Improvements in Movable Keels or Centreboards for Sailing Boats, Yachts and the like.
Year: 1899

page_text: Date of Application, 29th Mar., 1899
Complete Specification Left, 14th Nov., 1899-Accepted, 16th Dec., 1899
PROVISIONAL SPECIFICATION.
Improvements in Movable Keels or Centreboards for Sailing Boats,
Yachts and the like.
I, ALFRED ELEY PRESTON, of St. George's Island, Looe, Cornwall, Ċivil
Engineer, do hereby declare the nature of this invention to be as follows:-
-
This invention for improvements in movable keels or centreboards for sailing
boats, yachts and the like relates more especially to movable keels or centreboards
of the class in which the weight is connected by links to the fixed keel of the
boat so that it can be raised or lowered according to the depth of keel required;
and has for its object an improved construction whereby, while still permitting
of the folding up action of the links, the effective surface of the keel is closed
in to give a greater grip upon the water, the mechanism for effecting this being
simple in character and easy of operation.
According to this invention, the movable keel is constructed in two principal
parts or sections pivotted at a suitable distance apart to the fixed keel or centre-
board case of the boat. At their lower ends these portions are pivotted so as
to carry the weight, the distances between the centres being equal so as to
permit of a folding up action while the weight will be always parallel to the
bottom of the boat:
These sections are so shaped that together they cover the whole surface of the
movable keel, one section being wide while the other is comparatively narrow.
Preferably this narrow section is double so that as the movable keel is raised
and the sections fold up on one another the larger section passes between the
two narrower sections.
It will therefore be seen that the whole effective area of the movable keel is
filled up when it is lowered into place and a greater grip upon the water is
obtained while retaining all the advantages of this class of movable keel or centre-
board.
The upper ends of the keel sections are carried up into a centreboard case and
are connected together by means of a link; and suitable windlass, lever, or other
gear, is arranged so that the keel sections can be moved to raise or lower the
weight in the water. By this arrangement it is ensured that the keel sections
shall move together and as all are operated from above straining of the joints
which would result if the lifting mechanism were applied only to one section,
is greatly lessened.
When in the raised position the keel sections are received within the centre-
board casing. Means are preferably provided by which the movable keel cau
be secured so as to give any desired depth of keel. When raised the weight is
towards the stern of the boat, and this is found to be a great advantage.
Dated this 29th day of March 1899

page_text: Improvements in Movable Keels or Centreboards for Sailing Boats,
Yachts and the like.
I, ALFRED ELEY PRESTON, of St. George's Island, Looe, Cornwall, Civil
Engineer, 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:-
This invention for improvements in movable keels or centreboards for sailing
boats, yachts and the like relates more especially to movable keels or centreboards
of the class in which the weight is connected by links to the fixed keel of the
boat so that it can be raised or lowered according to the depth of keel required,
and has for its object an improved construction whereby, while still permitting
of the folding up action of the links, the effective surface of the keel is closed
in to give a greater grip upon the water, the mechanism for effecting this being
simple in character and easy of operation.
According to this invention, the movable keel is constructed in two principal
parts or sections pivoted at a suitable distance apart to the fixed keel or centre-
board case of the boat. At their lower ends these portions are pivoted so as
to carry the weight, the distances between the centres being equal so as to
permit of a folding up action while the weight will be always parallel to the
bottom of the boat.
These sections are so shaped that together they cover the whole surface of the
movable keel, one section being wide while the other is comparatively narrow.
Preferably this narrow section is doubled so that as the movable keel is raised
and the sections fold up on one another the larger section passes between the
two narrower sections.
It will therefore be seen that the whole effective area of the movable keel is
filled up when it is lowered into place and a greater grip upon the water is
obtained while retaining all the advantages of this class of movable keel or centre-
board.
The upper ends of the keel sections are carried up into a centreboard case and
are connected together by means of a link and suitable windlass, lever or other
gear is arranged so that the keel sections can be moved to raise or lower the
weight in the water. By this arrangement it is ensured that the keel sections
shall move together and as all are operated from above straining of the joints
which would result if the lifting mechanism were applied only to one section
is greatly lessened.
When in the raised position the whole or greater part of the keel sections
are received within the centreboard casing. Means are preferably provided by
which the movable keel can be secured so as to give any desired depth of keel.
When raised the weight is towards the stern of the boat, and this is found to he
a great advantage.
In order that this invention may be more clearly described reference is had to
the accompanying sheet of illustrative drawings on which
Fig. 1 is an elevation of a boat provided with a movable keel constructed
according to this invention the keel being shown in its lowered position while
its position when raised is indicated in broken lines.
Fig. 2 is an end view of the boat and
Fig. 3 is an underneath plan of the same.
The keel is constructed of three sections A, and B, and B' the two sections B, B¹

