Ships – Sail or control means therefor – Spinnaker pole
Reexamination Certificate
2001-03-30
2002-07-30
Sotelo, Jesus D. (Department: 3617)
Ships
Sail or control means therefor
Spinnaker pole
C114S089000, C114S174000
Reexamination Certificate
active
06425338
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to improved mechanical systems for handling spinnaker poles as used on sailboats.
BACKGROUND OF THE INVENTION
Numerous patents are directed to various devices for spinnaker poles and related equipment for handling spinnaker sails as used on sailboats, and recognize some of the same difficulties and problems inherent therein as addressed by the present invention.
More particularly, modern sailboats (at least those over some minimal length; smaller boats are generally less sophisticated), and which are intended for relatively high performance, especially for racing (similarly, “cruising” sailboats are commonly less sophisticated), typically “fly” “spinnaker” sails when sailing “off the wind”. That is, when sailing upwind, sailboats typically rely on the combination of a mainsail and one or more jib sails; see, e.g., Keenan U.S. Pat. No. 6,070,545 for discussion of some of the considerations relevant to sailboats when sailing upwind. By comparison, when sailing off the wind, the jib is commonly lowered, and a spinnaker is flown.
A spinnaker may be considered to be a three-sided sail having an upper corner, or “head”, that is hoisted to, or nearly to, the top of the sailboat's mast. All three of the spinnaker's edges are free, creating significant problems of sail control. (By comparison, a mainsail usually has one edge fixed to the mast and a second edge fixed to or closely constrained by a rigid spar, the “boom”, while a jib normally has its leading edge constrained by the headstay of the boat, but two free edges.) As usually employed, one of the two lower corners of the spinnaker is termed the “tack”, and the other the “clew”. As will appear below, the assignment of these terms to the corners of the spinnaker can vary depending on the orientation of the boat with respect to the wind, complicating the precise definition of terms.
Traditionally, that is, over approximately the span of the last century, one of the corners of a spinnaker has been controlled by attachment (typically by way of an intermediary fitting, or a short length of wire rope, or line) to an outboard end of a spinnaker pole. (There are also spinnakers designed to be flown without poles. The invention is not directly relevant to these.) An inboard end of the pole is usually releasably fixed to the mast of the boat at a pivot point; the pivot point is defined by a fitting attached to the mast. Commonly, the mast fitting is mounted on a car, which can be moved by control lines up and down along a track affixed to the forward side of the mast. The car position is thus varied to control the shape of the sail, and the car is also moved up and down to perform a “dip-pole jibe”, as discussed in detail below. The outboard end of the pole is controlled by a number of lines. Typically these control lines include a topping lift, running upwardly to or near the masthead to hoist the outboard end of the pole, a foreguy or downhaul extending down toward the foredeck to prevent upward movement of the pole end, and a pair of guys extending aft on either side of the boat to adjust the attitude of the pole with respect to the longitudinal centerline of the boat.
The corner of the spinnaker adjacent to the outboard end of the pole at any time is termed the tack; the third corner of the spinnaker is termed the clew, and is controlled by a line led aft toward the stern of the boat, termed the sheet. The situation is further complicated (both as to precise definition of terms, and as to smooth sail-handling) by the fact that the attitude of the spinnaker and its connection to the boat by the pole and the various lines mentioned must be altered during sailing, as the boat's attitude with respect to the wind changes.
More specifically,
FIG. 1
shows a sailboat
10
on “port tack”, that is, with the wind W blowing over the left or “port” side of the boat. As shown, mast
12
supports a mainsail
14
and a spinnaker
16
, the head
18
of which has been hoisted to the masthead
20
. The tack
22
of the spinnaker
16
is releasably fixed to the outboard end
29
of a spinnaker pole
26
, the inboard end
27
of which is pivotally attached to mast
12
. As noted above, and as shown in further detail below, the inboard end of pole
26
is affixed to mast
12
at a fitting allowing the pole to pivot freely with respect to mast
12
, and which can be moved controllably upwardly and downwardly along a track
42
affixed to the forward side of mast
12
. A topping lift
25
supports the outboard end of pole
26
; the topping lift typically runs down inside mast
12
to a cleat or other fixing device. A foreguy
32
prevents the pole tip from unrestrained upward motion. Tension in a guy
36
and in the spinnaker itself adjust the angular position of the pole with respect to the centerline of the boat. A sheet
28
controls the clew of the spinnaker. A headstay
30
and a backstay
40
brace mast
12
fore and aft; shrouds on either side (not shown) provide lateral support for the mast.
The manuever undertaken when it is desired to change the attitude of the boat with respect to the wind so that the wind W comes over the right rear, or “starboard quarter”, of the boat is called a “jibe” (sometimes “gybe”); jibing the boat from its attitude in
FIG. 1
therefore involves turning it rightwardly through 45° or more. As part of this manuever, the spinnaker and pole must be controlled to assume the corresponding positions on the new starboard tack. In the spinnaker jibing procedure most pertinent to the present invention, the outboard end
29
of pole
26
is detached from the present tack
22
, the pole is swung across the bow of the boat so that its end is disposed over the starboard side of the bow, and the outboard pole end
29
is attached to the present clew
24
, which becomes the new tack. (In a so-called end-for-end jibe, practiced mostly with respect to smaller boats, the inboard end of the pole is detached from the mast and affixed to the new tack; the original outboard end of the pole is then detached from the former tack and affixed to the mast).
In simpler rigging schemes, mainly applicable to smaller boats, the line which forms the present guy
36
then becomes the sheet, while the present sheet
28
becomes the new guy. In the rigging arrangement commonly used on larger boats, pairs of both sheets and guys are provided, so that the lines used and their fittings can be optimized for the loads encountered. The extra sheet and guy are not shown in
FIG. 1
, to avoid complication. In the usual terminology, the “lazy” sheet becomes the “working” sheet upon jibing; the guys similarly change status and name upon jibing.
A number of US patents which provide background for the present invention are directed to devices for simplifying the process of disconnecting the end of the pole from one corner of the spinnaker, reconnecting it to the opposite end, and for interchange of the lazy and working sheets and guys. See generally McAlpine U.S. Pat. No. 5,347,945, Nilsen U.S. Pat. No. 3,185,121, Aronowitsch U.S. Pat. No. 4,473,021, Wasowski U.S. Pat. No. 5,333,566, Klein U.S. Pat. No. 5,558,035, Tiesler U.S. Pat. No. 6,085,679, Hall U.S. Pat. No. 5,109,786, Moseley U.S. Pat. No. 3,207,114, and Ridder U.S. Pat. No. 3,228,372. Smith U.S. Pat. No. 4,164,193, Eglais U.S. Pat No. 4,598,658, Lillehook U.S. Pat. No. 4,773,345, and Murnikov U.S. Pat. No. 5,937,779 are also generally relevant to the various problems encountered in control of spinnakers and other sails on sailboats.
As noted, most of the cited art is directed to the problem of interchanging the sheets and guys, and disconnecting the pole end from one corner of the sail and connecting it to the other corner. A concern which is less often addressed but also very significant is the control of the pole itself. Although spinnaker poles have grown increasingly lightweight in recent years, thanks to the availability of sophisticated materials such as epoxy-impregated carbon and “Kevlar” fibers, they are still large and unwieldy, and can
Angeli Michael de
Sotelo Jesus D.
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