Abstract:
A sail furler with a recirculating halyard includes a foil having a longitudinal halyard channel and a longitudinal recirculating halyard channel formed within; and a halyard, having a first and second end, the halyard affixed at its first end to a slider, the slider affixed to head of the sail, the halyard rising to an upper end of the foil, leading through a top cap, and then descending downwards through the halyard channel to an exit of the halyard channel in proximity to a lower end of the foil, then ascending through the recirculating halyard channel, and terminating at its second end to the slider, so that the distance between the second halyard end and the head of the sail remains constant whether the sail is raised or lowered.

Description:
FIELD OF THE INVENTION 
   This invention is directed to the field of marine technology, and more specifically to the field of sail-hoisting devices. 
   DESCRIPTION RELATIVE TO THE PRIOR ART 
   Modern yachting has seen dramatic developments in technologies which reduce the drudgery of handling sails in the past several decades. In particular, systems which allow easy furling and reefing of sails have proliferated, allowing a single person to set, reef, furl, and secure sails with a minimum of effort. 
   An invention for furling foresails was described in U.S. Pat. No. 4,821,664, and may be understood by referring to  FIGS. 4 and 11 . This invention provides a foil  1  which contains three channels, wherein the forestay  4  of the sailboat is captured by central tunnel  11 , as seen in the cross-sectional view of the foil as depicted in  FIG. 4 . The foil  1  thus rotates freely about the forestay, and is completely supported by said forestay. This configuration is especially advantageous in the case of sailboats which are trailered, because the furler need not be removed when the mast is stepped or unstepped, or rotated on a tabernacle. 
   Still referring to  FIGS. 4 and 11 , it may be seen that the sail  2  is raised by pulling down on a handle  38 , which is inserted in the forward foil channel  10  and attached within the forward foil channel to the downward portion of the halyard  133 . The halyard progresses upward to the prior art foil cap  105 , where it is led downward again  33 , and finally attaches to the head  28  of the sail. 
   The luff  1  of the sail  2 , has a luff rope or bead formed within, which is captured within the aft sail channel  23  of the foil. 
   The sail  2  is maintained in tension by the downhaul  54 , which is attached to a becket at the clew of the sail  52 , and a rope  40  which attaches at one end to the handle  38 , and is belayed at the other end at a fitting  42 , typically a cleat. Tension on the forestay is adjusted by means of the turnbuckle  50  affixed to the forestay lower end. 
   Unlike many other prior art furlers, the invention described in the &#39;664 patent does not require support from a separate halyard attached to the mast. Instead, the rigidity of the foil is used to counter the tension on the luff of the foresail. The foil, in turn, is reinforced by the forestay, which prevents the foil from bending or bulging, so that the foil need only resist compression to maintain the sail in its proper setting. 
   The present invention is an improvement on the configuration just discussed in that the mechanism of the current invention functions more reliably, provides further safety and security features, is less subject to jamming and does away with the perennial problem of losing the tail end of the halyard when it is attached to a separate rope, as described above. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a staysail furler wherein the halyard is affixed at both ends in proximity to the head of the sail, so that the sailor handling the halyard never handles the bitter end of the halyard. 
   In accordance with a first aspect of the invention a system for furling a sail includes a foil having a longitudinal halyard channel and a longitudinal recirculating halyard channel formed within the foil. 
   In accordance with a second aspect of the invention a halyard, having a first and second end, is affixed at its first end in proximity to the head of the sail. 
   In accordance with a third aspect of the invention, the halyard rises to an upper end of the foil, then descends through the halyard channel to an exit near the lower end of the foil, then ascending through the recirculating halyard channel, and terminates in proximity to the head of the sail. 
   In accordance with a fourth aspect of the invention the distance between the second halyard end and the head of the sail remains constant whether the sail is raised or lowered. 
   In accordance with a fifth aspect of the invention a slider is slidingly disposed about the foil, and has an upper and a lower end, and a fore and aft side. 
   In accordance with a sixth aspect of the invention the head of the sail is affixed at the slider aft side at its lower end, the first end of the halyard is affixed at the slider aft side at its upper end, and the second end of the halyard is affixed at the slider fore side. 
   In accordance with a seventh aspect of the invention a top cap is slidingly disposed upon the upper end of the foil, and has a first exit hole and a second exit hole, wherein the halyard exits from its attachment in proximity to the head of the sail into the first exit hole, and then descends through the second exit hole into the halyard channel. 
   In accordance with an eighth aspect of the invention the foil cap has a worm groove formed thereon, the worm groove communicating between the first exit hole and the second exit hole of the foil cap. 
   In accordance with a ninth aspect of the invention the foil further contains a headstay tunnel which has a lip which prevents the halyard from chafing on a headstay disposed with the headstay tunnel. 
