Boom vang for sailing vessel

Ships – Spars – Gaffs – booms – etc.

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C114S090000, C114S218000

Reexamination Certificate

active

06520103

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to an adjustable boom vang for a sailing vessel.
BACKGROUND OF THE INVENTION
A sailboat boom vang is an adjustable device or mechanism secured between an intermediate portion of the mainsail boom and a location near the base of the mast. The forward end of the boom is connected to the mast and normally extends at right angles to the vertical mast. In other words, the boom generally rotates in a substantially horizontal plane about the mast. The leading edge of the mainsail is connected to the mast, and the foot of the sail is connected to the boom. Typically, the boom is connected to the mast by a swivel joint, allowing the rear part of the mast to be raised upwardly. The vang generally forms a triangle with the base of the mast and the boom.
A typical vang includes, especially for smaller boats, a multiple purchase block and tackle system including two or more blocks or pulleys attached to the boom, and a single line having one end secured to one of the pulley systems, with the line having a free end which is pulled out and released manually by the sailor. Especially when sailing downwind, air pressure against the mainsail causes the end of the boom to rise, absent any constraint. The vang may be adjusted to lower or adjust the angle of the boom and to control the shape of the sail, especially the trailing edge of the sail.
In the case of many small sailboats, the mast is unstayed, in that there is not external standing rigging to support the mast in an upright vertical position. In such cases, the base of the mast may extend into a reinforced well or pocket in the deck of the boat and is free to rotate around its longitudinal axis, as the boom rotates away from the centerline of the boat, without allowing the mast to tilt from a vertical position. One commercial example of such a sailboat is known as the Laser.
In most multiple purchase vang systems, a releasable cam cleat is provided at the base of to the system in the exit path of the control line, with the free end of the control line being led aft to the cockpit for control by the sailor. A cam cleat comprises a pair of opposed spring loaded jaws which grip the line and prevent it from slipping against the direction of load, or toward the boom. Cam cleats are conventional items, well known to those skilled in the art of sailing. The line can be released between the jaws by lifting the line upwardly and engaged by pulling on the line. One type of especially suitable cam cleat is described in U.S. Pat. No. 4,453,486, assigned to the Harken Inc., incorporated herein by reference. The line can be released by manually raising the line out of engagement between the jaws and can be engaged by lowering the line under tension against the jaws.
FIG. 1
shows a prior art example of a multi-purchase block and tackle system
10
employed as a boom vang between the base of a vertical mast
12
and a horizontal boom
14
with the boom being connected to the mast by a swivel joint
16
. The vang
10
is connected to the base of the mast
12
and extends rearwardly and upwardly, with the upper portion being connected to the boom
14
and forming a triangle therebetween. The vang
10
comprises a lower multiple part block system
17
connected to the mast
12
and an upper multiple block system
18
connected to the boom. The bitter end
20
of a line
22
is secured to a stationary part of one of the blocks at
23
and is reeved between the block systems
17
and
18
to provide a mechanical advantage when pulling on the free end
24
of the line
22
, and in the example shown, is a four to one ratio or
5
mechanical advantage. The line
22
exits the lower block assembly
16
in alignment with a cam cleat
26
secured to the assembly having opposed jaws which are spring loaded to a closed position to grip the line against the direction of load, or toward the vang. Lower block
17
is attached to the mast by clasp
28
or other loose linkage. Additional blocks and longer lines provide higher ratios as may be desired. Examples of vang systems and component parts for small boats are shown on page 193 of the Harken Inc. 1999 catalog, available from Harken Inc., Pewaukee, Wis.
It may be seen that if the mast
12
and/or boom
14
rotates away from the center line of the boat, as generally illustrated in the plan view of
FIG. 2
, this will cause twisting of the lower block system
16
and the associated cam cleat
26
, such that the free end
24
of the line
22
is out of alignment with the center line between the jaws of the cam cleat. Also, when the vang system is slack, or when load conditions are variable, the cam can move around at an angle to the direction of pull on the line
24
. It will be appreciated that boom vangs of this nature can utilize up to a 8 or 9 to 1 ratio, and the forces involved are very substantial. These conditions can make it difficult or impossible for a single sailor, who is steering the boat with one hand, to release and engage the line
24
with the cleat
26
. Block
17
may twist or flex as line
24
is pulled on, making re-engagement with cleat
26
impossible. Additionally, movement of block
17
off the centerline of the boat as line
24
is pulled on can cause tangling of the line.
It will be appreciated that this problem exists not only for vangs used with unstayed masts that rotate with the boom, but also for stayed masts that remain stable while the boom pivots away from the boat center line. For these stable masts, the lower vang block will twist and turn in the direction of the pivoting boom, making engagement of the lead line with the block cam cleat difficult or impossible. Additionally, drawing on the lead line will tend to cause the lower vang block to twist away from the boom, sometimes resulting in a tangling of the reeved vang line.
There is thus a heretofor unresolved need in the art for a boom vang system with improved performance when the system is at an angle to the centerline of a boat.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a vang base having a rigid tang and a pivotally movable cam arm.
It is a further object of the invention to provide a boom vang system having a rigid tang and a pivotally movable cam arm.
It is a further object of the invention to provide a boom vang system having a rigid tang hingedly attached to the mast, with a cam cleat arm hingedly attached to the rigid tang.
SUMMARY OF THE INVENTION
The present invention comprises a vang base for attachment to a sailboat mast; with the vang base comprising a rigid tang for attachment to the mast and a cam cleat arm pivotally attached to the tang, with the cam cleat arm pivotal along an arc about the base. The tang has at least a pulley attached thereto, and the cam cleat arm has at least a cam cleat attached thereto. In a preferred configuration, the tang further comprises an adjustable jaw arm having a jaw, with a pin held in the jaw. The pivotal cam cleat arm further has an ear for pivotal attachment to the pin.
The present invention additionally comprises a boom vang system having at least a boom pulley for attachment to the boom, and a vang base for attachment to the mast. The vang base comprises a rigid tang for attachment to the mast, the tang having at least a pulley, and a cam cleat arm pivotally attached to the tang, the cam cleat arm rotatable along an arc about the tang. Preferably, the cam cleat arm is pivotal along an arc that lies in a plane that is substantially parallel with the boat deck. A cam cleat is attached to the cam cleat arm. A rope having two free ends passes through the cam cleat, through the tang pulley, and through the boom pulley, with one of the two ends connected to one of the boom or the mast.
In an additional embodiment of the invention, a boom vang's rigid tang is hingedly attached to the mast. The hingedly attached rigid tang has a pivotal cam cleat arm. It will be appreciated that this embodiment of the boom vang of the invention will be of utility for boats having a stayed, stationary mast.
Rather than securi

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Boom vang for sailing vessel does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Boom vang for sailing vessel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Boom vang for sailing vessel will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3171034

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.