U.S. patent number 3,795,215 [Application Number 05/247,135] was granted by the patent office on 1974-03-05 for mast structure.
Invention is credited to Frank W. Butler.
United States Patent |
3,795,215 |
Butler |
March 5, 1974 |
MAST STRUCTURE
Abstract
Herein described is a sailboat mast which is elongated to carry
a sail thereon. The mast in the cross-section view is shaped having
a transverse section thinner than the longitudinal section. It is
positionable in the sailboat with the thicker longitudinal section
being positioned on the port and starboard side of the sailboat,
and with the thinner transverse portion of the cross-section
positioned fore and aft of the sailboat. The sail track is
positionable on the mast in the section towards the aft part
centered in the substantially center of the thinner portion of the
mast.
Inventors: |
Butler; Frank W. (Westlake
Village, CA) |
Family
ID: |
22933713 |
Appl.
No.: |
05/247,135 |
Filed: |
April 24, 1972 |
Current U.S.
Class: |
114/90 |
Current CPC
Class: |
B63B
15/0083 (20130101) |
Current International
Class: |
B63B
15/00 (20060101); B63b 015/00 () |
Field of
Search: |
;114/90,39,122 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reger; Duane A.
Assistant Examiner: Basinger; Sherman D.
Attorney, Agent or Firm: Geauque; Robert E.
Claims
Having thus described on preferred embodiment of this invention
what is claimed is:
1. In combination with a sailboat, said sailboat having a bow and a
stern, said sailboat having a mast, said mast being an elongated
hollow, thin-walled rigid member, the improvement comprising:
said mast being completely encased to form a unitary structure,
said mast having a basic oblong configuration, in cross-section the
bow to stern length of said mast being less than the starboard to
port length of said mast, and
the amount of curvature of the bow side of said mast being greater
than the amount of curvature of the stern side of said mast,
whereby said mast is more readily bendable in the stern direction
than in the bow direction.
2. The mast as defined in claim 1 including:
a forestay coupled between the bow of said sailboat and said mast,
said forestay coupled to said mast at approximately one-half the
length of said mast, said forestay to control the amount of bending
of said mast in the stern direction.
3. The combination as defined in claim 2 including:
a guide track connected to said mast substantially at the center of
the stern side of said mast and extending the entire length of said
mast and having an opening therein across the entire length of said
guide track, whereby a rope is to be conducted through said guide
track and the sail is to be connected to said rope and movable to
an extended position by said rope with a portion of said sail
passing through said opening.
4. The combination as defined in claim 3 wherein:
said guide track being substantially circular in cross-sectional
configuration.
5. The combination as defined in claim 3 wherein:
said guide track being substantially rectangular in cross-sectional
configuration.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to mast and more particularly to a novel and
improved mast used in sailboats which provides for bending in the
fore and aft directions and substantially rigid in the athwartship
directions.
2. Discussion of the Prior Art
Recently it has become very popular to construct sailboat masts of
aluminum or other lightweight material whereby the masts are
extruded in the manufacturing thereof. It has been found that these
lightweight materials used in the construction of masts are quite
easy to handle and generally a single person can raise and lower
the mast on the sailboats with ease. That aluminum or other
lightweight materials as well-known are quite flexible and
therefore it is found necessary that the amount of bend in the mast
be controlled. Preferably the bend of the mast should be always in
the fore and aft direction and rigid in the port and starboard
direction. In order to limit the bend in the desired direction a
pair of shrouds have one end coupled a portion of the way up the
mast and the other ends of the shrouds are connected to the port
and starboard side of the sailboat.
The reason it is desirable that the mast bend in the fore and aft
direction is so that it will contour to the shape of the sail as
the sail is filled with air.
Prior art sailboat masts have a track along the lengthwise
direction so that the sail can be inserted in the groove and raised
and lowered up and down.
These prior art devices have normally been heretofore constructed
in many shapes and forms with some having a thickness when viewed
in cross-section thereof being in the fore and aft direction. The
track therein, has heretofore been at the very apex of the mast.
