Patent Document

RELATED APPLICATIONS 
     This application is related to U.S. application Ser. No. 12/437,076, “Mast Track with External Headboard Car,” and U.S. application Ser. No. 12/437,062, “Sectionalized Mast Track,” both of which are being filed on the same day as the instant application. The subject matter of this application is also related to U.S. Pat. No. 6,371,037, “Sail Furling System,” to Cook et al. filed on Dec. 26, 2000. 
     The above-referenced applications and patent are incorporated herein by reference in their entireties. 
     BACKGROUND OF THE INVENTION 
     Furling and reefing are separate, but related activities involving hoisting and lowering sails on yachts and sailboats. Furling is completely retiring a sail from use so that the furled sail no longer presents any cross section to the wind for driving the boat. Reefing, on the other hand, refers to reducing the sail area to provide less cross section to the wind, reducing the driving force of the wind on the sail. Since most furlers are also used as reefers, the terms are used interchangeably herein. 
     Before the advent of furlers, at least two people were needed to hoist and lower the sails on larger yachts. Prior art furlers are intended to allow a single person to hoist and lower sails on large yachts, even those longer than 40 feet. Many of the first mainsail furlers were mast furlers designed to furl the mainsail within the mast, allowing the lower edge, or foot, of the sail to slide along the boom toward the mast as the sail is furled. Unfortunately, mast furlers increase the weight aloft, affecting the stability of the vessel under sail. Mast furlers are also difficult to maintain, as fixing even simple malfunctions, such as jams, requires someone to go aloft, a dangerous and time-consuming activity. 
     Boom furlers, on the other hand, are configured to furl the sail inside the yacht&#39;s boom, which extends perpendicularly from the mast at the foot of the sail. Depending on the configuration, the foot of the sail may be attached to the mandrel along its length or attached only at the tack and clew (i.e., the forward and aft corners along the foot of the sail). A winding cord attaches the sail to a drum inside the boom. Rotating the drum causes the sail to wind (or unwind) around a mandrel inside the boom. Because the boom furler is close to the deck, boom furlers are easier to maintain than mast furlers and do not affect the stability of the yacht. 
     Unfortunately, most boom furlers must be installed apart from the mast, creating a space between the mast and the furler where the sail deforms. This deformation tends to increase when the sail is wound down, causing folds in the ends of the winding. In addition, this configuration increases stress on the bolt rope, which is sewn into the sail to aid in feeding the sail into the boom or mast. Increased stress on the bolt rope makes it more difficult to wind or unwind the sail. 
     Prior art solutions described in U.S. Pat. No. 5,697,314 to Clausin include using pulleys to offset the drum or relieve stress on the bolt rope. Pulleys introduce friction, making it difficult to wind and unwind the sail; they also require linkages that must remain taut. Clausin also discloses a recessed bolt rope slot and bolt rope guide that relieve stress on the bolt rope. U.S. Pat. No. 4,236,475 to Merry teaches a simpler, two-pronged metal guide for aligning the bolt rope with mast, preventing the bolt rope from jamming as the sail is raised or lowered. Neither of these bolt rope guides is sufficiently strong to handle the stresses of larger sails, such as those used on yachts of 40 feet or more in length. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention include an articulating sail feeder and method for using an articulating sail feeder for a yacht. Example articulating sail feeders include herein called “hinge tracks” arranged in an articulating column with a longitudinal axis substantially parallel to a mast of a yacht, where the hinge tracks are configured to receive a sail luff. Herein referenced “limiting pins” and ball joints in the articulating column enables lateral and rotational movement of the sail. The limiting pins, which are pins disposed between respective pairs of adjacent hinge tracks, limit the movement of a given hinge track with respect to a neighboring hinge track and thus are referred to herein as “limiting pins”. The ball joints, which are also disposed between respective pairs of adjacent hinge tracks, receive a tensioning line that runs along the longitudinal axis of the articulating column. 
