightly
to the lower ends of the plugs D when the center-board is in place.
To the tops of the rods G G, there are attached chains or ropes H H, which are
guided over blocks h h, journalled to arms or brackets h¹, fixed to the heads of the
tubes F, and these chains both are carried backward within easy reach of the helmsman,
as indicated in dotted lines in Fig. 1, suitable cleats being provided to which the
ropes may be fastened by the helmsman when the center-board is in place for service
to hold it there.
A chain or rope, I, is attached to the upper rear part of the center-board C and
extends to and over a block, j, on the arm of a crane, J, which is hung in eyes or
staples fixed to the stern of the vessel. (See Figs. 1 and 4.) From the block; the
chain I extends forward to the helmsman who fastens it to a conveniently-located
chock on the boat. If preferred, a second chain or line K, may be attached to the
forward end of the center-board and be carried forward and through a block k, on the
vessel's bows, and thence rearward to the helmsman, to be fastened by him like the
chain I. The object of these chain-connections I K, is to allow the center-board to be
hauled aboard ship, as hereinafter more fully explained. The crane J is not in the
way of the vessel's rudder L or rudder-arm 7. When the crane J is out of use, it
may be swung around to the stern of the vessel, as indicated in dotted lines in Fig. 4
of the drawings.
Stay-rods M, connected to collars m, fixed to the tops of the tubes F F and to the
sides of the hull of the vessel, firmly brace the tubes against leaning over in any
direction and also brace the boat, and these rods M may have turn-buckles m¹ for
∙straining them up tightly at any time required.
The above detailed description refers more particularly to Figs. 1 to 5, inclusive, of
the drawings, and to which only the next following statement of the operation of the
center-board will apply.
We will suppose the center-board C is set for use as in Fig. 1 and held by the
chains H H. Should the helmsman wish the vessel to drift or make leeway with the
tide or current, he will unfasten the chains H and let the center-board fall away some
little distance from the keel of the vessel, and thus become inoperative, and to set the
board again for service the helmsman will draw the chains H up again to enter the
rods Ginto their tubular guides D F, and draw the center-board snugly to the keel-
shoe B and make the chains fast to the chock as at first. Should the center-board
run hard aground and hold the boat fast, the rods G will be unscrewed by the
helmsman from the center-board thimbles c, leaving the boat free, whilst the center-
board may be hauled up on board either amidships or astern. The center-board may
be quickly and easily set again when the boat is free, or a new center-board be placed
in position in place thereof if the detached board is not recovered, by dropping the
rods GG, with float lines attached, through the tubular supports F, D, into the water
and, after picking them up again astern, screwing them once more into the center-board
thimbles. The center-board will then be in readiness to be hauled back under the
vessel by the chains H H, attached to the rods and which have been run out through
the tubular supports F D. By hauling up said chains H H, the rods G G will be
made to enter the tubes F D, and the center-board be thereby drawn up to the keel
when it may be made fast by securing the chains H. to the chock.
If at any time the center-board is not needed, the helmsman will slack off the
chains H, and the center-board will fall from the keel, and may then be pulled aştern
by hauling on the chain I, to lift the center-board by the crane J, and the board may
then be lifted into the boat. If the chain K be connected to the center-board, the
board may be hauled by it at the vessels bows, or amidships.
In the modification shown in Fig. 7 of the drawings the screw-rods G and thimbles c
are substituted by stems N, fixed to the center-board C, and having tapering heads n
fitting tapering recesses or sockets made in the plugs D, the chains H in this case
being connected directly to the heads n, and the tubes F serving as guides to the
chains which run aft, as hereinbefore described.
In the modification shown in Fig. 6 of the drawings the plugs D, collars E, and

page_text: tubes F are made somewhat larger in diameter than corresponding parts in Fig. 2, and
extra tubes, O, are placed within the tubes F and plugs D. The lower ends of
tubes O are screw-threaded, to engage threaded stoms p on head-pieces P, fixed to the
center-board. The tops of these tubes O have collars o¹, having apertures to receive
a bar, by which the tubes may be turned for screwing the stems p up into the lower
ends of the tubes, and thereby drawing the top of the center-board snugly to the keel-
shoe B after the board has been drawn by the chains H, which are connected to the
screw-stems of the center-board and run through the tubes 0. In this instance the
tubes F are passed downward through a deck or seat plank R, and have top shoulders
or collars, f, which are clamped tightly to the plank R, when the tubes.are screwed
home in the collars E, connecting them with the keel-plugs D. The center-board
guides in this case are held securely at top and bottom without the aid of braces M.
Should the center-board run hard aground, the tubes O will be unscrewed from the
center-board stems p, and the chains or lines H will be slackened, and the center-
board will then be hauled up at the stern or bow by the chains, and the chains may be
detached from the board, and floats may then be connected to the ends of the detached
chains, which will be drawn up through the tubes O, until the floats close the bottom
of the tubes, and no chains or lines will be left dragging in the water.
It is obvious that a center-board, made and fitted to a vessel, as above described, can
be set or removed readily, and the trunk enclosing the common pivotted center-board
is dispensed with, and the keel of the vessel is not weakened, and the vessel is not so
liable to leak as when the trunk is used. Furthermore, the improved center-board rig
is not expensive, and may be fitted to vessels of any size.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is :—
1. In center-board rigs, the combination, with the vessel and center-board, of a yoke
or plate on the vessel-keel, and provided with a longitudinal slot in its lower face,
guide rods or pins held to the top of the center-board, guides on the vessel to receive
and support said rods or pins, and chains connected to the rods or pins, and adapted
to draw the center-board within the keel-yoke slot, substantially as described, for the
purposes set forth.
2. In center-board rigs, the combination, with the vessel A and center-board C, of
hollow plugs D D, fitted in the vessel's keel, and provided with collars or shoulders d
and screw-threaded at their upper ends, nuts or collars as at E, screwed to plugs D
above the koel, to clamp its timbers together and hold the plugs to place, rods or pins
on the center-board entering the plugs D, and chains connected to said rods or pins
and adapted for operation of the center-board, substantially as shown and described.
3. In center-board rigs, the combination with the vessel A and center-board C,
provided with screw-threaded stems c c, of rods G G, supported in guides on the
vessel, and screwed at their lower ends to the stems c, c, substantially as described, for
the purposes set forth.
4. In center-board rigs, the combination, with the vessel A, and center-board C,
having guide-rods G, of hollow plugs D, set in the vessel's keel, and provided with
lower shoulders or collars, d, screw-collars E on plugs D, above the keel, tubes F,
screwed to collars E as upper guides to the rods G, and chains H, connected to rods G
and adapted for operation of the center-board, substantially as shown and described.
5. In center-board rigs, the combination with a vessel A, and center-board C, fitted
with guide rods or pins, and tubular guides in the vessel for said rods or pins, of
stay-rods or braces M, connecting the rods to each other and to the vessel, substantially
as shown and described.
Dated this 21th love of Moral 1007