Generally speaking the track is extruded into the mast during the
manufacture thereof. In some cases the track provided includes
circular shaped portion sometime constructed inside the mast with
an opening or track along the tip edge of the apex of the mast so
that the sail can extend through the opening. A rope is sewed into
the sail, for example, and positioned into the entire track. Thus
suitable means are provided for raising and lowering the sail by
means of this track. This is generally done with a pulley
positioned at the top of the mast and a line leading from the
bottom of the boat to the top of the mast.
Other types of arrangements have been used whereby a sock is
provided on the sail and it is fitted directly over the top of the
mast. The reason for this is that the mast thus can be made into
two sections with a thicker section at the bottom of the mast and a
thinner section at the top of the mast to allow for the bending at
the top thereof in a manner aforesaid.
Difficulties in all of the above-mentioned prior art masts is that
there is a necessity for shrouds on the fore and aft sides of the
sailboat which may hamper the the mobility of the person sailing
the boat. The purpose of the shrouds is to restrict sideways
bending of the mast. Another difficulty in the prior art device is
that there is no way in which the bend of the mast can be
controlled especially in the bending to the aft direction.
SUMMARY OF THE INVENTION
The present invention overcomes the difficulties of the prior art
device in that for example, it does not require shrouds. Further,
the present invention because of its unique construction will not
bend in the port and starboard directions but it will bend in the
fore and aft directions, thus allowing the mast to bend in the aft
direction and better fit to the contour of the sail.
The control of the bend of the mast is provided in this the
described embodiment of this invention by a small forestay which is
adjustable to be attached approximately a preselected way up the
mast. By proper selection of the position of the attachment and
adjustable fitting, the bend of the mast can be controlled.
Briefly describe the present invention provides a mast being
substantially oblong in the cross-section thereof with the apexes
of the oblong shape being positionable in the boat in the port and
starboard sides thereof. Thus the thickness of the oblong will be
athwartship with the cross-section thinner in the fore and aft
directions to allow for easy bending in these directions. A track
provided along the length of the mast for the raising and lowering
of the sail. The track positioned in the thinner portion of the
cross-section and being substantially centered therein so that the
sail can be raised up and down the mast. A small forestay is then
coupled to the fore portion of the sailboat and other end of which
is coupled halfway up the mast.
DESCRIPTION OF THE DRAWINGS
These and other features and advantages will become more apparent
to those skilled in the art when taken into consideration with the
following detailed description wherein like reference numerals
indicate like and corresponding parts throughout the several views
and wherein:
FIGS. 1 and 2 are cross-section view of certain masts used in the
prior art;
FIGS. 3a and 3b are cross-section views of masts in accordance with
the principles of this invention;
FIG. 4 is a view of a sailboat employing the masts of this
invention;
FIG. 5 is a section view of the invention of the sailboat taken
along the lines 5--5 of FIG. 4.
DESCRIPTION OF ONE EMBODIMENT
Referring now specifically to FIGS. 1 and FIGS. 2 there is shown
prior art illustrations of cross-sections views illustrating shapes
of extruded masts. These are only illustrative of the prior art and
there are many other types of masts involved. It should be noted
that they are either circular in shape as for example the one in
FIG. 1 or oblong in shape as shown in FIG. 2. These prior art masts
are constructed preferably of lightweight material such as aluminum
so that they are light to handle. But in order to be flexible in a
desired position some of the prior art mast shown in FIGS. 1 and 2
must be tapered in shape with the thicker portion of the taper is
that portion that is connected to the hull of the boat, and the
thinner portion of the taper being near the top of the mast so that
they can bend and contour the sails.