     In certain embodiments, the articulating column enables the sail to move and rotate freely in a lateral direction with limited axial twist as the sail is being furled or reefed. This free rotation may be achieved using limiting pins formed of two frustums, or truncated conical sections, that are placed base-to-base and separated by a flange. The slope of the frustums determines, in part, the range of motion and may allow universal axial motion. 
     The articulating column&#39;s range of motion may also be adjusted using the tensioning line, which may be a flexible wire, cable, rod, or synthetic rope. Embodiments of the articulating sail feeder include means for adjusting tension of the tensioning line, such as wrenches or hydraulic cylinders. The means for adjusting tension of the tensioning line may be situated at either end or both ends of the tensioning line. 
     The hinge tracks may have a cross section comprising a batten guide, or luff extrusion, formed of two substantially parallel batten guide arms. A luff passage connects the batten guide to a luff rope slot formed forward of the batten guide. Example luff extrusions may include a channel configured to guide a headboard car along an axis substantially parallel to the long axis of the mast. 
     The articulating sail feeder may be configured to be coupled to a mast track for a yacht, such as a sectionalized mast track. Sectionalized mast tracks may include multiple mast track sections arranged in a column configured to be attached to a mast. Each mast track section may include an upper receiver and a lower receiver, both of which may be oriented along the longitudinal axis of the column. Neighboring mast track sections may be secured using respective securing pins configured to be received by a lower receiver of one mast track section and an upper receiver of the adjacent mast track section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention. 
         FIG. 1  is an elevation view of a yacht employing an example articulating sail feeder of the present invention. 
         FIG. 2  is an elevation view of a mast, boom, and example articulating sail feeder of the present invention. 
         FIGS. 3A and 3B  are, respectively, an elevation view of an example articulating sail feeder and a plan view of a hinge track of the example articulating sail feeder in the present invention. 
         FIG. 4  is a perspective view of a limiting pin used in embodiments of the present invention. 
         FIG. 5  is a perspective view of a ball joint used in embodiments of the present invention. 
         FIGS. 6A-C  include plan and elevation views, respectively, of a hinge track according to embodiments of the present invention. 
         FIGS. 7A and 7B  are plan and elevation views, respectively, of a bottom hinge track of the present invention. 
         FIGS. 8A-E  include different perspective views of a feeder section of the present invention. 
         FIGS. 9A and 9B  are plan and elevation views, respectively, of an external headboard car, headboard, and mast track suitable for use with an example inventive luff extrusion cross section in one embodiment of the present invention. 
         FIG. 10  is a plan view of a hinge track cross section suitable for use with an internal headboard car according to alternative embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A description of example embodiments of the invention follows. 
       FIG. 1  shows a yacht  10  with a mast  20  and a boom  26 . The boom  26  stores a sail  30 , which may be raised with a halyard (not shown) and a headboard car  28  to capture wind and propel the yacht  10 . The headboard car  28  is coupled to a headboard  29  that reinforces the head  38  of the sail  30  to prevent high loads from tearing apart the head  38 . A mast track  24  guides the headboard car  28  and a luff rope (not shown; also known as a sail bolt rope or bolt rope) stitched into the forward edge, or luff  36 , of the sail  30  along an axis parallel to the long axis of the mast  20 . Although the headboard car  28  shown in  FIG. 1  travels along a channel on the outside of the mast track  24 , alternative headboard ears may be configured to travel within a groove internal to the mast track  24 . 
     The sail  30  shown in  FIG. 1  is a fully battened mainsail  30  with battens  32  that run generally parallel to the bottom edge, or foot  40 , of the sail  30  from the luff  36  (leading edge) to the trailing edge, or leech  37 , of the sail  30 . The battens  32  are stitched into batten pockets  34  in the sail  30 . Standard battens (not shown) run only partway from the luff  36  to the leech  37 , trading long-term performance for reduced chafing and easier handling. Battens may be oriented in other directions or combinations of directions; for example, alternative battens may run perpendicularly from the leech  37  to intersect the foot  40  and the luff  36  at substantially complementary angles. 