page_text: being duplicates of one another and constituting for all practical purposes one
section only. There is a space between the sections B B into which the section A
can pass when the sections are folded upon one another as will be hereinafter
described.
The section A. is pivoted at a to the fixed keel C¹ or to the centreboard case
of the boat C and the sections B B¹ are pivoted at 6 the pivots a and b being
a suitable distance apart. At their lower ends the sections are pivoted at a¹
and to the weight D. The distances between the pivots a band a¹ are
equal and the distances between the pivots a a¹ and bb being also equal it will
be seen that when the sections are folded upon one another as will be hereinafter
described the weight D will always be parallel to the fixed keel or centreboard
case of the boat.
The sections A and B B¹ are so shaped that together they cover the whole
surface of the movable keel which is therefore practically a single plate. The
section A is of considerable size while the sections B B¹ are comparatively
narrow.
When the greatest area of the movable keel is required the weight D is allowed
to take its lowest position and the sections A B B extend downwardly. The
effective area of the movable keel is then filled up and the required grip upon
the water thus obtained. If the movable keel is not required at its extreme
depth it can be lowered to the necessary distance and the weight D will still be
in a position parallel to the boat and the whole area of the keel is still filled up.
Moreover as the weight D is raised it takes a position further towards the stern
of the boat a feature that is in accordance with practical requirements.
As the weight D is raised the section A passes between the two sections B B¹.
In order to raise or lower the sections A B B¹ the upper ends A2 B2 are carried
up into the centreboard casing E and are connected together by means of a
link F. In the arrangement shown a winch G is connected by a wire rope to
the extension A2 and provides a means for turning it through the angle necessary
to raise or lower the section A to the extent required and this movement is
communicated by the link F to the extension B2 thus moving the sections B B₁
similarly to the section A and raising or lowering the whole of the movable keel
to the required extent. Any other suitable mechanism such as lever or other
gear may be employed to operate the extensions A2 B². By the arrangement
described it is ensured that the keel sections shall move together and as all are
operated from above, straining of the joints which would result if the lifting
mechanism were applied only to one section is greatly lessened.
A sector rack or pin mechanism may be employed to retain the winch mechanism
G in any desired position thus keeping the weight D at the required depth.
When the weight D is completely raised the whole or the greater part of the
sections A B B are received within the centreboard case the weight D being
towards the stern of the boat.
Although the sections B B₁ are described it will be at once apparent that one
section only is necessary the two sections being only provided for practical require-
ments. One section therefore only may be used without departing from this
invention.
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) An improved movable keel for sailing boats comprising a weight, keel
sections pivoted to the fixed keel or centreboard case of the boat and to the said
weight the distances between the pivots being such that whatever the position
the weight will remain parallel to the fixed keel or centreboard case of the boat
and the sections being so shaped that the whole effective area of the movable
keel is filled up whatever its position, in combination with means for raising
or lowering said weight substantially as described and for the purposes set forth.

page_text: (2) An improved movable keel for sailing boats comprising a weight, a wide
section pivoted at one end to the fixed keel or centreboard case of the boat and
at the other end to the forward end of the weight, narrow sections pivoted to
the fixed keel or centreboard of the boat at one end and at their other ends
pivoted to the rear end of the weight, the distances between the pivots being
such that whatever its position the weight will be always parallel to the fixed keel
or centreboard case of the boat and the sections being so shaped that the whole
effective, area of the movable keel is filled up whatever its position the wide
section being adapted to pass between the two narrow sections during the folding
up movement,, in combination with means for raising or lowering said weight
and with means for securing in any desired position, substantially as described
and for the purposes specified.
(3) An improved movable keel for sailing boats comprising sections A B B¹
pivoted at a and b to the fixed keel C, weight D, pivoted at, a and b to the
sections A B B¹, extensions A2 B2, link F, winch G, and centreboard casing E
all arranged and operating, substantially as described with reference to the
drawings and for the purposes specified.
Dated this 13th day of November 1899
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.