   In accordance with a tenth aspect of the invention further comprising means for belaying the halyard, disposed upon the foil in proximity to the lower end of the foil, close to the location where the halyard exits the halyard channel. 
   In accordance with an eleventh aspect of the invention the second end of the halyard is affixed in proximity to the top end of the slider. 
   In accordance with a twelfth aspect of the invention the second end of the halyard has a de-cored portion and a crimp sleeve affixed to the halyard at the start of the de-cored portion, so that the de-cored portion of the halyard exits from the recirculating halyard channel. 
   In accordance with a thirteenth aspect of the invention the de-cord portion of the halyard is lead through a slider lead slot, into the slide lead, and is then knotted to affix it to the slider. 
   In accordance with a fourteenth aspect of the invention the means for belaying the halyard in proximity to the lower end of the foil consists of a cleat, whereby the halyard is led through the eye of the cleat. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
       FIG. 1  depicts a side elevation view of a sail hoist on a foil of the present invention. 
       FIG. 2  depicts a cross-sectional view of the foil of the present invention. 
       FIG. 3  depicts a perspective view showing detail of the slide, affixed to the foil of the present invention. 
       FIG. 4  depicts a perspective view of the top cap above the foil of the present invention. 
       FIG. 5  depicts a perspective view of the bottom of the foil, with the halyard disposed through the eye of the cleat, above the drum of the present invention. 
       FIG. 6  depicts a perspective view of the tail end of the halyard end of the present invention, with the crimp sleeve affixed and the core-less bitter end shown. 
       FIG. 7  depicts a cross-sectional view of a prior art foil. 
       FIG. 8  depicts a perspective view showing the recirculating halyard within the foil of the present invention. 
       FIG. 9  depicts a perspective view of the top cap of the present invention. 
       FIG. 10  depicts a perspective view of the slide of the present invention. 
       FIG. 11  depicts a cross-section view of a prior art furling system. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The preferred embodiment of the present invention may be understood by first referring to  FIG. 1 , which shows a sail  2  affixed to the aft side of foil  1  at the luff by means of a luff rope or bead  9  which is captured by the luff channel  10 . The luff is maintained in tension at its lower end by affixing the tack  101  of the sail to the top of the drum  8 . Further, the head of the sail is attached to the lower end of slider  6 , which is pulled upward by a first end of halyard  3 . The halyard is affixed at its second end to the forward side of slider  6  after threading its way through the halyard channel  23  and the recirculating halyard channel  24 . 
   The halyard forms a loop as it exits the halyard channel near the bottom of the foil, and then enters the recirculating halyard channel. This loop, in turn, is belayed to the cleat  7  which is affixed to the front of the foil. 
   The presence of the slider  6  in this invention is one of the most obvious distinctions between the present invention and the prior art. The slider, which appears in detail in  FIG. 10 , has the form of a hollow sleeve which has an inner cross section that mates slidingly with the outside of the foil  1 , and therefore moves smoothly up and down on the foil. An upper fitting  27  is affixed to the halyard  3 , while the lower fitting  28  is affixed to the head of the sail. 
   Another major feature of the present invention is the recirculating halyard, which may be understood by referring next to  FIGS. 5 and 8 . The halyard  3 , which is affixed to the upper fitting  27  of the slider  6 , is led upward to the head cap  5  atop the foil, and then downward into the halyard channel until it exits  23  at the open bottom of the halyard channel, is routed through the eye of the cleat  7 , and then ascends into the bottom of the recirculating halyard channel  24 . The halyard continues upward in the recirculating halyard channel  24  until it exits in proximity to the top of the slider, where it is belayed to the fitting at the back of the slider. 
   Referring next to  FIG. 3 , the detail at the top of the slider is shown, with the halyards and other rigging shown. The halyard is seen exiting from the slot of the recirculating halyard channel  24 , where is enters the slider lead  17  through the slider lead slot  16 , as seen in  FIG. 10 . The halyard dead end is terminated at the bottom of the slider lead  17  by means of a figure eight knot, which keeps the dead end secured at the bottom end of the slider lead. 
   In a typical embodiment of the furler, the dead end of the recirculating portion of the halyard is modified to allow it to exit from the external slot  224  of the recirculating halyard channel  24 . A sleeve  19  is crimped onto the tail end of the halyard  30 , leaving a short remaining length of rope  30 , whose core is removed, so that the diameter of this remaining length is substantially reduced, and so that it may easily exit from the slot of the recirculating halyard channel at the forward side of the foil. It is this de-cored length that is formed into a figure eight knot at the dead end of the halyard which affixes the halyard to the slide. The detail of this modification may be seen by referring to  FIG. 6 . 