     Full battens  32  support roach  42 , the sail area that lies outside a straight line from the head  38  to the lower aft corner, or clew  39 , of the sail  30 . Typically, the supporting battens  32  are about three times longer than the roach  42  that they support. Roach  42  enhances sail performance by adding 15-30% more sail area to a triangular sail, such as the sail  30  shown in  FIG. 1 . More importantly, mainsails with roach  42  have elliptically shaped heads and planforms that improve performance on all points of sail, particularly to weather. 
     Unfortunately, full-length battens  32  reduce the life of the sail  30  by chafing against the batten pockets  34 . The same forces that pull the sail  30  taut to propel the yacht  10  push the battens  32  towards the mast  20 , causing the battens  32  to chafe against the batten pockets  34 . Eventually, this chafing causes the battens  32  to tear or poke through the forward ends of the batten pockets  34 . Reinforcing the batten pockets  34  alleviates this problem on vessels with smaller sails, but reinforcement is not sufficient to withstand chafing due to the larger compressive forces exerted on battens  32  in larger sails. In addition, compression increases friction on the sail slides that run in mast tracks  24  and in articulating sail feeders  80  without headboard cars  28 , making it difficult to raise, lower, or reef the sail  30 . 
     An articulating sail feeder  80  coupled to the bottom of the mast track  24  limits the sail&#39;s range of motion as the sail  30  is fed into the boom  26  by a boom furler (not shown), making it easier to reef and furl the sail  30 . In yachts  10  without the present inventive articulating sail feeder  80 , the sail  30  deforms in the space above the boom  26  during winding, causing folds in the ends of the winding. The articulating sail feeder  80  moves with the sail  30  as the sail  30  is being furled or reefed, preventing deformation and relieving stress on the bolt rope (not shown), which is sewn into the edge of the sail  30  to prevent fraying. The articulating sail feeder  80  allows the sail  30  to move and rotate freely from side to side (i.e., laterally), while preventing the sail from twisting too much around an axis parallel to the long axis of the mast  20 . 
       FIG. 2  shows an example articulating sail feeder  80  coupled to the bottom of a mast track  24 . The lower end of the articulating sail feeder  80  is suspended from the mast  20  above the boom  26  to allow free lateral movement of the sail  30  as the sail  30  is raised or lowered using the headboard car  28  coupled to the headboard  29 . Pulling (or releasing) the halyard (not shown) attached to the headboard car  28  causes the headboard car  28  to travel up (or down) a headboard car channel  310 , raising (or lowering) the sail  30 . 
     The articulating sail feeder  80  flexes and twists as the sail  30  is wound down, reducing deformation of the sail  30  and eliminating folds in the ends of the winding. The articulating sail feeder  80  also reduces stress on the bolt rope by flexing and bending, making it easier to wind or unwind the sail  30 . In addition, the articulating sail feeder  80  may be configured to enable limited twist or rotation about an axis parallel to the longitudinal axis of the mast  20  as the sail  30  is furled or reefed. The articulating sail feeder  80  may also flex fore and aft (i.e., in the plane of the page) or abeam (i.e., into and out of the page). 
     A feeder  82  at the bottom of the articulating sail feeder  80  guides the sail  30  into and out of the articulating sail feeder  80 , which includes several track members herein called hinge tracks  84  arranged in a column between the feeder  82  and the bottom edge of the mast track  24 . A threaded tensioning line  86  runs through the hinge tracks  84  along the interior of the column. A nut  88  secures the lower end of the tensioning line  86  in a bottom hinge track  85 . Adjusting the nut  88  changes the tension of the tensioning line  86 , altering the articulating sail feeder&#39;s range of motion. 
       FIGS. 3-6  show various views of an articulating sail feeder  80  and some of its components, including hinge tracks  84 , limiting pins  90 , and ball joints  94 ,  FIGS. 3A and 3B  include, respectively, an elevation view of an articulating sail feeder  80  and a plan view of a hinge track  84 . The articulating sail feeder  80  includes plural hinge tracks  84  arranged in an articulating column  81  like vertebrae in a spine. Limiting pins  90  and balls joints  94  arranged between respective pairs of adjacent hinge tracks  84  limit the motion of the column  81 . 