A problem arises with the mast that is flexible is that it is
flexible in all directions. For example, a mast that is tapered and
of the configuration shown in FIG. 1 and 2 as examples the mast
will not only bend in the fore and aft direction, the desired
direction, but also in the port and starboard direction or
athwartship direction. This port and starboard bending is
undesirable and it is necessary to connect a pair of shrouds on
either side of the mast a portion of the way up, and connected to
the port and starboard side of the sailboat. Primarily this is done
for the purpose of preventing bending in this direction.
Unfortunately though the top portion of the mast will continue in
all directions and sometimes in the undesirable directions.
Means are included in the mast to provide a track for the sail to
be lowered and raised on the mast. FIG. 1 for example has a
somewhat triangular shaped guide 10 which has an opening 12
thereof. A rope which is connected into the sail fits into the
track 10 while the sail is allowed to extend through the opening
12. As the rope is drawn up the track 10 the sail also raises and
lowers through the opening 12. FIG. 2 has similar track 10a and an
opening 12a but in this particular invention embodiment is shown as
being a circular track to better fit the rope which is normally
sewn into the sail.
Primarily the mast is hollow in shape and provides for easily
extrusion construction methods. FIG. 1 shows it circular while FIG.
2 shows it oblong with the apex 14a of FIG. 2 being positionable in
the boat towards the forward direction thereof. The track 10 and
the openings 12a being on the other apex of the oblong section and
positionable towards the aft position of the sailboat.
The particular embodiments of FIG. 1 and 2 will provide that there
will probably be a restriction to fore and aft bending because of
the shape of the mast. While FIG. 1 will provide bending in fore
and aft direction a little bit more easier than that in FIG. 2 but
in other case there will also bend in the port and starboard
direction which is undesirable.
The present invention overcomes the difficulties by providing the
configuration in a novel arrangement as set forth in FIGS. 3a and
3b. Like the prior art devices in FIGS. 1 and 2, a track 10b and
10c is provided in the mast with the similar opening in 12b and 12c
for the same purposes as provided in the prior art and that is to
guide the sail up and down the length of the mast. But a
distinction in the mast showed in FIGS. 3a and 3b is provided to
overcome the aforesaid difficulties in bending. The mast
cross-section FIG. 3 is shown with being oblong or semi-oblong in
shape with the apexes 14b and 15b being on the port and starboard
side of the sailboat. This is best shown in the section view of
FIG. 5. With this particular shape, bending is restricted in the
port and starboard directions because of the thickness of the mast
in this direction. But because the mast is thinner in the fore and
aft direction, bending is allowed in this direction.
It is to be noted by referring in particularly to FIGS. 3a and 3b
that the curvature of the mast in the fore (or bow direction) is
greater than the curvature of the mast in the aft (or stern
direction). The greater the curvature, the more difficult to bend
the structure in the direction of the curvature. As a result, the
mast of this invention is more difficult to bend in the bow
direction than to bend in the stern direction. As previously
mentioned, it is not preferred to have the mast bend toward the
bow, but it is desirable to have the mast bend a limited amount in
the stern direction responding to gusts of wind.
It should be understood that it would be preferable to control the
bending in the fore and aft direction so a small forestay 16 shown
in FIG. 4 is connected half way up the mast 8 by suitable means and
the other end of the forestay 16 is connected to the very bow of
the sailing vessel.
FIG. 3b shows an alternate embodiment of this invention defining
the track 3c on the outside of the mast itself and in the form of
two L-shaped protrusions. The rope in the sail is on the inside of
the track 10c and the opening 12c is defined between the two
L-shaped protrusions.
Thus there has been described a new and novel improvement in mast
sections which requires no shrouds as opposed to the old style mast
which required such. Further there has been described a new mast
section which bends fore and aft directions but not in the port and
starboard direction, and thus allows the mast to bend aft at the
top to better fit to sail contours. The prior art mast sections
could not bend in this manner. Further there has been described a
mast which only requires one small forestay as compared to the
prior art required at least two shrouds, as well as the forestay.
Thus the bend of the mast can be controlled and prevents the mast
from bending too far aft due to the unusual shape of the mast.
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