   The remaining end  30  of the halyard its core removed so that it significantly smaller in diameter than the halyard itself, so that it may exit from the halyard channel  23  of the foil. The crimp sleeve  19  prevents the main body of the halyard from unraveling at the point where the core has been removed, and provides support for the main portion of the halyard  25  at this point. The crimp sleeve  19  may also be seen in the drawing of  FIG. 3 , as it lies within the recirculating halyard channel  24 . This figure also depicts the exit of the coreless portion of the halyard through slider slot  16  at the fore side of the recirculating halyard channel, downward into the slider lead  17 , and out through the bottom of the slider lead, where the coreless portion of the halyard is formed into a figure eight knot at the dead end or bitter end of the halyard. 
     FIG. 3  further shows the halyard  14  attached to the upper fitting  27  at the aft side of the slider by means of a shackle, while a shackle at the lower fitting  26  at the aft side of the slider is affixed to a grommet at the head of the sail  2 . 
   Referring now to  FIG. 9  the top cap  5  of the foil is shown. The headstay tunnel  11  extends into the middle of the top cap, where it appears as top cap forestay hole  111 , and there is a raised lip formed about this hole extending upwards. The headstay is completely enclosed within the headstay tunnel  11 , which provides the main support for the foil, maintaining the foil&#39;s position at or near the bow of the sailboat. The foil must be led through this headstay channel before affixing the headstay to the sailboat. This is typically done by leading the lower end of the headstay through the headstay tunnel, and then affixing the lower end of the headstay to the sailboat. In the preferred embodiment of the present invention a drum  8  is formed at the lower end of the foil, so that the headstay also passes through the drum before being affixed at the bow of the sailboat. 
   The halyard  3  is led upward from its attachment point at the top end of the slider into the first exit hole  112  of the top cap. The halyard then is led downward through the second exit hole  124  into the halyard channel  23 . The recessed worm slot  26  formed between the top cap exit holes directs the halyard across the top of the top cap, and around the headstay channel, so that the halyard is not chafed by contact with the stay. The worm slot is formed with contours providing the halyard a smooth transition from the upward path of the halyard from the sail head, across the top of the top cap, and then downward into the halyard channel, so that friction between the halyard and the top cap is minimized. 
   In alternative embodiments, a pulley or sheave may be used to lead the halyard from the upward portion as it rises from the sail head downward into the channel. Other alternatives are also available for reducing friction and increasing the ease of handling in this regard. 
   Referring now to  FIG. 4 , an exploded view depicts the top cap in relation to the top of the foil. The halyard  3  is seen leading from the head of the sail  31  up into the top cap  5 , and then down into the halyard channel  23  of the foil  1 . 
   The differences between the present invention and the prior art furler depicted in  FIG. 11  also include the cross-sectional shape of the foil. The foil of the present invention, as seen in  FIG. 2 , has an elliptical shape, with the major and minor axes having a ratio of about 1.5 to 1. The prior art foil as seen in  FIG. 7 , on the other hand, has a ration of about 3 to 1 between the major and minor axes. 
   Still referring to  FIG. 2 , it can be seen that the headstay  4  of the sailboat is led through the headstay tunnel  11 , which is sufficiently larger than the headstay so that the foil may rotate freely, depending, of course on other external factors, such as sheet and downhaul, to limit the rotation. The bead or luff rope  9  of the sail  2  is contained within the luff channel  10 . The two halyard channels  12 ,  13  contain the halyard  3 . Each of the halyard channels contain slots  212 ,  213 , which open outward from the halyard channels. The recirculating halyard terminates in a de-cored tail  30  which exits from the side of the recirculating halyard channel  24  through slot  214 , as shown if  FIG. 3 . 
   When attempting to furl the prior art furler of  FIG. 11 , the sail wraps somewhat unevenly about the foil, because of the difference in mechanical advantage when the sail first contacts the long axis of the foil, as opposed to contacting the short axis. The present invention has a foil more nearly round in cross section, and provides a more even pressure of furling as the foil rotates. 
   The present invention further eliminates the worry of losing the handle by having it slide up to the top of the foil if it unties from the belaying rope of the prior art furler of the &#39;664 patent. Because the halyard of the present invention is continuous, there are no loose ends which untie. 
   Furthermore, the use of the slider in the present invention provides further reliability and smoothness of operation. Because the tension on the hoisting  27  and sail attachment points  28  of the slider are equal and opposite, there is no net vertical twisting force on the slider, so that it moves up and down the foil without jamming. Furthermore the force on the head of the sail is always parallel to the foil in the present invention, due to the use of the slider. The present system thus provides unparalleled ease of operation and reliability not available in the prior art. 
   While certain embodiments and examples have been used to describe the present invention, many variations are possible and are within the spirit and scope of the invention. Such variations will be apparent to those skilled in the art upon inspection of the specification and claims herein. Other embodiments are within the following claims.