     As shown in  FIGS. 3A and 4 , each limiting pin  90  is formed of upper and lower truncated conical sections, or frustums  91  and  93 , attached to a flange  92 . The flange  92  separates a respective pair of neighboring hinge tracks  84 , which receive the upper and lower frustums  91  and  93  in respective recesses  340 . In a preferred embodiment, the limiting pins  90  are formed of nylon that has a low coefficient of thermal expansion, high strength, and high rigidity, such as Nylatron GS. Typically, the edges of the limiting pins  90  are beveled or radiused and the pins  90  themselves are deburred. 
     The cone angle of the sides of the frustums  91  and  93  fixes the maximum bend angle between adjacent pairs of hinge tracks  84 , preventing the articulating column  81  from bending too much in one direction or another. Because the limiting pins  90  are symmetric about the longitudinal axis of the column  81 , they permit universal axial motion (i.e., rotation) about the longitudinal axis of the column  81 . 
     Each ball joint  94  is disposed between a respective pair of neighboring hinge tracks  84  in seats  344  aft of the limiting pin recesses  340  and forward of batten guides  302  shown in FIGS.  3 B and  6 A-C. The ball joints  94  receive a tensioning line  86  that runs through the column  81  via holes along the diameters of the ball joints  94 .  FIG. 5  is illustrative of the holes along the ball joint  94  diameter. Like the limiting pins  90 , the ball joints  94  may be formed of nylon that has a low coefficient of thermal expansion, high strength, and high rigidity, such as Nylatron GS. Typically, the edges of the ball joints  94  are beveled or radiused and the ball joints  94  themselves are deburred. 
     The tensioning line  86  may be a flexible wire, cable, rod, synthetic rope, or any other suitable line or cable. As shown in  FIG. 3A , the tensioning line  86  includes a threaded end  87  that receives a nut  88 . Increasing the tension on the tensioning line  86  by tightening the nut  88  presses (vertically compresses) the hinge tracks  84  together, reducing the column&#39;s range of motion. Conversely, reducing the tension on the tensioning line  86  by loosening the nut  88  relieves pressures on the hinge tracks  84 , increasing the column&#39;s range of motion. Other embodiments may includes other tensioning means such as hydraulic or pneumatic cylinders arranged at the upper end, lower end, or both ends of the tensioning line  86 . 
     FIGS.  3 B and  6 A-C show the cross section  300  of the hinge of a hinge track  84 ; this cross section  300  is also known as a luff extrusion. A hinge track  84  with the luff extrusion cross section  300  shown in  FIG. 3B  solves the problem of batten poke or chafing by providing a batten guide  302  that receives battens along the length of the mast  20 , such as the full battens  32  shown in  FIG. 1 . The present inventive hinge track cross section  300  also eliminates problems associated with friction-locked sail slides by providing a channel  310  for a headboard car  28  ( FIG. 1 ) that eliminates the need for sail slides. 
     The hinge track cross section  300  includes a pair of substantially parallel batten guide arms  304  that form the batten guide  302 . A luff passage  306  connects the batten guide  302  to a luff rope slot  308  configured to hold a luff rope sewn into the luff  36  of the sail  30 . As wind fills the sail  30 , compressing the battens  32  ( FIG. 1 ), the battens  32  push against the forward edge of the batten guide  302 , reducing chafing on the sail bolt rope. The batten guide arms  304  also stabilize battens  32  subject to rotational forces. The upper and lower surfaces of the batten guide arms  304  are also beveled slightly (e.g., by 2.5°) in one embodiment shown in  FIG. 6C  to allow the articulating column  81  to bend and flex along the plane of the sail  30 . 
     The cross section  300  also includes a hinge pin tunnel  340  configured to receive limiting pins  90  and a ball seat  344  configured to receive ball joints  94 . Each hinge track  84  has a connector tunnel  342  that connects the upper and lower ball seats  344 , as shown in  FIG. 6C . The tunnels  340  and  342  may extend through the entire thickness of the hinge track  84  with a constant shape and size. Alternatively, they may be configured to have upper and lower receptacles to prevent neighboring limiting pins  90  and ball joints  94  from touching each other. 
     As shown in  FIG. 3B , the headboard car channel  310  is formed substantially next to (i.e., abeam of) the luff rope slot  308 , defining a travel axis for the headboard car  28  ( FIG. 1 ) that is substantially coincident with the axis formed by the luff rope slot  308 . Because the headboard car  28  and the luff rope (not shown) travel along the same axis, torque on the headboard car  28  or the headboard  29  ( FIG. 1 ) in the plane of the sail  30  is less likely to cause the headboard car  28  to shift, jam, or stick in the headboard car channel  310 . As a result, the luff rope and headboard car  28  travel freely up and down an axis parallel to the longitudinal axis of the mast  20 . 
     In a preferred embodiment, the hinge tracks  84  are each about five and a half inches long, about two inches high, and vary in width from just under two inches just forward of the headboard car channel  28  to about one and a quarter inches at the channel  28  itself. The headboard car channels  310  are each about seven-eighths of an inch wide and about one-quarter inch deep. The batten guide arms  304  are just under one and three-quarters inch long, forming a batten guide  302  of same length and a width of about one inch. The luff passage  306  may be about one-fifth of an inch wide and about one-quarter of an inch long. The luff rope slot  308  has a radius of about three-tenths of an inch. Edges of hinge tracks  84  with the present inventive luff extrusion cross section  300  may be beveled, chamfered, and/or radiused as appropriate. 
       FIGS. 7A-B  shows a bottom hinge track  85  of the articulating sail feeder  80  shown in  FIGS. 2 and 3 . Like the hinge tracks  84 , the bottom hinge track  85  has a luff extrusion cross section  300  with batten guide arms  304  that form a batten guide  302 , which is connected to a luff rope slot  308  by a luff passage  306 . The bottom hinge track  85  has only one ball seat  344 , located on the upper surface of the bottom hinge track  85 . The tensioning line  86  runs through the ball joint  94  (not shown) and connector tunnel  342  and terminates in a cavity  185  in the bottom hinge track  85 . 
     The cavity  185  accommodates tensioning means attached to the lower end of the tensioning line  86  for adjusting the tension of the tensioning line  86 . For example, the tensioning means may include a nut  88  ( FIG. 2 ) attached to a threaded tensioning line  86  or hydraulic or pneumatic cylinders. Increasing the tension decreases the articulating sail feeder&#39;s range of motion; decreasing the tension increases the articulating sail feeder&#39;s range of motion. In preferred embodiments, the cavity  185  is about three inches high by one and a half inches long; the cavity&#39;s upper edge is about seven inches from the upper edge of the bottom hinge track  85 . The bottom hinge track  85  is about one foot, one-quarter inch high, by about five and a half inches long, by about two inches wide at its widest point. 
     The hinge tracks  84  and bottom hinge track  85  may be fabricated of carbon fiber, 6005 aluminum alloy, or any other suitable material. Generally, suitable materials are at least moderately strong; capable of bending, flexing and twisting; suitable for machining, welding, and brazing; and corrosion resistant (or able to be treated or coated with corrosion-resistant material). For example, the hinge tracks  84  may have a clear anodized finish. Hinge tracks  84  and bottom hinge tracks  85  may be made by machining, extrusion, or any other suitable manufacturing technique. 
       FIGS. 8A-E  are views from different perspectives of a feeder  82  configured to be coupled to the lower end of the bottom hinge track  85  as shown in  FIG. 2 . The feeder  82  is scoop-shaped to guide the sail through the free space between the articulating sail feeder  80  and the boom  26 . In preferred embodiments, the feeder  82  is about six inches high at its tallest, two inches wide, and just under six inches long. The feeder  82  may be made of any sufficiently strong, corrosion-resistant material, such as grade  316  stainless steel finished with a tumble burnish and/or electrolytic polish. 
       FIGS. 9A and 9B  are, respectively, plan and elevations views of a sail  30 , headboard car  28 , and mast track  24  with the present inventive luff extrusion cross section  300 . The headboard car  28 , which is coupled to the head  38  of a sail  30  via a headboard  29 , includes a guide  452  formed of two substantially parallel arms  454  that fit around the outside of the luff extrusion  300 . The arms  454  on the headboard car  28  have channels  460  that mate with the complementary channels  310  on the luff extrusion  300 . Bearings (not shown) between the channels  310  on the luff extrusion  300  and the channels  460  on the headboard car  28  allow the headboard car  28  to travel freely along an axis substantially parallel to the mast  20  ( FIG. 1 ). 
     Because the headboard car  28  travels smoothly along the bearings between the channels  460  and  310 , the sail  30  can be raised and lowered with a halyard (not shown) attached to the headboard car  28 . In contrast to conventional sails, which are raised with halyards attached directly to the head  38  or the headboard  29 , sails  30  coupled to headboard cars  28  in embodiments of the present invention do not need sail slides to ensure smooth travel of the sail up and down the mast. As a result, sails  30  raised with headboard cars  28  configured with luff extrusions  300  of the present invention do not suffer from the compression- and torque-induced friction that locks sail slides into place. 
     In a preferred embodiment, the headboard car  28  is made of aluminum or any other suitably strong, light, and corrosion-resistant material. The guide  452  is wide enough and long enough to substantially accommodate the luff extrusion  300 . For example, the arms  454  may be about five inches long and spaced about two inches apart. The edges of the headboard car  28  may be beveled, chamfered, and/or radiused as appropriate. 
       FIG. 10  is a plan view of an alternative hinge track cross section  500  with an internal headboard car  528 . The cross section  500  includes a pair of substantially parallel batten guide arms  504  that form a batten guide  502 , which connects to a luff rope slot  508  via a luff passage  506 . Each batten guide arm  504  terminates in a hook shape  512  or similar configuration that defines a headboard car channel  510  inside the batten guide  502 . The internal headboard car  528 , which may be round or disc-shaped (i.e., shaped like a hockey puck), travels in the space defined by the batten guide  502  along an axis defined by the headboard car channel  510 . The hooks  512  retain the headboard car  528  within the batten guide  502 . 
     The batten guide  502  receives battens  32  sewn in the sail below the headboard car  528 . As compressive forces push the battens  32  forward, the battens  32  push against the batten guide  502 , rather than chafing against the forward edges of the sail bolt rope. Similarly, the batten guide arms  504  hold the battens  32  as the battens  32  twist and rotate, reducing friction between the battens  32  and the respective batten pockets  34 . 
     The alternative cross section  500  also includes a connector tunnel  542  and a hinge pin tunnel  540 , which are configured to retain a tensioning line  86  and limiting pins  90 , respectively. The connector  542  may also be configured to receive ball joints  94  with a ball joint seat (not shown). 
     Of course, other configurations of headboard car channels are possible. For example, the headboard car  28  could ride on channels formed by everted channels, protrusions, or rails that stick out from a mast track  24  with the inventive luff extrusion cross section. The channels may include more than two channels on each side, or may be formed further forward or aft along the inventive luff extrusion. The channels may be integral to the cross section or may formed by additional fixing parts to the mast  20  or mast track  24 . 
     While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. 
     For example, the generic term yacht as used herein includes sailing vessels, boats, and ships of various sizes, including mega-yachts, which may be 40 feet or longer. Similarly, the generic term sail includes mainsails, which are used primarily to propel yachts. Likewise, the generic term mast includes mainmasts and other masts. In addition, the terms luff rope, sail bolt rope, and bolt rope may be used interchangeably. 
     Further, the various dimensions, materials, and surface or edge processing are for purposes of non-limiting illustration. Other dimensions, materials, and manufacturing processing are suitable.

Technology Category: b